These slides on management of minor elements in the production of base metals were presented at the Green Processing conference. This paper explores alternative processing options for selective removal of minor elements such as arsenic so as to avoid dispersion of such toxic elements in the biosphere.
The full paper was published through AusIMM conference proceedings.
This document discusses the declining ore grades in Australian mines and the implications for processing routes and energy consumption. As ore grades decrease over time, the energy required for mining and processing increases significantly. Processing routes like heap leaching and direct smelting consume less energy than routes involving concentration and smelting, especially for lower grade ores. The optimal processing route depends on the ore grade and characteristics. Overall, declining ore grades will continue to drive up energy needs for metal production in Australia and globally.
The document examines the potential for reducing carbon dioxide emissions through the use of high volume fly ash cement. It finds that full utilization of fly ash today could achieve reductions of 10-36% but would not be enough to meet reduction targets of 30% by 2020 and 50% by 2050. Alternative cementitious materials beyond fly ash will be needed to achieve sustainability in the cement industry. The location of increased cement demand aligns with areas of increasing coal production, providing opportunities for greater fly ash use.
Marcello M. Veiga, Associate Professor of University of British Columbia, Van...Esther Petrilli-Massey
The document summarizes alternative processes and technical solutions to reduce or replace mercury use in artisanal and small-scale mining operations. It discusses problems with whole ore amalgamation and provides examples of improved amalgamation techniques from various countries that reduce mercury emissions such as using barrels, centrifuges, and additives. It also explores alternative processes like cyanidation, flotation, direct smelting, and electrolysis but notes challenges for artisanal miners. Mill-leaching of gold ore with cyanide during grinding is presented as a potential mercury-free alternative.
This workshop is a deliverable of TRAC project which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement Nº777823.
Presentation 1:
On the Reactivity Mechanism of Supplementary Cementitious Materials by Alkali Activation
Yu Jin, Shenzhen Institute of Information Technology, China
Dr. Yu Jin obtained his Ph.D from Techische Universität Berlin and works currently as an associate researcher at Shenzhen Institute of Information Technology. He is now the member of GDCh Bauchemie (German Chemical Society Construction Chemistry Branch) and reviewer for some prestigious journals like Journal of the American Ceramics Society, Journal of Cleaner Production. He has published 19 journal papers, including those in Cement and Concrete Research, Journal of Cleaner Production. His research interest covers the ultlization of solid waste, alkali activated materials, latex modified cement based materials.
S. Al-Hassan & R. K. Amankwah & R. S. Nartey, University of Mines and Technol...Esther Petrilli-Massey
Direct smelting of gold concentrates is proposed as an alternative to mercury amalgamation for small-scale gold mining in Ghana. Laboratory and field tests showed direct smelting recovered 99.9% of gold compared to 97% for amalgamation. It is cheaper and does not use hazardous mercury. Challenges include developing alternatives to charcoal fuel and improving crucible integrity for processing different concentrate types. Direct smelting is presented as a viable replacement for amalgamation in small-scale gold mining.
This document describes direct smelting as an alternative to mercury amalgamation for artisanal and small-scale gold mining in Ghana. Direct smelting involves melting gold-bearing concentrates using borax, sodium carbonate and silica sand as fluxes to separate pure gold. The technique was tested in the lab and field and found to recover over 99% of gold, compared to 88-97% for amalgamation. It is presented as an effective, simple, quick and affordable non-toxic alternative suitable for small-scale operations. Challenges to adoption include ensuring continued availability and affordability of equipment kits for miners.
This document discusses research on utilizing red mud and fly ash to produce geopolymer materials. Laboratory studies showed that combining red mud and fly ash allows for the formation of sialate and ferro-sialate structures, resulting in geopolymer composites with good mechanical properties and durability. Pilot scale trials produced paving tiles containing 20% red mud that met Indian standards and performed comparably to conventional cement-based tiles at a lower environmental impact. A 100 ton/day commercial plant was proposed that could reuse over 400 kg of waste materials per ton of tiles produced.
Hydrogenation of sugars over supported metal catalyst - effect of supportpbpbms6
The document describes hydrogenation of sugars like xylose and glucose over supported metal catalysts to produce sugar alcohols. Pt/γ-Al2O3+HT catalytic system showed the highest activity, yielding up to 82% of C5 sugar alcohols and 68% of C6 sugar alcohols. The activity was governed by the interaction of the metal and support, as well as the support's acidic or basic properties. Catalyst characterization showed the Pt particles were well dispersed and stabilized on basic supports like hydrotalcite.
This document discusses the declining ore grades in Australian mines and the implications for processing routes and energy consumption. As ore grades decrease over time, the energy required for mining and processing increases significantly. Processing routes like heap leaching and direct smelting consume less energy than routes involving concentration and smelting, especially for lower grade ores. The optimal processing route depends on the ore grade and characteristics. Overall, declining ore grades will continue to drive up energy needs for metal production in Australia and globally.
The document examines the potential for reducing carbon dioxide emissions through the use of high volume fly ash cement. It finds that full utilization of fly ash today could achieve reductions of 10-36% but would not be enough to meet reduction targets of 30% by 2020 and 50% by 2050. Alternative cementitious materials beyond fly ash will be needed to achieve sustainability in the cement industry. The location of increased cement demand aligns with areas of increasing coal production, providing opportunities for greater fly ash use.
Marcello M. Veiga, Associate Professor of University of British Columbia, Van...Esther Petrilli-Massey
The document summarizes alternative processes and technical solutions to reduce or replace mercury use in artisanal and small-scale mining operations. It discusses problems with whole ore amalgamation and provides examples of improved amalgamation techniques from various countries that reduce mercury emissions such as using barrels, centrifuges, and additives. It also explores alternative processes like cyanidation, flotation, direct smelting, and electrolysis but notes challenges for artisanal miners. Mill-leaching of gold ore with cyanide during grinding is presented as a potential mercury-free alternative.
This workshop is a deliverable of TRAC project which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement Nº777823.
Presentation 1:
On the Reactivity Mechanism of Supplementary Cementitious Materials by Alkali Activation
Yu Jin, Shenzhen Institute of Information Technology, China
Dr. Yu Jin obtained his Ph.D from Techische Universität Berlin and works currently as an associate researcher at Shenzhen Institute of Information Technology. He is now the member of GDCh Bauchemie (German Chemical Society Construction Chemistry Branch) and reviewer for some prestigious journals like Journal of the American Ceramics Society, Journal of Cleaner Production. He has published 19 journal papers, including those in Cement and Concrete Research, Journal of Cleaner Production. His research interest covers the ultlization of solid waste, alkali activated materials, latex modified cement based materials.
S. Al-Hassan & R. K. Amankwah & R. S. Nartey, University of Mines and Technol...Esther Petrilli-Massey
Direct smelting of gold concentrates is proposed as an alternative to mercury amalgamation for small-scale gold mining in Ghana. Laboratory and field tests showed direct smelting recovered 99.9% of gold compared to 97% for amalgamation. It is cheaper and does not use hazardous mercury. Challenges include developing alternatives to charcoal fuel and improving crucible integrity for processing different concentrate types. Direct smelting is presented as a viable replacement for amalgamation in small-scale gold mining.
This document describes direct smelting as an alternative to mercury amalgamation for artisanal and small-scale gold mining in Ghana. Direct smelting involves melting gold-bearing concentrates using borax, sodium carbonate and silica sand as fluxes to separate pure gold. The technique was tested in the lab and field and found to recover over 99% of gold, compared to 88-97% for amalgamation. It is presented as an effective, simple, quick and affordable non-toxic alternative suitable for small-scale operations. Challenges to adoption include ensuring continued availability and affordability of equipment kits for miners.
This document discusses research on utilizing red mud and fly ash to produce geopolymer materials. Laboratory studies showed that combining red mud and fly ash allows for the formation of sialate and ferro-sialate structures, resulting in geopolymer composites with good mechanical properties and durability. Pilot scale trials produced paving tiles containing 20% red mud that met Indian standards and performed comparably to conventional cement-based tiles at a lower environmental impact. A 100 ton/day commercial plant was proposed that could reuse over 400 kg of waste materials per ton of tiles produced.
Hydrogenation of sugars over supported metal catalyst - effect of supportpbpbms6
The document describes hydrogenation of sugars like xylose and glucose over supported metal catalysts to produce sugar alcohols. Pt/γ-Al2O3+HT catalytic system showed the highest activity, yielding up to 82% of C5 sugar alcohols and 68% of C6 sugar alcohols. The activity was governed by the interaction of the metal and support, as well as the support's acidic or basic properties. Catalyst characterization showed the Pt particles were well dispersed and stabilized on basic supports like hydrotalcite.
LCA based determination of energy requirement for processing and extraction of low grade copper ores by a range of alternative processes covering both hydro and pyrometallurgy. The scenarios include direct converting of ores with waste heat recovery from molten slag through dry granulation technology.
Leaching kinetics of powdered pcb of mobile phones in hno3 mediumeSAT Journals
Abstract Printed circuit board (PCB) of mobile phones is leached in nitric acid (HNO3) to extract the valuable metals present in PCB into
the leaching solution. PCB powder is characterized by XRD analysis before and after leaching to identify the metallic phases
present in it. It is found that precious metals gold (Au), silver (Ag), platinum (Pt), copper (Cu), lead (Pb), nickel (Ni) are present
in the powder PCB before leaching. The leached solution is characterized by atomic absorption spectrometer (AAS). 0.0228% Pb,
0.0448% Fe and 0.047% Cu are extracted in the solution. The leaching kinetics is also studied. Activation energy of the reaction
is calculated 23 KJ which suggest that the leaching reaction is diffusion controlled.
Keywords: PCB, Leaching Kinetics, XRD Analysis, AAS
This document discusses dopant diffusion, which is the process of introducing controlled amounts of chemical impurities into a semiconductor lattice. Dopant diffusion is used to form source, drain, base, and emitter regions in semiconductor devices. The document covers various diffusion techniques and parameters, including diffusion sources, solid solubility limits, Fick's laws of diffusion, analytical solutions to the diffusion equations, design of diffused layers, and an example design calculation for a boron diffusion process.
The key processes involved in IC manufacturing on the wafer include diffusion, ion implantation, photolithography, deposition, and etching. Specifically, diffusion and ion implantation are used to introduce impurities into silicon to control conductivity by either thermal diffusion of dopant atoms into silicon or injection of energetic dopant ions. Fick's first and second laws of diffusion describe diffusion quantitatively, where the flux of diffusing particles is proportional to the concentration gradient according to the first law, and the second law relates the change in concentration over time to the divergence of the flux.
This document discusses release kinetics and various drug release mechanisms and models. It begins by outlining the objectives of studying release kinetics, including predicting in vitro release and release profiles. It then covers key topics like modified Noyes-Whitney equation, drug release mechanisms, and theoretical models for diffusion, swelling, and erosion controlled systems. Specific models discussed in detail include zero order, first order, Hixson-Crowell, and various swelling and erosion models. The document provides information on interpreting release kinetics data using these mathematical models.
Here are the answers to 4 questions from the list:
1. Methods to determine interfacial tension:
- Drop weight method: In this method, a drop of liquid is formed at the end of a capillary tube immersed in another liquid medium. The weight of the drop is measured which is directly proportional to the interfacial tension.
- Du Nouy ring method: In this method, a platinum ring is immersed in the liquid and then pulled out. The force required to detach the ring from the liquid surface is measured which is directly proportional to the interfacial tension.
2. Factors influencing rate of reaction: The factors that influence the rate of a chemical reaction include concentration, temperature, pressure
This document discusses diffusion and alloys in materials science. It defines diffusion as the movement of atoms in solids and describes mechanisms like vacancy and interstitial diffusion. Fick's laws of diffusion relating flux and concentration gradients are also covered. The document then discusses alloys, defining them as mixtures of elements and describing types like substitutional and interstitial solid solutions as well as intermetallic compounds. Rules for solid solubility like the Hume-Rothery rules are summarized. Superalloys are mentioned as high strength alloys that retain properties at high temperatures through mechanisms like grain boundary control.
Thorncliffe School aims to raise standards across subjects by improving teaching and learning. Physical Education is the specialist subject, and English recently became the second target subject. The plan outlines goals in four areas:
1) Achievement, teaching, and developing project-based work and qualifications in target subjects.
2) Monitoring student progress and intervention strategies in accredited PE courses.
3) Developing community links and primary school collaboration through leadership programs.
4) Using performance management to develop leadership skills and improve faculty work through new projects.
The overall goal is to boost attainment in target subjects and qualifications by improving teaching, monitoring, and student support across subjects and the community.
This document promotes a creative agency called SenesesMidney that offers a wide range of design services including magazine layouts, website design, movie posters, photography, event planning, and social media management. SenesesMidney asks the reader to envision their design needs and then invites them to work with the agency to bring their creative visions to life.
The document discusses the technologies used to create a video project. It describes using Final Cut Pro for video editing, including tools for cutting, selecting, and adding audio. GarageBand was also used to add music, but a different song was found online. Other technologies discussed include using an iMac computer to access Final Cut Pro and the internet, a camera to record video clips, a tripod to get steady shots, and various websites used for research, presentations, and storing files such as YouTube, Prezi, PowerPoint Online, SlideShare, OneDrive, and Mahara.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise boosts blood flow, releases endorphins, and promotes changes in the brain which help regulate emotions and stress levels.
The Kokkolan University consortium Chydenius offers continuing education courses leading to a Master of Education degree and qualification as a primary school teacher. It is the only permanent program of its kind in Finland. The education uses cooperative learning and small group work. Each year around 40 students are divided into groups A and B to begin their studies in January. This study examines the effects of a drama education course on the grouping process. Research methods include student experiences and the 11 theses of drama education according to Heikkinen. Student feedback highlights the importance of aesthetic doubling, serious playfulness, artistic expression, fun, and social interaction in strengthening the grouping process.
This document summarizes a research project that develops a tool to cluster and visualize Internet outage events from log data using time-series analysis. The tool uses a MapReduce algorithm that runs in O(n log n) time to cluster outage blocks based on their start and end times. The data is partitioned into bins and processed in parallel on Hadoop. An evaluation shows that smaller bin sizes help reduce the maximum number of blocks in each bin, improving the tool's ability to handle bursts of outage events.
El documento presenta información sobre los libros de contabilidad de Andrea Cecilia Montañez Chipana, incluyendo el Libro de Inventario y Balances, Libro Diario, Libro Mayor, Registro de Compras y Registro de Ventas. El Registro de Compras y Registro de Ventas son libros auxiliares obligatorios que requieren el registro detallado y cronológico de las compras y ventas de la empresa respaldadas por documentos como facturas y boletas de venta.
Este documento describe una nueva universidad online y de bajo costo dirigida a hispanohablantes. Ofrece varios programas de grado y posgrado, así como cursos de formación profesional y continua en diversas áreas como criminología, idiomas, negocios y derecho. También presenta eventos de bienvenida para nuevos estudiantes con diferentes tipos de entradas según los días de asistencia y precios dependiendo de la fecha de compra.
Mary Ann Galli offers graphic design services including magazine spreads, social media marketing, web page design, event fliers, typography, movie posters, slide design, and photographic studies. She wants to help customers magnify possibilities through her design work.
30 Radical Things I want my Daughter to know by Heart and by SpiritCharnita Arora
<here>
In my journey as a Wellbeing Coach at Perfect Life Spot (PLS), my role is often that of a nurturer. And since most of our participants are young women, I feel like a mother. In fact, I can already imagine having a daughter someday and feeling like I already know how it feels to be a mother.
“What if I could create a life-manual of sorts; something like a clear yet precise catalog of ideas and practices to guide her…”, I have often delightfully wondered. May be even like some version of Randy Pausch’s The Last Lecture. And so, this post is a result of a delightful wandering and wondering. It emerges from my own real-time experience of being a young female entrepreneur in India navigating through life on her own terms.
Here are 30 radical things that I want my daughter to know by heart and by spirit for creating a wholesome life.
Please note that these points stand valid for all the genders.
Original post: https://medium.com/@arora.charnita/30-radical-things-i-want-my-daughter-to-know-by-heart-a7550962f03f#.j32g33xfu
Software para diagnostico, optimizacion y utileriaqmaicol3
Este documento resume varias herramientas de software gratuitas para diagnosticar, optimizar y realizar tareas de mantenimiento en un PC. Algunas de estas herramientas incluyen HD Tune Pro para medir el rendimiento y estado de salud de los discos duros, PCMark 7 para realizar pruebas integrales de rendimiento del hardware y software, y MemTest86 para diagnosticar problemas con la memoria RAM. Otras herramientas mencionadas ayudan a limpiar el registro de Windows, optimizar el sistema, administrar procesos, ver especificaciones del hardware,
Characterization and reuse avenues of bof slag as flux material in sinterIJARIIT
The present study “Characterization and Reuse avenues of BOF Slag as a flux material in sinter” are focused on waste
utilization for a sustainable growth and development. In an integrated steel plant, approximately 2-4 tonnes of wastes (including
solid, liquid and gas) are generated for every tonne of steel produced. Among all the wastes, slag generated at iron making and
steel making units are a key area of concern. With increasing capacities, the mechanism for disposal of large quantities of slag
that get generated have gained traction as the environmental issues that it could evoke could become critical for steel makers.
Over the last few years, with better understanding process there is a significant reduction in the volume of slag generated.
However, slag generation remains inevitable and emphasis on its recycling remains one of the most serious concerns that need
to be solved. Blast furnace granulated slag is a glassy aggregate and used as raw material for pozzolanic cement. But BOF
granulated slag is crystalline and less glassy phase compared to BF slag, so 100 % utilization as pozzalanic cement manufacture
is limited. Hence, alternate reuse avenues are under study at research or implementation level. The present topic is selected to
study the reuse avenues of BOF Slag as a flux material in sinter.
LCA based determination of energy requirement for processing and extraction of low grade copper ores by a range of alternative processes covering both hydro and pyrometallurgy. The scenarios include direct converting of ores with waste heat recovery from molten slag through dry granulation technology.
Leaching kinetics of powdered pcb of mobile phones in hno3 mediumeSAT Journals
Abstract Printed circuit board (PCB) of mobile phones is leached in nitric acid (HNO3) to extract the valuable metals present in PCB into
the leaching solution. PCB powder is characterized by XRD analysis before and after leaching to identify the metallic phases
present in it. It is found that precious metals gold (Au), silver (Ag), platinum (Pt), copper (Cu), lead (Pb), nickel (Ni) are present
in the powder PCB before leaching. The leached solution is characterized by atomic absorption spectrometer (AAS). 0.0228% Pb,
0.0448% Fe and 0.047% Cu are extracted in the solution. The leaching kinetics is also studied. Activation energy of the reaction
is calculated 23 KJ which suggest that the leaching reaction is diffusion controlled.
Keywords: PCB, Leaching Kinetics, XRD Analysis, AAS
This document discusses dopant diffusion, which is the process of introducing controlled amounts of chemical impurities into a semiconductor lattice. Dopant diffusion is used to form source, drain, base, and emitter regions in semiconductor devices. The document covers various diffusion techniques and parameters, including diffusion sources, solid solubility limits, Fick's laws of diffusion, analytical solutions to the diffusion equations, design of diffused layers, and an example design calculation for a boron diffusion process.
The key processes involved in IC manufacturing on the wafer include diffusion, ion implantation, photolithography, deposition, and etching. Specifically, diffusion and ion implantation are used to introduce impurities into silicon to control conductivity by either thermal diffusion of dopant atoms into silicon or injection of energetic dopant ions. Fick's first and second laws of diffusion describe diffusion quantitatively, where the flux of diffusing particles is proportional to the concentration gradient according to the first law, and the second law relates the change in concentration over time to the divergence of the flux.
This document discusses release kinetics and various drug release mechanisms and models. It begins by outlining the objectives of studying release kinetics, including predicting in vitro release and release profiles. It then covers key topics like modified Noyes-Whitney equation, drug release mechanisms, and theoretical models for diffusion, swelling, and erosion controlled systems. Specific models discussed in detail include zero order, first order, Hixson-Crowell, and various swelling and erosion models. The document provides information on interpreting release kinetics data using these mathematical models.
Here are the answers to 4 questions from the list:
1. Methods to determine interfacial tension:
- Drop weight method: In this method, a drop of liquid is formed at the end of a capillary tube immersed in another liquid medium. The weight of the drop is measured which is directly proportional to the interfacial tension.
- Du Nouy ring method: In this method, a platinum ring is immersed in the liquid and then pulled out. The force required to detach the ring from the liquid surface is measured which is directly proportional to the interfacial tension.
2. Factors influencing rate of reaction: The factors that influence the rate of a chemical reaction include concentration, temperature, pressure
This document discusses diffusion and alloys in materials science. It defines diffusion as the movement of atoms in solids and describes mechanisms like vacancy and interstitial diffusion. Fick's laws of diffusion relating flux and concentration gradients are also covered. The document then discusses alloys, defining them as mixtures of elements and describing types like substitutional and interstitial solid solutions as well as intermetallic compounds. Rules for solid solubility like the Hume-Rothery rules are summarized. Superalloys are mentioned as high strength alloys that retain properties at high temperatures through mechanisms like grain boundary control.
Thorncliffe School aims to raise standards across subjects by improving teaching and learning. Physical Education is the specialist subject, and English recently became the second target subject. The plan outlines goals in four areas:
1) Achievement, teaching, and developing project-based work and qualifications in target subjects.
2) Monitoring student progress and intervention strategies in accredited PE courses.
3) Developing community links and primary school collaboration through leadership programs.
4) Using performance management to develop leadership skills and improve faculty work through new projects.
The overall goal is to boost attainment in target subjects and qualifications by improving teaching, monitoring, and student support across subjects and the community.
This document promotes a creative agency called SenesesMidney that offers a wide range of design services including magazine layouts, website design, movie posters, photography, event planning, and social media management. SenesesMidney asks the reader to envision their design needs and then invites them to work with the agency to bring their creative visions to life.
The document discusses the technologies used to create a video project. It describes using Final Cut Pro for video editing, including tools for cutting, selecting, and adding audio. GarageBand was also used to add music, but a different song was found online. Other technologies discussed include using an iMac computer to access Final Cut Pro and the internet, a camera to record video clips, a tripod to get steady shots, and various websites used for research, presentations, and storing files such as YouTube, Prezi, PowerPoint Online, SlideShare, OneDrive, and Mahara.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise boosts blood flow, releases endorphins, and promotes changes in the brain which help regulate emotions and stress levels.
The Kokkolan University consortium Chydenius offers continuing education courses leading to a Master of Education degree and qualification as a primary school teacher. It is the only permanent program of its kind in Finland. The education uses cooperative learning and small group work. Each year around 40 students are divided into groups A and B to begin their studies in January. This study examines the effects of a drama education course on the grouping process. Research methods include student experiences and the 11 theses of drama education according to Heikkinen. Student feedback highlights the importance of aesthetic doubling, serious playfulness, artistic expression, fun, and social interaction in strengthening the grouping process.
This document summarizes a research project that develops a tool to cluster and visualize Internet outage events from log data using time-series analysis. The tool uses a MapReduce algorithm that runs in O(n log n) time to cluster outage blocks based on their start and end times. The data is partitioned into bins and processed in parallel on Hadoop. An evaluation shows that smaller bin sizes help reduce the maximum number of blocks in each bin, improving the tool's ability to handle bursts of outage events.
El documento presenta información sobre los libros de contabilidad de Andrea Cecilia Montañez Chipana, incluyendo el Libro de Inventario y Balances, Libro Diario, Libro Mayor, Registro de Compras y Registro de Ventas. El Registro de Compras y Registro de Ventas son libros auxiliares obligatorios que requieren el registro detallado y cronológico de las compras y ventas de la empresa respaldadas por documentos como facturas y boletas de venta.
Este documento describe una nueva universidad online y de bajo costo dirigida a hispanohablantes. Ofrece varios programas de grado y posgrado, así como cursos de formación profesional y continua en diversas áreas como criminología, idiomas, negocios y derecho. También presenta eventos de bienvenida para nuevos estudiantes con diferentes tipos de entradas según los días de asistencia y precios dependiendo de la fecha de compra.
Mary Ann Galli offers graphic design services including magazine spreads, social media marketing, web page design, event fliers, typography, movie posters, slide design, and photographic studies. She wants to help customers magnify possibilities through her design work.
30 Radical Things I want my Daughter to know by Heart and by SpiritCharnita Arora
<here>
In my journey as a Wellbeing Coach at Perfect Life Spot (PLS), my role is often that of a nurturer. And since most of our participants are young women, I feel like a mother. In fact, I can already imagine having a daughter someday and feeling like I already know how it feels to be a mother.
“What if I could create a life-manual of sorts; something like a clear yet precise catalog of ideas and practices to guide her…”, I have often delightfully wondered. May be even like some version of Randy Pausch’s The Last Lecture. And so, this post is a result of a delightful wandering and wondering. It emerges from my own real-time experience of being a young female entrepreneur in India navigating through life on her own terms.
Here are 30 radical things that I want my daughter to know by heart and by spirit for creating a wholesome life.
Please note that these points stand valid for all the genders.
Original post: https://medium.com/@arora.charnita/30-radical-things-i-want-my-daughter-to-know-by-heart-a7550962f03f#.j32g33xfu
Software para diagnostico, optimizacion y utileriaqmaicol3
Este documento resume varias herramientas de software gratuitas para diagnosticar, optimizar y realizar tareas de mantenimiento en un PC. Algunas de estas herramientas incluyen HD Tune Pro para medir el rendimiento y estado de salud de los discos duros, PCMark 7 para realizar pruebas integrales de rendimiento del hardware y software, y MemTest86 para diagnosticar problemas con la memoria RAM. Otras herramientas mencionadas ayudan a limpiar el registro de Windows, optimizar el sistema, administrar procesos, ver especificaciones del hardware,
Characterization and reuse avenues of bof slag as flux material in sinterIJARIIT
The present study “Characterization and Reuse avenues of BOF Slag as a flux material in sinter” are focused on waste
utilization for a sustainable growth and development. In an integrated steel plant, approximately 2-4 tonnes of wastes (including
solid, liquid and gas) are generated for every tonne of steel produced. Among all the wastes, slag generated at iron making and
steel making units are a key area of concern. With increasing capacities, the mechanism for disposal of large quantities of slag
that get generated have gained traction as the environmental issues that it could evoke could become critical for steel makers.
Over the last few years, with better understanding process there is a significant reduction in the volume of slag generated.
However, slag generation remains inevitable and emphasis on its recycling remains one of the most serious concerns that need
to be solved. Blast furnace granulated slag is a glassy aggregate and used as raw material for pozzolanic cement. But BOF
granulated slag is crystalline and less glassy phase compared to BF slag, so 100 % utilization as pozzalanic cement manufacture
is limited. Hence, alternate reuse avenues are under study at research or implementation level. The present topic is selected to
study the reuse avenues of BOF Slag as a flux material in sinter.
The document discusses solid waste management in primary steelmaking. It outlines the types and sources of solid waste generated from various processes, including blast furnace slag, steel slag, dust, and mill scale. It also describes methods for recycling and reusing waste materials, such as utilizing blast furnace slag in cement production, road construction, and soil conditioning. The high levels of solid waste generated are a challenge, but proper waste management through recycling and reuse is important for sustainable growth of the steel industry.
ONSHORE PROCESSING OF NODULES. A REVIEW OF METALLURGICAL FLOWSHEETS AND ACTI...iQHub
On Shore Processing of Polymetallic Nodules
The document discusses several metallurgical flowsheet options being considered for processing polymetallic nodules recovered from the seafloor on shore. These include pyrometallurgical/hydrometallurgical processes involving smelting and acid leaching proposed by The Metals Company, reductive acid leaching using SO2/H2SO4 proposed by GSR, and the Cuprion process involving reductive ammonia leaching developed by Kennecott Copper Corp. Testwork results on nodule samples indicate high recoveries of copper, cobalt, nickel, and manganese are possible using these flowsheets. Future plans involve designing, constructing, and operating integrated
This document discusses using refractory sandstone ores and waste as alternative sources of uranium in Poland. It describes how uranium exploration was historically conducted in southwest Poland and how biotechnology can be used to extract uranium and other rare elements from waste. The document outlines studies that showed organic compounds in shale are the main carriers of uranium in certain deposits. It also details how microbial consortia were isolated that are able to leach uranium from ores and wastes under neutral and acidic conditions, extracting up to 95% of the uranium content. The document concludes by discussing different "green" nanosynthesis methods using fungi, bacteria and plants to produce metal nanoparticles.
This document discusses using refractory sandstone ores and waste as alternative sources of uranium in Poland. It describes how uranium exploration was previously conducted in the region. Biotechnology offers possibilities to extract uranium as a byproduct from other rare element recovery processes. Studies show that organic compounds in shale and sandstone conglomerates are the main carriers of uranium in the region's deposits. The document also examines concentrations of various elements in the deposits and losses during processing. Microbial consortia have been isolated that are able to leach uranium from ores and wastes under neutral and acidic conditions, extracting up to 95% of uranium. "Green" biosynthesis using microbes is presented as an environmentally friendly method of extracting
Siti Khodijah Chaerun is an associate professor who studies recycling metals using microbes and plants. Her educational background includes degrees in environmental engineering and geomicrobiology. She conducts research on using microbes like bacteria and fungi to extract metals from ores, mine wastes, and electronic wastes through bioleaching. Plants can also be used to extract and accumulate metals from contaminated soils through phytomining. This approach has advantages like being environmentally friendly and having potential applications for metal recovery from low-grade ores and mine tailings.
Study of corrosion control effect of H2S scavengers in drilling fluidsMutiu K. Amosa, Ph.D.
Selected environmentally benign iron compounds (synthetic magnetite and ferrous gluconate) have been evaluated as corrosion inhibitors for oil-well steel (N-80) in 50 mg/l sulphide concentration at various pH ranging from 5.5 to 11.5 and at High Temperature, High Pressure (HTHP) conditions by the weight loss method. The test temperatures were 150 °F, 275 °F and 350 °F respectively for pressures of 3 000 psi, 5 000 psi and 6 000 psi. The ferrous complex was found to be a better corrosion inhibitor compared to the synthetic magnetite. It exhibited up to 99.2% inhibition efficiency (IE) when the dose of the scavenger was doubled (i.e. when the sulphide to scavenger ratio was 1:2) irrespective of other factors such as pH, temperature and pressure. Whereas, the synthetic magnetite’s optimum inhibition efficiency (IE) was observed to be up to 75.1% only when the ratio of the sulphide to scavenger was 1:4 at the lowest pH of the experiment (pH 5.5) which is not desirable for a drilling mud. As the pH increases, the inhibition efficiency of the magnetite decreases and found to be lowest at the alkaline pH of 11.5.
IRJET- Experimental Study on Removal of Toxic Metals from Leachate using ...IRJET Journal
The document summarizes an experimental study on using rice husk and fly ash to remove toxic metals from landfill leachate. Leachate from landfills contains large amounts of organic matter and heavy metals that threaten water sources. The study investigated using low-cost rice husk and fly ash as adsorbents for removing chromium, copper, nickel, and other metals from leachate. Results showed that treating rice husk with potassium hydroxide to produce granular activated carbon (GAC) improved adsorption capacity. Testing found GAC most effectively removed metals from leachate, with removal rates of over 80% at pH 6. The study demonstrated that low-cost rice husk and fly ash can effectively
This document summarizes the present status of non-ferrous metal industries in India, with a focus on copper, lead and zinc production. It provides an overview of the manufacturing processes for primary copper, lead and zinc, describing the input materials and outputs in terms of air emissions, process wastes, and other wastes. The key environmental concerns from these industries are mining tailings, fugitive dust emissions, and liquid effluents containing heavy metals. Standards are proposed to limit particulate matter and fluoride emissions from aluminum production facilities.
Non-Ferrous Metal Industries: Present Status and proposed standardsSooraj Garg
The document summarizes the present status of non-ferrous metal industries in India, with a focus on copper, lead and zinc production. It provides an overview of the manufacturing processes for primary copper, lead and zinc, describing the key process steps and associated environmental impacts, such as air emissions and waste generation. Standards for emissions and effluent discharges from non-ferrous metal industries are proposed, with more stringent limits for new plants. Ambient air quality monitoring near non-ferrous metal plants is also discussed.
ANALYSIS OF HYDROGEOCHEMICAL AND MINERALOGICAL CHARACTERISTICS RELATED TO HEA...IRJET Journal
This document analyzes the hydrogeochemical and mineralogical characteristics related to heavy metal attenuation in a stream polluted by acid mine drainage from an underground metal mine. Water and sediment samples were collected from affected and unaffected areas. Chemical analysis showed affected water had low pH, high sulfate concentrations, and high heavy metal levels. Heavy metal concentrations decreased downstream as pH increased. Mineralogical analysis identified iron oxide minerals like schwertmannite and goethite precipitating from acid mine drainage. Sequential extraction showed heavy metals were primarily bound to iron oxide phases farther from the mine, but closer to the mine they were more exchangeable and bound to organic matter. The study concludes acid mine drainage chemistry is controlled by iron mineral transformations and precip
The extraction of zinc(II) from zinc-plating wastewater by liquid-liquid extraction was studied using the commercial extractants di-(2-ethylhexyl)phosphoric acid (D2EHPA) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex® 272), as well as the ionic liquids, Trihexyltetradecylphosphonium bromide (Cyphos® 102), Trihexyltetradecylphosphonium decanoate (Cyphos® 103) and Trihexyltetradecylphosphonium bis(2,4,4- trimethylpentyl)phosphinate (Cyphos® 104), diluted in organic solvents. First, the commercial extractants and the ionic liquids with the most potential were selected based on the results from diluents, modifiers, and stripping solution screening tests. Then, the optimization of extraction and re-extraction (stripping) conditions for each extractant was achieved either by effluent pre-treatment (pH adjustment) to remove iron before liquid-liquid extraction or by adjusting the extractant-to-zinc ratio. Afterward, one commercial extractant and one ionic liquid were selected for further evaluation based on the following parameters: reusability, contact time (kinetic studies), and loading capacity.
Chemical, mineralogical and metallurgical characterization of goethite rich i...IJARIIT
In this paper the influence of structural water present in goethite rich ore fines on sinter properties like mean size, RI,
RDI, TI, AI and microstructure were studied. For this three plant sinters with different basicities (A1, A2 and A3) were
experimentally produced varying the raw mix. From the study on variable basicity, it is found that increased basicity has good
effects on the sinter properties. The desired norms of metallurgical properties for good quality sinter required for large size blast
furnace met with increased tumbler index and decreased abrasion index. The RI is also better in highly fluxed sinter A3 and the
RDI is low. All these are happening due to availability of more free lime and porosity. The mean-size of sinter also increases
with increase of basicity. The reducibility index and RDI of sinter A2 and A3 appear to be similar although there is a variation
in chemistry and basicity, this may be attributed to use of more micro-fines in raw material of sinter A3. The specific consumption
of coke rate is highest for sinter A3 is also due to more micro-fines in raw materials. From the microstructure it is found that in
sinter A1 more magnetite and less ferrites are developed in comparison to A2 and A3. The silicoferrites of calcium and
aluminium (SFCA) developed in sinter A2 and A3 are acicular in structure which provides better strength to the sinter. Also the
porosity is more in case of A2 and A3 which can accelerate the reducibility process.
This document summarizes a study on recycling jarosite waste from zinc production to recover valuable metals. Jarosite is a hazardous waste produced during zinc hydrometallurgy containing metals like zinc, lead, cadmium, and iron. The authors developed a process using sulfation roasting followed by water and brine leaching to selectively extract these metals. They achieved high recovery rates of over 98% for zinc, 99% for cadmium and lead, and 86% for iron through this process. Microstructural analysis showed the jarosite structure becomes finer with increasing roasting temperature. This process provides an environmentally friendly solution for treating hazardous jarosite waste and recovering contained metals.
Influence of Oxidizing Agent on Recovery of Metals Including Gold and Silver ...IRJET Journal
This document summarizes a study on extracting metals like gold, silver, copper, zinc, and nickel from printed circuit boards using mixtures of nitric acid and hydrochloric acid. The study varied the concentration of nitric acid as an oxidizing agent in the acid mixtures to observe its effect on metal extraction. It was found that extraction of all metals increased up to 95-98% as nitric acid concentration increased up to 5%, but extraction dropped to 10% with 100% nitric acid. Extraction was also lower with 100% hydrochloric acid alone. The recovery of different metals depended on the nitric acid concentration in the oxidizing acid mixture.
Synthesis of citrate-capped gold nanoparticles from reduced [AuCl4 ]– on asco...UniversitasGadjahMada
Reductive adsorption of [AuCl4]-– by using ascorbic acid immobilized on Mg/Al hydrotalcite (Mg/Al HT) and synthesis of gold nanoparticles (AuNPs) from the reduced gold using sodium citrate have been conducted. Mg/Al HT was synthesized by co-precipitation method at pH 10 with molar ratio of Mg(II) and Al(III) 2:1. Ascorbic acid (AA) was then immobilized on Mg/Al HT to form hybrid of AA and Mg/Al HT (Mg/Al HT-AA). Mg/Al HT-AA was used to reductively adsorb [AuCl4]– and the formed Au(0) was extracted by using sodium citrate to form citrate-capped AuNPs. The formation of AuNPs from 100 mg/L [AuCl4]– solution removed by 60 mg Mg/Al HT-AA was optimum at pH 5.0, by using 70 mM sodium citrate and 2 h sonication time. This optimum condition was successfully applied to synthesize AuNPs from [AuCl4]– as the leaching product of gold from PCB using aquaregia
The document provides information on nickel/cobalt laterite processes including mineralogy, typical ore compositions, process routes, and examples of operating plants. It describes the key steps in pyrometallurgical processes including ore preparation, drying, calcination/reduction, smelting to produce ferronickel or matte, and refining. The pressure acid leach and reduction roast-ammonia leach hydrometallurgical processes are also briefly covered. Process flowsheets for INCO's nickel operations in Indonesia illustrate ore drying, reduction kilning, electric furnace smelting, and matte converting steps.
This document summarizes a study that investigated the adsorption of lead (Pb) from aqueous solution using modified beech sawdust. Some key findings include:
- Maximum Pb removal efficiency of 91.3% occurred at pH 5, while minimum efficiency of 28.04% occurred at pH 7. Maximum adsorption capacity was 0.3841 mg/g.
- As the initial Pb concentration increased from 1 to 7 mg/L, removal efficiency decreased from 91.3% to 33.88%. Increasing adsorbent dose from 2 to 8 g/L improved removal efficiency from 50% to 97.3%.
- Removal efficiency had a decreasing trend after equilibrium was reached
Emerging Earth Observation methods for monitoring sustainable food productionCIFOR-ICRAF
Presented by Daniela Requena Suarez, Helmholtz GeoResearch Center Potsdam (GFZ) at "Side event 60th sessions of the UNFCCC Subsidiary Bodies - Sustainable Bites: Innovating Low Emission Food Systems One Country at a Time" on 13 June 2024
(Q)SAR Assessment Framework: Guidance for Assessing (Q)SAR Models and Predict...hannahthabet
The webinar provided an overview of the new OECD (Q)SAR Assessment Framework for evaluating the scientific validity of (Q)SAR models, predictions, and results from multiple predictions. The QAF provides assessment elements for existing principles for evaluating models, as well as new principles for evaluating predictions and results. In addition to the principles, assessment elements, and guidance for evaluating each element, the QAF includes a checklist for reporting assessments.
This new Framework provides regulators with a consistent and transparent approach for reviewing the use of (Q)SAR predictions in a regulatory context and increases the confidence to accept alternative methods for evaluating chemical hazards. The OECD worked closely together with the Istituto Superiore di Sanità (Italy) and the European Chemicals Agency (ECHA), supported by a variety of international experts to develop a checklist of criteria and guidance for evaluating each criterion. The aim of the QAF is to help establish confidence in the use of (Q)SARs in evaluating chemical safety, and was designed to be applicable irrespective of the modelling technique used to build the model, the predicted endpoint, and the intended regulatory purpose.
The webinar provided an overview of the project and presented the main aspects of the framework for assessing models and results based on individual or multiple predictions.
Monitor indicators of genetic diversity from space using Earth Observation dataSpatial Genetics
Genetic diversity within and among populations is essential for species persistence. While targets and indicators for genetic diversity are captured in the Kunming-Montreal Global Biodiversity Framework, assessing genetic diversity across many species at national and regional scales remains challenging. Parties to the Convention on Biological Diversity (CBD) need accessible tools for reliable and efficient monitoring at relevant scales. Here, we describe how Earth Observation satellites (EO) make essential contributions to enable, accelerate, and improve genetic diversity monitoring and preservation. Specifically, we introduce a workflow integrating EO into existing genetic diversity monitoring strategies and present a set of examples where EO data is or can be integrated to improve assessment, monitoring, and conservation. We describe how available EO data can be integrated in innovative ways to support calculation of the genetic diversity indicators of the GBF monitoring framework and to inform management and monitoring decisions, especially in areas with limited research infrastructure or access. We also describe novel, integrative approaches to improve the indicators that can be implemented with the coming generation of EO data, and new capabilities that will provide unprecedented detail to characterize the changes to Earth’s surface and their implications for biodiversity, on a global scale.
There is a tremendous amount of news being disseminated every day online about dangerous forever chemicals called PFAS. In this interview with a global PFAS testing expert, Geraint Williams of ALS, he and York Analytical President Michael Beckerich discuss the hot-button issues for the environmental engineering and consulting industry -- the wider range of PFAS contamination sites, new PFAS that are unregulated, and the compliance challenges ahead.
Widespread PFAS contamination requires stringent sampling and laboratory analyses by certified laboratories only -- whether it is for PFAS in soil, groundwater, wastewater or drinking water.
Contact us at York Analytical Laboratories for expert environmental testing with fast turnaround times and client service. We have 4 state-certified laboratories in Connecticut, New York and New Jersey, and 4 client service centers.
P: 800-306-YORK
E: clientservices@YorkLab.com
W: YorkLab.com
A Comprehensive Guide on Cable Location Services Detections Method, Tools, an...Aussie Hydro-Vac Services
Explore Aussie Hydrovac's comprehensive cable location services, employing advanced tools like ground-penetrating radar and robotic CCTV crawlers for precise detection. Also offering aerial surveying solutions. Contact for reliable service in Australia.
Download the Latest OSHA 10 Answers PDF : oyetrade.comNarendra Jayas
Latest OSHA 10 Test Question and Answers PDF for Construction and General Industry Exam.
Download the full set of 390 MCQ type question and answers - https://www.oyetrade.com/OSHA-10-Answers-2021.php
To Help OSHA 10 trainees to pass their pre-test and post-test we have prepared set of 390 question and answers called OSHA 10 Answers in downloadable PDF format. The OSHA 10 Answers question bank is prepared by our in-house highly experienced safety professionals and trainers. The OSHA 10 Answers document consists of 390 MCQ type question and answers updated for year 2024 exams.
Download the Latest OSHA 10 Answers PDF : oyetrade.com
Management of Minor Elements
1. Management of MinorManagement of Minor
Elements in theElements in the
Production of Base MetalsProduction of Base Metals
Sharif Jahanshahi, Warren Bruckard,
Chunlin Chen and Frank Jorgensen Mission: To progressively
eliminate waste and emissions
in the minerals cycle, while
enhancing business
performance and meeting
community expectations
2. Presentation by Sharif Jahanshahi PhD, FAusIMM
Sharif Jahanshahi has over 30 years
experience in R&D across; high temperature
processing of ferrous and base metals,
thermodynamics and kinetics of high
temperature systems, melt chemistry,
process modelling, simulation and
development
Currently consulting for leading global
players in the metallurgical industry through
Meta-Logical Solutions Pty Ltd.
Website: http://www.metalogical.solutions
Email: sharif@metalogical.solutions
3. Green Processing 2006: 5-6 June 3
BackgroundBackground
Australia exports ~ 3 millions of tpa of copper, nickel, lead and
zinc in form of concentrate and refined metals.
Base metal ores contain low levels (1- 104
ppm) of toxic/
hazardous elements (As, Sb, Bi, Cd, Hg, Se, Te…, Th, U)
Clean, coarsely-grained ore bodies becoming depleted
Ore bodies of future becoming more complex, finer-grained and
containing higher amount of minor/toxic elements.
Worldwide industry mines and process 100s million tonnes of
base metal ores each year
Accumulated mass of minor elements in biosphere is
large and could have a significant environmental impact
4. Green Processing 2006: 5-6 June 4
Industry ContextIndustry Context
Minor elements present technical and environmental problems
as well as being costly
Smelters impose treatment charges and penalty payment on
minor elements in concentrates
Governments becoming increasingly sensitive to emissions
Community pressure for more sustainable processing
Smelters setting tighter penalty specifications for minor
elements
Imperative to develop alternative treatments for
selective removal of toxic elements at the mine site
before despatch of concentrate to smelters
5. Green Processing 2006: 5-6 June 5
Options for Dealing with ToxicOptions for Dealing with Toxic
Elements in OresElements in Ores
Primarily determined by mineralogy and grain size
Occurrence - association with other elements
Distribution between phases
For widely and uniformly dispersed minor elements in mineral
phases treatment option is limited
Separation and removal in waste/residue streams produced in metal
extraction
If concentrated in discrete phases, options exists for early
removal by physical and chemical means
Having separated and concentrated the toxic elements,
consideration has to be given to their use or safe disposal
6. Green Processing 2006: 5-6 June 6
ArsenicArsenic
Is one impurity element found in most base metal ores and
concentrates
Lowers metal quality, if not removed from product metal
Contributes to health concerns during metallurgical processing
Causes environmental concerns during disposal of tailings and
wastes
High arsenic levels in an ore can make the deposit economically
unviable
Blending of high and low arsenic concentrates has been
practiced by industry. Can we continue this in the future?
7. Green Processing 2006: 5-6 June 7
Mineralogy ConsiderationMineralogy Consideration
In copper ores arsenic occurs as
Enargite (Cu3AsS4) Tennanite (3Cu2S.As2S3)
Arsenopyrite (FeAsS) Cobaltite (CoAsS)
In nickel systems
Gersdorffite (NiAsS) Niccolite (NiAs)
Arsenopyrite (FeAsS) Cobaltite (CoAsS)
Physical separation of arsenic bearing minerals from non-
arsenic bearing minerals is difficult
Similar specific gravity, non-magnetic, strongly floatable with
conventional collectors etc.
Some As minerals contain high concentration of copper and
nickel e.g. enargite (Cu3AsS4) has 48% Cu
8. Green Processing 2006: 5-6 June 8
Mineral Recovery in 1 minuteMineral Recovery in 1 minute
0
10
20
30
40
50
60
70
80
90
100
-500 -400 -300 -200 -100 0 100 200 300 400 500
Pulp potential (mV vs SHE)
Mineralrecoveryat1min(%)
Enargite (pH 8)
Chalcopyrite (pH 8)
0
10
20
30
40
50
60
70
80
90
100
-500 -400 -300 -200 -100 0 100 200 300 400 500
Pulp potential (mV vs SHE)
Mineralrecoveryat1min(%)
Enargite (pH 8)
Chalcopyrite (pH 8)
Senior et al J. Min Eng. Int, In press
9. Green Processing 2006: 5-6 June 9
Selective RoastingSelective Roasting
Roasting has been used to remove arsenic from ores and
concentrates
A number of treatment options have been developed and
reviewed in literature
Operating windows for selective removal of arsenic from copper
concentrates identified through thermodynamic modelling
11. Green Processing 2006: 5-6 June 11
Effect of Oxygen Supply at 700 CEffect of Oxygen Supply at 700 C
100
80
40
60
20
0
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
O2 : chalcopyrite (mol:mol)
RemovalofArsenic(%)
5.3% As
0.54% As
0.055% As
700 ° C
FeAsO4
100
80
40
60
20
0
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
O2 : chalcopyrite (mol:mol)
RemovalofArsenic(%)
5.3% As
0.54% As
0.055% As
700 ° C
FeAsO4
Nakazawa, Yazawa & Jorgensen Met Trans 30B, 1999
12. Green Processing 2006: 5-6 June 12
Effect of Oxygen Supply at 900 CEffect of Oxygen Supply at 900 C
100
80
40
60
20
0
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
O2 : chalcopyrite (mol:mol)
RemovalofArsenic(%)
5.3% As
0.54%
0.055%
900 °C
100
80
40
60
20
0
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
O2 : chalcopyrite (mol:mol)
RemovalofArsenic(%)
5.3% As
0.54%
0.055%
900 °C
Nakazawa, Yazawa & Jorgensen Met Trans 30B, 1999
13. Green Processing 2006: 5-6 June 13
Arsenic Removal from CopperArsenic Removal from Copper
Concentrate during RoastingConcentrate during Roasting
Smelter Roaster* Temp.
(°C)
Arsenic in
feed
(wt %)
Arsenic
removal
(%)
Sulphur
removal
(%)
US EPA MH 540 0.2 27 -
US EPA FB 540 to 620 0.02 15 -
El Indio MH 720 max. 6.4 >90 56
Saganoseki FB 685 to 705 5 to 6 85 to 90 60 to 70
Lepanto FB 700 1.3 82 60
Oroya MH 700 2.6 76 53
Boliden FB 700 to 720 2 92 56
*MH = multi-hearth and FB = fluidized bed
14. Green Processing 2006: 5-6 June 14
Distribution of As, Bi, Pb duringDistribution of As, Bi, Pb during
SmeltingSmelting
40 45 50 55 60
0
25
50
75
100
T=1573 K
PSO2
=0.1 atm
Iron silicate slag
bBi
Gas
Matte
40 45 50 55 60
0
25
50
75
100
T=1573 K
PSO2
=0.1 atm
Calcium ferrite slag
T=1573 K
PSO2
=0.1 atm
Calcium ferrite slag
eBi
Gas
Matte
wt% Cu in matte
40 45 50 55 60
0
25
50
75
100
T=1573 K
PSO2
=0.1 atm
Iron silicate slag
aAs
Slag
Gas
Matte
Distribution(%)
40 45 50 55 60
0
25
50
75
100
T=1573 K
PSO2
=0.1 atm
Calcium ferrite slag
d
Matte
As
Slag
Gas
Distribution(%)
wt% Cu in matte
40 45 50 55 60
0
25
50
75
100
cT=1573 K
PSO2
=0.1 atm
Iron silicate slag
Pb
Gas
Matte
40 45 50 55 60
0
20
40
60
80
100
fPb
Gas
Matte
wt% Cu in matte
Chen et al Sohn Intl Symp , 2006
15. Green Processing 2006: 5-6 June 15
Simulated FlowsheetSimulated Flowsheet
Converting
1st
& 2nd
Stages
Smelting
Fire-refining
1st
& 2nd
Stages
Copper
Conc
Slag
Slag
Matte
Blister Copper
Anode Copper
Gas
Gas
Gas
Air + Flux
Air + Flux
Air/Methane
16. Green Processing 2006: 5-6 June 16
Arsenic DistributionArsenic Distribution
-- From Concentrate to Anode CopperFrom Concentrate to Anode Copper
0
25
50
75
100
Smelting Convert 1 Convert 2 Fire-ref 1 Fire-ref 2
Processing Step
ArsenicDistribution(%)
Gas
Slag
Matte/ Copper
0.1 wt% As in Conc
Iron silicate slag
17. Green Processing 2006: 5-6 June 17
Arsenic DeportmentArsenic Deportment
- From Concentrate to Anode Copper- From Concentrate to Anode Copper
0
25
50
75
100
Smelting Convert 1 Convert 2 Fire-ref 1 Fire-ref 2
Processing Step
ArsenicDeportment(wt%)
Gas
Slag
Matte/Copper
0.1 wt % As in Conc
Iron silicate slag
18. Green Processing 2006: 5-6 June 18
Copper Production from SulfideCopper Production from Sulfide
OresOres
Ore
Tailing
Dam
Anode
Slimes
Smelting
Air, Flux, Coal Air, Flux
Acid Plant
Concentrate Matte Blister
Anode
Copperr Copper
99.99%
Anode
Slimes
Air, Natural Gas
Air, Flux
Slag
SlagSlagSlag
Acid
Dore Metal (Ag-
Au)
Tailings
Gypsum
Tailing Dam
Tailing
Dam
Flotation Smelting 2-stage
Converting
Fire-refining Electro-
refining
19. Green Processing 2006: 5-6 June 19
Safe Disposal of Toxic ElementsSafe Disposal of Toxic Elements
Production of arsenic and other toxic elements is well in excess
of market demand
Typically concentrated in form of fumes, dross, precipitates and
slags
Disposal of surplus in a safe and environmentally acceptable
manner
Thus conversion to a less hazardous form and longer term
solutions are required
conversion into calcium arsenate, ferric arsenate etc.
encapsulation in concrete or locking in silicate slags
Careful assessment of these options is required
20. Green Processing 2006: 5-6 June 20
The Early Removal OptionsThe Early Removal Options
Tailing
Dam
Flotation
Roaster
Smelter
Low As
Conc
High As
Conc
Low As
Conc
Safe Disposal
e.g mine backfill
Ore
Arsenic Fumes
21. Green Processing 2006: 5-6 June 21
ConclusionsConclusions
Increasing pressure on metal producers to reduce emissions
and manage toxic elements deportment
Challenge - orebodies with higher levels of minor elements,
which are difficult to process
Early removal option offers competitive advantage
Several options for safe disposal of low volume highly toxic
streams, which could be linked with the early removal
We believe, it is time to put current capability into practice by
examining the integrated flowsheets to deal with the
management of the minor elements in a more sustainable
way.
22. Green Processing 2006: 5-6 June 22
AcknowledgementAcknowledgement
Some of the work and findings presented were generated
through a project carried out under the auspice and
financial support of the Cooperative Research Centre for
Sustainable Resource Processing, which was established
and is supported under the Australian Government's
Cooperative Research Centres Program
Editor's Notes
Each year Australia exports ~ 3 millions of tonnes of copper, nickel, lead and zinc in form of concentrate and refined metals.
Base metal ores contain low levels of toxic/hazardous elements e.g: As, Sb, Bi, Cd, Hg, Se, Te …, Th, U.
Clean, coarsely-grained ore bodies becoming depleted
Ore bodies of future becoming more complex, finer-grained and containing higher amount of minor/toxic elements.
Worldwide industry mines and process 100s million tpa of base metal ores
Accumulated mass of minor elements in biosphere is large and could have a significant environmental impact.
Removal and safe disposal of minor elements present technical and environmental problems as well as being costly
Smelters impose treatment charges and penalty payment on minor elements in concentrates, because of difficulties in their removal and safe disposal
Governments are becoming increasingly sensitive to emissions from smelters,
Pressure is building from the community for more sustainable processing
Smelter are setting tighter penalty specifications,
With increasing demand for base metals and increasing levels of minor elements in ores, there is an imperative to develop alternative treatments that allow removal of toxic elements at the mine site before despatch of concentrate to smelters
Primarily determined by mineralogy and grain size
Occurrence - association with other elements
Distribution between phases
If minor elements are widely and uniformly dispersed in mineral phases (as in a solid solution) treatment option is limited to separation and removal in waste or residue streams produced during smelting to recover valuable components
If toxic elements are concentrated in in discrete phases, options exists for early removal by physical and chemical means.
Physical means include separation based on differences in grain size or density, flotation characteristics, while chemical means include selective roasting or leaching
Having separated and concentrated the toxic elements, consideration has to be given to their use or safe disposal.
Is a good example of impurity element found in most base metal ores and concentrates
Lowers metal quality, if not removed from product metal
Contributes to health concerns during metallurgical processing
Causes environmental concerns during disposal of tailings and wastes
High arsenic levels in an ore can make the deposit economically unviable
Blending of high and low arsenic concentrates has been practiced by industry. Can we continue this in the future? Given the depleting clean and coarse-grained ore bodies, then the answer is NO.
We will use arsenic as an example to illustrate and compare the current processing options with alternative treatment options, namely early removal and safe disposal, that could offer a number of benefits.
In copper ores arsenic occurs as
Enargite (Cu3AsS4)Tennanite (3Cu2S.As2S3)
Arsenopyrite (FeAsS)Cobaltite (CoAsS)
In nickel systems
Gersdorffite (NiAsS)Niccolite (NiAs)
Arsenopyrite (FeAsS)Cobaltite (CoAsS)
Physical separation of As bearing minerals from non-arsenic bearing minerals is difficult
As they have similar specific gravity, non-magnetic, strongly floatable with conventional collectors etc.
Second important point is that some As minerals contain high concentration of copper and nickel e.g. enargite (Cu3AsS4) has 48% Cu
Recently, CSIRO has made advances in physical separation of arsenic-containing minerals from valuable minerals by floatation.
Given that the flotation behaviour of sulphide minerals depends on the oxidation-reduction state of pulp, then one can exploit this pulp potential effects to promote separation of arsenic-bearing sulphides such as enargite from non-arsenic sulphides.
A good example of applying this to separation of Enargite from Chalcopyrite is shown in this figure, where through controlling the pulp potential (between -25 and 50 mv at a pH of 8) selective flotation and separation of enargite should be possible.
Furthermore, according to the database developed at CSIRO, other copper-iron sulphide minerlas including birnite (Cu5FeS4) should be similar to that of Chalcopyrite.
Roasting has been used to remove arsenic from ores and concentrates
Elemental arsenic and its sulfides, chlorides and oxides are volatile at roasting temperatures and a number of treatment options have been developed and reviewed in literature.
Nakazawa, Yazawa and Jorgensen applied thermodynamics to simulate the removal of arsenic from copper concentrates in presence of oxygen
More recently Jorgensen and co-workers applied roasting technique to remove arsenic from nickel concentrate
Roasting has been used to remove arsenic from ores and concentrates
Elemental arsenic and its sulfides, chlorides and oxides are volatile at roasting temperatures and a number of treatment options have been developed and reviewed in literature.
Nakazawa, Yazawa and Jorgensen applied thermodynamics to simulate the removal of arsenic from copper concentrates in presence of oxygen
This figure shows some of the results from Nakazawa et al’s work on the effects of temperature and initial arsenic content on the degree of removal via roasting the concentrate with oxygen.
It is evident that the effect of temperature becomes more pronounced for low Arsenic containing concentrate, where vapour pressure of As bearing species is too low at lower temperatures for the set oxygen supply rate.
The effect of oxygen supply is shown in this figure, where maximum arsenic removal is achieved at Oxygen to chalcopyrite ratios between 2.5 and 3.5. At higher oxygen supply rate, oxidation of concentrate to non-volatile ferric arsenate occurs and results in sharp drop in the arsenic removal.
At higher temperature of 900 C, similar behaviour was predicted, but with some sudden dip in the extent of removal caused by the formation of non-volatile Cu3As as well as As2O3.
According to these results the ratio of 2.4 moles of oxygen per mole of chalcopyrite seems to be the optimum at 900 C.
This table compares results obtained from a number laboratory and plant scale practices. These results confirm the predictions by thermodynamic modelling i.e:
Low degree of arsenic removal at temperatures below 700 C and/or low initial arsenic content
Very high degree of arsenic removal from concentrates with &gt; 1% initial arsenic and at temperatures close to 700 C.
Recent work at CSIRO has shown high degree of arsenic removal from nickel concentrates.
We may thus conclude that selective roasting can convert the high arsenic-bearing concentrates into very low arsenic concentrate for smelters.
If toxic elements are dispersed at low levels through the valuable mineral component of concentrate, their removal is accomplished during smelting, converting and refining steps.
During smelting copper concentrate is reacted with air to oxidise and remove some of the sulphur and iron from the molten matte phase
CSIRO’s MPE package covers thermodynamic behaviour of several minor elements in slags, mattes, alloys and gas phases.
In this figure the predicted behaviour of As, Bi and Pb are shown during the smelting of copper concentrate to high grade mattes.
Arsenic and antimony report predominantly to gas phase
Bismuth and lead tends to concentrate in the gas phase while Selenium and tellurium report to the matte phase
The predicted behaviour have been shown to be in close agreement with laboratory data as well as plant data.
Calculations were carried out for converting of matte produced by smelting, using a 2-stage Pierce Smith converter, followed by fire-refining of the blister copper to produce anode copper.
For each stage of the flowsheet, the distribution of minor elements between condensed and gas phases was calculated.
The results for arsenic through these thermodynamic calculations are presented in this Figure.
It is evident that in the smelting step over 70% of the input arsenic reports to the gas phase with the remainder being distributed between the matte and slag.
The conversion of matte to blister copper results in further removal of the arsenic by the gas phase, but it is predominantly dispersed in the while metal and blister copper phase.
During the fire-refining very little of the remaining arsenic reports to the gas phase.
In this figure the overall deportment of arsenic between the phases is presented, where about 70% of the input arsenic is captured by the gas phase.
About 20% of the input arsenic reports to the slag phase and only 10% finds its way to the electro-refining.
Results for bismuth and lead show that these elements mostly report to the gas phase, with the residual concentration in the metal being extremely low.
On the other hand nearly all the Se and Te reported to the fire-refined anode copper.
While 70% of input arsenic and a portion of other toxic elements report to the gas streams, effective collection and safe disposal of these toxic elements is a significant issue, particularly when dirty concentrates are being treated.
Generally a portion of arsenic and other volatile species condense in the bag-houses with small portion reporting to the acid plant.
The portion that reports to acid plant is generally converted into gypsum and stored or disposed in tailing dams.
The condense fumes, which contain arsenic and other volatile elements, are sometimes recycled through the smelter for recovery of valuable components such as copper.
The production of arsenic and other toxic elements is well in excess of market demand
Typically these elements are produced by-products of smelting operations and are concentrated in form of fumes, dross, precipitates and slags
Consideration has to be given to the disposal of surplus in a safe and environmentally acceptable manner
This requires conversion to a less hazardous form and if the volume is small storage as a temporary solution
Longer term solutions are required
Arsenic trioxide is water soluble and requires conversion to more stable compounds before disposal
A number of options have been proposed in the past. These include; conversion into calcium arsenate, ferric arsenate or scorodite, encapsulation in concrete and locking the arsenic in silicate slags.
Each option has some merits and limitations. A careful assessment of these options is required.
The treatment options for managing the minor elements are determined b y their level and mineralogy in the primary flotation concentrate.
Low levels &lt;0.5% may be acceptable to a smelter without further treatment and subsequent processing involves conventional smelting and refining
However for higher levels additional processing may be required.
For cases where the arsenic is present as discrete grains and the gangue can be rejected to produce a clean concentrate then the flowsheet shown here could be considered. Here through combination of early removal by floatation and selective roasting of high arsenic portion the feed material to the smelter will be low arsenic concentrate.
If on the other hand the arsenic minerals are not amendable to differential floatation, it would be necessary to roast all the primary concentrate in order to produce a clean concentrate.
There is increasing community and government pressure on metal producers to reduce emissions and manage toxic elements deportment in an environmentally acceptable and sustainable way.
Metal producers are facing the challenge of orebodies with higher levels of minor elements, which are difficult to process
There is now an increased focus on minor element deportment in flowsheet development for base metals ores
The early removal option offers competitive advantage in respect to minor elements dispersion and management issues, as well as maintaining overall valuable metal recovery
There are several options for safe disposal of low volume highly toxic streams which could be generated with the early removal in processing
We believe it is time to put current capability into practice by examining the integrated flowsheets that deal with the management of the minor elements in a more sustainable way. This will involve, modelling, rigorous testing at laboratory and pilot scale followed by techno-economic evaluation and life cycle assessment.