Originally presented in Fayoum University Faculty of Engineering.
A quick presentation about chlor-alkali process which is used by the industry to produce chlorine gas , sodium hydroxide and hydrogen.
a report which contains more information about this topic can be downloaded from here:
https://goo.gl/8bQrnd
A topic of organotransition metal chemistry which is a part of course taught in university of Sargodha in BS chemistry 8th Smester in Inorganic Chemistry Minor
Environmental Technology for Cleaner ProductionSSA KPI
AACIMP 2010 Summer School lecture by Mårten Ericson. "Sustainable Development" stream. "Environmental Technology" course. Part 1.
More info at http://summerschool.ssa.org.ua
Originally presented in Fayoum University Faculty of Engineering.
A quick presentation about chlor-alkali process which is used by the industry to produce chlorine gas , sodium hydroxide and hydrogen.
a report which contains more information about this topic can be downloaded from here:
https://goo.gl/8bQrnd
A topic of organotransition metal chemistry which is a part of course taught in university of Sargodha in BS chemistry 8th Smester in Inorganic Chemistry Minor
Environmental Technology for Cleaner ProductionSSA KPI
AACIMP 2010 Summer School lecture by Mårten Ericson. "Sustainable Development" stream. "Environmental Technology" course. Part 1.
More info at http://summerschool.ssa.org.ua
This article is about salt chemical treatment and hot acid treatment of wells. In this case, research has covered different points of theoretical and methodological the hydrochloric acid treatment of the well. Finally, research has pinpointed on various views of outcomes and shortcomings at all. by Shukurov Abror Sharipovich 2020. Hydrochloric acid treatment of the well. International Journal on Integrated Education. 3, 9 (Sep. 2020), 77-79. DOI:https://doi.org/10.31149/ijie.v3i9.592. https://journals.researchparks.org/index.php/IJIE/article/view/592/566 https://journals.researchparks.org/index.php/IJIE/article/view/592
Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment St...Michael Hewitt, GISP
Jon Smoyer P.G., PA Department of Environmental Protection (DEP), “Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment Strategy”
Hydrogen Peroxide has been used to oxidize and remove ferrous iron from mine drainage for decades. It is a relatively inexpensive and effective oxidant that can be used to achieve rapid ferrous iron oxidation in many active and semi-passive mine drainage treatment systems. This presentation outlines the physical properties, concentrations, and available delivery options for hydrogen peroxide.
Extraction experiments for Zn(II) ions from aqueous phase by new laboratory prepared Azo
derivation as complex agent 2- [4-bromo-2,6-diethyl phenylazo] -4,5-diphenylimidazole(BDPI)shows the
optimum conditions for this extraction method was (pH= 8) (10 minutes) shaking time and 50μg
concentration of Zn(II)ions in aqueous phase. Organic solvents effect study shows there is not any linear
relation between distribution ratio (D) for extraction of Zn+2 ions and dielectric constant (ε)for organic
solvents used but there is in effect for organic solvent structure on the extraction of Zn+2 ions and
distribution ratio (D) values. Stoichiometric studies demonstrated the more probable structure ion pair
complex extracted for Zn+2 was 1:1.
Separation of calcium carbonate and barium sulphate from a mixed sludge prduc...Timothy Rukuni
South Africa is one of the first countries to implement full-scale mine water reclamation to drinking water quality. Reverse osmosis is already being used on full scale for desalination of mine water. However, with increased recycling of mine water, the result has been the increased generation of sludge. The Council for Scientific and Industrial Research (CSIR) has developed the Alkali-Barium-Carbonate (CSIR-ABC) process that can be used for neutralization and desalination of sulphate-rich effluents while recovering valuable by-products from the mixed sludges produced. A mixture of BaSO4 and CaCO3 sludge is produced as one of the by-products, which preferably needs to be separated into its components prior to thermal treatment. The aim of this study was to separate CaCO3 and BaSO4 from a CaCO3-BaSO4 mixed sludge through dissolution of CaCO3 as Ca(HCO3)2 in contact with CO2. Measured quantities of a simulated CaCO3-BaSO4 mixed sludge from the CSIR-ABC process were fed into a reactor vessel containing deionized water and pressurized CO2 was introduced. The effects of temperature and pressure with time were investigated while monitoring alkalinity, pH and calcium concentration. The findings of this study were: (1) The dissolution rate of CaCO3 was rapid i.e. from 0 to 2000mg/L in the first 20 minutes; (2) Ca(HCO3)2 had a high solubility of about 2 600 mg/L when in contact with CO2 at 1 atm., while BaSO4 was almost completely insoluble; (3) The solubility of Ca(HCO3)2 increased with decreasing temperature and increasing pressure; (4) CaCO3, after conversion to Ca(HCO3)2, was separated from BaSO4 in a CaCO3-BaSO4 mixed sludge; (5) Visual MINTEQ model is a powerful tool that can be used to predict the solubilities of CaCO3 and BaSO4 when contacted with CO2.
The manufacturing process of Hydrogen Peroxide. This slide will give u all information about the manufacturing process of hydrogen peroxide. First it will describe u about the raw material used for the manufacturing of hydrogen peroxide and then the manufacturing process of hydrogen peroxide and then the utilities and uses of hydrogen peroxide.
This work shows a method to prepare manganese
nanoparticles on carbon substrate and some inorganic and organic
salts such as carbonate, nitrate, chloride, citrate and acetate from
spent dry battery cells. The method involves dismantling the cell
followed by sulfuric acid leaching of the whole contents at
temperatures up to 75°C for 3 hours. The leaching products were
filtered and the metals went into solution were determined. Metals
other than manganese were chemically separated whereby
manganese hydroxide was precipitated at pH 8. Nanoparticles of
manganese were prepared by direct reduction of the hydroxide
using hydrazine hydrate. The hydroxide salt reacted with the
respective acid to prepare the required salt. Results revealed that
manganese content in the spent battery cell amounts to 22 % by
weight. Leaching extent in sulfuric acid increased with the
increasing the acid molarity up to 3, temperature of leaching up to
75 °C, leaching time up to 3 hours and stirring conditions. The
quality of the products have been characterized by XRD, SEM and
FT-IR investigations. The activation energy of the acid leaching of
manganese amounts to kJ.mol.
Presentation contain Waste-water treatment technologies for the removal of nitrogen and phosphorus. It includes Eutrophication, Nitrogen Removal by Nitrification and denitrification, Phosphorus Removal by Enhanced Biological Phosphorus Removal and by Chemical Treatment.
Recovery of Platinum and Rejuvenation of Alumina From Spent Reforming Catalys...Waqas Tariq
Abstract Recovery of platinum from spent naphtha reforming catalyst (Pt/γ-Al2O3) which contain 0.30 wt % of Pt was conducted using two methods, the first one was treatment of the spent catalyst with aqua regia whereas the second one involved chlorination of the spent catalyst. The results show that the chlorination method is more efficient than the acid treatment one as 93 % platinum can be recovered, in addition to reserving the γ-Al2O3 skeletal structure from serous changes. The recovered platinum was converted to hexachlorplatinic acid, a material that can be used to prepare the catalyst again by impregnation method using either new alumina or certain proportion of it and recovered one.
This article is about salt chemical treatment and hot acid treatment of wells. In this case, research has covered different points of theoretical and methodological the hydrochloric acid treatment of the well. Finally, research has pinpointed on various views of outcomes and shortcomings at all. by Shukurov Abror Sharipovich 2020. Hydrochloric acid treatment of the well. International Journal on Integrated Education. 3, 9 (Sep. 2020), 77-79. DOI:https://doi.org/10.31149/ijie.v3i9.592. https://journals.researchparks.org/index.php/IJIE/article/view/592/566 https://journals.researchparks.org/index.php/IJIE/article/view/592
Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment St...Michael Hewitt, GISP
Jon Smoyer P.G., PA Department of Environmental Protection (DEP), “Hydrogen Peroxide- Review of its Role as Part of a Mine Drainage Treatment Strategy”
Hydrogen Peroxide has been used to oxidize and remove ferrous iron from mine drainage for decades. It is a relatively inexpensive and effective oxidant that can be used to achieve rapid ferrous iron oxidation in many active and semi-passive mine drainage treatment systems. This presentation outlines the physical properties, concentrations, and available delivery options for hydrogen peroxide.
Extraction experiments for Zn(II) ions from aqueous phase by new laboratory prepared Azo
derivation as complex agent 2- [4-bromo-2,6-diethyl phenylazo] -4,5-diphenylimidazole(BDPI)shows the
optimum conditions for this extraction method was (pH= 8) (10 minutes) shaking time and 50μg
concentration of Zn(II)ions in aqueous phase. Organic solvents effect study shows there is not any linear
relation between distribution ratio (D) for extraction of Zn+2 ions and dielectric constant (ε)for organic
solvents used but there is in effect for organic solvent structure on the extraction of Zn+2 ions and
distribution ratio (D) values. Stoichiometric studies demonstrated the more probable structure ion pair
complex extracted for Zn+2 was 1:1.
Separation of calcium carbonate and barium sulphate from a mixed sludge prduc...Timothy Rukuni
South Africa is one of the first countries to implement full-scale mine water reclamation to drinking water quality. Reverse osmosis is already being used on full scale for desalination of mine water. However, with increased recycling of mine water, the result has been the increased generation of sludge. The Council for Scientific and Industrial Research (CSIR) has developed the Alkali-Barium-Carbonate (CSIR-ABC) process that can be used for neutralization and desalination of sulphate-rich effluents while recovering valuable by-products from the mixed sludges produced. A mixture of BaSO4 and CaCO3 sludge is produced as one of the by-products, which preferably needs to be separated into its components prior to thermal treatment. The aim of this study was to separate CaCO3 and BaSO4 from a CaCO3-BaSO4 mixed sludge through dissolution of CaCO3 as Ca(HCO3)2 in contact with CO2. Measured quantities of a simulated CaCO3-BaSO4 mixed sludge from the CSIR-ABC process were fed into a reactor vessel containing deionized water and pressurized CO2 was introduced. The effects of temperature and pressure with time were investigated while monitoring alkalinity, pH and calcium concentration. The findings of this study were: (1) The dissolution rate of CaCO3 was rapid i.e. from 0 to 2000mg/L in the first 20 minutes; (2) Ca(HCO3)2 had a high solubility of about 2 600 mg/L when in contact with CO2 at 1 atm., while BaSO4 was almost completely insoluble; (3) The solubility of Ca(HCO3)2 increased with decreasing temperature and increasing pressure; (4) CaCO3, after conversion to Ca(HCO3)2, was separated from BaSO4 in a CaCO3-BaSO4 mixed sludge; (5) Visual MINTEQ model is a powerful tool that can be used to predict the solubilities of CaCO3 and BaSO4 when contacted with CO2.
The manufacturing process of Hydrogen Peroxide. This slide will give u all information about the manufacturing process of hydrogen peroxide. First it will describe u about the raw material used for the manufacturing of hydrogen peroxide and then the manufacturing process of hydrogen peroxide and then the utilities and uses of hydrogen peroxide.
This work shows a method to prepare manganese
nanoparticles on carbon substrate and some inorganic and organic
salts such as carbonate, nitrate, chloride, citrate and acetate from
spent dry battery cells. The method involves dismantling the cell
followed by sulfuric acid leaching of the whole contents at
temperatures up to 75°C for 3 hours. The leaching products were
filtered and the metals went into solution were determined. Metals
other than manganese were chemically separated whereby
manganese hydroxide was precipitated at pH 8. Nanoparticles of
manganese were prepared by direct reduction of the hydroxide
using hydrazine hydrate. The hydroxide salt reacted with the
respective acid to prepare the required salt. Results revealed that
manganese content in the spent battery cell amounts to 22 % by
weight. Leaching extent in sulfuric acid increased with the
increasing the acid molarity up to 3, temperature of leaching up to
75 °C, leaching time up to 3 hours and stirring conditions. The
quality of the products have been characterized by XRD, SEM and
FT-IR investigations. The activation energy of the acid leaching of
manganese amounts to kJ.mol.
Presentation contain Waste-water treatment technologies for the removal of nitrogen and phosphorus. It includes Eutrophication, Nitrogen Removal by Nitrification and denitrification, Phosphorus Removal by Enhanced Biological Phosphorus Removal and by Chemical Treatment.
Recovery of Platinum and Rejuvenation of Alumina From Spent Reforming Catalys...Waqas Tariq
Abstract Recovery of platinum from spent naphtha reforming catalyst (Pt/γ-Al2O3) which contain 0.30 wt % of Pt was conducted using two methods, the first one was treatment of the spent catalyst with aqua regia whereas the second one involved chlorination of the spent catalyst. The results show that the chlorination method is more efficient than the acid treatment one as 93 % platinum can be recovered, in addition to reserving the γ-Al2O3 skeletal structure from serous changes. The recovered platinum was converted to hexachlorplatinic acid, a material that can be used to prepare the catalyst again by impregnation method using either new alumina or certain proportion of it and recovered one.
Информационно-поисковая система AskNet Search обеспечивает формирование точного ответа на вопрос пользователя, заданный на естественном языке.
AskNet – вопросно-ответная поисковая система, лидер тестирования РОМИП, (QA TREC). Ее интеллектуальность обусловлена комплексным лингвистическим анализом соответствия искомой информации заданному пользователем запросу на естественном языке. Поиск проводится в любой предварительно проиндексированной текстовой и мультимедийной информации. При этом на заданный пользователем вопрос на естественном языке система выдает предложения из проиндексированных текстов, которые по возможности наиболее точно отвечают на заданный вопрос. В результате этого достигнуто снижение «информационного шума» и значительное повышение соответствия ответа системы запросу пользователя. Поиск может проводиться с учетом синонимов и родственных слов, которые сгруппированы в соответствии с их семантическим значением.
Система позволяет автоматически найти или синтезировать смысловой ответ в предварительно проиндексированных текстах, содержащихся в электронных документах, мультимедийной информации, на страницах интернет сайтов или в поисковых системах Интернета. Демоверсия AskNet Search, реализующая только небольшую часть функций, размещена на сайте www.asknet.ru – прототип семантической поисковой системы.
Проектный офис РОСНАНО провел информационный семинар, посвященный вопросам взаимодействия с Фондом развития инновационного центра «Сколково» и условиям получения статуса резидента инновационного центра проектными компаниями.
Ruslan Kh.Khamizov, Natalya S.Vlasovskikh, Lilya P.Moroshkina, Sultan Kh.Khamizov
Scientific and Technological Company “NewChem Technology” LLC
SCIENTIFIC GROUNDS AND PROSPECTS FOR CLOSED–CIRCUIT PROCESSING OF ALUMINA-CONTAINING RAW MATERIALS WITH THE USE OF SALT-ACID METHOD
Neural network model for HCl recovery processpantapong
This paper describes neural network models (AI) for the prediction of the concentration profile of a hydrochloric acid recovery process consisting of double fixed-bed ion exchange columns.
Carbon-cuprous oxide composite nanoparticles
were chemically deposited on surface of thin glass tubes of spent
energy saving lamps for solar heat collection. Carbon was
obtained from fly ash of heavy oil incomplete combustion in
electric power stations. Impurities in the carbon were removed by
leaching with mineral acids. The mineral free-carbon was then
wet ground to have a submicron size. After filtration, it was
reacted with concentrated sulfuric/fuming nitric acid mixture on
cold for 3-4 days. Potassium chlorate was then added drop wise on
hot conditions to a carbon slurry followed by filtration.
Nanocarbon sample was mixed with 5% by weight PVA to help
adhesion to the glass surface. Carbon so deposited was doped with
copper nitrate solution. After dryness, the carbon/copper nitrate
film was dipped in hydrazine hydrate to form cuprous oxide -
carbon composite, It was then roasted at 380-400 °C A heat
collector testing assembly was constructed of 5 glass coils
connected in series with a total surface area of 1250 cm2
. Heat
collection was estimated by water flowing in the glass coils that
are coated with the carbon/copper film,. Parameters affecting the
solar collection efficiency such as time of exposure and mass flow
rate of the water were studied. Results revealed that the prepared
glass coil has proven successful energy collector for solar heat.
Utilization of milk of lime (MOL) originated from carbide lime waste and oper...Patrick Okoye
High purity (>99%) precipitated calcium carbonate, PCC was synthesized from abundant waste material (carbide sludge), generated during acetylene gas production. The reaction influencing parameters based on temperature, flow rate, total dissolved solid and carbide lime concentration were investigated.
REVIEW PAPER ON BAUXITE RESIDUE CHARACTERISTICS, DISPOSAL &UTILIZATIONijiert bestjournal
Worldwide bauxite residue disposal areas contain an estimated 2.7 billion tonnes of residue,
increasing by approximately 120 million tonnes per annum. Presently, it is stored on land or in
ocean near alumina refineries. However, its high alkalinity is a potential pollution to water; land
and air of close proximity .meanwhile high cost are associated with a large area of land needed
for storage of residue. In this paper focuses on process of waste generation, its characteristics,
conventional disposal method & bauxite residue utilization in building material glass ceramics,
concrete, bricks, phosphate removal etc.
A revolutionary new hydro-metallurgical technology has been developed by two companies; Doe Run Company, USA in partnership with M/s Engitec, Italy. A commercial plant for producing 60,000 tonnes per annum of lead metal at an estimated capital cost of 150 million US Dollar is envisaged setting up by Doe Run Company, St. Louis, Missouri, USA. The breakthrough technology not only envisages improvements in lead processing efficiencies but also is expected to drastically reduce air emissions, waste generations and water pollution and will have smaller carbon footprint.
Prills /granular urea are not only costly for the
producer but may be harmful to humans and the
environment. Furthermore, nano Urea may also
be used for enhancing abiotic stress tolerance.
Nano-Urea prevents environmental pollution and
improves physiological traits of wheat grown
under drought stress conditions. The nano urea
consist of higher surface area because lesser in
size of the nano particle and have high
reactivity, solubility in water. Nano Urea are the
important tools in agriculture to improve crop
efficiency, yield and quality parameters with
increase nutrient use efficiency, reduce wastage
of fertilizers and cost of cultivation. Nano-urea
is very effective for precise nutrient management
in precision agriculture with matching the crop
growth stage for nutrient and may provide
nutrient throughout the crop growth period.
Nano-Urea increase crop growth up to optimum
concentrations further increase in concentration
may inhibit the crop growth due to the toxicity
of nutrient. Nano-Urea provide more surface
area for different metabolic reactions in the plant
which increase rate of photosynthesis and
produce more dry matter and yield of the crop. It
is also prevent plant from different biotic and
abiotic stress.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
1. 1
Scientific grounds and prospects for closed–circuit processing of alumina-containing raw materials with the use of salt-acid method
R. Kh. Khamizov1, N.S. Vlasovskikh2, L.P. Moroshkina3, S. Kh. Khamizov4
1. Research manager of the NewChem Technology", LLC, Moscow, Russia,
2. Department head, NewChem Technology", LLC, Moscow, Russia
3. Technologist, NewChem Technology", LLC, Moscow, Russia
4. General director of the NewChem Technology", LLC, Moscow, Russia
Corresponding author: khamiz@mail.ru
Abstract
A brief overview and critical analysis of acid and acid-salt methods for processing alumina raw materials, including high-silica bauxite, nepheline and clay is presented. The basic approaches to the creation of closed and reagent-less or low-reagent-consumption processes are demonstrated. The results obtained in the course of long-term systematic laboratory and bench studies carried out in the “NewChem Technology” Company are presented, and they display the prospects for the creation of new technologies for the production of alumina from high silica bauxite and aluminum silicates with the use of different nitrate and sulfate reagents. In the case of using acids, the method of "acid retardation" in nano-porous media is shown to be successfully used for recycling them into the process head and to ensure soft conditions for the removal of iron components. A circular process with the recovery and consumption of the same amount of salt reagent in each cycle is demonstrated. A comparison of digestion methods is given in terms of the completeness of reagent recycling, the quality of product and the complexity of the process. Advisable conditions for the production of alumina from non- traditional raw with salt-acid decomposition are shown.
Key words: high-silica bauxite, nepheline, digestion, salt method, NewChem method.
1. Introduction
Standard industrial alkaline methods for alumina production (Bayer process and its modifications) require low-silica raw materials which become inaccessible due to the gradual depletion of high-grade bauxite deposits. Using the Bayer process and its analogues for treatment of low-quality bauxites and alumina-silicate materials, such as nepheline, is not advisable from the technological and economic reasons. This is related to many factors including the fact that in the technological process, silica reacts with the alkali, binding a large amount of it, as well as alumina, forming the mixed compound – hydro-alumino-silicates and so leading to their losses [1]. Sintering processes adjoin to the alkaline ones and they consist in sintering raw materials with limestone or limestone and soda or caustic followed by washing final cakes with water or aqueous soda solution. Currently, about 40% of alumina produced in Russia is obtained from the nepheline of Kola and syenite deposits of Siberia by this method [2]. However, significant limitations of these methods are in high energy consumption and in the need for processing and utilization of large quantities of by-soda-lime-silica products. In the future, at increase in energy prices, the effectiveness of the sintering method can be reduced.
Acid methods, the use of which allows separating the silica already at the first stages of the process without additional inputs of its binding reagents, can become alternative to alkali refining methods [3]. Analysis of the available research results conducted for many decades in Russia, Germany, China and other countries shows major weaknesses of acid technologies. Among them, one can note four major drawbacks:
a) difficulties arise in the creation of closed reagent-free or low-reagent-intake processes.
2. 2
b) as a rule, these processes are characterized by high energy consumption;
c) supplementary processing and additional steps are needed for iron removal;
d) typically, hard-filterable mixes are formed at acid decomposition.
The first and second of these items are related to the fact that thermo-hydrolysis of compounds containing acid residues and aluminum (as well as iron) is the main approach to “save” and recycle acids in technological circuits. Usually for inorganic salts, thermo-hydrolysis itself requires high energy. As to the reactant loosing, special difficulties arise at using nitric or sulfuric acid. High-temperature treatment of nitrates or sulfates leads to the emission of nitrogen or sulfur–containing gases, mainly, SO2 or NO2. To save the acids for technological recirculation, these oxides should be chemically transformed into according acids, and this is expensive. Fewer problems arise when using hydrochloric acid [4]. Perhaps, this is the reason why some companies involved in promising developments, in particular, the Orbit Aluminae Co., apply a well-known process of the thermo-hydrolysis of AlCl3 [5]. Finally, there is one serious (but little discussed) problem associated with the irreversible losses of reagents in acid technologies. To achieve high speed and good degree of digestion and leaching, it is necessary to use the excesses of acids relative to equivalent amounts of feed components reacting with them. Until recently, it was not known advisable methods for the recovery of these acid excesses to return them into the technological cycle.
Salt methods provide good opportunities for the creation of closed-circular processes. Among them, two best reactants for digestion should be noted: ammonium bi-fluoride (NH4HF2) and ammonium hydro-sulfate (NH4HSO4). For example, a method [6] is known for processing of alumino-silicates, in particular clay materials, by refluxing them in a solution of ammonium bi- fluoride to obtain a precipitate containing aluminum hydroxide and aluminum fluoride, which is separated, dried and decomposed by steam at to obtain an aluminum hydroxide and recycle of hydrogen fluoride. However, the method has several drawbacks, including the fact that a substantial portion of the original NH4HF2 is spent; besides it, there are serious hardware requirements which must be stable in the vapor of hydrofluoric acid.
Ammonium hydro-sulfate (bisulfate) process was invented by Max Buchner in Hanover- Kleefeld in 1921, piloted in Germany in the 1920s and in Oregon in 1944. Now this method is included in the list of named processes in chemical technology and is called “Aloton” or “Buchner” [7,8]. The technique consists in implementing circular process comprising the steps of thermal decomposition of ammonium sulfate into ammonia and ammonium bisulfate, dissolving the latter to treat the aluminum-containing feedstock in an autoclave, filtration of solution of alum and precipitating aluminum hydroxide with ammonia, isolation of ammonium sulfate from the mother liquor to return it to the head of circuit. Subsequently, embodiments of the Buchner method appear under which the digestion stage is carried out not by the “wet” process, but by the way of sintering the ammonium sulfate with the raw material [9-11] The process was not commercialized, and it can be assumed that in those days, in the case of good access to high quality raw bauxite materials the Buchner process could not withstand competition with the Bayer one. Moreover, it turned out that the method is suitable for processing readily degradable clay materials and other alumino-silicates, but is poorly applicable to Bauxites [12].
Today, in the new circumstances, it seems appropriate to return to the Buchner process for analyzing its weaknesses and assessing the prospects. This article is devoted to an attempt to solve this problem (yet, at the laboratory level) by combining the capabilities of acid and salt methods and by introducing a previously unknown process stage, called by us “NewChem”, which greatly facilitates the creation of real closed-circular schemes for processing high-silica bauxites and alumino-silicate materials.
3. 3
2. Experimental
Three types of alumina-containing raw materials from different deposits of Russia were used: Timan bauxite of hematite-boehmite type; Kaichak kaolin clay and Kola nepheline concentrate. Table 1 shows the contents of macro-components in these materials (bauxite and kaolin work samples, as well as the analytical data on their composition, have been presented by the “Rusal –Vami” Company, S.-Petersburg, Russia; nepheline concentrate has been presented by the NIUIF Institute of the FOSAGRO Co., Moscow, Russia)
Table 1. Chemical composition of raw materials (mass %)
Al2O3
Fe2O3
SiO2
TiO2
K2O
MgO
Na2O
P2O5
SO3
CaO
SrO
MnO
H2O
Bauxite
47.7
28.3
8.0
2.8
0.63
0.39
0.23
0.22
0.20
0.17
-
0.04
11.5
Kaolin clay
18.3
2.7
64.2
1.7
2.0
0.89
2.1
0.15
-
0.87
-
1.0
7.0
Nepheline
28.0
2.4
44.0
0.55
7.6
0.45
12.5
0.17
-
1.75
0.11
0.08
1.5
A granulated strong-base anion exchanger, AV-17x8, with quaternary ammonium functional groups and with polystyrene gel type matrix with pores 20-50 nm was used for the elaboration of nano-porous reactor. Acid retardation experiments were carried out with special plastic column containing granulated material and filled with organic liquid immiscible with water and water solutions. One of systems used is shown in Figure 1.A. For the exclusion of ion–exchange processes, anionic resin in nitrate form was used in nitrate media and in sulfate forms – in sulfate ones. Technical-grade reactants including nitric and sulfuric acid, ammonium sulfate, ammonium sulfite and calcium hydroxide were used for the implementation of different stages of processing. Lab-ware glass, autoclave system for 200 bar and vacuum filtering system with removable filtering cloth and disposable filtering papers were also used.
3. Results and discussion 3.1. Acid Retardation and NewChem approach
Let us introduce a proposed separation technique first for acid technology and then transfer it to salt-acid method. To insulate the acid residues from the concentrated media, for example, from mixed solutions of salts of various metals, for the recovery of those acids and recycling them in the head technological process, it is necessary to have a suitable separation method. The principle of such a method was discovered in the early 1960s [1], and it concerned the possibility of separating acids from their salts in highly concentrated solutions on anion- exchangers a ion form similar to the common anion of separated components. The method, called Acid Retardation by its authors, was not based on ion exchange. Today, we know, that anionic resins of gel type can be used owing to their nano-sized pores. In concentrated solutions, acids form ion pairs or slightly hydrated molecules that have small sizes and can penetrate into the nano-porous media. At the same time, salts are well dissociated under these conditions to form highly hydrated cations and anions, which meet steric hindrances. Therefore, by passing the dissolved mixture of salts and acid through the column bed, the acid is retained in the bed, and salt thereof, substantially without altering their concentration in the solution, is skipped through the column. The process is cyclic one. In each cycle, the feed solution is passed through the system, which may be called “nano-porous reactor”, until the breakthrough, then, almost pure acid is washed by ordinary water and the process is repeated. The method proved to be attractive due to the fact that no reactant is required, just water is used. For a long time, this method did not find industrial application due to difficulties in organizing the flow distribution in columns to eliminate mixing of the different substances. Since the late 1970s, after process
4. 4
modifications, it began to be applied and is now widely used, for example, by the Eco-Tec Company (Canada) [2,3]. For optimization of the flow distribution in EcoTec columns, they are over-packed, and the interspace between grains is reduced by pressure. Unfortunately, this technology is not applicable to suspensions, turbid work liquors, as well as to supersaturated solutions and colloidal systems.
A B
Fig. 1. NewChem system for separation of acids and salts. A. Photograph of a column (nano-porous reactor) with organic phase. B. Sectional diagram of the column loading
Our approach consists in reducing the space occupied by water and working solutions in the columns by using an additional liquid phase [13]. The column, loaded with anionic resin or other nano-porous material, is additionally filled by an organic liquid immiscible with the aqueous solutions. No special facilities and no high pressures are required and the ion exchange materials can be used for long time. All the column processes can be carried out in down-flow mode for both salt passing and acid desorption stages of the working cycle. The following interpretation of mass transfer mechanisms in the proposed system can be given. On passing ion containing solutions through a bed of granular ion exchange material in the absence of free space between the grains, as well as under conditions where the organic liquid repels water or the aqueous solution, the latter, being introduced at the interface between the organic liquid and the hydrophilic surface of the granules, forms very thin films enveloping each ion exchange bead and drains by the points of contact between them (Figure 1.B). Such a steady state dynamic system of ultra-thin mobile films provides extremely well developed surface area of contact between the phases taking part in the mass exchange process. Owing to the fact that working solutions occupy negligible space volume in the column, there is no possibility of the flows of different substances mixing, and also no problems arise with the choice of direction of these flows. In the case of colloidal systems, they can be freely passed through the column bed, no conditions for growing solid particles and forming large-sized crystals take place. The organic liquid always remains inside the column, but once, a very small volume can be removed on start-up of the column. For hydrodynamic reasons, such a loss can also take place on operation with too high flow rates. However, the lighter organic liquid on leaving the column seeks immediately to go up and can be returned to the column by a tube connecting bottom and
5. 5
top. Such a system is shown in Figure 1. We called the proposed method, “NewChem” from the name of the company which played an important role in its development [13,14].
Consider the effect of using the NewChem method for practical processing of the nepheline concentrate by treatment of the mixed solution produced by nitric acid leaching. Composition of the influent to be processed was (mass %): H2O- 67; Al(NO3)3 - 16; HNO3 -7.3; NaNO3 - 5.9; KNO3- 2.1; Fe(NO3)3-1.2. The problem here is the need to separate acid to return it to the head of the process, thus leading to significant savings in acid.
Fig. 2. Break-through concentration curves of HNO3 (1, 1`) and dissolved Al (2) in one of the repetitive separation cycles of the acid process. 3 – concentration of Fe in effluent samples before the precipitation of iron hydroxide . Laboratory column loadings: 90 ml of granulated strong base anionic resin AV-17 of gel type in NO3-form. Organic phase - decanol. Flow rate: 2 BV h-1.
Figure 2 shows concentration histories for the separation of nitric acid and aluminium nitrate on the nitrate form of the anionic resin. At a sorption stage, the actual liquid concentrate produced by acid leaching of nepheline concentrate was used as the feed solution; acid desorption stage was performed by deionized water. Effluent volumes corresponding to these different stages are separated by vertical solid straight line in the figure. The dashed vertical lines indicate the left and right bounds within which the effluent fractions are to be returned into separating reactor.
There are more interesting properties of the process shown in Fig.2: a) owing to deep separation at acid retardation, the effluent is to be neutral or weakly acidic (pH>2 up to 130 ml). It leads to the formation of colloidal solution at passing through the bed and to spontaneous precipitation of iron hydroxide within 1 – 1.5 hours after column leaving; b) checking the balance of separated acid shows its amount exceeding the content of the free acid in raw solution. It takes place owing to the effect of ‘soft hydrolysis” which can take place, as follows:
3[R-NO3…H2O] + Fe(NO3)3 = Fe(OH)3↓ + 3[R-NO3…HNO3] ( 1 )
3[R-NO3…HNO3] + 3H2O = 3[R-NO3…H2O] + 3HNO3 ( 2 )
6. 6
where: R denotes the resin group which can be associated with water or acid molecule. Process (1) takes place at sorption stage and (2) – at acid desorption.
Thus, at using acidic digestion technology, the NewChem method allows: returning the residual acid in the process; carrying out additional purification of work solution from iron; carrying out (partially) low-energy consuming process of soft hydrolysis (instead of thermo-hydrolysis) and additional returning the corresponding amount of acid in the process.
3.2. Analysis of the Buchner process and salt-acid method
Let us consider the possibilities of modifying the salt Buchner process to optimize it by the use of NewChem method and other advisable adding to improve. First, we have to state that in both (acid and salt) process types, the mechanism of digestion consists in chemical reaction with acid. Below, this is illustrated by the balance of selected components in a cyclic process:
Al2O3 + 6NH4HSO4 ( 3(NH4)2SO4 + 3H2SO4 ) = 2NH4Al(SO4)2 + 3H2O + 2(NH4)2SO4 ( 3 ) 2NH4Al(SO4)2 + 6NH3 + 6H2O = 2Al(OH)3↓ + 4(NH4)2SO4 ( 4 ) 6(NH4)2SO4 = 6NH4HSO4 + 6NH3↑ ( 5 )
In such an ideal pattern, pictured by the reactions (3) – (5), the Buchner process can be fulfilled as the closed-circuit one. Practically, this is hard to be reached at a sacrifice of spending acid for the formation of sulfates of some impurities (Ca, Na, K). It is illustrated by the equation (6) for the interaction of ammonium hydro-sulfate with bauxite in an actual process (numerical coefficients reflect the molar ratios of components). Not so much impurities exist in bauxite materials, but the problem can be more serious for different alumino-silicates.
0.57Al2O3.0.23Fe2O3.(0.12SiO2.0.05TiO2.0.01MgO.0.01K2O.0.005Na2O.0.005CaO) + 4.8 NH4HSO4 + 17.13H2O + 0.03H2SO4 = 1.14AlNH4(SO4)2.12H2O + 0.46 FeNH4(SO4)2.12H2O + 1.6 (NH4)2SO4 + 0.12H2SiO3 + 0.05TiO2.2H2O + 0.01MgSO4.7H2O + 0.01K2SO4.H2O + 0.005Na2SO4.10H2O + 0.005CaSO4.2H2O ( 6 )
Additionally to this problem, it is important to take into consideration that at acid mechanism of digestion, it is advisable to keep some excess of acid in the technological circuit to achieve good kinetics and the extraction degree. Finally, the addition of acid salt reagent and use of salt-acid method leads to the better solution of silica problem.
Table 2. The degree of leaching for various alumina sources at the use of ammonium bisulfate and it with small addition of sulfuric acid. (S/L = 1:10, digestion time - 3 hours)
Temperature, 0C
Nepheline
40% solution of NH4HSO4
Nepheline
40% NH4HSO4 + 1% H2SO4
Kaolin
40% solution of NH4HSO4
Bauxite
40% solution of NH4HSO4
Bauxite
40% NH4HSO4 + 1% H2SO4
85
48
66
52
18
55
90
72
95
59
44
58
98
85
99
59
48
60
120
98
98
65
60
81
150
92
100
80
62
86
175
96
99
87
65
89
7. 7
In a series of experiments, the capabilities of the Buchner salt method were tested for various raw materials, and salt-acid method was compared to it on opening the bauxite of hematite- boehmite type at equal conditions. For temperatures up to 950C the experiments were carried out with open reactors, at more temperatures – with autoclave. The results obtained are shown in Table 2. They demonstrate the advantages of using minor addition of acid into the salt reagent, especially, at comparison of bauxite digestion with Buchner method and with salt-acid reagent. Similar effect on aluminium leaching degree takes place for the nepheline concentrate. Taking into account that the concentration of acid is too low in the last one, it is advisable to suggest that the visible effect has not thermodynamic, but the kinetic character.
Figure 3 shows the schematic diagram which we proposed and used for salt acid processing of different raw materials. For the simplicity of the diagram not all the stages can be drawn. After the stage of preliminary separation of iron, hot liquor was treated with small amount of ammonium sulfite for reducing F(III) to Fe (II), then it was cooled for the crystallization of alum. As it is pictured, the NewChem reactor was used for mother solution after the alum separation.
Fig.3. Flow diagram for salt-acid circular process
8. 8
Some distinction takes in the case of acid separation accompanied by the purification from Fe(II). The process of spontaneous precipitation of iron hydroxide is relatively slow, and
aeration is required for the speedup of the process. The results of the NewChem treatment are shown in Fig.4. The view of concentration curves is similar to that for the acid process described above.
Fig. 4. Break-through concentration curves of H2SO4 (1, 1`) and dissolved Al (2) in one of the technological cycles. 3 – concentration of Fe in effluent before the precipitation. Pilot column loadings: anionic resin AV-17 of gel type in SO4 -form. Organic phase - decanol.
Experimental tests and balance estimations show the feasibility of fully closed cyclic process in the main reagent - sulfate (bisulfate) ammonium. For the production of 1 kg of the metallurgical alumina in the repetitive technological cycles, the following data on expenses can be given as an example: 2.63 kg of bauxite; 100 g of technical grade (94%) sulfuric acid; 30 g of ammonium sulfite; 40 g of calcium hydroxide; 1.2 l of softened water, 7.5 kg of steam.
4. Conclusions
Salt-acid method was proposed, experimentally tested and the closed-circuit process for high- silica bauxite and alumino-silicates was demonstrated.
The NewChem method was introduced and its advantages were shown. They include returning the residual acid in the process; carrying out additional purification of work solution from iron; carrying out low-energy consuming process of soft hydrolysis and additional returning the corresponding amount of acid in the process.
5. References
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2. Isakov, E.A., Pikalevskaya association alumina in new condition, Tsvetnye Metally (Non- Ferrous Metals), No. 4, (1997), pp 8-9 (in Russian).
9. 9
3. Matveev, V.A., Physico-chemical and technological bases to improve the efficiency of complex processing of raw nepheline by acid methods, Theses Diss. Dr. Sciences, Apatity, 2009 (in Russian).
4. Weissenbaeck ,H., Nowak, B., Vogl, D., Krenn, H., Development of Chloride Based Metal Extraction Techniques - Advancements and Setbacks, Nickel-Cobalt-Copper Conference of ALTA-2013, 29 May – 1 June, 2013, pp 360-362, pub ed. Perth, W.A., Melbourne, Australia, 2013.
5. Patent of Russian Federation 2471010 (2008) / Budro, A., Rishar ,S., Biazotto, F., Method for extraction of aluminum and iron from alumina-containing ores.
6. US Patent 1.426.891, (1922) / McClenahan, F.M., Process of recovering metals from silicates.
7. U.S. Patent 1.493.320 (1924)/ Buchner, M., Process for manufacturing aluminum hydroxide (British Patent 195,998, Russian patent 11489).
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9. Ullmann, B., Encyklopadie der technischen Chemie, Auflage, Urban & Schwarzenberg, Miinchen & Berlin (1954) Bd. 3, pp 401-420.
10. Grim, R.E., Applied Clay Mineralogy,. McGraw-Hill, New York (1962) pp 335-345
11. Bayer, G., Kahr, G., and Mueller-Vonmoos, M., Reactions of ammonium sulphates with kaolinite and other silicate and oxide minerals, Clay Minerals, Vol.17, (1982), pp 271-283.
12. O’Connor, D. J., Alumina Extraction from Non-bauxitic Materials, Aluminium-Verlag, Düsseldorf (1988), p.159.
13. Hatch MJ and Dillon JA, Acid retardation. A simple physical method of separation of strong acids from their salts. I&EC Process Design and Development. 2/4: 253-263 (1963)
14. Brown CJ, Fluid treatment method and apparatus, US Patent No 4673507, June 16, (1987)
15. Sheedy M, Recoflo ion exchange technology. Proceedings of the TMS Annual Meeting held in 1998 in San Antonio Texas (1998)
16. Patent of Russian Federation 2434679 (2011)/ Khamizov, R.Kh., Krachak, A.,N, Podgornaya, E.K., Khamizov, S.Kh., The method for carrying out sorption mass-exchange processes, apparatus for its implementation, industrial plant for separation of the components of inorganic water solutions and apparatus for the insulation of organic liquids from water solutions.
17. Khamizov, R.Kh., Krachak, A.N., Khamizov, S.Kh., Separation of ionic mixtures in columns with two liquid phases, Sorption and Chromatographic Processes, Vol.14, No1, (2014), pp 14-23