Ceramic materials are inorganic, non-metallic materials made from compounds of a metal and a non metal. Ceramic materials may be crystalline or partly crystalline.
The word ceramic comes from the Greek word keramiko of pottery" or for pottery from keramos.
Ceramics and Glass Technology (Silicate Glasses, Boric Oxide and Borate Glass...Ajjay Kumar Gupta
Ceramics and Glass Technology (Silicate Glasses, Boric Oxide and Borate Glasses, Phosphorus Pentoxide and Phosphate Glasses, Germanium Dioxide and Germanate Glasses, Nitrate Glasses, Halide Glasses, Chalcogenide Glasses, Modern Glass Working, Monax and Pyrex Glass)
Glass-ceramics are mostly produced in two steps: First, a glass is formed by a glass-manufacturing process. The glass is cooled down and is then reheated in a second step. In this heat treatment the glass partly crystallizes. In most cases nucleation agents are added to the base composition of the glass-ceramic. These nucleation agents aid and control the crystallization process.
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applications of Ceramics, Boric Oxide and Borate Glasses, Business guidance for glass ceramics, Business Plan for a Startup Business, Business start-up, Ceramic and glass business, ceramic business ideas, Ceramic forming techniques, Ceramic Industry, Ceramic Material Manufacturing Methods, Ceramic processing, Ceramics and Glass Technology, Ceramics Based Profitable Projects, Ceramics Based Small Scale Industries Projects, ceramics business plan, Ceramics Forming Processes, Ceramics pottery Manufacturing, Ceramics Processing Projects, Ceramics Production Industry in India, Chalcogenide Glasses, Germanium Dioxide and Germanate Glasses, Glass & ceramics Business, Glass & ceramics Small Business Manufacturing, Glass and Ceramics, glass and ceramics industry, Glass and Ceramics Technology, Glass Based Profitable Projects, Glass Based Small Scale Industries Projects, Glass Ceramic Products, Glass Ceramics Industry, glass ceramics properties, Glass Forming & Processing, glass forming process, Glass Forming Technology, Glass making - Industry process, Glass Manufacture and Processing, Glass Manufacturing Process, Glass Processing Projects, Glass production, Glass Production Industry in India, Glass-ceramic materials, Glass-ceramics: their production, properties and potential, Great Opportunity for Startup, Halide Glasses, How to Start a Ceramic Business, How to Start a Ceramics Production Business, How to start a glass & ceramics business?, How to Start a Glass Production Business, How to start a successful glass ceramics business, How to Start Ceramics Production Industry in India, How to Start Glass Production Industry in India, Modern Glass Working, Modern Small and Cottage Scale Industries, Monax and Pyrex Glass, Most Profitable Ceramics manufacturing Business Ideas, Most Profitable Glass manufacturing Business Ideas, New small scale ideas in Ceramics Production industry, New small scale ideas in Glass Production industry, Nitrate Glasses, Phosphorus Pentoxide and Phosphate Glasses, Processing Glass and Glass-Ceramics, Production of Glass Ceramic, Profitable Small and Cottage Scale Industries
Ceramic materials are inorganic, non-metallic materials made from compounds of a metal and a non metal. Ceramic materials may be crystalline or partly crystalline.
The word ceramic comes from the Greek word keramiko of pottery" or for pottery from keramos.
Ceramics and Glass Technology (Silicate Glasses, Boric Oxide and Borate Glass...Ajjay Kumar Gupta
Ceramics and Glass Technology (Silicate Glasses, Boric Oxide and Borate Glasses, Phosphorus Pentoxide and Phosphate Glasses, Germanium Dioxide and Germanate Glasses, Nitrate Glasses, Halide Glasses, Chalcogenide Glasses, Modern Glass Working, Monax and Pyrex Glass)
Glass-ceramics are mostly produced in two steps: First, a glass is formed by a glass-manufacturing process. The glass is cooled down and is then reheated in a second step. In this heat treatment the glass partly crystallizes. In most cases nucleation agents are added to the base composition of the glass-ceramic. These nucleation agents aid and control the crystallization process.
See more
http://goo.gl/o2fHY4
http://goo.gl/45cRC2
http://goo.gl/PWr5dE
Email:
npcs.ei@gmail.com
info@entrepreneurindia.co
Tags
applications of Ceramics, Boric Oxide and Borate Glasses, Business guidance for glass ceramics, Business Plan for a Startup Business, Business start-up, Ceramic and glass business, ceramic business ideas, Ceramic forming techniques, Ceramic Industry, Ceramic Material Manufacturing Methods, Ceramic processing, Ceramics and Glass Technology, Ceramics Based Profitable Projects, Ceramics Based Small Scale Industries Projects, ceramics business plan, Ceramics Forming Processes, Ceramics pottery Manufacturing, Ceramics Processing Projects, Ceramics Production Industry in India, Chalcogenide Glasses, Germanium Dioxide and Germanate Glasses, Glass & ceramics Business, Glass & ceramics Small Business Manufacturing, Glass and Ceramics, glass and ceramics industry, Glass and Ceramics Technology, Glass Based Profitable Projects, Glass Based Small Scale Industries Projects, Glass Ceramic Products, Glass Ceramics Industry, glass ceramics properties, Glass Forming & Processing, glass forming process, Glass Forming Technology, Glass making - Industry process, Glass Manufacture and Processing, Glass Manufacturing Process, Glass Processing Projects, Glass production, Glass Production Industry in India, Glass-ceramic materials, Glass-ceramics: their production, properties and potential, Great Opportunity for Startup, Halide Glasses, How to Start a Ceramic Business, How to Start a Ceramics Production Business, How to start a glass & ceramics business?, How to Start a Glass Production Business, How to start a successful glass ceramics business, How to Start Ceramics Production Industry in India, How to Start Glass Production Industry in India, Modern Glass Working, Modern Small and Cottage Scale Industries, Monax and Pyrex Glass, Most Profitable Ceramics manufacturing Business Ideas, Most Profitable Glass manufacturing Business Ideas, New small scale ideas in Ceramics Production industry, New small scale ideas in Glass Production industry, Nitrate Glasses, Phosphorus Pentoxide and Phosphate Glasses, Processing Glass and Glass-Ceramics, Production of Glass Ceramic, Profitable Small and Cottage Scale Industries
Glass is an inorganic product of fusion that has cooled to a rigid condition without crystallizing. Glass is typically hard and brittle, and has a conchoidal fracture. A glass may be colorless or colored. It is usually transparent, but may be made translucent or opaque (such as in white, opal glass). Objects made of glass are loosely and popularly referred to as glass; such as glass for a tumbler, a barometer, a window, a magnifier, or a mirror. The subject of studying glass in materials science is an important part.
Ceramics are important engineering materials from engineering applications point of view.This presentation gives briefly important properties and applications of ceramics
introduction of ceramic: A ceramic is an inorganic, nonmetallic solid material comprising metal, nonmetal or metalloid atoms primarily held in ionic and all are made by firing or burning, often including silicates and metal oxides.
classification and types of ceramic, application of ceramic and innovations on it.
This presentation is all about Glass, its properties,the raw materials used in glass, the manufacturing process for making glasses and then different types of glasses and their properties. :)
Glass is an inorganic product of fusion that has cooled to a rigid condition without crystallizing. Glass is typically hard and brittle, and has a conchoidal fracture. A glass may be colorless or colored. It is usually transparent, but may be made translucent or opaque (such as in white, opal glass). Objects made of glass are loosely and popularly referred to as glass; such as glass for a tumbler, a barometer, a window, a magnifier, or a mirror. The subject of studying glass in materials science is an important part.
Ceramics are important engineering materials from engineering applications point of view.This presentation gives briefly important properties and applications of ceramics
introduction of ceramic: A ceramic is an inorganic, nonmetallic solid material comprising metal, nonmetal or metalloid atoms primarily held in ionic and all are made by firing or burning, often including silicates and metal oxides.
classification and types of ceramic, application of ceramic and innovations on it.
This presentation is all about Glass, its properties,the raw materials used in glass, the manufacturing process for making glasses and then different types of glasses and their properties. :)
Glass Industry (Chemistry of Glass industry) Pakistan's Glass IndustryMuhammad Abubakar
This Presention is about the chemistry of glass industry.
This includes
Glass
Types of glass
General properties of glass
Manufacturing process of glass
Uses of glass.
Pakistan's glass's economy
import and export of float glass of Pakistan
The ppt is useful for basic information on Cement, glass & refactories.
All above materials are used as Civil engineering materials.
Study group: Polytechnic level, For First Year students.
Engineering Materials:
Portland Cement: Definition, manufacturing by Rotary Kiln, role of gypsum, chemistry of
setting and hardening of cement.
Glass: Definition, manufacturing by tank furnace, significance of annealing, types and
properties of soft glass, hard glass, borosilicate glass.
Lubricants: Classification, mechanism, properties; viscosity and viscosity index, flash and
fire point, cloud and pour point.
i have made all the slide for civil engineering and poly diploma civil.
these are 100% correct but in case of some error comment down or contact me on (laxmans227@gmail.com)
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software - power point presentation 2015
This ppt is made for the f****ng teachers who give there students these foolish work and waste there time....hope..next time the'll nt give these type of HOLIDAY.H.W..
The objectives of this course in iron ore Resources and iron industry are:
i) acquainting students (majors and non-majors) with the basic tools necessary for studying iron ore deposits and processes,
ii) different processes for phosphorus removal from iron ore
iii) beneficiation processes of iron ore deposits.
iv) different processes and techniques that used to enrichment low-grade iron ore resources
v) understanding the different ironwork processes and technology,
vi) understanding the different types of iron ore products,
vii) prominent routes for steelmaking
viii) understanding the relationship between the distribution of iron ore and scrap, as well as steelmarkets,
ix) steel industry in Egypt , and
x) gaining some knowledge of the global iron ore as well as environmental problems associated with the extraction and utilization of iron ore resources.
There are plenty of hard-to-beneficiate iron ores and high-grade tailings in India and all over the world; As the volume of high-grade iron ores declines.
Minerals phase transformation by hydrogen reduction (MPTH) can efficiently revitalize hard-to-beneficiate iron ore resources and tailings, turning the waste into profitable products. It may also improve the concentrate quality comparing to that from the previous method. From the economic and environmental aspects, MPTH is the most effective method to recover iron oxides.
The clean minerals phase transformation by hydrogen reduction (MPTH) was proposed.
Industrial utilization of limonite/goethite, limonite-hematite, sulfur-bearing refractory iron ore was achieved, where Sulfur-bearing minerals decomposed or formed sulfate after oxidation roasting.
Sulfur content of iron ore concentrate was significantly reduced to 0.038 %.
Improving utilization efficiency of refractory iron ore resources is a common theme for the sustainable development of the world’s steel and iron industry.
Magnetization Roasting is considered as an effective and typical method for the beneficiation of refractory iron ores.
After magnetization roasting, the weakly magnetic iron minerals, including hematite, limonite and siderite, are selectively reduced or oxidized to ferromagnetic magnetite, which is relatively easier to enrich by Magnetic Separation after liberation pretreatments.
The Primary Magnetization Roasting Methods include: Shaft Furnace Roasting, Rotary Kiln Roasting, Fluidized Bed Roasting, and Microwave assisted roasting. The developments in magnetization roasting of difficult to treat iron ores, including: Shaft Furnace Roasting, Rotary Kiln Roasting, Fluidized Bed Roasting, and Microwave Assisted Roasting in the Past Decade.
Shaft Furnace Roasting is gradually eliminated due to its high energy consumption and low industrial processing capacity, and the primary problem for rotary kiln roasting is the kiln coating which affects the yield of iron resource and its industrial application.
Fluidized Bed Roasting and Microwave assisted roasting are considered as the most effective and promising methods.
Suspension (Fluidized) Magnetization Roasting is recognized as the most effective and promising technology due to its high reaction efficiency, low energy consumption and large processing capacity. Moreover, an industrial production line with a throughput of 1.65 million t/a for beneficiation of a specularite ore has been built.
Microwave Assisted Roasting is a potential alternative technology for magnetizing iron ores. However, it is currently limited to laboratory research and has no industrial application. Forwarding microwave assisted magnetization roasting methods into industrial applications needs long way and time to achieve.
Furthermore, using biomass, H2 or siderite as a reducing agent in the magnetic reduction roasting of iron ores is a beneficial way to reduce carbon emissions, which can be called clean and green magnetization roasting technology.
In the future, technical research on clean and green magnetization roasting should be strengthened. Maybe microwave magnetization roasting using biomass/H2/siderite as reductant can be further studied for a more effective and greener magnetization of iron ores.
WORLD RESOURCES IRON DEPOSITS
Iron Ore Pellets Market Industry Trends
Scope and Market Size
Market Analysis and Insights
DRI Production in Plants Using Merchant Iron Ore
Outlook for DR grade pellet supply‐demand out to 2030
DRI and the pathway to carbon‐neutral steelmaking
Supply‐side challenges for the steel & iron ore industries
scrap is the main raw material, is growing in the structure of global steelmaking capacities; SCARP/ RECYCLING IRON ; EAF steel production method in the world; Scrap for Stock; A Global Scrap Shortage;Availability of Ferrous Scrap Resources; EGYPT IRON SCRAP IMPORTS.
The iron ore production has significantly expanded in recent years, owing to increasing steel demands in developing countries.
However, the content of iron in ore deposits has deteriorated and low-grade iron ore has been processed.
The fine ores resulting from the concentration process must be agglomerated for use in iron and steelmaking.
Bentonite is the most used binder due to favorable mechanical and metallurgical pellet properties, but it contains impurities especially silica and alumina.
Better quality wet, dry, preheated, and fired pellets can be produced with combined binders, such as organic and inorganic salts, when compared with bentonite-bonded pellets.
While organic binders provide sufficient wet and dry pellet strengths, inorganic salts provide the required preheated and fired pellet strengths.
The industrial development program of any country, by and large, is based on its natural resources.
Currently the majority of the world’s steel is produced through either one of the two main routes: i) the integrated Blast Furnace – Basic Oxygen Furnace (BF – BOF) route or ii) the Direct Reduced Iron - Electric Arc Furnace (DRI - EAF) route.
Depleting resources of coking coal, the world over, is posing a threat to the conventional (Blast Furnace [Bf]–Basic Oxygen Furnace [BOF]) route of iron and steelmaking.
During the last four decades, a new route of ironmaking has rapidly developed for Direct Reduction (DR) of iron ore to metallic iron by using noncoking coal/natural gas.
This product is known as Direct Reduced Iron (DRI) or Sponge Iron.
Processes that produce iron by reduction of iron ore (in solid state) below the melting point are generally classified as DR processes.
Based on the types of reductant used, DR processes can be broadly classified into two groups: (1) coal-based DR process and (2) gas-based DR process.
Details of DR processes, reoxidation, storage, transportation, and application of DRI are discussed in this presentation.
This presentation reviews the different DR processes used to produce Direct Reduced Iron (DRI), providing an analysis on the quality requirements of iron-bearing ores for use in these processes. The presentation also discusses the environmental sustainability of such processes. DR processes reduce iron ore in its solid state by the use of either natural gas or coal as reducing agents, and they have a comparative advantage of low capital costs, low emissions and production flexibility over the BF process.
Currently the majority of the world’s steel is produced through either one of the two main routes: i) the integrated Blast Furnace – Basic Oxygen Furnace (BF – BOF) route or ii) the Direct Reduced Iron - Electric Arc Furnace (DRI - EAF) route.
In the former, the blast furnace uses iron ore, scrap metal, coke and pulverized coal as raw materials to produce hot metal for conversion in the BOF. Although it is still the prevalent process, blast furnace hot metal production has declined over the years due to diminishing quality of metallurgical coke, low supply of scrap metal and environmental problems associated with the process. These factors have contributed to the development of alternative technologies of ironmaking, of which Direct Reduction (DR) processes are expected to emerge as preferred alternatives in the future.
This presentation reviews the different DR processes used to produce Direct Reduced Iron (DRI), providing an analysis on the quality requirements of iron-bearing ores for use in these processes. The presentation also discusses the environmental sustainability of such processes. DR processes reduce iron ore in its solid state by the use of either natural gas or coal as reducing agents, and they have a comparative advantage of low capital costs, low emissions and production flexibility over the BF process.
Ironmaking represents the first step in steelmaking.
The iron and steel industry is the most energy-intensive and capital-intensive manufacturing sector in the world (Strezov, 2006).
Steelmaking processes depend on different forms of iron as primary feed material. Traditionally, the main sources of iron for making steel were Blast Furnace hot metal and recycled steel in the form of scrap.
The Blast Furnace (BF) has remained the workhorse of worldwide virgin iron production (i.e., hot metal) for more than 200 years. Over the years, BFs have evolved into highly efficient chemical reactors, capable of providing stable operation with a wide range of feed materials.
However, operation of modern efficient BFs normally involves sintering and coke making and their associated environmental problems.
More than 90% of iron is currently produced via the BF process, while the rest is coming from Direct Reduction (DR) processes, Mini Blast Furnaces (MBFs), Corex, Finex, Ausmelt, etc. Additionally, the severe shortage of good-quality metallurgical coal has remained an additional constraint all over the world. In view of this, there is an increasing awareness that the BF route needs to be supplemented with alternative ironmaking processes that are more environment friendly and less dependent on metallurgical coal.
Because of the rapid depletion of easily processed iron ores, the utilization of refractory ores has attracted increasing attention .
There several billion tonnes iron deposits, and most are refractory ores, which are difficult to process by conventional methods because of the low iron grade, fine grain size and complex mineralogy.
The beneficiation of low-grade iron ores to meet the growing demand for iron and steel is an important research topic.
At present, magnetization roasting followed by magnetic separation is one of the most effective technologies for the beneficiation of refractory iron ores.
However, certain ores do not qualify to be treated in physical separation processes, and hence, alternative strategies are being looked into for upgrading their iron content.
Reduction roasting has many advantages over the physical beneficiation process, such as enhanced iron recovery and processing of complex and poorly liberated iron ores.
The objective of this presentation is to compile and amalgamate the crucial information regarding the beneficiation of low-grade iron ores using carbothermic reduction followed by magnetic separation, which is a promising technique to treat iron ores with complex mineralogy and liberation issues.
Reduction roasting studies done for different types low-grade iron ores including oolitic iron ores, banded iron ores, iron ore slimes and tailings, and industrial wastes have been discussed.
Reduction roasting followed by magnetic separation is a promising method to recover the iron values from low-grade iron ores.
The process involves the reduction of the goethite and hematite phases to magnetite, which can subsequently be recovered using a low-intensity magnetic separation unit.
The large-scale technological advancements in reduction roasting and the possibilities of the application of alternative reductants as substitutes for coal have also been highlighted.
This presentation aims at insight light on the occurrence of phosphorus in iron ores from the mines around the world.
The presentation extends to the phosphorus removal processes of this mineral to meet the specifications of the steel industry.
Phosphorus is a contaminant that can be hard to remove, especially when one does not know its mode of occurrence in the ores.
Phosphorus can be removed from iron ore by very different routes of treatment. The genesis of the reserve, the mineralogy, the cost and sustainability define the technology to be applied.
The presentations surveyed cite removal by physical processes (flotation and selective agglomeration), chemical (leaching), thermal and bioleaching processes.
Removal results of above 90% and less than 0.05% residual phosphorus are noticed, which is the maximum value required in most of the products generated in the processing of iron ore.
Chinese studies show that the direct reduction roasting of high phosphorus oolitic hematite followed by magnetic separation is reality technical solutions to improve the recovery of metallic iron and dephosphorization rate.
For ores with widespread phosphorus in the iron matrix and low release, thermal or mixed processes are closer to reality technical solutions. Due to their higher operating costs, it will be necessary to rethink the processes of sintering and pelletizing, such that these operations also become phosphorus removal steps.
With the exhaustive processing of the known reserves of hematite from Iron Ore Quadrangle (Minas Gerais-Brazil), there will be no shortage of granules in the not too distant future. THEREFORE, THERE IS AN EXPECTATION THAT THE ORE MINED WILL HAVE HIGHER LEVELS OF PHOSPHORUS.
Overview of IRON TYPES: Pig Iron, Direct Reduced Iron (DRI), Hot Briquetted Iron (HBI), Cold Briquetted Iron (CBI) and Cold Briquetted Iron and Carbon (CBIC) Specifications .
Comparison of Pig Iron and DRI
Properties; Manufacturing Process; Uses; Largest producers and markets
Iron ore mining plays a critical role in supplying the raw material necessary for steel production, supporting various industries and economic development worldwide.
From the extraction of iron ore to its processing and eventual export, each stage of the mining process requires careful planning, technological advancements, and environmental considerations.
By adopting sustainable mining practices and mitigating environmental impacts, the future of iron ore mining can be aligned with the principles of responsible resource utilization and environmental stewardship
The Egyptian steel sector is the second largest steel market in the Middle East and North Africa region in terms of production and third largest in terms of consumption.
Egypt was the third-ranked producer of Direct-Reduced Iron (DRI) in the Middle east and North Africa region after Iran and Saudi Arabia and accounted for 5.4% of the world’s total output
The Egyptian steel industry represents one of the cornerstones of Egypt’s economic growth and development, due to its linkages to almost all other industries that stimulate economic expansion, such as construction, housing, infrastructure, consumer goods and automotive. All these industries rely heavily on steel industry and so, the importance and development of the steel sector is significant for the progress of the Egyptian economy in general.
The Egyptian market has many companies that produce different steel products.
Geological consultant, working in a range of roles from project development/feasibility study programs and advanced exploration roles. Contracts in a variety of global locations including Egypt, Saudi Arab, and the Middle East. Commodities including Gold, base metal sulfide, Gossan/Supergene, heavy mineral sands, clay/kaolin, Silica Sand, and iron ore.
Exploration in Deep Weathering Profiles, Supergene, R-mode factor analysis; Multi-element association geochemistry; Assessment of Au-Zn potentiality in Gossan; Rodruin-Egypt
Mineral Processing: Crusher and Crushing; Secondary and Tertiary Crushing Circuits; Types of Crusher; Types of Crushing; Types of Jaw Crushers; Impact Crusher; Types of Cone Crushers; Ball Mill; BEST STONE MANUFACTURERS; Local Quality and High quality ; International and Country/Hand made
Classification Equipment
Introduction; Chemical composition of garnet; Structure; Classification; Physical properties; Optical properties; Occurrences; Gem variety; and Uses
Garnet group of minerals is one of the important group of minerals.
Since they are found in wide variety of colours, they are also used as gemstones.
Garnet group of minerals are also abrasives and thus have various industrial applications.
Richard's aventures in two entangled wonderlandsRichard 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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
2. OUTLINE OF TOPIC 4:
Glasses
Raw Materials:
a) Silica sand
b) Limestone
c) Impurity
Glass Manufacturing Process
Glass Forming
Glass Structure
Glass Properties
Glass Types:
i) Soda-lime glasses
ii) Lead glasses
iii) Heat-resistant or borosilicate glasses
iv) High-purity silica glasses
v) Specialty glasses
Heat Treating Glasses:
a) Annealing glass
b) Tempered glass
Chemistry of Glass Manufacture
Recycling of Glass
Virtification
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 2
3. Question
What is Glass?
A glass can be defined as an inorganic product which has cooled to rigid structure without
crystallization.
A state of matter as well as a type of ceramic.
As a state of matter, the term refers to an amorphous (noncrystalline) structure of a
solid material.
The glassy state occurs in a material when insufficient time is allowed during
cooling from the molten state for the crystalline structure to form.
As a type of ceramic, glass is an inorganic, nonmetallic compound (or mixture of
compounds) that cools to a rigid condition without crystallizing.
Glass ceramics have an amorphous phase and one or more crystalline
phases and are produced by a so called "controlled crystallization" in
contrast to a spontaneous crystallization
Glass-ceramics are mostly produced in two steps:
First, a glass is formed by a glass manufacturing process.
The glass is cooled down and is then reheated in a second step. In this
heat treatment the glass partly crystallizes
Two prime characteristics of glass are their optical transparency and the
relative ease with which they may be fabricated.
21 November 2015 Prof. Dr. H.Z. Harraz Presentation Glass 3
5. Glasses
A glass can be defined as an inorganic product which has cooled to rigid structure without crystallization.
Glass is hard material normally fragile and transparent common in our life.
Glass-ceramics have an amorphous phase and one or more crystalline phases and are produced by a so
called "controlled crystallization" in contrast to a spontaneous crystallization
Glass-ceramics are mostly produced in two steps:
First, a glass is formed by a glass manufacturing process.
The glass is cooled down and is then reheated in a second step. In this heat treatment the glass
partly crystallizes
Two prime characteristics of glass are their optical transparency and the relative ease with which they may
be fabricated.
Amorphous Ceramics (Glasses) Main ingredient is Silica (SiO2)
If cooled very slowly will form crystalline structure.
If cooled more quickly will form amorphous structure consisting of
disordered and linked chains of Silicon and Oxygen atoms.
This accounts for its transparency as it is the crystal boundaries that
scatter the light, causing reflection.
Glass can be tempered to increase its toughness and resistance to
cracking.
6. RAW MATERIALS
Raw Materials Approximate
Proportion (wt %)
Provides Approximate Proportion
in glass (wt %)
Soda ash (NaHCO3) 25 Soda (Na2O) 18
Limestone (CaCO3) 10 Lime (CaO) 7
Silica sand (SiO2) 65 Silica (SiO2) 75
Raw materials used in lime-soda glass
a) Silica sand
Silica sand suitable for glass manufacture is however relatively
rare, because of the need for a high degree of chemical purity.
The essential requirements for silica sand for glass manufacture
are that it must be even grain size - more than 90% of grains must
lie in the range 125-500µm, and its chemical composition must
meet the requirements shown in Table 4.
Maximum
Cr2O3
Maximum
Fe2O3
Minimum
SiO2Glass
0.000150.01399.7Opthalmic glass
0.00020.01099.6Tableware, crystal and borosilicate glass
0.00050.03098.8Colourless containers
--0.2597.0Coloured containers
0.00010.1099.0Clear flat glass
Table 4: Required chemical composition of silica sand for glass manufacture
Fig.1: High pure silica sand raw
materials
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 6
7. a) Silica sand
The discolouring impurities iron and chromium occur within the non-quartz mineral fraction of the
sands.
Iron can occur as haematite, giving the sand a red colour, or as oxy-hydroxidcs (giving a yellow or brown
colour) as well as in silicate minerals.
Chromium occurs as the heavy mineral chromite (FeCr2O4), which is stable during glass manufacture,
and so rather than resulting in a discoloured glass, it persists as solid inclusions within the finished
product, which can cause it to be brittle. This is especially important for float glass manufacture, where
persistence of chromite grains can render useless substantial lengths of glass strip. Because of the
difficulties involved in the chemical determination of minor amounts of Cr it may be appropriate simply
to count the number of grains of chromite detected optically within a sample of known weight in order
to classify a sand as suitable for float-glass.
Alumina is a natural impurity in glass sands, arising from the presence of feldspars, mica or clay
minerals, and varies from 0.4% to 1.2% Al2O3 High values in this compositional range are preferred
because they help to reduce melting temperatures (yet another component is added) and involve no
negative effect on glass colour or other physical properties. The occurrence of aluminium as an
impurity may also be beneficial by reducing the need to add aluminosilicates (feldspar, aplite or
nepheline syenite) for the manufacture of certain glasses.
Great care is taken to consider the minor components of a glass, as small traces of impurities may have
a major positive or negative effect on the quality of the finished product. For example, the presence of
traces of iron may give a pale green colour (often visible when examining a pane of glass end on), and
this can be tolerated in some applications (such as container glass).
Other minor components might have beneficial effects on the qualities of the glass produced. For
example, addition of lithium (reduces the temperature required to melt the glass, and so yields savings
in energy costs.
21 November 2015 Prof. Dr. H.Z. Harraz Presentation Glass 7
8. b) Limestone
• Limestone is required twice in glass manufacture - once to produce
sodium carbonate and secondly as an ingredient in the batch to be
melted.
• As an ingredient in batches to be melted to produce glass, limestone
purity is critical. In particular, Fe contents have to be very low, and the
amount of MgO, as in dolomite, has to be known. In some glasses MgO is
added using pure dolomite, but the amounts have to be controlled.
• Like CaO, MgO causes immiscibility in glass melts; the miscibility gap in the
system SiO2-MgO is wider than that in the system SiO2-CaO (Fig.4).
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 8
9. Impurity
The Na2O and CaO decrease the softening point of this glass from 1600oC to 730oC
So that soda lime glass is easier to form.
An addition of 1 – 4% MgO is added to Soda lime glass to prevent cracks.
Magnesium can be substituted for a proportion of the calcium content by the use of
dolomite instead of limestone
In addition of 0.5 – 1.5% Al2O3 is used to Increase the durability. Alumina is a
widespread component of glasses in addition to soda ash and silica, and helps
improve resistance to weathering.
Boric oxide (to produce heat-resistant glasses such as 'Pyrex' and 'Vycor') and
Lead oxide (for lead crystal tableware).
Potassium can be substituted for some of the sodium with the use of feldspar, aplite
or nepheline syenite.
fluorides.: used to produce Opaque glasses .
Lithium (Li2O) is added to the glass composition: The amounts required are very
small, frequently ~1 to <4%. Lithium is added to glasses for several reasons, because
it reduces liquidus temperatures; it improves moulding properties (reduces
viscosity); it improves thermal properties ('Pyrex', ceramic hobs) and it improves
strength.
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 9
10. Glass Manufacturing Process
1. Silica sand, limestone, soda ash and cullet (recycled glass or
broken glass) are keep dry and cool in a batcher house in
silos or compartments
2. Mixing and weighting into proper proportion:
Sand (SiO2), Quartz, or Silica sand
72%
Flux → to lower T – e.g. Soda or
Soda Ash (NaHCO3) 17%; (1700 –
900oC)
Stabilizing agent → to mitigate
water solubility of the glass
formed – e.g. CaO normally added
as Limestone {Lime 5%}
www.glassforever.co.uk/howisglassmade/
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 10
11. Why So Much SiO2 in Glass?
• Because SiO2 is the best glass former :
Silica is the main component in glass products, usually comprising 50% to 75% of total chemistry.
It naturally transforms into a glassy state upon cooling from the liquid, whereas most ceramics
crystallize upon solidification.
Other Ingredients in Glass
• Sodium oxide (Na2O), calcium oxide (CaO), aluminum oxide (Al2O3),
magnesium oxide (MgO), potassium oxide (K2O), lead oxide (PbO), and boron
oxide (B2O3)
• Functions:
Act as flux (promoting fusion) during heating
Increase fluidity in molten glass for processing
Improve chemical resistance against attack by acids, basic
substances, or water
Add color to the glass
Alter index of refraction for optical applications
21 November 2015Prof. Dr. H.Z. Harraz Presentation Glass11
12. Glass Manufacturing Process (Cont. )
3. Send to furnaces in hoppers:
operated by natural gas
heat the mixture at 1300-1600oC into soften or molten state
4. Molding (or Casting ): molten glass flows to forming machine to
mold into desire shapes
5. Annealing lehrs : reheating the glass in an oven
to ensure even cooling of glass for strengthening of the
products
6. Cooling process: Cool for 30 min to an hour for safe to handle.
7. Glass products are then decorated, inspected again and finally
packaged and shipped to our customers. Glass Furnace Cooling Systems
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 12
Process
13. Glass Forming
Flat glass – floating / rolling
Glass fibre – continuous strands and Crown
process for glass wool
1) Casting : molding
2) Pressing: pressing second mold into molten glass
3) Core-forming: clay core dipped into molten mass
4) Fusing : fusing glass rods together around a mold
5) Blowing: blowing air into a glob
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 13
14. Glass Fabrication Methods
• Pressing:
GLASS
FORMING
Adapted from Fig. 13.8, Callister, 7e. (Fig. 13.8 is adapted from C.J. Phillips, Glass: The
Miracle Maker, Pittman Publishing Ltd., London.)
Gob
Parison
mold
Pressing
operation
• Blowing:
suspended
Parison
Finishing
mold
Compressed
air
plates, dishes, cheap glasses
-mold is steel with graphite
lining
• Fiber drawing:
wind up
PARTICULATE
FORMING
CEMENTATION
16. Float Glass: The Process
Image from Prof. JS Colton, Ga. Institute of Technology
Modern Plate/Sheet Glass making:
17. Glass Structure
• Quartz is crystalline
SiO2:
• Basic Unit: • Glass is amorphous
• Amorphous structure
occurs by adding impurities
(Na+,Mg2+,Ca2+, Al3+)
• Impurities:
interfere with formation of crystalline
structure.
(soda glass)
Adapted from Fig. 12.11, Callister, 7e.
SiO 4 tetrahedron
4-
Si 4+
O2-
Si 4+
Na +
O2-
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 17
18. Glass Properties
Specific volume (1/r) vs Temperature (T):
• Glasses:
do not crystallize
change in slope in spec. vol. curve at
glass transition temperature, Tg
-- transparent
- no crystals to scatter light
Crystalline materials:
crystallize at melting temp, Tm
have abrupt change in spec. vol. at
Tm
Adapted from Fig. 13.6, Callister, 7e.
T
Specific volume
Supercooled
Liquid
solid
T m
Liquid
(disordered)
Crystalline
(i.e., ordered)
T g
Glass
(amorphous solid)
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 18
19. Glass Types
Five common types of glass:
i) Soda-lime glasses
ii) Lead glasses
iii) Borosilicate or Heat-resistant glasses
iv) High-purity Silica glasses
v) Speciality glasses
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 19
20. i) Soda-Lime-Silica Glasses
• 65% sand; 15% soda; 10% lime
• In this glass component are:
71 – 73% SiO2
12 – 14% Na2O
10 – 12% CaO
• Adding sodium oxide (soda) lowers melting point
• Adding calcium oxide (lime) makes it insoluble
• Sodium and calcium ions terminate the network and soften
the glass
• The Na2O & CaO decrease the softening point of this glass from
1600oC to 730oC, So that soda lime glass is easier to form.
• An addition of 1 – 4% MgO is added to Soda lime glass to prevent
cracks.
• In addition of 0.5 – 1.5% Al2O3 is used to Increase the durability
• Soda-lime-silica glass is most commonly produced glass which
accounts for ~95% of all the glass produced in the world.
• Soda-lime-silica glass expands much when heated
Breaks easily during heating or cooling
Uses
Soda lime glass is used for flat glass, containers, lightening
products.
It is used where chemical durability and heat resistant are
not needed
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 20
21. ii) Lead Glasses
• Lime and soda replaced with lead oxide (PbO)
• Contains lead oxide (PbO) to improve refractive index
• High refractive index- clarity sparkle
• Softer –cut and engrave
• Good electrical resistance - electronics
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 21
22. iii) Heat-resistant (or Borosilicate) Glasses
• Contains Boron oxide, known as
Pyrex.
• Boron-oxide-silica glass expands
less
Tolerates heating or cooling
reasonably well
• Pyrex and Kimax are borosilicate
glasses
• Boron oxide replaces lime and
most of soda – low thermal
expansion coefficient
• Al2O3 - B2O3 – aluminosilicate glass
with even better heat resistance
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 22
23. iv) High-purity Silica Glasses
• Highest quality – most durable
• 3 processes – melting pure SiO2; making 96% silica and flame
hydrolysis
• Pure SiO2 – pure silica melted @ 1900 ºC under vacuum
• 96% - Vycor process – borosilicate glass heated to
grow crystalline sodium borate channels –
extracted hot HNO3 – leaving 96% pure silica after
heat reduction @ 1200 ºC
• flame hydrolysis – SiCl4 in CH4 / O flame (1500ºC,
produces high-surface silica soot thermally
sintered to pure silica at 1723 ºC)
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 23
2H2O + SiCl4 SiO2 + 4HCl
Flame
24. v) Specialty Glasses
• Coloured glass:
MnO2 – violet,
CoO – blue,
Cr2O3 - green
• Opal glass:
white opaque or translucent glassware
colour due to scattering of light from small particle
usually NaF/CaF crystals
nucleating after a cooling and reheating process
• Frosted glass:
satiny look when exposed to HF
OHSiFSiOHF 242 24
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 24
25. v) Speciality (Cont.)
• Coated glass:
unique properties
metal / metal oxides Ag+ + RA Ag mirror
electrically conducting with SnO2 coating (thermal SnCl4
hydrolysis)
• Photosensitive glass:–
glass that changes colour upon exposure to light
Phototropic:
darkens upon exposure to light and returns to original clear
sate afterwards.
AgCl/AgBr
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 25
Ag+ X- Ag + X
light
dark Blue-greycolorless
Non-silicate glasses are becoming increasingly important for special optical
purposes,
for example in the use of glasses prepared from CaF2, AlF3 and P2O5
for infrared optics or the use of fluoride glasses for optical fibres
26. Heat Treating Glass
Annealing:
removes internal stress caused by uneven cooling.
Tempering:
puts surface of glass part into compression
suppresses growth of cracks from surface scratches.
sequence:
further cooled
tension
compression
compression
before cooling
hot
surface cooling
hot
cooler
cooler
Result: surface crack growth is suppressed.
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 26
27. a) Annealing Glass
Annealing is a process of slowly cooling glass to relieve internal
stresses after it was formed.
The process may be carried out in a temperature-controlled kiln
known as a Lehr.
Annealing glass is critical to its durability.
Removes internal stress caused by uneven cooling.
Glass which has not been annealed is liable to crack or shatter
when subjected to a relatively small temperature change or
mechanical shock.
If glass is not annealed, it will retain many of the thermal stresses
caused by quenching and significantly decrease the overall
strength of the glass.
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 27
28. b) Tempered Glass
• The tempering process consists of the following steps:
1) First the glass is washed and then heated.
2) In order to temper glass, it must reach 1100°F (the softening point for glass.)
3) The glass is then cooled with cold air. Quenching with forced cold air sets up the tension and compression
zones.
4) The tempered glass continues down the rollers to cool more and be packed for shipping. Glass to be tempered
must be cut to size before the tempering step.
• A flow chart in the next slide provides a summary of the tempering process.
Tempered Glass: The Process
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 28
29. b) Tempered Glass (Cont.)
• Tempering glass:
Heat glass to softening point
Cool outside of glass quickly
Outside stiffens while inside is still
hot
Shrinking inside compresses
outside
Compressed outside stretches
inside
• Resists fractures because surface is
compressed
• Crumbles when cracked because inside
is tense
Glass expands when heated
Quenching “freezes” this expansion on the
outside
Center cools more slowly, and contracts. Sets up
tension and compression zones.
Tempered Glass is required for door products and
some windows installed near doors. If tempering
is done improperly then distortion can result.
Tempered glass is stronger than annealed glass.
If annealed glass (raw float) has a strength factor
of “1”, tempered glass would be “4”.
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 29
30. What is the difference between (regular) annealed glass and tempered glass?
Annealed (regular) Glass
• Advantages:
Cost
• Limitations:
Breaks in sharp pieces
Not as strong as
Tempered Glass
Size limitations
Tempered Glass
• Advantages:
4 times the stronger than
annealed
Breaks into small, harmless
pieces.
Qualifies as Safety Glazing
• Limitations:
Must be cut to size before
tempering
Optical distortion (roller wave,
strain pattern)
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 30
31. Examples of today’s glass products:
Containers (jars and bottles)
Flat glass (windows, vehicle
glazing, mirrors, etc.)
Lighting glass (fluorescent
tubes, light bulbs, etc.)
Tableware (drinking glasses,
bowls, lead crystal, etc.)
Laboratory equipments (test
tubes, cylinders, measuring
flasks, etc.)
TV tubes and screens
Decorative glass
Fiberglass
Optical glass
Vacuum flasks
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 31
32. CHEMISTRY OF GLASS MANUFACTURE
In general terms, soda-lime-silica glass manufacture involves melting the required
raw material mix at 1600°C, which yields a very fluid melt, from which gases can
escape (especially carbon dioxide produced by the decomposition of carbonate raw
materials).
The glass is then worked to produce the articles required at about 1000°C, followed
by annealing at 500-600°C.
Example; the float glass process, used to produce flat panes of glass suitable for
windows, illustrates this well (Fig.3).
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 32
Fig.3: Diagram of the float glass process, showing the way a continuous ribbon of glass is drawn from the melting furnace, through
the float bath (which gives the perfect surface to the sheet) and then is annealed and allowed to cool before preparation for sale.
33. CHEMISTRY OF GLASS MANUFACTURE (Cont.)
A glass is little more than a rapidly quenched liquid
The term 'Glass' can be applied to many different materials, but in common
usage it refers to quenched silicate liquids, , which behaves as a solid but
retains the molecular structure of the liquid.
The production of commercial glasses is therefore dictated by the
application of phase diagrams which allow the melting behaviour of
particular compositions to be predicted and the optimum conditions for
glass manufacture to be identified.
The appropriate phase diagram is that for the system SiO2-CaO-Na2O (Fig.4).
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 33
34. CHEMISTRY OF GLASS MANUFACTURE (Cont.)
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 34
Fig 4: Phase relation ships for part of the system SiO2-CaO-Na2O at atmospheric pressure (weight%).
The system includes the following crystalline phases:
Name Formula Abbreviated formula
Cristobalite SiO
2
S
Tridymite SiO
2
S
Quartz SiO
2
S
Pseudowollastonite CaSiO
3
CS
Sodium silicate NaSiO
3
NS
Sodium disilicate Na
2
Si
2
O
5
NS
2
Sodium calcium silicate Na
4
CaSi
3
O
9
N
2
CS
3
Sodium calcium silicate Na
2
Ca
2
Si
3
O
9
NC
2
S
3
Sodium calcium silicate Na
2
Ca
3
Si
6
O
16
NC
3
S
6
O
Point O is the ternary eutectic,
at 725ºC, with the composition
5.2% CaO , 21.3% Na2O and
73.5% SiO2
35. Liquidus phase relationships within the three-component system SiO2-CaO-Na2O go well beyond those relevant for glass
manufacture.
Consequently, Figure 4 focuses on the silica-rich corner of the triangular diagram, as this includes most glass compositions. In
this region, the silica mineral on the liquidus is cristobalite, tridymite or quartz (depending on temperature), with very steep
temperature gradients particularly towards more sodic compositions. Towards the lime apex, a field of two liquids is drawn; in
this field, liquid compositions separate out into two contrasting liquids, one silica-rich and one lime-rich.
These two liquids are immiscible in the same way that oil and water are immiscible, and like a good mayonnaise they are
opaque to light and can be quenched to produce an opaque white solid. The other liquidus fields show shallower temperature
gradients.
On the boundaries between them arrows are marked to show the "downhill direction". These all converge on a single point,
where the temperature at which liquid can exist is lowest, which is a ternary eutectic. The ternary eutectic composition can be
read from the compositional axes and corresponds to 5% CaO, 21% Na2O, and 74% SiO2. The minimum temperature can be
read from the contours is 725°C.
In order to decide on the optimum blend of ingredients required to make a soda-lime-silica glass, the ternary liquidus diagram
can be used to indicate the temperature required to initiate melting. The ternary eutectic composition is therefore the one
which appears to be ideal for glass manufacture, as it will begin to melt at the lowest temperature, saving energy and
manufacturing costs. Melting is carried out at 1600°C to give enough superheat to ensure that all of the solid grains within the
raw materials dissolve within the liquid and to ensure that the viscosity of the liquid is sufficiently low that gases can escape.
Compositions which are more silica-rich have a rapidly rising liquidus temperature, and may not completely melt, leaving a
glass which contains crystals of a silica mineral or bubbles and appears frosted. It is therefore important to use this and similar
diagrams not only to design batch mixes but also to diagnose problems which arise when glasses are not correctly made.
The sources of soda and lime are respectively sodium carbonate (soda ash) and limestone (dolomite is used if magnesium is
needed). These materials decompose on heating with the loss of carbon dioxide. Thus, in the formulation of batches consisting
primarily of silica sand, limestone and soda ash, proportions must be corrected to take into account the loss of carbon dioxide
so that they correspond to the compositions required for the finished glass. In order to carry out this correction, relative
atomic masses (atomic weights) are used to determine the proportions of CaO within CaCO3 and Na2O in Na2CO3:
Relative atomic masses: Ca = 12 ; O = 16 ; Na = 23 ; Ca =40
Relative molecular masses:
CaO = 56 ; Na2O = 62; CO2 = 44, CaCO3 = 100; Na2CO3 = 106
• Therefore;
100 tonnes of limestone (CaCO3) yields 56 tonnes of CaO and 44 tonnes of CO2. and
100 tonnes of soda ash (Na2CO3) yields 100 x 62/106 = 58 tonnes of soda and 42 tonnes of CO2
CHEMISTRY OF GLASS MANUFACTURE (Cont.)
36. Glass Industries
The World Glass Industry has a gross production value totaling $82.3
billion
Fig. 14
www.icem.org/events/ bled/matdocen.htm
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 36
37. Recycling of Glass
• Recycle of glass is mostly used for packaging
• Recycle process
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 37
38. Virtification
Definition:
a new technology has been
discovered to use recycle glass for
radioactive waste management
Process:
melt glass together with
radioactive waste in barrels or
some other container
glass will then bind up with
radioactive contamination into a
huge glass block
radioactive waste is bond by the
glass and become immobilized
keep radioactive waste from
interacting with water, stop
spreading the waste
Fig. 20
www.vitrification.com/ vitrification.htm
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 38
39. Good & Bad of Virtification
Benefit of virtication:
Prevent radioactive waste
pollution
Minimize the amount of glass
waste produced
Increase the efficiency of glass
use (to stabilize hazardous
waste)
High volume reduction of waste
Landfill space can be saved
Volume percent of vitrified product
compared to the original waste volume
Fig. 21 www.vitrification.com/ vitrification.htm
21 November
Prof. Dr. H.Z. Harraz Presentation Glass 39