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Questions and Answers
Is gypsum a hydraulic binder?
Is gypsum a hydraulic binder?
False
Pure gypsum is a hard crystalline mineral that cannot be scratched by a fingernail.
Pure gypsum is a hard crystalline mineral that cannot be scratched by a fingernail.
False
Low burning type of gypsum is manufactured at a temperature of about 160°C.
Low burning type of gypsum is manufactured at a temperature of about 160°C.
True
Extra strong gypsum is used for the manufacture of moulds.
Extra strong gypsum is used for the manufacture of moulds.
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Gypsum is heated to a temperature up to 200°C during the manufacturing process.
Gypsum is heated to a temperature up to 200°C during the manufacturing process.
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Describe the unique property of gypsum when heated and the subsequent behavior when water is added to the powder.
Describe the unique property of gypsum when heated and the subsequent behavior when water is added to the powder.
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How is low burning type gypsum manufactured and at what temperature?
How is low burning type gypsum manufactured and at what temperature?
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What is the classification of gypsum binders based on burning and their respective manufacturing processes?
What is the classification of gypsum binders based on burning and their respective manufacturing processes?
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How is extra strong gypsum manufactured and what is its specific use?
How is extra strong gypsum manufactured and what is its specific use?
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What are the initial steps in the manufacture of gypsum?
What are the initial steps in the manufacture of gypsum?
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Pure gypsum is a ______ crystalline mineral and is very soft that it can be scratched by a finger nail.
Pure gypsum is a ______ crystalline mineral and is very soft that it can be scratched by a finger nail.
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Gypsum has a unique property of ______. When heated it loses the combined water and easily turns into powder. When adding water to the powder it can easily be shaped and moulded, and in a short time it hardens.
Gypsum has a unique property of ______. When heated it loses the combined water and easily turns into powder. When adding water to the powder it can easily be shaped and moulded, and in a short time it hardens.
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Gypsum binders are classified according to burning: 1- Low burning type is manufactured by heating dehydrated gypsum to a temperature of about ______ °C.
Gypsum binders are classified according to burning: 1- Low burning type is manufactured by heating dehydrated gypsum to a temperature of about ______ °C.
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Gypsum may also be classified according to strength: 1- Low strength gypsum — Obtained by heating natural gypsum rock at normal pressure, the resultant gypsum is very hygroscopic (60–65%) and ______ (40%).
Gypsum may also be classified according to strength: 1- Low strength gypsum — Obtained by heating natural gypsum rock at normal pressure, the resultant gypsum is very hygroscopic (60–65%) and ______ (40%).
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Gypsum manufacture starts with 1- Extracting the raw gypsum material and then grinding into a fine powder. 2- Heated to a temperature up to 200 °C in special furnaces where they can control the temperature, here the ______ has separated in whole or in part of calcium sulphate, which represents the water element basis.
Gypsum manufacture starts with 1- Extracting the raw gypsum material and then grinding into a fine powder. 2- Heated to a temperature up to 200 °C in special furnaces where they can control the temperature, here the ______ has separated in whole or in part of calcium sulphate, which represents the water element basis.
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Study Notes
Properties of Gypsum
- Pure gypsum is a hard crystalline mineral that cannot be scratched by a fingernail.
- Pure gypsum is a soft mineral that can be scratched by a fingernail.
Unique Property of Gypsum
- When heated, gypsum loses the combined water and easily turns into powder.
- When water is added to the powder, it can easily be shaped and molded, and in a short time it hardens.
Manufacturing of Low Burning Type Gypsum
- Low burning type gypsum is manufactured by heating dehydrated gypsum to a temperature of about 160°C.
Classification of Gypsum Binders
- Gypsum binders are classified according to burning: Low burning type and Extra strong type.
- Gypsum binders can also be classified according to strength: Low strength gypsum and Extra strong gypsum.
Extra Strong Gypsum
- Extra strong gypsum is used for the manufacture of molds.
- Extra strong gypsum is manufactured by heating gypsum to a temperature up to 200°C.
Initial Steps in Gypsum Manufacture
- Extracting the raw gypsum material.
- Grinding the raw material into a fine powder.
- Heating the powder to a temperature up to 200°C in special furnaces.
- At this stage, the water element (calcium sulphate) is separated in whole or in part.
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Description
Test your knowledge on the definitions and properties of gypsum and lime. Learn about gypsum's unique property of molding and its behavior when heated or mixed with water.
