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Roasting

Roasting is heating the material (such as minerals) rather than melting to change its chemical composition or physical properties, it is the reaction process that the solid material doesn’t melt under the high temperature. There are oxidation, pyrolysis, reduction, halogenation, etc., roasting is usually used for inorganic chemical and metallurgical industries. Burn according to the production process, roasting can be divided into two kinds of method-expansion and sintering. Expansion is to burn raw materials up to the temperature of melting, so as to produce gas and expand raw materials. Sintering is heating the raw materials up to melt it, so as that the entire particles are bonded together.

Roasting Without Additives and Roasting with Additive:

Roasting without additives, also known as calcine, can be divided into 4 types according to uses:
1. Decomposition of minerals, such as work limestone to make the calcium oxide by the way of chemical processing, while getting the carbon dioxide gas;
2. Activation of minerals, which is aimed at changing the mineral structure, making it easy to decompose, for example: roast the kaolin up to dehydrate, and have porous structure, easy to further processing of alumina;
3. Removal of impurities, such as desulfurization, removal of organic matter and adsorbed water, etc;
4. Transformation of crystal, such as roast crystalline titanium dioxide to change its structure and improve their nature of using.

Roasting With Additive

Additives can be the gas or the solid, solid additives also have the role of flux, so as to lower the melting point of the raw materials, and speed up the reaction rate. By a variety of different types of additives:

There are Several Types of Roasting:

1. roasting of Oxidation
2. roasting of Reduction
3. roasting of Chlorination
4. roasting of Sulfation

Other Beneficiation Methods

Cyanidation
Electrostatic Beneficiation
Flotation Beneficiation
Gravity Separation Beneficiation
Magnetic Separation
Wet Separation