Production Process and Overview of Washed Kaolin

Time:

2024-04-18 20:24

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Washed kaolin is a non-metallic mineral, mainly clay and claystone dominated by kaolinite group clay minerals.

 

I. Chemical composition

 

Washed kaolin is mainly composed of four elements: silicon, aluminum, oxygen and hydrogen, and its chemical formula is Al2Si2O5(OH)4.

 

Among them, the content of Al2O3 is about 35.8%, the content of SiO2 is about 46.3%, and the content of OH is 13.2%.

 

This composition makes the washed kaolin have a certain acidic oxidizing property, which can react with acid, alkali and other substances.

 

II. Physical Properties

 

Appearance: Washed kaolin usually appears as a white, delicate, fluffy soil, and the color may be darker due to the presence of more impurities and iron oxides.

 

Purity and quality: Compared with selected kaolin, washed kaolin is relatively weaker in terms of purity and quality, but after the washing process, its impurities and rust and other substances have been effectively separated and washed, which is relatively cleaner.

 

Acidity and alkalinity: The acidity and alkalinity of washed kaolin is neutral.

 

III. Process Characteristics

 

As a coating or film layer, washed kaolin has good anti-abrasion and covering ability and non-shrinkage property, which is widely used in the field of coating.

 

Under high temperature conditions, washed kaolin will undergo dehydration reaction, lose water and become more stable and hard.

 

IV. Production process

The production process of washed kaolin mainly includes the following steps:

 

Ore crushing: the original kaolin usually exists in the form of large blocks, which are firstly crushed into small particles of ore through quarrying and crusher.

 

Ore grading: The crushed kaolin ore enters a vibrating screen for grading, and is generally divided into two grades: coarse-grained kaolin and fine-grained kaolin. Coarse-grained kaolin can be used in ceramics, building materials and other fields, while fine-grained kaolin is the raw material for producing high-purity kaolin products.

 

Washing: Fine-grained kaolin is fed into the washing machine for washing, by injecting water to flush the ore, remove impurities and separate kaolin from other particles.

 

Sedimentation: The washed kaolin slurry enters the sedimentation tank for sedimentation, and the kaolin particles will settle at the bottom.

 

Filtration: The kaolin slurry after precipitation enters into the filter, and the solid particles in the slurry are separated out through the filter mesh to remove the residual impurities and water.

 

Drying: The kaolin dewatering slurry obtained after filtration is dried, generally using constant temperature and humidity drying oven.

 

Packing: After drying treatment, kaolin is made into powder or granule, and packaged according to different applications.

 

In addition, according to the nature of kaolin raw ore, other treatments, such as magnetic separation, bleaching, press filtration, etc., may be required to further improve the purity and quality of kaolin.

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