Kaolin mineral processing and processing methods (1)

( 1 ) Processing method of mineral processing

      Quartz, feldspar, mica, iron minerals, titanium minerals and other non-clay minerals and organic matter in the separated kaolin, produced to meet various needs in the area of industrial kaolin products, in addition to re-election, flotation, magnetic separation of kaolin In addition to purification, the kaolin is sometimes treated by deep processing methods such as chemical bleaching, ultrafine stripping, calcination, and surface modification.

   
      1. hydraulic classification

  

      Hydraulic classification includes spiral classification ( separation + 1mm Coarse sand ) , sedimentation tank classification ( separation + 0 . 053mm Fine sand ) , hydrocyclone classification ( separation -0 . 053mm Fine sand ) , centrifugal classifier or small diameter hydrocyclone classification ( for 0 . 002 ～ 0 . 010mm Ultra-fine grain grading ) .

 

       2. HGMS

 

      The magnetic field strength of 1 600 kA/m or more is generated by using a magnetic magnetic medium to remove Fe ₂ O ₃ and TiO _{2 in} kaolin, and a papermaking paint and a high-grade ceramic raw material are produced.

  

       3. Selective flocculation

   
      By adding a flocculant, impurities such as fine-grained quartz, pyrite, and alumite are selectively separated to produce a knife-coated grade kaolin. Common flocculant hexametaphosphate, sodium phosphate, ammonium polyacrylamide, water glass.

   
       4. chemical bleaching

  

  Adding bleaching agent such as insurance powder to reduce the high-valent iron of limonite and hematite in kaolin to soluble ferrous iron, or adding oxidizing agent to oxidize pyrite and dyeing impurities to improve the whiteness of kaolin.

 

      5. Stripping

   
      Stripping with stirring, a fine media mill grinding stripping ball in effect, kaolin particles are separated into an aggregate of crystal flakes, production size of less than 2 μ m content of more than 90% of the blade coating grade kaolin.

 

      6. calcined

  
     At 800 to 1 000 °C When calcined, the kaolin loses water, the phase transforms, and some impurities volatilize, improving the whiteness and insulation of the kaolin, and producing cables and rubber plastic fillers. Calcination is a coal-based processing methods (hard) kaolin necessary.

 

      7. The surface-modified

 

      The kaolin is coated with a coupling agent or the like to increase the amount of the kaolin added to the plastic rubber, and is used for treating a kaolin filler for rubber plastics.

 

( 2 ) Work art flow Cheng

 

      The ore processing of kaolin is divided into two processes: dry process and wet process.

      The dry method generally breaks the produced ore through the crusher to 25mm Left and right, feed into the cage crusher to reduce the particle size to 6mm about. The hot air blown into the cage crusher reduces the moisture of the kaolin to about 10% from about 20% at the time of production . The crushed ore is further ground by a blown Raymond mill equipped with a centrifugal separator and a cyclone. The process can remove most of the sand and is suitable for processing ore with high whiteness, low sandstone content and suitable particle size distribution. Dry processing costs are low, and products are often used in low-cost fillers in industries such as rubber, plastics and paper.

       The wet processing process includes several stages of dispersing, grading, impurity sorting and product processing of the mud. The general principle process is: raw ore → crushing → slurry → sand removal → cyclone classification → stripping → centrifuge classification → magnetic separation ( or bleaching ) → concentration → pressure filtration → drying → ceramic grade or paper coating grade products.

      The general principle flow of coal-based ( hard ) kaolin processing is: raw ore → crushing → slurry → cyclone classification → stripping → centrifugal classification → concentration → pressure filtration → internal steam drying → calcination → depolymerization → filler grade or paper coating Grade kaolin.

 

( 3 ) Selection mine real Practice

 

1. China Kaolin Mountain View Concentrator