Chinese kaolin mineral processing method
In order to separate non- clay minerals and organic matter such as quartz , feldspar , mica , iron minerals and titanium minerals in kaolin, kaolin products can be produced to meet the needs of various industrial fields, except for re-election, flotation, magnetic separation and the like. 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 particle size classification).
2. High-gradient magnetic separation, using magnetic magnetic medium to generate magnetic field strength above 1 600kA / m, removing Fe2O3 and TiO2 in kaolin, producing paper coatings and advanced ceramic raw materials.
3. Selective flocculation, by adding flocculant, selectively separating impurities such as fine-grained quartz, pyrite, alum, etc., to produce blade-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. Peeling, using a fine medium ball to produce a grinding and stripping action in the stripping machine, separating the kaolin aggregate particles into flake crystals, and producing a blade coating grade kaolin having a particle size of less than 2 μm and a content of more than 90%.
6. Calcination, when calcined at 800～1 000°C, the kaolin loses water, the phase transforms, and some impurities volatilize, improve the whiteness and insulation of kaolin, and produce cable and rubber plastic filler. Calcination is a coal-based processing methods (hard) kaolin necessary.
7. Surface modification, kaolin is coated with a coupling agent or the like to increase the amount of the kaolin added in the plastic rubber, and is used for treating a kaolin filler for rubber plastics. The processing of kaolin in China's kaolin process is divided into dry and wet processes.
The dry method generally breaks the mined ore produced by the crusher to about 25 mm and feeds it into the cage crusher to reduce the particle size to about 6 mm. 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.
Chinese kaolin dressing
1. China Kaolin Company Guanshan Concentrator
The kaolinite ore from the Guanshan Concentrator of China Kaolin Company originates from the two mining areas of Yangxi and Yangdong in the western suburbs of Suzhou. It is a soft and sandy kaolin. The main components of the ore are kaolinite and halloysite, followed by montmorillonite, and a small amount of quartz, pyrite, alum and organic impurities. The mineral processing process is shown in Figure 4.22.9. The double-shaft vertical sizing machine for mashing is treated by sedimentation tank concentration, filter press dehydration and chain plate dryer drying. Scraper-coated grade kaolin can be produced when using water rafts and bleaching operations. The design production capacity of Guanshan Concentrator is 50 000t per year, the maximum grain size of ore is 300mm, the maximum particle size of the pulping machine is 50mm, the maximum grain size is 0.5mm, the ore grade Al2O3 is 26%~35%, the ore moisture is 20%-23%, tailings The grade Al2O3 is 20%~24%, and the recovery rate of ore dressing is 61.97%.
2. Zhanjiang Kaolin Joint Development Company
The company's concentrating plant is located in Zhanjiang City. The original mine is from the Shanshan kaolin mining area of ​​Zhanjiang City and belongs to the weathered residual sandy kaolin mine. The main mineral is kaolinite, halloysite, mica and water, followed by feldspar, quartz, muscovite, small amounts of harmful impurities as hematite, limonite, siderite, white titanium, rutile and ilmenite . The process of the concentrator is shown in Figure 4.22.10. The design capacity of the concentrator is 43 500t per year. The ore size is 30mm, the moisture is 24%~25%, and the ore recovery rate is 81.5%. The main products are paper coating grade, filler grade and ceramic grade kaolin.
3. Shanxi Jinyang Calcined Kaolin Co., Ltd.
The company is located in Cangzhou City, Shanxi Province. The original mine is from the coal seam of No. 4 coal seam of the Taiyuan Formation of the Wujia Kiln in Datong City. It is a coal-series kaolin. The kaolinite content in the ore is more than 95%, SiO2 44.10%, Al2O3 39.34%, Fe2O3 0.33%, TiO2 1.00%, CaO 0.24%, MgO 0.11%, K2O 0.03%, Na2O 0.08%, MnO 0.003%, S 0.022%. The ore is of good quality and rich in resources. The process of the concentrator is shown in Figure 4.22.11. The designed production capacity of the ore dressing plant is 10 000t/a, and the quality of the product is shown in Table 4.22.22 and Table 4.22.23. In the product, the content of -2μm is 92%, the whiteness is more than 93%, the pH is 6.7-7.6, the moisture is less than 0.5%, and the viscosity is 74 (500mPa·S solid content). The quality meets the standards of American paper coating grade calcined kaolin. The maximum ore size of the ore is 350mm. It is crushed to -35mm by hand, washed and smashed to -325mm by 4R3216 Raymond mill. It is added to water and pulped. It is wet-grinded into 625 mesh by BP80 stripper. The slurry is directly spray-dried. Into the UK imported indirect heating rotary kiln calcination, after the burning through the United States imported dispersing machine depolymerization, and then using the German import classifier classification, grading product packaging to be shipped.
Direct Black 38,Direct Black 19,Direct Black Ex,Direct Fast Black G
Qingdao Langke Co.,Ltd. , https://www.langkedyes.com