Yuan Lei's Little Knowledge | Kaolin Mineral Processing Method and Process
The mineral composition of kaolin is mainly composed of kaolinite, halloysite, hydromica, illite, montmorillonite, quartz, feldspar and other minerals. Kaolin is widely used in papermaking, ceramics and refractory materials, coatings, rubber fillers, enamel glaze and other aspects.
In order to separate non-clay minerals and organic matter such as quartz, feldspar, mica, iron minerals and titanium minerals in kaolin and produce kaolin products that can meet the needs of various industrial fields, in addition to the purification of kaolin by gravity separation, flotation and magnetic separation, the kaolin is sometimes treated by deep processing methods such as chemical bleaching, chemical purification, calcination and surface modification.
Beneficiation Method of Kaolin
1. Water medium float-sink method
Water medium float method refers to the use of water as a medium, the use of various minerals in the water of the floating speed and solubility of different, the useful minerals and impurities of mineral separation of a beneficiation purification processing method. It is mainly used to remove impurity minerals such as feldspar and quartz in kaolinite ore, so that the purity and whiteness of kaolin can be improved.
Classification is the use of mineral particle size or density difference to separate minerals, according to different circumstances, the classification method is not the same. If the mineral particle size difference is large, it is generally classified with a screen; if the difference is small, it is screened according to density. Its function is the same as that of the water medium float-sink method.
3. Magnetic separation
The application of magnetic separation is to use the magnetic differences of various ores or materials to select other processes under the action of magnetic force and other forces. It is more effective for removing high magnetic minerals such as magnetite and ilmenite or iron chips mixed in the processing process.
Flotation refers to the technical method of separating useful minerals from ores according to the different physical and chemical properties of the surface of mineral particles. It is a commonly used method in kaolin purification at present. The purpose of flotation is to remove colored minerals and improve whiteness. Flotation is generally divided into carrier flotation method and carrier free flotation method.
5. Chemical purification
Chemical purification is the use of minerals containing some associated impurities minerals with acid soluble or alkali soluble and other characteristics, and the use of acid or alkali to dissolve a method of rejection. This process is more cost-effective than direct bleaching with bleach and has a high degree of whiteness in purification. However, chemical purification still has a certain impact on the environment, and may affect the original properties of kaolin.
6. Microbiological method
Microbial purification processing technology is a new method to purify and whiten kaolin, which is characterized by less investment, low cost, low energy consumption and low environmental pollution. The microbial processing and purification technology of minerals includes microbial leaching technology and microbial flotation technology. The technology is the use of microbial and mineral depth between the role of mineral lattice destruction, so that the useful components dissolved out of an extraction technology.
7, Chemical Bleaching
Used as a pigment, filler and coating of kaolin, its whiteness and brightness directly affect the level of its value. Adding a bleaching agent such as hydrosulfite to reduce the high-valent iron of limonite and hematite in kaolin to soluble ferrous iron, or adding an oxidant to oxidize pyrite and dye impurities to improve the whiteness of kaolin.
8. Ultrafine grinding
In order to meet the requirements of high fineness of kaolin in papermaking, plastics and rubber products industries, the fineness of kaolin must be increased to improve the quality of products. The ultrafine grinding process mainly includes grinding and stripping method, high pressure extrusion method and air flow crushing method.
9. Calcination processing
When calcined at 800~1000 ℃, kaolin loses water, phase transformation, and some impurities volatilize, improve the whiteness and insulation of kaolin, and produce cable and rubber plastic filler. Calcination is a necessary processing method for coal (hard) kaolin.
10, Surface Modification
In the application process of kaolin, modification, as an important deep processing method, is based on the active group of kaolin (including aluminum alcohol group, silanol functional group, etc.), and the process characteristics of kaolin are changed by mechanical, physical and chemical methods to meet the application requirements in various fields and industries.
Method, kaolin, mineral, purification, flotation, technology, utilization, microorganism, chemistry
The difference between barium sulfate（BaSO4） and barium sulfite（BaSO3）
Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.