For soft kaolin and sandy kaolin, the wet beneficiation process is generally used. The raw kaolin ore is broken up under the high pressure impact of water gun, or the raw kaolin ore is pulped by a pulp rammer, and the pulp is sent to a spiral classifier for desanding by avalanche, and then separated by a hydrocyclone.
The raw ore is added with water and dispersant according to the set concentration requirements, and pulped in the mixer or pulper. The purpose of pulping is to disperse kaolin and separate it from sandy minerals and plant impurities, so as to prepare slurry of appropriate concentration for the next process.
2.Spiral classifier for grit removal
The particle size of quartz, feldspar, mica and other impurities in kaolin raw ore is coarse, while that of kaolin is fine. Most of the quartz and feldspar coarse sand can be removed by spiral classifier.
Hydrocyclone is used to separate the fine kaolin sand (fine quartz, feldspar and other impurities).
4.Classification of horizontal spiral centrifuge
The horizontal spiral centrifuge is used for classification, and the process parameters (such as separation factor) can be adjusted according to different materials to maintain the stability of product quality.
In order to obtain high quality or high quality kaolin, strong magnetic separation or high gradient magnetic separation, chemical bleaching, even flotation and selective flocculation are needed in most cases. The dyeing mineral impurities in kaolin, such as limonite, hematite, siderite, pyrite, anatase, rutile and so on, are all weakly magnetic. Therefore, the removed kaolin can be further magnetically separated by strong magnetic separator or high gradient magnetic separator.
Common chemical bleaching methods include reduction, oxidation, oxidation-reduction combined bleaching, acid leaching, etc.
High pressure feed is adopted to improve the productivity, ensure that the water content of the product is lower than 32-35%, save energy consumption and improve the working environment.
Strong drying is available.