Kaolin Dressing Process

In order to separate organic matter and non-clay minerals in kaolin, like quartz, feldspar, mica, ore minerals, titanium mineral etc., produce kaolin products which can meet requirements of every industrial field, in addition to gravity concentration, flotation, magnetic separation which can purify kaolin and remove impurities, deep processing methods are needed to treat kaolin, like chemical bleaching, superfine peeling, calcine, surface modification, etc.

1. Hydraulic Separation

Hydraulic separations include spiral classification (separate rough sand of��1mm ), settling pond classification (separate fine sand of��0.053mm), hydraulic cyclone classification (separate fine sand of-0.053mm), and centrifugal classification or diameter hydro-cyclone classification (separate superfine sand of 0.002��0.010mm).

2. High-gradient Magnetic Separation

Make use of magnetic matrix to produce magnetic density above 1 600kA/m so as to remove Fe2O3 and TiO2 in kaolin. So the processed kaolin can be used to produce dope of papermaking, and superior raw materials of ceramic. Magnetic separator and other ore dressing plants are used.

3. Selective flocculation

Adding flocculants, so impurities like quartz of fine grains, pyrite, and alunite are selectively separated. So blade coater-grade kaolin is produced.

4. Chemical Bleaching

Add bleacher like rongalite, so high valance iron of limonite, hematite in kaolin is reduced to soluble ferrous iron; or add oxidant, pyrite oxide and dyeing impurities to improve whiteness of kaolin.

5. Delaminating

In stripping machine, fine dielectric sphere is stirred to generate grinding and peeling function, so as to separate aggregate particles of kaolin into sheet crystal. Therefore blade coater-grade kaolin with 90% of grains smaller than 2��m can be produced.

6. Calcination

When calcining in the temperature of 800��1 000��, kaolin will loss water, phase transformation happens, and part of the impurities volatilize; so whiteness and insulativity of kaolin are improved, which will make kaolin used to produce cable and filler of rubber and plastic. Calcining is a kind of processing method of (hard) kaolin of coal series.

7. Surface Modification

Kaolin is wrapped by using resin acceptor or other agents, so its additive amount in rubber and plastic is increased. Surface modification is adopted to treat kaolin which is used as filler of rubber and plastic.

Application of Kaolin

Kaolin is a kind of important nonmetallic ore. Kaolin, mica, quartz and calcium carbonate together, are called the four nonmetallic ores. Kaolin has wide application to agriculture and industries, like ceramic, rubber, plastic, artificial leather, cement, fireproofing, chemistry, etc.

Kaolin Processing Plants

1. Kaolin Dressing Process
2. Kaolin Ore Dressing Methods