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Processing of wollastonite and its application in coatings

Wollastonite is a kind of chain metasilicate, which is generally fibrous and needle-shaped. Because of its special crystal morphology and crystal structure, wollastonite has good insulation, high whiteness, good dielectric properties and high heat and weather resistance. Because wollastonite is widely used in ceramics, chemical industry, metallurgy, papermaking, plastics, coatings and other fields.

Processing of wollastonite:

1. Mineral processing

The main mineral processing methods of wollastonite at home and abroad are manual separation, single magnetic separation, flotation, magnetic separation-flotation (or electrostatic separation) combined process. The main purpose of mineral processing is to reduce iron content and separate calcite.

Hand selection

The rich ore blocks are manually selected in the mining field or the wollastonite-rich ore blocks are manually selected on the conveyor belt after crushing. Hand selection is suitable for ores with good quality.

Single magnetic separation

The main associated minerals in wollastonite rocks, such as diopside and garnet, belong to weak magnetic minerals, but wollastonite basically does not show magnetism, so wollastonite can be separated from each other by dry or wet high-intensity magnetic separation technology, so that a large number of iron-containing minerals can be separated and the purity of products can be improved.

Single flotation

According to the difference of physical and chemical properties between wollastonite and calcite, flotation can effectively separate them from each other, thus improving the purity of wollastonite products.


Magnetic separation-flotation combined process

This method is suitable for the treatment of low-grade wollastonite. Firstly, weak magnetic minerals are separated by dry or wet magnetic separation. Then wollastonite is separated from calcite, quartz and other minerals by flotation. Separation of wollastonite and calcite by flotation. There are two main technological processes for minerals such as quartz.

① Reverse flotation scheme of anion collector

Calcite is a carbonate mineral, and wollastonite and quartz belong to silicate minerals. Based on this, according to the surface electrical difference between them, calcite was separated by flotation by changing the PH value of pulp medium and using an adjusting agent. Then quartz and wollastonite are separated by flotation. Generally, oxidized paraffin soap is used as the collector of calcite, and sodium silicate is used as the inhibitor of wollastonite and quartz.

Positive flotation scheme of cationic collector

This method mainly adjusts the surface electrical properties of wollastonite and calcite minerals to make them have different potential, so that wollastonite is preferentially floated out by electrostatic adsorption with cationic collectors, while calcite is left as tailings in the flotation tank. The flotation operation is divided into two stages: in the first stage, wollastonite and silicate minerals are floated together as foam products with amine collectors, and calcite is left in the tank; In the second stage, mixed collectors of amine ions and anions are used to float silicate impurities, and wollastonite is recovered as a product in the tank.

2. Grinding and processing of acicular wollastonite

Wollastonite powder is a short fibrous inorganic powder. In some application fields, such as ceramics, glass-ceramics, metallurgical protective slag, etc., only asbestos substitutes, paper pulp substitutes, reinforced fillers of plastics and rubber, and some coating fillers are required, not only for particle size discovery and particle size distribution, but also for the aspect ratio of fibrous particles. Wollastonite powder with high aspect ratio (>10) can replace asbestos fiber, paper fiber and advanced reinforcing filler of polymer-based composites such as plastics and rubber, which has great application value and economic value. Therefore. The processing technology of high aspect ratio wollastonite needle powder is one of the main deep processing technologies of wollastonite.


Contact: Bruce King

Phone: +86 18651865975

Tel: +86 025-58895705


Whatsapp:+86 18651865975

Add: Gaotuan Town, Fushan District, Yantai City, Shandong Province, China