Wollastonite Production Equipment

Wollastonite is a calcium metasilicate mineral with a chemical formula of CaSiO3.


Ca is often replaced by Fe, Mg, Mn, Ti, Sr ions, forming isomorphs, so pure wollastonite in nature is rare.
 

Wollastonite classification

Three homogeneous multiple variants
2 low-temperature image variants: triclinic wollastonite, monoclinic parawollastonite
1 variant of high temperature phenomenon: commonly known as pseudo-wollastonite

The common wollastonite in nature is mainly TC-type wollastonite with a low-temperature triclinic chain structure, and the other two variants are rare.


 

Physical and chemical properties of wollastonite

1. Low temperature triclinic wollastonite crystal
2. Mohs hardness 4.5~5
3. Add hydrochloric acid and boil to produce flocculent silica gel
4. Small thermal expansion coefficient
5. Density 2.78~2.91g/cm3
6. Melting point 1544°C
7. Glass luster to pearl luster
8. Low ignition loss
9. Often white and off-white
10. Soluble in acid
11. Has good fluxing properties


 

Production distribution

The world's wollastonite resources are rich, the total resource is estimated to be more than 800 million tons, but the distribution is very uneven. Only more than 20 countries have discovered wollastonite deposits, mainly distributed in Asia, China, India, Kazakhstan, Uzbekistan, Tajikistan, Mexico, the United States and other countries in the Americas, with proven reserves of 300 million tons; in addition, Finland and Turkey , Namibia, South Africa, Sudan, Canada and Yugoslavia have also discovered wollastonite deposits.
 

Wollastonite processing technology

 

01 Beneficiation

Main method
Sorting, single magnetic separation, single flotation, magnetic separation-flotation (or electric separation) combined process.

Main method
Reduce iron content and separate calcite.

02 Processing

Main production equipment for ultrafine wollastonite (dry production)

Ultrafine vertical mill

Production of high-end ultra-fine wollastonite powder from 325 mesh to 3000 mesh

Superfine ring roller mill

Production of mid-to-high-end ultra-fine wollastonite powder from 200 mesh to 2500 mesh

High-pressure suspension roller mill

Produce 80-325 mesh low-end ultra-fine wollastonite powder



 

Wollastonite wet purification (wet production)

Flotation or wet strong magnetic separation is followed by ultra-fine pulverization. The wet process can be used. After wet pulverization to the required product fineness, dehydration (filtration and drying) is performed.

Wollastonite wet purification (wet production)
Flotation or wet strong magnetic separation is followed by ultra-fine pulverization. The wet process can be used. After wet pulverization to the required product fineness, dehydration (filtration and drying) is performed.

03 Surface modification

 

Organic surface modification Method: surface chemical coating method

Modifiers: silane coupling agents, titanate and aluminate coupling agents, surfactants and methyl methacrylate, etc.
 

Organic surface modification Method: surface chemical precipitation method

Modifier: Coated with nanometer calcium silicate, silicon dioxide and nanometer calcium carbonate on the surface.
 

Wollastonite powder application field

Wollastonite powder has needle-like, fibrous crystal morphology, high whiteness and unique physical and chemical properties. It is widely used in ceramics, paints, coatings, plastics, rubber, chemicals, papermaking, welding electrodes, metallurgical protective slag and as asbestos Substitutes, etc.