Needle wollastonite

Wollastonite is a calcium silicate mineral with a chemical formula of CaSiO3, and it has three polymorphic forms; Two low-temperature variants, namely triclinic wollastonite and monoclinic ortho wollastonite, one high-temperature variant. The commonly found wollastonite in nature is mainly TC shaped wollastonite with a low-temperature three diagonal chain structure, and the other two variants are rare. In the TC type wollastonite structure, calcium forms octahedra with oxygen through six fold coordination, and these calcium octahedra share edges to form chains, with three calcium oxygen octahedral chains forming bands. Due to its needle like or fibrous particle morphology, high whiteness, and unique physical and chemical properties, wollastonite is widely used in ceramics, coatings, plastics, rubber, metallurgy, chemical industry, papermaking, welding electrodes, as a substitute for asbestos, abrasive binder, glass, glass fiber, and cement ingredients.
 The surface modification of wollastonite can be divided into organic surface modification and inorganic surface modification. （1） Organic surface modification: For wollastonite powder, it can be used as an inorganic reinforcing filler for high polymer materials such as plastics, rubber, nylon, etc. However, untreated wollastonite powder has poor compatibility with organic polymers and is difficult to uniformly disperse in polymer based materials. It is necessary to carry out appropriate surface organic modification to improve its compatibility with polymer based materials and enhance the filling and reinforcement effect. （2） Inorganic surface modification: The technical background of inorganic surface modification is that wollastonite, as a high polymer filler, often causes the color of the filling material to darken, and the wear value is high, which makes it easy to wear processing equipment; Inorganic surface coating modification can improve the color and reduce the wear value of polymer materials filled with wollastonite fibers.