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Wollastonite , powder and lump
Wollastonite is an industrial mineral comprised chemically of calcium, silicon and oxygen. Its molecular formula is CaSiO3 and its theoretical composition consists of 48.28% CaO and 51.72% SiO2. Natural wollastonite may contain trace or minor amounts of various metal ions such as aluminum, iron, magnesium, potassium and sodium. Wollastonite is rarely found by itself and generally contains other minerals like calcite, garnet and diopside that are removed during processing . With wollastonite as raw material, produced by advanced grinding and coating techniques, YW series of intensifiers are perfect new-style intensifiers for resin products like PA, PP, PE, PET, PVC, ABS, etc
DETAILS OF Wollastonite :
1) 100 mesh to 325 mesh
2) When sufficient wollastonite is added to ceramic material, the baking temperature can be decreased, and the baking duration greatly shortens to one rapid low temperature bake, thus saving fuel and producting costs
3) At the same time the mechanical properties are improved, cracks and streaks on the products are eliminated and quality is improved.
APPLICATIONS:
Plastics: In plastics, wollastonite improves the durability of the composite due to its acicular or needle-like structure. It also enhances electrical insulating properties, adds fire resistance, and improves dimensional stability. Finer particle size grades provide improved scratch and impact resistance compared to other materials. The application of surface treatments like silanes on the wollastonite substrate changes the mineral from a utilitarian filler to a functional component of a polymer composite. This in turn adds performance values which the base resin alone does not possess. Optimum performance is created by properly matching the correct coupling agent at the right concentration level to the polymer system. Overall, the benefits of a surface modified wollastonite are improved physical properties, improved processing along with improved dispersion of the resin. Construction: Wollastonite has found application as a substitute for asbestos in fire-resistant building products used in the construction industry. As a functional additive, wollastonite improves flexural and impact strengths. Its low thermal conductivity and high aspect ratio structure also makes wollastonite an attractive addition for applications requiring fire resistance. Wollastonite finds application in interior and exterior construction boards, roof tiles, shaped insulation products, sheets, panels and sidings. Ceramics: Wollastonite can be used in a variety of ceramic applications including ceramic glazes and bodies, enamels, frits, fluxes and in sanitaryware. This industrial mineral is a source of CaO to alkaline glaze formulations to improve the strength of the glaze. Wollastonite also has a low LOI ( 1%) which gives minimal gas evolution during firing resulting in a smooth surface with diminished pinholing. Due to its acicular structure, wollastonite improves green strength and reduces crazing and checking especially during rapid heating and cooling. It has a low sintering temperature (approximately 991-1196C) which is comparable to that of most natural frits.
Paints and Coatings: In coatings, fine acicular wollastonite particles act as flattening agent and allow paint to settle out after application to produce dry film of uniform thickness. Wollastonite’s interlocking particles properties improve toughness and durability of the coating with excellent tint retention, scrub, and weather resistance. High brightness and whiteness of wollastonite reduce pigment load and typically very low oil absorption, reduces the volume of binder required and contributes to lower pigment input costs. Wollastonite also act as a pH buffer for improved in-can paint stability over long period. The acicular structure and alkaline nature of wollastonite also make it an ideal auxiliary pigment in industrial coatings and primers for better corrosion resistance. Metallurgical: In metallurgy wollastonite is honored due to its low water solubility, low loss on ignition & its Ca–Si ratio. Wollastonite is commonly added into formulated powders for steel casting and welding. CaO/SiO2 ratio of 1 easily absorbs Al2O3 that is determining to finished steels. Wollastonite addition to metallurgical fluxes provides ready fusibility, good insulating and low viscosity properties. As wollastonite is a natural, low temperature flux wollastonite is accepted in fluxing formulations for the continuous casting of steel. Wollastonite formulated casting powder is applied when molten steel is poured continuously from a ladle or tundish, to maintain surface defects, prevention of oxidation of steel, lubricates the mold wall and absorbs harmful intrusions.
Specification
Physical-chemical index (%):
Model | SiO2 (%) | CaO (%) | Fe2O3 (%) | Al2O3 (%) | MgO (%) | LOI (%) | Whiteness (%) |
E0713A | ≥49 | ≥43 | ≤0.3 | ≤0.8 | ≤0.8 | ≤1.0 | ≥90 |
E0713B | ≥49 | ≥43 | ≤0.35 | ≤1.0 | ≤1.0 | ≤2.0 | ≥88 |
E0714, Wollastonite, powder and lump