Wollastonite origin:
Wollastonite in China is widely distributed and has large reserves. Wollastonite ore in some areas is of good quality and has good development potential. At present, more than 100 wollastonite producing areas have been discovered in 17 provinces and regions in China, with an estimated resource of nearly 200 million tons. By the end of 1996, there were 3 1 mineral deposits with proven reserves in 14 provinces and regions in China, ranking first in the world with ore reserves of132.65 million tons.
Jilin Province has the largest reserves, accounting for 40% of the total ore reserves in China. The rest are Yunnan, Jiangxi, Qinghai and Liaoning provinces, accounting for 49% of the country's retained ore reserves; Zhejiang, Hunan, Anhui, Inner Mongolia and Guangdong provinces account for10% of the national reserves; Jiangsu, Guangxi, Hubei and Heilongjiang provinces account for 1% of the national ore reserves. Jilin Lishu Wollastonite Mining Company is the largest wollastonite producer in China, with 10 mines and processing plants, with an annual output of 80,000 tons of wollastonite. Other large domestic wollastonite producers include Dadingshan Wollastonite Mining Company in Lishu County, Jilin Province, Nanfang Wollastonite Industrial Company in Xinyu City, Jiangxi Province, Changxing Wollastonite Mining Co., Ltd. in Zhejiang Province, and Xiamiao West Wollastonite Mining Company in Guangde County, Anhui Province.
In the past two years, the scientific research ability, mining equipment, processing technology and testing level of the enterprise have been greatly improved compared with previous years, new products have been continuously increased, the processing technology of needle powder, superfine powder and modified powder has been continuously innovated, reaching the international advanced level, and the deep processing capacity has soared, completely changing the business model of selling raw ore, and greatly enhancing the vitality of the enterprise. Not only the old enterprises such as Lishu Wollastonite Mining Company and Changxing Wollastonite Company have made great progress, but also some new enterprises such as Yunnan Ultrafine New Materials Co., Ltd., Liaoning Jingang Wollastonite Company, Jiangxi Xinyu South Wollastonite Company, Jiangxi Huajietai Company, Panshi Yuhuan Wollastonite Company, Huangshi Xinyi Mining Company and Dalian Global Mining Company have developed strongly and their competitiveness in domestic and foreign markets has been continuously improved. The output of wollastonite in China is increasing. At present, China has become the main producer of wollastonite powder in the world.
At present, wollastonite is mainly used in ceramic industry, accounting for about 50% of the total consumption. This is because wollastonite glazed tiles have the characteristics of low firing temperature, short firing time, high whiteness and low cost. Moreover, many domestic ceramic factories have built production lines for glazed tiles based on wollastonite. It can be said that wollastonite, as the raw material of glazed tiles, has found a more, faster, better and cheaper shortcut for the ceramic construction industry in China.
Uses of wollastonite:
Wollastonite is a kind of chain metasilicic acid, and it is also a kind of fiber and needle. Because of its special crystal morphology and crystal structure, wollastonite has good insulation, high whiteness, good dielectric properties and high heat resistance and weather resistance. Because wollastonite is widely used in ceramics, chemical industry, metallurgy, paper making, plastics, coatings and other fields.
① coating industry
High-quality wollastonite powder is used in some products of paints and coatings to replace lithopone, part of titanium dioxide and imported P820 as fillers, which can improve the leveling property of coatings. The particle shape of wollastonite is a good suspending agent for coatings, and its precipitation is soft and dispersed, which can be used as a reinforcing agent for clean coatings. Because it has a low oil absorption. It has a higher filling amount, which reduces the amount of binding substances, so the cost of the coating is greatly reduced. Wollastonite is alkaline, which is very suitable for polyvinyl acetate coating and makes the pigment disperse evenly. It can be connected with pigments suitable for acidic media, and can also be made into colorful coatings with uniform surface distribution and good spraying performance. As a filler, it can improve the corrosion resistance of steel coating. Besides waterborne coatings and polyvinyl formal, it can also be used as primer, intermediate coating, oily coating, traffic paint, sound insulation coating, fire retardant coating, etc. It can replace asbestos in asphalt coatings, and wollastonite can be used as a reinforcing agent in self-cleaning coatings. Wollastonite powder is used in ink industry to replace part of titanium dioxide and lithopone, and has also achieved ideal results.
② Application in rubber and plastics
Wollastonite powder has been used in vulcanized rubber, vinyl brick, vinyl resin, polyvinylether epoxy vinyl plastic board and phenol model. When producing epoxy resin, 50% wollastonite powder is used as filler, which has the characteristics of low water absorption in non-curing state. Wollastonite can improve the properties of polymer materials, and can be used as filler of elastic materials, which can reduce the price. This synthetic material has high thermal stability, low dielectric index and water absorption, and stable mechanical properties.
Wollastonite is widely used as filler for polypropylene, polystyrene, polyvinyl chloride and polyethylene. Compared with other fillers, wollastonite has excellent electrical, mechanical and thermodynamic properties. Adding wollastonite to polystyrene resin composition can reduce the amount of expensive pigment without affecting the quality. The application of wollastonite in polypropylene compound can also save cost. Wollastonite is often used as nylon molding material because of its low moisture content, light luster, stable shape and reinforcing properties. Wollastonite powder is used in rubber shoe soles to replace some titanium dioxide, white carbon black, clay and so on, and the effect is good. When used in rubber hose and adhesive tape, the product quality is improved and the cost is obviously reduced.
③ Application in metallurgy and refractory industry.
Wollastonite has stable chemical composition and alkalinity value close to 1, so it is an ideal raw material for metallurgical mold flux. In the early 1980s, China began to use wollastonite to produce metallurgical mold flux, and gradually expanded its varieties. Now it has been widely used in die casting, continuous casting (slab and billet), synthetic slag and stainless steel continuous casting and many other varieties. Low-grade wollastonite can be used as mold flux, so the cost is low. In recent years, the application of wollastonite in metallurgical industry has made new progress. Wollastonite is widely used in metal mold coatings, injection refined molten steel, refractory bricks, refractory insulators, ceramic insulating foams and other industries. Therefore, some foreign experts believe that wollastonite should be a kind of refractory.
④ Application in ceramic industry
Adding appropriate amount of wollastonite (middle and low grade) into ceramic raw materials can greatly reduce the sintering temperature, shorten the sintering time of products, realize rapid one-time sintering at low temperature, save a lot of fuel and obviously reduce the product cost. Because wollastonite products contain no alkali metals, they have good electrical insulation, high impact strength and shape stability, which makes wollastonite used in precision ceramics and process ceramics. Using wollastonite instead of white pigment in raw materials of glaze mud can increase glaze luster, reduce the viscosity of glaze mud and greatly reduce the cost. Wollastonite in ceramic products can prevent porcelain from cracking, microcracking, breakage and glaze defects. Because wollastonite has linear thermal expansion characteristics. Thereby reduce that flexibility of the product. Adding 1% wollastonite to the glaze can fully reduce the thermal expansion and prevent the glaze from cracking after being exposed to air.
⑤ Application in electrical insulating materials
Wollastonite has high insulation rate when it forms non-conductive crystals, and it is a valuable material in high-quality power equipment. American companies add 20% wollastonite when making electric porcelain, which reduces the price of such products by 20 times. Insulating materials allow a very small amount of current to pass through, so wollastonite is used in radio ceramics, insulators with low dielectric loss, ceramic insulating foam of daily insulators, building insulating ceramics and other industries. Wollastonite is also especially suitable for UHF special electronic instruments, such as high-temperature ceramic components, high-voltage circuit breakers, phenolic adhesive resistors, and inorganic insulating materials with manufacturing temperature higher than 500℃.
⑥ In covered electrode industry.
Wollastonite is used in covered electrode coating to accelerate the melting speed, and has been used abroad for many years. Wollastonite used in covered electrode coating has the advantages of energy saving, porosity resistance, improved weld strength, smooth weld surface, improved droplet transfer and accelerated coating melting speed. In particular, our company's wollastonite has low impurity content and excellent quality, which is suitable for making special coated covered electrode and buried flux.
⑦ Wollastonite replaces short fiber asbestos and fiber talc.
Because people are easy to get cancer in the process of processing asbestos products, this has been recognized in developed countries such as the United States and Japan, and the use of asbestos and its products has been eliminated, and needle-like wollastonite has been put into industrial production instead of short fiber asbestos and glass fiber. The needle-like wollastonite produced by our company is an ideal raw material for processing needle-like wollastonite powder and has broad development prospects.
(8) Other purposes.
Wollastonite is used in papermaking, which is a very promising industry. According to the forecast of foreign experts, the prospective demand of wollastonite is 750,000 tons per year, of which the consumption of papermaking accounts for 40%.
B, because of its low loss on ignition, wollastonite becomes a natural glass raw material that hardly produces bubbles, and can reduce the melting temperature, shorten the melting time and save a lot of energy.
C, wollastonite used in the production of ceramic binders and grinding wheels will greatly improve the melting speed and high temperature impact resistance. Some are also used as binder fillers for fine grinding wheels.
D in the FRP industry, replacing the filler in the resin with wollastonite can greatly reduce the product cost.
E, wollastonite powder can be used as a multilayer coating for slag cement blocks.
F wollastonite can be used as the matrix product of asbestos cement.
Wollastonite is also used to bond ceramic products, laminated plastics, marking materials, matches, oil filter paper, plywood, artificial rubber, siding and so on.
H grinding tools, casting products, electrical equipment, walls between ships, metal products, enamel coatings, coatings on reinforced concrete blocks, white cement, brake structural gaskets, pressure vessels, grease, battery separators, etc. The application fields of wollastonite are all used for ceramic bonding abroad.