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Wollath is a calcareous metasilicate mineral with the chemical formula CaSiO3 or Ca3[Si3O9].
Among them, Ca is often plasmonized by Fe, Mg, Mn, Ti and Sr to form a homotopy, so pure wollastonite is rare in nature.
Wollath has three kinds of homogenous polyimage variants, which are the low-temperature trine, the low-temperature monocline and the high-temperature trine.
Wollastonite is divided into pae and pae.
The glassy grains are usually granular and powdery.
And the morphology is acicular and fibrous.
Wollastonite produced in nature is generally anamorphic, with fibrous, acicular or radial aggregates.
Wollastonite has the advantages of high brightness, low oil absorption rate, good electrical insulation and thermal resistance, stable chemical properties and high thermal stability.
I. application status
Fibrous wollastonite has a certain affinity with plant fiber, so it can partially replace pulp fiber, which not only saves raw materials but also has its unique advantages.
The advantages of fibrous wollastonite used in papermaking are: high whiteness, high opacity, no crystal water, low oil absorption, high resistance, low coefficient of thermal expansion, good heat resistance, corrosion resistance, weather resistance and mechanical properties.
Therefore wollastonite has been widely used in papermaking industry.
Fibrous wollastonite has high whiteness and refractive index, and can exhibit some fibrous properties.
Therefore wollastonite can replace the traditional filler used in newsprint, offset paper, writing paper and other cultural paper printing.
At present, many papermaking enterprises use deinking waste pulp to produce newsprint.
However, the whiteness of newsprint produced by deinking waste pulp is usually lower than 45%, which cannot reach the national standard of newsprint whiteness (48%).
So add some whiter fillers.
News pulp is mainly mechanical wood pulp and chemical mechanical wood pulp, a large amount of calcium carbonate, kaolin and other fillers will reduce the strength of newsprint.
The addition of wollastonite with fiber properties can effectively avoid this problem while meeting the requirement of increasing the whiteness of newsprint.
Meanwhile, lei jianmin et al. found that the refractive index of modified wollastonite was higher than that of pulp fiber.
Therefore, the addition of wollastonite can also improve the opacity of newsprint, and the degree of flatness and evenness of the paper has been greatly improved.
However, due to the lack of hydrogen bond between the paper filler and the pulp fiber, the addition of wollastonite also reduced the physical strength of the split length of the paper.
Wollastonite has properties similar to newsprint in offset printing paper.
It has the characteristics of increasing the whiteness and opacity of paper, improving the smoothness and evenness of paper, and reducing the breaking length of paper.
Wang jian et al. found that the ash content of offset printing paper after adding modified wollastonite was 2 times that of unmodified wollastonite lime.
This shows that the modified wollastonite has a high retention rate in offset printing paper.
And through the test of the printing adaptability of offset printing paper, it was found that the surface strength of offset printing paper was greatly improved after adding modified wollastonite.
Because fibrous wollastonite is a kind of mineral material with strong affinity with pulp fiber, it can be widely used in other cultural paper, and will not affect the strength of paper as seriously as other traditional mineral fillers.
And because of its good size stability, heat resistance, chemical resistance, flame retardant and electrical insulation plant fiber can not be compared with the characteristics, fibrous wollastonite in the pulp will give some special properties of paper, can be used in the production of special paper.
II. Several modified wollastonite
Xue honglong et al. modified wollastonite by acid and alkali two-step method. After modification, the particle size of wollastonite increased, and the whiteness was improved.
Sun chuanmin et al. found that modified wollastonite can greatly improve the whiteness, opacity and printability of recycled newsprint.
And because the modified wollastonite has good absorbency to ink particles, fine fibers and organic matter, the newsprint with modified wollastonite is easy to treat the waste water during the papermaking process, which is beneficial to the protection of forest and water.
Wang shumei et al. found that the average particle size of wollastonite modified by ultrasonic treatment decreased, the retention rate in paper decreased, and the paper strength and whiteness were improved.
After the inorganic modification of wollastonite, the retention rate in paper increased, paper strength increased;
The retention rate of wollastonite in paper after ultrasonic treatment and inorganic modification is more than 2 times that of unmodified ultrasonic.
At present, GuiLin HangDa Mining Machinery Co.,LTD.mainly has: HD series Raymond mill, HDH series ring roller Raymond mill, HDW series micro-Raymond mill, HDX series ultra-fine Raymond mill, HDD series multi-stage Raymond mill and so on.
The Raymond mill consists of main engine, analytical machine, blower, cyclone separator, pipeline device and motor.Stone powder processing equipment, stone powder mill adopts three-dimensional structure, covers a small area, complete set strong.
From the block to the finished powder independent into a production system.
And finished powder fineness uniform, through the sieve rate 99%, which is difficult to have other grinding equipment.
