(I) The use and quality requirements of talcum block

Block talc is divided into two categories according to the use, namely, industrial talc and cosmetic talc, each with corresponding quality requirements.

1. Industrial talc

According to the national standard BG1534-94, industrial talc according to the block length, width, thickness of any one of the largest size, divided into three specifications.

Large talc: the largest side of the size should be greater than 200mm; medium talc: the largest side of the size of 20 to 200mm; small talc: the largest particle size less than 20mm.

Small talc is subdivided into three quality levels: No. 1, No. 2 and No. 3. Industrial talc physical and chemical properties should be consistent with the provisions of Table 4.15.1. Block of talc used in the manufacture of talc porcelain, refractory bricks and electric plates, carving arts and crafts and filling in cosmetics, food.

2. Cosmetic talc Cosmetic grade block talc has high quality requirements, the physical and chemical properties have strict requirements. For example, no sandy particles in the ore, and there is a sense of lubrication. Total bacteria less than or equal to 500 / g, mold less than or equal to 100 / g, shall not be detected, such as Escherichia coli, staphylococcus, Pseudomonas aeruginosa and other pathogenic bacteria. The fineness is greater than or equal to 75μm when ground into talcum powder, and the passing rate is 98.0%. The heavy metal content is less than or equal to 40×10-4.

(B) Talcum powder use and technical and economic indicators

Talcum powder has a wide range of uses, the largest amount of paper industry, followed by the waterproof material industry.

1. Paper industry

Talc in the paper industry, there are three main uses, namely, as fillers, coatings and pulp resin control agent. Talc can make paper strong and white, increase opacity and brightness, and enhance the adsorption capacity of ink. Talc has a strong adhesion to pigments, so that color prints get good color effects. Talc's concave abrasion value is very low, so the paper making equipment and printing equipment wear and tear is very small. Moreover, talc density is less than titanium dioxide (TiO2), so as a filler than titanium dioxide superior. The price of talc is much lower than titanium dioxide, making it more competitive. Talc has been successfully used in waste paper deinking process, can effectively make the waste paper in the flotation and washing deinking.

2.Waterproof material

Talc can be used both as a filler for roofing products - linoleum, roofing paper, asphalt shingles, roofing panels, etc., and as an anti-sticking powder for roofing materials. When used as a filler, talc acts as a stabilizer in the molten asphalt component, increasing the stability and weathering resistance of the roofing material. When sprayed on the surface of asphalt shingles or rolled roofing materials, talc prevents them from sticking during production and storage. 
3.Other industries Talc has important uses in the plastics industry, rubber industry, cable industry, ceramics industry, paint industry and textile industry.