1. Structure and Special Properties of Talc Powder in Liaoning Province

Talc powder is magnesium silicate hydrate. Its theoretical formula is 3MgO. 4SiO 2. H 2. It has a layered structure, divided into three layers, the middle is an octahedral MgO layer, the upper and lower are tetrahedral silica layer; talc powder in the two - OH base, therefore, its surface is hydrophobic. This is the reason why talc powder has special properties different from other pigments.

Application of Talc Powder in Paper Industry

Talc powder has its unique properties: layered structure: weak van der Waals force between layers of talc powder makes it easy to crack into thin layer during grinding; hydrophobicity (lipophilicity): low surface energy, organic matter is easy to adsorb to its layered surface. In the production of color paper, talc powder reduces dye consumption and effectively saves costs. In addition, its surface lipophilicity enables it to be used as resin and oleophile. Adhesive controllers and deinking agents for waste paper; Softness: smoothing and softening the coating surface, reducing the fracture of the coating and printing pressure; Lower friction factor: reducing the abrasion of the equipment (forming screen, scraper and printing press) and prolonging its service life; Chemical inertia: not reacting with any chemicals, not affected by any other additives, and has good performance with other paint components. Compatibility also means that it is insensitive to pH changes, and this chemical inertia also benefits the environment.

2. Talc powder as paper filler

In the early 1990s, the main technical significance of talc powder used in papermaking was still filler, accounting for about 60% of the total talc consumption in China.

Talc powder has high whiteness, high density and high refractive index. It has advantages as filler in paper industry: stable chemical properties, suitable for papermaking under acidic conditions, but also can be used with calcium carbonate in neutral conditions; its friction coefficient is small (lower than calcium carbonate), which can prolong the service life of papermaking network, and also suitable for high-speed paper machine; it is flaky particle, which is beneficial to storage in paper. Retain and improve paper opacity, smoothness and printing suitability; the surface is oily and can absorb organic matter. As filler, it also receives the effect of removing resin barrier, which is helpful for ink removal in waste paper deinking, which is incomparable with kaolin and calcium carbonate fillers; it can be well combined with sizing agent to improve sizing agent retention and reduce paper absorption. Sex, prevent printing ink from penetrating the paper.