Why should calcium carbonate be surface modified

20/12/2021
|In Industry News
|By ALPA Powder

Surface modification is an important means necessary to improve the application performance of calcium carbonate, improve applicability, expand the market and consumption. In the future, functionalization and specialization will become the main trend of calcium carbonate development, and the market demand for various surface modification special calcium carbonate The amount will get bigger and bigger.

Why should calcium carbonate undergo surface modification?

Ultra-fineness is an important way to improve the quality of calcium carbonate, but the smaller the particle size of calcium carbonate, the higher the surface energy, the stronger the adsorption, and the more serious the agglomeration phenomenon.

Through surface modification, the modifier can be oriented to adsorb on the surface of calcium carbonate, so that the surface has charge characteristics. Due to the repulsion of the same kind of charge, calcium carbonate is not easy to agglomerate, thereby achieving good dispersion in the matrix.

Through surface modification, the interface compatibility and affinity between calcium carbonate and organisms can be increased, thereby improving its product performance with rubber or plastic composite materials.

Surface modification is an important means to reduce the oil absorption value of powder. After the surface modification of calcium carbonate, the aggregated particles are reduced, the degree of dispersion is improved, and the gap between the particles is reduced. At the same time, the coverage of the surface of the calcium carbonate by the modified molecules reduces the voids in the particles, and this coverage also changes the calcium carbonate. Its surface properties weaken its surface polarity, the friction between particles becomes smaller, and the lubricity becomes better, so the packing becomes tighter, the packing density increases, and the oil absorption value decreases.

Calcium carbonate without surface modification has poor compatibility, is easy to agglomerate, and has poor application effects, and these shortcomings become more obvious as the dosage increases.

Through surface modification, calcium carbonate has good interface affinity and reduced oil absorption. It can be better applied to high-end fields such as plastics, coatings, rubber, paper making, sealants, and breathable membranes to improve product quality and further reduce application companies’ Cost of production.

Calcium carbonate without surface modification can only be used as a traditional filling material, and its application field and dosage will be subject to certain restrictions. Through surface modification, calcium carbonate becomes a multifunctional modifier.

Calcium carbonate coated with silica on the surface can partially replace white carbon black and supplement the shortcomings of white carbon black in certain properties; light calcium carbonate coated with metal on the surface can improve certain special properties of rubber products; The calcium carbonate composite material coated with titanium dioxide can replace titanium dioxide to a certain extent; it can be treated with phosphate, aluminate, silicate or barium salt to prepare acid-resistant calcium carbonate.

At present, my country’s ordinary calcium carbonate has overcapacity, and competition for low-price products is fierce. After surface modification of calcium carbonate, the use effect is significantly improved, the user experience is good, and the product price naturally increases.

Calcium carbonate