Abstract: The present invention provides an apatite slurry in which secondary apatite particles are practically completely redispersed, and provides a method of manufacture therefor. The apatite slurry according to the present invention is characterized in that it comprises apatite particles which are dispersed in a water-compatible organic solvent and has a degree of dispersion such that the average particle size of the apatite particles is 1 .mu.m or less and particles of 3 .mu.m or more are practically absent. The method for manufacturing an apatite slurry according to the present invention is characterized in that an apatite slurry in which apatite particles are dispersed in a water-compatible organic solvent is fed to an agitation mill and reduced and dispersed until the degree of dispersion is such that particles of 3 .mu.m or more are practically absent.

Abstract: An air purifying agent comprising a carrier which contains short pulp fiber, on which one or more chemical components selected from the group consisting of acids, alkalis, oxidizing agents, reducing agents and antimicrobial components are supported. According to the present invention, an air purifying agent which is low in weight, is safe to handle and exhibits excellent effect in removing contaminated gases containing low concentrations of contaminants.

Abstract: An air purifying agent comprising a carbonaceous carrier and activated manganese dioxide and iodate supported thereon. According to the present invention, there can be provided an air purifying agent which is safe to handle and exhibits sufficient effect for removing contaminated gases.

Abstract: An additive for continuous casting of steel comprising as a base material a neutral to basic amorphous fluorine-containing calcium silicate containing up to 10% by weight R.sub.2 O.sub.3, wherein R represents Al and F, and up to 1.5% by weight P.sub.2 O.sub.5 ; this additive prevents surface defects on billets and final products derived therefrom in continuous casting.