US Patent 7833444 Fine particle granulation method

It is an object of the present invention to provide a fine particle granulation method capable of granulating fine particles in an extremely easy operation without the need for carrier particles that cannot be reliably isolated and removed or binders that remain as impurities, and of improving the handling properties of these fine particles, and of obtaining fine particles that can be rapidly broken down into primary particles during use. To achieve this object, the fine particle granulation method comprises an agitation step in which fine particles are dispersed in a supercritical fluid, and a spraying step in which the supercritical fluid with the fine particles dispersed therein is subjected to rapid adiabatic expansion.