Method for producing isolatable oxide microparticles or hydroxide microparticles

A method for producing isolatable oxide microparticles or hydroxide microparticles, wherein

• each of (I) a microparticle raw material solution which is obtained by mixing at least one microparticle raw material with a solvent, (II) a microparticle-separating solution, and (III) a microparticle-treating substance solution which is obtained by mixing at least one microparticle-treating substance with a solvent is prepared, wherein the method comprises:
• (IV) a step of separating oxide microparticles or hydroxide microparticles, wherein
• at least two fluids to be processed are used:
• out of them, at least one fluid is the fluid which contains the microparticle raw material solution and at least one fluid other than the microparticle raw material solution is the fluid which contains the microparticle-separating solution, wherein
• the fluid which contains the microparticle raw material solution is mixed with the fluid which contains the microparticle-separating solution in a thin film fluid formed between at least two processing surfaces which are disposed in a position they are faced with each other so as to be able to approach to and separate from each other, at least one of which rotates relative to the other, and
• (V) a step of mixing a fluid which contains the oxide microparticles or the hydroxide microparticles separated in the step (IV) with the fluid which contains the microparticle-treating substance solution, wherein
• the microparticle-treating substance is a substance which controls dispersibility of the said separated oxide maicroparticles or hydroxide microparticles.