Method for producing microparticles having controlled crystallite diameter

A method for producing a microparticle, wherein at least two fluids to be processed are used,

• of these at least one fluid to be processed is a raw material fluid containing at least one substance to be separated, and
• at least one fluid to be processed other than the foregoing fluid to be processed is a separating fluid containing at least one substance to separate the substance to be separated;
• these fluids to be processed are mixed 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, thereby separating the substance to be separated having a crystallite diameter thereof controlled;
• the crystallite diameter of the substance to be separated is controlled by changing specific conditions with regard to at least any one of the raw material fluid and the separating fluid that are introduced into between the at least two processing surfaces;
• the said specific conditions being at least two conditions selected from the group consisting of:
• kind of at least any one of at least one substance to be separated contained in the raw material fluid and at least one substance contained in the separating fluid,
• concentration of at least any one of at least one substance to be separated contained in the raw material fluid and at least one substance contained in the separating fluid,
• pH of at least any one of the raw material fluid and the separating fluid,
• introduction temperature of at least any one of the raw material fluid and the separating fluid, and
• introduction velocity of at least any one of the raw material fluid and the separating fluid.