Technique for reducing viscosity of illite containing kaolin

The invention relates to a technique for reducing the viscosity of illite containing kaolin, which comprises the following steps of : (1) purifying raw materials; (2) evenly mixing the kaolin and N-methyl pyrrolidone in proportion in a high-speed mixer and drying in an oven to obtain the premix; (3) mixing the premix and urea in proportion in the high-speed mixer, then moving to the oven for sealing and preserving the heat to obtain a mixture; and (4) dispersing the mixture in the high-speed mixer, adding composite dispersant and mixing to obtain kaolin with low viscosity. The method provided by the invention can reduce the viscosity of the illite containing kaolin effectively without the influence of the crystalline degree of kaolin and the mineral composition.