Microcrystalline kaolinite has been rapidly synthesized in a specially designed pressure vessel rotated on rollers with grinding media. Starting material is sealed together with water and grinding media in a PTFE crucible covered by a stainless steel jacket, and heated and rotated in an oven with rollers. The synthesis process is hastened not only by temperature but also by continuous milling of the starting material and agitation of the reaction. The synthesis of kaolinite from weathered granite was studied in detail. Feldspathic granite powder, aluminum chloride solution and alumina beads were sealed in this vessel, and then rotated and heated for 2-8 days at 180°, 200° and 220°C under an autogenous vapor pressure. Yield of kaolinite increased with increases in temperature and duration time, and with decreases in the amount of granite. The duration time was shortened by approximately one-half of the stationary runs. Crystallite size of the produced kaolinite was smaller than that of stationary runs.
