Patent RU 2691344
A METHOD FOR CLEANING QUARTZ GRAINS AND QUARTZ GRAINS OBTAINED ACCORDING TO THE METHOD
(57) Summary:
The invention relates to the chemical, semiconductor and optical industries and can be used in the manufacture of quartz glass, optics, light guides. Quartz grains are processed in preheated to a temperature of at least 1000 °C the reactor in the presence of air by supplying hydrogen chloride gas into it. A rotating reactor with a horizontally oriented central axis is used, tilted at an angle of no more than 10 degrees. The flow of purified quartz grains is fed into the reactor continuously while they are being mixed. Hydrogen chloride is supplied through the unloading unit of purified quartz grains at a speed of at least 80 l/h with continuous forced removal of the resulting gaseous chlorination products at a speed of at least 2500 l/ h through the loading unit of the purified quartz grains. Purified quartz grains are obtained with the content of the following elements–impurities, ppb: iron - less than 100, sodium - less than 100, copper - less than 1, chromium - less than 1, nickel - less than 1, vanadium - less than 10, molybdenum - less than 10, cobalt - less than 10, manganese - less than 1. The invention makes it possible to obtain a finished product that meets the requirements of the semiconductor industry and the production of optical fibers in terms of purity, and to reduce the cleaning time of quartz grains.
