Material composition and processing technology for quartz-kaolin rocks of the Khodzhakul deposit

Abstract

This paper describes the material composition and processing technology for quartz sand isolated from the quartz-kaolin rock of the Khodzhakul deposit group located in the Republic of Uzbekistan. The chemical, mineral, and grain-size compositions have been studied for the quartz-kaolin rocks and a processing technology has been developed for the resulting sand. Material composition of the sand was established by X-ray phase analysis after calcination at 900–1350 °C, as well as using chemical and IR spectroscopic analysis methods. The effect of dilution of the kaolin suspension isolated by decantation has been studied. According to the research results, the best processing values are observed when using Uniflok flocculant and sodium phosphate solution as the dispersant at a ratio of 1.0 : 1.0. An 8-EVSV-16/100 electromagnetic separator was used to study the additional processing of quartz sand in an electromagnetic field. Electromagnetic treatment of the quartz product allows removing up to 78.6 % of iron impurities. Based on the results obtained, a process flow was proposed for the extraction and separation of quartz sand from the original rocks and its additional processing. This process includes hydraulic extraction of the raw materials, primary classification in hydrocyclones, quartz flocculation and washing of kaolin slimes, drying of the quartz product, and dry electromagnetic separation using a roller separator. The process includes process water circulation. The quartz sand obtained using this technology contains 97.8 wt% of SiO2, less than 0.05 wt% of Fe2O3, and 1.20 wt% of Al2O3. The quartz product with the specified composition may be used for the manufacture of colorless transparent glass.