A study on the possibility of processing quartz-sericite ore of the Ha Tinh deposit in Vietnam

Abstract

Sericite has extensive applications due to its specific physicochemical and insulating properties. The total output of sericite products is currently around 350 thousand tons per year and tends to increase by 1–3 % annually. In the Vietnamese province of Ha Tinh, sericite is concentrated in several economic ore bodies. The results of X-ray diffraction, mineralogical, and petrographic analyzes have demonstrated that quartz, sericite, and potassium feldspar account for 97–99 % of the original ore volume. Mineral aggregates are mainly represented by closely intergrown microparticles. The results of process experiments have shown that high-grade sericite concentrates may be recovered from the ore by selective grinding and classification in hydrocyclones. In 20 μm separation, the sericite concentrate yield was 26.94 %, which is 7.48 % higher as compared to 10 μm separation (19.46 %). The concentrate grade, however, was somewhat reduced: the mass fraction of SiO2 in the –20 μm concentrate (52.44 %) was 2.83 % higher than that in the –10 μm concentrate (49.61 %) and the mass fraction of Al2O3 was 1.67 % lower in the –20 μm concentrate (32.76 %) than in the –10 μm concentrate (34.43 %). Selective flotation of –100+10 μm sericite middlings has confirmed the possibility of recovering granular sericite into a concentrate complying with the raw materials standards of a number of industries.