National University of Science and Technology—NUST MISIS, Moscow, Russia:

Yushina T. I., Head of Department, Associate Professor, Candidate of Engineering Sciences, yushina.ti@misis.ru
Nguyen Van Trong, Trainee
Dumov A. M., Associate Professor, Candidate of Engineering Sciences
Nguyen Thu Thuy, Trainee

Sericite, an aluminosilicate group mineral, has a considerable economic value as it is used in many branches of industry, including the cosmetic industry, paint-and-varnish industry and in production of polymers. Vietnam possesses explored deposits holding commercial reserves of quartz–sericite ore. Producibility of marketable sericite concentrate was tested using quartz–sericite ore samples from the Ha Tinh Province. The data on the material constitution of the test ore from the X-ray structural analysis, optical studies and electron microscopy allowed offering a supposition on the feasible effective processing of the test ore by selective grinding and classification in hydraulic cyclones, which was experimentally proved. An essential loss of sericite in tailings required studying additional recovery of sericite by other methods. The studies into properties of cationic collector ArmacT by the Fourier Transform Infrared Spectroscopy (FTIR) to determine the nature of chemical bonds in molecules, as well as the adsorption tests of this collector at sericite and quartz in different operating conditions confirmed applicability of this agent to extract sericite from middlings (tailings of gravity concentration) and enabled flotation optimization. Based on the implemented studies and experimental processing of the test ore using selective grinding, classification in cyclones and flotation, the flow chart was developed for processing initial ore with the total mass fraction of SiO₂ 74.48%, Al₂O₃ 16.20%, K₂O 3.52%, Na₂O 0.59% with production of sericite concentrate with the average particle size of 10 μm and mass fractions of SiO2 49.33%; Al₂O₃ 34.56%; (K₂O+Na₂O) 9.12%. This product meets the quality standards imposed on the raw stock for various industries.

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