Laboratory investigation of valuable minerals concentration from poly-metallic wolfram-antimony ore deposit "osanica"

Abstract

This work presents the results of complex laboratory investigation carried out in order to determine the possibilities to produce quality concentrates of wolfram and antimony minerals out of polymetallic wolfram-antimony ore from Osanica deposit, near Petrovac na Mlavi in Serbia. Physical, chemical and mineralogical characterization of raw sample indicated that this is a high grade poly-metallic ore, having 1.67% of wolframite and 4.31% of antimonite. Besides valuable minerals, the presence of SiO2 is determined with the share of over 80% and occurrence of the iron minerals is predominantly in the form of pyrite. It is also found that surfaces of wolfram and antimony minerals are oxidized. Technological aspects of beneficiation included grinding tests as well as pre-concentration and concentration tests of wolfram minerals using combination of gravity, magnetic and flotation concentration methods. Bond index, established in grinding tests, accounted 14 kWh/t. Pre-concentration tests, performed on fraction -4+0 mm, did not give positive results due to high content of intergrowth valuable particles with gangue minerals. Results of gravitational and magnetic concentration, applied on fraction -0.5+0.1 mm, showed the possibility to produce wolframite type of the concentrate with over 60% WO3 and quality concentrate of antimony minerals with over 47% Sb. The main scope of this investigation was to evaluate the technological flowsheet of the preparation process for this specific ore, according to parameters that provide the best possible results for selective production of high quality concentrates of wolfram and antimony minerals.