RESEARCH INTO THE POSSIBILITY OF PROCESSING GRAPHITE-SHALE ROCKS TO OBTAIN GRAPHITE CONCENTRATE

Graphite is a popular material in the defense, steelmaking, mining industries, and is also used in microelectronics. The balance reserves of graphite in Russia are more than 100 million tons and are concentrated in large quantities in the Urals and Siberia. Natural graphite is associated with silicates and sulfides. The article presents a study of the processing of graphite-shale rock of the Far East. The material composition of graphite-shale rock is represented by silicon, iron, aluminum, calcium, sulfur, carbon, potassium and titanium. The rock is composed of shale, sulfides, carbonate minerals and graphite. The purpose of this work was to study the chemical and physical methods of enrichment of graphite-shale ores to obtain rough graphite concentrate. The objectives of the study were: determination of the material composition, study of acid and flotation separation of crude graphite concentrate, determination of the ash content of the original and obtained products, development of a process flow chart for processing graphite-shale ore. The following methods were used to solve the problems: Clever C-31 X-ray fluorescence spectrometer, ECS 80 series CHNS-O elemental analyzer according to the Dumas method, Levenhuk D95L LCD digital microscope, FMP-L1 flotation machine, EVS 15/5 separator. The original ore is represented by aggregates of isometric, acute-angled shapes, opaque in transmitted light. There is ore material in the form of pyrite. The average size of the aggregates is 95 μm. Acid decomposition of sulfuric or phosphoric acids does not allow obtaining crude concentrates. During acid decomposition, decomposition of sulfide and carbonate minerals and the transition of sesquioxides into solution are observed. During flotation enrichment, the extraction of graphite into the froth product was 75%, which exceeds the graphite content by more than four times compared to the original ore. During the second cleaning by flotation of rough graphite concentrate using diesel oil and polyethyleneglycol, a concentrate with a mass content of graphite of 21.76% was obtained. Magnetic separation of the original ore and enrichment products does not allow adequate separation of the magnetic fraction from the non-magnetic, due to the sulfide form of iron. The ash content of the original rock was determined to be 90.20% and of the rough graphite concentrate - 70.32%. Enrichment tailings are represented by silicates and sulfides. Enrichment waste is recommended to be used as raw material for the production of silicate materials.