METHOD OF PRODUCING ALUMINUM METAL AND POLYSILICON FROM MEDIUM CONTAINING SILICON AND ALUMINUM Russian patent published in 2024 - IPC C25C3/06 C25B1/00 

FIELD: aluminum metallurgy.

SUBSTANCE: invention relates to a method of producing aluminum metal and polysilicon from a medium with high content of silicon and aluminum. Method includes the following stages: step 1: pretreatment of a medium containing silicon and aluminum to obtain a material containing aluminum and silicon oxides; stage 2: electrolysis of molten salt is carried out in a double-chamber electrolytic cell using a material containing aluminum and silicon oxides, as initial material for electrolysis with production of aluminum metal and copper-aluminum-silicon alloy, wherein the two-chamber electrolytic cell is divided into an anode chamber and a cathode chamber for physical separation of the anode electrolyte from the cathode electrolyte, anode chamber is made containing anode, and cathode chamber is made containing cathode, copper-aluminum alloy is placed at the bottom of the two-chamber electrolytic cell and provided in contact with both the anode electrolyte and the cathode electrolyte, wherein the density of the anode current is from 0.1 to 1.5 A/cm², the temperature is from 800 to 1,000 °C, and under voltage conditions, the material containing aluminum and silicon oxides, fed into the anode chamber to form aluminum metal in the cathode chamber, and the copper-aluminum alloy at the bottom of the two-chamber electrolytic cell is converted to a copper-aluminum-silicon alloy; and step 3: extracting copper-aluminum-silicon alloy, placing it in a single-chamber electrolytic cell and performing electrolysis of molten salt to obtain polysilicon and/or aluminum-silicon alloy, wherein obtained aluminum-silicon alloy is used to obtain polysilicon by physical or chemical method, wherein the lower melt in the single-chamber electrolytic cell is an anode from a copper-aluminum-silicon alloy, the middle melt is a refining electrolyte, upper melt is a cathode from molten aluminum, anode current density is from 0.01 to 1.0 A/cm², temperature is from 800 to 1,100 °C, and under operating conditions under voltage Al and Si in copper-aluminum-silicon alloy are successively oxidised, transferred into refining electrolyte, then reduced on cathode from molten aluminum with production of polysilicon and/or aluminum-silicon alloy, wherein the aluminum-silicon alloy is used to obtain polysilicon by a physical or chemical method.

EFFECT: continuity of the process, as well as purification and removal of impurities in the process of producing aluminum metal and polysilicon.

10 cl, 3 dwg, 6 ex