US 12,110,232 B2
Method for producing technical silicon
Karl-Heinz Rimboeck, Heldenstein (DE); and Konrad Mautner, Burghausen (DE)
Assigned to WACKER CHEMIE AG, Munich (DE)
Appl. No. 17/598,412
Filed by WACKER CHEMIE AG, Munich (DE)
PCT Filed Mar. 27, 2019, PCT No. PCT/EP2019/057772
§ 371(c)(1), (2) Date Sep. 27, 2021,
PCT Pub. No. WO2020/192913, PCT Pub. Date Oct. 1, 2020.
Prior Publication US 2022/0162078 A1, May 26, 2022
Int. Cl. C01B 33/037 (2006.01)
CPC C01B 33/037 (2013.01) 17 Claims
 
1. A method for producing technical silicon, comprising:
heating a particulate raw material mixture comprising particulate silicon metal-containing material and a particulate mediator which comprises at least one of the elements C, O, Al, Ca and Si,
to at least 1490° C., forming a liquid silicon metal phase, and
solidifying the liquid silicon metal phase,
wherein the particulate raw material mixture is characterized by a characteristic number K,
K having a value of 0.000 to 60 mm and being calculated as follows:

OG Complex Work Unit Math
where
m(SiM) is the mass of the silicon metal-containing material
m(Med) is the mass of the mediator in the raw material
mixture
d50,SiM is the particle size (diameter) in mm at 50% of the mass undersize of the grading curve of the silicon metal-containing material,
d50,Med is the particle size (diameter) in mm at 50% of the mass undersize of the grading curve of the mediator, and
φ is the mean porosity of the silicon metal-containing material,
where the silicon-containing material is not subjected to further purification steps.