초록 ▼

Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF4, by an alkali metal (Na preferred) is carried out by jetting a spray of reactants into a reaction chamber at a rate and temperature which causes the reaction to take place far en

Process for producing low cost, high purity solar grade Si wherein a reduction reaction, preferably the reduction of SiF4, by an alkali metal (Na preferred) is carried out by jetting a spray of reactants into a reaction chamber at a rate and temperature which causes the reaction to take place far enough away from the entry region to avoid plugging of reactants at the entry region and wherein separation in the melt is carried out continuously from the reaction and the Si can be cast directly from the melt.

대표청구항 ▼

A process for producing low cost, high purity, solar grade silicon by reaction of gaseous silicon tetrafluoride with sodium in substantially stoichiometric quantities to produce a reaction product consisting essentially of sodium fluoride and silicon from which silicon is recovered and wherein said

A process for producing low cost, high purity, solar grade silicon by reaction of gaseous silicon tetrafluoride with sodium in substantially stoichiometric quantities to produce a reaction product consisting essentially of sodium fluoride and silicon from which silicon is recovered and wherein said fluoride gas used in the reaction is obtained by thermal decomposition of sodium fluosilicate which is precipitated from aqueous fluosilicic acid generated from phosphate rock conversion to fertilizer, said process comprising: (a) carrying out said reaction inside a reactor including a reaction chamber formed with perforations in the walls thereof, said perforations being of a size such that essentially all of the molten sodium fluoride product of said reaction product freely passes out through the perforations due to the low surface tension of sodium fluoride compared to silicon, and molted silicon is preferentialy contained in the reaction chamber; (b) collecting said molten sodium fluoride product of said reaction product passing through said perforations in said reaction chamber in a sodium fluoride product collection and dispensing chamber surrounding said reaction chamber; and (c) removing the silicon product of said reaction product remaining in the lower portion of said reaction chamber by free flow.