Starting materials for production of solar grade silicon feedstock

摘要

There is provided a method of providing a first and a second starting material for a carbothermic reduction process, comprising the steps of:a) preparing a quartz product containing 0.5 ppm (w/w) or less boron and 1 ppm (w/w) or less phosphorus from natural quartz;b) providing part of said quartz product as the first starting material;c) reacting part of the quartz product with a carbon material, such as carbon black, containing 0.5 ppm (w/w) or less boron and 0.4 ppm (w/w) or less phosphorus to produce a silicon carbide product containing 1.5 ppm (w/w) or less boron and 3.0 ppm (w/w) or less phosphorus;d) providing said silicon carbide product as the second starting material.A agglomerated composition comprising the quartz product and the silicon carbide product is also provided.