METHOD FOR PRODUCING MIXTURE OF SILICA AND CARBON

The invention provides a particle formed of silica and carbon which has a low impurities content and an excellent reactivity. In the particle formed of silica and carbon, the silica and carbon are each distributed throughout the particle interior, and the contents of boron (B) and phosphorus (P) are each 1 ppm or less. Also provided is a method of producing a silica and carbon-containing material which is an assembly of particles formed of silica and carbon, this method including: (B) a carbon mixing step of mixing an aqueous alkali silicate solution having a silicon (Si) concentration within the a liquid portion of at least 10 wt% with carbon so as to obtain a carbon-containing aqueous alkali silicate solution; and (C) a silica recovery step of mixing the carbon-containing aqueous alkali silicate solution obtained in the step (B) with a mineral acid so as to cause carbon (C) and silicon (Si) within the liquid portion to precipitate as particles formed of silica and carbon and thus obtaining a particle-containing liquid substance, then solid-liquid separating the particle-containing liquid substance so as to obtain a solid portion that contains a silica and carbon-containing material which is an assembly of particles formed of silica and carbon and a liquid portion that contains impurities.