TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The quartz product contains less than 300 ppm (wt./wt.) aluminum and/or less than 60 ppm (wt./wt.) iron. The sum of all metal impurities in the quartz product is less than 500 ppm (wt./wt.). The carbon material is carbon black derived from natural gas. The carbon material contains less than 5 ppm (wt./wt.) aluminum and/or less than 5 ppm (wt./wt.) iron. The first starting material for a carbothermic reduction process comprises: aluminum (Al) 300 ppm (wt./wt.) or 250-0.0001 ppt (wt./wt.) preferably 200 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), and boron (B) 0.5 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), preferably 0.4 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), 0.3 ppm (wt./wt.) to 0.0001 ppt (wt./wt.) or 0.35 ppm (wt./wt.) to 10 ppb (wt./wt.); and calcium (Ca) 20 ppm (wt./wt.), preferably 15-0.0001 ppt (wt./wt.), especially 10 ppm (wt./wt.) to 0.0001 ppt (wt./wt.); and optional gallium (Ga) 1 ppm, preferably 0.5 ppm to 0.0001 ppt (wt./wt.), especially 0.1 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), particularly 1 ppb (wt./wt.) to 0.0001 ppt (wt./wt.); nickel (Ni) 10 ppm (wt./wt.), preferably 5 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), especially 3.5 ppm to 0.0001 ppt (wt./wt.); phosphorus (P) 3 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), preferably 2 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), especially 1 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), and titan (Ti) 2 ppm (wt./wt.), preferably 1.7 ppm (wt./wt.) to 0.0001 ppt, especially 1.5 to 0.0001 ppt (wt./wt.); and zinc (Zn) 30 ppm (wt./wt.), preferably 25 ppm (wt./wt.) to 0.0001 ppt (wt./wt.) especially 10 ppm to 0.0001 ppt (wt./wt.). The second starting material for a carbothermic reduction process comprises: aluminum (Al) 30 ppm (wt./wt.) or 25 to 0.0001 ppt (wt./wt.), preferably 22 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), and boron (B) 1.5 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), preferably 1.0 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), especially 0.5 ppm (wt./wt.) to 0.0001 ppt (wt./wt.) or 0.35 ppm (wt./wt.) to 10 ppb (wt./wt.); and calcium (Ca) 20 ppm (wt./wt.), preferably 15 to 0.0001 ppt (wt./wt.), especially 10 ppm (wt./wt.) to 0.0001 ppt (wt./wt.); and optional gallium (Ga) 1 ppm, preferably 0.5 ppm to 0.0001 ppt (wt./wt.), especially 0.1 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), particularly 1 ppb (wt./wt.) to 0.0001 ppt (wt./wt.), nickel (Ni) 10 ppm (wt./wt.), preferably 5 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), especially 3.5 ppm to 0.0001 ppt (wt./wt.); phosphorus (P) 3 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), preferably 2 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), especially 1 ppm (wt./wt.) to 0.0001 ppt (wt./wt.), and titan (Ti) 2 ppm (wt./wt.), preferably 1.7 ppm (wt./wt.) to 0.0001 ppt, especially 1.5 to 0.0001 ppt (wt./wt.); and zinc (Zn) 30 ppm (wt./wt.), preferably 25 ppm (wt./wt.) to 0.0001 ppt (wt./wt.) especially 10 ppm to 0.0001 ppt (wt./wt.). Preferred Method: The step (a) involves at least one, such as at least two, three, four or five of crushing, milling, screening, optical sorting, magnet separation, gravimetric separation, flotation and/or acidic treatment of the natural quartz. The method further involves the provision of the carbon material and/or recycled silicon material, such as silicon kerfs or swarf, as additional starting material(s). The step (c) is performed in a furnace body, where the body comprises an inner lining, where inner the lining comprises: 80-95 wt./wt.% of a silicon carbide product containing less than or equal to 1.5 ppm wt./wt. boron and less than or equal to 3.0 ppm (wt./wt.) phosphorus; 5-20 wt./wt.% of a silicon product containing less than or equal to 1.5 ppm (wt./wt.) boron and less than or equal to 3.0 ppm (wt./wt.) phosphorus; and 0.1-5 wt./wt.% of a reaction product of a binding agent or a binding agent such as a resin e.g. a synthetic resin; and the reaction product of a binding agent, where the sum of the composition is 100 wt./wt.%. Preferred Composition: In the composition, the carbon/oxygen ratio by weight is less than or equal to 0.66. In the composition, the weight ratio of the quartz product to the silicon carbide product is 1.0-1.2:1.0. The agglomerated composition further comprises a binder, such as a carbohydrate, a resin, an alcohol or another hydrocarbon. In the agglomerated composition, the binder constitutes 1-10 wt./wt.% of the composition. The agglomerated composition further comprises 2-10 wt./wt.% of purified water; and 1-20 wt./wt.% of a silica fume. In the composition, the average diameter of the agglomerates is 2-20 mm. EXAMPLE - No suitable example given.