Producing a fired refractory silicon dioxide-rich lightweight refractory brick useful for thermal insulation of furnaces, comprises e.g. mixing a basic mixture of burnout materials and fine-grained refractory silica raw material

摘要

Producing a fired refractory silicon dioxide-rich lightweight refractory brick, comprises mixing a basic mixture of 60-80 wt.% burnout materials and 20-40 wt.% fine-grained refractory silica raw material or silica raw material mixture with respect to the basic mixture, 2-10 wt.% additional silicon dioxide rich lightweight filler or lightweight filler mixture, and 5-20 wt.% fibrous biogenic silica with addition of calcium oxide-containing binder, an organic pressing agent and water, pressing into brick moldings, drying, and burning at temperatures above 1200[deg] C. Producing a fired refractory silicon dioxide-rich lightweight refractory brick with greater than 80 wt. % silicon dioxide, a density less = 0.5 g/cm 3 and a classification temperature = 1300[deg] C on the basis of burnout materials, silicon dioxide rich lightweight fillers, fibrous biogenic silica and fine-grained silica raw materials, comprises mixing a basic mixture of 60-80 wt.%, preferably 65-75 wt.% burnout materials and 20-40 wt.%, preferably 25-35 wt.% fine-grained refractory silica raw material or silica raw material mixture with respect to the basic mixture, 2-10 wt.% additional silicon dioxide rich lightweight filler or lightweight filler mixture, which is melted during brick firing and 5-20 wt.%, preferably 7.5-15 wt.% fibrous biogenic silica with addition of calcium oxide-containing binder, an organic pressing agent and water, pressing into brick moldings, drying, and burning at temperatures above 1200[deg] C, preferably 1300-1500[deg] C.