refractory materials containing not less than 93 percent silica. They are made from silicic rocks, mainly quartzites, with an admixture of 2-2.5 percent lime. The crude rock is powdered and mixed with milk of lime; the articles are shaped on presses, dried, and fired at 1400°-1460°C. Dinas refractories are heat-resistant up to 1680°-1730°C. The temperature at which deformation begins under a 200-kilonewton/m2 (2 kg/cm2) load is 1630°-1670°C. The products are used in the construction of coke ovens and glass, open-hearth, and other furnaces. Special kinds of Dinas refractories have a higher silica content and higher density. Lightweight dinas refractory products with a density of 1.1-1.3 g/cm3 are also made.