A waste from coal mining was analyzed for chem. and phase compn. (SiO2 9-98% by mass, C 0.09-10%, Ca 0.01-8%, Fe 0.19-37%, K 0.1-0.4%, Na 0.1-0,3%, Cu 0.7-4%) and added to concrete (1:1 or 1:2 mass ratio). The product had compressive strength 33-47 MPa. The concretes produced under addn. of wastes from the prodn. of paving stones and granite processing showed substantially higher compressive strength.