a method and apparatus of reclaiming hazardous inorganic wastes to produce an environmentally benign abrasive for use in loose grain processes , as a coated or bonded abrasive , or as a polishing grain . a tough and useful abrasive , with a moh hardness of 7 to 8 , is manufactured from emission control dusts of the aluminum industry or sludges from other industries , and may include small amounts of lead and cadmium oxides as toughening agents . the abrasive particles are sized by air sifting or by water sedimentation separating methods . the process for the manufacture of abrasive material comprises the steps of removing soluble salts from a waste stream by hot water extraction ; using a computer matrix to group the waste stream into different batches for mixing with other glass - making materials to form a batch mixture ; oxidizing the organic compounds contained in the batched mixture ; melting the batch mixture to form a glasseous substance ; and fritting the glasseous substance to form the abrasive . the process preferably uses a glass melter that will oxidize organics ; a scrubber to recapture vaporized heavy metal oxides and particles of the glass - making materials ; and an oxygen injection system ensure thorough burning of organics . certain sodium compounds may be added to reduce the melting point of the batch mixture . an abrasive formed by the process of the invention may comprise the following components by weight : 48 - 56 % silica ; 18 - 30 % alumina ; 6 - 12 % nao ; 6 - 12 % cao and mgo ; 2 - 4 % fe 2 o 3 ; and 0 . 1 - 1 % pbo .