Abstract: Waste asbestos is converted into a glass by maintaining within an electrical glass melting furnace a body of molten glass at a temperature above the decomposition temperature of asbestos; supplying asbestos to the furnace; and withdrawing molten glass from the furnace at a temperature of at least 1000.degree. C. The asbestos is advantageously mixed with cullet and a melt accelerator and fed into the furnace by means of a screw mixer/conveyor. The furnace is advantageously operated at a pressure less than atmospheric pressure.

Abstract: This invention proposes a method of controlling the melting rate of a glass furnace to obtain substantially constant molten glass throughput. The furnace contains a pool of molten glass and a relatively thin layer of unmelted glass batch on the surface of the pool. The furnace contents are weighed, and the batch feed is controlled by the measured weight. In essence, the melting rate is determined by the thickness of the lighter, thermally insulated batch layer, since a thinner batch layer results in more heat loss through the batch and less batch melted by the cooler molten glass. Thus, a decrease in weight indicates more molten glass withdrawal and a lower melting rate, and batch is added to increase the molten glass temperature and to melt more glass batch. In the preferred embodiment, the furnace is electrically heated at a constant rate, and only the rate of batch feed is controlled to maintain substantially constant glass throughput.