This paper investigates the results of preparative chemical activation and comminution of glass feedstocks prior to their melting in a furnace and also assesses the effects of this treatment on the productivity and energy efficiency of the furnace. The activation process consists of a hydrothermal treatment which makes it possible to break up the crystal structure of high-melting feedstocks and to ensure the beginning of the silicate formation process. Comparative tests for furnace productivity and efficiency are run against furnaces operating with untreated feeds. Results demonstrate that the preparative treatment has led to a 6-13 percent increase in the yield of molten glass, an productivity increase of 9-29 percent, and a reduction in gas consumption by the furnace of 7.4-10.5 percent.