Effects of additional fuel on the melting process in the Vanyukov furnace

Abstract

Due to the change in the composition of the processed raw materials at the Balkhash Copper Plant (BCP), it is required to adjust the technology used to melt copper sulfide concentrates in the Vanyukov furnace (VF). It is promising to use additional carbon-containing fuel that burns in the bubbling zone increasing the melting temperature and partially reducing slag oxides to ensure the required autogenousity and melting temperature. However, part of the solid fuel does not burn in the bubbling zone with an oxygen-containing blast and does not participate in reduction reactions with slag oxides that result in its accumulation on the surface of the slag melt. The results of the industrial tests performed earlier in the BCP to feed coal dust through tuyeres to the VF with the purpose to maintain the required temperature of the slag melt and satisfactory separation of slag and matte were considered. The reasons for the unstable operation of the tested system to feed coal dust to the VF through tuyeres were determined, and directions for its improvement were outlined. Laboratory experiments were performed to simulate the behavior of coal dust in the quiet zone of the VF. The regularities of the distribution of coal dust were determined, and it was shown that coal dust was concentrated on the slag melt surface. Thus, coal dust that did not react with blast oxygen or oxides of the slag melt in the bubbling zone was carried to the surface of the slag melt, promoted the formation of a viscous crust, and then practically did not interact with the slag melt and becomes practically useless.