Nikitin Gennadiy Mikhailovich

Abstract:

The process of melting ore mines in the ore-thermal furnace is gradual: softening, viscoplastic condition, melting. These forms depend on the composition of the ore and are defined in experimental laboratory conditions. To start the softening process, the mine shrinkage is taken at 10% (Ts), the end of shrinkage – 40% (Te). Viscoplastic condition is at a temperature range between the temperature of the end of shrinkage and the melting temperature of the ore (Tm), i.e.[1] What is interesting about this interval? – The ore mass turns into plastic condition and the porosity of the furnace disappears, i.e. there is no space for gas to pass. This barrier also occurs during the emission of melted furnace into the zone with low temperature: reducing reactions of oxides with carbon cause the formation of a plug for gas to come out. In open ore-thermal furnaces, the furnace man pokes with an iron pole – demolishes the viscoplastic zone. "Flaws" are formed in closed furnaces – gas breaks through the viscoplastic zone in its thin place (continuing reduction reactions in the space closed by the viscoplastic zone cause gas pressure to rise). In blast furnaces which produce iron-carbon alloys, there are special modes of charging a furnace by making "coke slots" through which gas comes out from viscoplastic zone.[2] The standard charging of a furnace in ore-thermal furnaces (ore-coke mixture) is not able to make "slots" for gas. However, it should be done. How? The supply of "idle rubbers" is necessary, i.e. the supply of coke separately from ore provides the opportunity of making "slots" for gas. Charging of "idle" supply is defined by time and gas pressure in ore-thermal furnaces. Bibliography 1. Nikitin G.M. etc. Detection of parameters of Viscoplastic Zone in Blast Furnace. Steel. 1992. #4, p. 11-16 2. Boranbaev B., Nikitin G., A. Mutti – Cayepcharging of Blast Furnaces. 2011. CSM Annual Melting Proceedings