Improvement of technology and technique for the production of sinter at the SP EVRAZ KGOK. Report 2. The quality of the agglomerate from the mix heated by hot return

Abstract

A brief literature review of theoretical and applied works on the input of burnt lime into the sinter mix, experimental data on the effect of lime on the efficiency of granulation and heating of the mix, on the consumption of solid fuel, gas permeability and height of the mix bed, on the productivity of sinter machines and the strength of the sinter. The characteristics of the sinter plant of KGOK are given. Its main features are the operation of sinter machines for 100% finely milling concentrate coming from the processing plant through the mix preparation shop, heating the mix with hot returns to the “dew point” temperature, and maintaining a stable CaO content in the sinter, but not its basicity. The results of industrial studies of the effect of lime input, the granulometric composition of the concentrate and the basicity of the sinter on the productivity of sinter machines and the strength of the sinter are considered. It is shown that, in terms of its efficiency, the input of lime into the mix heated by hot return, is significantly inferior to the process of sinter mix without return heating. In particular, the mix is heated above the “dew point” temperature, which decrees its granulation and the positive effect on the gas permeability of the bed, the height of the mix bed and the strength of the sinter, as well as the productivity of sinter machines, decreases. It has been established that under these conditions, the consumption of lime is relatively effective not more 25 kg/t of concentrate. The dependences of the consumption of limestone and solid fuel on the rate of lime and the basicity of the sinter are presented. It is shown that the main factor determining the strength of the sinter is the granulometric composition of the concentrate and its stability, and additional factors are the basicity of the sinter and the bed height of the mix