Optimization of alkali metals discharge performance of blast furnace slag and its extreme value model

Abstract

In order to improve the alkali metals discharge capacity of slag, the gas-slag balance method was used to carry out the slag alkali metals discharge experiments, the effect of slag composition on alkali metals discharge performance of slag was studied, some suggestions were put forward to optimize the alkali metals discharge performance of slag and the extreme value model was established. The results show that the alkali metals discharge ratio of slag decreased with the increase in the binary basicity and mass fraction of TiO2, and increased with the increase in the mass fraction of MgO, Al2O3 and MnO. The change in slag composition led to the change in the solubility of alkali metal oxides in liquid slag, decomposition of alkali metal silicates, structure of the slag in liquid state and viscosity of the slag, and then affected the alkali metals discharge performance of slag. The ability of slag to absorb alkali metals was certain under the condition of fixed composition. With the help of slag alkali metals discharge extreme value model, whether the current slag meets the needs of blast furnace alkali metals discharge could be evaluated. The alkali metals discharge capacity of slag could be improved by optimizing the alkali metals discharge performance of slag combined with experiments and actual production.

Review of pellets and blast furnace slag research progress: the effects of MgO on metallurgical properties

“…The enrichment of K and Na increased to 3.37 and 0.56 kg/tHM, respectively. At the same time, the ability of alkali metals discharge ratio in the slag increases with the increasing MgO, which reduces the cyclic enrichment of alkali metals in the blast furnace [121].

Figure 17. Effect of MgO content on enrichment in slag [120].

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Erosion mechanism of harmful elements K and Zn on carbon brick in a 4000 m3 industrial blast furnace hearth

“…The presence of alkali and zinc metals in blast furnaces will affect many aspects of furnace operation, including ore expansion, iron softening, coke reactivity increase and coke degradation. [4][5][6][7][8] At present, some research studies on the erosion mechanism of harmful elements have been reported by some scholars. Jiao et al 9 believed that liquid potassium penetrated carbon bricks through pores and cracks, and then reacted with SiO 2 and Al 2 O 3 in the CO atmosphere.…”

“…The presence of alkali and zinc metals in blast furnaces will affect many aspects of furnace operation, including ore expansion, iron softening, coke reactivity increase and coke degradation. 4–8…”