Evaluation of Melting Temperature of the Freeze Slag in Reaction Shaft of Flash Smelting Furnace

摘要

According to the reaction shaft operation characteristics during the flash smelting process, 15 groups of slag samples containing high (Fe_3O_4) were prepared by some chemical reagents, and the slag melting temperatures were measured using a ZDHR-200 type intelligent test instrument for ash melting point by means of hemisphere point. Then, the mathematical formula between the melting temperature and the chemical composition of freeze slag were acquired by means of nonlinear regression analysis. The effects of the Fe/SiO_2 ratio (m_(Fe)/m_(SiO_2)), CaO/SiO_2 ratio (m_(Cao)/m_(SiO_2)), Fe_3O_4 content (w_(Fe_3O_4)), Cu_2O content (W_(Cu_2O)) and MgO content (w_(MgO)) on the slag melting temperature were also studied. Results show that the melting temperatures calculated by the regression formula reproduce the experimental data in molten freeze slag with high precision. The slag melting temperature ascends rapidly with increasing w_(Fe_3O_4) when w_(Fe_3O_4) >18%, and descends quickly when w_(Cu_2O) raises from 3% to 7%, but descends slowly with increasing w_(MgO). The melting temperature tend to go down first and then rise up with the increase of m_(Fe)/m_(SiO_2) and m_(Cao)/m_(SiO_2), arriving at the minimum when m_(Fe)/m_(SiO_2)=1.3 and m_(Cao)/m_(SiO_2)=0.8, respectively.