Kinetics of extraction of the silicon, aluminum, and calcium of the basalt from the Daubaba deposit

Abstract

The article presents the results of the experimental studies of the kinetics of electric smelting of the basalt from the Daubaba deposit, the main components of which are 50.5% SiO2, 19.9% Al2O3, 9.3% CaO, 9.6% Fe2O3 with the extraction of the silicon and aluminum into the ferroalloy, calcium into the calcium carbide. The effect of electric smelting time (from 10 to 60 minutes) and the amount of lime (from 0 to 30% from weight of basalt) on the degree of extraction of Si and Al into the alloy and Ca into CaC2 was determined. The studies were carried out by the method of planning the experiments with the usage of roto-standard plans of second order (Box-Hunter plan) with exploring graphic optimization of technological parameters. The electric smelting was carried out in a graphite crucible. The mass of the furnace-charge in each experiment was 400 g. It was found that: extraction of Si, Al into the alloy, and Ca into the calcium carbide becomes noticeable in the first 10 minutes of the process; in the absence of lime, the maximum degree of extraction of the silicon, aluminum in the alloy and the calcium, respectively, contain 80.8%, 72.2% and 69% in 45 minutes; the presence of lime in the furnace-charge allows you to increase the degree of extraction of the calcium in the calcium carbide to 79.8%, however, at this time, the extraction of the silicon and aluminum decreases. To extract 77.1-86.8% of the silicon, 75-82% of the aluminum in the alloy and 75-79% of the calcium in the calcium carbide, the duration of the electric smelting should be 46-50 minutes and the amount of lime to 6.1% from weight of basalt.