Prospects of Extracting Metals from Technogenic Wastes Using Concentrated Solar Radiation

According to a performed analysis, technogenic wastes produced by the JSC Almalyk Mining and Metallurgical Combine (Almalyk MMC) contain a total of 31 metals and elements, including iron (30.3 wt%), silicon (16.9 wt%), aluminum (4.7 wt%), etc. Experiments were carried out to further extract valuable components from such wastes involving their melting in a large solar furnace with a 1-MW thermal capacity. A method for smelting technogenic wastes having an average granularity of 74 μm in such a furnace was developed. The reduction smelting of a charge containing 5 kg of technogenic wastes, 0.5 kg of calcium oxide (10 wt% above 100%), and 0.25 kg (5 wt% above 100%) of coke was performed in a graphite crucible having a diameter of 250 mm and a height of 300 mm. The charged crucible was placed into the focal plane of a furnace and the process of charge smelting was performed under the action of a concentrated solar radiation flux with a density of 100 W/cm². The smelting charge in this furnace with the subsequent water quenching of the melt was shown to produce melt containing metals up to 22 wt%. A “small” solar furnace having a paraboloid concentrator of 12 m diameter and a focal plane of 30 cm diameter was calculated.