Technological modeling of joint leaching of oily rolling scale and red mud

Abstract

From the analysis of data on beneficial use of red mud and oily mill scale, a new direction of recycling has been formulated: the joint processing of these wastes to produce liquid products. Technological modeling of the stage of joint water treatment of a mixture of red mud and oily mill scale was performed at an enlarged laboratory unit. The yields and compositions of the products were determined. A batch of washed sludge was sent for research on obtaining ironcontaining raw materials for subsequent pyrometallurgical processing. With component ratio of 1:1, solid to liquid ratio of 4, temperature of 95 °C and duration of 2 hours, 6.3 kg of the mixture were processed, 6.58 kg of washed precipitate with a moisture content of 21.3 % and 12.6 dm3 of the final solution were obtained. The specific volume of water evaporation was determined to be 31.3 dm3/h per 1 m2 of pulp surface. Compositions of the precipitate iron (54.4 %) and the final solution (1.1 – 1.3 mg/dm3) were established, which indicates an almost complete accumulation of iron in the precipitate. Concentrations in the products of processing impurities were determined: silicon, aluminum, phosphorus, sulfur, sodium oxide and organics. According to the results, a technological scheme for the joint processing of red mud and oily mill scale was developed and ways of using the process products were outlined: sludge – for iron, filtrate – for industrial treatment, evaporated and wash water – for leaching. Using the example of cooperation between enterprises of the Kamensk-Uralsky Industrial Unit, the hardware process diagram is considered. It is advisable to use the data obtained to implement the technology, in particular, to develop technological regulations for the design of a pilot installation.