The article is devoted to the processing of ash sludge generated during fuel oil combustion in the high-temperature zone of the boiler unit of the Murmansk TPP. It contains about 10% VO and 3% NiO, partly in water-soluble form. Improper disposal and storage of ash sludge can lead to contamination of soils and water basins of the region. To avoid this, such waste must be processed, which will not only reduce the environmental load, but also extract valuable components – vanadium and nickel. The behavior of vanadium and nickel during leaching of ash sludge with water and sulfuric acid solutions was studied and the need for oxidative roasting was established in order to increase the extraction of vanadium. The effect of the temperature of oxidative roasting and the amount of calcium or sodium carbonate additives on the extraction of VO was studied. The material compositions of the cinder after oxidative roasting and the residue from its leaching were determined. It is noted that oxidative roasting without additives does not lead to a significant increase in vanadium extraction, and nickel after roasting remains almost completely in the solid residue in the form of nickel ferrite. It was found that the use of CaCO additive allows extracting 76,0–78,9% of VO. Vanadium pentoxide with a purity of 94,4% was obtained from the resulting solution by precipitation.
Kashekov et al. (Wed,) studied this question.