Studies for hydrometallurgical processing of titanium-magnesium production sludge with niobium extraction in solution

The material composition of sludge deposits from titanium-magnesium production was studied by chemical, X-ray, and microprobe analysis methods. Studies of the phase composition of the collector sludge showed that niobium is mainly bound with aluminum and titanium in oxide compounds. The particles of these compounds are very small and surrounded by the clay and carbonate component of the sludge collector. The chemical and mechanical activation processes of the sludge from the titanium-magnesium production sludge collector were executed based on the data obtained on the material composition. Alkaline leaching of sludge from sludge collector after preliminary activation was executed. The optimum conditions for the niobium extraction from the sludge of the sludge dump from the titanium-magnesium production were determined: sodium hydroxide concentration of 200 g/dm3, glycerol 5 g/dm3, S:L = 1:10, temperature 95 °C, leaching process duration - 4 hours. The addition of glycerol during alkaline leaching of sludge inhibits the transition of hexaniobate into insoluble sodium metaniobate enabling to increase the niobium extraction by 1.3 times with transfer into the solution of up to 80% of the extracted metal.