Processing of ilmenite through salt-water vapour roasting and leaching

The ilmenite fraction of beach sand has been processed through salt (NaCl, NaNO3 and Na2SO4)-water vapour roasting, followed by hydrochloric acid leaching. The optimum conditions for roasting are: 800 degrees C (885 degrees C for Na2SO4): 90 min (75 min for NaCl); ilmenite to salt (wt) ratio 1.70 for NaNO3, 2.00 for Na2SO4 and 0.67 for NaCl; N-2 flow rate 84 ml/cm(2) min; and water vapour pressure 0.042 bar. For the optimum leaching of ore, with a solid to liquid phase ratio (S/L) of 0.02 kg/l, a HCl concentration of 6 M (2 M for Na2SO4), a temperature of similar to 110 degrees C, and a pulp agitation speed of similar to 350 min(-1) are required. Under the above conditions 72.5%, 44.50% and 86.5% titanium and 96.0%, 55.9% and 71.0% iron are dissolved from ilmenite for NaCl, Na2SO4 and NaNO3 systems, respectively.