Dissolution of ilmenite by roasting with LPG-pyrolysed products and subsequent leaching

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Ilmenite has been leached with 6 g eq dm^-3hydrochloric and/or sulphuric acid after being roasted at (700±15)⁰C; with LPG flow rate of 230 cm³min^-1for 75 min at a partical size of 63-125 µm. The maximum weight percentages of metals dissolved from the roasted mass are ~ 85% titanium and 52.1% iron with 6 g eq dm^-3hydrochloric acid whereas it is 52.3% titanium and 60.8% iron with 6 g eq dm^-3sulphuric acid system. The optimum leaching with hydrochloric acid solution requires a higher acid concentration then 6 g eq dm^-3110⁰C temperature, solid to liquid phase ratio (S/L) of 0.02 kg dm^-3and a pulp agitation speed of 350 rpm for 5h. Identical concentration of sulpuric acid always gives poorer dissolution. Comparison of the X-ray powder diffraction patterns (XRD) of ilmenite and the roasted mass suggests certain chemical/physical changes occurring during treatment.</span>