Abstract:
The processing of ilmenite (TiFe03) to produce pigment grade while Ti02 and black Fe2 03 by various thermal, leaching and liquid-liquid extraction with subsequent precipilation treatments has been investigated. Thermal pre-treatment of ilmente with LPG-pyrolysed product at 7oo·c for 75 min- at LPG-flow rat.e 230 cm3 min-1 peoduces a roasted mass which gives ~83.5% titanium and 80% iron dissolutions in 6 g eq dm-3 hydrochloric acid at its boiling point, solid to liquid phase ratio (S/L) of 0.02 kg dm-3 and at
pulp agitaLion speed of 350 rpm for 5h. Under similar condition sulphuric acid diss0lves only 66% titanium o.nd 73% iron. X-ray powder diffraction patterns (XRD) of ilmenite and roasted muss suggest the chemicaJ/physical change occurring during roasting.
A different method of thermal treatment of ilmenite is to react with
the reformed products of the LPG-H20 vapour mixture in presence of nickel
catalyst. The optimum conditions for roasting are 700 ° C temperature, 110 cm3 min-1 LPG-flow rate, 0.041 atm. water vapour pressure and 40 min time. XRD shows the changes but the composition of roasted mass can not be identified. Hydrochloric acid gives better leaching results than sulphuric acid of identical concentration. About 93% titanium and 95% iron are
dissolv,•d in (i g eq dm-3 hydrochloric acid at its boiling point, S/JJ ratio of 0.02 kg dm-3 and at 350 rpm for 4h. Under simHar condition, only ~46% titanium and ~64% iron are dissolved in sulphuric acid. --------------
Description:
This Thesis is Submitted to the Department of Applied Chemistry and Chemical Engineering, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)
