Pelletisation of reactant dosed laterite

Abstract

The present paperdeals with process parameters for pelletisation of laterite mixed with gypsum and coal in various proportions with a view to produce pellets for reduction smelting studies. Results are presented for pelletisation of laterite alone with various binders viz. bentonite, starch and sodium silicate. Bentonite and starch are found to enhance the strength of the pellets. It was observed that higher quantities of gypsum (as stoichiometrically required forcon¬verting various metal oxides available in laterite to sulphides) det-rimentally affect the pelletising characteristics of the mix. Various mixing methods were investigated. Pellets could be prepared by alternate charging of laterite coal mix and gypsum giving rise to a concentric layered arrangement of constituents. Premoisteningfol¬lowed by attrition mixing was found suitable for producing pellets with good physical properties. Addition of 6% moisture with attri¬tion mixing in a rod mill for 10 nits produced pellets of smooth spherical morphology with drop nos. 6-171p and air dried strength of more than 4 kg/p.