Mn recovery from medium grade ore using a waste cellulosic reductant

Abstract

Medium grade siliceous manganese ore containing 38.22% Mn was leached in sulphuric acid medium using shredded newspaper as reducing agent. Objective of the present study was to investigate the effectiveness of ligno-cellulosic base wastes such as used newspaper as a reducing agent. The experimental parameters chosen for this study were: H(2)SO(4) concentration (2-5% v/v), temperature (60-90 degrees C), reductant to ore ratio (0.4-1) and ore particle size (57-274 mu m). Optimum conditions for >90% extraction were: 90 degrees C, 5% H(2)SO(4) (v/v), reductant to ore ratio 0.5, 8 h, 10% pulp density and ore particle size -100 mu m. Newspaper was found to be equally effective as a reducing agent for low grade ore (15.83% Mn) also wherein the amount of reductant and acid needed were proportional to Mn content of the ore. The leach solution was enriched to 87 g/L by recycling process. The enriched solution was purified by pH adjustment to 4.7 using 20% lime slurry. MnSO(4)center dot H(2)O was crystallized from purified solution. A schematic flow-Sheet has been included.