Optimization of carbothermal reduction of low-grade manganese ore utilizing microwave heating

Abstract

The upgrading of low-grade Egyptian manganese ore, utilizing microwave carbothermal reduction, was investigated. Standard ore-dressing methods were found fruitless because of the complex linkage of iron and manganese phases. Thermodynamic calculations showed the possibility of iron oxide selective reduction in the Fe-Mn-Si-O-C system. The current experiments indicated that the mixture of low-grade manganese ore and charcoal powders has good microwave heating ability, besides iron metal balls formation, which resulted in ore enrichment. The iron balls characterization indicates a high purity as they contain about 97 %iron. The results showed that the most significant factor affecting the degree of reduction was the experiment exposure time, followed by the charcoal ratio. The maximum reduction of 84.45 % was attained at a microwave exposure time of 7 min, a charcoal ratio of 1.0, and a basicity of 0.28.

Keywords

• Low-grade ore
• Carbothermal reduction
• Selective reduction
• Microwave heating