Definition of conditions of selective iron reduction from iron-manganese ore

Abstract

The article presents thermodynamic modeling results of reduction roasting of ferromanganese ore with a high phosphorus content in the presence of solid carbon. The modeling was carried out using TERRA software package. Influence of the process temperature in the range 950 – 1300 K and carbon content in the amount of 8.50 – 8.85 g per 100 g of ore on reduction of iron, manganese and phosphorus was investigated. With these parameters of the system, iron is reduced by both solid carbon and carbon monoxide CO to the metallic state, and manganese is reduced only to MnO oxide. The degree of phosphorus reduction depends on the amount of reducing agent. With an excess of carbon relative to the reduction of iron, all phosphorus is converted into metal at a temperature of 1150 K. Phosphorus is not reduced at temperatures below 1150 K and such amount of carbon. The process of solid-phase reduction of iron from manganese ore with the preservation of manganese in the oxide phase was researched in laboratory conditions. Experimental results of direct reduction of these elements with carbon and indirect reduction with carbon monoxide CO are presented. The experiments were carried out in the laboratory Tamman furnace at a temperature of 1000 – 1300 °C and holding time of 1 and 3 hours. Results of the research of phase composition of the reduction products, as well as chemical composition of the phases are considered. The possibility of selective solid-phase reduction of iron with solid carbon to the metallic state was confirmed. Iron in the studied conditions is reduced by carbon monoxide CO and passes into magnetic part. During the magnetic separation of the products of ore reduction roasting with solid carbon and carbon monoxide CO, the non-magnetic part contains oxides of manganese, silicon and calcium. The work results can be used in development of theoretical and technological foundations for the processing of ferromanganese ores, which are not processed by existing technologies.