Prereduction of self-reducing pellets of manganese ore

Abstract

A brief review of alternative processes for production of high C Fe-Mn is presented. Experimental results of the reduction behaviour of charcoal bearing pellets with manganese concentrate at temperatures up to 1400uC are discussed. At temperatures up to 1000uC iron and manganese oxides are reduced to MnO, Fe and some Fe-Mn. At temperatures between 1000 and 1250uC, there is the formation of a liquid phase (Fe-Mn) by dissolution of reduced Mn into Fe. At temperatures between 1250 and 1350uC, manganese continues to be reduced and incorporated into Fe-Mn, and the composition of the metallic phase is similar to that of commercial Fe-Mn. The results have also shown that it is possible to obtain a Fe-Mn alloy with good recovery yield of Mn at temperatures within 1300 and 1400uC, without disintegration of the charcoal bearing pellet, but obtaining a liquid metallic phase inside it, favouring the coalescence of Fe-Mn. This result allows the prospect of new processes for Fe-Mn production with low energy consumption.

MnO reduction in high carbon ferromanganese production: practice and theory

“…Figure 7 illustrates decreased minimum required reduction temperatures due to the decreased activity of manganese in the alloy, from 1403°C at unit manganese activity, to 1312°C at 0.30 manganese activity. The effect of lowered manganese activity on the minimum required reduction temperature was well explained in a previous study (Braga et al, 2007). Figure 4(a), which consisted of carbon saturated alloy and also in the case of reduced ore particle surface contact with reductant particles.…”

Predicted effect of ore composition on slag formation in manganese ore reduction

“…This is in contrast with the situation in which lump ore or larger ore fines are used, where only the composition of the liquid slag phase formed upon bulk melting of the total furnace feed can be manipulated. As shown by Braga et al (2007) the use of composite pellets at 1400uC allows fast reduction of MnO to ferromanganese alloy before bulk melting of the agglomerate occurs which then results in a lower reduction rate.…”

“…Utilisation of ultra-fine ore and reductant in the form of self-reducing pellets has been reported by Braga et al (2007). Reduction occurs quickly inside the pellet at temperatures of 1250-1400uC, before bulk melting of the pellet occurs.…”

Simultaneous Selective Chlorination and Carbothermic Reduction of High-Iron Manganese Ore for the Recovery of Manganese Chloride and Metallic Iron

“…Cheap and high-grade manganese ores have become scarce due to its continuous consumption. Increasing attention has therefore been given to the development of technically and economically viable technologies for the utilization of medium-and low-grade manganese ores [10][11][12]. In addition, large quantities of manganese ore fines and tailings have been generated due to ineffective recovery technology and selective mining of high grade manganese ores [12][13][14], necessitating further treatment for metal recovery.…”