Reducing effect of biomass derived char on iron ore fines; a statistical investigation and regression modelling

Abstract

India is an economically developing country. Country’s development and growth is largely interlinked with iron and steel industry as well as availability of energy and its utilization. Energy sector and iron and steel industry mainly consumes convectional and fossil fuel like coal and gas. Present coal reserves of India will last for about 30-40 years at present consumption rate. Consumption of conventional fuels is not economically feasible and environment friendly. Biomass can be an alternative source of fuel for numerous engineering and scientific applications. The char derived from biomass known as biochar can be utilized in the iron and steel-making processes. It can lessen the coke consumption rate and subsequently reduce pollution as well as cost economics. Utilization of low and lean grade iron ore is need of the hour. Removal of gangue impurities from lean and low-grade iron ore is difficult through convectional beneficiation process. The reduction roasting process can be adopted to counter these challenges. The present study focuses on the reduction behavior of iron ore using three various biochar derived from three biomass, viz; wood dust, sugarcane bagasse and coconut shell. A single factorial Design of Experiment with two levels and three variables was adopted and a first-order regression equation was generated to estimate the degree of reduction. The Student’s T-test and Fisher test were performed to validate the regression equation. The obtained results showed that the biochar can be used as a substitute reductant. However, the residence time and temperature play a vital role in the reduction process. The obtained regression equation also validates the effect of residence time and temperature on the reduction process.