Effect of particle size in the reduction of lateritic Ni ore in a Linder reactor

Abstract

Colombia possesses Nickel ore in the highlands of the San Jorge region, south of the department of Cordoba. The material extracted from the area is processed by means of calcination and fusion in a Rotary Kiln and an Electrical Arc Furnace EAF respectively to obtain the Ferronickel. During the crushing, drying, and calcination of the mineral within the Rotary Kiln, fine ore particles that contain Fe and Ni are produced; these fine particles must be agglomerated and then returned to the furnace for calcination. Inside the furnace, the size of the material and the velocity of the gases, limits the efficiency of the process, where particles less than 2 mm do not calcine and is expelled from the furnace. The present work analyses the influence of particle size of a lateritic mineral of nickel, submitted to reduction in a Linder reactor, using two particle size distributions; a conventional sample for reduction test and another fine. The materials were dried and then reduced at a temperature of 950°C, with coal as a reductive agent. It was found that the loss of mass due to the particle size was not relevant and the decrease of particle size improves the concentration of the desired material, optimizing the recuperation of Fe and Ni during the reduction stage.