PRODUCTION OF CRUDE FERRONICKEL FROM SIVRIHISAR LATERITE ORES OF TURKEY

In the current work, laboratory-scale smelting experiments were conducted using Sivrihisar laterites (1.26% Ni). The ore samples previously subjected to drying, calcination and prereduction stages were smelted in alumina crucibles in a horizontal tube furnace under argon atmosphere. For the smelting system used in the present work, 1550 degrees C and 40 minutes were determined to be the optimum smelting temperature and time, respectively. 25% excess coal addition in prereduction stage was reported to be crucial to obtain the desired Ni content in the final product. Colemanite in calcined form has long been known as a flux used in pyrometallurgical systems such as steelmaking and copper matte-smelting. To investigate the effects of calcined colemanite addition on the ferronickel metal-slag system, calcined colemanite of 2% and 4% of the total metal and slag weight was charged as a flux and smelted under the optimum conditions described above.