New flux practice for the Utility Nickel furnaces at Inco's Port Colborne Refinery

CIM Bulletin, Vol. 86, No. 971, 1993

C. Doyle, Inco Limited, J. Roy Gordon Research Laboratory, Sheridan Park, Mississauga, Ontario, A.E.M. Warner, D. Stremlaw and S. Harshaw, Inco Limited, Port Colborne, Ontario

In the Utility Nickel furnaces, the hearth and sidewalk are lined with high-Alf)3 bricks. During charging and thermal cycling (more so as the linings on these reverberatory furnaces age), pieces of brick spall or abrade from the refractory and collect on the top of the bath. These pieces are removed using a non-corrosive slag toward the end of the heat when the bath temperature is ~ 1600°C. This benign liquid can be generated by two methods. First and most obvious, suitable ingredients can be pre-mixed so that the flux (flux A) is isochemical with the non-corrosive slag. All that is needed to produce this target ted slag is heat. Second, in other proportions (flux B), the pre-mixed ingredients generate a corrosive slag that melts completely at ~ 1200°C and corrodes some but not all of the brick particles on the bath surface. As the reaction progresses, the slag changes composition eventually attaining the targetted benign composition. Using this option, additions are monitored to avoid overfluxing. In both cases, the generated slag/brick mixture can then be rabbled from the furnace. This practice has been successfully used for over two years and has been a factor in extending Utility Nickel furnace life to its current levels (about 25% increase).
Keywords: Furnaces, Nickel furnaces, Refineries, Utility Nickel furnaces.