NEW FLUX PRACTICE FOR THE UTILITY NICKEL FURNACES AT INCOS PORT-COLBORNE REFINERY

In the Utility Nickel furnaces, the hearth and sidewalls are lined wit h high-Al2O3 bricks. During charging and thermal cycling (more so as t he linings on these reverberatory furnaces age), pieces of brick spall or abrade from the refractory and collect on the top of the bath. The se pieces are removed using a non-corrosive slag to ward the end of th e heat when the bath temperature is approximately 1600-degrees-C. This benign liquid can be generated by two methods. First and most obvious , suitably ingredients can be pre-mixed so that the flux (flux A) is i sochemical with the non-corrosive slag. All that is needed to produce this targetted slag is heat. Second, in other proportions (flux B), th e pre-mixed ingredients generate a corrosive slag that melts completel y at approximately 1200-degrees-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 com position. Using this option, additions are monitored to avoid overflux ing. In both cases, the generated slag/brick mixture can then be rabbl ed from the furnace. This practice has been successfully used for over two years and has been a factor in extending Utility Nickel furnace l ife to its current levels (about 25% increase).