The Hatch Furnace Group minimised the plant’s production losses with a record-setting furnace rebuild, complete with improvements to peripheral systems and safety. In 2012 these engineers were asked to fly into northern Brazil to investigate the Minera Onça Puma nickel facility when its smelting operations halted due to the failure of two furnaces (provided by another supplier). The facility is Vale’s first ferronickel operations in Brazil and one of the largest in the world. There were significant production losses, so timing was a major challenge.

The Hatch team quickly devised an action plan to rebuild furnace No.1 that involved maximum re-use of the existing equipment with parallel engineering and fabrication activities to minimise time. Hatch’s standard binding system design was adapted to include main elements of the existing crucible which required an innovative new spring-loaded system to provide the binding forces needed on the very large crucible and ensure furnace integrity during any thermal cycling and upset conditions.

While on site, the added opportunity was taken to improve overall plant safety by removing the existing water piping below the furnace and the open film water cooling from the lower sidewall—which could have been dangerous in the event of metal and slag leaks or run-outs.

The state-of-the-art Hatch monitoring and control system was installed to facilitate corrective action and protect furnace integrity during upset conditions and furnace shutdown. Other design improvements included replacing slag launders with proven Hatch Furnace Group water-cooled copper launders and redesigning the calcine transfer system.

All work was conducted in the plant’s limited space and completed in just over a year, as compared with three years for the original furnace—a world-record time for projects of this nature, Hatch claims. Many new procedures and designs were devised during the course of this project that will increase the efficiency and safety of smelter rebuilds in the future.