Electric Furnace Off-Gas Cleaning Systems Installation at PT Inco
PT Inco is a ferronickel smelter in Soroako, Sulawesi, Indonesia, which operates four electric smelting furnaces to smelt a ferronickel calcine prior to converting to nickel matte. The four electric furnaces operate continuously with calcine feed from five rotary kilns.
In 2003, WorleyParsons Gas Cleaning (formerly Gas Cleaning Technologies) performed a study to implement a new off-gas cleaning system on electric furnace #3 (EF3) at PT Inco. Proper combustion chamber design was critical to ensure complete combustion of the off-gas and to maximize combustion occurring within the furnace freeboard. Upon selection of a preferred combustion chamber and baghouse gas cleaning system design, the project was then carried through basic and detailed engineering in 2004. In 2005, the EF3 system was commissioned. The successful performance of the new system led to the design and implementation of similar systems on the other three electric furnaces. By the fall of 2007, all four electric furnaces had operating gas cleaning systems.
Prior to the start of the gas cleaning system project, off-gas from the furnaces exhausted directly to atmosphere via two chimneys without any gas cleaning. Today, all four furnaces operate with world-class emissions control. Furnace operation has also improved as a result of the optimum draft control provided by the off-gas systems.
This paper outlines the development of the project, key design considerations, and the results of implementing new gas cleaning systems on the four electric furnaces at PT Inco.