 KCC was purchased by Sohio in 1981 and the mine reopened in 1987 after BP Minerals purchased the assets.In 1989 the Rio Tinto Group acquired the asset, who modernized the mine, mill and smelter.The open-pit owners replaced an antiquated 1000-car railroad with conveyor belts and pipelines for transporting the ore and waste, which reduced costs by nearly 30% and returned the operation to profitability.