Smelting and Refining

The Doe Run Company’s smelters are some of the largest and most productive facilities in the world, transforming mineral concentrates into usable metals and alloys. These products are used in radiation shielding, car batteries, TV screens and more.

Once lead concentrates are transported from the Doe Run mines to a smelter, they are sent through the sintering process, which uses a sinter machine to burn sulfur from the lead ore. The sinter is then conveyed into a blast furnace where it reaches molten-liquid form at approximately 3,000 degrees Fahrenheit, becoming lead bullion.

From the furnace, the bullion runs out of a tap hole, like a faucet, into a “settler.” The settler allows the lead, the heaviest of the bullion’s components, to settle before coming out a lead well and dropping into lead pots. An overhead crane then picks up the lead pots and transports the bullion to a dross kettle, where impurities (namely copper) are removed.

The bullion is pumped to a refinery, where undesirable minerals still remaining in the bullion, such as silver and zinc, are extracted. The result: products that are 99.99 percent pure.

During the smelting process, furnaces with temperatures of up to 3,000 degrees Fahrenheit are used to create lead bullion.