STOP THE SMELTER!
We love our stuff and there is a trade off for loving our stuff. As consumers, we create demand on natural resources and many of those sources are metals harvested for aluminum production. Recycling is essential for the current consumer demands and as our primary resources are depleted, secondary aluminum smelter plants have been created. Primary Metals, from website http://www.ideals.illinoid.edu provides the following insight into aluminum processes and more specifically secondary aluminum process known as a smelter:
“Aluminum is primarily used to produce pistons, engine and body parts for cars, beverage cans, doors, siding and aluminum foil. It may also be used as sheet metal, aluminum plate and foil, rods, bars and wire, aircraft components, windows and door frames. The leading users of aluminum include the container and packaging industry, the transportation industry, and the building and construction industry.
Aluminum can either be produced from bauxite ore or from aluminum scrap. Refinement of aluminum ore is sufficiently expensive that the secondary production industry commands much of the market. About 40% of aluminum in the US is recovered for secondary refining (USEPA, 1995).
Due to high energy requirements, the major primary aluminum producers tend to locate in areas with low energy costs, including the Northwest and Ohio River Valley. Secondary producers tend to locate near industrial centers, including southern California and the Great Lakes.
Secondary Aluminum Production
In the secondary aluminum production industry, scrap aluminum is melted in gas- or oil-fired reverberatory or hearth furnaces. Impurities are removed using chlorine or other fluxes until the aluminum reaches the desired purity.
Other aluminum production plants use dross in addition to scrap. Dross is a by-product of primary aluminum melting. This process further reduces the pollution resulting from primary aluminum production. It contains fluxes and varying concentrations of aluminum. “Skim,” “rich,” or “white dross” refer to aluminum dross with high aluminum content. “Black dross” or “salt cakes” refer to aluminum dross from practices that use salt fluxes.
The dross is crushed, screened and melted in a rotary furnace where the molten aluminum is collected in the bottom. The resulting salt slag is a waste product. To reduce this waste more of the remaining metallics may be leached into water and collected.
To eliminate the need for salt fluxes, a new plasma torch treatment has been developed to heat the rotary furnace. High concentrations of aluminum are recovered from this procedure.
Pollution Prevention in Secondary Aluminum Processing
Air emissions and solid-phase wastes are the primary concerns in the aluminum processing industry. Air emissions depend largely on the quality of scrap used. Emissions can come from smelting, refining, and the furnace effluent gases. Gases can include combustion products, hydrogen chloride and metal chlorides, aluminum oxide metals and metal compounds. To reduce emissions regardless of the type of scrap used, aluminum fluoride can be substituted for chlorine to remove impurities from the molten metal. All systems are usually connected to emissions control equipment, typically a baghouse for collecting fluorine and other gases.
Solid-phase waste from secondary aluminum production is slag formed during smelting. The slag contains chlorides, fluxes and magnesium. The metallics may be separated and reused or sold.
Liquid wastes include water that is added to the slag to help separate the different metals. The waste water may be contaminated with salt and fluxes, but can often be recovered and reused. Both primary and secondary aluminum producers refine and melt the aluminum and pour it into bars called ingots. The ingots are shipped to metal casting plants or other shaping plants for molding or rolling. “
Important items to ponder.
If air emissions depend on the quality of scrapped used…is it even possible to know of the quality of scrapped used by Alliance Metals?
Liquid wastes contain toxic levels of metals and salts. How confident do you feel the waste water will not contaminate the ground and leach into our aquifer?
These processes generate dross also known as salt cake and due to its high metal content considered toxic.
How will this be handled, stored, transported?