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Envirocon was contracted to provide selective dismantlement and asset recovery services at an aluminum smelter in Vancouver, Washington. The facility was used for aluminum reduction from 1940 through the late 1990s and additional production lines were installed in the 1960s. Envirocon was responsible for the safe and proper dismantling of the 650 reduction cells that made up the potlines at the Vancouver site. Each reduction cell or "pot” contained as much as 20 tons of recoverable ferrous and non-ferrous metals. The specific scope of work included:
- Removal and demolition of 650 aluminum reduction cells;
- Scrap decontamination, preparation, and sizing;
- Select structure cleaning; and
- Waste removal and loading into trucks for off-site disposal.
- Successful execution of the project required streamlined efficiency in dismantling and processing the cells and materials contained within them. Envirocon developed a comprehensive work plan that maximized the use of existing facilities and minimized travel distances between the required process areas enhancing safety and efficiency while reducing environmental liability. Envirocon added value by focusing efforts on waste segregation and minimization, seeking to manage all generated materials as potential assets.
Upon removal, each reduction cell was dismantled separating salvageable assets from waste materials. Salvageable assets consisted primarily of residual aluminum metal (metal left in pot when system was shut down, also known as “pads”) and steel. Aluminum pads were sized and stockpiled on site for sale by the client. Pot steel was also processed and sized for resale by the client. Some components of the reduction cell still required treatment for cyanide signature prior to being shipped off site as scrap. Envirocon provided this treatment as well as the loading of sized steel into shipping containers for overseas transportation to the consumer.
Items salvaged for recycling included 1,600,000 pounds of aluminum metal from “pot pads” and 12,000 tons of #1 heavy melt ferrous steel.
Waste materials consisted primarily of spent potliner (k088) and residual alumina, dust, and debris. Spent potliner was separated from the pot steel and then transported to an on-site containment building where it was stockpiled. Stockpiled potliner was then loaded into trucks which were brought inside the containment building. The material was transported to a Subtitle C landfill facility in Oregon. Dust and debris was hauled to a local Subtitle D landfill. Envirocon handled 9,600 tons of spent potliner 3,300 tons of dust and debris.
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