Contaminated scrap

Most metals in commercial use contain quite large quantities of impurity (e.g. as alloying elements, or in contaminated scrap). Solid-state transformations in impure metals are usually limited by the diffusion of these impurities through the bulk of the material. 

U.S. EPA, Contaminated Scrap Metal, U.S. Environmental Protection Agency, Washington, DC, July 2008. Available at http //www.epa.gov/rpdwebOO/source-reduction-management/scrapmetal.html... 

In 1997, the U.S. Department of Energy (DOE) released bench-scale results of an integrated TechXtract system for decontaminating surfaces contaminated with radionuclides. The overall economics of the system were evaluated. Costs for the system compared favorably with existing options for radioactively contaminated scrap metal (D177859, p. 3). 

Similarly, PBCDF agent-contaminated scrap metal that has been thermally decontaminated and further cleaned to remove loose residue may be managed as a hazardous waste and disposed of at a permitted RCRA TSDF or, alternatively, managed as scrap metal and recycled exclusively by smelting (ADEQ, 2006). 

Scrap-yards utilizing contaminated scrap from mines... 

Contaminated Scrap Contaminated, empty drums were shredded using a transportable metal shredder, packaged in cardboard boxes and fed into the incinerator via the solids feed system. The clean metal recovered from the ash discharge system was sold to a foundry and melted down into recyclable metal feedstock. Most of the scrap metal processing occurred during the warmer months. 

Mustard and contaminated scrap were incinerated out over a ten month period following approval of the test bums. During this time, the system availability averaged 55%, well below the industry average of 70 to 75% for solid waste incinerators. The prime cause was the need to perform frequent repairs to the refractory lining as a result of abrasion and impacts from the scrap metal feedstock. When operating, the system capably maintained stack emissions well within project limits and no stack excursions occurred while processing bulk mustard. 

The use of clean ferrous scrap (both steel and pig iron) will lead to increased purchase costs and will require investment in new cleaning equipment. There are no difficulties caused by scrap surface oxidation nor by using pig iron ingots during melting in cupola furnaces (reduction process). Electric furnaces will have difficulties only with contaminated scrap which does not comply with the parameters for steel scrap used in foundries. 

Prevention of waste water from scrap storage The generation of waste water from the storage of contaminated scrap can be prevented by roofing the storage area. The run-off water is collected as uncontaminated rainwater. All techniques for storage are discussed in Section 4.1... 

Selected ecoprofile information for production of PP resin and oriented PP film, packaged for shipment, is shown in Table 4.6. The film data is a weighted average of blown film and cast, tenter-frame oriented film. Production of the resin uses 73.66% of the total energy required (Fig. 4.14). Production of 1.2% contaminated scrap that must be disposed of is incorporated into the calculations [29]. 

Non-compactable drums hold radwaste like contaminated scrap iron or of similar stiffness. In the drums with filters are immobilized with cement used filters from the contaminated liquid circuits. 

The technology is based on the long-term experience gained at Siempelkamp s CARLA plant in Krefeid. This plant has been licensed per 3 of the German Radiation Protection Ordinance and used commercially since 1988. Up to now, more than 10,000 Mg of contaminated scrap from European nuclear installations have been melted and recycled in the nuclear field [1]. 

II) Single grades of contaminated plastic which can be collected from consumers or processors for example, used fertiliser sacks, crates, packaging materials and in-house contaminated scrap. 

Example D Recycling of Contaminated Scrap (Oxygen Lancing)... 

Melting contaminated scrap is a challenging task for an air-fuel combustion system. The metals recycling industry (e.g. aluminium, copper, lead) is forced to recycle even highly contaminated scrap to be competitive and protect the environment. 

Enhanced feedstock variations (contaminated scrap, low-grade scrap)... 

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