Scrap material

Reverberator Furnace. Using a reverberatory furnace, a fine particle feed can be used, the antimony content can be controlled, and batch operations can be carried out when the supply of scrap material is limited. However, the antimony-rich slags formed must be reduced in a blast furnace to recover the contained antimony and lead. For treating battery scrap, the reverberatory furnace serves as a large melting faciUty where the metallic components are hquefted and the oxides and sulfate in the filler material are concurrently reduced to lead metal and the antimony is oxidized. The furnace products are antimony-rich (5 to 9%) slag and low antimony (less than 1%) lead. 

Secondary. Scrap material, industrial and municipal wastes, and sludges containing mercury are treated in much the same manner as ores to recover mercury. Scrap products are first broken down to Hberate metallic mercury or its compounds. Heating in retorts vaporizes the mercury, which upon cooling condenses to high purity mercury metal. Industrial and municipal sludges and wastes may be treated chemically before roasting. 

A. J. Stone and P. H. Meyst, Ferrous Scrap Materials Manual ICRI Report No. 517, Iron Casting Research Institute (ICRI), Columbus, Ohio, Mar. 

The process provides fast mol ding cycles, unHmited shelf life for the sheet, large part capabQity, and design flexibOity. The process also allows for scrap materials to be recycled. Trim waste from the mol ding operation and defective parts can be ground up and recycled into the basic sheet process in controUed amounts. Some of this waste has also been used as input for injection mol ding. 

Transfer mol ding minimises preforming, and is usually used for the production of very small parts however, this technique may generate excessive amounts of scrap material. Flow requirements can be quite high, but fluorocarbon elastomers are available that are effective iu this appHcation. 

Through the development of such techniques as injection moulding it is possible to make highly complex parts in one operation without the need for assembly work or the generation of more than a notional amount of scrap material. 

Recycling The reuse of scrap material for pollution control and conservation purposes. 

Additional sources of the elements are tin slag and scrap. For instance, cassiterite deposits, in Australia, Brazil, Thailand and some other countries, contain a significant amount of tantalum. The bulk of this tantalum is collected in the slag and processed separately. Recycling of various tantalum-bearing scrap is also a veiy important source for tantalum production. These scrap materials include powder surplus from sintering operations, scrap from mill products, rejected and used capacitors, scrapped cutting tools and furnace hardware. 

Plutonium Scrap Processing. In addition to recovering plutonium from irradiated reactor fuel, a Plutonium Reclamation Facility (PRF)( 7,8) is operated at the Hanford site to recover, separate, and purTfy kilogram amounts of plutonium from a wide range of unirradiated scrap materials. A 20 percent TBP-CC1 k solution is used to extract Pu(IV) from HN03-HF-A1(N03)3 solutions of dissolved scrap. 

In addition to fuel and targets(15J6) from SRP reactors, SRP also reprocesses a wide variety of fuels from offsite research reactors and a wide range of unirradiated plutonium scrap materials.(17) Following customary Savannah River practice, initial processing of each offsite material is designed to transform the actinides to a solution that is compatible with one of the solvent extraction cycles in either of the separations areas. A major advantage of this practice is that the... 

As much as a quarter of a flexible foam block can be wasted in downstream processing into flnished products. Thanks to the efforts of process technologists and engineers, this scrap material can be recycled by at least 17 basic methods. However, only a few have found significant practical applications. Most other PU scrap ends up as uncollectable domestic waste with perhaps one key exception, materials from end-of-life vehicles. WESTERN EUROPE-GENERAL Accession no. 709465... 

Separation of ferrous and nonferrous metals, copper, and aluminum for separate recovery The scrap material and scrap metal dealers sort these metals (in part very finely) and send them to steelworks at home and abroad. 

In 1975, the total world tin production was 236,000 tons, of which 72% was produced by China (10%), Indonesia (8%), Malaysia (35%), Thailand (7%), and 6% each by the U.K. and the former Soviet Union (WHO 1980). Annual mine production of tin in the United States is a comparatively low 3300 metric tons (USPHS 1992). The world production of recycled tin was about 20,000 tons, of which France produced about half (WHO 1980). About 25% of the tin used in the United States is recovered from scrap materials containing tin. This secondary production occurs in the United States at 7 detinning plants and 162 processing plants (USPHS 1992). The production and consumption of tin chemicals, especially organotins, has increased markedly in the past several decades (Table 8.2). 

Deiringer, G Process for reclaiming thermally strained polyester scrap material, US Patent 5 225 130, Claim 12, 1991. 

You 11 recall that thermosets are polymAs that have lots of cross-linking. The molecules are three-dimensional, rather than two. More importantly, once the cross-linking bonds are in place, the polymer becomes rigid and hard. Put another way, once the thermoset occurs, it is irreversibly set. That s the difference between thermosets and thermoplastics. The latter can be remolded and reshaped the former cannot. When you sweep up the scrap material around the molding/extruding machines that handle thermosets, you throw it away. 

Aluminium alloys form one of the most widely used groups of materials in existence. They make products which are often cheap and can be applied to many different areas. Extensive work has been done on the experimental determination of binary and ternary phase diagrams, mainly during the mid-part of this century, and researchers such as Phillips (1961) and Mondolfo (1976) have produced detailed reviews of the literature which provide industry standard publications. However, although some important Al-alloys are based on ternary systems, such as the LM2S/ 356 casting alloy based on Al-Mg-Si, in practice they inevitably include small amounts of Cu, Mn, Fe, Ti etc., all of which can significantly modify the castability and properties of the final product. The situation is further exacerbated by the use of scrap material. It is therefore useful to be able to predict phase equilibria in multi-component alloys. 

Smaller quantities of metal are recovered from mercury-containing industrial and municipal wastes, such as amalgams and batteries. The scrap material is heated in a retort and the vapors of mercury are condensed into high-purity metal. 

Scrap value implies that the asset has no further useful life and is sold for the amount of scrap material in it. 

Solid-waste generation including off-spec product, scrap material, packaging, trash, etc. 

Induction furnaces offer certain advantages over electric arc or cupola furnaces. An induction furnace emits 75 percent less dust and fumes, due to the less turbulent nature of the heating employed inside the furnace. When coupled with the use of relatively clean scrap material, the need for emission control equipment may be avoided. For more information on induction furnaces, refer to USEPA (1985), and Danielson (1973). 

A predominant source of lead and cadmium in the emission control residuals from foundry melting operations is the scrap material itself. Materials such as coke and certain fluxes contain much lower quantities of trace metals than does the scrap. 

Because of their unique properties and in spite of their high initial cost, the platinum metals find many applications in industry. Since used platinum metals retain a large portion of their initial value, many scrap materials arc a major source of recoverable platinum metals. Practically every application of platinum generates scrap in some form, which is eventually returned to the platinum refiner for recycling. Although there are ample mine reserves, they soon would be depleted without constant scrap recycling. 

RECLAIMING. Recovery and reuse of scrap materials, either in low percentage in new product manufacture or in larger proportions in products in which the highest quality is nut essential. Among the materials widely reclaimed in industry are aluminum, steel, paper, rubber, glass, crankcase... 

Twenty-five percent of the tin used in the United States is recovered from scrap materials containing tin. This secondary production occurs in the eastern parts of the United States at 7 detinning plants and 162 processing plants (U.S. Bureau of Mines 1989). 

The U.S. Bureau of Mines (1989) estimated that the 1989 consumption of primary tin in the United States will be 39,000 metric tons, most of which will be met by imports and the domestic recovery of tin from scrap materials. 

Because the engineer thinks of depreciation as a measure of the decrease in value of property with time, depreciation can immediately be considered from a cost viewpoint. For example, suppose a piece of equipment had been put into use 10 years ago at a total cost of 31,000. The equipment is now worn out and is worth only 1000 as scrap material. The decrease in value during the lo-year period is 30,000 however, the engineer recognizes that this 30,000 is in reality a cost incurred for the use of the equipment. This depreciation cost was spread over a period of 10 years, and sound economic procedure would require part of this cost to be charged during each of the years. The application... 

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