Secondary materials

Metallic scrap is one significant source and can be pnrchased by the smelter or refinery at prices reflecting a nominal discount to the prevailing LME price for refined lead. However, the bulk of secondary lead is derived from the processing of recycled scrap lead-acid batteries. The trade is very localised with no general standard terms and the cost to the secondary smelter often simply reflects the cost of collection of scrap batteries. 

Terms are similarly structured to sulfide concentrates, with the exception that tfeatment charges will be negotiable given the individual smelter s capacity and ability to take additional secondary materials. Treatment charges are generally lower per tonne of material treated, but up to 50 per cent higher when expressed as per tonne of contained lead. There may also be additional penalties where high levels of particular impurities are present. 

Henley, K J, Radke, F and Tilyard, P A, 1998. Detemining the deportment of minor trace elements in base metal concentrates with examples from Broken Hill, in Proceedings The Mining Cycle - AusIMM Annual Conference, pp 381-388 (The Australasian Institute of Mining and Metallurgy Melbourne). 

Sutherland, K L and Wark, 1 W, 1955. Principles of Flotation (The Australasian Institute of Mining and Metallurgy Melbourne). 

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The initial step in the recycle of metals is the physical segregation of the metals from other materials. Eor new scrap this process is straightforward for old scrap it can be expensive. This classification and segregation of scrap is of importance to the producers of the metals from secondary materials. Historically, much of the classification has rehed on hand sorting which can be rehable, but it is labor intensive. The recycling of automotive scrap is illustrative of the... 

Ziac sulfate was made by 15 companies ia 1980 from secondary materials (93%) and from roasted ore, ie, ziac oxide (7%). The ziaciferous material reacts with sulfuric acid to form a solution, which is purified. After filtration, the solution is heated to evaporation and heptahydrate crystals are separated. It is sometimes sold ia this form but usually as the monohydrate [7446-19-7] which is made by dehydration at ca 100°C. Very pure ziac sulfate solution is made ia the manufacture of the pigment Hthopone [1345-05-7] ZnS-BaSO, and of ziac by electrowinning (see ZiNC AND ZINC ALLOYS). 

Asbestos composites To 1200 End properties vary widely depending on secondary material used. 

The extraction technology is applied for scrap recycling of tantalum and niobium and for the treatment of related materials. Recovery of tantalum and niobium from secondary material, such as Sn slag, Ti slag, W slag, catalyst wastes, used cemented carbide and used tantalum capacitors was reviewed by Dai, Zhong, Li and Li [483]. 

The primary phase of a substance into which a secondary material is embedded. 

For the most part, the zinc materials recovered from secondary materials such as slab zinc, alloys, dusts, and compounds are comparable in quality to primary products. Zinc in brass is the principal form of secondary recovery, although secondary slab zinc has risen substantially over the last few years because it has been the principal zinc product of electric arc furnace (EAF) dust recycling. Impure zinc oxide products and zinc-bearing slags are sometimes used as trace element additives in fertilizers and animal feeds. About 10% of the domestic requirement for zinc is satisfied by old scrap. 

Zinc fertilizers made from recycled hazardous secondary materials. U.S. EPA promulgated a conditional exclusion from the definition of solid waste for hazardous secondary materials that are recycled to make zinc fertilizers or zinc fertilizer ingredients. Zinc, an important micronutrient for plants and animals, can be removed from zinc-rich manufacturing residue and used to produce zinc micronutrient fertilizer. A second conditional exclusion applies to the zinc fertilizer products made from these secondary materials. 

Another LCI-related issue is allocation. This is especially relevant to waste treatment options when waste is recycled or used to generate energy, there is a multi-output process which needs to be dealt with. The waste then is no longer considered a waste, but a resource, and waste treatment is becoming a production process as well. What part of the emissions to allocate to the waste treatment service and what part to the secondary material or other co-product is then open to debate. ISO allows for various options. Whether additives are even visible in such processes is, again, doubtful. 

MATERIALS Explosive, thermate, blasting cap, and secondary material flour, cornstarch, powdered milk, cocoa, gasoline or other volatile fuel. 

The development and characterization of Certified Reference Materials is an expensive process. Because of this, emphasis on the use of Certified Reference Materials is usually directed more towards the initial validation of a method it is rarely economical to use a reference material for routine quality control although it can be used to calibrate other, cheaper, secondary materials which can be used for routine quality control. 

In this chapter, the effects and roles of secondary materials on platinum were investigated using electrochemically modified electrodes with ruthenimn, tin and molybdates. 

This predicted burn time of 1.3 minutes is most likely shorter than will actually occur. In reality, there will be additional time associated with the growth period of the fire and the pool fire may take minutes before reaching a steady-state burning rate. This time also does not account for secondary materials igniting and burning. 

The Resource Conservation and Recovery Act (RCRA) was enacted in 1976 and was revised substantially by the Hazardous and Solid Waste Amendment (HSWA) of 1984 (40 CFR pts. 260-280). The RCRA regulates the management of solid wastes that are hazardous. The definition of solid wastes in these regulations generally encompasses all discarded materials (including solid, liquid, semisolid, and contained gaseous materials) and many secondary materials (e.g., spent solvents, byproducts) that are recycled or reused rather than discarded [3]. Products such as commercial pesticides are not ordinarily solid wastes, but they become solid wastes if and when they are discarded or stored, treated, or transported prior to such disposal. 

The thermodynamic incompatibility of many of the solid phases present with each other as well as their local environment, results in formation of secondary minerals. Although the secondary materials may comprise only a small volume fraction of the waste, they (1) tend to increase in amount with time, as weathering processes proceed, (2) typically form at grain surfaces and are thus physically liable to react with percolating gas or liquids, and (3) may exhibit sites suitable for sorption or crystallo-chemical incorporation of trace elements (see Donahoe, 2004). Frequently observed secondary minerals include jarosite and ettringite the former is known to sorb ions such as Mn and As, whereas ettringite can form solid solutions, in which SO4 is replaced by Cr04 (Kumarathasan et al. 1990). 

It is useful to divide the analysis into mechanical and nonmechanical properties. We will first consider the wear resistance and compressive strength considerations, then see if potential materials will meet the aesthetic, bonding, and biocompatibility criteria. It may be possible to incorporate secondary materials such as colorants, bonding agents, and compatiblizers that address these issues. 

The materials to be tested ar e divided into two groups, one called the primary group and one called the secondary group. Each experiment will consist of one primary material plus a secondary material at some concentration. 

In the example shown, five primary, five secondary, and five concentrations were screened in twenty-five runs Five additional secondary materials with the same five primaries were then screened in a similar design ... 

Numbers in blocks indicate the concentration of the secondary material. 

If primary materials recovery is not practicable, then recover for a secondary material, or burn as a fuel if combushble. 

After release from fires, organic and some inorganic components undergo rapid or more delayed chemical transformation in the atmosphere. The physical properties as well as chemical composition of smoke particles may alter on the way from the source areas (biomass burning areas) to the measurement sites in Northern Europe. There are several reasons why particle properties change. Chemical components can, e.g., become oxidized or substituted in particles, but also the condensation of secondary material onto the LRT particles during the transport changes the particle properties. 

ARCILLA Ceramic Technology has centred on the utilisation of coal fly ash to create products for building and construction. New techniques have been developed to make use of many other secondary materials. A brief listing of products and systems ripe for commercialisation or poised to enter the market includes ... 

US Environmental Protection Agency (US EPA) (2002a) Zinc fertilizers made from recycled hazardous secondary materials. Federal Register, 67(142), 48393-415. 

Kosson, D.S., Van Der Sloot, H.A., Sanchez, F. and Garrabrants, A.C. (2002) An integrated framework for evaluating leaching in waste management and utilization of secondary materials. Environmental Engineering Science, 19(3), 159-204. 

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