Material secondary raw

Secondary raw materials, or intermediates, are obtained from natural gas and crude oils through different processing schemes. The intermediates may be light hydrocarbon compounds such as methane and ethane, or heavier hydrocarbon mixtures such as naphtha or gas oil. Both naphtha and gas oil are crude oil fractions with different boiling ranges. The properties of these intermediates are discussed in Chapter 2. 

Natural gas and crude oils are the main sources for hydrocarbon intermediates or secondary raw materials for the production of petrochemicals. From natural gas, ethane and LPG are recovered for use as intermediates in the production of olefins and diolefms. Important chemicals such as methanol and ammonia are also based on methane via synthesis gas. On the other hand, refinery gases from different crude oil processing schemes are important sources for olefins and LPG. Crude oil distillates and residues are precursors for olefins and aromatics via cracking and reforming processes. This chapter reviews the properties of the different hydrocarbon intermediates—paraffins, olefins, diolefms, and aromatics. Petroleum fractions and residues as mixtures of different hydrocarbon classes and hydrocarbon derivatives are discussed separately at the end of the chapter. 

The method for the recovery of tantalum and niobium was developed for use on secondary raw materials in the form of oil-contaminated sludge. Uchino and Azuma [486] suggested using solid-liquid separation of oil from the slurry prior to the recovery of tantalum and niobium from the raw material. 

Materials recycling or resource recycling is essentially resource recovery, which is the means by which waste resources usually destined for disposal are used as secondary resources or secondary raw materials to serve as valued inputs to the economy, fulfilling both producer and consumer needs. Resource recycling, as has been pointed out, increases the supply of available material, and thereby offers a potentially attractive means of reducing... 

Secondary raw materials recovered from scrap are more concentrated and more pure than primary raw materials. Scrap is already in the metallic form, and requires only purification which, in the most favorable or desirable cases, involves only melting. The recovery of secondary metals can, therefore, be carried out with fewer and simpler operations, consuming a smaller amount of energy and causing less pollution, than primary metals production. For example, the production of 1 ton of copper from ore consumes about 116 GJ of energy, while the consumption is only about 19 G J when the production is from scrap. 

The utilisation of RCP as secondary raw material has to find a quantitative risk assessment in the future to establish meaningful limit values as basis for the development of e.g. elimination processes or barrier coatings. 

The UK Metals Industry REACH Group was founded in June 2005 to lobby for exclusion of metal ores and secondary raw materials from REACH and recognition of alloys as special preparations of metal covered by registrations of their components. 

Chapter 11 - In work the synthesis technology of zinccontaining polymer - inorganic composite on the basis of products of secondary raw material processing at joint precipitating with carbamide and formaldehyde (ZnCFO) is described. 

Despite of 150-year s history of vulcanization process, it is impossible to consider that fundamental and applied researches in direction of vulcanization systems perfection are completed. For today one of the ways of rubbers properties improvement is the synthesis and application of the new chemicals-additives, including, vulcanization active, that is connected, first of all, with reduction of global stocks of zinc ores as basic raw material for reception of traditional activator - zinc oxide. Besides, modem increase of industrial potential and the accumulation of big quantity wastes derivate the problems of ecological character, which require the emergency decision. Therefore creation of resourcesaving technologies of the new compounds reception from products of secondary raw material processing has paramount importance. 

The potential function of each chemical is also indicated PR = primary rawmaterial, SR = secondary raw material, I = intermediate, PF = primary final product, SF = secondary final product. 

The description of the workings of the control technologies is beyond the scope of this article. However, it is worth noting that many of these technologies create substantial amounts of solid or liquid waste that needs to be disposed of properly. For example, in the USA the total amount of fly ash produced from coal combustion alone is about 57 Mt/y (Kalyoncu 2000). About one-third is utilized as secondary raw material (e.g., for aggregate and asphalt), but the rest is usually disposed of in landfills. The wet and dry scrubbers for S02 control produce a sludge or dry waste that finds little secondary use, and a large amount is disposed in landfills. 

Unfortunately, the secondary residues (BA, FA, FC) of conventional MSW incinerators usually contain high metal concentrations as a consequence, they cannot be re-used as secondary raw materials. Air pollution control (APC) residues, which represent a mixture of FA and FC, must be treated prior to landfilling in order to reduce the leachability of heavy metals (ABB-EAWAG-EMPA-KEZO 1990 EKESA 1992 BUWAL 1998). Ideally, heavy metal concentrations could be made sufficiently low, so that MSW residues could be used without problems. In many European countries, leachability is the criterion by which a material might be selected for re-use. 

In addition, one may notice that, although most HT materials could not be disposed in landfills for inert materials on the basis of their content in trace metals, they all release very small concentrations of these metals during accelerated corrosion experiments, much below the permissible levels set by Swiss legislation. This demonstrates that HT materials pre-concentrate fairly large quantities of trace metals in their matrix, and they embed them over the long term when subjected to corrosion, whatever the technology developed to produce these materials on this basis, HT materials comply to the conditions required for safe secondary raw materials. 

From the lifetime cycle of a MSWI plant of about 30-40 years it is obvious that at least in the next two decades conventional MSWI BA will remain the dominant residue. In some European countries (e.g., The Netherlands, Germany, or France) legislation allows MSW BA to be used as secondary raw material, mainly for road construction. Some investigations proposed the use of MSW BA in concrete or other cementitious products (e.g., Targan et al. 2002) or as sintering promoters in porcelainized stoneware (Barbieri et al. 2002). 

The use of the BA as a potential secondary raw material such as cement additive has often been discussed (Pera et al. 1997 Pecqueur et al. 2001 Targan et al. 2002 Filipponi et al. 2003). The composition of the major oxides Al + Fe, Si and Ca of the BA is in the range of substitutes already in use, such as sewage sludge or coal fly ash (Fig. 5). However, as will be shown later, elevated heavy metal contents ate, from our... 

Incinerator waste as secondary raw material examples of applications in glasses, glass-ceramics and ceramics... 

Real balance yield BA is the ratio of the target product to the total amount of materials, including secondary raw materials (SRM) as solvents and catalysts, and given by ... 

The utilization of domestic natural nonrenewable resources is inevitable, and analyzing these resources helps to assess the profitability of importing raw materials, fuels, and semifinished products as well as utilizing secondary raw materials. In analyzing the exhaustion of nonrenewable natural resources, the balance equations of Eq. (5.20) should be modified if domestic nonrenewable resources are of interest. In this case, imported raw materials, fuels, and semifinished products should be taken into account separately... 

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