Refining primary

AHoy scrap containing tin is handled by secondary smelters as part of their production of primary metals and alloys lead refineries accept solder, tin drosses, babbitt, and type metal. This type of scrap is remelted, impurities such as iron, copper, antimony, and zinc are removed, and the scrap is returned to the market as binary or ternary alloy. The dross obtained by cleaning up the scrap metal is returned to the primary refining process. 

Production operations are subject to a number of regulations, including those imposed by the Resource Conservation and Recovery Act (RCRA),6 7 the Clean Water Act (CWA),8 and the Clean Air Act (CAA).9 A number of RCRA-listed hazardous wastes are produced during primary refining operations that require the heating of ores to remove impurities. Specific pretreatment standards under the CWA apply to the processes associated with copper and aluminum. Lastly, large amounts... 

Distillation is a common method for the fractionation of petroleum that is used in the laboratory as well as in refineries. The technique of distillation has been practiced for many centuries, and the stills that have been employed have taken many forms (Speight, 1999). Distillation is the first and the most fundamental step in the refining process (after the crude oil has been cleaned and any remnants of brine removed) (Bland and Davidson, 1967 Speight, 1999, and references cited therein Speight and Ozum, 2002, and references cited therein), which is often referred to as the primary refining process. Distillation involves the separation of the various hydrocarbon compounds that occur naturally in a crude oil into a number of different fractions (a fraction is often referred to as a cut). 

The continued use of atmospheric and vacuum distillation has been a major part of refinery operations during this century and no doubt will continue to be employed, at least into the beginning of the twenty-first century, as the primary refining operation. 

The first and the most fundamental step in the refining process (after the crude oil has been cleaned and any remnants of brine removed) is distillation (Nelson, 1958 Bland and Davidson, 1967 Speight, 1999, and references cited therein Speight and Ozum, 2002, and references cited therein), which is often referred to as the primary refining process. 

Copper. For most antimonial alloys, this element does not have to be removed as alloys often specify the element. In calcium and soft-lead alloys, it is removed by the addition of sulfur (or iron pyrites/sulfur) to the bullion lead, as in the sulfur dressing process in primary refining. 

The world s first large refinery opened in Ploie ti, Romania, in 1856— 1857, with US investment. In the 19th century, refineries in the US processed crude oil primarily to recover the kerosene. There was no market for the more volatile fraction, including gasoline, which was considered waste and was often dumped directly into the nearest river. The invention of the automobile shifted the demand to gasoline and diesel, which remain the primary refined products today. 

While the Wohlwill type of process is still applied in small installations and for secondary refining, its large-scale use in primary refining has been superseded by other process routes which allow a smaller 1ockprocess involves chemical dissolution of gold as a chJoro-complex via CI2 bubbled through the liquor. 

The lead market is likely to remain intensely competitive. Metal demand, at best, will grow relatively slowly over the next few years. Although (primary) refined lead production may be somewhat constrained by raw material availability, and potential plant closures, metal supply (including stockpiled material, particularly in LME warehouses, and continued exports from the... 

In consequence, the scope for market entry by new primary refining companies seems limited, even as existing producers see their influence increase. At the same time, stagnating lead mine production and the closure of mature and marginal capacity will tend to raise concentration in the... 

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