Copper sources element concentration

Activation analysis is used to establish trace element gerprints of geologic deposits of native copper. By using the statistical techniques of discriminant analysis and K-means cluster analysis and the trace element concentrations in artifact copper, an assignment of probable geographic and(or) geologic source of the artifact raw material can be made. [Pg.273]

Rare eartb metals (REM), wbicb include tbe 15 lantbanoids as well as yttrium and scandium, tend to occur in tbe same ore deposits and exhibit similar chemical properties. The term rare earth is misleading because it implies scarcity and high costs as impediments for the use of these metals. Indeed, the element concentrations in the continental crust (Figure 6.1) show that even the rarest lanthanoid thulium is far more common than some precious metals, e.g. silver and gold, and the most abundant lanthanoid cerium is even more common than copper. However, because of their geochemical properties, rare earth elements have very little tendency to become concentrated in exploitable ore deposits. Consequently, most of the world s supply of REM comes from only a handful of sources. It was the very scarcity of these minerals (previously called "earths") that led to the term "rare earth". The REM are also considered as non-toxic and generally not expensive. [Pg.265]

Manufacture and Recovery. Electrolytic copper refinery slimes are the principal source of selenium and its sister element, tellurium, atomic numbers 34 and 52, respectively. Electrolytic copper refinery slimes are those constituents in the copper anode which are not solubilized during the refining process and ultimately accumulate in the bottom of the electrorefining tank. These slimes are periodically recovered and processed for their metal values. Slimes generated by the refining of primary copper, copper produced from ores and concentrates, generally contain from 5—25% selenium and 2—10% tellurium. [Pg.327]

FGD is used to control S02 emissions from coal and oil combustion from electric utilities and industrial sources. Impingement scrubbers are one wet scrubber configuration used to bring exhaust gases into contact with a sorbent designed to remove the S02. On occasion, wet scrubbers have been applied to S02 emissions from processes in the primary non-ferrous metals industries (e.g., copper, lead, and aluminum), but sulfuric acid or elemental sulfur plants are more popular control devices for controlling the high S02 concentrations associated with these processes. [Pg.232]

As some necessary meteorological data were unavailable, we employed two different techniques to estimate the element abundance in air. Reverse calculations, in the framework of the American program MEPAS, allowed us to find the concentration fields based on experimental and especially adapted meteorological data. The second technique included direct calculations in the framework of the Russian standardized program Ecologist, which took into account the actual chemical composition of copper-smelting production contaminants. Both techniques had some restrictions, mainly insufficient initial information on the sources of contaminants and limited possibilities of the analytical equipment used. [Pg.139]

In general, if there are no indoor sources of particles, the levels indoors tend to reflect those outdoors. For example, application of a mass balance model to measurements of indoor and outdoor particle concentrations in Riverside, California, indicated that 75% of PM2S and 65% of PMI0 in a typical home were from outdoors (Wallace, 1996). Similar conclusions were reached by Koutrakis et al. (1991, 1992) for homes in two counties in New York. For example, they report that 60% of the mass of particles in homes is due to outdoor sources. However, the contribution to various individual elements in the particles varies from 22% for copper to 100% for cadmium. [Pg.861]

As with copper, zinc is an essential element for all plants and animals. It is necessary for the correct function of various enzyme systems. However, excessive intakes of zinc can have long-term effects as they can interfere with absorption of copper and iron in the diet, and may result in anaemia.39 JECFA has recommended a PTDI of 1 mg/kg bodyweight, equivalent to 60 mg/day for a 60 kg adult.38 In food, the major contributors to the diet are meat and its products, from which zinc is readily absorbed. Liver, with concentrations of around 62 mg/kg, contains the highest levels of any meat products, with other tissues having values of a half to a third of this figure. The second greatest source of zinc is cereals. Concentrations of zinc in whole cereal products are similar to those in meat. [Pg.161]

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