Smelting of ores

The focus of this section is the emission of ultraviolet and visible radiation following thermal or electrical excitation of atoms. Atomic emission spectroscopy has a long history. Qualitative applications based on the color of flames were used in the smelting of ores as early as 1550 and were more fully developed around 1830 with the observation of atomic spectra generated by flame emission and spark emission.Quantitative applications based on the atomic emission from electrical sparks were developed by Norman Lockyer (1836-1920) in the early 1870s, and quantitative applications based on flame emission were pioneered by IT. G. Lunde-gardh in 1930. Atomic emission based on emission from a plasma was introduced in 1964. 

Relatively soon after ancient humans recognized the metals and their special properties, they also discovered ways to make alloys. Some alloys were produced in antiquity directly, by the smelting of ores that include two metals in their composition or mixtures of ores of different metals. Arsenical copper, bronze, and brass, for example, three alloys of copper... 

Arsenic (As) (can exist Cancer (skin and lung) Drinking water, smelting of ore,... 

Fluorite is used as a flux in steel making and in the smelting of ores. Luminescence sorting of fluorite is a well-known technique, which is based on the strong blue luminescence of Eu. ... 

Book Nine describes the various processes and machinery for the smelting of ores. Gold, silver, copper, iron, lead, tin, antimony, quicksilver and bismuth are included in these descriptions. 

Historically, slags have been an important by-product of the smelting of ores to produce metals. They serve the primary purpose of dissolving all of the extraneous rock into one homogeneous liquid from which the heavier metal reduced to its elemental state can separate by simple gravity segregation. They can also serve to absorb certain metal oxides while allowing another to be reduced to the elemental state. In some... 

Sulfur species are found in ambient air in most parts of North America and in most industrial countries. Their sources include natural emissions (biogenic and volcanic), smelting of ores and other industrial refining processes, and combustion of sulfurbearing fuels. This paper will focus on the combustion sources in the United States and some of the effects of their sulfur emissions. The environmental effects of sulfur in the environment have been of interest for many years and much of the information presented here has been drawn from the various conference proceedings and assessment documents that have been published in recent years (1-11). When specific references are not listed in the text, the information represents a consensus from these various sources. 

The history of zinc is interesting in that it was long used in the form of alloys before it came to be recognized as an element in 1746. For hundreds of years prior to that date, however, alloys of copper and zinc (brasses) were produced by the smelting of ores containing compounds... 

The analysis of metal artifacts has been used extensively to differentiate materials by sources. X-ray fluorescence and neutron activation analysis have both proved valuable in determining elemental concentrations. Native metals, such as gold, contained impurities that could, in some cases, be used to characterize their sources. However, the smelting of ores to recover the metals often changed the concentrations of impurities. Later, as alloys (e.g., bronze and brass) were produced, the compositions were intentionally altered and controlled. In some cases, the re-use of materials or the lack of quality control made the alloy composition quite variable (especially in terms of the trace components). 

The main introduction of arsenic into the biosphere is anthropogenic as result of industrial activity and the use of herbicides and biocides that contain the element. Arsenic is mainly released into the atmosphere as a consequence of its isolation, burning of fossil fuels and the smelting of ores (combustion). The oxides generated thermally are particulate in nature, which owing to their small size (in the nanometer scale) are held up in the exhaust gases and are easily vented into the local atmosphere and then distributed by the prevailing air currents. Models for the transport of arsenic predict that currently 285 tonnes are deposited annually on the Artie as a consequence of industrial activity in the northern hemisphere. 

Describe the process by which the copper that results from smelting of ore is purified by electrolysis. 

The results of Fig. 2.7 indicate that a significant fraction of particles in the nanometer size range will escape from electrostatic precipitator. for /i/oot values of the order of 10 ion sec cm . Such particles tend to form in high-temperature processes such as coal combustion, incineration, and the smelting of ores. Data are lacking on nanoparticle emissions from industrial electrostatic precipitators treating gases from coal-fired power plants or smelters. 

Characteristic colours of fumes (flames), as described by Agricola in 1550, were used to "control" the process of smelting of ores. Talbot (1826) and Wheatstone (1835) reported that the colours of flame and spark induced... 

Shaft furnaces had been used for several centuries for the smelting of ores and the burning of lime. Because of their high thermal efficiency and ease of operation they were the first, both in Sweden and the USA, to be adapted for iron ore pelletizing. In North America the first pilot plants were installed in Aurora and Babbitt, which started-up between 1948 and 1952. The first commercial plant was built for Erie Mining Co., Hoyt Lake, Mirmesota, beginning in 1954 and began operation in 1955. 

Steel making Smelting of ores, melting, annealing... 

Aggregate - concrete 11.3 Smelting of ores copper, lead, zinc. 

In the smelting of ores of metals such as copper and lead, sulfur dioxide (SO ) is produced. Because small amounts of selenium are mixed in with the sulfur, small amounts of selenium dioxide (SeO )... 

Usually refers to a substance used to clean surfaces and promote fusion in soldering. However, fluxes of various chemical natures are used in the smelting of ores in the ceramic industry, in assaying silver and gold ores, and in other endeavors. The most common fluxes are silica, various silicates, lime, sodium and potassium carbonate, and litharge and red lead in the ceramic industry. 

Smelter gas Produced in electric arc furnace during the smelting of ore with coal... 

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