Aluminium industries

First manufacture of inorganic fluorides for aluminium industry... 

AIAG Neuhausen An electrolytic process for making aluminum from an all-fluoride melt. Developed by the Societe Suisse de F Aluminium Industrie at Neuhausen, Germany. 

Researchers in the aluminium industry have investigated the solubility of goethite in sodium aluminate and NaOH solutions. Basu (1983) found, using samples of natural goethite, that the equilibrium solubility of goethite in sodium aluminate solution was close to zero at room temperature and increased exponentially as the temperature rose above 100 °C. She also found that the isothermal solubility was greater in 5 M NaOH than in 5 M sodium aluminate solution at 150 °C, for example, [Fej] was 20 and 50 mgL , respectively. 

Today, a large number of important technologies are based on or related to electrodes reactions. Besides the chlor-alkali and aluminium industries, energy conversion in batteries and fuel cells, electrodeposition, electrorefining, organic electrosynthesis, industrial and biomedical sensors, corrosion and corrosion protection, etc. are amogst those technologies. In many of them, kinetic, catalytic or specificity aspects of electrode processes are of enormous importance. 

Aluminium Industrie AG, BritP 455761(1936) CA 31, 2578(I937)(Cartridge cases for military purposes made of Al-alloy which is coated with... 

HCB (Fig. 2) was used mainly as fungicide in wood and seed treatment, but it is also a by-product of several chlorination procedures for the production of organochlo-rine solvents, plastics and in the secondary aluminium industry (Fig. 3). A total... 

No wetting near the melting point due to the existence of an oxide layer on the surface at 900 °C 65° [468] at 1000 °C 126°[484] Extensively used in aluminium industry... 

Specific chemical exposures and exposure assessment methods relating to studies in the alumina and primary aluminium industry have been reviewed (14). In aluminium smelting, exposure to fluorides, coal tar pitch volatiles, and sulfur dioxide has tended to abate in recent years, but there is insufficient information about other exposures. Published epidemiological studies and quantitative exposure data for bauxite mining and alumina refining are virtually non-existent. Determination of possible exposure-response relations for this part of the industry through improved exposure assessment methods should be the focus of future studies. 

Benke G, Abramson M, Sim M. Exposures in the alumina and primary aluminium industry an historical review. Ann Occup Hyg 1998 42(3) 173-89. 

Using USA, Sweden and Norway as examples, the major known sources of PAH were residential combustion of wood, the aluminium industry, forest fires, coke manufacturing, oil fired intermediate commercial/industrial boilers, mobile sources and residential combustion of bitumious coal. 

FIGURE 4 The aggregated energy efficiency index for a number of countries. The sectors included are the iron and steel industry, the aluminium industry, the pulp and paper industry, the cement industry, and a major part of the chemical industry (the production of petrochemicals, ammonia, and chlorine). 

The determination of fluoride in air is very important in areas near aluminium industry. We have constructed an instrument using potentiometry with a fluoride selective electrode for continuous measurement of hydrogen fluoride in stack gases by absorbing them in a suitable... 

Traditionally, Zirpro -finished wool meets the above requirements and decabro-modiphenyl ether/antimony oxide-acrylic resin-fmished cotton fabrics (originally marketed as Caliban, White Chemical) have also been found to be suitable for workers in the aluminium industry. However, as discussed in Chapter 8, this latter finish is currently being withdrawn on environmental grounds and this whole area has recently been reviewed by Makinen, who lists more recent fabrics based on a variety of blends with flame retardant wool, viscose, and inherently flame retardant aramid fibres, for example. However, these factors are all different for molten iron or steel, copper, tin, lead, zinc, or aluminium and so protective aprons and overalls have to be tailored to fit the threat. Examples listed by Makinen for molten aluminium resistance include ... 

Theoretically, by poising the potential of an electrochemical cell at a value which is sufficient to reduce chromium(III) but not aluminium(III), chromium could be removed preferentially from solution. As chromium is a common contaminant of bauxitic alloys (the main feedstock for aluminium industry) electrochemistry may provide a means of selectively removing chromium from aluminium products. However, this process may be impractically slow. Much depends on the relative concentrations of aluminium and chromium, temperature, pH and cell design. Nevertheless, standard electrode potentials can be used as a preliminary evaluation of the feasibility of electrochemical methods for clean-up. 

All three fractions can be utilized. Starting at the smaller fractions, there is at first the condensate, which is accumulated in the flue gas control devices. Here, metals can be recovered and transferred to a base metal smelter. Chloride can be reused in aluminium industry or - as already practised - for chlor-alkali-electroly-sis, whereby chlorine is recycled. 

Pearson, T.G. (1955) The Chemical Background of the Aluminium Industry. Royal Institute of Chemistry, London. 

In the aluminium industry the most widely used method for the extraction of alumina (AI2O3) from bauxite is the Bayer process, in which aluminium and silica are leached from bauxite under pressure with hot caustic soda. The residue is red mud , a silt-like mixture of iron oxides, titanium dioxide, silica, caustic and many impurities. Roughly one ton of insoluble residue of red mud is produced for each ton of alumina. The liquors, following appropriate treatment to recover alumina, are recycled. In view of its high solubility in nature, it seems that most of the uranium must also be leached and possibly build up in the leach liquors. Small mills are now recovering this Uranium, but analyses of red muds show uranium contents that vary from 12 to 40ppm uranium, which suggest that it is not all leached. 

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