Secondary Aluminum Smelters Research Articles

Inhalation exposure in secondary aluminium smelting

Inhalation exposure at seven UK secondary aluminium smelters was investigated to quantify the main exposures and identify their sources. The substances monitored were gases (carbon monoxide, hydrogen sulphide and nitrogen dioxide), total inhalable dust, metals, ammonia, polycyclic aromatic hydrocarbons (PAHs), particulate fluoride salts and acids. The results showed that people were exposed to a range of workplace air pollutants. Personal exposure results for total inhalable dust were between 700 and 5600 μg m−3 and the maximum personal exposure result for particulate fluoride salts was 690 μg m−3 (as F). The maximum aluminium, total PAH and lead personal exposure results were 900, 19 and 18 μg m−3 respectively. The average proportion of aluminium in total inhalable dust samples was 13% and rotary furnace processes generated the most dust. Particulate fluoride salt exposure was more widespread than hydrofluoric acid exposure. The source of the salt exposure was fluoride containing fluxes. The lead exposure source was lead solder contamination in the furnace charge.

Cancer morbidity in workers at aluminum foundries and secondary aluminum smelters.

In a Swedish cohort of workers (n = 6,454) from seven aluminum foundries and three secondary aluminum (scrap) smelters there was no overall excess risk of cancer among male or female workers less than 85 years of age (males: 325 observed cases, standardized incidence ratio (SIR) 1.02, 95% confidence interval (CI) 0.91-1.13; females: 22 cases, SIR = 0.95, 95% CI = 0.60-1.44). In male workers, however, significantly elevated risk estimates were observed for cancer of the lung (51 cases; SIR = 1.49, 95% CI = 1.11-1.96), anorectal cancer (33 cases; SIR 2.13, 95% CI = 1.47-2.99), and sinonasal cancer (4 cases; SIR = 4.70, 95% CI = 1.28-12.01). There was no increase of urinary bladder or liver cancer. Lung cancer risks were highest in workers with a short duration of employment (< 5 years) suggesting determinants of risk related to socioeconomic factors rather than the occupational environment under study, but there were also indications of a lung cancer hazard from sand casting of aluminum for 10 years or more (SIR = 2.10, 95% CI = 1.01-3.87). The increase in anorectal cancer could not be etiologically related to occupational determinants of risk. Sand casting of aluminum aside, the cancer risk in secondary aluminum smelting seems to be lower than in primary aluminum smelting and in iron and steel founding, respectively.

Hepatocellular carcinoma and exposure to hexachlorobenzene: a case report.

In the 1950s several thousand inhabitants of south eastern Turkey were affected by porphyria (por phyria turcica) caused by consuming wheat seeds treated with hexachlorobenzene (HCB) used as a fun gicide.13 HCB is a potent animal carcinogen causing thyroid and liver tumours in rodents.46 No report of cancer in man from exposure to HCB seems to have been published,7 but in view of the potential relation between porphyria and liver cancer,89 malignancy, particularly of this type, would attract interest in the context of exposure to HCB. Commercial production of HCB is reported to have ceased in the United States but HCB may still appear, for example, as a contaminant of various pesticides, as a byproduct in chlorinated hydrocarbon synthesis, and in municipal waste incineration.10 A recent con ference on HCB also reflects the worldwide interest and concern regarding this compound in the environ ment and its potentially adverse effects on man. The present report presents a case of hepatocellular carcinoma believed to be causally related to occupational exposure to HCB or possibly other chlorinated aromatic hydrocarbons, or both, created from hexachlorethane used in secondary aluminium smelting.

Compositions of Particles from Selected Sources in Philadelphia for Receptor Modeling Applications

As a part of a receptor model study of the Philadelphia, PA atmosphere, particulate samples were collected from seven air pollution sources in the area: two oil-fired power plants, a coal-fired power plant, a fluidized catalytic cracker, a refuse incinerator, a secondary aluminum smelter and an antimony ore roaster. Samples were collected in two size fractions with a dilution source sampler connected to a modified dichotomous sampler. Masses of collected material were determined gravimetrically. Samples were analyzed for elements by x-ray fluorescence followed by instrumental neutron activation analysis of some samples. Other samples were analyzed by chemical methods for volatile and nonvolatile carbon, SO/sub 4//sup 2/minus// and NH/sub 4//sup +/. Data are presented for up to 46 elements and species on fine (<2.5- ..mu..m aerodynamic equivalent diameter) and coarse (2.5 ..mu..m < diam < 7-10 ..mu..m) particles from each source. Although the data were collected for use in Philadelphia, they should be of value for receptor modeling of other areas having similar sources. The most unexpected results were the large amounts of rare earth elements on particles from the catalytic cracker and the oil-fired power plants. Substantial amounts of primary SO/sub 4//sup 2/minus// are released from the oil-fired plants, themore » SO/sub 4//sup 2/minus// concentrations accounting for 40-45 percent of the fine particulate mass.« less

Electrostatic separation of aluminum from dross

Aluminum dross makes up a substantial portion of a secondary aluminum smelter's total feed. However, fine dross (<10 mesh) is being discarded as industrial waste. This means a loss of millions of kilograms of aluminum metal each year potentially recoverable by a typical secondary smelter. The object of this study was to investigate the use of an electrostatic separator to recover the lost metal. After characterizing the dross constituents, a preliminary test on an electostatic separator resulted in a successful separation between metal and an oxide—salt phase. A commercial high tension separation unit was designed through factorial tests and a number of circuit configurations were developed. Using computer predictions and experimental simulations, a concentrate was produced that could be recirculated into the smelter profitably.

The present status of the Derham process for magnesium removal in secondary aluminium smelting

Magnesium is the only major contaminating element which can be removed chemically from an aluminium alloy melt in recycling operations. The most effective method used in the secondary aluminium industry to achieve this is to inject chlorine but the reaction results in unacceptable environmental and in-plant conditions unless strict control is maintained over the process. The Derham Process for ‘demagging’ aluminium melts also uses chlorine but has inbuilt safeguards against pollution as a result of the equipment design and the incorporation of a flux cover. This enhances the effectiveness of the operation over that of chlorination alone, by whatever means it is applied. Many additional benefits accrue through the use of the Derham Process in secondary aluminium smelting.