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Metals in the workplace
Published in Sue Reed, Dino Pisaniello, Geza Benke, Kerrie Burton, Principles of Occupational Health & Hygiene, 2020
Aluminium oxide is used as an abrasive, in refractory material and for electronic applications. The uses of aluminium are numerous: in automobile engines, shipbuilding, aircraft manufacture, home products such as doors, window frames, roofing and insulation, electrical wire and transmission cable, packaging material such as aluminium foil, drink cans and wrap, aluminium coatings for telescope mirrors, and decorative paper, packages and toys. Aluminium compounds and materials also have a wide variety of uses in the production of glass, ceramics, rubber, wood preservatives and pharmaceuticals, and in waterproofing textiles. Salts of aluminium include alum, which is used in water treatment, and natural aluminium minerals (e.g. bentonite and zeolite), which are used in water purification, sugar refining, brewing and the paper industry.
Metals in the workplace
Published in Sue Reed, Dino Pisaniello, Geza Benke, Principles of Occupational Health & Hygiene, 2020
Aluminium oxide is used as an abrasive, in refractory material and for electronic applications. The uses of aluminium are numerous: in automobile engines, transmissions, bodies and suspension components, shipbuilding, aircraft manufacture, home products such as doors, window frames, roofing and insulation, electrical wire and transmission cable, packaging material such as aluminium foil, drink cans and wrap, aluminium coatings for telescope mirrors, and decorative paper, packages and toys. Aluminium compounds and materials also have a wide variety of uses in the production of glass, ceramics, rubber, wood preservatives and pharmaceuticals, and in waterproofing textiles. Salts of aluminium include alum, which is used in water treatment, and natural aluminium minerals (e.g. bentonite and zeolite), which are used in water purification, sugar refining, brewing and the paper industry.
Gender in the Mining Industry
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Although it was not discovered until the 18th century, aluminium is the third most abundant element in the Earth’s crust. It is light weight but strong and ductile, with a low melting point and silver-white colour. It is highly reactive but difficult to extract from most of the minerals in which it occurs. Virtually all aluminium is extracted from bauxite, a lateritic ore containing gibbsite-a hydrated aluminium oxide. The process involves digestion in caustic soda followed by calcination to produce alumina; subsequently aluminium is obtained from the alumina by electrolytic reduction. Accordingly, production of aluminium is highly energy intensive. Aluminium is used in a variety of light weight alloys, particularly in transportation where light weight equates with reduced energy consumption, thus offsetting the energy used in its extraction. Aluminium compounds are widely used in water treatment, paper manufacture, in medicine and as refractory materials.
Preparation of industrial alumina from a biotite-rich kaolinite (BRK) ore by Cyanex®272
Published in Indian Chemical Engineer, 2021
Mustapha A. Raji, Alafara A. Baba, Lateef Ibrahim, Abdul G.F. Alabi, Malay K. Ghosh, Rafiu B. Bale
To date and with the rapid economic and population growth, the demand for pure aluminium and aluminium compounds of industrial value cannot be over emphasised especially in a wide array of uses in paper, refractories, adsorbents, catalysis, metallic aluminium, porous silica, pigment and alumina production [1–4]. One of the economic minerals that can be processed to serve the highlighted purposes is kaolin or kaolinite ore varieties including Biotite-rich kaolinite ore. In general, kaolinite (Al2Si2O5(OH)4) is a silicate mineral consisted of tetrahedral sheets (made up of Si and O atoms) and octahedral sheets (found to contain Al, O and OH) [5,6]. It is a layered mineral that can be attritive (through weak interactions) or functionalised (via grafting/covalent bonds) with organic molecules by either chemical or physical intercalation with the aid of different strategies [7]. However, the presence of red to yellow pigments observed in many kaolinite ore and its varieties are due to impurities associated such as oxides, hydroxides and hydrated oxides of ferric ion including hematite (red), goethite (brownish-yellow), ferrihydrite (brownish-red), etc. [8,9]. In order to obtain products of industrial grade, the potential enrichment of the mineral by removing the associated impurities become paramount.
Long-term corrosion behaviour of 1060 aluminium in deep-sea environment of South China Sea
Published in Corrosion Engineering, Science and Technology, 2021
Wenshan Peng, Tigang Duan, Jian Hou, Weimin Guo, Kangkang Ding, Wenhua Cheng, Likun Xu
The corrosion rate of the specimen exposed in the sea water with a depth of 3000 m is larger than that at other two depths. This is mainly owing to the change of the ionic radius and the degree of hydrolysis of metal ions caused by the increase of hydrostatic pressure [18]. The active of hydroxide ions (OH-) increases and the hydroxide ions in aqueous electrolytic solutions assist in passive layer formation. In addition, deep sea pressure promotes chloride adsorption. Dissociated chloride ions in sea water may penetrate this protective film and initiate crevice/pitting corrosion. As the water pressure increases, aluminium compounds, such as hydrated oxides and chlorides of aluminium, have higher reaction constant values [39], accelerate the destruction of the oxide film, and cause pitting and crevice corrosion.
Appraisal of suspended growth process for treatment of mixture of simulated petroleum, textile, domestic, agriculture and pharmaceutical wastewater
Published in Environmental Technology, 2020
Precious N. Egbuikwem, Iffat Naz, Devendra P. Saroj
After acclimation, phosphate uptake rate reduced to an average value of 74.3% and 76.6% at steady-state in reactors 1 and 2, respectively. The observed reduction was due to limited anaerobic conditions and build-up of phosphate in the treatment systems. These results disagreed with [14] who reported a 56% phosphate uptake in a complete aerated Modified Ludzack-Ettinger process under carbon-limited condition. The high phosphate removal in suspended growth system could follow different pathways. One of which is denitrifying phosphate accumulating organisms process [32,41] occurring inside the anaerobic zone of aerobic granules, though this process was limited due to limited anaerobic conditions and there were more of flocs than granules in the biomass. Another pathway for phosphorus removal is by calcium phosphate precipitation [43]. In the present study, phosphate may have been removed by calcium phosphate precipitation into the particulate matter thus contributing to the concentration of suspended particles measured in the treated effluent. This could be very possible as the trend dynamics of residual phosphate follow a similar pattern with that of suspended solids measured in terms of turbidity and TSS. Moreover, iron and aluminium compounds which were present in low concentration (EDX analysis: results not shown) may have contributed to phosphate precipitation in the aerobic treatment system [43]. Finally, organic sludge wasting may also be responsible for the observed reduction in phosphorus removal [43].