Low-grade high-sulfur bauxite was pretreated via suspension roasting and muffle furnace roasting to remove sulfur and enhance digestion properties.
ETI Aluminyum A.Ş., the primary aluminium manufacturer of Turkey, is also one of the major integrated plants of the world capable of performing production from mining until end product. The alumina refinery was designed on a certain boehmitic bauxite quality basis. However, bauxite properties have changed over the years, …
Goethitic bauxite is a widely used raw material in the alumina industry. It is an essential prerequisite to clarify the effect of Ti- and Si-containing minerals on goethite transformation in the Bayer digestion process, which could efficiently utilize the Fe- and Al-containing minerals present in goethitic bauxite.
The leaching of iron oxides from boehmitic bauxite with hydrochloric acid has been investigated by means of optical microscopy, electron microscopy and electron microprobe analysis methods. Similar rectangular parallelepiped-shaped bauxite specimens were used for the leaching experiments.
The present research investigated the transformation rules of ( {text {S}}_ {2}^ { {2 - }}) in bauxite during roasting, and the impact of digestion conditions on the digestion efficiency of the roasted ore and ( {text {S}}_ {2}^ { {2 - }}) distribution. The study aims to provide a theoretical basis for the potential industrial use of large reserves …
In the Bayer process, the insoluble residue obtained after digestion of bauxite with sodium hydroxide at elevated temperature and pressure to extract alumina is known as red mud, or bauxite residue.
Kinetics model was developed for aluminum dissolution of West Kalimantan bauxite based on shrinking core model. A series of digestion tests was carried out to study aluminum dissolution from the ...
The digestion behavior of Australian gibbsite-boehmite bauxite and pure quartz in the Bayer process at 230–250 °C was systematically studied in this paper. The mineral composition and morphology of the reaction products were characterized and the kinetics of the quartz dissolution process was studied in detail.
Moreover, the relative digestion effi-ciency of alumina in roasted ore was about 3% higher than that in raw ore at a digestion temperature of 255 °C, suggesting that the roasting pre-treatment pro-moted the digestion of alumina in bauxite.
Alcoa World Alumina Australia operates two bauxite mines at Willowdale and Huntly in the Darling Range of southwestern Australia. Alcoa's aim after bauxite mining is to re-establish all the pre-existing land uses of the forest to as similar as the original forest as possible.
To process the bauxite, the bauxite must be mined, crushed, and delivered to the refinery. The first step to reaching the refinery after mining the bauxite is crushing. The crushing circuit is defined by a series of variables and how those variables come together to affect each other. Those variables include the following:
The Full Story. Minister of Science, Technology, Energy and Mining, Hon. Phillip Paulwell, foresees an inevitable cessation in the export of bauxite, noting that there are more long- term benefits in having it processed here in Jamaica. Addressing stakeholders, delegates and leaders of trade unions representing workers at the St. Ann …
Highly effective development and utilization of high-sulfur bauxite has an important practical significance to ensure a stable and secure supply of Chinese bauxite resources. Removal of sulfur is a crucial problem that needs to be addressed for the highly effective development and utilization of abundant high-sulfur bauxite resources.
Modeling the percentage of solids in bauxite mining tailings using geoprocessing. The average results for the yea r. 2021 indicated a max imum di fference. of 4.6% between laboratory data a nd ...
The use of innovative high-capacity, single-stream tube digestion technology reduces refinery complexity and improves energy efficiency. Tube digestion replaces the conventional shell-and-tube heat exchangers with jacketed pipe heaters. And, for some bauxites, it can also replace conventional digester vessels with pipe reactors.
With its history starting in the 1970s, the Company is the result of the merger of "Delphi Bauxites S.A." with "Greek Distomon Bauxites S.A.", and is today one of the two companies that are actively involved in bauxite mining in Greece.
The reductive Bayer digestion by using iron powder as reductant is proposed to convert hematite to magnetite and further to dissociate iron minerals from sodium aluminosilicate hydrate (desilication product, DSP) based on the differences of their surface properties. The results show that the differences of surface properties between magnetite …
A three-step sequential extraction was carried out by modified BCR approach for fractionation of metals, including rare earths in red mud. Acetic acid leaching, hydroxylamine hydrochloride + nitric acid leaching, hydrogen peroxide + acid ammonium acetate leaching, and orthophosphoric + nitric acid digestion in microwave were …
This suggests that zinc can react with high-valence sulfur to generate S 2− at digestion temperature, because digestion temperature of high-sulfur bauxite is higher than 513 K (240 °C) in ...
Jamaican bauxite is mainly gibbsitic but some amount of boehmite is also present. The average grade of bauxite mined is of the order of 45% available alumina and 1.5% reactive silica.
Mytilineos Energy & Metals on Tuesday announced the signing of an agreement with the French company Imerys for the acquisition of of the shares of Imerys Bauxites Greece Single Member Societe Anonyme for 10 million euros. The agreement concerns all bauxite mining activities in the Fokida area, which will now be …
Bauxite type and consequent digestion conditions may also imply in the dissolution of other minerals besides the aluminum (Al) sources. Adding to the particularities of each Bayer process circuits, fine auto-precipitated aluminum hydroxide and desilication products (DSP—commonly sodalite and cancrinite) are formed, resulting in different ...
Australian bauxite deposits have high grades and are shallow and relatively easy to mine. To learn more about the bauxite mining process go to our Bauxite Mining Chart. The quality of Australian bauxite means there are a number of small new mines either operating or in the exploration and approvals phase in Australia including:
To test this hypothesis, a set of digestion experiments were conducted using gibbsite, one of the major minerals in bauxite. Gibbsite was digested at various temperatures (50, 75, and 95 °C) in either 1 M or 6 M sodium hydroxide solutions for 30 min using either a convection oven or a 2.45 GHz microwave applicator.
Water is used to produce the steam required in the digestion process; in the preparation of aqueous caustic soda, flocculants and lime; to wash the ore, residues and recycled caustic and for dust mitigation. There are also uses such as vehicle washing, sanitation and provision of drinking water which occur at a refinery. The amount of water ...
The mercury varies with the geographical origin of bauxite ore [34] and, within a single deposit, mercury content can also vary significantly. To reliably ascertain the total mercury content bauxite ore and bauxite residue, a robust method was developed using microwave digestion and flow injection mercury system (FIMS) on the resulting solution.
The effect of lime on the pre-desilication and digestion of gibbsitic bauxite in synthetic sodium aluminate liquor at different temperatures was investigated. The bauxite is comprised of gibbsite, aluminogoethite, hematite, kaolin, quartz, and minor boehmite. Lime increases the desilication efficiency of the bauxite during the pre-desilication …
Bauxite residue is a mixture of several simple and complex oxides that are originated either from bauxite ore itself or from Bayer process as a by-product. Bauxite residue generally contains a large fraction of hematite …
In the 1960s, bauxite mining cleared 440ha of publicly-owned land in the Northern Jarrah Forest, but between 2010 and 2019, the figure had surged to 10,420ha – a nearly 25-fold increase. The report warns that if the current trend of bauxite mining continues, it could eventually clear up to 83,000ha of forest and fragment another …
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