The Effect of Pretreatment on Magnetic Separation of Ferruginous Minerals in Bauxite

Rao, R. Bhima; Besra, Laxmidhar; Reddy, B. S. R.; Banerjee, Goutam

doi:10.1155/1997/53574

Cited by 31 publications

(14 citation statements)

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“…The metal concentration was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS 7'500cx, Agilent Technologies, Basel, Switzerland). The following isotopes were analyzed: 27 Al, 45 Sc, 44 Ca, 47 Ti, 51 V, 53 Cr, 56 172 Yb and 175 Lu. The dwell time was set to 0.3 s per isotope and the argon plasma was operated at 1570 W with an argon flow of 15 L min −1 .…”

Section: Elemental Analysismentioning

confidence: 99%

Red mud as secondary source for critical raw materials – extraction study

Ujaczki

Zimmermann

Gasser

et al. 2017

J of Chemical Tech & Biotech

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BACKGROUND Red mud is a by‐product of alumina extraction from bauxite by the Bayer process produced in the billion tons scale worldwide. Red muds, or more generally bauxite residues, are regarded as waste, but may potentially be valuable sources of critical raw materials (CRM). In the present study both conventional extracting agents (mineral acids) and small molecular weight complexing agents (organic acids) were evaluated regarding their efficiency to extract CRM such as rare earth elements (REEs) from red mud. On a molar base, highest extraction efficiencies for REEs were achieved using HCl compared with the other acids investigated. Consequently, an experimental design approach was used to determine optimal conditions for CRM extraction using HCl. Instead of maximizing the extraction of a number of selected metals, the maximum economic potential as the sum of all metals (total metal extracted × economic value of the respective metal) was chosen as the application relevant response variable. Four explanatory variables (i.e. HCl concentration, contact time, temperature and slurry concentration) were used. RESULTS Optimal conditions maximizing the economic potential were predicted for 5.98 mol L−1 HCl, 21 h contact time, 50°C, and 56.7 g L−1 slurry concentration. Indeed, experimentally determined economic potential corresponded well (71% of predicted) with the predictions, allowing a maximum recovery of 297.6 US $ t−1. CONCLUSION Though the studied red muds were relatively low in CRM concentrations, the systematic approach developed here allows straightforward transfer to other red muds, harnessing the potential of the latter as important secondary source for CRM. © 2017 Society of Chemical Industry

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Section: Elemental Analysismentioning

confidence: 99%

Red mud as secondary source for critical raw materials – extraction study

Ujaczki

Zimmermann

Gasser

et al. 2017

J of Chemical Tech & Biotech

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“…Many studies have been conducted to separate iron constituents from the iron-rich bauxite by using physical methods [3,11], pyro-and hydro-metallurgical processes [5,[12][13][14], and bio-leaching methods [4,15]. Generally, it is difficult to achieve the sufficient separation of iron due to the complex occurrences and associations of disseminated iron-, aluminum-, and silicon-bearing minerals.…”

Section: Introductionmentioning

confidence: 99%

Digestion of Alumina from Non-Magnetic Material Obtained from Magnetic Separation of Reduced Iron-Rich Diasporic Bauxite with Sodium Salts

Jiang

et al. 2016

Metals

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Abstract:Recovery of iron from iron-rich diasporic bauxite ore via reductive roasting followed by magnetic separation has been explored recently. However, the efficiency of alumina extraction in the non-magnetic materials is absent. In this paper, a further study on the digestion of alumina by the Bayer process from non-magnetic material obtained after magnetic separation of reduced iron-rich diasporic bauxite with sodium salts was investigated. The results indicate that the addition of sodium salts can destroy the original occurrences of iron-, aluminum-and silicon-containing minerals of bauxite ore during reductive roasting. Meanwhile, the reactions of sodium salts with complex aluminum-and silicon-bearing phases generate diaoyudaoite and sodium aluminosilicate. The separation of iron via reductive roasting of bauxite ore with sodium salts followed by magnetic separation improves alumina digestion in the Bayer process. When the alumina-bearing material in bauxite ore is converted into non-magnetic material, the digestion temperature decreases significantly from 280 • C to 240 • C with a nearly 99% relative digestion ratio of alumina.

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“…In these industries, the bauxite must necessarily have low iron content to prevent discolourisation, and in general, hematite content should be lower than 2%. Such low iron content bauxite may be used in the production of filler, brick suitable for industrial applications, and other refractory items (3,4).…”

Section: Introductionmentioning

confidence: 99%

Bauxite Enrichment by Microwave-Magnetising Roasting Using Sawdust as Reducing Agent

Ofori-Sarpong¹

2014

AJCHE

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As high grade bauxite is getting depleted in several parts of the world, bauxite with high iron content is becoming increasingly important, and this trend has called for studies into the reduction of iron in bauxite. This study investigated the use of microwave energy in the magnetising roasting of high-iron bauxite using sawdust as reducing agent. Mineralogical studies revealed gibbsite and goethite as the main constituents of bauxite. The sawdust utilised had a fixed carbon content of 7.2% and ash, 1.7%. Microwave heating responses of bauxite and sawdust were determined as a function of mass and time, and both materials proved to be active microwave absorbers as they heated rapidly. Magnetising roasting of the bauxite sample was conducted with 20-40% sawdust at temperatures between 870 o C and 880 o C. After magnetic separation, the major phase in the magnetic fraction was magnetite, while gibbsite and boehmite were the major phases in the non-magnetic fraction. The alumina content of the non-magnetic fraction increased to 87.5% from an as-received sample grade of 53.6%. The use of sawdust in this manner satisfies a dual role of environmental clean-up and bauxite enrichment.

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The Effect of Pretreatment on Magnetic Separation of Ferruginous Minerals in Bauxite

Cited by 31 publications

References 0 publications

Red mud as secondary source for critical raw materials – extraction study

Red mud as secondary source for critical raw materials – extraction study

Digestion of Alumina from Non-Magnetic Material Obtained from Magnetic Separation of Reduced Iron-Rich Diasporic Bauxite with Sodium Salts

Bauxite Enrichment by Microwave-Magnetising Roasting Using Sawdust as Reducing Agent

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