Recovery and concentration of metals from red mud by Donnan dialysis

Çengeloğlu, Yunus; Kır, Esengül; Ersöz, Mustafa; Büyükerkek, Tuĝba; Gezgin, Sait

doi:10.1016/s0927-7757(03)00198-5

Cited by 54 publications

(29 citation statements)

References 25 publications

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“…Roughly 1.0-1.5 tonnes of red mud (RM) residue are produced for each tonne of alumina and hence, millions of tonnes of caustic RM must be disposed annually worldwide [7]. Particularly, one of the main problems for all alumina industries is disposal and utilization of RM [8]. Approximately 500,000 m 3 of strong alkaline (pHE 12-13) RM-water pump is dumped annually into specially constructed dams around the Seydisehir Aluminium plant [9].…”

Section: Introductionmentioning

confidence: 99%

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Use of boron waste as a fluxing agent in production of red mud brick

Kavas

2006

Building and Environment

156

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Section: Introductionmentioning

confidence: 99%

“…The disposal of RM tailings costs the industry $3 per ton of alumina production [10]. RM is a fine-grained mixture of oxides and hydroxides, capable of removing several contaminants, as well as being widely available [7][8][9][10][11]. In addition, RM has the potential to impact the environment and groundwater seriously [10].…”

Section: Introductionmentioning

confidence: 99%

Use of boron waste as a fluxing agent in production of red mud brick

Kavas

2006

Building and Environment

156

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“…The low pH in the extractor solution may exchange with the Cr(III) ions more rapidly and stimulates diffusion of both ions due to the concentration gradient 61,62 . However, the mass transport coefficient is higher in the pH 3.0 extractor solution than in the pH 1.0 extractor solution.…”

Section: Thermogravimetric(tga)analysismentioning

confidence: 99%

“…This mixture did not improve the Cr(III) transport relative to using HNO 3 alone at pH 3.0. The high sodium ion concentration in the extractor mixture may exchange with the Cr(III) ions and stimulate ion diffusion due to the concentration gradient 61,62 , but this exchange did not occur.…”

Section: Thermogravimetric(tga)analysismentioning

confidence: 99%

Functional Ion Membranes Supported Inside Microporous Polypropylene Membranes to Transport Chromium Ions: Determination of Mass Transport Coefficient

Tapiero

Rivas

Sánchez

2014

J. Chil. Chem. Soc.

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Polypropylene (PP) membranes incorporating interpenetrating polymer networks of poly [(ar-vinylbenzyl) trimethylammonium chloride](P(ClVBTA)) and poly[sodium (styrenesulfonate)] P(SSNa) were modified via an "in-situ" radical polymerization synthesis inside the pores. The modified polypropylene membranes were characterized using SEM, ATR/FTIR, DRX, TGA, and Donnan dialysis for the transport of chromium ions. The modified membranes exhibited a percent modification between 2.5% and 4.0% in weight gain and a hydrophilic character with a water uptake capacity between 15% and 20%. The mass transport coefficient was determined using the non-linear fit of the experimental data to the exponential equation. Hexavalent chromium ions were efficiently transported by the modified membranes containing P(ClVBTA). At pH 3.0, the M4Cl.PEI (11.0×10 -6 m s -1 ), and at pH 9.0, the M3Cl (14.4×10 -6 m s -1 ) could transport hexavalent chromium ions efficiently using a 1 mol L -1 NaCl extraction agent. In the same way, the transport of trivalent chromium could be performed using membranes modified with P(SSNa). At pH 3.0 and 4.0×10 -2 mol L -1 trivalent chromium in the food chamber, the M9Na.PVA (16.3×10 -6 m s -1 ) performed efficient transport using 1×10 -3 mol L -1 HNO 3 as the extraction agent.Keywords: interpenetrating polymer network, membranes, Donnan dialysis, chromium, ion exchange, and polypropylene. INTRODUCTIONEnvironmental pollution of water, soil, and air is a serious problem when it includes oxyanions. Some oxyanion water-contaminating species employed in industry are chromate, arsenate, permanganate, hydrogen selenite, and selenate. A particular case is the derivatives of the chromium oxyanions. Chromium ions have two oxidation states in the water, for example, the trivalent chromium Cr(III) and hexavalent chromium Cr(VI).Cr(VI) produces the oxyanion (chromate) and the polyoxyanion (dichromate). These oxyanions are the more toxic ionic species and cause serious health problems such as cancer. The toxicity depends on the concentration and the exposure period 1,2 . Cr(VI) oxyanions are water-soluble across all pH ranges and accumulate well in biological systems (bioassimilable), and their speciation depends on the pH and concentration. If the pH is strongly acidic and the Cr(VI) ions are highly concentrated, the chromium ions exist as dichromate The most common methods developed to remove Cr(VI), and Cr(III) ions from polluted solutions are reduction and precipitation 9 , adsorption 10 , and ion exchange 11,12 . Membrane technologies allow for reverse osmosis, ultrafiltration, nanofiltration, dialysis, diffusion dialysis, Donnan dialysis, membrane electrolysis, and electrodialysis 4,12-14 (liquid, emulsified and supported) 13,15,16 . However, it is difficult to eliminate the oxyanions Cr(VI) and the Cr(III) ions selectively from the water. The improvement of the removal methods and the production of new functional polymer materials are very useful in the development of new technologies for removal, retention, an...

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“…It is estimated that about 90 million tonnes of RM are produced annually on the earth [2], while 10 million tonnes are expected to be produced each year in China in the near future [3], hence, the disposal and management of RM remains a challenging issue to the alumina industry. At present, RM produced from alumina plants is mostly treated by landfilling and ocean disposal [4], only a small amount was utilized for land composting [5], cement [6], building material additive [7] and metal recovery [8] in the past decades.…”

Section: Introductionmentioning

confidence: 99%