Development of a Bleaching Process for a Kaolin of Industrial Interest by Oxalic, Ascorbic, and Sulfuric Acids:  Preliminary Study Using Statistical Methods of Experimental Design

Vegliò, Francesco; Passariello, B.; Toro, and L.; Marabini, A.M.

doi:10.1021/ie950427s

Cited by 39 publications

(21 citation statements)

References 15 publications

(21 reference statements)

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“…Extraction from low grade kaolin can be explained by a shrinking core model [15] in which: aA fluid + bB particle Product (2) If the reaction rate is controlled by diffusion through an inert product layer, the integrated rate equation is as follows [16]:…”

Section: Kinetic Analysismentioning

confidence: 99%

Kinetic Study of Iron Dissolution from Low Grade Kaolin Using Oxalic Acid Solutions

et al. 2012

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ABSTRACTKaolin is an important material that is used in industrial applications, including ceramics, paper, paints, fiberglass, inks, pharmaceuticals, and cement. The presence of impurities, particularly iron and titanium bearing materials, imparts color to kaolin. During weathering or hydrothermal alteration, significant levels of iron oxides can be deposited that leave a concentrated kaolinitic clay unusable for industrial application. Therefore, several chemical methods have been applied to kaolin beneficiation in order to reduce these contaminants. Ferric oxide dissolution is of particular interest for producers of industrial minerals such as kaolin. The objective of this work was to examine the kinetics of iron dissolution form low grade kaolin using oxalic acid solutions. The effects of acid concentration and reaction temperature were studied. It was determined that the iron dissolution rate increases with oxalic acid concentration, temperature. Leaching data showed that iron dissolution from low grade kaolin is due to diffusion through the product layer. The activation energy of the process was 46.32 kJ/mol.

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Section: Kinetic Analysismentioning

confidence: 99%

Kinetic Study of Iron Dissolution from Low Grade Kaolin Using Oxalic Acid Solutions

et al. 2012

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“…It forms different complexes with D2EHPA (H 2 A 2 ) such as Fe (OH)A 2 (HA) 2 and Fe(HA 2 ) 3 when it is extracted from aqueous phase having different acidities (Shuqiu and Chen, 1989).When iron is extracted from a highly acidic and loaded on the D2EHPA phase, its stripping from it is difficult even with concentrated H 2 SO 4 acid. In view of the previous difficulty, it is therefore desirable to examine the feasibility of using other reagents such as oxalic acid, which has been used on a large scale for the removal of iron stains from kaoline, quartz, and bauxite (Bonney, 1994;Ve g lio et al 1996;Ambikadevi and M. Lalithambika, 2000). The use of oxalic acid for removal of iron from alkyl pyrophosphoric acid has also been reported (Worthington and A. Magdics, 1984).…”

Section: Introductionmentioning

confidence: 99%

Removal of Iron From Synergistic Di-2-Ethylhexyl Phosphoric Acid and Tri Butyl Phosphate Organic Solvent Loaded With Uranium From Sulfate Leach

Amin¹

2018

Nuclear Sciences Scientific Journal

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Uranium leach liquor was obtained by uranium leaching of a technological sample of Gattar GV area, eastern desert, Egypt. Ore was subjected to uranium extraction using the synergistic organic solvent technique; the solvent used was mixture of di-2-ethylhexyl phosphoric acid and tributyl phosphate. The effect of sulfuric acid concentration, effect of leaching time, effect of leaching temperature, and liquid/ solid phase ratio were investigated to produce sulfate leach liquor from GV. Synergistic 0.5 M D2EHPA and 0.5 M TBP organic solvent agitated with leach liquor solution of GV (Org./Aq. 2:1) for 5 min at room temperature were the optimum conditions for uranium extraction of 96 %. Iron co-extracted into the loaded organic phase with uranium was removed by using oxalic acid (scrubbing process). In this concern, different parameters were investigated such as, effect of scrubbing time, effect of oxalic acid concentration, effect of temperature, and effect of organic to aqueous phase ratio.

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“…Consequently, several chemical methods have historically been applied to kaolin beneficiation in order to reduce these contaminants [2,[3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Statistical Treatment of Bleaching Kaolin by Iron Removal

et al. 2017

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In the present study, oxalic acid was used as a leaching reagent to remove iron from a kaolin mineral. Statistical analysis was conducted to determine the most influential factors in the dissolution of iron from the kaolin mineral. Our goal was ferric iron solubilization and its reduction to ferrous iron to improve the iron removal in the acid medium. Leaching experiments were conducted at atmospheric pressure. A two-level factorial design of the type 2<sup>4</sup> was utilized. The dependent variable was the percentage of dissolved iron, and the dependent variables in this study were acid concentration (0.35 and 0.50 M), temperature (75 °C and 100 °C), leaching time (2 and 4 h), and pH (1.5 and 2.5). An analysis of variance revealed that the effects of the factors temperature (b), pH (d), and the combined effects of temperature and time (bc) resulted in the maximum dissolution of iron of 88% at 100 °C, giving a kaolin mineral with a whiteness index 93.50%.

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Development of a Bleaching Process for a Kaolin of Industrial Interest by Oxalic, Ascorbic, and Sulfuric Acids: Preliminary Study Using Statistical Methods of Experimental Design

Cited by 39 publications

References 15 publications

Kinetic Study of Iron Dissolution from Low Grade Kaolin Using Oxalic Acid Solutions

Kinetic Study of Iron Dissolution from Low Grade Kaolin Using Oxalic Acid Solutions

Removal of Iron From Synergistic Di-2-Ethylhexyl Phosphoric Acid and Tri Butyl Phosphate Organic Solvent Loaded With Uranium From Sulfate Leach

Statistical Treatment of Bleaching Kaolin by Iron Removal

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