Arsenic stabilization of calcium arsenate waste by hydrothermal precipitation of arsenical natroalunite

Viñals, J.; Sunyer, Alba; Molera, Pere; Cruells, M.; Llorca, N.

doi:10.1016/j.hydromet.2010.06.013

Cited by 41 publications

(18 citation statements)

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“…Recent studies have shown that hydrothermal treatment can effectively achieve the stabilization of hazardous waste but also realize the dehydration of the waste and hence reduce the volume of waste [ 24 ]. Vinals et al [ 25 ] found that arsenic in calcium arsenate waste from a copper smelter can be stabilized by hydrothermal treatment, generating the precipitation as arsenical natroalunite which is effective for long-term storage. Qiu et al [ 26 ] indicated that hydrothermal treatment assisted by microwave heating is a feasible approach for the solidification of heavy metals in fly ash.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

Yao

Min

et al. 2018

IJERPH

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Arsenic sulfide residue (ASR), a by-product from the treatment of arsenic-bearing acidic wastewater, is abundantly generated but not properly disposed of in China. The utilization of such high-content arsenic waste residue is limited by the market. The traditional methods of stabilization/solidification (S/S) by lime cement or iron salt have a large mass/volume addition, high dumping cost and secondary pollution risk. In this paper, hydrothermal technology was used to treat three kinds of ASRs obtained from different smelters to minimize waste. The leaching toxicity and chemical speciation of the generated products was also evaluated by TCLP and BCR analyses. It was found that the hydrothermal treatment could greatly reduce the volume and moisture content of the ASRs. TCLP tests showed that the leachability of arsenic and heavy metals significantly decreased after the treatment. According to the BCR analysis, most of the unstable As, Cd and Cr transformed into a residual fraction. Finally, XRD, SEM, Raman and XPS techniques were carried out to reveal the mechanism. As a result, hydrothermal treatment can efficiently achieve the dehydration, volume reduction and stabilization/solidification of ASRs.

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Section: Introductionmentioning

confidence: 99%

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

Yao

Min

et al. 2018

IJERPH

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“…Other phases with low solubilities are mimetite and mimetitepyromorphite solid solutions (Flis et al, 2011), but they require the presence or addition of lead to the polluted sediments or waste form. Substitution of arsenic into common sulfates, such as jarosite (Savage et al, 2005;Johnston et al, 2012, Forray et al, 2014 or alunite/natroalunite (Vinals et al, 2010, Luo et al, 2015, Sunyer et al, 2016 has also been considered, and may be applicable in systems with low pH and high sulfate concentrations (Welham et al, 2000). Kocourková et al (2011) argued against jarosite/alunite as an arsenic-storage medium, stating that "beudantite and scorodite represent a long-term option for immobilization of arsenic, but arsenic stored in jarosite can be mobilized relatively easily".…”

Section: Document Version Final Published Versionmentioning

confidence: 99%

Thermodynamic properties of mansfieldite (AlAsO₄·2H₂O), angelellite (Fe₄(AsO₄)₂O₃) and kamarizaite (Fe₃(AsO₄)₂(OH)₃·3H₂O)

et al. 2018

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Thermodynamic data for the arsenates of various metals are necessary to calculate their solubilities and to evaluate their potential as arsenic storage media. If some of the less common arsenate minerals have been shown to be less soluble than the currently used options for arsenic disposal (especially scorodite and arsenical iron oxides), they should be further investigated as promising storage media. Furthermore, the health risk associated with arsenic minerals is a function of their solubility and bioavailability, not merely their presence. For all these purposes, solubilities of such minerals need to be known. In this work, a complete set of thermodynamic data has been determined for mansfieldite, AlAsO4·2H2O; angelellite, Fe4(AsO4)2O3; and kamarizaite, Fe3(AsO4)2(OH)3·3H2O, using a combination of high-temperature oxide-melt calorimetry, relaxation calorimetry, solubility measurements, and estimates where possible and appropriate. Several choices for the reference compounds for As for the high-temperature oxide-melt calorimetry were assessed. Scorodite was selected as the best one. The calculated Gibbs free energy of formation (all data in kJ·mol–1) is –1733.4 ± 3.5 for mansfieldite, –2319.2 ± 7.9 for angelellite and –3056.8 ± 8.5 for kamarizaite. The solubility products for the dissolution reactions are –21.4 ± 0.5 for mansfieldite, –43.4 ± 1.5 for angelellite and –50.8 ± 1.6 for kamarizaite. Available, but limited, chemical data for the natural scorodite–mansfieldite solid-solution series hint at a miscibility gap; hence the non-ideal nature of the series. However, no mixing parameters were derived because more data are needed. The solubility of mansfieldite is several orders of magnitude higher than that of scorodite. The solubility of kamarizaite, on the other hand, is comparable to that of scorodite, and kamarizaite even has a small stability field in a pH-pε diagram. It is predicted to form under mildly acidic conditions in acid drainage systems that are not subject to rapid neutralization and sudden strong supersaturation. The solubility of angelellite is high, and the mineral is obviously restricted to unusual environments, such as fumaroles. Its crystallization may be enhanced via its epitaxial relationship with the much more common hematite. The use of the scorodite–mansfieldite solid solution for arsenic disposal, whether the solid solution is ideal or not, is not practical. The difference in solubility products of the two end-members (scorodite and mansfieldite) is so large that almost any system will drive the precipitation of essentially pure scorodite, leaving the aluminium in the aqueous phase.

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“…Arsenic stabilization also involves copper smelter industry. Viñals et al (2010) investigated precipitation of arsenical natroalunite, that is suitable for long-term storage, from a calcium arsenate waste coming from a copper pyrometallurgical plant. Calcium arsenate waste was leached with H 2 SO 4 and ozonized at 25°C to convert As(III) to As(V).…”

Section: Environmental Management and Sustainable Developmentmentioning

confidence: 99%

Removal of Arsenic from Wet Scrubbing Wastewater

Ferella

Michelis

Vegliò³

2016

EMSD

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Arsenic removal is hindered by its valence state. Addition of lime into wastewater containing arsenic gives benefits through the formation of low-soluble calcium arsenate, but the mechanism involved in the reduction of arsenic dissolution is not well known yet. Hence, in the present work different Ca/As ratios from 0 to 70% w/w were tested with the aim of finding the best conditions for removal of As from water (neutral tests) or solution (acid tests) containing sulphate ions. These solutions simulated aqueous streams coming from a wet scrubber for treatment of flue gas. Moreover, 5 g L -1 of iron chloride were tested as additive in the acid tests.In the optimum operating conditions, nearly 99% precipitation yield was obtained for both As(III) and As(V) in less than 1 h; the optimum process conditions were 10 g L -1 of CaO without FeCl 3 for As(III) and 9 g L -1 of CaO and 5 g -1 FeCl 3 for As(V) in acid solutions. As regards neutral solutions, 1 g L -1 of CaO is enough to precipitate around 99% of As(III) whereas the same result for As(V) is achieved by a higher CaO concentration (40 g L -1 ). Iron chloride had a negative effect on As(III) precipitation.

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Arsenic stabilization of calcium arsenate waste by hydrothermal precipitation of arsenical natroalunite

Cited by 41 publications

References 26 publications

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

Thermodynamic properties of mansfieldite (AlAsO₄·2H₂O), angelellite (Fe₄(AsO₄)₂O₃) and kamarizaite (Fe₃(AsO₄)₂(OH)₃·3H₂O)

Removal of Arsenic from Wet Scrubbing Wastewater

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Arsenic stabilization of calcium arsenate waste by hydrothermal precipitation of arsenical natroalunite

Cited by 41 publications

References 26 publications

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

Hydrothermal Treatment of Arsenic Sulfide Residues from Arsenic-Bearing Acid Wastewater

Thermodynamic properties of mansfieldite (AlAsO4·2H2O), angelellite (Fe4(AsO4)2O3) and kamarizaite (Fe3(AsO4)2(OH)3·3H2O)

Removal of Arsenic from Wet Scrubbing Wastewater

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Thermodynamic properties of mansfieldite (AlAsO₄·2H₂O), angelellite (Fe₄(AsO₄)₂O₃) and kamarizaite (Fe₃(AsO₄)₂(OH)₃·3H₂O)