Acid Leaching Process Chromite Ore
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Acid Leaching Process Chromite Ore

Leaching of Valuable Elements from the Waste Chromite

2020-8-11  crucial factor in the acid-leaching process of an ore or residue.33 To figure out the influence of L/S, a series of experiments with varying L/S from 4 to 10 mL/g at 60% of w/ w%H 2 SO 4, 373 K, and a leaching time of 6 h were conducted, and the

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Leaching kinetics of acid-soluble Cr(VI) from chromite ore ...

The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly ...

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Sulfuric acid leaching of South African chromite. Part 1 ...

2014-7-10  Another cleaner process beyond the proof of concept stage for processing chromite and other refractory ores (Bayca, 2013, Li et al., 2008) is the acid leaching process. It shows that chromite dissolves in concentrated sulfuric acid below 200 °C in the presence of oxidant without generating any chromium (VI)-bearing substance (Ji, 2012).

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Decomposition mechanism of chromite in sulfuric acid ...

2017-12-13  The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly understood. In this work, binary spinels of Mg–Al, Mg–Fe, and Mg–Cr in the powdered and lump states were synthesized and used as raw materials to investigate the decomposition mechanism of chromite

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Comparative study of alkali roasting and leaching of ...

2016-10-1  Various processes such as soda-ash roasting (Antony et al., 2001), acid leaching (Geveci et al., 2002, Zhao et al., 2014), alkali leaching (Xu et al., 2005, Zhang et al., 2010) and alkali fusion (Hundley et al., 1985) have been developed for the processing of chromite ores in order to produce sodium chromate (Na 2 CrO 4), which is the primary ...

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Sulfuric acid leaching of Turkish chromite concentrate ...

2002-11-1  The results of experiments are given in Table 1.As can be seen from this table, without the addition of perchloric acid, the maximum recovery obtainable was about 58%, after leaching at 175 °C, for 2 h with 70% H 2 SO 4 solution for experiment number 9. It can be said that the possible reason for this relatively low recovery was the stoppage of the reaction due to insufficient attack of ...

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Comparative study of alkali roasting and leaching of ...

2017-1-14  soda-ash roasting (Antony et al., 2001), acid leaching (Geveci et al., 2002; Zhao et al., 2014), alkali leaching (Xu et al., 2005; Zhang et al., 2010) and alkali fusion (Hundley et al., 1985) have been developed for the processing of chromite ores in order to produce sodium chromate (Na 2CrO 4), which is the primary product used for the ...

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Sulfuric acid leaching kinetics of South African chromite ...

2015-3-4  The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching conditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a ...

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Leaching of a low grade Egyptian chromite ore -

1996-11-1  The chromite was ground for 25 min under 10 bar oxygen partial pressure using sodium hydroxide concentration of 200 g/1. It was found that 90% chromium extraction is reached after 90 min leaching time at 240.

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Mineral processing: leaching process of chromium and ...

2019-5-6  The percent of reacted chromite ore can be maximized by increasing the roasting time of chromite ore with Na 2 CO 3 and also by raising the annealing temperature up to 1400 °C [ 26 ]. Antony et al. [ 26] have reported that, maximum percent formation and leaching of sodium chromate generally did not exceed 80–82%.

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Acid leaching of chromite - ScienceDirect

1994-5-1  Pressure leaching using sulphurie acid to dissolve chromite ore was investigated. The most favourable conditions 605 606 E VARDAR ~'I dl for sulphuric acid leaching of chromite to extract chromium was at 250, lbr 30 rain., using 50% H2SO4 (by weight) and chromite ore

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Leaching of Valuable Elements from the Waste Chromite

2020-8-11  crucial factor in the acid-leaching process of an ore or residue.33 To figure out the influence of L/S, a series of experiments with varying L/S from 4 to 10 mL/g at 60% of w/ w%H 2 SO 4, 373 K, and a leaching time of 6 h were conducted, and the

More

Leaching kinetics of acid-soluble Cr(VI) from chromite ore ...

The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly ...

More

Decomposition mechanism of chromite in sulfuric acid ...

2017-5-19  The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly understood. In this work, binary spinels of Mg-Al, Mg-Fe, and Mg-Cr in the powdered and lump states were synthesized and used as raw materials to investigate the decomposition mechanism of chromite in ...

More

Sulfuric Acid Leaching of South African Chromite. Part 2 ...

The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly ...

More

Comparative study of alkali roasting and leaching of ...

2016-10-1  Various processes such as soda-ash roasting (Antony et al., 2001), acid leaching (Geveci et al., 2002, Zhao et al., 2014), alkali leaching (Xu et al., 2005, Zhang et al., 2010) and alkali fusion (Hundley et al., 1985) have been developed for the processing of chromite ores in order to produce sodium chromate (Na 2 CrO 4), which is the primary ...

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A clean and efficient leaching process for chromite ore ...

During the leaching process, other accompanying elements such as aluminum and silicon were extracted out from the chromite ore as well. However, their leaching products easily formed a compound of ...

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Recovery of chromium from residue of sulfuric acid ...

2018-1-1  For the sulfuric acid leaching process of chromite, the produced Cr-rich leachate has usually pH ≈ −1.5, which needs to be adjusted pH > 2 for subsequent treatments. On the basis of this and the experimental findings from this work, the Cr-rich solution obtained from chromium recovery can be used for the pH adjustment, and the unreacted ...

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Comparative study of alkali roasting and leaching of ...

2017-1-14  soda-ash roasting (Antony et al., 2001), acid leaching (Geveci et al., 2002; Zhao et al., 2014), alkali leaching (Xu et al., 2005; Zhang et al., 2010) and alkali fusion (Hundley et al., 1985) have been developed for the processing of chromite ores in order to produce sodium chromate (Na 2CrO 4), which is the primary product used for the ...

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(PDF) (Bio)leaching Behavior of Chromite Tailings

The optimum process conditions of leaching treatment were found to be a temperature of 176 °C, a dichromic acid/chromite mass ratio of 0.12, and a sulfuric acid concentration of 81%.

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Leaching kinetics of acid-soluble Cr(VI) from chromite ore ...

2011-4-26  Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial waste water containing HF. The results show that HF can effectively destabilize the Cr(VI)-bearing minerals, resulting in the mobilization of Cr(VI) from COPR into the leachate. Particle ...

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Leaching of chromite ore in concentrated KOH by

2017-5-4  The leaching process of chromite ore is a typical LO reaction, and the oxygen mass transfer in the KOH sub-molten salt solution is a vital factor. In order to ... carboxylic acids (citric, lactic, malic and tartaric) to carbon dioxide and water in comparison with other transition metal oxide such as Fe 2 O 3, MnO 2, Co 3 O 4

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leaching process for chromite - capeatlanticdistrictumw

leaching with caustic of the chromite plant. process of extraction from chromite oreA clean and efficient leaching process for chromite oreAs shown in Fig 6 temperature was significant to the dissolution process for chromite ore The chromium extraction was relatively low after 5 h reaction at 160 °C (45%) but increased with leaching temperature and a high extraction was obtained at 220 °C ...

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Sulfuric Acid Leaching of South African Chromite. Part 2 ...

The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly ...

More

Long-Term Leaching Behavior of Chromite Ore Processing ...

Leaching characteristics of chromium ore processing residue (COPR) for the long term (simulating a 20-year leaching scenario) were investigated using laboratory flow-through column testing with synthetic rainwater and groundwater for 250 pore volumes of flow (PVFs).

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Process for Chromite - MDPI

2019-1-28  acid treatment process: (i) the chromium in the chromite is difficult to leach because of the high stability of the chromite spinel in sulfuric acid solution at room temperature and atmospheric pressure; (ii) iron, magnesium, and aluminum ions can be released into the leachate concomitantly as chromium is leached, and the removal of impurities is

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Leaching Mechanism of Cr(VI) from Chromite Ore

The leaching behavior of hexavalent chromium (Cr(VI)) and major metal elements relevant to Cr(VI) leaching from chromite ore processing residue (COPR) to HNO3 are investigated by batch leaching tests. According to the test results, aqueous Cr(VI) accounted for 70-80% of the content of total Cr. Cr(VI) concentration was controlled by the dissolution degree of Cr(VI)-bearing minerals (such as ...

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Sulfuric acid leaching kinetics of South African chromite ...

The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching conditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a ...

More

Leaching of Valuable Elements from the Waste Chromite ...

2020-8-11  The efficacious treatment and resource utilization of the chromite ore processing residue (COPR) is important for chromate salt production. In this study, the leaching of valuable elements from the waste COPR was investigated. X-ray diffraction (XRD ...

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Acid leaching industrial process Britannica

Acid leaching is commonly performed by agitating an ore-leach mixture for 4 to as long as 48 hours at ambient temperature. Except in special circumstances, sulfuric acid is the leachant used; it is supplied in amounts sufficient to obtain a final leach liquor at about.

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