Green one-step roasting method for efficient extraction of vanadium …
Therefore, chromium, not only vanadium, has to be extracted from the vanadium-chromium slag. However, conventional roasting techniques can only extract vanadium but cannot extract chromium from the vanadium-chromium slag. It is due to that (1) Cr-spinel is more thermodynamically stable than V-spinel, vanadium is thus …
Extraction, phase transformation and kinetics of
(NH 4) 2 SO 4 roasting followed by water leaching to process nickel- chromium mixed metal oxidized (MO) ore was investigated. The optimal operating parameters were obtained after determining the influences of the molar ratio of (NH 4) 2 SO 4 to mixed oxidized ore, roasting temperature and roasting time on metal extractions. …
21.7A: Chromium Metal
Chromite ((ce{FeCr2O4})) is the most commercially useful ore, and is extensively used for extraction of chromium. Chromium is produced in two forms: Ferrochrome by the …
Chromium | SpringerLink
3.2.3 Extra-Low Carbon Ferro-Chrome. In the manufacture of extra-low carbon ferro-chrome (0.05–0.06% C), chrome ore is reduced with the silicon of ferro-silico-chrome. The reaction is exothermic, i.e. can proceed at lower temperature.At lower temperature the thick high chromium slag is made, which retards the diffusion …
Distribution and extraction of chromium from phosphate ore
To this end, the test and selection of the specific chemical reagent for efficient chromium extraction from phosphate ore were studied. The effects of some parameters were taken into consideration and optimized. The results show that the chromium content was reduced to approximately 30% in natural phosphate using citric …
Chromium (VI) Retrieval from Chromium Ore Processing
The EK experiment reached an extraction of 72% of the total leachable Cr (VI) after only 10 days of treatment and 84% after 20 days. Material texture, …
Distribution and extraction of chromium from phosphate ore
The objective of this work was to select a chemical reagent capable of efficiently extracting chromium from phosphate ore in order to reduce its content. The study of chromium speciation in phosphate ore allows us to evaluate its mobility and therefore its potential toxicity. To this end, the test and selection of the specific chemical reagent ...
Chromium processing | Extraction, Uses & Applications
Chromite deposits are mined by both underground and surface techniques. Much of the ore is rich enough to be used directly: for production of ferrochromium, a rich, lumpy ore …
Chromium Ore
Chromium is extracted from its ores by two processes. In the alkaline process, the finely ground ore is roasted with Na 2 CO 3 under oxidizing conditions at 1100 °C. The sodium …
An efficient method of chromium extraction from chromium …
DOI: 10.1016/J.HYDROMET.2016.02.020 Corpus ID: 101496228; An efficient method of chromium extraction from chromium-containing slag with a high silicon content @article{Kaiping2016AnEM, title={An efficient method of chromium extraction from chromium-containing slag with a high silicon content}, author={Yu Kaiping and Bo Chen …
Chromium
Chromium. Chromium (Cr) is a hard, bluish metallic element. The only ore of chromium is the mineral chromite and 99 percent of the world's chromite is found in southern Africa and Zimbabwe. Geologists estimate that there are about 11 billion tons of mineable chromite ore in the world, enough to supply the current demand for hundreds of years.
Chromium (Cr)
Chromium production begins with the mining of chromite ore (FeCr2O4), which is the main source of chromium. This process involves extracting chromite from open pit or underground mines. After mining, the chromite ore is initially concentrated through various processes including crushing, grinding, and gravity separation to …
Modifications to EPA Method 3060A to Improve Extraction …
It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from chromium ore processing residue (COPR). We modified various parameters of EPA 3060A toward understanding the transformation of COPR minerals in the alkaline extraction and improving extraction of Cr(VI) from NIST SRM 2701, a standard COPR …
Distribution and extraction of chromium from phosphate ore
The objective of this work was to select a chemical reagent capable of efficiently extracting chromium from phosphate ore in order to reduce its content. The study of chromium speciation in ...
Green one-step roasting method for efficient extraction of …
However, China is a country with a serious shortage of chromite resources and has relied on imports for long [12]. Therefore, chromium, not only vanadium, has to be extracted from the vanadium-chromium slag. However, conventional roasting techniques can only extract vanadium but cannot extract chromium from the vanadium …
Chromium Ore
Chromium is extracted from its ores by two processes. In the alkaline process, the finely ground ore is roasted with Na 2 CO 3 under oxidizing conditions at 1100 °C. The sodium chromate is leached from the calcine. ... The gangue present in a chromium ore has a significant effect on the temperature of the smelting zone, thereby influencing the ...
Ecofriendly Selective Extraction of Vanadium from …
Conventional vanadium (V) extraction methods for vanadium-bearing slags create high chromium content discharge Cr(VI)-containing hazardous wastes. In this article, an ecofriendly magnesiation roasting-acid leaching method is proposed to selectively extract V from the slag. In the near-zero discharge process the generation of Cr(VI) is …
Simultaneous oxidation of Cr(III) and extraction of Cr(VI) …
1. Introduction. Chromite ore processing residue (COPR) is commonly produced as the byproduct in the manufacture of chromates and dichromates by chromite-ore high-lime roasting technique [1].The residue that still contains a significant amount of chromium (Cr(VI)) is of severe environmental threat when discharged into the …
Sufficient extraction of Cr from chromium ore processing …
Chromium ore processing residue (COPR) is a hazardous waste generated during the production of chromate. Currently, approximately 10% of Cr 2 O 3 cannot be extracted after chromite sodium roasting and remains in COPR, wasting valuable Cr resources. In this study, Mg was selectively removed by using (NH 4) 2 SO 4 roasting in combination with …
Selective removal of chromium from laterite residue with …
The extracted chromium was captured by adding calcium hydroxide at pH ∼ 3.0 in the form of phosphate. Introduction. Recently, due to the increasing demand for nickel and the depletion of nickel sulfide ore, laterite nickel ore has progressively emerged as the primary raw material for nickel production [1], [2], [3]. Within nickel consumption ...
A clean and efficient leaching process for chromite ore
In order to improve the chromate salts cleaner production technology, a pressure leaching process for chromite ore in 50 wt% KOH solution was studied for the first time and the results were presented in this manuscript.It was found out that the chromium extraction rate increased significantly with the increase of temperature and oxygen …
Extraction, phase transformation and kinetics of valuable …
DOI: 10.1016/j.mineng.2020.106737 Corpus ID: 230586985; Extraction, phase transformation and kinetics of valuable metals from nickel-chromium mixed metal oxidized ore @article{Shen2020ExtractionPT, title={Extraction, phase transformation and kinetics of valuable metals from nickel-chromium mixed metal oxidized ore}, author={Xiao-yi Shen …
Efficient extraction and separation of vanadium and chromium …
Vanadium precipitation conditions and chromium reduction conditions were optimized further. 94.6% vanadium and 96.5% chromium were extracted when HCVS and Na2CO3 were mixed in the molar ratio of n ...
Sufficient extraction of Cr from chromium ore processing …
Chromium ore processing residue (COPR) is a hazardous waste generated during the production of chromate. Currently, approximately 10% of Cr2O3 cannot be extracted after chromite sodium roasting ...
Exploring Chromium Ore Consumption: New …
tion of chromium ore and the problems of resource recovery, environmental pollution, and CO 2 emis-sions. METHODS Definitions and Boundaries In this study, the system boundary is defined as a country, and the object of the analysis is chromium ore (Fig. 4). The chromium cycle can be divided into the four stages, namely production stage ...
Chromium Mining and Extraction | Chromium Mining …
The extraction of chromium predominantly occurs from chromite ore, which is commonly found in sand-like particles. Traditional surface and underground mining techniques are employed for chromite ore extraction, with open-pit mining being the prevalent method, involving the excavation of large pits to retrieve the ore.
Co-extraction of vanadium and chromium from high chromium containing
Most recently, Chen has investigated the extraction of chromium from chromite ore in 50 wt% KOH solution, and reported that under the condition of oxygen pressure 1.0 MPa and leaching temperature 220 °C, chromium extraction rate reached up to 98.0% (Chen et al., 2013). These outcomes achieved by oxidative leaching suggest …
Chromium (VI) Retrieval from Chromium Ore Processing …
Abstract. Electrokinetics (EK) was investigated as a possible technique for in-situ treatment of leachable chromium at a built site contaminated with chromium ore …
A cleaner method for preparation of chromium oxide from chromite
A new leaching process for preparing chromium oxide from chromite was studied in this paper, using Cr(VI) extracted from the remediation treatment of chromite ore processing residue (COPR) as an oxidant. Thus, the "detoxification" of deposited COPR could be achieved and no new Cr(VI)-bearing substances would be generated in …
A cleaner method for preparation of chromium oxide from chromite ore
To establish a cleaner production technology of chromium salt, the pressurized leaching process of chromite ore in 60 wt% NaOH solution, subsequent separation of a chromium salt from the leached solution and Cr 2 O 3 preparation from the intermediate product BaCrO 4 were systematically investigated, and a new highly …