Reduction of roast Movat chromite ore with carbon
Abstract. Solid-state reduction of roast Movat chromite ore with carbon was carried out as a function of the CIF eO ratio at temperatures ranging from 800°C to 900°C. The …Web
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Mineral processing: leaching process of chromium and
The current strategy reports the recovery of precious group metals (PGMs) from Na2CO3 roast of Saudi Arabian ophiolitic chromite ore at 1160 °C under …Web
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The soda-ash roasting of chromite minerals: Kinetics …
Soda-ash roasting of the chromite mineral is commonly used worldwide for the production of watersoluble sodium chromate. The formation of sodium chromate during the soda-ash roasting reaction depends on the oxygen partial pressure and availability of oxygen at the reaction front. The effects of temperature, oxygen partial pressure, charge …Web
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The soda-ash roasting of chromite ore processing residue for the
Sodium chromate is produced via the soda-ash roasting of chromite ore with sodium carbonate. After the reaction, nearly 15 pct of the chromium oxide remains …Web
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Efficient immobilization and utilization of chromite ore processing
Chromite ore processing residue (COPR) has been a severe environmental contaminant which is worthy of attention. In this study, we developed an eco-friendly and practical technology for effectively stabilizing and recovering Cr(VI) in COPR via combining FeSO 4 reducing agent and the hydrothermal treatment. A stable spinel phase product …Web
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Chromite Ore
Chromium metal is obtained commercially by heating chromite ore in the presence of carbon, aluminum, or silicon, and subsequent purification (ATSDR, 2000). Sodium chromate and dichromate are produced by roasting chromite ore with soda ash and are the primary chromium salts from which most other chromium compounds are derived (ATSDR, 2000).Web
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The soda-ash roasting of chromite ore processing residue for the
The traditional recovery of Cr from chromite ore dominantly involves roasting with Na 2 CO 3 above 1100°C (Ladd and Vanderpool, 1987;Habashi, 1997; Antony et al., 2001; Dhal et al., 2013;Li et al ...Web
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Processing of Chromite Overburden by Soda Roasting to
Several researchers have used sodium carbonate with chromite ore in the soda-ash roasting reaction. Temperatures used are above 1073 K in air. The decomposition of sodium carbonate has resulted sodium oxide to react with chromium ion (Cr 3+) under an oxidizing atmosphere. This results into the sodium chromate formation [8, 10, 11]. The ...Web
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Original Research PaperCarbothermic reduction roasting for …
Carbothermic reduction roasting for processing of ferruginous chromite ore using conventional and microwave heating 1. Introduction. The chromite ore occurs as a …Web
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(PDF) Processing of Chromite Overburden by Soda Roasting to …
Sodium chromate is produced via the soda-ash roasting of chromite ore with sodium carbonate. After the reaction, nearly 15 pct of the chromium oxide remains unreacted and ends up in the waste ...Web
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(PDF) A Review of Chromite Ore Processing Residue (COPR): …
Chromite ore processing residue (COPR) is a waste byproduct of chromate production that contains high levels of hexavalent chromium (Cr[VI]). ... with lime preventing dissolutio n when the roast ...Web
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Process flow chart for the production of a chromium salt from chromite ore.
Antony et al. [26] and Zhang et al. [27] have been processed chromite ore by roasting with sodium carbonate, limestone and dolomite at 1000-1200 °C [27]. In the current study, the traditional ...Web
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Decomposition of chromite ore by oxygen in molten NaOH–NaNO3
Introduction. Chromite ore is the most important mineral for chromate production (Ding and Ji, 2003). Traditionally, chromite ore is processed by roasting with sodium carbonate at 1200. °C in a rotary kiln with the addition of limestone and dolomite, yielding only 75% of Cr in the ore.. Furthermore, the residue discharged (2.5–3.0 ton per …Web
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Kinetics of chromite ore in oxidation roasting process
The results show that there are two stages for the oxidation roasting process of chromite ore. The oxidation reaction is very rapid in the initial stage but quite slow in …Web
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Chromite
Chromite ore is mined in over 20 countries, but about 80% of production originates from four countries; ... Calcining, roasting, smelting, and refining are pyrometallurgical processes used to recover metal. Hydrometallurgical recovery mainly employs the leaching process. It involves the use of aqueous solutions containing a …Web
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Sufficient extraction of Cr from chromium ore
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 …Web
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Chromite Ore Processing Residue in Hudson County, New …
Chromite ore processing residue occurs at over 130 sites in Hudson County, New Jersey. Many ... from dissolving when the roast is leached. A counter-current leach process is employed. The liquor released from the leach process is a deep yellow solution, satu-rated with sodium chromate. The sodium chromate isWeb
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A detoxification and value-added process for chromium ore …
Introduction. Chromite ore processing residue (COPR) is a byproduct produced in chromite processing at high temperature (1000–1200 °C). 2.5–3 tons of lime-based COPR were generated per ton of chromium salt (calculated by Na 2 CrO 4) (Fu et al., 2021).Although soda roasting (less than 0.8 tons of COPR per ton of sodium …Web
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Chromite
Chromite ore can be separated in a high-strength field, despite the presence of iron impurities. The choice of method depends on several factors, primarily the type of the gangue. ... During roasting, sulfur is removed from the pellets by 70% to 80% (due to oxidation of sulfides like pyrite). The remaining sulfur is of the sulfate type ...Web
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Preparation of Potassium Dichromate Crystals from the Chromite
In the present investigation, the oxidizing roasting process of chromite with sodium carbonate to prepare potassium dichromate crystals was studied in the microwave field with air, by heating the ...Web
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A Cr6+-Free Extraction of Chromium Oxide from Chromite Ores …
Oxidative alkali roasting of chromite is the state-of-the-art process for manufacturing chromium-containing chemicals, which involves dealing with serious environmental problems arising from handling Cr 6+-containing wastes generated in this process.In this article a new method for the extraction of Cr 2 O 3 from chromite ores is …Web
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Identification of the significant factors determining extractability of
The first and most important conclusion that can be made is that nickel and copper can effectively be leached from a complex, chromite-rich Cu-Ni-PGM ore using a sulfation roast-leach method. The results demonstrated that within the parameters of the experiments, the amount of H 2 SO 4 addition was the most influential factor to control ...Web
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Comparative study of alkali roasting and leaching of chromite …
Chromite ore and sodium carbonate are roasted at temperatures ranging between 900 °C and 1200 °C in oxidative atmosphere (Antony et al., 2001). Under these …Web
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Alkali roasting of Indian chromite ores: Thermodynamic and …
Chromium chemicals are produced through alkaline roasting of chromite ore with alkali salts (such as NaOH, Na 2 CO 3, NaNO 3 or NaFeO 2 ) with or without lime addition at temperatures of 650-1200 ...Web
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Kinetics of chromite ore in oxidation roasting process
Chromium chemicals are produced through alkaline roasting of chromite ore with alkali salts (such as NaOH, Na 2 CO 3, NaNO 3 or NaFeO 2 ) with or without lime addition at temperatures of 650-1200 ...Web
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Reduction of roast Movat chromite ore with carbon
Solid-state reduction of roast Movat chromite ore with carbon was carried out as a function of the C/FeO ratio at temperatures ranging from 800 °C to 900°C. The …Web
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A new metallurgical process for the clean utilization of chromite ore
The development of alkali roasting process has undergone three steps: the high lime roasting, the low lime roasting and the lime-free roasting. Thereinto, lime-free technology, which can prevent CaCrO 4 generation and remarkably reduce the discharged residue yield, is the most advanced chromite ore roasting technology (Weber et al., …Web
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Microstructural analyses of Cr(VI) speciation in chromite ore
Chromite Ore Processing Residue (COPR) is a solid waste generated during the high temperature (∼1200 °C) roasting process that is used to extract chromium from chromite ore (Antony et al., 2006). Lime-based roasting has been the prevalent method to complex other metals in ore (Fe, Mg, Al) and isolate Cr.Web
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(PDF) Preparation of Industrial Sodium Chromate Compound …
This study, focused on the beneficiation of a Nigerian complex chromite ore sourced from Tunga-Kaduka, Anka Local Government of Zamfara State, Nigeria, assaying 45.85% Cr 2 O 4 and 54.15% mineral ...Web
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Preparation of Oxidized Pellets with Chrome Ore | SpringerLink
The microstructure and mechanical strength variations of chromite pellets preheated and roasted in air were studied systematically. The results show that the chromite (Fe,Mg)(Cr,Fe,Al) 2 O 4 is oxidized to magnesium-rich (Mg,Fe)(Cr,Fe,Al) 2 O 4 and ferrochromium complex oxide (Cr,Fe,Al) 2 O 3 in the preheating process over 500 …Web
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