>Home>Products>Roasting And Leaching Process For Chromium

Roasting And Leaching Process For Chromium:

Physical Chemistry of Roasting and Leaching Reactions for ...

高达12%返现 · Traditionally chromium chemical extraction has been carried out with alkali and CaO roasting, which led to major environmental issues due to CaCrO 4 /Na 2 CrO 4 release. In this review we examine the physical chemistry of both the low- and high-temperature roasting processes, which oxidizes the Cr 3+ to Cr 6+ state.

Read More
Roasting and leaching behaviors of vanadium and chromium ...

高达12%返现 · May 10, 2018 · Calcification roasting–acid leaching of high-chromium vanadium slag (HCVS) was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium. The effects of the purity of CaO, molar ratio between CaO and V2O5 (n(CaO)/n(V2O5)), roasting temperature, holding time, and the heating rate used in the oxidation–calcification processes were

Read More
Roasting and leaching behaviors of vanadium and chromium ...

The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses

Read More
Mineral processing: leaching process of chromium and ...

高达12%返现 · May 06, 2019 · The current strategy reports the recovery of precious group metals (PGMs) from Na 2 CO 3 roast of Saudi Arabian ophiolitic chromite ore at 1160 °C under atmospheric O 2.The influence of roasting temperature (960–1200 °C) and leaching agents (H 2 O, HCl, H 2 SO 4) and their concentrations on the recovery of PGMs was studied.Chromite roast concentrates a reasonable

Read More
Recovery of chromium by calcium-roasting, sodium-roasting ...

高达12%返现 · Oct 20, 2020 · Soda roasting–water leaching process was investigated to leach out chromium from these leaching residues (Wen et al. 2019a). During the roasting process, the chromium-containing phase ((Fe 0.6 Cr 0.4 ) 2 O 3 ) reacted with Na 2 CO 3 and formed Na 2 CrO 4 , and then leached out in the water leaching process, at last, a purity of 87.4% Cr 2 O 3 ...

Read More
Comparative study of alkali roasting and leaching of ...

Oct 01, 2016 · The thermodynamic analysis of the roasting process is discussed in terms of designing the process. ... Physical chemistry of roasting and leaching reactions for chromium chemical manufacturing and its impact on environment — a review. Materials Processing Fundamentals, John Wiley & Sons, Inc. (2013), pp. 225-236.

Read More
An efficient method of chromium extraction from chromium ...

Jun 01, 2016 · In contrast, 98.41% of the chromium was obtained from the slag after desilication under the same roasting conditions. The combined process of desilication, lime-free roasting and water leaching provides a suitable method for treating chromium-containing slag with high silicon content.

Read More
The Effect of Chromium on the Roasting Process of Vanadium ...

However, there are only a few studies of elements’ effects on the salt roast vanadium process with the addition of calcium (every 1% increase of CaO in slag would cause a 4.7%–9.0% V2O5 loss [18]). This study will investigate the effect of chromium on salt roasting to provide a theoretical basis for the

Read More
An efficient utilization of chromium–containing vanadium ...

Aug 15, 2019 · An efficient process to utilize the industrial waste, chromium–containing vanadium tailings was proposed. • 91.51% chromium was extracted after soda roasting–water leaching, and 87.40% chromium oxide was prepared further.

Read More
Recovery of vanadium and chromium from leaching solution ...

Aug 15, 2021 · The process flow chart of the separation and recovery of vanadium and chromium from leaching solution of sodium roasting vanadium slag was shown in Fig. 14. Download : Download high-res image (109KB) Download : Download full-size image; Fig. 13. XRD pattern of the V 2 O 5 product.

Read More
Effective Chromium Extraction from Chromium-containing ...

produce sodium chromate in sodium roasting process.8,9) During the chromium extraction process, the recovery rate is controlled by the salt roasting step in which chromium species in high valence states, such as sodium chromate, are produced. These compounds are readily soluble in the sub-sequent leaching step. Therefore, oxidation of chromite ores

Read More
Selective Recovery of Chromium From Ferronickel Slag via ...

Chromium was selectively recovered from ferronickel slag by roasting the slag with addition of Na 2 O 2, followed by water leaching.The thermodynamic analysis revealed that in the presence of Na 2 O 2 at appropriate temperatures, the Cr 2 O 3 in the ferronickel slag can be converted to NaCrO 2, instead of Na 2 CrO 4, which prevents the formation of highly toxic Cr (VI).

Read More
The Effect of Chromium on the Roasting Process of

However, there are only a few studies of elements’ effects on the salt roast vanadium process with the addition of calcium (every 1% increase of CaO in slag would cause a 4.7%–9.0% V2O5 loss [18]). This study will investigate the effect of chromium on salt roasting to provide a theoretical basis for the

Read More
(PDF) Comparative study of alkali roasting and leaching of ...

The highest TiO2 purity obtained after roasting at 1000 °C for 2 h and double leaching with water and organic acids was 84 wt.%. At low temperature (400 °C) the recovery of chromium was higher ...

Read More
Extraction Behavior of Vanadium and Chromium by ...

The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses

Read More
An efficient utilization of chromium–containing vanadium ...

Aug 15, 2019 · An efficient process to utilize the industrial waste, chromium–containing vanadium tailings was proposed. • 91.51% chromium was extracted after soda roasting–water leaching, and 87.40% chromium oxide was prepared further.

Read More
Step-Adsorption of Vanadium (V) and Chromium (VI) in the ...

Apr 14, 2020 · The common methods for leaching out vanadium and chromium were hydrometallurgical technologies, like sodium salt roasting-water leaching 16,

Read More
Processes | Free Full-Text | Optimization of Roasting ...

Oct 03, 2021 · The process of sodium roasting and water leaching is able to effectively extract vanadium (V) and tungsten (W) from spent SCR catalysts. To improve the efficiencies of V and W, different sodium additives were first investigated in the roasting process. The results revealed that the process of NaCl-NaOH composite roasting and water leaching ...

Read More
CN106629846A - Method for preparing ammonium polyvanadate ...

The invention discloses a method for preparing ammonium polyvanadate from a sodiumizing, roasting and leaching solution. The method comprises the following steps: adding an alkaline substance into the sodiumizing, roasting and leaching solution, stirring and filtering to obtain a sodium vanadate solution; adjusting the pH, then adding an impurity removing agent, stirring and filtering to ...

Read More
Sulfation–Roasting–Leaching–Precipitation Processes for ...

Bottom ash (BA) is mainly composed of compounds of Al, Fe, Ca, and traces of rare earth elements (REEs). In this study, the selective recovery of erbium (Er) as REEs by means of sulfation–roasting–leaching–precipitation (SRLP) using BA was investigated. A pre-treatment process of sulfation and roasting of BA was developed to selectively recover REEs using ammonium oxalate

Read More
Extraction Behavior of Vanadium and Chromium by ...

ABSTRACT Calcification roasting-acid leaching were conducted to investigate the extraction behavior of vanadium and chromium from high-chromium vanadium slag (HCVS). The conditions were optimized by response surface methodology (RSM). Results showed that when HCVS and CaO were mixed in m(CaO)/m(V2O5) of 0.62, then roasted from room temperature to 840 °C and maintained for 170 min,

Read More
Caustic Roasting and Leaching of Electric Arc Furnace Dust ...

Jul 18, 2013 · After roasting and leaching, the zinc recovery was found to be about 95%, while the majority of the iron oxide remained in the leach residue. The lead, cadmium and chromium recoveries were approximately 85, 89 and 37%, respectively, for roasting tests in which moisture was added. Without a moisture addition in roasting, the lead recovery ...

Read More
Manufacture of chromates - LITTLE INC A

Process of making sodium chromate from chrome ore which comprises: First, removing the less refractory chromium compounds from the '~ ore by roasting a briquetted mixture containing at least 30% voids and consisting of an alkaline compound of sodium and chromite ore in an amount approximately 100% in excess of the theoretical equivalent of ...

Read More
Value-added strategies for the sustainable handling ...

Feb 05, 2021 · The key task of process design is also to indicate the direction of waste management, in the form of slag after leaching or roasting. A highly efficient method of recovery of copper, zinc and cobalt (recovery at the level of 95%, 90%, 90% respectively) by means of sulphuric acid leaching, roasting and water leaching was proposed.

Read More
Roasting and leaching behaviors of vanadium and chromium ...

Sep 13, 2017 · Calcification roasting–acid leaching of high-chromium vanadium slag (HCVS) was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium. The effects of the purity of CaO, molar ratio between CaO and V 2 O 5 ( n (CaO)/ n (V 2 O 5 )), roasting temperature, holding time, and the heating rate used in the oxidation–calcification processes were investigated.

Read More
A novel roasting process to extract vanadium and chromium ...

Under the optimum microwave roasting conditions (1 NaOH/NaNO 3 mass ratio, 450 ℃ roasting temperature, and 10 min roasting time), the leaching rates of vanadium and chromium were 94.11% and 90.81%, respectively. In the leaching process, the reaction mechanism for the water leaching process was proposed. The process showed that leaching time ...

Read More
Roasting and leaching behaviors of vanadium and chromium ...

Calcification roasting-acid leaching of high-chromium vanadium slag (HCVS) was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium. The effects of the purity of CaO, molar ratio between CaO and V2O5 ( n(CaO)/ n(V 2 O 5 )), roasting temperature, holding time, and the heating rate used in the oxidation-calcification processes were investigated.

Read More
The Effect of Chromium on the Roasting Process of Vanadium ...

We simulated the roasting process of chromium by mixing Cr2O3 and Na2CO3 to analyze the influence of chromium on roasting vanadium slag. Samples were characterized by XRD, thermal analysis and SEM at different temperatures: Cr2O3 and Na2CO3 began to react at 500 °C. When the chromium oxide content was about 3.2%, the conversion rate of V reached the maximum value of 95%.

Read More
Microwave Roasting and Acid Leaching of Vanadium and ...

While the leaching ratio of chromium is 3.98%. During roasting process, vanadium is oxidized to acid-soluble CaV2O5, Ca2V2O7, and CaMgV2O7. After leaching, chromium mainly exists in form of chromohercynite (FeCr2O4) and chrome-manganese spinel (Mn1.5Cr1.5O4) in leaching residues.

Read More
Caustic Roasting and Leaching of Electric Arc Furnace Dust ...

Jul 18, 2013 · After roasting and leaching, the zinc recovery was found to be about 95%, while the majority of the iron oxide remained in the leach residue. The lead, cadmium and chromium recoveries were approximately 85, 89 and 37%, respectively, for roasting tests in which moisture was added. Without a moisture addition in roasting, the lead recovery ...

Read More
Effective Chromium Extraction from Chromium-containing ...

Chromium slags without vanadium were synthesized in the laboratory to mimick mineralogical characteristics of Pan-steel vanadium slag and characterized by XRD, SEM/EDS and TG-DSC techniques. Conditions for Cr extraction from the chromium slag after sodium roasting by leaching with water were studied and optimized.

Read More
Chromium is one of the most abundant elements in | Chegg

Chromium is one of the most abundant elements in Earth's Crust and it is mined as the mineral, FeCr204. South Africa, Kazakhstan, India, Russia, and Turkey are substantial producers. For the production of pure chromium, the iron has to be separated from the mineral in a two step roasting and leaching process.

Read More
Reclamation of reactive metal oxides from complex minerals ...

Nov 30, 2014 · In this context, alkali roasting and leaching as a novel approach for alumina, chromium oxide, titanium dioxide, rare-earth and vanadium pentoxide recovery is presented and discussed with examples for the separation of metal values.

Read More
CN103614566A - Method for extracting vanadium and chromium

The invention discloses a method for extracting vanadium and chromium from converter vanadium chromium slag. The method comprises the following steps: 1) adding Na2CO3 into the vanadium chromium slag, mixing uniformly and carrying out oxidizing roast on the mixture, wherein the addition of Na2CO3 is controlled according to a molar ratio of V2O3/Na2CO3 in the vanadium chromium slag

Read More
Multistage utilization process for the gradient-recovery ...

A multistage utilization process was developed to fully recover valuable metals from vanadium-bearing converter slag and reduce the content of hazardous elements, such as vanadium and chromium, in the tailings. A mechanical activation-calcification roasting-acid leaching process was firstly employed

Read More
EP2450312A1 - Recovery of tungsten from waste material by ...

A method of recycling tungsten within a waste material comprises roasting the waste material in an oxidizing atmosphere for converting the tungsten and/or tungsten carbide into tungsten oxide, directly after the roasting, leaching the roasted waste material for separating tungsten components from remaining components, wherein the tungsten components are leached in an alcaline ammonia

Read More
CN101817561B - Method for pollution-free production of ...

The invention belongs to the field of chromite hydrometallurgy and chromium chemical industry, and in particular relates to a method for the pollution-free production of sodium chromate by pressure leaching of chromite. The method comprises the following steps of: 1) reacting the chromite with oxidizing gas in solution of NaOH; 2) diluting the product obtained by the step 1) and making ...

Read More
Metals | Free Full-Text | Effective Extraction of Vanadium ...

Shi studied the process of extracting vanadium from shale by sulfuric acid roasting and leaching, and found that the leaching efficiency of vanadium approached 90.1% under the optimal roasting conditions of H 2 SO 4 dosage of 52.5 wt.%, roasting temperature of 453–473 K and roasting time of 90 min. Although the sulfating roasting–water ...

Read More