Nigeria is rich is solid mineral resources, such as: Kaolin, gypsum, mica, clay, tantalite, iron ore, gemstone, silica sand.
Read More
Recycling concrete &building rubble is not only able to bring profit to investors, but also good for environment protection.
Read More
By absorbing the advanced technology from the world, we researched and designed PF series impact crusher.…
Read More
Base on the plentiful experience of producing and marketing of impact crusher, Sofol R&D institution…
Read More
Adopting technology from the world, PY Series spring cone crusher has an excellent performance in secondary…
Read More
The vibrating screen is a kind of sieving equipment of international advanced level, developed by our…
Read More
Sofol VSI Series vertical shaft impact crusher is designed by reputed German expert of Sofol and every…
Read More
1. Introduction. Chromite ore processing residue (COPR) is a solid waste generated during the production of hexavalent chromium (Cr(VI)) by alkaline high-temperature roasting and leaching [1].Millions of tons of COPR have been deposited in urban areas around the world including UK, USA, India, Pakistan and China [2], [3], …
Details
The chromium (Cr) leaching efficiency reaches 99% with ore particle size of 40 to 50 μm, NaOH-to-ore mass ratio of 4:1, NaOH concentration of 60 wt%, O2 partial pressure of 3.2 MPa, and reaction ...
Details
Chromite ore processing residue (COPR) is a typical hazardous waste, which contains Cr ... Additionally, solidification effect of AACM was determined according to the compressive strength and the leaching concentration of chromium (Cr(vi) and total Cr). According to the optimal conditions of the single-factor experiment, the highest compressive ...
Details
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 ...
Details
1. Introduction. Chromite ore processing residues (COPR) are hazardous industrial wastes which have been disposed in surface soils at many commercial and industrial sites in the USA, UK, China, Japan, India and in many other countries (Dhal et al., 2013).One of the biggest threats of COPR to the environment is the release of …
Details
Chromium is extracted from chromite ore. Chromite is an oxide mineral composed of chromium, iron, and oxygen (FeCr 2 O 4).. Companies in South Africa supply chrome ore from the lower and middle group …
Details
Abstract In this study, modeling and optimization tests were conducted on enrichment of chromite ore by Knelson concentrator. For this purpose, the three-level Box–Behnken experimental design method was applied. The analysis of variance (ANOVA) was used at 95% confidence interval to test the significance of independent variables …
DetailsThere are two types of physical process by which chromium are carried in the fluids, bulk fluid movement from one site to another (advection), and random mixing within the fluids (diffusion and dispersion) (Zhang et al. 2016). 3.1 Advection. Advection refers to the transport of matter by the motion of a fluid (Fig. 12.1).The water will flow …
Details
potential of chromite deposits depends mainly on the thickness, continuity, and grade of ore. The most important uses of chromium are in stainless steels, nonferrous alloys, and chromium plating. Chemical-grade chromium is widely used in chemicals and pigments. Chromium also is an important component in refractories.
Details
The current strategy reports the recovery of precious group metals (PGMs) from Na2CO3 roast of Saudi Arabian ophiolitic chromite ore at 1160 °C under atmospheric O2. The influence of roasting temperature (960–1200 °C) and leaching agents (H2O, HCl, H2SO4) and their concentrations on the recovery of PGMs was studied. Chromite roast …
Details
Supply of world chromite (chrome ore) has come under severe pressure over the last few years driven by strong demand for ferrochrome used in ferroalloy production for making stainless steel. ... As far as ground water is concerned hexavalent chromium concentration has been found to be nil in deep hand pumps in the postmonsoon period, …
Details
Request PDF | On Oct 1, 2023, E.L.J. Kleynhans and others published Chemical beneficiation of chromite ore to improve the chromium-to-iron ratio for ferrochrome production | Find, read and cite ...
Details
The pH of the leaching solutions was adjusted to cover a wide range between 1 and 12.5. The concentration levels for total chromium (Cr) and Cr(VI) in the leaching solutions were virtually identical for pH values >5. For pH values <5, the concentration of total Cr exceeded that of Cr(VI) with the difference between the two attributed to Cr(III).
Details
Concentration of Ore. Question. In chromite ore, the oxidation number of iron and chromium reapectively, are: + 3, + 2 + 3, + 6 + 2, + 6; ... In chromite ore, the oxidation number of iron, and chromium are respectively. View Solution. Q4.
Details
Chromium steel from chromite ore processing residue — A valuable construction material from a waste. June 2011; ... one with high concentration of iron oxide (20-33%) in a form of spinel having ...
Details
with Fe, Si, Mg, and Al elements. Most dominant phases are that of chromite and magnetite in all the samples. The amount of chromium element by % weight in all seams ranged between 20% to 28 % as obtained from the EDS. The particle size of the grains in the ore ranged between 20 to 420µm, with majority being between 150 and 200µm.
Details
A new metallurgical process for extracting chromium from chromite ore is proposed to overcome the severe chromium (VI) pollution in chromate production industry. When the 60 wt.% KOH solution was used to decompose chromite ore, the chromium and iron ions in chromite ore were oxidized into soluble K 2 CrO 4 crystal and insoluble KFe …
Details
The composition and mineralogical characteristics of the lyzed to determine the percentage extraction of chromium chromite ore influence the kinetics of the roasting process. as sodium chromate. One gram of roasted sample was The properties of chromite ores vary significantly between leached in the boiling water for 15 minutes and filtered. The
Details
The COPR samples from nine sites can be divided into two groups, one with high concentration of iron oxide (20-33%) in a form of spinel having magnetic property, and another with low concentration ...
Details
Chromite ores contain a variety of gangue. minerals such as serpentines and olivine. Therefore, concentration of chromite is. required. The most commonly used. beneficiation methods for chromite ...
Details
Chromite ore scenario – India. India ranks third in the world in chromite production, and fifth in terms of ore reserves. The majority (98.6%) of the chromite resources in the country are hosted ...
Details
Much of that chromium is unreacted insoluble chromite ore (i.e. Cr(III)) but, as a result of oxidation during ore processing, up to 30% can be chromate (Cr(VI)) (Geelhoed et al., 2003). As a ...
Details
Chromite (Fe,Mg)(Cr,Al) 2 O 4 containing up to ~55 wt% Cr 2 O 3 is the major ore mineral of chromium and is an accessory mineral in many ultramafic rocks. Chromitite forms Cr-rich ore bodies, in which the content of chromite exceeds 30 vol.%; this results in local increase in the chromium concentration in the Earth's mantle.
Details
1. Introduction. Chromite ore processing residue (COPR) is classified as hazardous waste due to its high concentration of chromium (Cr), and Cr leachate from COPR, especially Cr(Ⅵ), is toxic and carcinogenic, which is a great threat to human bodies and the environment [1, 2].It has been reported that Cr is the third most important toxic …
Details
1. Introduction. Manufacturing of chromium products yields 6 million tons of soda ash chromite ore processing residue (COPR) annually (Zhang et al., 2022).Due to incomplete leaching of the material generated during production of Na 2 CrO 4 salt, the soda ash COPR contains approximately 1130–8500 mg/kg carcinogenic hexavalent …
Details
In the process of chromium salt production, large amount of chromite ore processing residues (COPR) are generated (Zhang et al., 2009, Brose and James, 2013, Kameswari et al., 2015). COPR comprises of water and acid soluble hexavalent chromium ions, which is highly mobile and its toxicity is far greater than relative stability of Cr 3+ ions.
Details
Commercial chromite ore beneficiation processes. Pure chromium is difficult to produce since it is readily contaminated by many other elements. Huge quantity of raw chromite ore is being mined and beneficiated in various chrome ore beneficiation plants throughout the world to cater the customized needs of various ferro alloy plants.
Details
Therefore, concentration of chromite is required. The most commonly used beneficiation methods for chromite ores are gravity separation, such as shaking table, jig, spiral, and Reichert cone ...
Details
Sofol is a well-known crusher and grinding mill manufacturer that offers equipment and solutions for customers from aggregates, mining and mineral grinding industry.
You can leave your message here, we'll send you an Email immediately.
Online ChatCopyright ©2000- 2024 Shanghai Sofol CompanySitemap
PE series jaw crusher is usually used as primary crusher in quarry production lines, mineral ore crushing plants and powder making plants.
GET QUOTE