Contact Us

Hexavalent chromium removal by ferrochromium slag

Nov 11, 2005 The chromium content in slags is 2–12%, in oxide and metal form. The slag/metal amount ratio in smelting varies from 1.0 to 1.8, depending on raw materials . Slag is discarded as a waste material in enormous quantities during the ferrochrome production.

(PDF) Hexavalent chromium removal by ferrochromium slag

There is an in situ generation of ferrous sulphate by the effect of oxidizing agent and iron content of ferrochrome slag which is capable of reducing Cr(VI) to trivalent chromium.

Hexavalent Chromium NIOSH CDC

Jun 21, 2019 Hexavalent chromium (Cr(VI)) compounds are a large group of chemicals with varying properties, uses, and workplace exposures. Hexavalent chromium is harmful to the eyes, skin, and respiratory system. NIOSH considers all Cr(VI) compounds to be occupational carcinogens.

[PDF] Speciation of chromium in soils, plants and waste

This study assessed chromium pollution in soils, plants, water and slag from a ferrochrome smelting plant in Gweru, Zimbabwe. Speciation of chromium in plant leaves, soil and slag samples was carried out by selective leaching of Cr (VI) using a sodium carbonate leaching procedure prior to the spectrophotometric determination of Cr (VI). Total Cr and Cr (III) concentration in the samples were

Transport and fate of hexavalent chromium in slag–soil

Mar 28, 2019 The transport and fate of hexavalent chromium Cr(VI) in slag–soil system, which remain poorly understood, are of great importance for environmental risk assessment and pollution control of Cr(VI) in soil and groundwater. Based on the migration behavior of Cr(VI) in the chromium-containing slag under the effects of rainfall, the transport and fate of Cr(VI) in soil were investigated.

The toxicology of chromium with respect to its chemical

The cytotoxicity of soluble and insoluble hexavalent chromium compounds to fibroblasts is 100‐1000 times greater than that demonstrated by trivalent chromium compounds. In short‐term tests, the hexavalent chromium compounds demonstrated genotoxic effects four times more frequently than did the trivalent chromium compounds.

Hexavalent Chromium Factsheet

Hexavalent Chromium. What is hexavalent chromium? Hexavalent chromium is a form of the metallic element . chromium. Chromium is a naturally occurring element found in rocks, animals, plants, soil, and volcanic dust and gases. It comes in several different forms, including trivalent chromium and hexavalent chromium. Trivalent

Toxicological Review of Trivalent Chromium (CAS No. 16065

Chromium (Cr) is a metallic element belonging to the first transitional series of the periodic table. Elemental chromium has a CAS Registry Number of 7440-47-3. The three most stable forms in which chromium occurs in the environment are the 0 (metal and alloys), +3 (trivalent chromium), and +6 (hexavelent chromium) valence states.

Hexavalent Chromium Overview Occupational Safety and

Hexavalent chromium [Cr(VI)] is one of the valence states (+6) of the element chromium. It is usually produced by an industrial process. Cr(VI) is known to cause cancer. In addition, it targets the respiratory system, kidneys, liver, skin and eyes. Chromium metal is added to alloy steel to increase hardenability and corrosion resistance.

Chromium Compounds US EPA

Chromium is a naturally occurring element in rocks, animals, plants, soil, and volcanic dust and gases. (1) Chromium occurs in the environment predominantly in one of two valence states: trivalent chromium (Cr III), which occurs naturally and is an essential nutrient, and hexavalent chromium (Cr VI), which, along with

Hexavalent chromium removal by ferrochromium slag

The Cr(VI) concentrations of water contacted with ferrochromium slag (W/FS = 10) in a closed cycle after 50 batches were found as 0.61 mg/l. Also, reduction of Cr(VI) to Cr(III) and a subsequent precipitation of Cr(III) by using ferrochrome slag (FS) in a model solution has been aimed.

Transport and fate of hexavalent chromium in slag–soil

Mar 28, 2019 The transport and fate of hexavalent chromium Cr(VI) in slag–soil system, which remain poorly understood, are of great importance for environmental risk assessment and pollution control of Cr(VI) in soil and groundwater. Based on the migration behavior of Cr(VI) in the chromium-containing slag under the effects of rainfall, the transport and fate of Cr(VI) in soil were investigated.

Hexavalent Chromium Overview Occupational Safety and

Hexavalent chromium [Cr(VI)] is one of the valence states (+6) of the element chromium. It is usually produced by an industrial process. Cr(VI) is known to cause cancer. In addition, it targets the respiratory system, kidneys, liver, skin and eyes. Chromium metal is added to alloy steel to increase hardenability and corrosion resistance.

[PDF] Speciation of chromium in soils, plants and waste

This study assessed chromium pollution in soils, plants, water and slag from a ferrochrome smelting plant in Gweru, Zimbabwe. Speciation of chromium in plant leaves, soil and slag samples was carried out by selective leaching of Cr (VI) using a sodium carbonate leaching procedure prior to the spectrophotometric determination of Cr (VI). Total Cr and Cr (III) concentration in the samples were

The toxicology of chromium with respect to its chemical

The cytotoxicity of soluble and insoluble hexavalent chromium compounds to fibroblasts is 100‐1000 times greater than that demonstrated by trivalent chromium compounds. In short‐term tests, the hexavalent chromium compounds demonstrated genotoxic effects four times more frequently than did the trivalent chromium compounds.

Hexavalent Chromium niehs.nih.gov

May 14, 2020 Hexavalent chromium is a form of the metallic element chromium. Chromium is a naturally occurring element found in rocks, animals, plants, soil, and volcanic dust and gases. It comes in several different forms, including trivalent chromium and hexavalent chromium.

Hexavalent Chromium Is Carcinogenic to F344/N Rats and

May 01, 2009 Absorption of inorganic, trivalent and hexavalent chromium following oral and intrajejunal doses in rats. Acta Vet Hung 49:203-209 11402649. Crossref, Medline, Google Scholar; Food and Drug Administration. 1987. Good laboratory practice regulations. Final rule. 21 CFR 58. Fed Reg 52(172):33768-33782. Google Scholar

(PDF) In Situ Bioremediation of Chromium (VI) In a

PDF Stability of chromium in the tailing dumps and stockpiles of chromium concentrate at chrome mining fields is affected by pH, redox potential, and Find, read and cite all the research

Toxicological Review of Trivalent Chromium (CAS No. 16065

Chromium (Cr) is a metallic element belonging to the first transitional series of the periodic table. Elemental chromium has a CAS Registry Number of 7440-47-3. The three most stable forms in which chromium occurs in the environment are the 0 (metal and alloys), +3 (trivalent chromium), and +6 (hexavelent chromium) valence states.

Chromium (Cr) Toxicity: Where Is Chromium Found? ATSDR

Dec 18, 2008 Chromium waste slag containing potentially hazardous levels of Cr(VI) compounds was used as fill material at more than 160 residential, industrial, and recreational sites. Persons living or working in the vicinity of the sites may have been exposed through inhalation, ingestion, or skin contact with contaminated soils and dusts [Fagliano

1988 OSHA PEL Project Chromium Metal NIOSH CDC

The ACGIH has established an 8-hour TWA of 0.5 mg/m 3 for chromium, which is a steel-grey metal. In the final rule, OSHA is retaining the former 8-hour TWA PEL of 1 mg/m 3 for chromium metal. According to the ACGIH, a 0.5 mg/m 3 TLV-TWA for chromium “should be adequate to prevent pulmonary disease or other toxic effects” (ACGIH 1986/Ex. 1-3

Locating and Estimating Sources of Chromium

CHROMIUM L &E. EPA-450/4-84-007G July 1984 Locating and Estimating Air Emissions From Sources of Chromium U.S ENVIRONMENTAL PROTECTION AGENCY ferrochrome .. 43 13 Flow chart for production of chromium-containing basic brick by casting and pressing processes .. 55 14 Flow chart for production of chromic oxide bricks

Controlling Hexavalent Chromium Exposures during

Controlling hexavalent chromium levels • Product substitution. Use a less toxic substitute in place of Cr(VI). For example, trivalent chromium is less toxic than Cr(VI). There are a variety of alternatives available that provide similar characteristics to chrome electroplating. •

Product Chromium Sulphate

Product Overview Manufacturing Process Applications Specification Chromium Sulphate is an inorganic colouring compound with molecular formula Cr(OH)SO4.Basic chromium sulphates are the mixture of various chromic sulphates including chromium hydroxide sulphate Cr(OH)SO4. It is a water soluble compound and mostly used for leather tanning. It is the most efficient tanning agent.

The toxicology of chromium with respect to its chemical

The cytotoxicity of soluble and insoluble hexavalent chromium compounds to fibroblasts is 100‐1000 times greater than that demonstrated by trivalent chromium compounds. In short‐term tests, the hexavalent chromium compounds demonstrated genotoxic effects four times more frequently than did the trivalent chromium compounds.

[PDF] Speciation of chromium in soils, plants and waste

This study assessed chromium pollution in soils, plants, water and slag from a ferrochrome smelting plant in Gweru, Zimbabwe. Speciation of chromium in plant leaves, soil and slag samples was carried out by selective leaching of Cr (VI) using a sodium carbonate leaching procedure prior to the spectrophotometric determination of Cr (VI). Total Cr and Cr (III) concentration in the samples were

Conversion of Chromium Ore Processing Residue to Chrome

and 1150ºC under an oxidizing environment. Trivalent chromium in chromite ore was oxidized to hexavalent chromium. The highly soluble hexavalent chromium was then removed from the COPR (left over Chromium Ore Processing Residue) leaving un-oxidized trivalent chromium and slow-dissolving hexavalent chromium compounds [Burke et al., 1991].

Hexavalent Chromium Is Carcinogenic to F344/N Rats and

May 01, 2009 Absorption of inorganic, trivalent and hexavalent chromium following oral and intrajejunal doses in rats. Acta Vet Hung 49:203-209 11402649. Crossref, Medline, Google Scholar; Food and Drug Administration. 1987. Good laboratory practice regulations. Final rule. 21 CFR 58. Fed Reg 52(172):33768-33782. Google Scholar

Discovery, properties and applications of chromium and its

Feb 13, 2015 The basic properties of chromium are described, subsequently the discovery of chromium ores and the various methods of producing metallic chromium. How native chromium is formed and why the gemstone ruby has a connection to chromium are the following topics. The coordination of tri- and hexavalent chromium, hydrate isomerism, crystal field theory of CrIII and chromium

Locating and Estimating Sources of Chromium

CHROMIUM L &E. EPA-450/4-84-007G July 1984 Locating and Estimating Air Emissions From Sources of Chromium U.S ENVIRONMENTAL PROTECTION AGENCY ferrochrome .. 43 13 Flow chart for production of chromium-containing basic brick by casting and pressing processes .. 55 14 Flow chart for production of chromic oxide bricks

Chromium as an Environmental Pollutant: Insights on

Chromium exists in several oxidation states, but the most stable and common forms are Cr(0), the trivalent Cr(III), and the hexavalent Cr(VI) species. Cr(0) is the metallic form, produced in industry and is a solid with high fusion point usually used for the manufacturing of steel and other alloys.

Product Chromium Sulphate

Product Overview Manufacturing Process Applications Specification Chromium Sulphate is an inorganic colouring compound with molecular formula Cr(OH)SO4.Basic chromium sulphates are the mixture of various chromic sulphates including chromium hydroxide sulphate Cr(OH)SO4. It is a water soluble compound and mostly used for leather tanning. It is the most efficient tanning agent.

Chromium (Cr) Toxicity: Where Is Chromium Found? ATSDR

Dec 18, 2008 Chromium waste slag containing potentially hazardous levels of Cr(VI) compounds was used as fill material at more than 160 residential, industrial, and recreational sites. Persons living or working in the vicinity of the sites may have been exposed through inhalation, ingestion, or skin contact with contaminated soils and dusts [Fagliano

1988 OSHA PEL Project Chromium Metal NIOSH CDC

The ACGIH has established an 8-hour TWA of 0.5 mg/m 3 for chromium, which is a steel-grey metal. In the final rule, OSHA is retaining the former 8-hour TWA PEL of 1 mg/m 3 for chromium metal. According to the ACGIH, a 0.5 mg/m 3 TLV-TWA for chromium “should be adequate to prevent pulmonary disease or other toxic effects” (ACGIH 1986/Ex. 1-3

(PDF) Bioremediation of hexavalent chromium in soil microcosms

Hexavalent chromium is the major chromium species used in industry and hence is the common pollutant in a variety of industrial wastes, viz. sludge, fly ash, slag, etc.

Characterisation and liberation of chromium from fine

DOI: 10.1016/J.MINENG.2013.11.004 Corpus ID: 55734448. Characterisation and liberation of chromium from fine ferrochrome waste materials @article{Staden2014CharacterisationAL, title={Characterisation and liberation of chromium from fine ferrochrome waste materials}, author={Y. V. Staden and J. Beukes and P. Zyl and J. S. D. Toit and N. Dawson}, journal={Minerals Engineering},

Chromium Overview Occupational Safety and Health

Chromium is a steel gray, lustrous, hard metal extracted from chromite ores. In 2011, U.S. production of chromium was estimated at 160,000 metric tons, coming almost entirely from recycling stainless steel scraps. In addition, the U.S. imported 430,000 metric tons of chromium, primarily from South Africa, Kazakhstan, Russia and China. Chromium is valued for its high corrosion resistance and

Ageing of chromium(III)-bearing slag and its relation to

Slag arising in ferrochromium and stainless steel production is known to contain residual levels of trivalent chromium. As the chromium is normally bound in the slag matrix in various silicate or spinel phases, and hence not easily mobilised, utilisation or controlled disposal of such slag is generally considered unproblematic.