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  • Hexavalent chromium removal by ferrochromium slag ...

    11/11/2005  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. A relatively small percentage of this material finds application, but the vast majority of ...

  • Cited by: 75
  • Hexavalent chromium removal by ferrochromium slag.

    11/11/2005  Hexavalent chromium removal by ferrochromium slag. Erdem M(1), Altundoğan HS, Turan MD, Tümen F. Author information: (1)Department of Environmental Engineering, Firat University, 23279 Elaziğ, Turkey. The aim of this study is to demonstrate the potential of Cr(VI) generation during jigging operation applied for ferrochrome recovery from slag. The Cr(VI) concentrations of water

  • Cited by: 75
  • 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. The effects of amount of acid, contact time, FS dosage, initial Cr(VI) concentration and temperature on the ...

  • Cited by: 75
  • ferrochrome slag trivalent and hexavalent chromium

    Key words: Speciation; Chromium; Ferrochrome slag; leaching ... Lind et al., (2001) and Pillay et al., (2003) indicated that there is gradual oxidation of trivalent to hexavalent chromium when the slag is exposed to atmospheric oxygen. Read More. Valuable waste - Mineral Processing. Summary: Ferrochrome industry waste, such as flue dust, contains chromite ... toxic nature of trivalent and ...

  • In situ bioremediation of hexavalent chromium in presence ...

    Stability of chromium in the ferrochrome slag dumps and leachate are affected by pH, redox potential and the presence of other metallic species in the slag. It is desirable to keep chromium in slag dumps in the trivalent [Cr(III)] state because trivalent chromium is 1000 times less toxic to living organisms than the hexavalent form [Cr(VI)]. Due to the low toxicity and low mobility of Cr(III ...

  • Cited by: 6
  • Environmental and technical assessment of ferrochrome

    1/12/2013  Chromium release from the ferrochrome slag limits its utilization/disposal. ... It exists in the common oxidation states of hexavalent chromium Cr(VI) and trivalent chromium Cr(III). While chromium as Cr(III) is less mobile and less harmful, Cr(VI) is highly leachable and extremely toxic under all environmental conditions. As per Occupational Safety Health Administration (OSHA) , the major ...

  • Cited by: 59
  • Hexavalent chromium in the recovery of ferrochromium

    1/10/1997  Hexavalent Cr is highly mobile, carcinogenic and toxic, Bartlet [7] has proposed a number of chemical methods for characterizing environmental chromium in soils. The products generated in the jigging operation were investigated by these methods to assess to what extent Cr(III) can be mobilized and oxidized, or Cr(VI) can be reduced in the environment. Gauglhofer and Bianchi [8] have listed ...

  • ferrochrome slag trivalent and hexavalent chromium

    Key words: Speciation; Chromium; Ferrochrome slag; leaching ... Lind et al., (2001) and Pillay et al., (2003) indicated that there is gradual oxidation of trivalent to hexavalent chromium when the slag is exposed to atmospheric oxygen. Read More. Valuable waste - Mineral Processing. Summary: Ferrochrome industry waste, such as flue dust, contains chromite ... toxic nature of trivalent and ...

  • Toxicity assessment and geochemical model of chromium ...

    However, toxic hexavalent chromium was released with maximum concentrations of 30 µg L(-1) and 18 µg L(-1) at L/S 10 and 100, respectively, during the earlier leaching stage. It concluded that the AOD slag possessed a certain leaching toxicity. After 10 d of leaching, trivalent chromium was the dominant species in the leachates, which corresponded to the results of PHREEQC simulation ...

  • Chromium Cr - PubChem

    Chromium compounds are both absorbed by the lung and the gastrointestinal tract. Oral absorption of chromium compounds in humans can range between 0.5% and 10%, with the hexavalent (VI) chromium more easily absorbed than the trivalent (III) form [L1982]. Absorption of chromium from the intestinal tract is low, ranging from less than 0.4% to 2.5% of the amount consumed [L1986].

  • INJECTION OF A FERROUS SULFATE/SODIUM DITHIONITE

    The hexavalent source area, consisting of slag and other solid wastes generated in the production of ferrochrome alloy, is located near a saltwater tidal marsh. A dissolved-phase hexavalent chromium plume, originating from the source area, is migrating toward the tidal marsh. Groundwater and aquifer solids in the source area are highly alkaline with groundwater pH values measured as high as 11 ...

  • JP4008723B2 - Hexavalent chromium treatment method ...

    hexavalent chromium cement chromium suspension step Prior art date 2002-03-11 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Active Application number JP2002065323A Other languages Japanese (ja) Other versions JP2003260465A (en Inventor 英一 勝

  • Product Chromium Sulphate

    Advantages of chromium sulphate plating over hexavalent chrome plating From a health standpoint hexavalent chromium is more toxic than the trivalent chromium sulphate Chromium sulphate coating gives higher cathode efficiency. Higher cathode efficiency leads to better throwing powder which gives very even and smooth plating in the corners and the surface. In trivalent plating anodes do not ...

  • Toxic and genotoxic effects of hexavalent chromium in ...

    23/09/2015  Chromium is one of the major inorganic environmental pollutants, which is added in the environment through various natural and anthropogenic activities and exists mainly in two forms: Cr(III) and Cr(VI). Cr(VI) is considered to be more toxic than Cr(III) due to its high solubility and mobility. It is a well-reported occupational carcinogen associated with lung, nasal, and sinus cancers. Thus ...

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

    18/12/2008  Naturally occurring chromium is usually present as trivalent Cr(III). Hexavalent Cr(VI) in the environment is almost totally derived from human activities [WHO 1990]. Air Contamination : According to the Toxics Release Inventory, in 1997, the estimated releases of chromium were 706,204 pounds to the air from 3,391 large processing facilities which accounted for about 2.2% of total ...

  • Toxicological Review of Trivalent Chromium (CAS No. 16065 ...

    (trivalent chromium), and +6 (hexavelent chromium) valence states. In the +3 valence state, the chemistry of chromium is dominated by the formation of stable complexes with both organic and inorganic ligands (Hartford, 1979). In the +6 valence state, chromium exists as oxo species such as CrO3 and CrO4 2-that are strongly oxidizing (Cotton and Wilkinson, 1980). Chromium in the ambient

  • ferrochrome slag trivalent and hexavalent chromium

    Key words: Speciation; Chromium; Ferrochrome slag; leaching ... Lind et al., (2001) and Pillay et al., (2003) indicated that there is gradual oxidation of trivalent to hexavalent chromium when the slag is exposed to atmospheric oxygen. Read More. Valuable waste - Mineral Processing. Summary: Ferrochrome industry waste, such as flue dust, contains chromite ... toxic nature of trivalent and ...

  • INJECTION OF A FERROUS SULFATE/SODIUM DITHIONITE

    The hexavalent source area, consisting of slag and other solid wastes generated in the production of ferrochrome alloy, is located near a saltwater tidal marsh. A dissolved-phase hexavalent chromium plume, originating from the source area, is migrating toward the tidal marsh. Groundwater and aquifer solids in the source area are highly alkaline with groundwater pH values measured as high as 11 ...

  • Chromium Compounds - US EPA

    Chromium occurs in the environment primarily in two valence states, trivalent chromium (Cr III) and hexavalent chromium (Cr VI). Exposure may occur from natural or industrial sources of chromium. Chromium III is much less toxic than chromium (VI). The respiratory tract is also the major target organ for chromium (III) toxicity, similar to chromium (VI). Chromium (III) is an essential element ...

  • Conversion of Chromium Ore Processing Residue to Chrome Steel

    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]. In the absence of information on the toxicity of hexavalent chromium, COPR was

  • Removal of hexavalent chromium in carbonic acid

    Hexavalent chromium (Cr(VI)) is well-known to be a strong oxidizer, and is recognized as a carcinogen. Therefore, it is regulated for drinking water, soil, groundwater and sea by the environmental quality standards all over the world. In this study, it was attempted to remove Cr(VI) ion in a carbonic acid solution by the oxidizing slag that was discharged from the normal steelmaking process in ...

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

    18/12/2008  Naturally occurring chromium is usually present as trivalent Cr(III). Hexavalent Cr(VI) in the environment is almost totally derived from human activities [WHO 1990]. Air Contamination : According to the Toxics Release Inventory, in 1997, the estimated releases of chromium were 706,204 pounds to the air from 3,391 large processing facilities which accounted for about 2.2% of total ...

  • Toxicological Review of Trivalent Chromium (CAS No.

    The most commonly occurring valence states are chromium metal (0), trivalent chromium (in), and hexavalent chromium (VI). Cr(in) potentiates the action of insulin in peripheral tissue and is essential for animals and humans. Adults in the United States are estimated to ingest approximately 60 ig/day of chromium from food (ATSDR, 1993). NRC has identified an ESADDI for chromium of 50-200 ig/d ...

  • Chromite (Cr2FeO4) FeCr2O4 - PubChem

    Chromite ore processing residue (COPR) containing measurable levels of hexavalent and trivalent chromium. [Cr(VI) and Cr(III), respectively] has been used to fill in low-lying areas in Hudson County, N.J. While it has been demonstrated that direct dermal contact with solutions containing Cr(VI) may elicit allergic contact dermatitis (ACD) in previously sensitized individuals, it is unknown to ...

  • 1988 OSHA PEL Project - Chromium Metal NIOSH CDC

    The Agency finds that the metallic form of chromium, ... which may be associated with exposure to metallic chromium is the frequent co-existence of the metallic form with both trivalent and hexavalent salts (Tr. p. 11-136). The Princi et al. study (1962, as cited in ACGIH 1986/Ex. 1-3, p. 139) reflects the problem of confounding exposures to which the AISI alludes. In this study, ferrochrome ...

  • JP3935251B2 - Treatment method for waste containing ...

    hexavalent chromium raw material treating containing waste cr Prior art date 1997-12-12 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired - Fee Related Application number JP34312797A Other languages Japanese (ja) Other versions JPH11169814A (en ...

  • Conversion of Chromium Ore Processing Residue to Chrome Steel

    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]. In the absence of information on the toxicity of hexavalent chromium, COPR was

  • Removal of hexavalent chromium in carbonic acid

    Hexavalent chromium (Cr(VI)) is well-known to be a strong oxidizer, and is recognized as a carcinogen. Therefore, it is regulated for drinking water, soil, groundwater and sea by the environmental quality standards all over the world. In this study, it was attempted to remove Cr(VI) ion in a carbonic acid solution by the oxidizing slag that was discharged from the normal steelmaking process in ...

  • Behavior of Hexavalent Chromium in a Polluted

    This work describes the chemical mechanisms governing transport and reduction of hexavalent chromium in soils of a contaminated industrial waste landfill. Groundwater and soil analyses indicate that the main source of chromium is a slag heap essentially consisting of mill tailings. In the groundwater, downstream migration of Cr(IV) is limited thanks to a redox mechanism involving chromate ions ...

  • Toxicological Review of Trivalent Chromium (CAS No.

    The most commonly occurring valence states are chromium metal (0), trivalent chromium (in), and hexavalent chromium (VI). Cr(in) potentiates the action of insulin in peripheral tissue and is essential for animals and humans. Adults in the United States are estimated to ingest approximately 60 ig/day of chromium from food (ATSDR, 1993). NRC has identified an ESADDI for chromium of 50-200 ig/d ...

  • RU2606005C1 - Method of producing modified

    Method of producing modified ferrochrome-lignosulphonate reagent involves creation in a reaction mass of lignosulphonate a redox system of Fe +2 and Cr 6+ and production of chromium and iron in trivalent form to form complexes with lignosulphonate and drying. Disclosed method includes adding to liquid technical lignosulphonate (II) sulphate, holding mass with mixing for 1.0 hour at temperature ...

  • JP3935251B2 - Treatment method for waste containing ...

    hexavalent chromium raw material treating containing waste cr Prior art date 1997-12-12 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired - Fee Related Application number JP34312797A Other languages Japanese (ja) Other versions JPH11169814A (en ...

  • 1988 OSHA PEL Project - Chromium Metal NIOSH CDC

    The Agency finds that the metallic form of chromium, ... which may be associated with exposure to metallic chromium is the frequent co-existence of the metallic form with both trivalent and hexavalent salts (Tr. p. 11-136). The Princi et al. study (1962, as cited in ACGIH 1986/Ex. 1-3, p. 139) reflects the problem of confounding exposures to which the AISI alludes. In this study, ferrochrome ...

  • KR101438713B1 - water treatment agent for separating ...

    The present invention relates to a water treatment agent for neutralizing hexavalent chromium in wastewater using acidic water and then reducing and reducing the water to insoluble trivalent chromium having low toxicity and mobility by using diluted water and a water treatment method using the water treatment agent, 500 to 1000 parts by weight of acidic water containing 0.015 to 0.030% by ...

  • (PDF) Chromite - ResearchGate

    tained from smelting ferrochrome are metal, slag, ... The toxic nature of trivalent and hexavalent Cr makes flue dust from the ferro- chrome industry hazardous. About 400 e 500 kg residue is ...

  • 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 Office of Air and Radiation Office of Air Quality Planning and Standards Research Triangle Park, North Carolina, NC 27711. This report has been reviewed by the Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency,