• Leaching of chromite ore in concentrated KOH by

    CuO was used as a catalyst in the concentrated KOH solution to enhance the leaching of chromium from the chromite ore The impacts of temperature, KOHtochromite ore mass ratio, CuOtochromite ore mass ratio, and gas flow rate on the chromium leaching rate were investigated

  • Cited by: 2
  • Leaching of chromite ore in concentrated KOH by

    described as follows: chromite ore was oxidized in the submolten salt medium in the loop airlift reactor, after the leaching process, the slurry was diluted for the separation of K 2 CrO 4 and ferriteenriched residue; then the diluted alkaline solution was evaporated and concentrated for recycling The leaching of chromium

  • Leaching of hexavalent chromium from young

    Chromite ore processing residue (COPR) is a waste derived from the chromate extraction from roasted ores and is deposited in some countries in landfills The objective of this study was to investigate the leaching

  • Author: Katrin Matern, Harald Weigand, Ruben Kretzschmar, Tim Mansfeldt
  • A clean and efficient leaching process for chromite ore

    In order to improve the chromate salts cleaner production technology, a pressure leaching process for chromite ore in 50 wt% KOH solution was studied for the first time and the results were presented in this manuscript It was found out that the chromium extraction rate increased significantly with the increase of temperature and oxygen partial pressure, and the kinetics study confirmed that the leaching

  • Cited by: 16
  • (PDF) Leaching Mechanisms of Cr(VI) from Chromite

    Longterm leaching characteristics of chromium ore processing residue (COPR) (≈ 250 pore volumes of flow, PVF) was investigated using laboratory flowthrough column testing with synthetic

  • Leaching of Valuable Elements from the Waste

    The COPR from the calcium roasting process is the residue of water leaching after mixing chromite, sodium carbonate (Na 2 CO 3), and dolomite and calcining at high temperatures (15) This residue contains a large amount of calcium and a small amount of iron, aluminum, chromium, etc

  • Cited by: 1
  • Acid leaching of chromite ScienceDirect

    An alternative method for the production of chromium chemicals is leaching the chromite ore in alkali or acidic media Direct pressure leaching of chromite using sodium hydroxide (NaOH) was studied by Farrow and Burkin at a temperature range of 190 270

  • Cited by: 31
  • Preventing Chromium Leaching

    In this case, high chromium leachability is desired and is aided by the addition of lime to a mixture of chromite ore and Na2CO3 The CaONa2CO3 ore mixture is roasted at 1,100° to 1,150° C in an oxidizing air atmosphere, followed by water leaching of the roasted material to extract the chromium

  • Leaching Mechanisms of Cr(VI) from Chromite Ore

    The pH of the leaching solutions was adjusted to cover a wide range between 1 and 125 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)

  • Cited by: 40
  • Leaching of chromite ore in concentrated KOH by

    The results indicated that CuO played an important role in improving the chromium leaching rate The leaching rate reached 98% after leaching for 6 h when CuO was applied, whereas it was only 608% without CuO under the same reaction conditions: temperature 230 °C, KOHtoore mass ratio 6:1, stirring speed 700 r/min, gas flow rate 1 L/min

  • Leaching Of Chromium Ore westernriverranchmgde

    Leaching of chromium ore,Our company is a largescale heavy enterprise that taking heavy mining machinery manufactory as main products and integrated with scientific research, production, and marketing We are concentrating on producing and selling machines such as jaw crusher, cone crusher, hammer crusher, ball mill, sand maker, mobile crushing plant

  • Preventing Chromium Leaching

    The CaONa2CO3 ore mixture is roasted at 1,100° to 1,150° C in an oxidizing air atmosphere, followed by water leaching of the roasted material to extract the chromium as Na2CrO4 in solution The extract solution is acidified and purified, and the chromium is recovered by chromic acid electrolysis or by other means

  • Chromium leaching behavior in soil derived from

    To obtain information for the remediation design of chromium waste sites, the leaching behavior of chromium in chromiumcontaminated soil (Crsoil) derived from chromium ore processing residue (COPR) was investigated Batch leaching experiments were conducted using simulated rainwater as the leaching solution with pH adjusted to cover a range

  • Modeling Chromium Dissolution and Leaching from

    Chromium has been widely used in many industrial applications As a result of chromite ore processing, large amounts of chromite ore processing residue (COPR) material that can be classified as hazardous have been produced and released into the environment

  • Chromium leaching behavior in soil derived from

    Abstract To obtain information for the remediation design of chromium waste sites, the leaching behavior of chromium in chromiumcontaminated soil (Crsoil) derived from chromium ore processing residue (COPR) was investigated Batch leaching experiments were conducted using simulated rainwater as the leaching solution with pH adjusted to cover a range from 20 to 120 No Cr(VI) was detected in

  • Physical Chemistry of Roasting and Leaching

    Chromium is mainly used for the production of stainless steel, in electroplating, as pigments and in leather and refractory industries The natural resource of chromium is the chromite ore, which is a spinel (Fe 2+, Mg)[Cr,Al,Fe 3+] 2 O 4, and is often present with gangue minerals such silicates

  • Chromium remediation or release? Effect of iron(II

    Chromium remediation or release? Effect of iron(II) sulfate addition on chromium(VI) leaching from columns of chromite ore processing residue Geelhoed JS(1), Meeussen JC, Roe MJ, Hillier S, Thomas RP, Farmer JG, Paterson E Author information: (1)The Macaulay Institute, Craigiebuckler, Aberdeen, AB 8QH, UK

  • Getting to know leaching – Chromic

    Chromium (Cr), vanadium (V), molybdenum (Mo) and niobium (Nb) – the valuable metals for the CHROMIC project – need to be extracted by leaching too To see how, we should begin by saying that in a typical leaching operation there is a solid mixture (called “matrix”) from which the metal of interest (the “solute”) has to be dissolved

  • Chemical Engineering Journal EURELCO

    is very energy consuming, it is not applicable to lowgrade ore materials (such as the FeCr and SS slags) Alternatively, a hydrometallurgical method based on caustic soda leaching has been investigated for Cr recovery from chromite ore as well as chromium oxides [13] Indeed, chromium

  • Leaching of chromite ore in concentrated KOH by

    The results indicated that CuO played an important role in improving the chromium leaching rate The leaching rate reached 98% after leaching for 6 h when CuO was applied, whereas it was only 608% without CuO under the same reaction conditions: temperature 230 °C, KOHtoore mass ratio 6:1, stirring speed 700 r/min, gas flow rate 1 L/min

  • heap leaching of chromium ore Nettoyages

    heap leaching of chromium ore Remediation of Chromium‐Containing Soils by Heap Leaching The metals are removed by passing a special leaching solution through the ore In this study, the removal of Chromium (VI) from four New Mexico soils (sand, sandy loam, and clay) using heap leaching was evaluated at a column scale

  • Leaching Mechanism of Cr(VI) from Chromite Ore

    The leaching behavior of hexavalent chromium (Cr(VI)) and major metal elements relevant to Cr(VI) leaching from chromite ore processing residue (COPR) to HNO3 are investigated by batch leaching tests According to the test results, aqueous Cr(VI) accounted for 7080% of the content of total Cr Cr(VI) concentration was controlled by the dissolution degree of Cr(VI)bearing minerals (such as

  • Leaching Of Chromium Ore westernriverranchmgde

    Leaching of chromium ore,Our company is a largescale heavy enterprise that taking heavy mining machinery manufactory as main products and integrated with scientific research, production, and marketing We are concentrating on producing and selling machines such as jaw crusher, cone crusher, hammer crusher, ball mill, sand maker, mobile crushing plant

  • Modeling chromium dissolution and leaching from

    Chromium has been widely used in many industrial applications As a result of chromite ore processing, large amounts of chromite ore processing residue (COPR) material that can be classified as haz

  • USA Leaching of chromium, nickel, cobalt

    chromium ore nickel metals cobalt Prior art date 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 Lifetime Application number US25882A Inventor Courtney S Simons

  • Some studies on recovery of chromium from chromite ore

    enables leaching of more than 95% of chromium in COPR The method is selective to the lcachin2 of chromium a~ demonstrated by EDXRF measurements Leaching of chromium from COPR using peroxides leads ~l so to significmt reduction in particle size The reaction between residue and oxidant has been found to be biphasic

  • Reduction and immobilization of chromate in

    Chromite ore processing residue (COPR) poses a great environmental and health risk with persistent Cr(VI) leaching To reduce Cr(VI) and subsequently immobilize in the solid matrix, COPR was incubated with nanoscale zerovalent iron (nZVI) and the Cr(VI) speciation and leachability were studied Mul

  • Getting to know leaching – Chromic

    Chromium (Cr), vanadium (V), molybdenum (Mo) and niobium (Nb) – the valuable metals for the CHROMIC project – need to be extracted by leaching too To see how, we should begin by saying that in a typical leaching operation there is a solid mixture (called “matrix”) from which the metal of interest (the “solute”) has to be dissolved

  • Chemical Engineering Journal EURELCO

    is very energy consuming, it is not applicable to lowgrade ore materials (such as the FeCr and SS slags) Alternatively, a hydrometallurgical method based on caustic soda leaching has been investigated for Cr recovery from chromite ore as well as chromium oxides [13] Indeed, chromium

  • harga coal crushing plant crushing plant structure Manufacturer Of Cement In Gandhidham high capacity wet rod mill machine ball miller rock crusher manufacturers singapore marine engines for sale Ballast Crushing Equipment In Britain high gradient magnetic separator in the application of kaolin used stone crusher from japan fro sale large stone factory crusher rolo thered grianding matchine difference between eccentric and concentric plumbing fittings coal purchace mill in india High quality Jaw crusher Plant From canada cement silo lump crusher gp300 cone crusher for sale in sweden portable limestone cone crusher provider in malaysia crusher plant in chamarajanagar stone crushers photo of calcium carbonate used in materbatches 5w led track light coal mine belt conveyor standard steel idler rollers jm5 crusher whirl in mining ethiopia industrial crusher 08888888888 about quarry business in ethiopia sand cleaner filter construction used iron ore impact crusher suppliers minerals cone crusher Crushed stone for sale in Belgium crusherpanies south advertised clinker grinding mill on the market in belgium