Optimisation of metal extraction from chromium ore processing residue in New Jersey, USA

Paustenbach, Dennis J., Deborah M. Meyer, Patrick J. Shee han, and Virginia Lau (1991). An assessment and quantitative uncertainty analysis of the health risks to workers exposed to chromium contaminated soils. Toxicol. Industrial Health. Millions of tons of chromite-ore processing residue have been used as fill in various locations in Northern New Jersey and else where in the United States. The primary toxicants in the residue are trivalent chromium [ Cr(III)] and hexavalent chromium [ Cr(VI)]. The hazard posed by Cr(III) is negligible due to its low acute and chronic toxicity. In contrast, Cr(VI) is considered a inhalation human carcinogen at high concentrations. Approxi mately 40 commercial and industrial properties in Northern New Jersey have been identified as containing chromite ore processing residue in the soil. One site, a partially-paved trucking terminal, was evaluated in this assessment. The arithmetic mean and geo metric mean concentrations of total chromium in soil were 977 and 359 mg/kg, respectively. The data were log-normal distrib uted. The arithmetic mean and geometric mean concentrations of Cr(VI) in surface soil were 37.6 and 3.1 mg/kg, respectively. The data could not be fit to a standard distribution, likely due to the large number of samples with concentrations below the method detection limit (65%). Dose was calculated for each exposure route using a Monte Carlo statistical simulation.

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Adsorption Characteristics and Transport Behavior of Cr(VI) in Shallow Aquifers Surrounding a Chromium Ore Processing Residue (COPR) Dumpsite

Journal of Chemistry ◽

10.1155/2019/4932837 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Yu Liu ◽

Yin Li ◽

Yucheng Hu ◽

Khan M. G. Mostofa ◽

Siliang Li ◽

...

Keyword(s):

Shallow Aquifer ◽

Column Experiments ◽

Silty Clay ◽

Shallow Aquifers ◽

Adsorption Characteristics ◽

Comprehensive Management ◽

Chromium Ore ◽

Transport Behavior ◽

Ore Processing ◽

Pseudo Second Order

This study explored the stratigraphic distribution and soil/shallow aquifer characteristics surrounding a chromium ore processing residue (COPR) dumpsite at a former chemical factory in China. Total Cr levels in top soils (5–10 cm) nearby the COPR dumpsite were in the range of 8571.4–10711.4 mg/kg. Shallow aquifers (1–6 m) nearby the COPR dumpsite showed a maximum total Cr level of 9756.7 mg/kg. The concentrations of Cr(VI) in groundwater nearby the COPR dumpsite were 766.9–1347.5 mg/L. These results display that the top soils, shallow aquifers, and groundwater of the study site are severely polluted by Cr(VI). Then, three aquifers (silt, clay, and silty clay), respectively, collected from the depth of 1.4–2.4 m, 2.4–4.8 m, and 4.8–11.00 m were first used to evaluate the adsorption characteristics and transport behavior of Cr(VI) in shallow aquifers by both batch and column experiments. The adsorption of Cr(VI) on tested aquifers was well described by pseudo-second-order equation and Freundlich model. The adsorption capacities of Cr(VI) on three aquifers followed the order: clay > silty clay > silt. The kinetics proved that Cr(VI) is not easily adsorbed by the aquifer mediums but transports with groundwater. Thermodynamics indicated that Cr(VI) adsorption on tested aquifers was feasible, spontaneous, and endothermic. Cr(VI) adsorption on tested aquifers decreased with increasing pH. Furthermore, the transport of Cr(VI) in adsorption columns followed the sequence of clay < silty clay < silt. Desorption column experiments infer that the Cr(VI) adsorbed on aquifers will desorb and release into groundwater in the case of rainwater leaching. Therefore, a proper treatment of the COPR and a comprehensive management of soils are vital to prevent groundwater pollution.

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Evaluation of Bimodal Water Retention Characteristics for Hydrating Chromium Ore Processing Residue (COPR)

Geo-Congress 2019 ◽

10.1061/9780784482124.076 ◽

2019 ◽

Author(s):

Mostafa Afzalian ◽

Jongwan Eun ◽

James M. Tinjum

Keyword(s):

Water Retention ◽

Chromium Ore ◽

Ore Processing ◽

Retention Characteristics

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Stabilization of chromium ore processing residue (COPR) with nanoscale iron particles

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2005.09.008 ◽

2006 ◽

Vol 132 (2-3) ◽

pp. 213-219 ◽

Cited By ~ 116

Author(s):

J CAO ◽

W ZHANG

Keyword(s):

Iron Particles ◽

Chromium Ore ◽

Ore Processing ◽

Nanoscale Iron Particles

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Conversion of Chromium Ore Processing Residue to Chrome Steel

GeoCongress 2008 ◽

10.1061/40970(309)48 ◽

2008 ◽

Cited By ~ 2

Author(s):

Jay N. Meegoda ◽

Wiwat Kamolpornwijit ◽

Zhengbo Hu ◽

Robert Mueller ◽

Ravi Patraju

Keyword(s):

Chrome Steel ◽

Chromium Ore ◽

Ore Processing

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Modifications to EPA Method 3060A to Improve Extraction of Cr(VI) from Chromium Ore Processing Residue-Contaminated Soils

Environmental Science & Technology ◽

10.1021/acs.est.7b01719 ◽

2017 ◽

Vol 51 (19) ◽

pp. 11235-11243 ◽

Cited By ~ 12

Author(s):

Christopher T. Mills ◽

Carleton R. Bern ◽

Ruth E. Wolf ◽

Andrea L. Foster ◽

Jean M. Morrison ◽

...

Keyword(s):

Contaminated Soils ◽

Chromium Ore ◽

Ore Processing

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Identification of Surface Processes in Individual Minerals of a Complex Ore through the Analysis of Polished Sections Using Polarization Microscopy and X-ray Photoelectron Spectroscopy (XPS)

Minerals ◽

10.3390/min8100427 ◽

2018 ◽

Vol 8 (10) ◽

pp. 427 ◽

Cited By ~ 2

Author(s):

Dhamelyz Silva-Quiñones ◽

Chuan He ◽

Melissa Jacome-Collazos ◽

Carsten Benndorf ◽

Andrew Teplyakov ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Complex Surface ◽

Extraction Process ◽

Metal Extraction ◽

Surface Processes ◽

Polarization Microscopy ◽

X Ray ◽

Ore Processing ◽

Oxidized Iron ◽

Powerful Approach

Understanding the changes of a mineral during ore processing is of capital importance for the development of strategies aimed at increasing the efficiency of metal extraction. This task is often difficult due to the variability of the ore in terms of composition, mineralogy and texture. In particular, surface processes such as metal re-adsorption (preg-robbing) on specific minerals are difficult to evaluate, even though they may be of importance as the re-adsorbed material can be blocking the valuable mineral and negatively affect the extraction process. Here, we show a simple yet powerful approach, through which surface processes in individual minerals are identified by combining polarization microscopy (MP) and X-ray photoelectron spectroscopy (XPS). Taking as an example a silver-containing polymetallic sulfide ore from the Peruvian central Andes (pyrite-based with small amounts of galena), we track the changes in the sample during the course of cyanidation. While polarization microscopy is instrumental for identifying mineralogical species, XPS provides evidence of the re-adsorption of lead on a pyrite surface, possibly as lead oxide/hydroxide. The surface of pyrite does not show significant changes after the leaching process according to the microscopic results, although forms of oxidized iron are detected together with the re-adsorption of lead by XPS. Galena, embedded in pyrite, dissolves during cyanide leaching, as evidenced by PM and by the decrease of XPS signals at the positions associated with sulfide and sulfate. At the same time, the rise of a lead peak at a different position confirms that the re-adsorbed lead species cannot be sulfides or sulfates. Interestingly, lead is not detected on covellite surfaces during leaching, which shows that lead re-adsorption is a process that depends on the nature of the mineral. The methodology shown here is a tool of significant importance for understanding complex surface processes affecting various minerals during metal extraction.

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