Ettringite-Induced Heave in Chromite Ore Processing Residue (COPR) upon Ferrous Sulfate Treatment

Dermatas, Dimitris; Chrysochoou, Maria; Moon, Deok Hyun; Grubb, Dennis G.; Wazne, Mahmoud; Christodoulatos, Christos

doi:10.1021/es0604461

Cited by 114 publications

(70 citation statements)

References 14 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The difference in Cr(VI) percentage obtained with alkaline digestion (16%) and XANES (34%) suggests that the alkaline digestion may underestimate the Cr(VI) content. The observation was in agreement with recent reports comparing the alkaline digestion and XANES analysis [26,27]. Therefore, the Cr(VI) content determined with XANES (19 490 mg kg −1 ) was used in the following bioaccessibility calculations.…”

Section: Copr Characterizationsupporting

confidence: 89%

Evaluation of chromium bioaccessibility in chromite ore processing residue using in vitro gastrointestinal method

Luo

et al. 2012

Journal of Hazardous Materials

View full text Add to dashboard Cite

a b s t r a c tIncidental ingestion of Chromite ore processing residue (COPR) particles poses a potential health risk. The purpose of this study was to determine the Cr bioaccessibility from COPR using the in vitro gastrointestinal (IVG) procedure. The bioaccessible Cr(VI) was 53.8% and 42.9%, respectively, in the gastric and intestinal phases from a total of 19 490 mg kg −1 Cr(VI) in COPR. Food intake including milk, dough, and ascorbic acid resulted in a significant decrease in Cr(VI) bioaccessibility. Some organic acids such as lactic, malic, and citric acid moderately reduced Cr(VI), while acetic acid exhibited no capacity for Cr(VI) reduction. The integrated area under the concentration-time curve (AUC) of the IVG extraction was used to calculate bioaccessibility. Compared with the bioaccessibility conventionally estimated using concentrations at the end of the extraction (CEP), the AUC technique should be implemented to confirm the accuracy of the IVG method when reduction of Cr(VI) occurs during the extraction. The absence of Cr(VI) phases in extracted residues as evidenced by XANES and XRPD analysis confirmed the Cr(VI) release and Cr(VI) reduction by food and ascorbic acid. With readily bioaccessible Cr(VI) and rapid human uptake, reduction of Cr(VI) might not be as effective a detoxification pathway as initially thought.

show abstract

Section: Copr Characterizationsupporting

confidence: 89%

Evaluation of chromium bioaccessibility in chromite ore processing residue using in vitro gastrointestinal method

Luo

et al. 2012

Journal of Hazardous Materials

View full text Add to dashboard Cite

show abstract

“…In a previous study, ettringite induced swelling was observed upon ferrous sulfate treatments (Dermatas et al 2006b;Moon et al 2007). However, the effects of lithification and initial dry density under unconfined swell conditions were not investigated.…”

Section: Introductionmentioning

confidence: 85%

“…The ferrous sulfate was applied to the ground surface and then mixed into the COPR using the rotating drum. The detailed mixing process has been explained in a previous publication (Dermatas et al 2006b). …”

Section: Experimental Methodologymentioning

confidence: 99%

Evaluation of ettringite-related swelling mechanisms for treated chromite ore processing residue

Moon

Wazne

Dermatas

et al. 2014

Environ Sci Pollut Res

Self Cite

View full text Add to dashboard Cite

Accelerated one-dimensional unconfined swell tests were conducted for ferrous sulfate chromite ore processing residue (COPR) field-treated samples. The field-treated samples were subjected to wet and dry cycles over 100 days to accelerate the lithification of the samples. Parallel laboratory experiments were performed to investigate the effects of mineralogy on COPR swell under controlled conditions. The field and laboratory samples were treated with ferrous sulfate at a ferrous-to-Cr(6+) molar stoichiometric ratios of eight (8×) and five (5×). X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) analyses were used to investigate the mineralogical changes upon treatment. The swell results indicated that significant COPR swelling was observed in all of the tested samples. The swelling was more pronounced in the 5× treated COPR sample than in the 8× treated COPR sample. Moreover, the laboratory-treated samples showed greater swelling behavior as compared with the field-treated samples, which was most probably due to the high dry density of the COPR, indicating that dry density was a more dominant factor than lithification. XRPD and SEM-EDX results confirmed that significant ettringite formation occurred in all treated samples.

show abstract

“…A lawsuit was enacted against the owner of a 34-acre site (denoted as SA7) on the Hackensack river in Jersey City, NJ, leading to the digging and hauling of 1.5 million tons of COPR. The site owner sought an alternative solution and initiated an extensive remedial investigation (Dermatas et al, 2006a and2006b). …”

Section: Introductionmentioning

confidence: 99%

Use of micro X-ray absorption spectroscopy and diffraction to delineate Cr(VI) speciation in COPR

Chrysochoou

Moon²,

Fakra³

et al. 2013

Issue 3

View full text Add to dashboard Cite

The speciation of Cr(VI) in Cromite Ore Processing Residue was investigated by means of bulk XRD, and a combination of micro-XRF, -XAS and -XRD at the Advanced Light Source (ALS), Berkeley, CA, U.S.A.. Bulk XRD yielded one group of phases that contained explicitly Cr(VI) in their structure, Calcium Aluminum Chromium Oxide Hydrates, accounting for 60% of the total Cr(VI). Micro-analyses at ALS yielded complimentary information, confirming that hydrogarnets and hydrotalcites, two mineral groups that can host Cr(VI) in their structure by substitution, were indeed Cr(VI) sinks. Chromatite (CaCrO 4 ) was also identified by micro-XRD, which was not possible with bulk methods due to its low content. The acquisition of micro-XRF elemental maps enabled not only the identification of Cr(VI)-binding phases, but also the understanding of their location within the matrix. This information is invaluable when designing Cr(VI) treatment, to optimize release and availability for reduction.

show abstract

Ettringite-Induced Heave in Chromite Ore Processing Residue (COPR) upon Ferrous Sulfate Treatment

Cited by 114 publications

References 14 publications

Evaluation of chromium bioaccessibility in chromite ore processing residue using in vitro gastrointestinal method

Evaluation of chromium bioaccessibility in chromite ore processing residue using in vitro gastrointestinal method

Evaluation of ettringite-related swelling mechanisms for treated chromite ore processing residue

Use of micro X-ray absorption spectroscopy and diffraction to delineate Cr(VI) speciation in COPR

Contact Info

Product

Resources

About