Mohammad Al-Hwaiti

Beneficiation study of Eshidiya phosphorites using a rotary triboelectrostatic separator

Abstract This study was performed to investigate the feasibility of applying a Rotary Triboelectrostatic Separator (RTS) to the beneficiation of Eshidiya phosphate minerals. RTS separation tests were carried out on phosphatic bed A1, phosphatic bed A3 and slime samples. The bed A1 and slime samples were tested without desliming. Two sets of tests were performed using the A3 sample: one was performed without desliming and the other with the A3 sample deslimed. RTS separation tests as initially performed on the bed A1 and slime samples gave products that had essentially the same P2O5 content. This indicated that adsorbed clay particles on the phosphate surface are responsible for the poor separation of un-deslimed phosphates. Better triboelectrostatic separation was observed with the undeslimed A3 phosphate sample; these tests resulted in a highest product grade of 26% P2O5. The deslimed A3 sample showed far more effective separation than the undeslimed A3 one. In fact, a concentrate of 34% P2O5 was obtained from the triboelectrostatic separation of deslimed A3. The results indicate that with deslimed A3 P2O5 recovery was about 65% for a concentrate of 28% P2O5 and about 45% for a concentrate of 30% P2O5. These results clearly show the importance of desliming for effective beneficiation of phosphate by the RTS. A more efficient separation can be expected from optimized operating conditions and circuit configuration.

Selectivty Assessments of a Sequential Extraction Procedure for Potential Trace Metals’ Mobility and Bioavailability in Phosphate Rocks from Jordan Phosphate Mines

A modified six-step sequential extraction procedure was used to fractionate and determine the following trace metals: U4+, As5+, Cd2+, Cr+2, Cu2+, Ni2+, Pb2+, Zn2+, and V5+ in three different phosphate rocks from mines in Jordan. The mean values of uranium in the samples investigated were 98 ± 6 mgkg−1, 92 ± 3 mgkg−1, 215 ± 6 mgkg−1, and 159 ± 13 mgkg−1, respectively. The sequential extraction results obtained showed that most of the U4+ in these samples was strongly bound with 87%, 93%, 97%, and 93% of the total content, respectively, remaining in the samples after the sequential extraction steps were performed. Hence, 13%–7% and 3%–7%, respectively, of the U4+ is distributed in the most labile form, indicating that the majority of the U4+ in these samples was highly incorporated within the apatite present in the samples. The aforementioned was in agreement with the XRD and SEM-EDX results obtained. The apparent mobility of U4+, As5+, Cd2+, Cr+2, Cu2+, Ni2+, Pb2+, Zn2+, and V5+ (using all six extraction steps) from the Al-Abied and Al-Hasa samples was as follows: As5+ (30.17%)> Cu2+ (6.55%)> Zn2+(4.34%)> Cd2+ (3.84%) Cr+2 (3.66%)> Pb2+ (2.57%)> V5+ (53%)> Ni2+ (1.71%)> U4+ (0.99%). The mobility of As5+, Cd2+, Cu2+, Cr+2, Ni2+, Pb2+, U4+, Zn2+, and V5+ (using all six extraction steps) from Eshidiya samples was as follows: As5+ (17.32%)> Cr+2 (4.84%)> Zn2+ (4.25%)> Pb2+ (4.19%)> Cu2+ (3.49%)> V5+ (1.42%)> Cd2+ (0.78) U4+ (0.09%)> Ni2+ (0%).

Heavy metal contamination and health risk assessment in waste mine water dewatering using phosphate beneficiation processes in Jordan

Phosphate production is one of the major industries in Jordan. Phosphate beneficiation processing consume large quantities of its limited fresh water resources for processes such as washing and flotation. The process of mine water effluents have long been contained with remarkably high levels of heavy metals (e.g., Cd, Cr, Mn, Mo, Ni, Pb, U, V, and Zn), making them toxic for human health and surrounding environemnt. The main objective of this study was to determine the heavy metal contamination in washing mine water of phosphate bed-A1 (WMW-A1) and flotation mine water of phosphate bed-A3 (FMW-A3) of a Jordan phosphate mine (Eshidiya), to assess the health risks associated with oral daily intake and dermal absorption of mine water effluents from phosphate mining process. The results indicated accumulations of Cd, Cr, Li, Mn, Mo, Ni, Pb, U, V, and Zn in the mine water, with lower concentrations than the Jordan standards for discharge of water bodies into streams. In particular, Mn and Cr exhibited high levels of pollution in mine water due to their slightly higher contamination index values (CI). This can be interpreted to variation in geochemical behavior of these metal contents naturally present in francolite mineral phase. Varimax rotated factor analysis, cluster analysis, and correlation analysis revealed that Cd, Cr, Li, Mn, Mo, Ni, Pb, U, V, and Zn in mine water were mainly related to geochemical behavior for francolite mineral phase and clay mineral phase represents the main source of mine water contamination. The hazard quotient (HQ) and hazard index (HI) values were assessed to determine health risk (e.g., non-carcinogenic risk and cancer risk) in case of daily intake and dermal exposure pathways in mine water. The health risk assessment showed that As, Hg, Ni, Pb, and Zn are < 1, indicating non-carcinogenic risk tends to become significant for daily intake and dermal exposure pathways by the mine water. The cancer risk of being exposed to lead through WMW-A1 and FMW-A3 from these sources did not exceed the acceptable risk limits of 1:10,000 for regulatory purposes. Overall, this study provides comparative research on the accumulation, potential health risks and sources of heavy metals in mine water (washing and flotation) beneficiation process in Eshidiya mines, and our findings suggest that, Mn and Cr in both mine water could potentially represent environmental problems.

Distribution of potentially toxic metal and radionuclide contamination in soils related to phosphogypsum waste stockpiling in the Eshidiya Mine, Jordan

ABSTRACT Prior to this study, phosphogypsum (PG) stockpiles at the Eshidiya mine in Jordan were thought to be potentially enriched with potentially toxic metals and radionuclides, resulting in possible environmental degradation of the surrounding ecosystem. In order to investigate this phenomenon, enrichment levels and distribution patterns of metals (e.g. Zn, Cd, V) and radionuclides in the underlying soils, alluvium, and yellow marl bedrock were determined and compared against those in the PG stockpiles. The 226Ra, 210Pb, and 238U in soil reached peak concentrations of 1.5 pCi/g, 2.0 pCi/g, and 1.1 pCi/g, respectively. These elemental concentrations are similar to their concetrations in the uncontaminated soils, whereas the concentrations of these elements exhibit higher concentrations in PG and are as follows: 226Ra= 18 pCi/g, 210Pb= 19 pCi/g, and 238U= 4 pCi/g . The elements Cd, Zn, and V have maximum concentrations of 3 mg kg−1, 69 mg kg−1 and 62 mg kg−1, respectively, in the soils layer. These elemental concentrations are relatively lower than in uncontaminated soil and the PG. The degrees of mobility of the determined elements in soils were classified into three categories: elements with high mobility are Se, Mn, Pb, and Cr; those with moderate mobility are Co, Ni, As, Hg, Cu, V, and Zn; and those with low mobility are U, Cd, 210Pb, 226Ra, and 238U. Following correlation analysis, R-mode factor analysis was applied in conjunction with mineralogy to understand the geochemical variability of the soil. Four main meaningful factors were extracted: a detrital quartz factor, a clay minerals factor, a carbonate factor, and a terrigenous minerals factor. To investigate the spatial distribution patterns of the elements, a contour mapping technique was applied, allowing the following conclusions: (1) The elements 210Pb, 226Ra, and U exhibit similar distribution patterns; (2) Cd and Cu show similar distribution patterns; (3) As and V exhibit similar distribution patterns; and (4) no observed trend was observed for Cr. Generally, the results revealed that potentially toxic metals and radionuclides are not contaminated in soils related to the phosphogypsum stockpiles, and the soils of the Eshidiya area do not contain potentially toxic metals and radionuclide concentrations that threaten the surrounding ecosystem.