Changes in physical structure and chemical composition of phosphate rock during calcination in fluidized and fixed beds

Özer, A. Kadir; Gülaboğlu, M. Şahin; Bayrakçeken, Samih; Weisweiler, Werner

doi:10.1163/156855206778440543

Cited by 20 publications

(12 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Microchemical speciation results: (A) Scanning electron microscope (SEM) images of MP‐1 (Main Plant Area) showing two phosphate minerals. The morphology and composition of the fluoride‐rich rough‐textured phosphate (lower right) is consistent with a secondary, calcined source (Ozer et al ). (B) Electron microprobe analysis (EMPA) images of realgar (AsS) in P1‐1.…”

Section: Resultssupporting

confidence: 73%

“…The second (bottom right) was roughed‐textured and contained calcium and fluoride in proportions indicative of fluorapatite. The morphology and composition of the latter is consistent with a secondary, calcined origin (Ozer et al ), which is potentially important because secondary precipitation of fluorapatite could lead to the sequestration of arsenic in process water and/or porewater. The other source sample selected for SEM/EDS analysis was P3‐2.…”

Section: Resultssupporting

confidence: 65%

See 1 more Smart Citation

Effectiveness of Monitored Natural Attenuation (MNA) as a Groundwater Remedy for Arsenic in Phosphatic Wastes

Bessinger¹,

Hennet²

2019

Groundwater Monitoring Rem

View full text Add to dashboard Cite

A study was conducted to evaluate monitored natural attenuation (MNA) as a remedy for arsenic in groundwater at a former phosphate mining and manufacturing facility. The mineralogy, speciation, and lability of arsenic in phosphatic wastes present in soils were characterized using sequential extraction procedures, leaching experiments, batch adsorption tests, and microchemical speciation analysis. A PHREEQC‐based reactive transport model was also parameterized using these laboratory results, and it was used to evaluate the importance of identified attenuation mechanisms on arsenic concentrations along a vertical flow path from a shallow, alluvial aquifer to the underlying Floridan aquifer. Arsenic was found to occur in several chemical forms in phosphatic wastes, including unstable sulfide minerals, adsorbed surface complexes, and relatively insoluble phosphate and oxide minerals. Most arsenic was associated with stable minerals. The reactive transport model predicted that historical leaching of solid‐phase waste materials in soils would not have generated enough arsenic to explain the concentrations observed in downgradient groundwater; instead, the source of arsenic to groundwater was likely acidic and saline process water that infiltrated though unlined ponds and ditches during historical manufacturing operations. A key factor affecting the long‐term effectiveness of natural attenuation of arsenic in groundwater is the occurrence and stability of iron oxyhydroxides in aquifer sediments. According to laboratory and reactive transport model results, sufficient levels were found to be present at the site to effectively limit arsenic migration at concentrations exceeding drinking water standards in the future in the Floridan aquifer. This study presents the geochemical evaluations that are needed to satisfy EPA guidelines on determining whether or not MNA is an acceptable remedy for a site. It specifically details the characterization and modeling that were used to demonstrate effectiveness at a site where MNA was ultimately selected as the remedy for arsenic in groundwater.

show abstract

Section: Resultssupporting

confidence: 73%

Section: Resultssupporting

confidence: 65%

Effectiveness of Monitored Natural Attenuation (MNA) as a Groundwater Remedy for Arsenic in Phosphatic Wastes

Bessinger¹,

Hennet²

2019

Groundwater Monitoring Rem

View full text Add to dashboard Cite

show abstract

“…Calcination is best carried out in fluidised beds from both technical and economic point of view. This is due to the numerous advantages of this technique especially the ease of material handling and the excellent thermal properties [6][7][8][9]. It has been observed that the calcination decreases the solubility and reactivity of the calcined phosphate rocks in the acidulent during the manufacture of phosphoric acid by the wet process [10].…”

Section: Introductionmentioning

confidence: 99%

Beneficiation of Mardin-Mazıdaği (Turkey) calcareous phosphate rock using dilute acetic acid solutions

Sengul

Özer

Gülaboğlu

2006

Chemical Engineering Journal

View full text Add to dashboard Cite

“…It seems that the RP sample was subdivided to many particles with different sizes. It was determined that the shrinkage and the cracks at the surrounding parts with phosphate occurring due to thermal and etching treatments [36]. The holes on the surfaces of the parts with phosphate prove that carbonate-fluorapatite was calcined and that the carbonate-fluorapatite changed to fluorapatite.…”

Section: Tem-edax Characterizationmentioning

confidence: 99%

Application of Gettering Process on the Improvement of the Structural and Mineralogical Properties of Tunisian Phosphate Rock

Daik¹,

Lajnef²

2016

J Material Sci Eng

View full text Add to dashboard Cite

The present study deals with the effects of gettering process on the structural and mineralogical composition of Tunisian phosphate rock. The treated samples were characterized to investigate the variation of physical structure and chemical composition as compared to the reference phosphate rock. The quantitative analysis of the impurities concentration before and after gettering treatment using energy-dispersive (EDX) reveals a significant reduction of impurity concentration (more than 75%) such as Al, Si, S, Na, and Mg. Scanning electron microscopy (SEM) shows that gettering process promoted structural alterations of phosphate rock sample due to fusion of impurities. The XRD patterns show that the chief mineral constituent of treated sample is only fluorapatite, while those in the reference ore were calcite, dolomite, quartz and carbonate-fluorapatite. FT-IR characterization show a disappearance of the bands related to calcite at 714 cm -1 as well as B carbonate situated at 1430 cm -1 , 1458 cm -1 after gettering treatment. This result is in good correlation with Raman analysis.

show abstract

Changes in physical structure and chemical composition of phosphate rock during calcination in fluidized and fixed beds

Cited by 20 publications

References 9 publications

Effectiveness of Monitored Natural Attenuation (MNA) as a Groundwater Remedy for Arsenic in Phosphatic Wastes

Effectiveness of Monitored Natural Attenuation (MNA) as a Groundwater Remedy for Arsenic in Phosphatic Wastes

Beneficiation of Mardin-Mazıdaği (Turkey) calcareous phosphate rock using dilute acetic acid solutions

Application of Gettering Process on the Improvement of the Structural and Mineralogical Properties of Tunisian Phosphate Rock

Contact Info

Product

Resources

About