ChemInform Abstract: Purification of Wet-Process Phosphoric Acid. X-Ray Data of a New Phase, MgAlF5. 1.5 H2O.

1986 ◽  
Vol 17 (46) ◽  
Author(s):  
M. FEKI ◽  
M. CHAABOUNI ◽  
H. F. AYEDI ◽  
J.-C. HEUGHEBAERT ◽  
G. BONEL
Keyword(s):  
Phosphoric Acid ◽  
X Ray ◽  
Wet Process ◽  
New Phase

Analysis of Wet-Process Phosphoric Acid and By-Product Filter Cake by X-ray Spectrometry

1984 ◽  
Vol 28 ◽  
pp. 221-226
Author(s):  
Wendell D. Wilhide ◽  
Doris H. Ash
Keyword(s):  
Phosphoric Acid ◽  
Calcium Sulfate ◽  
Filter Cake ◽  
Lithium Carbonate ◽  
Chemical Analyses ◽  
Element Analysis ◽  
X Ray ◽  
Wet Process ◽  
Control Precision ◽  
Preparation Techniques

AbstractRapid X-ray fluorescence (XRF) analytical methods have been developed for analyzing wet-process phosphoric acid liquid samples and by-product calcium sulfate filter-cake solids. Liquid acid samples are neutralized by lithium carbonate and pressed-pellet, dry sample wafers are prepared for a nine-element analysis. Filter-cake solids are dehydrated to anhydrous calcium sulfate for a ten-element analysis. Hovel sample preparation techniques are described which permit maximum use of the automated XRF system for process control. Precision obtained for typical materials is compared with results of conventional chemical analyses.

scholarly journals Studies on the transformation of calcium sulphate dihydrate to hemihydrate in the wet process phosphoric acid production

2012 ◽  
Vol 14 (2) ◽  
pp. 80-87 ◽  
Author(s):  
Barbara Grzmil ◽  
Bogumił Kic ◽  
Olga Żurek ◽  
Konrad Kubiak
Keyword(s):  
Phase Composition ◽  
Phosphoric Acid ◽  
Diffraction Analysis ◽  
Acid Production ◽  
Phosphate Rock ◽  
Calcium Sulphate ◽  
Industrial Plant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Process

Studies on the transformation of calcium sulphate dihydrate to hemihydrate in the wet process phosphoric acid production The influence of the process temperature from 85°C to 95°C, the content of phosphates and sulphates in the wet process phosphoric acid (about 22-36 wt% P2O5 and about 2-9 wt% SO42-) and the addition of αCaSO4·0.5H2O crystallization nuclei (from 10% to 50% in relation to CaSO4·2H2O) on the transformation of calcium sulphate dihydrate to hemihydrate has been determined. The wet process phosphoric acid and phosphogypsum from the industrial plant was utilized. They were produced by reacting sulphuric acid with phosphate rock (Tunisia) in the DH-process. The X-ray diffraction analysis was used to determine the phase composition and fractions of various forms of calcium sulphates in the samples and the degree of conversion of CaSO4·2H2O to αCaSO4·0.5H2O and CaSO4. It was found that the transformation of CaSO4·2H2O to αCaSO4·0.5H2O should be carried out in the presence of αCaSO4·0.5H2O crystallization nuclei as an additive (in the amount of 20% in relation to CaSO4·2H2O), at temperatures 90±2°C, in the wet process phosphoric acid containing the sulphates and phosphates in the range of 4±1 wt% and 27±1 wt%, respectively.

scholarly journals A new high-pressure polymorph of phosphoric acid

2017 ◽  
Vol 73 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
Craig L. Bull ◽  
Nicholas P. Funnell ◽  
Colin R. Pulham ◽  
William G. Marshall ◽  
David R. Allan
Keyword(s):  
High Pressure ◽  
Phosphoric Acid ◽  
Orthorhombic Phase ◽  
Void Space ◽  
Structural Behaviour ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Monoclinic Form ◽  
New Phase ◽  
Molecule Interaction

The high-pressure structural behaviour of phosphoric acid is described. A compression study of the monoclinic phase, using neutron powder diffraction and X-ray single-crystal diffraction, shows that it converts to a previously unobserved orthorhombic phase on decompression. Compression of this new phase is reported up to 6.3 GPa. The orthorhombic phase is found to be more efficiently packed, with reduced void space, resulting in a larger bulk modulus. Molecule–molecule interaction energies reveal a more extensive network of increased attractive forces in the orthorhombic form relative to the monoclinic form, suggesting greater thermodynamic stability.

High Temperature X-ray Diffraction Studies of the Defluorination Reactions of Chukhrovite, Falphite and Ralstonite

1984 ◽  
Vol 28 ◽  
pp. 339-343
Author(s):  
Robert L. Wilson ◽  
Jacob Mu ◽  
James L. Bradford
Keyword(s):  
Phosphoric Acid ◽  
Phosphate Rock ◽  
Fluoride Ion ◽  
Lower Grade ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Wet Process ◽  
New Process ◽  
Metallic Impurities

Current commercial processes for the production of wet-process phosphoric acid involve the dissolution of phosphate rock and separation of insoluble solids by filtration. Calcium is removed by the addition of H2SO4, to precipitate CaSO4•2H2O. Other metallic impurities are removed by extraction or precipitation.In a new process. Lower grade phosphate ore can be digested with recycled phosphoric acid. If the raw acid contains a fairly high concentration of Mg, it may be enriched in fluoride ion.

Quantitative X-Ray Diffraction Analysis of Calcium Sulfates and Quartz in Wet-Process Phosphoric Acid Filter Cakes

1985 ◽  
Vol 29 ◽  
pp. 211-216
Author(s):  
Kjell R. Waerstad
Keyword(s):  
Phosphoric Acid ◽  
Rapid Determination ◽  
Diffraction Method ◽  
Adhesive Tape ◽  
X Ray Diffraction ◽  
Synthetic Sample ◽  
X Ray ◽  
Wet Process ◽  
A New Technique ◽  
Filter Cakes

AbstractA quantitative X-ray diffraction method has been developed for rapid determination of the crystalline phases present in by-product filter cakes from wet-process phosphoric acid manufacture. A new technique to reduce preferred orientation of the crystallites by removing the top layer of the X-ray samples with adhesive tape is described, statistical analysis of synthetic sample mixtures of CaS04.2H2O, CaSO4 · 0.5H20, CaSo4, and α-Si02 indicates that the calcium sulfate phases present in typical filter cakes can be determined with an accuracy of about 3% at the 95% confidence level; quartz can be determined at about 14%. The method has been applied to the analysis of 10 filter-cake samples from an experimental hemihydrate plant. The results are in good agreement with data from X-ray fluorescence and chemical analyses

scholarly journals Pore Modification and Phosphorus Doping Effect on Phosphoric Acid-Activated Fe-N-C for Alkaline Oxygen Reduction Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1519
Author(s):  
Jong Gyeong Kim ◽  
Sunghoon Han ◽  
Chanho Pak
Keyword(s):  
Phosphoric Acid ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Electronic States ◽  
Nitrogen Adsorption ◽  
Reduction Reaction ◽  
Phosphorus Doping ◽  
X Ray ◽  
Precious Metal Catalysts ◽  
Adsorption Desorption

The price and scarcity of platinum has driven up the demand for non-precious metal catalysts such as Fe-N-C. In this study, the effects of phosphoric acid (PA) activation and phosphorus doping were investigated using Fe-N-C catalysts prepared using SBA-15 as a sacrificial template. The physical and structural changes caused by the addition of PA were analyzed by nitrogen adsorption/desorption and X-ray diffraction. Analysis of the electronic states of Fe, N, and P were conducted by X-ray photoelectron spectroscopy. The amount and size of micropores varied depending on the PA content, with changes in pore structure observed using 0.066 g of PA. The electronic states of Fe and N did not change significantly after treatment with PA, and P was mainly found in states bonded to oxygen or carbon. When 0.135 g of PA was introduced per 1 g of silica, a catalytic activity which was increased slightly by 10 mV at −3 mA/cm2 was observed. A change in Fe-N-C stability was also observed through the introduction of PA.

Flame Photometric Determination of Calcium in Wet-Process Phosphoric Acid

1954 ◽  
Vol 26 (6) ◽  
pp. 1060-1061 ◽  
Author(s):  
J. A. Brabson ◽  
W. D. Wilhide
Keyword(s):  
Phosphoric Acid ◽  
Photometric Determination ◽  
Wet Process

X-ray powder diffraction data for Ba3MnSi2O8—A new phase in the system BaO–MnO–SiO2

1996 ◽  
Vol 11 (1) ◽  
pp. 26-27 ◽  
Author(s):  
Irena Georgieva ◽  
Ivan Ivanov ◽  
Ognyan Petrov
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Data Interpretation ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Phase

A new compound—Ba3MnSi2O8 in the system BaO–MnO–SiO2 was synthesized and studied by powder X-ray diffraction. The compound is hexagonal, space group—P6/mmm, a=5.67077 Å, c=7.30529 Å, Z=1, Dx=5.353. The obtained powder X-ray diffractometry (XRD) data were interpreted by the Powder Data Interpretation Package.

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