X-ray diffraction and fluoride analysis of enamel powder treated with concentrated phosphoric acid containing sodium fluoride

1980 ◽  
Vol 7 (6) ◽  
pp. 471-474 ◽  
Author(s):  
I. GEDALIA ◽  
H. BAHAREV ◽  
D. KOCHAVI
Keyword(s):  
Phosphoric Acid ◽  
Sodium Fluoride ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Mineralogical stabilization of Ternesite in Belite Sulfo-Aluminate Clinker elaborated from limestone, shale and phosphogypsum

2018 ◽  
Vol 149 ◽  
pp. 01073
Author(s):  
K. Ben Addi ◽  
A. Diouri ◽  
N. Khachani ◽  
A. Boukhari
Keyword(s):  
Infrared Spectroscopy ◽  
Phosphoric Acid ◽  
Portland Cement ◽  
Stability Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

This paper investigates the mineralogical evolution of sulfoaluminate clinker elaborated from moroccan prime materials limestone, shale and phosphogypsum as a byproduct from phosphoric acid factories. The advantage of the production of this type of clinker is related to the low clinkerisation temperature which is known around 1250°C, and to less consumption quantity of limestone thus enabling less CO2 emissions during the decarbonation process compared to that of Portland cement. In this study we determine the stability conditions of belite sulfoaluminate clinker containing belite (C2S) ye’elimite (C4A3$) and ternesite (C5S2$). The hydration compounds of this clinker are also investigated. The monitoring of the synthesized and hydrated phases is performed by X-Ray Diffraction and Infrared spectroscopy. The results show the formation of ternesite at 800°C and the stabilization of clinker containing y’elminite, belite and ternesite at temperatures between 1100 and 1250°C.

Characterization of silica polymorphs in kaolins by X-ray diffraction before and after phosphoric acid digestion and thermal treatment

2005 ◽  
Vol 552 (1-2) ◽  
pp. 201-206 ◽  
Author(s):  
Sibel Kahraman ◽  
Müşerref Önal ◽  
Yüksel Sarıkaya ◽  
İhsan Bozdoğan
Keyword(s):  
Thermal Treatment ◽  
Phosphoric Acid ◽  
Acid Digestion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After

Preparation and Characterization of A Composite Obtained through Ti (IV) and Phosphoric Acid

2014 ◽  
Vol 775-776 ◽  
pp. 97-101
Author(s):  
Loanda Raquel Cumba ◽  
U.O. Bicalho ◽  
D.R. Carmo
Keyword(s):  
Phosphoric Acid ◽  
Titanium Isopropoxide ◽  
Deionized Water ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopies ◽  
Prepared Material ◽  
Scanning Electron

This paper describes the preparation and complementary characterization of a composite formed from the activation of titanium isopropoxide by phosphoric acid and deionized water (TiP).Techniques such as, X-ray diffraction (XRD), Raman , electronic (UV-vis) and Scanning electron microscopies (SEM) were used for characterization of this new composite formed. In the X-ray diffractogram of TIP was observed four intense peaks. A strong absorption was observed in the region 362-445 nm. The scanning electron microscopy of TiP, shows that the prepared material consists mostly of a cluster of spherical particles with diameters ranging from 2.35 to 2.60 μm.

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.

Behaviour of Cement CEM III / B under Acid Solutions Agression (I)

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Ion Teoreanu ◽  
Alice Pop2 ◽  
Mariana Coarna ◽  
Daniela Natac
Keyword(s):  
Compressive Strength ◽  
Chemical Composition ◽  
Phosphoric Acid ◽  
Acid Solution ◽  
Acid Corrosion ◽  
Point Of View ◽  
Acid Solutions ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
X Ray

This paper aims at investigating the behaviour of a type CEM III/B cement under acid corrosion with formation of insoluble products. Cement paste and mortar specimens have been cured in sulphuric acid and phosphoric acid solutions. The samples have been kept in water up to 28 days and further 180 days in 0.5 mol/L acid solutions. At specific terms, the samples underwent compressive strength, chemical and X-ray diffraction analysis. The tests� results pointed out significant differences of chemical composition between the corrosion layers and the uncorroded core. The corrosion products formed in each acid solution were identified. In concretes with composite, ecologic cements the corrosion noticed on the cement pastes can be avoided. For that purpose during the preparation of the concretes there have to be achieved a high compactness and, consequently, a high impermeability. The binder matrix of the concrete is therefore, performing from the point of view of the resistance against the acid corrosion.

scholarly journals Corrosion inhibition of austenitic stainless steel by clay in polluted phosphoric acid with presence of SiC abrasif

2018 ◽  
Vol 149 ◽  
pp. 01049 ◽  
Author(s):  
S. Skal ◽  
Y. Kerroum ◽  
Y. El Aoufir ◽  
A. Guenbour ◽  
A. Bellaouchou ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Phosphoric Acid ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Corrosion Damage ◽  
Electrochemical Process ◽  
Solid Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Corrosive Environments

Stainless steels have many properties mechanical and chemical resistances resulting from the formation of the protective layer (passive film) on their surface which prevents the metal to react with corrosive environments such as, phosphoric acid. This acid contains various impurities, including agressive agents and solid particles of gypsum, increase the risk of corrosion damage depending on the type of stainless steel used. In addition, it has been show that abrasion-corrosion causes an acceleration electrochemical process leading to a decrease in the resistance of materials. This work is to find a solution through an ecological inhibitor. That why we have been studied the effect of crude clay on corrosion behavior of Alloy 31 in polluted phosphoric acid with abrasive by electrochemical impedance spectroscopy (EIS) . The clay was characterized by X-ray fluorescence spectroscopy (FX), X-ray diffraction (DRX) and infrared spectroscopy (IR). EIS exhibited that resistance of Alloy 31 increased with increase the concentration of inhibitor.

Pyromorphite formation and stability after quick lime neutralisation in the presence of soil and clay sorbents

2007 ◽  
Vol 4 (2) ◽  
pp. 109 ◽  
Author(s):  
Mark A. Chappell ◽  
Kirk G. Scheckel
Keyword(s):  
Phosphoric Acid ◽  
Contaminated Soils ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Natural Soil ◽  
X Ray Diffraction ◽  
Quick Lime ◽  
X Ray ◽  
Soil Systems ◽  
Diffraction Patterns

Environmental context. Questions remain regarding the potential risk of human Pb exposure from metal-contaminated soils. Studies show that the risk of human exposure is more accurately linked to the toxicity of the Pb species in soil than the total quantity of Pb. This work explores the practicality of converting Pb to a less toxic, less bioavailable species called pyromorphite in the presence of soil. Abstract. Soluble Pb is immobilised in pure systems as pyromorphite by adding sources of P, but doubts remain about the effectiveness of this approach in natural soil systems, particularly given the ability of soil humic substances to interfere with Pb-mineral formation. In addition, recent thermodynamic modelling predicts that pyromorphite formed by the addition of phosphoric acid to Pb-contaminated soils, followed by neutralisation with quick lime (Ca(OH)2) will destabilise the mineral, reverting the Pb back to more soluble species such as cerussite or anglesite. In this paper, we describe experiments to form pyromorphite in the presence of two different sorbents: a reference smectite called Panther Creek Bentonite, and a commercially available, organically rich potting mixture. We present X-ray diffraction (XRD) evidence suggestive of pyromorphite formation, yet, like similar studies, the evidence is less than conclusive. Linear combination fits of Pb X-ray absorption fine-structure spectroscopy (XAFS) data collected at the Advanced Photon Source at Argonne National Laboratory show that pyromorphite is the major Pb species formed after the addition of phosphoric acid. Furthermore, XAFS data shows that neutralising with quick lime enhances (as opposed to reducing) pyromorphite content in these systems. These results call into question relying solely on XRD data to confirm or deny the existence of minerals like pyromorphite, whose complex morphology give less intense and more complicated diffraction patterns than some of the simpler Pb minerals.

Synthesis of Porous Anodic Alumina (PAA) on Aluminum Alloy AA6061 in Mixture of Phosphoric Acid and Oxalic Acid

2016 ◽  
Vol 857 ◽  
pp. 237-241
Author(s):  
Chun Hong Voon ◽  
Bee Ying Lim ◽  
K.L. Foo ◽  
Uda Hashim ◽  
Sung Ting Sam ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Oxalic Acid ◽  
Phosphoric Acid ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interpore Distance ◽  
Diffraction Patterns ◽  
Ordered Porous

In this study, porous anodic alumina was formed on aluminum alloy AA6061 by anodizing using mixture of 0.3 M oxalic acid and phosphoric acid with concentration ranged from 0.1 M to 1.0 M. AA6061 alloys were anodized at 40 V and 25°C for 60 minutes. FESEM images show that the uniformity of the pores arrangement of porous anodic alumina decreased with the increasing concentration of phosphoric acid in the electrolyte. Well-ordered porous anodic alumina was formed in mixture of 0.3 M oxalic acid and 0.1 M phosphoric acid while disordered porous anodic alumina were formed when the concentration of phosphoric acid were in the range of 0.3 M to 1.0 M. Pore size and interpore distance were found to increase with the concentration of phosphoric acid in the mixture. X-ray diffraction patterns show that to γ-Al2O3 were formed on the surface of AA6061 after the anodizing process, regardless of the concentration of phosphoric acid in the mixture electrolyte.

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