Preparation and Properties of Lanthanide Phosphates

2005 ◽  
Vol 284-286 ◽  
pp. 79-82 ◽  
Author(s):  
Regina Kijkowska ◽  
Racquel Z. LeGeros
Keyword(s):  
Phosphoric Acid ◽  
Acid Solution ◽  
Aqueous Solutions ◽  
Crystallization Process ◽  
Acidic Solution ◽  
Phosphoric Acid Solution ◽  
Precipitation Method ◽  
Crystalline Solids ◽  
Soluble Salts ◽  
Solubility Products

Lanthanide phosphates are known as slightly soluble salts with their solubility products ranging from 10-25 to 10-27. These phosphates can be obtained a) by precipitation from aqueous solutions of their salts using, for example, sodium or ammonium phosphates or b) by crystallization from boiling phosphoric acid solution. Application of crystallization in highly acidic solution instead of precipitation method yields highly crystalline solids of the composition of LnPO4.H2O (Ln: La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu and Y). This paper presents the effect of the acidity of the solution used for the crystallization process on crystallinity and morphology of EuPO4.H2O obtained: the higher the acidity of the solution the larger the crystals obtained. The morphology of the crystals changed from sphere-like particles crystallized in 2M H3PO4 to large hexagonal rods formed 2M H3PO4 with additional 0.4 M of HCl or HNO3.

Electropolishing of horizontal copper cylinders in unstirred phosphoric acid solution

1978 ◽  
Vol 7 (4) ◽  
pp. 313-318 ◽  
Author(s):  
I.A.S. Mansour ◽  
G.H. Sedahmed ◽  
M.Z. El-Abd ◽  
A.M. Ahmed
Keyword(s):  
Phosphoric Acid ◽  
Acid Solution ◽  
Phosphoric Acid Solution

Evaluation of environmentally friendly inhibitor for corrosion of mild steel in phosphoric acid solution: unconventional approach

2018 ◽  
Vol 65 (5) ◽  
pp. 506-514 ◽  
Author(s):  
Khalid Rashid ◽  
Anees Khadom
Keyword(s):  
Corrosion Rate ◽  
Phosphoric Acid ◽  
Acid Solution ◽  
Mild Steel ◽  
Design Method ◽  
Correlation Coefficients ◽  
Environmentally Friendly ◽  
Phosphoric Acid Solution ◽  
Content Type ◽  
Phenolic Components

PurposeThe purpose of this study is to investigate the corrosion inhibition of mild steel alloy in 2 M H3PO4solution by the pomegranate peel extract as a friendly inhibitor was studied at various temperatures, inhibitor concentrations and immersion times.Design/methodology/approachA weight loss method was used to evaluate the corrosion rate. The experimental Taguchi design method was used for the distribution of experiments. The experimental design gave results which were impossible to show graphically. However, this problem was solved effectively with the aid of regression analysis.FindingsCorrosion rate increased with temperature according to Arrhenius equation. It was found that the efficiency of inhibition was increased with an increase in the concentration of inhibitor and immersion time. However, this diminishes with increased temperature. According to Langmuir isotherm, the inhibitor was adsorbed physically on steel surface. The negative sign of estimated heat of adsorption suggests a stable spontaneous inhibition process. Combination of mathematical and statistical analysis was proposed to demonstrate the results of corrosion rate with high correlation coefficients. In addition, Fourier transform infrared spectrometer examinations confirmed that the organic inhibitor consists of phenolic components as main materials.Originality/valueUsing unconventional approach for evaluation of environmentally friendly inhibitor for corrosion of mild steel in phosphoric acid solution.

scholarly journals Electrochemical Oscillations during Electro-oxidation of Copper Anode in Phosphoric Acid Solution

2019 ◽  
Vol 87 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Lifeng DING ◽  
Peng WU ◽  
Jun CHENG ◽  
Yulan NIU ◽  
Zhengwei SONG ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Acid Solution ◽  
Phosphoric Acid Solution ◽  
Copper Anode ◽  
Electro Oxidation
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