scholarly journals Preparation of acid aluminum phosphate solutions for metakaolin phosphate geopolymer binder

RSC Advances ◽  
2021 ◽  
Vol 11 (51) ◽  
pp. 32258-32268
Author(s):  
Jean Noël Yankwa Djobo ◽  
Rachel Yanou Nkwaju
Keyword(s):  
Compressive Strength ◽  
Phosphoric Acid ◽  
Aluminum Phosphate ◽  
Molar Ratio ◽  
Phosphate Solutions ◽  
Geopolymer Binder

The acid aluminum phosphate solutions having the molar ratio Al/P of 1/3 are the most reactive and give rise to phosphate geopolymer with improved compressive strength. as compared to phosphate geopolymer obtained with pure phosphoric acid.

scholarly journals Geopolymers Based on Phosphoric Acid and Illito-Kaolinitic Clay

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
S. Louati ◽  
S. Baklouti ◽  
B. Samet
Keyword(s):  
Compressive Strength ◽  
Phosphoric Acid ◽  
Three Dimensional ◽  
Aluminum Phosphate ◽  
Molar Ratio ◽  
Calcined Clay ◽  
Modest Contribution ◽  
Maximum Value ◽  
Kaolinitic Clay ◽  
Xrd Patterns

New three-dimensional geopolymer materials based on illito-kaolinitic clay and phosphoric acid were synthesized. The effect of Si/P molar ratio on the geopolymers properties was studied. Raw, calcined clay, and geopolymers structures were investigated using XRD, IR spectroscopy, and SEM. The phosphoric acid-based geopolymers mechanical properties were evaluated by measuring the compressive strength. The Si/P molar ratio was found to increase with the increase of the compressive strength of the obtained geopolymers, which attained a maximum value at Si/P equal to 2.75. Beyond this ratio, the mechanical strength decreases. The XRD patterns of these geopolymers samples have proven that when the Si/P molar ratio decreases, the amorphous phase content increases. Besides, the structural analyses have revealed the presence of aluminum phosphate and Si-O-Al-O-P polymeric structure, whatever the Si/P molar ratio is (between 2.25 and 3.5). The obtained results have confirmed that the presence of the associated minerals such as hematite and quartz in the clay does not prevent the geopolymerization reaction, but the presence of illite mineral seems to have a modest contribution in the geopolymerization.

Calcium pyrophosphate powder synthesized from phosphoric acid and calcium carbonate

2020 ◽  
pp. 42-48
Author(s):  
Tatiana Safronova ◽  
◽  
Tatiana Shatalova ◽  
Snezhana Tikhonova ◽  
Yaroslav Filippov ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Phosphoric Acid ◽  
Functional Materials ◽  
Bone Defects ◽  
Thermal Conversion ◽  
Calcium Pyrophosphate ◽  
Molar Ratio

Powders of calcium pyrophosphate Ca2P2O7 in the form of γ- и β-modifications have been produced as a result of thermal conversion of brushite CaHPO4∙2H2O synthesized from phosphoric acid H3PO4 and calcium carbonate CaCO3 at the molar ratio P / Ca = 1.1. The resulting powders can be used for production of various functional materials including biocompatible and bioresorbable ones for the treatment of bone defects.

A novel separation method of the valuable components for activated clay production wastewater

2021 ◽  
Vol 19 (1) ◽  
pp. 530-540
Author(s):  
Lvshan Zhou ◽  
Tongjiang Peng ◽  
Hongjuan Sun ◽  
Dong Fu ◽  
Chuan Lai
Keyword(s):  
Aluminum Phosphate ◽  
Iron Phosphate ◽  
Acid Sites ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Precipitation Process ◽  
Iron Aluminum ◽  
Phosphorus Iron ◽  
Optimized Conditions ◽  
Acidic Wastewater

Abstract The acidic wastewater produced by the wet production of activated clay contains valuable components such as iron and aluminum. The precipitation method was successfully introduced to separate iron and aluminum from the activated clay production wastewater step by step, which can not only recover the valuable components, but also avoid environmental pollution. In the separation process, gypsum, iron aluminum phosphate, alumina, and sodium sulfate were prepared, and the phase compositions of separation products were analyzed by XRD and IR. The main influencing factors in the separation of iron and aluminum components were studied by single factor experiment. The results show that at the optimized conditions, phosphorus/iron molar ratio 6.0, the system pH 3.0, the reaction temperature 343 K, and the reaction time 90 min, the iron(iii) ion in the system can form a sodium-containing aluminum iron phosphate double salt, and the filtrate after separating Fe3+ and part of Al3+ can meet the requirements for forming high-purity Al2O3. During the phosphate precipitation process, the hypothesis should be correct that Al3+ reacts with PO 4 3 − {\text{PO}}_{4}^{3-} to form an AlPO4 skeleton, Fe3+ isomorphically replaces Al3+ in the [AlO4] tetrahedron, and adsorption occurs simultaneously, with Na+ occupying the terminal acid sites, P(Al)–OH.

scholarly journals Kinetic Modelling and Optimizing of Butyl Propionate over a Synthesied Material (Tungstan Phosphoric Acid) Heteropoly Catalyst Using Response Surface Technique

2021 ◽  
Vol 45 (4) ◽  
pp. 273-280
Author(s):  
Raju Kalakuntala ◽  
Srinath Surnani
Keyword(s):  
Experimental Data ◽  
Phosphoric Acid ◽  
Response Surface ◽  
Kinetic Modelling ◽  
Quadratic Model ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Response Surface Technique ◽  
Optimized Conditions ◽  
Surface Technique

The performance of heteropoly acid i.e., Tungstan phosphoric acid for the synthesis of butyl propionate at optimized conditions. Effect on conversion and yield of propionic acids using the Response Surface Methodology (RSM) were evaluated by different process parameters including catalyst loading, alcohol/acid molar ratio. There were no external and internal mass transmission limits. A quadratic model acquired by the variance study (ANOVA) has been shown to view experimental data successfully with the regression (R2 = 0.94 and R2 = 0.942) coefficients approaching to unity. The pseudo homogeneous kinetic model (PH) validated with experimental data to determine kinetic parameters i.e., activation energy (45.97 kJ/mol) and frequent factor (91319 L/mol-min).

Modeling the influence of chemical composition on compressive strength behavior of alkali-activated phosphorus slag cement using statistical design

2018 ◽  
Vol 45 (12) ◽  
pp. 1073-1083 ◽  
Author(s):  
Hamideh Mehdizadeh ◽  
Ebrahim Najafi Kani
Keyword(s):  
Compressive Strength ◽  
Chemical Composition ◽  
Statistical Design ◽  
Molar Ratio ◽  
Statistical Experimental Design ◽  
Molar Ratios ◽  
Strength Behavior ◽  
Optimum Chemical Composition ◽  
Optimum Chemical ◽  
Alkali Activated

In this study, a statistical experimental design based on response surface methodology (RSM) has been applied to predict and optimize the compressive strength of alkali-activated phosphorus slag in different ages (3, 7, and 28 days). For this purpose, the binder samples were prepared with different molar ratios of SiO2/Na2O (S/N), Na2O/Al2O3(Na/Al), and H2O/Al2O3(H/Al) as alkali activator. Results showed that S/N molar ratio plays its role in early ages of curing and Na/Al molar ratio, and showed its significant effect on 7 and 28 days of compressive strength. H/Al molar ratio had the most significant effect on compressive strength compared to the other parameters. The derived RSM models were statistically adequate and could be used to predict the compressive strength. The optimum chemical composition of activator to obtain the highest compressive strength was achieved as 0.39, 1.34, and 30 for S/N, Na/Al, and H/Al molar ratios, respectively, with compressive strength of 30, 65, and 100 MPa at 3, 7, and 28 days of curing.

Bonding in Aluminum Phosphate Ceramics Prepared At Low Temperatures

1987 ◽  
Vol 114 ◽  
Author(s):  
Michael R. Silsbee ◽  
D. M. Roy
Keyword(s):  
Phosphoric Acid ◽  
Low Temperatures ◽  
Aluminum Phosphate ◽  
Complete Understanding ◽  
Chemical Binding ◽  
Binding Agents ◽  
History Of ◽  
Alumino Silicate ◽  
Characterization Studies ◽  
History Of Use

ABSTRACTPhosphates have a long history of use as binding agents in ceramic systems. In particular the phosphate bonded alumina refractories and dental cements that employ the chemical reaction between a complex alumino-silicate glass and a buffered phosphoric acid to produce binding are among the most well known.The work described here has been undertaken in an effort to achieve a more complete understanding of the nature of the chemical binding in these materials.The results of a series of characterization studies on materials from the Al2O3-P2O5-H2O and SiO2-Al2O3-P2O5-H2O systems will be discussed with particular emphasis on the nature of the binding produced in these materials.

scholarly journals Effect of phosphoric acid content on the microstructure and compressive strength of phosphoric acid-based metakaolin geopolymers

Heliyon ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. e03853 ◽  
Author(s):  
Li Gao ◽  
Youxiong Zheng ◽  
Yan Tang ◽  
Jianwei Yu ◽  
Xingchang Yu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Phosphoric Acid ◽  
Acid Content

Research on the compressive strength of basic magnesium salts and cyanide slag solidified body

2018 ◽  
Vol 115 (2) ◽  
pp. 210
Author(s):  
Yubo Tu ◽  
Peiwei Han ◽  
Shufeng Ye ◽  
Lianqi Wei ◽  
Xiaomeng Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Molar Ratio ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Magnesium Salts ◽  
Solidified Body

The solidification of cyanide slag by using basic magnesium salts could reduce pollution and protect the environment. Experiments were carried out to investigate the effects of age, mixing amount of cyanide slag, water cement ratio and molar ratio of MgO to MgSO4 on the compressive strength of basic magnesium salts and cyanide slag solidified body in the present paper. It was found that compressive strength of solidified body increased with the increase of age, and decreased with the increase of mixing amount of cyanide slag and water cement ratio. The molar ratio of MgO to MgSO4 should be controlled in the range from 9 to 11 when the mixing amount of cyanide slag was larger than 80 mass%.

scholarly journals Metakaolinite Phosphate Cementitious Matrix: Inorganic Polymer Obtained by Acidic Activation

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 442 ◽  
Author(s):  
Antigoni Katsiki ◽  
Tobias Hertel ◽  
Tine Tysmans ◽  
Yiannis Pontikes ◽  
Hubert Rahier
Keyword(s):  
Compressive Strength ◽  
Optimum Composition ◽  
Molar Ratio ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Promising Candidate ◽  
Cementitious Matrix ◽  
Molar Ratios ◽  
Optimal Behavior ◽  
Amorphous Network

This work aims to study an aluminosilicate phosphate cementitious matrix. The cementitious matrix was studied on paste samples. The synthesis of metakaolinite phosphate cement (MKPC) was investigated using calorimetric techniques. A systematic study was performed by emphasizing a broad range of Al/P molar ratios, covering the different behavior of the material to the extremes, as well as the optimum composition. X-ray diffraction and scanning electron microscopy revealed that the final structure was mainly an amorphous network, albeit with some non-reacted phases. The compressive strength was studied on mortars using a cement/sand ratio of 1:3. MKPC specimens with Al/P ratios close to 1/1 showed optimal behavior. MKPCs with Al/P ratios above 1/1 were characterized by high porosity and low strength, whereas MKPCs with Al/P < 1 contained an excess of phosphates. The influence of the Al/P molar ratio on compressive strength was also studied, reaching a maximum of 68 MPa for the optimum composition. Based on the results, MKPC may be a promising candidate for construction purposes.

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