scholarly journals Effect of ultrasound on the dissolution of Mardin-Mazıdağı (Turkey) phosphate ore in dilute H3PO4 solutions

2019 ◽  
Vol 51 (2) ◽  
pp. 164-167
Author(s):  
M. Sinirkaya
Keyword(s):  
Reaction Time ◽  
Phosphoric Acid ◽  
Surface Area ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Acid Solutions ◽  
Liquid Interfaces ◽  
Phosphate Ore ◽  
Increasing Temperature ◽  
Solid Liquid

The dissolution of phosphate ore in dilute phosphoric acid solutions was investigated in both the absence and presence of ultrasound. Acid concentration, reaction temperature and reaction time were chosen as parameters. While the conversion fractions decreased with increasing temperature in dilute phosphoric acid in absence of ultrasound, these rates increased with increasing temperature in the presence of ultrasound. In the experiments, the expected effects of ultrasound were observed, such as decrease in the thickness of the diffusion layer on the solid–liquid interfaces in the suspension, leading to increased surface area.

The Dissolution Kinetics of Tincal in Phosphoric Acid Solutions

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuksel Abali ◽  
Salih U Bayca ◽  
Ayse E Guler
Keyword(s):  
Particle Size ◽  
Phosphoric Acid ◽  
Dissolution Rate ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Dissolution Kinetics ◽  
Reaction Model ◽  
Acid Solutions ◽  
Liquid Ratio ◽  
Kinetics Of

In this study, the dissolution kinetics of tincal in phosphoric acid solutions was investigated. The effects of reaction temperature, acid concentration, solid to liquid ratio, particle size and stirring speed were determined in the experiments. The results showed that the dissolution rate increased with increasing acid concentration, reaction temperature, stirring speed and increased with decreasing particle size and solid to liquid ratio. The dissolution rate was found to be based on the first order pseudo homogenous reaction model. The activation energy of the tincal in phosphoric acid solution was determined as 42.28 kJ.mol-1.

Synthesis of Mesoporous Zr-P-Al Materials with High BET Specific Surface Area without Calcination

2011 ◽  
Vol 287-290 ◽  
pp. 2094-2101
Author(s):  
Zi Yu Liu ◽  
Yue Qi ◽  
Ying Xu Wei ◽  
Zong Bin Wu ◽  
Zhong Min Liu
Keyword(s):  
Phosphoric Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Long Range ◽  
Specific Surface Area ◽  
Acid Concentration ◽  
Long Range Order ◽  
Bet Specific Surface Area ◽  
Textual Data ◽  
Phosphoric Acid Concentration

A mesostructured zirconium oxide was synthesized hydrothermally using cetyltrimethylammonium bromide (CTAB) as the structure-directing agent and ZrSO4. 4H2O as the reactant. Subsequent post-synthetic treatment with H3PO4followed by the treatment with AlCl3solutions resulted in mesoporous Zr-P-Al materials, which exhibited high BET specific surface area before calcination. The phosphoric acid concentrationaffected the textual data of the resulting Zr-P and Zr-P-Al materials greatly. 0.1-0.5 M H3PO4increased obviously the long-range order of the as-synthesized Zr-P materials while 0.76 M H3PO4decreased it. After calcination at 773 K, the Zr-P materials turned to nonporous materials except the one synthesized by 0.5 M H3PO4, which showed micropores with a BET specific surface area of 147 m2/g. Further treating the Zr-P materials (synthesized from different concentration of phosphoric acid) with the same amount of AlCl3solution resulted in mesoporous Zr-P-Al materials, but the long-range order of which decreased when the H3PO4concentration increased. Similarly, the BET specific surface area of the above-mentioned Zr-P-Al materials decreased from 462 m2/g for 0.25 M H3PO4to 394 m2/g for 0.5 M H3PO4and finally to 332 m2/g for 0.76 M H3PO4after calcination at 773 K, while the pore size increased gradually from 3.0 to 3.5 nm. It was found that about 90% of the CTAB had been removed during the AlCl3treatment and that the as-synthesized Zr-P-Al materials exhibited high BET specific surface area as well as mesopores. The AlCl3amount is another factor affecting the textual data of the uncalcined Zr-P-Al materials besides the H3PO4concentration. With the phosphoric acid concentration of 0.25 M, the BET specific surface area of the as-synthesized Zr-P-Al materials increased from 477 m2/g to as high as 734 m2/g with the increasing AlCl3amount before it decreased from then on.

Solid-liquid extraction of Gd(III) and separation possibilities of rare earths from phosphoric acid solutions using Tulsion CH-93 and Tulsion CH-90 resins

2012 ◽  
Vol 30 (12) ◽  
pp. 1270-1275 ◽  
Author(s):  
S. Radhika ◽  
V. Nagaraju ◽  
B. Nagaphani Kumar ◽  
M. Lakshmi Kantam ◽  
B. Ramachandra Reddy
Keyword(s):  
Phosphoric Acid ◽  
Rare Earths ◽  
Liquid Extraction ◽  
Acid Solutions ◽  
Solid Liquid Extraction ◽  
Solid Liquid

Study on the Separation of Waste Polyester-Cotton Fiber with Dilute Acid

2011 ◽  
Vol 295-297 ◽  
pp. 2088-2091
Author(s):  
Wei Kong ◽  
Yong Ling Yu ◽  
Li Hua Lv
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Cotton Fiber ◽  
Mass Fraction ◽  
Orthogonal Experiment ◽  
Cotton Fibers ◽  
Dilute Acid ◽  
Liquid Ratio ◽  
Priority Order ◽  
Solid Liquid

Process of the separation of waste polyester-cotton fiber with dilute hydrochloric acid was studied. Acid mass fraction, reaction time, reaction temperature and solid-liquid ratio were studied on the effect of separation with the method of Orthogonal experiment. The results showed that the priority order of the factors was reaction time > acid mass fraction > reaction temperature > solid-liquid ratio. The optimal conditions through serious research on such factors were: acid mass fraction 10%, solid-liquid ratio 4g/100ml, reaction temperature 95°Cand reaction time 90 minutes. Through the microscope, polyester and cotton fibers were separated completely in which polyester into fibrous and cotton fibers were hydrolyzed into tiny powder.

Optimization of Nickel Chemical Extraction from Hazardous Residue

2016 ◽  
Vol 14 (1) ◽  
pp. 175-183 ◽  
Author(s):  
Mahdi Gharabaghi ◽  
Amirreza Azadmehr
Keyword(s):  
Reaction Time ◽  
Acid Concentration ◽  
Acid Leaching ◽  
Quadratic Model ◽  
Chemical Extraction ◽  
Liquid Ratio ◽  
Nickel Extraction ◽  
Process Factors ◽  
Solid Liquid ◽  
Significant Factors

AbstractStatistical design of experiments was used for design and analysis of nickel extraction from hazardous waste. Sulphuric acid leaching of zinc plant residue has been performed for monitoring and evaluating the effects of process factors on the nickel leaching yield. Factorial design was planned first in order to study the effect of six process factors and screen main variables. These factors were reaction time, acid concentration, solid-liquid ratio % (w/v), particle size, stirring speed and reaction temperature. The main factors and their interaction were studied by analysis of variance (ANOVA), and the results showed that the reaction time, acid concentration and solid-liquid ratio were the most significant factors. In the second set of experiments, response surface methodology (RSM) was used for modelling and optimisation of significant factors. Quadratic model was derived for the prediction of nickel extraction. The optimum values for maximum nickel was identified to be a leaching time of 30 min, acid concentration 10% (V/V) and solid liquid ratio of 10%. Using these optimum conditions, more than 94% nickel was extracted. In addition the results of model equation showed a good agreement with the experimental data.

Effect of Acidolysis Process on Viscosity of Cassava Starch

2013 ◽  
Vol 821-822 ◽  
pp. 1118-1121
Author(s):  
Yan Ming Zhang ◽  
Xiao Mei Wang
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Cassava Starch ◽  
Hydrochloric Acid Concentration ◽  
Mixing Effects

The cassava starch was firstly hydrolyzed using hydrochloric acid as the catalyst below the pasting point of starch, and then dried in the oven in order to get acid-hydrolyzed cassava starch, which would be used for the next size mixing. Effects of reaction time, temperature, and hydrochloric acid concentration on sizing liquor viscosity of acidolysis cassava starch were studied. The results show that, the viscosity of the acidolysis cassava starch decreases with the extension of reaction time, and it sharply declines before 60mins; the viscosity decreases with the increase of reaction temperature, and the change of viscosity is large when the reaction temperature of 40 °C increases to 45 °C; the viscosity decreases with the increase of hydrochloric acid concentration.

Synthesis and Dephosphorization of Iron Manganese Composite Oxide by Acid Leaching on Iron Manganese Ore

2012 ◽  
Vol 554-556 ◽  
pp. 489-493 ◽  
Author(s):  
Ting Ting Kang ◽  
Yi Liu ◽  
Yong Bing Huang ◽  
Jing Dong ◽  
Qian Huang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Removal Rate ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Manganese Ore ◽  
Composite Oxide ◽  
Iron Leaching ◽  
Solid Liquid ◽  
Iron Manganese

Fe-Mn composite oxide has been successfully synthesized using manganese ore in Guilin, Guangxi as an effective way to dephosphorize by acid leaching. Studied about the optimum conditions of acid leaching and the dephosphorization of Fe-Mn composite oxide. Process of the sulfuric acid concentration 2.1mol/L, solid-liquid ratio 1:4, reaction time 3.5h, the reaction temperature 90°C, the iron leaching rate of 66% while manganese 93%. Adsorption of phosphorus experiments showed that at oxide dosage 0.1000g, the reaction temperature 20°C, the reaction time 60min, pH 3.0, the phosphorus mass concentration 500ug/L in water sample, the phosphorus removal rate was up to 98.65%, compared to 70% removal rate of 0.5000g natural ore. The comparison of adsorption isotherms between Fe-Mn composite oxide and natural ore showed that in above conditions, the oxide's saturation adsorption quantity was 5.0000mg/g, improved 36.99 times.

Optimization of Silane-Silica OTR Compounds. Part 1: Variations of Mixing Temperature and Time during the Modification of Silica with Bis-(3-Triethoxisilylpropyl)-Tetrasulfide

1982 ◽  
Vol 55 (4) ◽  
pp. 967-989 ◽  
Author(s):  
S. Wolff
Keyword(s):  
Reaction Time ◽  
Natural Rubber ◽  
Reaction Temperature ◽  
Thermal Reaction ◽  
Cure Rate ◽  
Mixing Conditions ◽  
Optimum Reaction ◽  
And Performance ◽  
Increasing Temperature

Abstract This study of the TESPT modification reaction of silicas gives the compounder new and valuable information about rubber filler-silane interactions. It allows TESPT to be used more practically and economically. It also suggests several areas that would be interesting and worthwhile for further investigation. The conclusions based on this study are: (1) The modification reaction of silica with TESPT in situ cannot be considered as an equilibrium reaction. (2) The degree of modification increases with TESPT reaction time and temperature. Temperature has more effect than time. (3) In natural rubber, the highest and most practical modification reaction temperature is about 160°C. By performing the modification reaction between 150 and 160°C, it produces optimum cure rate and 300% modulus. Above 160°C, the thermal reaction of TESPT with natural rubber starts and reduces the sum of filler/rubber and rubber/rubber crosslinks available in the final cured rubber. (4) Up to 160°C, the number of filler/rubber and rubber/rubber crosslinks remains constant. But increasing temperature and reaction time lead to an increasing ratio of filler/rubber to rubber/rubber bonds. This improves the properties that are the most important for an OTR tread. (5) The higher the yield of filler/rubber bonds achieved by using the optimum reaction temperature and time, the less TESPT is necessary to get the desired properties. This produces better cost/performance. (6) To get the highest modification with TESPT, it should be added with the silica, to make best use of the reaction time dependency. (7) Most of the physical properties are dependent on the ratio of filler/rubber to rubber/rubber bonds and can simply be correlated to the 300% modulus of the compound. (8) The previously published standard mixing procedures' do not have to be changed with regard to the mixing sequence. However, by controlling mixing conditions, it may be possible to lower the level of TESPT and still obtain the desired improvements in compound physical and performance properties.

Research of Preparation of SO42-/TiO2-ZrO2 and its Application on Synthesis of Biodiesel from Waste Cooking Oil

2013 ◽  
Vol 316-317 ◽  
pp. 906-910 ◽  
Author(s):  
Hou Bo Zhou ◽  
Yang Cao ◽  
Jin Li
Keyword(s):  
Reaction Time ◽  
Surface Area ◽  
Reaction Temperature ◽  
Waste Cooking Oil ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Cooking Oil ◽  
Orthogonal Experiments ◽  
Optimum Reaction ◽  
Catalyst Dosage

SO42-/TiO2-ZrO2 was prepared by coprecipitation and dipping methods, and characterized by FT-IR, BET surface area measurement and NH3-TPD, and those results demonstrate the SO42- was loaded on the catalyst and the catalyst have enough surface area and pore size. The effect of methanol oil mole ratio, catalyst dosage, reaction temperature, reaction time on the conversion of waste cooking oil to biodiesel was investigated to find optimum reaction conditions. From the orthogonal experiments, the optimum reaction condition was shown as follows: methanol oil mole ratio is 25:1, catalyst dosage is 5% of oil, reaction temperature is 120°C, reaction time is 8h, the yield reached 96.68%.

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