scholarly journals A Method of Synthesizing Lithium Hydroxide Nanoparticles Using Lithium Sulfate from Spent Batteries by 2-Step Precipitation Method

2020 ◽  
Vol 58 (4) ◽  
pp. 286-291
Author(s):  
Soyeong Joo ◽  
Hyun-Woo Shim ◽  
Jin-Ju Choi ◽  
Chan-Gi Lee ◽  
Dae-Guen Kim
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Lithium Hydroxide ◽  
Precipitation Method ◽  
Solution Temperature ◽  
Lithium Sulfate ◽  
Experimental Conditions ◽  
Mean Size ◽  
Enhance Efficiency

In this work, LiOH was synthesized using highly soluble Li2SO4. To enhance efficiency, this synthesis was performed using the precipitation method, and the correlation between each experimental condition and the synthesis of LiOH was investigated. The particle size and crystalline properties were tailored by controlling various experimental conditions, including the mole ratio of [Li]/[OH](Li: lithium sulfate, OH: barium hydroxide), reaction temperature, and reaction time. First, precursors with a ratio of 1:0.5 were reacted for 60 min at a solution temperature of 40 oC and filtered to remove precipitates. For the double reaction, half the hydroxyl precursor was added to the filtered solution and reacted under the same conditions. Using two-step precipitation, we were able to synthesize powder with a pure LiOH phase, a particle mean size of 100 nm, and purity over 99%.

Synthesis Parameters of Ultrafine YAG Powder Materials via Hydrothermal Precipitation Method

2018 ◽  
Vol 279 ◽  
pp. 99-103
Author(s):  
Ming Han Xu ◽  
Ai Xia Chen ◽  
Rui Hua Wang ◽  
Long Tao Liu ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Synthesis Parameters ◽  
Hydrothermal Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that when the molar ratio of salt to alkali that Y3+: OH- is 1:8, the more uniform morphology of the particles can be prepared, when the molar ratio of salt to alkali is increased, the morphology of the particles will not change. The reaction time is longer, the particle size will be thicker. The smaller the concentration of Y3+ ions is, the larger the particle size will be small. The experimental results show that the rod-like particles have a poly-crystal structure at the reaction temperature of 200°C, reaction time of 2 days and the molar ratio of salt to alkali of 1:8. The diameter of the rod-like particles is most of the powders have a particle size of 1000 nm and a small amount of powder has a particle size of about 5000 nm. The purity of powder is higher through the test of XRD.

Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

2020 ◽  
Vol 10 (2) ◽  
pp. 88-97
Author(s):  
Zafer Ekinci ◽  
Esref Kurdal ◽  
Meltem Kizilca Coruh
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Gas Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Conditions ◽  
Liquid Ratio ◽  
Positive Effects ◽  
Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

Reactive Adsorption Desulfurization of Thiophene in n-hexane over Oxides Adsorbent of NiO-ZnO/Al2O3-SiO2

2013 ◽  
Vol 455 ◽  
pp. 43-47 ◽  
Author(s):  
Xiao Ming Hou ◽  
Ben Xian Shen ◽  
Ji Gang Zhao
Keyword(s):  
Reaction Time ◽  
Structural Properties ◽  
Reaction Temperature ◽  
Chemical Process ◽  
Removal Rate ◽  
Precipitation Method ◽  
Initial Concentration ◽  
Reactive Adsorption ◽  
Adsorption Desulfurization ◽  
Co Precipitation

The oxides adsorbent of NiO-ZnO/-Al2O3-SiO2 was prepared by co-precipitation method. SEM, XRD and BET studies were performed to understand the structural properties of the adsorbent. And the adsorbent can be used for the desulfurization of thiophene in n-hexane as model gasoline. Removal rate of thiophene increased with increasing reaction time. Removal rate of thiophene in equilibrium decreases with increasing the initial concentration of thiophene. The extent of adsorption in adsorbent increased with increasing the initial concentration of thiophene. The removal rate of thiophene increases with increasing reaction temperature, it showed that the desulfurization is a chemical process not a physical process.

Enhanced Photocatalytic Performance and Mechanism of Ag3PO4 Particles Synthesized via a Sonochemical Process

2018 ◽  
Vol 10 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Chengxiang Zheng ◽  
Hua Yang ◽  
Yang Yang ◽  
Haimin Zhang
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Dye Degradation ◽  
Sonochemical Method ◽  
Simulated Sunlight ◽  
Spherical Nanoparticles ◽  
Direct Oxidation

A facile sonochemical method was used to synthesize Ag3PO4 particles and the effect of pH value, reaction temperature and reaction time on the products was investigated. It is found that the samples prepared at neutral (pH = 7) and alkaline (pH = 11) environments exhibit a similar particle morphology and size. The particles are shaped like spheres with a size distribution majorly focusing on a range of 200–450 nm, and the average particle size is about 300 nm. The sample prepared at acidic environment (pH = 3) is composed of polyhedral microparticles with size of 5–8 μm. At relatively low temperatures of 20–50 °C, the spherical nanoparticles do not undergo obvious morphology/size changes; however, when the temperature is increased up to 80 °C, the nanoparticles are aggregated to form large-sized polyhedral microparticles in the size range of 4–7 μm. Compared to the pH value and reaction temperature, the reaction time has a minor effect on the morphology of Ag3PO4 particles. RhB was chosen as the target pollutant to evaluate the photocatalytic activity of the as-prepared Ag3PO4 samples under simulated-sunlight irradiation. It is shown that the samples consisting of spherical nanoparticles exhibit an extremely high photocatalytic activity, and the degradation percentage of RhB after reaction for 50 min reaches over 90%. The samples of polyhedral microparticles have a relatively low photocatalytic activity, which is possibly due to their large particle size. Hydroxyl (.OH) radical was detected by spectrofluorimetry using terephthalic acid as a .OH scavenger and was not found to be produced over the simulated-sunlight-irradiated Ag3PO4 catalyst. The effect of ethanol, benzoquinone and ammonium oxalate on dye degradation was also investigated. Based on experimental results, the direct oxidation by h+ is suggested to the dominant mechanism toward the dye degradation.

Preparation of Nanosized Barium Titanate Powder by a Direct Reactive Precipitation Method

2013 ◽  
Vol 690-693 ◽  
pp. 454-457
Author(s):  
Hong Bo Li ◽  
Shu Yan Wu ◽  
Jing Wang ◽  
Chun Jie Li
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Surface Active Agent ◽  
Average Particle Size ◽  
Active Agent ◽  
Precipitation Method ◽  
Precipitation Process ◽  
Average Particle ◽  
Powder Particle Size ◽  
Powder Morphology

Columnar crystaldendriteequiaxial dendritescolumnar crystalNanosized powder was synthesized by direct-reactive precipitation process using a stoichiometrical mixture of TiCl4, BaCl2 as the reactants while NaOH as precipitant. Under the ratio of Ba to Ti is 1.02, PH=13, three reaction temperature of 70°C, 80°C and 90°C were conducted respectively. Morphology and phase structure of powder were investigated, and the influence of reaction temperature on powder morphology was discussed. The result indicates that synthesized powder is single cubic BaTiO3 and contains no impurities. BaTiO3 powders generally show spherical, and average particle size decreases with increasing reaction temperature. When reaction temperature is 80°C, BaTiO3 powder has best uniformity and dispersivity with the diameter of 80-100nm. The influence of reaction temperature on powder particle size can be attributed to the corporate contribution of nucleation and growth rate. Polyglycol as surface active agent has a significant effect in restraining agglomeration.

Study on the Preparation of Chitosan-Based Resin

2010 ◽  
Vol 160-162 ◽  
pp. 1810-1815
Author(s):  
Jing Xian Li ◽  
Juan Qin Xue ◽  
Ming Wu ◽  
Yu Jie Wang ◽  
Wei Bo Mao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Experimental Results ◽  
Raw Material ◽  
Cross Linking ◽  
Reactant Ratio ◽  
Experimental Conditions ◽  
Stirring Rate ◽  
Formaldehyde Crosslinking ◽  
New Type

With chitosan as the raw material, a new type of resin material is synthesized through formaldehyde crosslinking. The effects of the reactant ratio, the reaction temperature, the reaction time, the stirring rate and the system pH on the cross-linking rate are studied in detail. The resin material is then characterized by means of IR. The experimental results show that the reaction occurs mainly on the amino and the hydroxyl of chitosan. The chitosan-based resin material with good properties of sphericity and acidresistivity can be prepared under the optimal experimental conditions, which are found to be 1:5 for the ratio of chitosan and formaldehyde, 60°C for the temperature, 1 h for the reaction time, 440r/min for the stirring rate and 10 for the pH.

scholarly journals Investigating the zinc ion adsorption capacity of a chitosan/β-cyclodextrin complex in wastewater

2020 ◽  
Vol 143 ◽  
pp. 02006
Author(s):  
Jiaxin Liu ◽  
Siqi Wang ◽  
Xiuqing Ding ◽  
Jingyi Fu ◽  
Jun Zhao
Keyword(s):  
Reaction Time ◽  
Adsorption Capacity ◽  
Reaction Temperature ◽  
Zinc Ion ◽  
Mass Ratio ◽  
Industrial Waste Water ◽  
Cyclodextrin Complex ◽  
Experimental Conditions ◽  
Polyethylene Glycol 400 ◽  
Adsorption Rates

To decrease the amount of Zn2+ in industrial waste water, in this study, β-cyclodextrin (β-CD) was first modified and then used to obtain a β-cyclodextrin polymer (β-CDP). The effects of reaction temperature and reaction time of β-CD with citric acid (CA), polyethylene glycol 400 (PEG-400), and disodium hydrogen phosphate (NaH2PO4) on the amount of β-CDP produced were investigated. The results showed that at a reaction temperature of 145 °C and a reaction time of 4.5 h, 6.58 g of β-CDP was produced. Then, chitosan (CTS) was crosslinked with β-CDP using glutaraldehyde to prepare a chitosan/β-cyclodextrin (CTS/β-CDP) complex. The mass ratio of CTS to β-CDP, reaction temperature, reaction time, and amount of added glutaraldehyde were used as the main variables to examine the Zn2+ adsorption rate and adsorption capacity of the composites prepared in this study. The optimum experimental conditions were as follows: a mass ratio of 3:10, a reaction temperature of 80 °C, a reaction time of 90 min, and 2 mL of glutaraldehyde. Under these optimal conditions, the adsorption amount and adsorption rates of Zn2+ using CTS/β-CDP complex were respectively 97.70 mg·g-1 and 78.92%.

Preparating Arsenic Trioxide with Sulfuric Acid Wet Oxidation

2013 ◽  
Vol 662 ◽  
pp. 437-440
Author(s):  
Lin Zhuan Ma ◽  
Jun Ming Guo ◽  
Qiong Fang Cui ◽  
Man Hong Liu ◽  
Ying Jie Zhang
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Reaction Time ◽  
Arsenic Trioxide ◽  
Reaction Temperature ◽  
Extraction Yield ◽  
Wet Oxidation ◽  
Optimal Conditions ◽  
Concentrated Sulfuric Acid

The technology of the acidification is adopted to prepare arsenic trioxide (As2O3). With a concentration of 98% of concentrated sulfuric acid and Orpiment made into a certain ratio of the slurry suspension. Arsenic trioxide’s content is 99.94%, extraction yield can reach to 98.92%. The optimal conditions is reaction temperature at 120°Cand the reaction time in 2.5 h; the slurry ratio is less than 1/6 and particle size is less than 0.080 mm.

Magnesium Recovery from Desiliconization Slag of Nickel Laterite Ores by Carbonization

2013 ◽  
Vol 813 ◽  
pp. 255-258 ◽  
Author(s):  
Wen Ning Mu ◽  
Shuang Zhi Shi ◽  
Yu Chun Zhai
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Temperature Reaction ◽  
Nickel Laterite ◽  
Experimental Conditions ◽  
Solid Ratio ◽  
Carbonation Process ◽  
Laterite Ores ◽  
Orthogonal Experiments

This work examines the recovery of magnesium from desiliconization slag of nickel laterite ores by carbonation process. The effects of reaction temperature, reaction time, liquid/solid ratio and CO2 flow rate on magnesium dissolution are investigated. The optimized experimental conditions of recovering magnesium were gained by the analysis of orthogonal experiments.

A Novel Method of Leaching Vanadium from Extracted Vanadium Residue Using Sodium Sub-Molten Salt Medium

2011 ◽  
Vol 402 ◽  
pp. 253-260
Author(s):  
Lan Jie Li ◽  
Shi Li Zheng ◽  
Dong Hui Chen ◽  
Shao Na Wang ◽  
Hao Du ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Molten Salt ◽  
Reaction Temperature ◽  
Orthogonal Experiment ◽  
Salt Medium ◽  
Leaching Process ◽  
Novel Method ◽  
The Impact ◽  
Leaching Efficiency

Leaching of an extracted vanadium residue in sodium sub-molten salt medium was investigated. The significant effects of reaction temperature, particle size of residue, reaction time and NaOH-to-residue mass ratio on vanadium extraction were studied. By the orthogonal experiment study, it can be concluded that the impact order of factors is Tr> t>R according to the significance to the leaching process. Under conditions of reaction temperature 170°C, NaOH-to-residue 4:1, stirring speed 700 rpm, particle size -74 µm and reaction time around 180 min, leaching efficiency of vanadium obtained is higher than 90%. And, the leaching process of vanadium, with activation energy 27.69 kJ•mol-1, is controlled by the chemical reaction-controlled as the following rate equation. ln(1-x)=-kt

Sign in / Sign up

Export Citation Format

Share Document