Research on Controllable Synthesis of Magnesium Carbonate Tri-Hydrate

2014 ◽  
Vol 525 ◽  
pp. 35-39 ◽  
Author(s):  
Dan Wu ◽  
Bi Jun Luo ◽  
Yu Qi Wang ◽  
Shao Yan Lu ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Ph Value ◽  
Raw Materials ◽  
Salt Lake ◽  
Magnesium Carbonate ◽  
X Ray Diffraction ◽  
Hydrogen Carbonate ◽  
Average Aspect Ratio ◽  
Ammonium Hydrogen ◽  
Settling Performance ◽  
Salt Lake Brine

In order to promote the comprehensive utilization of salt lake brine resources, magnesium carbonate tri-hydrate (MgCO3·3H2O) was synthetized by low-temperature hydrothermal technique using purified MgCl2-rich brine and ammonium hydrogen carbonate solution as raw materials, the orthogonal experimental as method. The morphology could be tuned by changing the operating parameters. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize the structures and morphologies of the products. The results show that the optimum conditions are as follows : reaction temperature is 40-50°C, n (Mg2+):n (HCO3-)=1:2.2, pH value is 8.8-9.0, stirring speed is 130 r/min, aging time is 3h, reaction time is 70 min. Magnesium carbonate tri-hydrate synthetized is one-dimensional acicular with good settling performance. Average aspect ratio could up to 29.60.

Process Study on Green Treatment of Waste Anolyte

2014 ◽  
Vol 1015 ◽  
pp. 350-354
Author(s):  
Li Na Chen ◽  
Wan Yi Liu ◽  
Qi Lin Hu
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Chemical Precipitation ◽  
Environmental Benefits ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Waste Solution ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen

Contraposing the waste anolyte of industry, the paper proposed a new chemical precipitation method to recover Mn (II) ions and Mg (II) ions from the waste solution using ammonium hydrogen carbonate and ammonium dihydrogen phosphate as precipitants, respectively. The technological conditions of dealing procedure such as the molar ratio of reactants, pH value, reaction temperature and time, aging time were investigated. The results shown that the removal rate of Mn (II) ions and Mg (II) ions reached to 96 % and 98 %, and the yields of MnCO3 and NH4MgPO4·6H2O reached to 91 % and 94 %, respectively. The residual solution was recycled to realize the treatment greenly, which could meet the needs of production and increase environmental benefits.

Synthesis of (Y,Gd)2O3:Eu nanopowder by a novel co-precipitation processing

2004 ◽  
Vol 19 (12) ◽  
pp. 3586-3591 ◽  
Author(s):  
Jiyang Chen ◽  
Ying Shi ◽  
Jianlin Shi
Keyword(s):  
Electron Microscopy ◽  
Ammonium Hydroxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen ◽  
Intense Luminescence ◽  
Co Precipitation

Nano-sized (Y,Gd)2O3:Eu powders were synthesized by a novel co-precipitation processing in which a mixture of ammonium hydroxide and ammonium hydrogen carbonate was adopted as a complex precipitant. Evolution behaviors of precursors during calcinations were studied by means of thermogravimetry-differential scanning calorimetry-mass spectrum, Fourier transform infrared, x-ray diffraction, scanning electron microscopy, and transmission electron microscopy in detail. Nano-sized (Y,Gd)2O3:Eu powder as prepared possessed a primary grain size of about 30 nm and specific surface area of 38 m2/g after being calcined at 850 °C for 2 h, showing much finer grains and less agglomeration. The as prepared nanopowder shows intense luminescence at 611nm under x-ray or ultraviolet excitation. Transparent (Y,Gd)2O3:Eu ceramics can also be fabricated using this high sinterable nanopowder.

Preparation of Forsterite by Solid State Synthesis Process and its Dielectric Properties

2012 ◽  
Vol 534 ◽  
pp. 110-113 ◽  
Author(s):  
Fei Shi ◽  
Peng Cheng Du ◽  
Jing Xiao Liu ◽  
Ji Wei Wu ◽  
Chun Yuan Luo
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Single Phase ◽  
Raw Materials ◽  
Magnesium Carbonate ◽  
Solid State Synthesis ◽  
Molar Ratio ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray

Using basic magnesium carbonate (Mg(OH)2•4MgCO3•6H2O) and SiO2 as raw materials, forsterite (Mg2SiO4) was prepared by solid state synthesis process. The optimal process for synthesizing Mg2SiO4 was obtained by adjusting Mg/Si molar ratio and sintering temperature. The crystal phase of the obtained Mg2SiO4 powder was determined by X-ray diffraction (XRD). The results indicate that the single-phase Mg2SiO4 powder can be obtained when the mixtures with Mg/Si molar ratio of 2.05～2.01 were sintered at 1350°C for 3h in the air. The as-prepared Mg2SiO4 ceramic samples which were sintered at 1300～1360°C showed better dielectric properties with εr=7.4 and tanδ =7.5×10-4.

scholarly journals An application of classical and instrumental methods of analysis in quality control of beer

2015 ◽  
Vol 60 (4) ◽  
pp. 477-503
Author(s):  
Milos Rajkovic ◽  
Ivana Sredovic-Ignjatovic ◽  
Ljubisa Ignjatovic ◽  
Viktor Nedovic ◽  
Slobodan Prijic
Keyword(s):  
Ph Value ◽  
Raw Materials ◽  
Chloride Ions ◽  
Chromatography Method ◽  
Ph Values ◽  
Phosphate Ions ◽  
Hydrogen Carbonate ◽  
City Water ◽  
Safety Of Drinking Water ◽  
Instrumental Methods

In order to control the quality of beer and raw materials for production of beer in Belgrade Beer Industry (BIP), water is analyzed (city, technological and demineralized water). Measurements of pH values indicated the increased pH values in the sample of tehnological water, which had no impact on wort hopping, since the tested samples of wort, young beer and final product had a pH value within the expected range. After processing city water, a sample of tehnological water was found with increased carbonate hardness, which is caused by the increased content of sodium hydrogen carbonate. Analysing the titration alkalinity, titration acidity and buffering power, it was found that the alkalinity was decreasing which is in accordance with the determination of pH values of wort and beer samples (young beer and final product). Analyzing the content of anions and cations in the examined water samples, it has been shown that the concentration of these examinated anions (Cl-, NO3 -, SO4 2- and PO4 3-) and cations (NH4 +, Na+, K+, Ca2+, Mg2+) are within the limits prescribed by the Regulations on hygienic safety of drinking water, and thus by the Regulations of quality and other requirements for beer. The contents of anions in wort and beer samples (young beer and final product) were determined by ion chromatography method. The contents of sulphate and nitrate ions were within the recommended limits. The concentration of chloride ions was above 150 mg/dm3, which may have an impact on the sensory properties of beer, while changes in the content of phosphate ions were insignificant.

Study on the Salt Precipitation Law of La Guocuo Salt Lake Brine with Pretreatment at 5°C

2014 ◽  
Vol 881-883 ◽  
pp. 683-688
Author(s):  
Yu Hu Cui ◽  
Jian Jun Yuan
Keyword(s):  
Sodium Chloride ◽  
Sodium Sulfate ◽  
Magnesium Chloride ◽  
Salt Lake ◽  
Magnesium Carbonate ◽  
Salt Precipitation ◽  
Chloride Hexahydrate ◽  
Evaporation Concentration ◽  
Salt Lake Brine ◽  
Borate Salts

The brine from La Guocuo was pretreated with adding magnesium chloride hexahydrate, and it evaporated at 5°C. The salt precipitation law is obtained by evaporation experiment of this pretreated brine. In the evaporation concentration process, the salts precipitate phases are successively: magnesium carbonate, sodium sulfate, borate salts, sodium chloride and glaserite.

Preparation of Co4W6O21(OH)2·4H2O via Microwave Hydrothermal Method and its Reaction Process

2014 ◽  
Vol 809-810 ◽  
pp. 288-293 ◽  
Author(s):  
Xiu Juan He ◽  
Li Yun Cao ◽  
Xin Gang Kong ◽  
Jian Feng Huang ◽  
Jian Peng Wu
Keyword(s):  
Absorption Spectrum ◽  
Ph Value ◽  
Raw Materials ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Rhombic Dodecahedron ◽  
Cubic Crystal ◽  
Microwave Hydrothermal ◽  
Cobalt Tungstate ◽  
Gap Width

A new kind cobalt tungstate in Co4W6O21(OH)2·4H2O was smoothly synthesized by microwave hydrothermal process lasting for 80min at 190°C, in which Co (NO3)2·6H2O and Na2WO4·2H2O of analytical grade were selected as raw materials as well as the pH values adjusted from 3 to 5.5. Furthermore, the phase structure and the morphology of target products were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Additionally, the absorption spectrum of these samples was detected by UV-Vis spectrophotometer. The results showed that the cobalt tungstate in Co4W6O21 (OH)2·4H2O structure belonged to the cubic crystal system with the lattice constant of 12.858Å and its micro geometric configuration tended to be rhombic dodecahedron. On the condition of pH value at four is best for the propagation of crystals. Moreover, in the absorption spectrum it is indicated that the band gap width of this materials equaled to 3.18eV at pH=4 while 3.81eV at pH=5.

scholarly journals Effect of pH Value on Synthesis and Properties of Zinc Cobalt Ferrite Nano Powders Prepared via Co-Precipitation Method

2020 ◽  
Author(s):  
Behrooz Shahbahrami ◽  
Sayed Mahmood Rabiee ◽  
Reza Shidpoor
Keyword(s):  
Tensile Strain ◽  
Cobalt Ferrite ◽  
Ph Value ◽  
Raw Materials ◽  
Compressive Strain ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Effect Of Ph ◽  
Co Precipitation ◽  
Crystallite Diameter

Abstract The effect of pH value on the synthesis of zinc cobalt ferrite nano powder via co-precipitation method was investigated. Zinc cobalt ferrite (Co0.6Zn0.4Fe2O4) precipitated using a solution of nitrate raw materials under different pHs (pH=8, 10, 11, 12 and 14) and calcined at 750 °C for 2 hours. The obtained nano-powders were characterized by X-ray diffraction (XRD), Williamson-Hall relations and Extrapolate functions, field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) measurements. The amount of pH had a significant effect on the structural and magnetic properties of the synthesized powders. At pHs 8 and 10, a tensile strain and above that a compressive strain was created in the system. By changing the tensile strain to compression the crystallite diameter increased, so that the crystallite diameter increased from 19.3 nm at pH 8 to 47.8 nm for pH =11. The HC of the all samples was in the range of 140-150 Oe. The saturation magnetization, anisotropy and Bohr magneton constants were 100.38 emu/gr, 15357.70 erg/Oe and 4.27, respectively for the synthesized sample at pH=11, which were higher than the other samples. These changes are due to the effect that pH has on the parameters of the crystallite diameter, particle size and also on the cation distribution of the ions in tetrahedral/octahedral spaces.

Application of Polysilicate Ferric Flocculant in Treatment of Tanning Wastewater

2010 ◽  
Vol 113-116 ◽  
pp. 96-99 ◽  
Author(s):  
Zhi Hui Sui ◽  
Xin Zhao ◽  
Xu Mei Song
Keyword(s):  
Ph Value ◽  
Raw Materials ◽  
Removal Rate ◽  
Amorphous Polymer ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Polymer Flocculant ◽  
Better Than

A new type of inorganic polymer flocculant polysilicate ferric(PSF) was prepared by using pyrite slag as raw materials and used as flocculant in the treatment of tanning wastewater. The infrared spectrometry and X-ray diffraction had been adopted to characterize the product structure. The infrared spectrometry research indicates that Fe-O, Si-O-Fe and other groups exist in the PSF, which implies that chemical bonding reaction takes place between Fe and silicon in the PSF. X-ray diffraction analysis indicates that PSF is the amorphous polymer created upon mutual reaction between Fe3+ and PSi. The application experiment results show that the removal rate of S2-, SS, CODCr, Cr3+, and colority is 92.7%, 90.5%, 82.5％, 80.2% and 90.1% respectively in the condition where temperature is normal, pH value is 7.5 and dosage of the coagulant is 80mg/L. The flocculation effects of PSF in the treatment of tanning wastewater are much better than those of PAC and PFS.

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