Progress of High Purity Magnesium Oxide Preparation

2014 ◽  
Vol 525 ◽  
pp. 62-65 ◽  
Author(s):  
Bi Jun Luo ◽  
Dan Wu ◽  
Li Cong Wang ◽  
Xi Ping Huang

The research status of high purity magnesium oxide preparation is introduced in this paper. First, process for preparing high purity MgO is summarized, the global and domestic production status of high purity magnesia is also described. Finally, the problems and disadvantages of current MgO preparation methods are concluded, also development direction of preparation method basing on brine utilization in the production of MgO is put forward.

Author(s):  
Toshihiko Takita ◽  
Tomonori Naguro ◽  
Toshio Kameie ◽  
Akihiro Iino ◽  
Kichizo Yamamoto

Recently with the increase in advanced age population, the osteoporosis becomes the object of public attention in the field of orthopedics. The surface topography of the bone by scanning electron microscopy (SEM) is one of the most useful means to study the bone metabolism, that is considered to make clear the mechanism of the osteoporosis. Until today many specimen preparation methods for SEM have been reported. They are roughly classified into two; the anorganic preparation and the simple preparation. The former is suitable for observing mineralization, but has the demerit that the real surface of the bone can not be observed and, moreover, the samples prepared by this method are extremely fragile especially in the case of osteoporosis. On the other hand, the latter has the merit that the real information of the bone surface can be obtained, though it is difficult to recognize the functional situation of the bone.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Liang Yu ◽  
Xiaoan Kang ◽  
Luona Chen ◽  
Kun Luo ◽  
Yanli Jiang ◽  
...  

The zone refining method is a physical method for effectively purifying metals. Increasing yield and reducing impurity content have always been the focus of its research. This article systematically summarizes the relevant research on the production of high-purity metals by zone refining, including mechanisms, parameter optimization, zone refining types, analysis methods, limitations, and future development directions, and it provides relevant theoretical foundations for the production of high-purity metals as well.


2013 ◽  
Vol 798-799 ◽  
pp. 1166-1169 ◽  
Author(s):  
Kun Huang ◽  
Bing Xin Du

The accelerated process of urbanization and industrialization leads to the increase of sewage sludge production. The reuse of excess sludge which meets the idea of sustainable development is aimed to develop it into resources. Preparation of sludge-based adsorbents with various functions provides a new way for sludge utilization as a resource in China. The preparation method of sludge-based adsorbents and its application in wastewater and waste gas treatment are introduced. Suggestions about the research direction of sludge-based adsorbents in the future are point out.


2014 ◽  
Vol 5 ◽  
pp. 658-666 ◽  
Author(s):  
Difa Xu ◽  
Shaowen Cao ◽  
Jinfeng Zhang ◽  
Bei Cheng ◽  
Jiaguo Yu

Silver chromate (Ag2CrO4) photocatalysts are prepared by microemulsion, precipitation, and hydrothermal methods, in order to investigate the effect of preparation methods on the structure and the visible-light photocatalytic activity. It is found that the photocatalytic activity of the prepared Ag2CrO4was highly dependent on the preparation methods. The sample prepared by microemulsion method exhibits the highest photocatalytic efficiency on the degradation of methylene blue (MB) under visible-light irradiation. The enhanced photocatalytic activity could be ascribed to the smaller particle size, higher surface area, relatively stronger light absorption, and blue-shift absorption edge, which result in the adsorption of more MB molecules, a shorter diffusion process of more photogenerated excitons, and a stronger oxidation ability of the photogenerated holes. Considering the universalities of microemulsion, precipitation, and hydrothermal methods, this work may also provide a prototype for the comparative study of semiconductor based photocatalysis for water purification and environmental remediation.


2014 ◽  
Vol 955-959 ◽  
pp. 3665-3670
Author(s):  
Li Ying Zhou ◽  
Wen Ge Zuo ◽  
Zhi Mei Li ◽  
Chang Shou Luo

In order to profile the research status of soil pollution, and grasp the development direction of the disciplines, based on the soil pollution related research papers included in EI compendex, by the controlled terms of EI thesaurus, we used words co-occurrence clustering to identify the current six subfields of international soil pollution studies, investigated the development and change of them with time case, and pointed out the journals that different subfields should focus on by analyzing the relevant periodicals distribution, to provide reference for the research institutes, researchers, and policy makers in soil pollution related field.


1994 ◽  
Vol 28 (2) ◽  
pp. 182-185 ◽  
Author(s):  
Milap C. Nahata ◽  
Richard S. Morosco ◽  
Thomas F. Hipple

OBJECTIVE: To determine the effect of four preparation methods and extended storage on rifampin concentration in extemporaneously prepared suspensions. DESIGN: Four preparation methods were used: mixing intravenous (iv) rifampin in syrup (A); manufacturer's recommended technique of mixing capsule (Rifadin) contents in syrup (B); triturating capsule contents in syrup into a paste and adding remaining syrup while mixing (C); and triturating capsule contents in syrup into a paste, adding syrup, retriturating the slurry, and adding remaining syrup while mixing (D). Samples were drawn from each of five bottles of each of the four preparations stored at 4 °C, immediately after mixing (day 0), and on days 7, 14, 28, 42, 56, 70, and 91 days during storage. Rifampin wes measured by a stability-indicating HPLC method. RESULTS: The measured mean concentrations of rifampin were nearly 100 percent of the initial concentration in the suspension prepared from iv rifampin solution (method A) during the first 56 days of storage. In contrast, the measured concentrations were substantially lower than expected in the suspensions prepared by methods B, C, and D. The mean rifampin concentrations in suspensions prepared by methods B, C, and D were only 14.5, 38.6, and 68 percent, respectively, of the initial concentration achieved by method A. The rifampin concentrations increased with storage time in suspensions prepared by methods B, C, and D. The mean rifampin concentration was lower than 90 percent during the first 14 days with methods B and C, and the first 7 days with method D. The highest mean concentrations were observed on day 42 with method B, and on day 28 with methods C and D. All methods yielded 90% of the labeled potency (10 mg/mL) on day 56. CONCLUSIONS: Our results showed that preparation method can influence the dispersion, and thus the measured concentration, of rifampin in aliquots of suspensions prepared from capsules and stored in plastic bottles. Suspensions prepared from capsules led to lower-than-expected rifampin concentrations; those prepared from iv rifampin did not. Rifampin was stable in each type of suspension for 56 days at 4 °C.


2021 ◽  
pp. 15-19
Author(s):  
V. Z. Kozin ◽  
A. S. Komlev ◽  
E. V. Stupakova

Sample preparation methods are usually developed following respective recommendations of the applicable sampling standards. Modern sampling theories allow designing and optimizing these methods. Random errors in sample preparation are calculated based on a theoretical description of the piecewise heterogeneity of the sample obtained using the formulas for the fundamental sampling error. The concept of a piecewise coefficient of variation is introduced and used to develop a formula for the relative error of the sample preparation method. Using a method compiled in accordance with GOST 14180-80 for copper ore as an example, the relative error is established for the preparation of an ore sample with the copper mass fraction of 1.3 %. It is shown that a change in the final preparation size from 0.1 to 0.08 mm affects the error only insignificantly, and sample size changes by stages allow designing a preparation method with the smallest error. It is advisable to analyze the method compiled and change its parameters on the basis of a structural assessment of the influence of individual preparation stages on the error. Sample preparation examples for copper and gold-bearing ore are used to demonstrate the analysis procedure and the parameter changes. Traditionally, the minimum sample masses are established for all stages based on the volumetric heterogeneity of the sample being tested and the size of the sample material. The minimum masses should be found depending on the grain size of the valuable mineral in the ore, the permissible relative error for the size reduction, and the material size for the sample reduced by a factor of 1.5 for nonferrous metal ores.


2013 ◽  
Vol 671-674 ◽  
pp. 333-336
Author(s):  
Yang Liu ◽  
Xian De Zhu ◽  
Chen Ye Wan

Three numerical sample preparation methods, namely, radius expand method, hierarchical compaction method and gravity descent method, were studied using discrete element method (DEM) to simulate the actual sample. The processes of these three methods were described in details and the differences of these three methods were discussed. The impacts of mechanical parameters in DEM model on the numerical results were analyzed.


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