Calcining methods

Red mercuric oxide generally is prepared in one of two ways by the heat-induced decomposition of mercuric nitrate or by hot precipitation. Both methods require careful control of reaction conditions. In the calcination method, mercury and an equivalent of hot, concentrated nitric acid react to form... 

Q Characterization of Co/Silica Catalysts Prepared by a Novel NO Calcination Method... 

Calcination forms the hemihydrate type of calcium sulfate by the reaction CaS04 2H20 —-— CaS04 2 H20 + 2 H20. Various calcining methods have been used throughout history to... 

Bismuth vanadate can be produced by chemical precipitation, as well as by high temperature calcination methods. In the wet process, the acidic solution of bismuth nitrate, Bi(N03)3, is mixed with the alkaline solution of sodium vanadate, Na3V04. The gel formed is filtered off on a filter, pressed, washed, and converted to a crystalline form by calcination at low temperatures of 200—500°C for 1 h (37,38). 

Eu3+ Recently, Zhang et al. (2005) observed energy transfer from the host to Eu3+ in Eu3+-doped ZnO nanociystals synthesized by high temperature calcination method. The excitation spectrum consists in the strong band of the ZnO host (385 nm) and the characteristic excitation line spectrum of Eu3+ when the Eu3+ luminescence at 616 or 708 nm is monitored. Note that the latter wavelength was used to avoid the overlap with the host emis-... 

Plutonium Finishing. The separated plutonium was processed to Pu02 by conventional cation resin exchange, oxalate precipitation, and calcination methods. 

In the following sections, a brief chronology of the development of this process is presented the materials, equipment, and basic operations relating to the resin-bead loading and calcination method of producing sized curium-americium oxide microspheres at TRU are described and typical production data are presented. 

Properties of Calcined Coke. Table II shows the properties of calcined cokes A, B, C, D and F by the new and traditional methods. Regardless of the green coke type, the thermal expansion coefficient of calcined coke by the new method was lower than that of traditional calcination method. Porosity values for calcined cokes by the new method have a higher value, regardless of the coke type, than... 

Table V shows the X-ray parameters obtained from the cokes by two different calcining methods. X-ray diffractometry of interlayer spacing (doo2) and apparent crystalline size (Lc) indicated no particular difference between cokes processed under the two methods. Furthermore, no specific differences were found on these samples after graphitization, These facts show that the new calcining method would not lead to adverse effects on the development and rearrangement of coke crystallines.

From the study of the new calcining method, the following facts were revealed (16) ... 

In considering other factors that may influence water demand, many intrinsic stucco properties must be taken into account such as purity, particle size and morphology of the gypsum, calcination methods, and stucco surface properties. In addition, the water demand of stucco is dependent on its history such as aging time and conditions, aridization, and presence of surface active agents. 

The optimal calcination method for zeolite beta was established by thermogravimetric analysis using a PL-Thermal Sciences STA 1500 apparatus. Chemical compositions of the zeolites were determined by atomic absorption spectroscopy on a Varian AAIO spectrometer after dissolution of the samples in hydrofluoric acid. The structure was confirmed by x-ray diffraction on a Siemens D-5000 diffractometer and with infrared spectroscopy on a Mattson Instruments Galaxy 2000 spectrometer. Total surface area, micropore area and micropore volume of the samples were determined by argon adsorption on a Micromeritics ASAP 200M volumetric analyzer using standard techniques. Crystal diameters were determined by scanning electron microscopy. 

Du X, Zhao S, Liu Y, Li J, Chen W, Cui Y (2014) Facile synthesis of monodisperse alpha-alumina nanoparticles via an isolation-medium-assisted calcination method. Appl Phys A-Mater Sci Process 116 1963-1969... 

Using the same sol-gel precursor, one half was used for a conventional calcination and the other half for the flash-calcination" to enable a clear comparison between these two calcination methods. After X-ray profile analysis of the diffractograms, we did not observe any differences in the relative intensities, half-height widths or the peak positions. We have also performed ESCA and SEM experiments. All the results are listed in Table 3. 

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