Kinetic Model for Denitration Reaction Process of …
The kinetics of the denitration reaction determines distribution of the nitrate group in the surface layer of NGDP, which further afects the combustion progressivity. In this paper, the kinetic model for the denitration reaction process of the cylindrical single-base gun propellant was studied by the shrinking unreacted core model (SUC model ...
Applications of microwaves in nuclear chemistry and …
The experimental results show that microwave assisted thermal denitration process has obvious advantages for the conversion of HEU compared with other …
(PDF) Use of Microwave Radiation for Denitration of Uranyl …
Use of Microwave Radiation for Denitration of Uranyl Nitrate Solution and Subsequent Sintering of Uranium Dioxide Fuel Pellets. March 2021. Russian Journal of …
The research for applying microwave denitration on the conversion …
The temperature is determined by IR-Thermometer and Photo-fibre thermometer. The size and material of denitration vessel is decided for the designated feed of HEU(90 g(I)/l, 4 mol/l HNO{sub 3} and 1.21 per batch). The working curve by microwave denitration and technical conditions are researched. The microwave …
Nickel oxide powder synthesis from aqueous solution of …
In this work, the effects on the process of the microwave denitration while using an adiabator are also investigated. Namely, the temperature distribution in the reactor and the efficiency of the denitration process to yield NiO powder are also evaluated by numerical simulation. 2. Materials and methods2.1. Microwave denitration experiment
ETHOS UP | Rotor-Based Microwave Digestion System
A number of accessories are available to help the analyst get the most out of the ETHOS UP. Milestone offers a variety of inserts in different materials (Quartz or TFM) and with various sizes and shapes, accommodating a vast array of applications. Both quartz vessels and insert options are available for the SK-15 and MAXI-44 rotors.
Development of a continuous homogeneous process for denitration …
Removal of nitric acid from high level liquid wastes (HLLW) of nuclear fuel reprocessing plants is warranted for simplifying the procedure for waste fixing. Chemical denitration aims to reduce the waste volume by destroying the acidity and subsequent concentration by adding suitable reductants. Reduction of nitric acid to gaseous …
Use of Microwave Radiation for Denitration of Uranyl …
A 500-mL quartz flask containing 250 mL of the UO 2 (NO 3) 2 solution was placed in the chamber of a Samsung MW73VR microwave oven (radiation frequency 2.45 GHz, magnetron power up to 800 W) onto a heat-protecting support made of a light fibrous ceramic composite. The flask was stoppered with a ground-in Teflon stopper with two …
Preparation of Uranium Oxides in Nitric Acid Solutions …
reagent thermal denitration: gaseous hydrogen, formal-dehyde, formic acid, urea, sugar, ethanol, etc. [13–15]. It is also appropriate to combine the process with the subsequent use of microwave radiation for preparing U oxides. In this study, we examined the possibility of preparing U oxides in solution by thermal denitration
Development of Microwave Heating Method for Co …
Step 3: Heating up of molten Pu-U nitrate salt and then thermal decomposi internally heated up in a microwave electrical field. The MH method is such a process that. tion of molten salt (~130 to ~35o·c) Step 4: Partially heating up of denitrated Pu-U nitrate solution is heated up, concentrated and then denitrated to MOX powder by.
Preparation of uranium oxides by reductive denitration of
Autoclave denitration of solid uranyl nitrate in the presence of hydrazine hydrate at 120°C under the action of microwave radiation (MWR) leads to the formation of uranium dioxide with simultaneous breakdown of excess hydrazine hydrate and nitrate ions. The reaction yields UO2 when performed in an open system in a reducing medium and …
UO2 Ceramic Grade Powders Prepared by Direct Microwave …
In this paper, the denitration process was studied by depressing the pressure inside the vessel where the solution is denitrated. Intermediate and final …
AELAB MDS-15 High-throughput Microwave Sample …
+ The quartz digestion vessel enables the digestion process to be visible. + Initiative wireless remote video monitoring system, together with quartz vessels, makes the reaction be seen clearly at a glance. Pictures and videos can be taken during the entire process; + 500 ml ultra-large digestion vessel meets the special requirements for the digestion of …
Use of Microwave Radiation for Denitration of Uranyl …
the Ar + 10 vol % H2 gas mixture, and the quartz tube was connected to a preliminarily assembled system for collecting the condensate and trapping nitrogen oxides, consisting of a refl ux condenser, a vessel for condensate collection, a buff er vessel, and two liquid seal traps with water. The UO2(NO3)2 solution was evaporated at a
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Microwave Digestion of quartz – Berghof Products
Application. Microwave Digestion of quartz. A sample preparation method of quartz for elemental analysis is introduced below. The samples are digested using speedwave XPERT in DAP-60 vessels. During the digestion, the reaction temperature is controlled via contactless in-situ temperature sensor (DIRC) to ensure efficient digestion.
Characteristics and Sinterability of MOX Powder Prepared by …
Based on the successful development of the co-conversion process, the microwave heating direct denitration facility with a 10 kg MOX/d capacity has been constructed adjacent to the reprocessing plant.
Continuous direct denitration process of plutonium
@article{osti_7777486, title = {Continuous direct denitration process of plutonium--uranium coconversion using microwave heating method}, author = {Oshima, Hirofumi and Tsuji, Nobuo}, abstractNote = {A study on the development of a continuous co-conversion process of Pu--U mixed nitrate solutions to oxide powder by using a microwave …
MARS 6 Batch Microwave Acid Digestion System
The MARS™ 6 is a microwave acid digestion system that produces clear digestate from samples for elemental analysis by ICP, ICP-MS, or AA. Rocks, plants, soil, foods, pharmaceuticals, plastics, metals, and more can be digested easily, using preloaded methods. For over 30 years, lab technicians have been using MARS systems for sample …
Microwave based oxidation process for recycling the off …
The surface area of ThO2 from bulk microwave dissolution-denitration (3.5–4.5 m2/g) was comparable to the standard and further enhanced in polyvinyl alcohol (PVA) aided denitration. View Show ...
Development of recycling processes for clean rejected
Denitration process vessel: Three types of quartz process vessels (1 l each) namely dish shaped, wide neck and narrow neck beakers were taken for MicroWave Direct Denitration experiments. 3. Jaw crusher: The feed material was passed through …
CHINA NUCLEAR SCIENCE AND TECHNOLOGY REPORT
Microwave denitration can accomplish the denitration and the conversion pro-cess from uranyl nitrate to oxide in same vessel. In microwave denitration process, the ni-trate …
UO 2 Ceramic Grade Powders Prepared by Direct Microwave Denitration …
Based on the successful development of the co-conversion process, the microwave heating direct denitration facility with a 10 kg MOX/d capacity has been constructed adjacent to the reprocessing plant.
Synthesis of Mixed Actinide Oxides Using Microwave Radiation
The method is based on the use of microwave radiation for the direct denitration of actinide nitrate solutions. The possibility of producing uranium, plutonium, …
UO2 Ceramic Grade Powders Prepared by Direct Microwave Denitration …
In this paper, the denitration process was studied by depressing the pressure inside the vessel where the solution is denitrated. Intermediate and final products were characterized. It was demonstrated that when working pressure ranges between 520 and 970 hPa during denitration, high density UO 2 pellets can be obtained without …
Kinetic Model for Denitration Reaction Process of …
As a new type of progressive energy release propellant, nitro gradiently distributed propellant (NGDP) was prepared by a denitration reaction between a denitration reagent and the propellant to remove the energy-containing functional group (–O–NO2) from the surface of the propellant. The kinetics of the denitration reaction determines distribution …
Systems for Microwave-Assisted Wet Digestion
3.3.1. Microwave-Assisted Pressurized Wet Digestion. Closed vessel MW-assisted digestion technology has been acknowledged as one of the best solutions for clean chemistry applications and has a unique advantage over conventional heating in closed vessels or even over MW open-vessel technologies.
UO{sub 2} Ceramic Grade Powders Prepared by Direct Microwave …
Journal Article: UO{sub 2} Ceramic Grade Powders Prepared by Direct Microwave Denitration at Reduced Pressures
Development of a Process for Co-Conversion of Pu-U …
For future development of the microwave heating method, a continuous direct denitration, a vitrification of high active liquid waste and a solidification of the plutonium …
7-5 Advancing Microwave Heating Denitration Technology
During reprocessing, a mixture of plutonium nitrate and uranyl nitrate is recovered from spent fuel and converted into a mixed oxide (MOX) raw powder using a microwave heating denitration method. The raw MOX powder obtained in this method has good sinterability and can produce high-quality pellets. However, raw MOX powders contain many fine ...