scholarly journals Synthesis of Mg–Zn–Nd Master Alloy in Metallothermic Reduction of Neodymium from Fluoride–Chloride Melt

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 985 ◽  
Author(s):  
Ilia Beloglazov ◽  
Sergey Savchenkov ◽  
Vladimir Bazhin ◽  
Rudolf Kawalla

In the presented article, a differential thermal analysis was carried out and the temperatures of thermal effects were established that arise during the reduction of neodymium from a technological salt mixture KCl–NaCl–CaCl2–NdF3 with a magnesium–zinc alloy. The results of experimental studies on the reduction of neodymium from a fluoride–chloride melt in a shaft electric furnace at temperatures of 550, 600, 650, 700 °C are presented. In order to increase the degree of extraction of neodymium into the Mg–Zn–Nd master alloy, the study of the influence of technological parameters on the degree of extraction of neodymium was carried out. It was experimentally proven that when zinc is added to a reducing agent (magnesium), the degree of extraction of neodymium into the master alloy is 99.5–99.7%. The structure of the obtained master alloy samples, characterized by a uniform distribution of ternary intermetallic compounds (Mg3,4NdZn7) in the volume of a double magnesium–zinc eutectic, was studied by optical and electron microscopy.

Author(s):  
O. Yu. Kichigina

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.


2020 ◽  
Vol 60 (1) ◽  
pp. 261-268
Author(s):  
O.M. Trokhaniak ◽  
R.B. Hevko ◽  
O.L. Lyashuk ◽  
T.A. Dovbush ◽  
B.V. Pohrishchuk ◽  
...  

The article presents the results of theoretical and experimental studies of the process of moving bulk material in the inactive zone between hinged screw sections of a flexible screw conveyor. The influence of the gap between the edges of adjacent screw sections and the magnitude of their circular displacement on the process of continuous transportation of bulk material is presented. The results of theoretical and experimental studies are compared. This will allow choosing the optimal design, kinematic and technological parameters of the developed sectional screw working body when transporting bulk agricultural materials along curved paths, both in horizontal and inclined directions, as well as along curved paths.


2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.


Author(s):  
E. I. Marukovich ◽  
E. B. Demchenko

The analysis of the performed researches has shown that the offered calculation technique is an effective means of management of formation process in casting. The found dependences and experimental data allow to calculate the specific value of the exactм heat flux in a given range of technological parameters obtained during a series of successful experiments for a particular casting method.Having the results of studies of the temperature regime of the mold during casting of a certain size and profile, it is possible to calculate the thermal state of the mold for the same casting process, but for the production of castings of any other size and profile.Having a certain amount of information on the temperature regime of the mold at different casting methods, you can use the solutions obtained to become the owner of a database containing the necessary information for solving the problems of solidification of the casting. In the subsequent design of equipment and equipment there is no need for additional experimental studies and analysis of the results.


Author(s):  
G. Golub ◽  
◽  
A. Dvornyk

The goal of the work. Investigate the influence of the relative position of the depth of processing with a chisel, the speed of movement of the unit and the distance between the cutting side discs on the lumpiness of the processed strip. Methods of research: analytical - quantitative determination of the quality of strip tillage; laboratory-field - for research, an experimental installation was completed with an MTZ-892 tractor and a section of the unit for strip tillage; statistical with generally accepted agronomic and economic methods. Results. Experimental studies of changes in the design and technological parameters of the unit for strip processing with the determination of lumpiness have been carried out. To study the main parameters, the depth of processing of the subsoiler (chisel) is taken from 13 to 27 cm, the distance between the cutting side discs is from 10 to 30 cm, the speed of the MTA is from 4 to 11 km/h. Unchanged parameters during the study: the distance from the axis of the front disc to the chisel is 50 cm, the distance from the chisel to the axis of the cutting side discs is 50 cm, the immersion depth of the cutting side discs is 10 cm. Experimental background is winter wheat stubble. Soil cultivation for winter wheat - deep (18 cm) disking, before that plowing to a depth of 25 cm. According to the research results, graphs of the dependence of lumpiness on the relative position of the chisel, cutting side discs and changes in the speed of the MTA were built. As the speed and distance between the side cutting discs increase, the lumpiness value decreases. Conclusions. Based on the results of the studies, the dependences of lumpiness on the relative position of the chisel and cutting side disks were obtained when the speed of the MTA was changed. It was determined that with an increase in the processing depth, the distance between the cutting side discs of 20 cm and the MTA movement speed of 7.5 km / h, a uniform increase in lumpiness is observed. The distance between the side cutting discs of 10 cm is not suitable for work.


2018 ◽  
Vol 37 (9-10) ◽  
pp. 889-898 ◽  
Author(s):  
Mehmet Bugdayci ◽  
Murat Alkan ◽  
Ahmet Turan ◽  
Onuralp Yücel

AbstractMill scale (MS) has a potential to use as an iron source because of its high iron content. MS mainly consists of a mixture of iron oxides, metallic iron and other base metal oxides. MS is formed on the surfaces of steel ingots during continuous casting as a waste material. In this study, the use of MS as an iron source for the production of carbon-free iron containing alloys (unalloyed iron, Fe-Ni, Fe-Cr-Ni, Fe-Cr-Ni-Mo) via a metallothermic reduction process was investigated. Thermodynamic calculations and the experimental studies were performed on the basis of 100 g of MS. The effects of different stoichiometric amounts of MS and aluminum (Al) powders (as reductant) were investigated for the production of unalloyed Fe. While, different amount of metal oxide ratios and their effects on metal recoveries, compositions and microstructure of final alloys were studied during Fe-based alloys production. The highest iron recovery during unalloyed Fe production was obtained as 95.14 % by using 100 g of MS and 100 % stoichiometric Al (28.6 g) containing mixture. In Fe-based alloys production series, the highest metal recovery values were reached up to 95.0 % for Fe, 95.1 % for Ni, 68.3 % for Cr and 77.2 % for Mo, respectively.


2018 ◽  
Vol 178 ◽  
pp. 01015 ◽  
Author(s):  
Uwe Teicher ◽  
Richard Schulze ◽  
Alexander Brosius ◽  
Andreas Nestler

The extension of technical capabilities of machine centres for complete machining of components can improve their performance. In the field of sheet metal machining, the objective beside the classic milling operation was a generation of functional surfaces by face brushing. The experimental studies have probed the influence of tools and technological parameters on the surface quality. In addition to an analysis of the relevant roughness parameters the formation of the surface topography was analysed by several measurement methods. By the application of force measurement, the results of the surface quality can be interpreted additionally. It could be shown that the feed rate in contrast to the cutting speed has the main influence on the surface roughness. A peculiarity is given by the parameter-based width of cut that should be known for reliable process control. The acquired data can be applied in the form of process characteristic fields for further processing with simulation and modelling methods.


2019 ◽  
Vol 135 ◽  
pp. 01049
Author(s):  
Rashid Sharapov

The article focuses on the need to improve the ecology in modern cities based on the development of new cleaning equipment. It is proposed to use a granular filter as a dust cleaning unit in sweeping machines. The advantages of granular filters over other types of filtering apparatus are given. The basic schemes of working equipment of sweepers are considered. To describe the processes during air purification in the proposed granular filter, mathematical expressions are proposed to determine the hydraulic resistance of the proposed filter. When developing analytical expressions, the structural and technological features of the proposed filter were taken into account. The results of calculating the hydraulic resistance of the proposed granular filter depending on its main structural and technological parameters are obtained. To confirm the obtained analytical expressions, experimental studies were carried out. The clinker of the Belgorod cement plant of a fraction of -10 + 5 mm was selected as the filtering material. During the experiment, cement was used as dust with a specific surface of various dispersion, determined by the parameter δ50. In addition, filtering speed and filtering time are accepted as variable parameters.


Author(s):  
A. A. Kataev ◽  
O. Yu. Tkacheva ◽  
N. G. Molchanova ◽  
Yu. P. Zaikov

The study covers the process of obtaining the Al–B master alloy by the KBF4and B2O3aluminothermic reduction using KF–AlF3and KF–NaF–AlF3fluoride fluxes at 983 and 1123 К, respectively, and KCl–NaCl–KF chloride-fluoride fluxes at Т= 1173÷1223 К. All experiments were carried out under the same conditions: molten mixture stirring rate was 400 rpm, synthesis duration was 30min. The maximum amount of boron (1,5 %) in the Al–B alloy was obtained when using KBF4(3 % per B) as a boron-containing raw material in the KF–AlF3medium with a molar (cryolite) ratio (CR) of KF/AlF3equal to 1,3, atТ= 983 К, while boron recovery ratio did not exceed 75 %. Comparable results were obtained in experiments with KF–NaF–AlF3f lux (CR = 1,5) at Т= 1123 К. However, with the increased concentration of fed boron its recovery ratio decreased substantially. It is connected with the higher decomposition temperature of not only KBF4, but also less thermally stable NaBF4 formed as a result of exchange reaction in the melt. Therefore it is not recommended to use sodium salts as a f lux component. The Al–B master alloys obtained by KBF4reduction in fluoride fluxes were solid solutions of B in Al containing the AlB2intermetallic compound. The lowest amount of boron in aluminum with the minimum degree of extraction was obtained in experiments with the B2O3in molten KF–AlF3with CR = 1,5. Nevertheless, the results of scanning electron microscopy indicate a uniform distribution of B over the Al matrix and the absence of intermetallic compounds, while a large amount of Al2O3was found, which is the product of B2O3reactions with both liquid Al and KF–AlF3flux.


2016 ◽  
Vol 11 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Лукманов ◽  
Ruslan Lukmanov ◽  
Мустафин ◽  
Anas Mustafin ◽  
Зиганшин ◽  
...  

A device of disconnection a milking machine at the end of milking was created to improve the efficiency of machine milking cows. On the basis of theoretical and experimental studies we proved constructive and technological parameters and operation modes of the air engine.


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