Production Features of Magnesium-Neodymium Master Alloy Synthesis

Savchenkov, S. А.; Bazhin, V. Yu.; Brichkin, V. N.; Kosov, Ya. I.; Уголков, В. Л.

doi:10.1007/s11015-019-00835-6

Cited by 8 publications

(7 citation statements)

References 10 publications

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“…Also, a film of sodium titanate can form on the surface of boehmite, which is known [52] to reduce the rate of dissolution of aluminum hydroxides significantly. For water-leached dust, the highest determination coefficient is observed, when using Equation (2) (Figure 7c), which implies that the process is limited by diffusion through the layer of the product or unreacted matter. Using the obtained values of the apparent rate constant (ki) in Figure 7b,d and the Arrhenius equation (Equation 4), we determined the values of the apparent activation energy for leaching ESPD and ESPDW ( Figure 6) to be 24.98 kJ/mol and 33.19 kJ/mol, respectively.…”

Section: Kinetics Of Esp Dust Leaching By Alkaline Aluminate Liquormentioning

confidence: 98%

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Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust

et al. 2020

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One of the potential sources of rare-earth elements (REE) is the industrial waste known as red mud (bauxite residue), in which the majority of REE from the initial bauxite are concentrated via the Bayer process. Therefore, the studies of the subject, both in Russia and outside, focus almost exclusively on red mud processing. This article looks into the possibility of REE concentration into red mud by leaching an intermediate product of the bauxite sintering process at Russian alumina refineries, namely electrostatic precipitator (ESP) dust. The experimental works were performed by X-ray diffraction (XRD)and electron probe microanalysis (EPMA) of the sinter and sinter dust. The determination of major and rare-earth elements in the sinter from the rotary kilns and in the ESP dust before and after leaching was carried out by X-ray fluorescence (XRF) and plasma mass spectrometry (ICP-MS). The study showed that it is possible to obtain red mud that contains three times more REE than traditional waste red mud after two-stage leaching ESP dust in the water at 95 °C followed by leaching in an alkaline-aluminate liquor at 240 °C. The shrinking core model was used to study the kinetics of leaching of the original ESP dust and water-treated dust in alkaline-aluminate liquor. The study showed the change in the limiting stage of the alkaline leaching process after water treatment, with the activation energy growing from 24.98 to 33.19 kJ/mol.

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Section: Kinetics Of Esp Dust Leaching By Alkaline Aluminate Liquormentioning

confidence: 98%

“…The volumes of production/consumption of rare and rare-earth metals, which are critical for modern industries, are steadily increasing [1][2][3][4]. In this group of metals-scandium, yttrium, lanthanum, and lanthanides-scandium is the most scarce and commercially attractive one.…”

Section: Introductionmentioning

confidence: 99%

Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust

et al. 2020

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“…where Bo A is the Bodenstein number for the case of axial mixing, and Bo L is the Bodenstein number for longitudinal mixing. When Bo L Bo R , Equation (30) takes the form of dependence (31). To reduce the time required for an experiment to determine the shape of the curve of the distribution function and verify the adequacy of the investigated reactor with the complex model, it is necessary to obtain the values of τ, the average residence time, using the time-similarity simplex from (28).…”

Section: Dispersion Modelmentioning

confidence: 99%

“…To determine the mathematical model parameters for a continuous reactor, it is first necessary to consider the RTD of the material in the apparatus, which will ultimately improve the economic efficiency of the process under consideration. Information about RTD in the apparatus enables evaluation of the efficiency of the apparatus itself, which determines the proportion of the apparatus volume occupied by particles within a given time interval [28][29][30].…”

Section: Introductionmentioning

confidence: 99%

An Interval-Simplex Approach to Determine Technological Parameters from Experimental Data

Белоглазов

Krylov

2022

Mathematics

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Statistical equations are widely used to describe the laws of various chemical technological processes. The values of constants and parameters included in these equations are determined by various methods. Methods that can determine the values of equation parameters using a limited amount of experimental data are of particular practical interest. In this manuscript, we propose a method to obtain simplex-interval equations. The proposed approach can be effectively used to control the values of technological process parameters. In this paper, we consider examples of chemical kinetics equation transformations and heterogeneous processes of solid particle dissolution. In addition, we describes mathematical model transformations, including equations for functions of the residence time distribution (RTD) of apparatus particles, the distribution of particles by size, etc. Finally, we apply the proposed approach to an example involving modeling of the calcination of coke in a tubular rotary kiln.

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“…The main problems in the arc deposition of magnesium alloys are associated with a number of factors [8,9]:…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Structure and Properties of Magnesium Alloys during Plasma Additive Deposition

et al. 2021

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This paper deals with the additive manufacture of magnesium alloy products of the magnesiumaluminum-manganese-zinc system by plasma surfacing with a reverse polarity current. Special attention was paid to the following points: studying the influence of evaporation of alloying elements during plasma additive surfacing on the material quality; studying the influence of surfacing modes (continuous filling and layer-by-layer filling with cooling at different thermal cycles) on the formation of structure and properties of the synthesized material; specifying the influence of the heat treatment on the structure and properties of the deposited metal. A correct selection of plasma surfacing parameters eliminates porosity and cracks in deposited layers. It is established that plasma surfacing provides a relative structural and phase stability of the previous layers under the influence of subsequent thermal cycles during the workpiece manufacture. In general, the dispersion of the structure of the deposited MA5 alloy is significantly higher than that of the cast and heat-treated metal structures produced by conventional technologies. Plasma surfacing with a reverse polarity current provides a deposited metal with high mechanical properties, i.e. a unique 5-9-fold increase in ductility compared to the cast material with an increase in ultimate strength by 7-10%, both with and without heat treatment.

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Production Features of Magnesium-Neodymium Master Alloy Synthesis

Cited by 8 publications

References 10 publications

Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust

Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust

An Interval-Simplex Approach to Determine Technological Parameters from Experimental Data

Characteristics of Structure and Properties of Magnesium Alloys during Plasma Additive Deposition

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