Research of kinetics of zinc leaching with sulfuric acid from smithsonite

The study investigates the kinetics of zinc leaching from smithsonite with sulfuric acid in order to expand the zinc production feedstocks. The recovery rate of zinc from smithsonite into water-soluble zinc sulfate was found at different leaching time and temperature. Sulfuric acid concentration, its consumption and smithsonite particles size selected in this work for leaching of zinc from this mineral using the indicated solution allowed to determine the magnitude of “apparent” activation energy of the smithsonite reaction with the indicated acid, equal to 2,633 kJ / mol. The calculated value of E, shows that the process investigated is accompanied by diffusion phenomena

Investigation of the kinetics of sulphuric acid leaching of zinc from calamine

This article aims at the research of kinetics of the sulphuric acid leaching of zinc from calamine (hemimorphite) of Shaimerden deposits. The ratio of zinc extraction from calamine to water-soluble zinc sulphate was determined at various leaching durations and its temperatures. The concentration of the sulfuric acid solution, the flow rate of this solution and the size of the calamine particles, selected in the course of this work for leaching zinc from this mineral with the specified solution, made it possible to establish the value of the “apparent” activation energy of the reaction of calamine with sulfuric acid, amounting to 3,075 kJ / mol

Improving the assay-gravimetric method for determining the content of noble metals

The study considers the current state and problems of analytical control as the most important component of all stages of technology and production of noble metals. Based on the analysis carried out, a universal method for measuring the mass fraction of gold and silver in ores, products of their enrichment and metallurgical processing by the assay-gravimetric method was improved, and the optimal parameters for determining gold and silver were determined

The problem of correctness and reliability of the study in trilingual education

This article deals with the problem of correctness and reliability of experimental research methods and simulations of the basic research methods of decision the problem in a pedagogical experiment. Modeling of the educational process is used of the context with classical methods of research and modern innovative methods of self-education, co-education, cooperation and self-organization of the synergetic approach in pedagogy. In particular, the analysis and synthesis of classical scientific and methodical works on the subject of research are combined with the methods of modeling the educational process and mathematical modeling as an argumentative basis of the reliability of the results.Este artículo aborda el problema de corrección y fiabilidad de métodos de investigación experimental y las simulaciones de métodos básicos de investigación del problema en un experimento pedagógico. La modelización del proceso educativo se utiliza en el contexto de los métodos clásicos de investigación y los métodos innovadores modernos de autoeducación, coeducación, cooperación y autoorganización del enfoque sinérgico en pedagogía. En particular, se combinan el análisis y síntesis de trabajos científicos y metodológicos clásicos sobre el tema de la investigación con métodos de modelado del proceso educativo y matemático como base argumentativa de la fiabilidad de los resultados

The investigation of the slippage effect, transformation of the structure and properties of the Zr–1%Nb alloy during high-pressure torsion deformation

High-pressure torsion deformation (HPT) is an effective method for transforming the structure of metallic materials, forming a nanostructural state in them, and significantly improving their strength. However, deformation achieved during HPT can be much less than expected due to the slippage. The study of the slippage effect during HPT of various materials is a topical issue. Previously, the authors proposed a simple and illustrative method for assessing slippage and the actual degree of torsion deformation achieved during HPT. Zr–1%Nb alloys, on which many studies of the HPT effect previously have been carried out, are good material for studying the slippage effect during HPT. Therefore, it is possible to compare obtained data with the results of other authors. The paper investigates the HPT impact on the structure and properties of the Zr–1%Nb alloy and demonstrates the slippage effect. The initial disk, prepared for HPT, was cut into two half-disks that were jointly placed on the strikers and exposed to joint HPT for n=¼ revolutions of anvils. The authors evaluated the slippage effect from the view of halves. The study showed that even at the initial HPT stages at n=¼ revolutions, there is a significant slippage of strikers and a sample, and the torsion deformation does not accumulate as expected. The authors analyzed the influence of various HPT modes on the microhardness, structure, and phase composition of the Zr–1%Nb alloy. The study shows that, despite the slippage effect, the Zr–1%Nb alloy is strongly hardened during HPT for one revolution (n=1) and HPT with n=10; the microhardness and tensile strength increase significantly, and up to 90 % of high-pressure ω-phases is formed in the sample. The authors conclude that during HPT, the deformation is implemented not by simple torsion but by the more complex modes

Design of an Information-measuring System for Monitoring Deformation and Displacement of Rock Massif Layers Based on Fiber-optic Sensors

This paper reports a study into designing an information-measuring system that could be used in coal mines that are dangerous in terms of the explosion of coal dust and methane gas. The results of reviewing technical advancements in the field of fiber-optic system development are given. To solve the set task, prototypes of a fiber-optic sensor of a new type and a hardware-software complex were constructed. The research aims to improve the safety of workers at coal enterprises. The result of the theoretical research has established that additional losses related to a micro bending should be taken into consideration while accounting for the effect of photoelasticity. The fundamental difference between the idea reported here and existing analogs is the development of a hardware-software complex capable of working with a single-mode optical fiber of great length with a significant noise level. The data processing unit is equipped with a television matrix and can analyze changes in the pixels of a light spot. The proposed system is quasi-distributed; it controls individual points within a rock massif. The designed hardware-software system provides high noise immunity of measuring channels when the external temperature changes. The research results helped develop an information-measuring system for monitoring the deformation and displacement of rock massif layers based on fiber-optic sensors, capable of operating in an explosive environment. The system makes it possible to control several layers located in the roof of the workings, while the fiber-optic sensor may contain two or three sensitive elements that are connected to different channels. With a sharp fluctuation in pressure and an increase in the displacement parameter, the system triggers a warning signal about the danger