The analysis of the engineering process of reforming dead catalysts for the extraction of platinum group metals has been carried out. Fully-dead catalyst, having passed several cycles of regeneration and entitled to utilization, has the considerable carbonaceous deposits, both on external and internal surfaces. Their content averages 5.0% of the mass of the catalyst. The research objectively consisted in selection of the sweet roasting modes, promoting the fullest removal of the dense carbonaceous deposits from the surface of the dead platinum-rhenium catalysts. The kinetics research of carbonaceous removal deposits from the surface of the catalyst was carried out in a pipe-still heater; oxygen content, duration and temperature of sweet roasting being varied. The maximum temperature during the research reached 950°C, the maximum duration of isothermal holding didn't exceed 6 hours. The extent of carbonaceous deposits removal was calculated by changing sample weight. The kinetic curves were approximated by high-order polynomials, which made it possible to obtain a diagram, illustrating the degree of organic deposits removal, depending on temperature and firing time. It is shown that in the environment enriched to 30-35 vol. % oxygen, the engineering process of catalysts for regeneration is possible to be carried out at 650 °C, with holding for 2 hours at a specified temperature. The alternative of sweet roasting is the air blowing of dead catalysts at temperature of 800 °C within an hour. Both modes guarantee the complete removal of the dense carbonaceous deposits from the surface of the dead catalyst.
Introduction. The core of technical knowledge is formed by the fundamental mathematical, physical and chemical knowledge, which is necessary for creation and improvement of devices, materials and technologies, competent implementation of production operations and use of various chemicals in the industrial sphere, taking into account their influence on the environment and the human body. Fundamental chemical training plays a significant role in the formation of chemical competency and development of the components of cross-cultural, general professional and professional competencies of future engineers. However, the analysis of educational practice demonstrates the discrepancy between the level of fundamental chemical training of graduates and the modern requirements to engineering education.Methodology and research methods. The research was carried out on the basis of multilevel methodology including dialectical principles, categories and regularities of the knowledge theory. The key ideas of the system-based, person-oriented, integrative, technological, competency-based, information-and-activity-ba- sed and environmental approaches were employed. The methods of comparative analysis and conceptual modelling were used. The assessment of the results of a pedagogical experiment was conducted by means of the method of diagnostics of reflexive abilities and the median method; the coefficient of system knowledge was calculated on the basis of the component analysis of the formed competencies.Results and scientific novelty. The concept and the structural-functional model of the fundamental chemical training of bachelors in the information-and-activity-based educational environment of blended learning have been proposed. This model provides a holistic framework for the interconnected target, content, organisational and administrative, procedural activity-based and productive evaluative blocks. Moreover, the model accumulates the achievements in the field of e-learning and involves the acquisition of the subject (chemical), methodological invariants and the variable component of the academic programme that together constitute the fundamental chemical training. An e-learning course based on videoconferencing and Web 2.0 technologies allows teachers to efficiently integrate classroom and independent work of students and to upgrade lectures and practicals. Modern pedagogical project-based technologies, gradual development of critical thinking, sustainable implementation of elements of research work into laboratory chemical practicum contribute to the positive dynamics of the quality of students’ acquired knowledge and skills. The approbation of the model, which was carried out inSiberianFederalUniversity from 2015 to 2018, has confirmed its efficiency. The results of the model adaptation are demonstrated in the present article.Practical significance. As presented by the author of publication, the theoretical-methodological bases of fundamental chemical training of the bachelors, enrolled in a wide range of programmes of technical and technological directions, can considerably improve the effectiveness of vocational education and increase the competitiveness of graduates in the labour market.
Studies were carried out on the dissolution of a copper-zinc alloy imitating a base substrate of an electron scrap containing noble metals in nitric-sulfuric acid solutions. A mathematical model is obtained that allows calculating the rate of copper and zinc transition to nitric-sulfuric solutions by varying the concentration of H+ ions from 1 to 4 g-ion / dm3 and NO3 – ions from 0,5 to 1,0 g-ion / dm3. In the range of concentrations of H+ and NO3 – ions studied, the maximum rate of copper transition into the solution is 6,5·10–5, and zinc is 4,5·10–5 kg / m2s. The equation of regression allowing to carry out a choice of conditions for proceeding with necessary speed of the chemical processes taking place in metallurgical practice is presented
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.