ABSTRACT
During mining, only 4-8% is converted to final products, and the rest is accumulated in landfills. There is a lack of research on the study of various patterns and mechanisms of the formation of cement clinker minerals during the simultaneous distillation of zinc. This paper presents studies of thermodynamic stimulation of environmental and population protection by utilization of technogenic enrichment waste as secondary raw materials for clinker production and zinc extraction. In particular, a comparison of the Gibbs energy (ΔG) of clinker formation under standard chemical equations and under non-standard chemical equations is given. According to the results of the study, using thermodynamic simulation, the temperature intervals of mineral formation, the dependence of the Gibbs energy on temperature (ΔGT°), and the approximation equations were found; it was established that the presence of zinc ferrite contributes to the intensification of the formation of clinker minerals and the extraction of Zn to gas.
ABSTRACT
In the study, experimental and theoretical studies were carried out to assess the influence of the shapes of dents in the tank wall on the stress-strain state of the defect zone. By testing fragments of a cylindrical tank, it was found that the most appropriate expression is (5), which could take into account the leaching of the tank wall, resulting in a decrease in the stress concentration index. At the same time, during theoretical studies in this paper, it was found that polynomials determined the stress concentration coefficient, where the obtained analytical expression data were compared with the data determined numerically in the ANSYS program, and it was found that the spread was from 2% to 10%. According to the results of a numerical study of the stress-strain state of the dent zone in the tank wall, graphical dependences of the stress concentration coefficient on the dimensionless depth of the dent for various values of the dimensionless radius of the dents and do not exceed 2% of the indicators that are obtained. At the conclusion of the experimental and numerical studies, a conclusion was made about the degree of influence of the geometric dimensions of the dents on the stress concentration index.
ABSTRACT
The paper presents the results of experimental studies of the features of the operation of prestressed shells, taking into account the various structural parameters of the prestress. It is established that when the winding angle changes from perpendicular to the shell axis to 75° and 65°, the circumferential stresses decrease 1.4 times and 1.2 times, respectively, and the axial stresses increase five and three times, which are two and four times lower than the circumferential, from which it can be concluded that the reduction in the winding angle to the longitudinal the axis of the shell has a positive effect on the stress state of the structure. The study also found that with an increase in the diameter of the winding wire from 1 to 2 mm and a change in the winding angle, the same nature of the stress distribution is observed, but the values of the stress state parameter change, so the efficiency increases up to 25% due to an increase in the winding thickness, depending on the pitch, angle and thickness of the winding, which favorably affects the strength and the bearing capacity of the structure as a whole by increasing the value of the stress state parameter. Thus, the results of the analysis will allow us to use in more detail the possibility of controlling the stress-strain state of the prestressed shell by changing the design parameters, and the results obtained can be used in design or construction, as well as when increasing the strength characteristics of the structure, which allows us to create a high-tech design optimal for these operating conditions, which can positively complement the studies conducted earlier in this direction.
ABSTRACT
This paper presents studies on the possibility of utilization of technogenic waste from the metallurgical industry by the method of complex processing in order to reduce the anthropogenic load on the environment of the region with the example of the zinc silicate-magnetite-carbon system. The selected sample of clinker dump from welting was subjected to chemical and scanning electron microscopic analyses and thermodynamic modeling. Thermodynamic studies were carried out in the temperature range 1600-2200 K and pressure p = 0.1 MPa, modeling the process of electric melting of clinker from welting in an arc furnace using the software application Astra 4 developed at the Bauman Moscow State Technical University (Moscow, Russian Federation). As a result of the thermodynamic modeling, the optimal temperature range was established, which was 1800-1900 K. Thermodynamic studies established that it is possible to drive away zinc from the system under study by 99-100% in the entire temperature range under study. The maximum degree of silicon extraction (αSi) in the alloy is up to 69.44% at T = 1900 K, and the degree of iron extraction (αFe) in the alloy is up to 99.996%. In particular, it was determined and proved that clinker waste from welting can act as a secondary technogenic raw material when it is processed as a mono mixture to produce iron silicides with a silicon content of 18 to 28%.
