Smelting options for carbon ferrochrome based on ore raw materials, middlings and their technological evaluation

The article presents the results of large-scale laboratory tests carried out in the conditions of the Chemical and Metallurgical Institute named after V.I. Zh. Abishev on the use of briquetted mono-charge in the smelting of carbon ferrochrome on a 250 kVA furnace. The purpose of these studies was to determine the technological parameters of the use of briquetted mono-charge containing in its composition chrome ore, wastes from the production of high-carbon ferrochrome, middlings and various carbonaceous reducing agents. The main idea of using these briquettes was to multiply the contact surface of the reductant and ore, which should speed up the technological process. The principal possibility of smelting a standard alloy using briquetted mono-charge is shown. The alloy for individual charge options meets the requirements of the standards. In comparison with the technology without the use of briquettes, the mono-charge technology has shown advantages in all main parameters. The technology with the use of briquettes from the dust of the AktZF gas cleaning system is distinguished by a low yield of non-standard metal and slag, the bulk of the material goes into the gas collection system. Technologies from briquettes from fines pellet production area of Donskoy ore mining and processing plant and flash have very low specific technical and economic indicators and cannot be recommended for industrial use. Improvement of briquetting modes and technology of their smelting is required. The technical and economic indicators were higher than the current one, showed briquettes from ore and coke of the People's Republic of China, briquettes of ore from borlin and shubarkol coals of Kazakhstan.

Synthesis and characterization of new biodegradable gels based on 2,2 '-(ethylenedioxy) diethanethiol and pentaerythritol triacrylate

The work is devoted to the synthesis and characterization of gels based on the monomers pentaerythritol triaacrylate (PETriA) and 2,2 '-(ethylenedioxy)diethanethiol (EDODET) by thiol-ene "click" polymerization. The properties of the obtained gels were investigated by IR, Raman spectroscopy, mechanical analysis. Sol-gel analysis of obtained networks was carried out and the degradability was investigated. The results of IR spectroscopy confirmed the presence of -C = O and -C-O-C- groups in the composition of the obtained gels. The presence of unreacted C = C bonds conjugated with C = O, as well as thiol groups, varies depending on the composition of the initial monomer mixture (IMM). Raman spectroscopy results correlate well with IR data. Raman spectra also show C-S, S-S and SH characteristic bands that are difficult to identify by IR spectroscopy. It was found that the composition of MM affects the physicochemical properties of the synthesized gels. The highest yield of the gel fraction of obtained polymers was found in samples with an equimolar composition of IMM. The analysis of mechanical properties showed that gels with an excess of PETriA exhibit more elastic properties, and an excess of EDODET leads to the formation of networks with a higher crosslinking density. The study of the ability of obtained PETria-EDODET gels to degrade in a 3% solution of hydrogen peroxide showed that the polymer network degrades by 12% within 60 days. This property of the obtained gels can find application in the creation of targeted drug delivery systems with their prolonged release.

Hybrid Sorbents for Removal of Arsenic

The paper analyzes data on the removal of arsenic by sorption methods using materials that have prospects for large-scale application in water treatment. These materials include transition metal oxides in the micro- and nano-dimensional form, including those in the composition of composite materials with inorganic matrices, or hybrid sorbents in the composition with polymer resins or natural biopolymers. Examples of the use of composite (hybrid) sorbents for the removal of arsenic from solutions with low concentrations (at the level of MPC) are given. The objective of this article was to sum the up-to-date information about the most important features of chitosan-containing and chitosan-carbon materials we developed in view their use in arsenic removal processes at low concentrations to concentrations that meet WHO requirements. The paper presents data on the sorption properties of Mo-containing activated carbon fibers and chitosan-carbon composite materials towards arsenic (V) when it is extracted from bidistilled and tap water under static and dynamic conditions. The factors of the different behavior of the sorbents depending on the form of a biopolymer deposited on the fiber and the stability of the sorbents during the sorption of arsenic are discussed.

The effectiveness of the kit portable PLC on electrical motors course among vocational school students in Aceh, Indonesia

This research aims to test the effect of the kit Programmable Logic Controller (PLC) on the achievement of vocational school students' competencies in electrical motor control courses for form 3 students in Aceh, Indonesia. Constructivist theory and Bloom's Taxonomy are referenced in this study in relation to learning. While the ADDIE model is used in relation to product development. This study used a quasi -experimental design with pre- and post -tests. The population (N = 333) in this study was level 3 vocational students in Aceh, Indonesia. The number of samples was 98 people, consisting of the experimental group (n = 50) and the control group (n = 48) selected by cluster random technique. The instruments used in this study included pre- and post -test interview protocols. The values of the KR20 reliability coefficient of the question items on the knowledge aspect were 0.97 and 0.81 on the skills aspect. The results of the descriptive analysis found that the experimental group (mean = 64.08; SD = 4.548) showed better competency achievement than the control group (mean = 63.06; SD = 5.487). The result of hypothesis test using Mann Whitney test is [Asymp. Sig. (2-tailed) = .000, p <0.05] which means that the teaching aids developed have successfully had a positive effect in improving the achievement of student competencies. The implications of this study have produced a teaching aid that can be used as a template by teachers to build teaching aids that are more affordable, easy and safe to use so that they can be motivated to innovate in learning and become a new career opportunity. Given that the Covid-19 epidemic has affected face-to-face learning, the proposal for further research is the need to integrate logic control programming (PLC) learning aids into a technology-based learning trend. Researchers, on the other hand, suggest a broader scope of study whether teachers and students in a wider area and other fields of knowledge related to the utilization of PLC programming.

Assessment of the influence of the structural characteristics of granular systems of microsilicon on the properties of thermal insulation materials

The article discusses experimental studies of the size and shape of structured particles of microsilica small angle x-ray scattering method and a photophonon theoretical description of the heat transfer process in complex heterogeneous structures to assessment of the structural characteristics of granular systems for the properties of thermal insulating materials. The mechanism of heat transfer in granular, porous systems is quite complex, since heat exchange occurs in a material consisting of two phases (solid and gas) and at the phase boundary. Heat transfer in liquid thermal insulation coatings can be carried out from one solid particle to another. In this case, the thermal conductivity will depend on: the chemical and elemental composition of the material; particle granulometry; surface topology - the presence of inhomogeneities, defects on the surface; the number of touches and the contact area between the particles. The heat transfer of gas in the pores is carried out when gas molecules collide. Thermal conductivity will be determined by the ratio of the free path of molecules and linear pore sizes, temperature and dynamic viscosity of the gas phase, the nature of the interaction of gas molecules with the solid phase. Heat transfer by radiation depends on the nature of the particles, the dielectric, magnetic permeability and the degree of blackness of the particle surface. Based on the analysis of possible mechanisms of heat transfer in granular systems, it can be argued that the effective thermal conductivity of the system depends, all other things being equal, on the structure of the pore space of granular materials, topology and the number of particle touches. Considering idealized models of the structure of granular materials in the form of ordered folds of perfectly smooth balls, we can obtain several variants of structures: with tetrahedral; hexagonal; cubic packing of balls.

Studies of the rate of gold sorption by the AM-2B anionite from cyanide-alkaline solutions

The paper presents the results of studies on the sorption leaching of gold-containing ore of the Vasilkovskoye deposit. Kinetic dependences of the sorption of gold and associated metals from cyanide-alkali solutions under different physical and chemical factors were obtained. It was found that gold on the AM-2B resin sorbed at a higher rate than, for example, copper and zinc. The solutions were analyzed using modern devices of a new generation: FT-IR spectrometer "Avatar 370". Laboratory studies were performed to determine the gold sorption rate by the AM-2B anionite from cyanide-alkaline solutions. It was found in the process of sorption of gold from multicomponent cyanide-alkali solutions on AM-2B anionite of mixed basicity, with the macroporous structure containing benzyl dimethylamine and dibenzyl dimethyl ammonium functional groups, that an important factor of qualitative and quantitative separation of gold and impurity metals is the concentration of cyanide and hydroxyl ions in solution. The temperature effect on the sorption rate of gold from cyanide-alkali solutions was studied with the temperature dependences F of t, Bt, of t, ln (l - F) of t, and D of t that show that the sorption process of dicyanoaurate ions is controlled by mixed diffusion.

Study of the horizontal sidetracking efficiency using hydrodynamic modeling (on the example of a Kazakhstani field)

One of the modern approaches for the effective development of small deposits is the construction and operation of wells with a complex architecture: horizontal wells (HW), sidetracks (BS, BGS), multilateral wells (MLW). Sidetracking makes it possible to reanimate an old well that is in an emergency state or inactivity for technological reasons, by opening layers that have not been previously developed, bypassing contamination zones, or watering the formation. This study examines the possibility of using horizontal sidetracks in the operating wells of the field of the Zhetybai group. To select the optimal length of the horizontal sidetrack of the wells, graphs of the dependences of the change in flow rate versus length of the horizontal well were built, taking into account the pressure losses due to friction. It can be seen from the dependence of NPV versus length of the horizontal wellbore that the maximum NPV is achieved with a horizontal wellbore length of 100 m. A further increase in the length of the horizontal wellbore leads to a decrease in NPV. This is due, firstly, to a decrease in oil prices, and secondly, interference of wells, a small number of residual reserves, and a small oil-bearing area. As a result of a comparison of technical and economic criteria, the optimal length of a horizontal wellbore is from 100-300 meters. Comparison of the flow rates of vertical wells and wells with horizontal sidetracks showed a clear advantage over the latter in all respects.

Fluoroammonium method for processing of cake from leaching of titanium-magnesium production sludge

We present the results of the physical and chemical properties of cake from nitric-acid leaching of titanium production sludge. It was found that all silicon in the cake is in the form of quartz, albite, sillimanite, sodium aluminosilicate. In total, these minerals make up the majority of the cake 60.24%. Titanium is presented in the form of rutile, titanium aluminum oxide, which in total is 35.56%. Iron is part of sillimanite and hematite, the total content of which is about 4.2%. The optimal parameters of fluoroammonium processing of cake were determined: silicon distillation into sublimates at 300°С for 6 hours, sublimation of titanium in the form of titanium tetrafluoride at 800°С for 2 hours. The process of alkaline hydrolysis of sublimates of fluoride compounds and cinder was carried out. Purification of impurities and calcination of hydrated titanium dioxide were carried out. The resulting titanium and silicon dioxide products contain: 96.2% TiO2, 88 % SiО2, respectively; a niobium-containing intermediate product with a content of 11.6 % Nb2O5 was also obtained.

Determination of optimal oil pumping plans

This paper presents the results of determining the optimal plans for pumping oil through the main oil pipelines of Kazakhstan. The calculation methodology is based on determining the minimum unit cost of pumping depending on oil flow rate. Oil pumping energy-saving modes are determined under optimal operating conditions of pumping units and heating furnaces at stations. Determination of the optimal pumping plan is implemented as a separate module of the SmartTranPro software. Pumped oil volumes on the oil pipeline sections were determined on the basis of the automated system of control and metering of electrical energy data of KazTransOil JSC. Optimal pumping plans for monthly oil volumes in the Kalamkas – Karazhanbas and Dzhumagaliev – Atasu pipeline sections for cold and warm periods were calculated on the basis of the found dependence of the pumping unit cost. For each range of oil mass flow rate, specific costs for oil pumping and a list of operating pumps at oil pumping stations located along the pipeline section are indicated.

Features of the crystallization of AlCl3·6H2O in the system AlCl3 – MeClx – HCl – H2O

A laboratory setup has been developed to study the regularities of crystallization of aluminium chloride hexahydrate from hydrochloric acid solutions. The influence of the AlCl3 content in the initial solution, the consumption of gaseous HCl, and the behavior of impurities on the crystallization of AlCl3·6H2O from aluminium chloride solutions of leaching cinder obtained as a result of chlorinating ash burning from thermal power plants in Kazakhstan have been studied. The behavior of impurity metals in the process of crystallization of aluminium chloride solution has been studied, and their distribution between the products of the crystallization process has been established. It is shown that aluminium chloride content in the solution decreases with an increase in the consumption of hydrochloric acid. It was found that under the conditions of crystallization of AlCl3·6H2O, all impurities, except for barium, pass by 98% into the mother liquor. To reduce barium and other impurities in the obtained crystals of AlCl3·6H2O, it is proposed to carry out multiple washing of the crystals with hydrochloric acid (32% HCl). It has been shown that a decrease in the acidity of the washing solution from pH = 10 to pH = 5.5 ensures the isolation of ACH crystals with a minimum content of impurity metals, ppm: 3-5 Ca; 3-6 Fe; 1-3 Mg; 0.1-0.5 Ti; 1-3 Na; 20-30 P2O5. The moisture content of the obtained crystals is 4-5%; the particle size is 400-900 microns. As a result of mathematical processing, regression equations were constructed that adequately predict aluminium chloride content in the solution and its extraction into crystalline hydrate, depending on the consumption of hydrochloric acid. The optimal parameters of the crystallization process have been established: Т = 60 ºС, HCl concentration in the solution - 26-30%, HCl gas consumption = 0.5 l/min, duration 1 hour.