METALLURGY, MATERIAL SCIENCE, MINING ENGINEERING

Proceedings

METALLURGY, MATERIAL SCIENCE, MINING ENGINEERING

N:2

2019

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Dear readers,

         We introduce the next issue of the NPUA Proceedings - "Metallurgy, Material Science, Mining Engineering" devoted to investigations in metallurgy, material science and natural resource exploitation.

         The earth of Republic of Armenia is rich in various metallic, in particular copper, molybdenum, gold, lead, zinc, iron, minerals, and non-metallic (tuff, basalt, marble and granite) minerals which are of large volumes at present. From that point of view, a special attention is paid to the conceptual framework of subsoil use. The specific features in the sphere of investigation and development of the earth are introduced.  The objective solution of the problems of exploration and optimal development of subsoil is possible only with the close combination of geological, technical, technological, environmental and economic aspects;

In the field of exploration and development of subsoil, one of the most fundamental regulatory documents is the “Classification of reserves of deposits and forecasted resources of solid minerals”, which is designed to develop the common requirements for the study of deposits, to help reduce the risk of investments during their development to reasonable limits, to protect both the interests of the state - the owner of the subsoil, and the investor.

Dear reader, the editorial board is making the first steps to include the journal   “Proceedings of National Polytechnic University of Armenia - Metallurgy, Material Science, Mining Engineering" in the databases “Scopus” and “Web of Science”. In this connection, the rules for preparing the manuscripts have been slightly corrected as introduced at the end of the journal. We expect from you new materials on your recent research and innovative developments.

The electronic versions of the papers can be found in the site innovative.polytechnic.am (i.polytechnic.am).

Headings

  • группировка

  • конструкция

  • материалы.

  • нанодатчики

  • принципы и механизмы работы

The constructive features of nanosensors for the oil industry are shown. Nanosensors usually include three main elements: the receptor layer, the measuring transducer, as well as the systems of amplification, processing, transmission and display.

The classification of nanosensors by the principles and mechanisms of operation is given according to which all nanosensors are divided into two large classes: nanodevices, which, on the basis of manifestation of the existing physical principles and mechanisms, transform the external influences of different nature and degree of manifestation into separate electrical operating signals; photometric and chemical nanosensors, which in most cases, directly interact with the substance molecules or electromagnetic fields.

Types of nanosensors based on various materials are presented. The characteristic features and principles of action of nanosensors based on carbon nanotubes, polymers, fluids, metals and other materials are introduced.

Nanosensors functioning on the basis of sensitive polymers and metals are grouped.

The first are divided into three main groups: devices with sensitive elements, containing a coating of only one type of polymer; devices with sensitive elements, containing a coating of a polymer of one type with a layer of another material applied onto it; devices with sensitive elements, containing a coating of a composite material based on polymers.

The second are divided into three main groups: sensitive elements which have a coating of metal oxide only; sensitive elements which contain a coating of a layer of metal oxide with a layer of another material; sensitive elements which have a coating of a composite material based on a metal oxide.

The structures of nanosensors of pressure, temperature and chemical composition of the studied fluids are revealed.

  • выщелачивание

  • извлечение.

  • молибден

  • обжиг

  • оптимальные параметры

  • переработка

  • рений

  • технология

 

In Armenia, the pace of metallurgical production falls behind mining. In this regard, and taking into account the present resources in the country, the development of metallurgy is of utmost importance. The basis of this problem is not only the possibility of expanding investments, which is caused by the lack of financial resources, but also the lack of processing capacities. If this problem has solutions in the frame of the first above-mentioned item, in the second - some improvement in standard technologies and technological solutions, as well as the study of new types of processes due to the characteristics of local raw materials is required. The availability of the technology for the complex extraction of valuable (molybdenum, rhenium) and other related metals from the ore raw materials will create the necessary prerequisites for local investments and organization of a full production cycle for molybdenum processing in place.

An attempt is made to substantiate the process of burning the molybdenum concentrates in the presence of calcium oxide in the laboratory. The optimal burning parameters (temperature - 550…600 ºC, the holding time - 90 min) have been determined, at which sulphur trioxide does not pass onto the gas phase and non-evaporating compounds of calcium molybdate and calcium perrhenate are formed in the roasted product. The basic optimal parameters of the leaching process in an aqueous solution of soda are researched (the Na2CO3 concentration of 200 g/dm3, the holding time – 60 min, temperature - 90ºC, ratio of the solid and liquid phases - 1:4). Leaching the obtained roasted product in an aqueous solution of soda provides a 98% extraction of molybdenum. The laboratory investigations have shown that burning of molybdenum concentrate in the presence of calcium oxide makes it possible to develop a fundamentally new, ecologically pure technology for molybdenum and rhenium extraction.

  • концентрат

  • сульфатизирующий обжиг

  • сульфиды

  • термодинамика

  • технологический режим.

The thermodynamic analysis of sulphatizing roasting of lead-containing sulphide concentrate to extract lead and related valuable metals from it by using the hydrometallurgical method. Talking into account the fact that in such sulphide concentrates some minerals, especially galena (lead sulfide mineral), sphalerite and chalcopyrite are so closely interconnected that it is completely impossible to extract them separately under the usual production cycle, the universal technology of the sulphidizing roasting of sulphide concentrate in the general technological processing cycle is proposed. The “Sulphatizing roasting leaching and cementation for the extraction of all valuable metal extraction” is experienced. It is shown that during the roasting process, sulphides of lead, copper and zinc, as well as iron, are successfully converted to sulphates of the corresponding metals which are easily soluble in water solutions, which is a good prerequisite for complex and efficient hydrometallurgical extraction of lead and other related metal components. A more optimal technological mode of roasting is recommended ensuring the production of complete sulphate cinder for subsequent leaching. The proposed technological solution has a simplicity and versatility in terms of its applicability for any sulphide concentrate, including copper, zinc sphalerite, sulphide-lead and a number of other sulfide concentrates used to extract valuable metals from them.

  • боковые линии

  • деформированный слой

  • кристалл-монохроматор.

  • расходимость пучка

  • рефлекс

  • топограмма

The structure of reflexes has been investigated in the case when there are surface deformed layers in the crystal, depending on the character of absorption and dispersion of X-rays by the deformed layers, the main volume of the crystal and beam divergence. It is experimentally proved that if there are surface deformed layers, the structure of reflexes (thin lines, straight and figured lines of central part) depends on the beam divergence and the character of absorption and dispersion of X-rays by the deformed layers and the main volume of the crystal. It is shown that the presence of surface deformed layers is a necessary but not sufficient condition to form thin sidelines on the sectional topogram. Sectional topograms from both thin and thick step crystals have been obtained with polished surfacs of entrance and exit. It is established that thin lines on sectional topograms are the result of kinematic dispersion of X-rays in the surface deformed layers, and the middle wide line (the main reflex) is the result of dynamic dispersion in the main part of the crystal. The reduction of the divergent diffractive beam has been investigated with the help of asymmetrically carved crystal-monochromator working on reflection, and also the increase in the distance between the focus of the X-ray tube and the studied sample. It is shown that even in the case of big expositions, thin lines are absent on the topograms, the wide component of dynamic dispersion is too black. It is experimentally proved that for forming thin sidelines of reflex due to the surface disturbed layers, the divergence of the primary beam is a necessary condition.

  • зев

  • обрывность

  • основные нити

  • факторный эксперимент.

The article is devoted to the study of the parameters of the fabric obtained in production on air-rapier weaving machines, using a new method protected by copyrights. The peculiarity of the method is that on air-rapier weaving machines, in one rotation of the main shaft, instead of one, two weft threads are laid simultaneously in the throat.

Fabric production is a complex technological process and requires consistent constant control. To ensure the quality of the fabric, the study of the breakage of the main threads plays an important role in order to adjust properly the parameters of the throat.  

The paper presents the results of the study of the breakage of the main threads in the process of obtaining fabric by the method of simultaneous laying of the wefts in the throat. The aim of the work is to determine the optimal values of the parameters of the process of developing a new fabric, in which the breakage will be minimal. To determine the optimal parameters of the throat, a full factorial experiment 23 was used. The parameters of the study are the size of the spade, the length and height of the throat, which have the maximum effect on the rate of the breakage of the main threads.

As a result of experiments, in the process of fabric formation weave in the main reps 2/2, when laying two simultaneous wefts in the throat, the minimum number of breakages of the main threads in the following parameters is ensured: the value of the spade - 3350, the height of the lifting heddles (throat height) - 40 mm, the throat length - 250 mm.

  • клей

  • кожа

  • обувь

  • подошва.

  • прочность крепления

The results of statistical control of testing the durability of gluing the soles are elucidated. The test of footwear for the durability of fastening the bottom was carried out by two methods: by the sole separation on a dynamometer, and by the bending action of the tooth on the edge of the sole in three points up to the first sign of destruction. The study was performed in 2 and   24h after the footwear was taken off the press. It is established that from the first days of statistical control, when at testing on the standard of loading of separation appeared below the time norm, the durability of gluing the soles steadily increased. Such a phenomenon is also observed as a result of a test by means of a manual device. The analysis of the nature of separation of soles shows that loadings below the norm are caused by non-compliance with the technological mode: the insufficient width of a long edge, the insufficient warming up of the glue film. It is shown that at setting standards, it is necessary to be guided by the fact that the premature separation of soles regarding a sock is caused not so much by the weakening of the pasting as a result of uneven pressure in the press or the existence of folds on a long edge of a sock, but because of the strengthened impacts on this part in operational conditions. The following conclusions are introduced, when fastening a bottom with the use of glues, the statistical way of control of durability is one of the most effective in terms of prevention of release of footwear of a defective quality; sharp fluctuations of loadings of separation of soles on a dynamometer at a coefficient of variation equal to 21-25% do not allow to be limited to tests of single pairs of shoes and each change; to avoid the destruction of a large number of samples and, at the same time, to provide the release of footwear of sufficient durability of gluing of a bottom, it is necessary, along with the test of single samples on a dynamometer, to force the introduction of a way of test without the destruction of footwear.

  • изгиб

  • кручение

  • разрыв.

  • растяжение

  • удлинение

  • элементарная нить

  • неравномерность

In the process of twisting, the filaments are arranged along a helix, while experiencing torsional deformations, bending and stretching. At that the stretching deformation conditions the interpressure,  the change of the cross section (compression)  of filaments in the places of contacts and the friction force on the contact surfaces. In the process of twisting, complex geometrical and mechanical transformations of the system of filaments into a twisted yarn take place. The resistance to tearing of a twisted filament is determined, firstly, by the resistance to breaking the system of filaments, and secondly by the resistance of frictional forces on the surfaces of contact of all the filaments with one another. These characteristics are necessary for determining the optimal operating conditions for reheating and sizing machines, as well as for weaving looms, using a system of twisted yarns. The size of the irregularities and the character of the unevenness of filaments and twisted yarns in thickness, tensile load, elongation and other characteristics are determined by the correlation function, the spectral density and the gradient of the unevenness. The dynamic system of the torsion process in the formation of a single-filament yarn of two elementary filaments is presented as an object with four impacts and two reactions. The first two actions X1(t), X2(t) characterize the change in the breaking load and the elongation of one elementary filament; X3(t), X4(t) is the same for another thread. The reaction Y2(t) characterizes the change in the breaking load of a twisted yarn along its length, and the reaction Y1(t) is the elongation at the break of this thread in successive sections of this thread. Since the scheme of the relationship between the two reactions with four impacts is the same, the methodology for determining this relationship is also the same.

  • классификация

  • комбинированная разработка

  • месторождение.

  • полезные ископаемые

  • освоение недр

Specific features in the study and development of subsoil are introduced, allowing to draw the following conclusions:

  • an objective solution of the tasks of exploration and optimal development of subsoil is possible only with the indispensable close combination of geological, technical, technological, environmental and economic aspects;
  • the economy of subsoil use is most complex.

Condition parameters are a tool for contouring and calculating the mineral reserves and the components contained in them. With their use, reserves are divided into balance sheet and off-balance sheet. It is easy to verify that the optimization of condition parameters requires the optimization of solutions of literally all technical, technological and economic problems.

Over time, this value increases many times due to the exhaustion of mineral reserves and the growth of their consumption. The growth in world consumption is due to two reasons:

  • the steady population growth;
  • the growth of specific consumption, especially in developing countries.

The article reflects the specific features in the field of research and development of subsoil. One of the significant drawbacks of exploration of ore deposits is excessive cost savings for technological studies of ore dressability, which does not allow, in particular, to substantiate the dependence of the content of useful component in the tailings θ on its content in ore α.

In the field of exploration and development of subsoil, one of the most fundamental regulatory documents is the “Classification of reserves of deposits and forecast resources of solid minerals”. The significance of classification is difficult to overestimate. It is designed to develop common requirements for the study of deposits, to help reduce the risk of investments during their development to reasonable limits, to protect both the interests of the state - the owner of the subsoil, and the investor.

  • комплексное освоение

  • оп¬ти¬маль¬ная годовая производительность.

  • целевая функция

  • месторождение

The impact of the degree of complex development of deposits on the optimal annual pro­duc­tivity of a mining and metallurgical plant (MMP) is considered. The optimal annual pro­duc­tivity of a MMP for the complex development of deposits at different degrees of wast utilization of the mining and metallurgical production is substantiated. The following cases are considered: a) the need for recyclable waste is limited; b) the need for recyclable waste is practically unlimited; c) overburden rocks are partially utilized, and tailings and metallurgical slag are completely utilized. Based on the optimality criterion, a ge­neral objective function is for­mu­la­ted, which “maximizes the algebraic sum of the effects of the main (mining and processing of mineral resources) and incidental (disposal of mining and metallurgical production waste products - overburden, enrichment tailings and metal­lur­gi­cal slag) production and environmen­tal damage environment (alienation of land for waste sto­ra­ge)”. Formulaе are derived for de­ter­mining the effects of the main and associated industries, as well as the total price of land for storage of mining and metallurgical waste. Based on the derived formulaе, a new objective function is formulated. Equating the first derivative of the newly obtained objective function with respect to the annual productivity of the MMP A to zero, the optimum annual productivity of the MMP is substantiated, taking into account the integrated deve­lop­ment of deposits and environmental aspects. The resulting formula makes it possible to deter­mine the optimal annual production capacity of the MMP, at which the differential rent or excess profit for the entire period of development of the deposits will be maximum, taking into account the integrated de­ve­lop­ment of mineral resources and environmental issues. The graph shows the dependence of the optimal annual productivity of MMP on the degree of utilization of overburden for a con­di­tio­nal example. It is established that: 1) the degree of optimal annual productivity of the MMP is significantly affected by the degree of integrated development of the subsoil and the amount of excess profits from waste disposal of mining and metallurgical production; 2) with incomp­lete waste disposal with an increase in annual excess profits from the sale of by-products, the op­ti­mal annual productivity decreases.

  • акустическая жест¬кость массива.

  • крепость породы

  • структурное строение

An analysis of the current state, and the prospects for the development of open pit mining in ore quarries is carried out. In ore quarries, and ore massifs, as a rule, have different fracturing and rock strength according to the scale of  M.M. Protodyakonov equal to f = 8..20. The development of these rocks is carried out using drilling and blasting operations with a significant consumption of explosives. The effectiveness of blasting in the development of ore deposits depends on many factors. The main indicators affecting the quality of the explosion are: the strength, fracture and structural composition of the exploding array. In this regard, when conducting blasting operations in ore quarries, it is necessary to, take into account the physicomechanical properties and structural features of the exploded massif. By the examples of the Ararat and Aramus open pits, the possibility of regulating the degree of fragmentation in fractured massifs is considered. The calculation results for the choice of the type of the explosive, depending on the acoustic stiffness of rocks are given. The areas of application of explosives on the explosive rocks are established. Based on the theory of the wave action of the explosion when blasting two well charges, the radius of the zone of controlled crushing, and the grid of the wells are determined. The optimal values ​​of the delay interval are theoretically and experimentally determined.  The ceteris paribus, the optimal value of the slowdown interval for light-explosive rocks 60...80 msec, and for medium- and hard-breaking rocks, 40...60 msec and 30...50 msec, respectively have been established.. It has also been established that the use of a diagonal blasting scheme with a trapezoidal cuts makes it possible to more effectively control the quality of crushing and the form of the collapse of the exploded rock. A new blasting technology has been proposed which allows to obtain a compact collapse of the blasted rock mass, and to reduce the output of substandard fractions.

Council

Editorial Council of Proceedings: Yu.L. Sargsyan (Editor-in-chief, doctor of tech. sciences),           A.Kh. Grigoryan (vice Editor-in-chief, doctor of tech. sciences), A.G. Avetisyan (responsible secretary, doctor of tech. sciences), S.G. Aghbalyan (doctor of tech. sciences), M.K. Baghdasaryan (doctor of tech. sciences), B.S. Balasanyan (doctor of tech. sciences), V.Z. Marukhyan (cand. of tech. sciences), S.H. Simonyan (doc­tor of tech. sciences), A.V. Tadevosyan (cand. of  tech. sciences)

Editorial Council of the Journal: S.G. Aghbalyan (Editor-in-chief of the journal, doctor of tech. sciences), L.Ye. Sargsyan (vice Editor-in-chief of the journal, doctor of tech. sciences), A.A. Petrosyan (responsible secretary of the journal, cand.of tech. sciences), Yu.A. Aghabalyan (doctor of tech. sciences), N.S. Garibov (doctor of tech. sciences),  S.G. Mamyan (doctor of tech. sciences), L.A. Manukyan (doctor of tech. sciences), V.H. Martirosyan (doctor of tech. sciences), G.S. Hovsepyan (doctor of tech. sciences),      A.M. Hovhannisyan (doctor of tech. sciences), A.H. Hovhannisyan (doctor of tech. sciences), H.S. Petrosyan (doctor of tech. sciences) 

  Editors:   Zh.S. Seyranyan, H.Ts. Petrosyan, H.Z. Ghazaryan

 © National Polytechnic University of Armenia (NPUA) “Tchartaraget” Publishing House

     Address: 0009, Yerevan, 105 Teryan, NPUA

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