scholarly journals The periclase-chromite refractory decomposition by the action of the pulverized coal and gas medium in course of copper-sulfide raw materials processing

Author(s):  
A. M. Klyushnikov ◽  
E. N. Selivanov ◽  
K. V. Pikulin ◽  
V. V. Belyaev ◽  
A. B. Lebed' ◽  
...  

The investigating results are given for the periclase-chromite refractories' composition and structure which are in contact with the pulverized coal and gas medium in the coppersulfide smelting furnaces. The high-temperature burnt copper concentrate and the sulfur dioxide gas suspensions combined action changes the surface and deep refractories layers chemical composition, with that the impurities content reach the value in weight percent: Fe 54,0, Cu 7,2, Zn 6,4, S 1,8. The refractory's surface layer saturation with the iron and non-ferrous metals oxides decreases the porosity and gives rise to low-melting compositions and eutectics. The refractory decomposition is induced by the shelling of the refractory surface layers with the filled porous taking place in course of the heating-cooling cycling because of the phase's thermal linear expansion coefficients. When the spent refractory disposal, it is feasible to separate mechanically the surface layer for the non-ferrous metals extracting, the rest part can be used for obtaining the refractory powder of various purpose.

Author(s):  
Kseniya Kovaleva

Introduction. The article is devoted to the results of tracing research of things made of non-ferrous metals from the collections of Tsarevskoe, Vodyanskoe, and Mechetnoe settlements, stored in the funds of the Volgograd regional museum of local lore. Method. The author used the method of tracing. The digital microscope DigiMicro 2.0. was used to record the results of observation. Analysis. The author studied 63 products and allocated two large groups: 1) cast products and 2) forged products. The study fixed the following operations for cast products: the use of open and closed molds, casting in composite forms, casting by the smelted model, by the impression, liner casting. In group 2, the following methods of forging were singled out: forming forging, punching, drawing and forging of wire, bending, drawing, twisting, hacking, cutting. Soldering was used to connect the elements. After forming, most of the products passed the subsequent processing associated with the removal of defects (primarily post-casting) and the application of decor (hammering, engraving, stamping, polishing). In addition, the decor could be formed during the creation of the mold (cast decor). Results. As a result of the study, it was noted the use of a wide range of techniques and operations with a comparative technological simplicity for most products. It was also noticed that a few things have been specially prepared for the processing, and it demonstrates the use of secondary raw materials.


2020 ◽  
Vol 24 (5) ◽  
pp. 1105-1112
Author(s):  
Anastasia Vasilkova ◽  
◽  
Alexander Byvaltsev ◽  
Olga Khmelnitskaya ◽  
Grigory Voiloshnikov ◽  
...  

The purpose of the study is to conduct experiments in order to determine the possibility of technogenic gold-bearing raw material cyanidation using ultra-low concentrations of NaCN. Experiments are carried out on the cyanidation of three samples of technogenic raw materials of different composition. The first sample consists of pyrite cinders (Au - 1.8-2.3 g/t, Ag - 13-22 g/t, Fe - 48.52%, Cu - 0.15-0.30%, Zn - 0.3-0.6%). The second sample is represented by the aged tailings of copper-zinc flotation (sample I) with the content of Au - 0.8 g/t, Ag - 7.0 g/t, Fe - 17.2%, Cu - 0.212%, Zn - 0.207%. The next object is the copper-zinc flotation tailings of a concentration plant (sample II), with the following content of Au - 1.22 g/t, Ag - 15.2 g/t, Cu - 0.13%, Zn - 0.23%. It is recommended to use an aqueous wash from non-ferrous metals with subsequent lime treatment as a preliminary processing of pyrite cinders. Cyanidation is carried out at different consumptions of reagent: from 0.075 to 3 kg/t. The experiments have shown that gold recovery in this range of NaCN consumption varies from 42.9 to 44.2%; moreover, a decrease in the reagent consumption allows to reduce the concentration of non-ferrous metal ions in cyanidation solutions. Before cyanidation sample I has also been subjected to aqueous wash to remove acid and non-ferrous metals. NaCN consumption varies from 0.25 to 2.2 kg/t. In this case the extraction of gold amounts to 36.6-46.4%. Cyanidation of tailings (sample II) is carried out in the range of 0.15-1.2 kg/t of NaCN. Gold recovery varies from 24.1 to 30.9%. The cyanidation technology of technogenic raw materials in the field of ultra-low concentrations of sodium cyanide is promising, since it provides acceptable gold recovery under low reagent consumption. For further research in the field of development of an extraction technology of valuable components, the flotation tailings of copper-zinc production (sample II) are chosen as a promising object. It is planned to carry out semi-industrial tests, calculate technical and economic indicators and develop process regulations.


2018 ◽  
Vol 20 (4) ◽  
pp. 706-711 ◽  

<p>WEEE is a fast-growing waste stream that includes potentially hazardous substances, but also valuable secondary raw materials, which can be recovered by adequate recycling and recovery treatment. In the last years, the research interest has moved from the conventional recycling (recovery of ferrous and non-ferrous metals, plastic, glass and other “mass relevant” fractions presented in WEEE), to the innovational recycling, aimed to recover trace elements, such as critical metals (CMs) and rare earth elements (REEs). Currently, the majority of CMs and REEs are lost during the pre-treatment processes. In this paper, an overview of the most relevant e-waste categories and products in terms of CMs and REEs presence, a description of currently applied pre-treatment methods and fate of the observed group of metals during pre-processing phase, as well as general recommendation in order to avoid losses of CMs and REEs within the WEEE treatment chain, are elaborated.</p>


2021 ◽  
Vol 5 (1) ◽  
pp. 84
Author(s):  
Eirini Evangelou ◽  
Georgios N. Anastassakis ◽  
Spyridon Dionysios Karamoutsos ◽  
Athanasios Stergiou

The treatment of Wastes of Electrical and Electronic Equipment (WEEE) is a significant source of secondary raw materials. Ferrous and non-ferrous metals, electronic equipment, and plastics are among these materials. One of the most common metals sourced out of WEEE is stainless steel. Dishwashers are common sources of stainless steel, so large amounts of stainless steel can be recovered from them. In this project, dishwashers were submitted to size reduction via shredding, and the shredded products went through a magnetic separator (which separates all the magnetic ferrous components), an eddy current sensor (which separates all the non-ferrous components) and an induction sorting sensor (which removed all the metallic fractions). This procedure led to the following two streams: one with stainless steel, boards, and cables and another stream mainly including plastic. In the next stage, the stainless-steel stream passed through a high-intensity magnetic separator, leading to a magnetic and a non-magnetic stream. Thereafter, hand sorting was applied to both streams which aimed to increase the recovery from each stream.


2019 ◽  
pp. 11-16
Author(s):  
E. V. Chernousenko ◽  
◽  
G. V. Mitrofanova ◽  
I. N. Vishnyakova ◽  
Yu. S. Kameneva ◽  
...  

2021 ◽  
Vol 13 (2) ◽  
pp. 265-272
Author(s):  
Ivan ALBOROV ◽  
◽  
Fatima TEDEEVA ◽  
Olga BURDZIEVA ◽  
◽  
...  

The article presents the results of research on a comprehensive assessment of techno genic waste deposits located in the North Caucasus region, gives a brief description of the material composition of techno genic raw materials, element-by-element quantitative reserves that are part of the accumulated secondary georesources for their possible utilization, production of non-ferrous metals and raw materials for the manufacture of industrial building materials. The article considers the sanitary and ecological parameters of the functioning of man-made raw materials in complex orographic, meteorological and geographical conditions. The critical aspects of the preservation of techno genic waste deposits in the current anthropogenic conditions are identified. The risk factors for the removal of toxic and harmful geomaterials into the water area with significant harm to the flora and ichthyofaunal are identified. For a deeper assessment of the minerals contained in the extracted ore, a unified state register of techno genic waste deposits should be created, Taking into account the high fragmentation of all the above – mentioned process links at the present time , the owners, taking into account the current sanitary and regulatory requirements, must take adequate measures to ensure the regulatory and environmental requirements in accordance with the current Federal Law “On Production and Consumption Waste”. The need for complex processing of waste from mining and processing industries in the North Caucasus is also dictated by environmental aspects due to the high risk of the occupied territories (they are located in floodplain terraced areas of mountain rivers) due to the flooding of mountain rivers, including the high vulnerability of resort and recreational and balneological complexes due to the negative impact of these negative sources. The assessment of the useful components contained in the extracted ore is currently not carried out in full, and the accumulated waste from processing non-ferrous metal ores is used in small volumes.


2020 ◽  
Vol 299 ◽  
pp. 475-481
Author(s):  
Aleksey A. Darin ◽  
Nail M. Telyakov

The article presents the theoretical basis of sulfatizing roasting in the fluidized bed of oxidic and sulphidic polymetallic raw materials: iron-manganese concretions (IMC) containing non-ferrous metals and pyrite concentrate. The results of preliminary thermodynamic and thermogravimetric studies of IMC of Pacific Ocean and pyrite are described. The results of the laboratory-scale research of sulphatizing roasting of deep-water polymetallic IMC and pyrite concentrates are given. Based on the results obtained, the conclusion is made about the prospects of using the method of preliminary sulfatization for further production of marketable concentrates of manganese and non-ferrous metals.


2020 ◽  
Vol 1 (6(75)) ◽  
pp. 4-8
Author(s):  
F.E. Akthamov

The paper deals with efficient processing of zinc cakes wiht the method of thermo-steaming, which is intended to additional extraction of zinc and a number of non-ferrous metals, as a basis for increasing the complex using of raw materials.


2021 ◽  
Vol 2 (446) ◽  
pp. 81-85
Author(s):  
K. Zhantassov ◽  
Z. Bagova ◽  
G. Turebekova ◽  
B. Sapargaliyeva ◽  
G. Pusurmanova

The object of the study is lead-containing slag dumps from a lead plant. The slags of the lead plant contain a large number of toxic compounds: lead, zinc, osmium, cadmium, which are dangerous sources of environmental pollution. Due to the open storage of slags, it was found that the maximum permissible concentrations of lead were exceeded. Utilization of lead production slags allows to obtain non-ferrous metals and to reduce the technogenic load on the environment as a result of processing of slags. At the same time, slags are valuable raw materials containing compounds of non-ferrous and rare-earth metals. The article proposes methods for the extraction of lead and zinc from slag waste and selects the optimal method for the selective extraction of zinc and lead oxides from dust and slags of lead production. The proposed technology of continuous carbon-free selective extraction of zinc and lead from the dust of electric steelmaking production allows the use of lead production slag, which is fed into a rotating drum furnace in two oppositely directed streams. During the movement of lead slag in the furnace drum and the burning of the torch, lead and zinc are more completely extracted from the dust-like material, where the transporting object is compressed air, and the purified flue gas after the gas is further purified by means of a smoke pump is released into the atmosphere. When using the proposed selective method for extracting non-ferrous metals, the ecological state of the environment will be improved, and it will also reduce the negative impact on human health due to the disposal of toxic slags from lead production.


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