EFFICIENCY OF LOW- GRADE COAL PROCESSING DURING METAL SELECTIVE EXTRACTION

Author(s):  
V. Yu. BAZHIN ◽  
A.A. PYATERNEVA
2012 ◽  
Vol 99 ◽  
pp. 120-126 ◽  
Author(s):  
Jun Wu ◽  
Chang Wei ◽  
Xingbin Li ◽  
Sifu Wang ◽  
Mingshuang Wang ◽  
...  

2020 ◽  
Vol 209 ◽  
pp. 05016
Author(s):  
Nikita Pavlov ◽  
Liudmila Takaishvili ◽  
Vasiliy Zakharov

The Republic has significant resources for the development of mining, export and domestic consumption, including the energy needs of the republic and neighboring regions. The article provides a retrospective analysis of the supply of Yakut coal for energy needs and the structure of capacities by energy resources. The estimation of power-generating coal resources, including low-grade products of coking coal processing of the Republic of Sakha (Yakutia), is given. Characteristics of coal deposits are presented, which are useful for energy needs. Projects for the development of coal-fired energy in the Republic of Sakha (Yakutia) are presented. The Republic of Sakha (Yakutia) has significant coal resources for the development of coal-fired power plants. Coal power facilities play a closing role in meeting the demand for electricity and heat. The use of coal for the development of coal-fired energy in the Republic of Sakha (Yakutia) can be determined by the development of mining industry, the construction of power plants of small capacity in isolated areas, as well as the possibility of exporting coal-fired power plants.


2021 ◽  
pp. 23-28
Author(s):  
A. B. Lebed ◽  
R. I. Verkhodanov ◽  
Z. A. Lebed ◽  
A. A. Metelev

Acidic recirculation water and effluents generated by the mining industry and bearing heavy metals can have a significant environmental impact on this region. Due to high concentrations of non-ferrous metals (5.2–300 mg/dm3 Cu; 50–450 g/dm3 Zn), such waters can be used as a raw material for producing concentrates for further recovery of metals from them. This study looked at the recirculation water of the Soryinsk tailings pod, the underspoil waters of the Novo-Shemursk deposit and the Urupsky GOK mine waters. The aim of the study is to develop a process for selective extraction of copper into a product that can be further processed into a final product. The most common techniques used to remove ions of heavy non-ferrous metals from industrial wastewater include neutralization techniques. In this case, however, a considerable share of non-ferrous metals get wasted. At the same time, reagent techniques (e.g. sulphidation in the acidic pH region) enable to selectively extract such metals into concentrates that can then be used in the conventional non-ferrous metal production technology. A sulphur solution in sodium hydroxide was used as a sulphidizer for selective extraction of copper from polycomponent wastewater. The sulphur solution was produced at the temperature of 115–120 oC, the mass ratio NaOH:S of 1:1 and the sulphur concentration of 350 g/dm3. Use of sulphur dissolved in sodium hydroxide helped extract copper in the form of sulphides from complex solutions. It resulted in a high recovery of copper (94–99.9%) and a high-concentration copper concentrate (8.9–27.5%). It was found that iron (III) interacts with sulphide ions forming elemental sulphur, which can be reused for conditioning of copper concentrate in sodium hydroxide. Thus, the sulphur can be reused and the concentration of copper can be increased to 24%. The physical properties of particles in copper sulphide concentrates determine the high rate of solid phase precipitation from the slurry. Sulphide particles are characterized with a high negative charge (–80…–100 mV) and the size of the 90% of the particles reaching 68.9 μm. The authors developed a process flow diagram for extracting copper from low-grade complex solutions. The process involves regular addition of sulphidizer to the existing water flow, detention of a solid copper phase and, when necessary, conditioning of copper concentrate.


2007 ◽  
Vol 20 (7) ◽  
pp. 694-700 ◽  
Author(s):  
Wen-qing Qin ◽  
Wei-zhong Li ◽  
Zhuo-yue Lan ◽  
Guan-zhou Qiu

Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).


Author(s):  
V.K. Berry

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.


Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.


2020 ◽  
Vol 134 (17) ◽  
pp. 2243-2262
Author(s):  
Danlin Liu ◽  
Gavin Richardson ◽  
Fehmi M. Benli ◽  
Catherine Park ◽  
João V. de Souza ◽  
...  

Abstract In the elderly population, pathological inflammation has been associated with ageing-associated diseases. The term ‘inflammageing’, which was used for the first time by Franceschi and co-workers in 2000, is associated with the chronic, low-grade, subclinical inflammatory processes coupled to biological ageing. The source of these inflammatory processes is debated. The senescence-associated secretory phenotype (SASP) has been proposed as the main origin of inflammageing. The SASP is characterised by the release of inflammatory cytokines, elevated activation of the NLRP3 inflammasome, altered regulation of acetylcholine (ACh) nicotinic receptors, and abnormal NAD+ metabolism. Therefore, SASP may be ‘druggable’ by small molecule therapeutics targeting those emerging molecular targets. It has been shown that inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and adverse cardiac remodelling. Therefore, the pathomechanism involving SASP activation via the NLRP3 inflammasome; modulation of NLRP3 via α7 nicotinic ACh receptors; and modulation by senolytics targeting other proteins have gained a lot of interest within cardiovascular research and drug development communities. In this review, which offers a unique view from both clinical and preclinical target-based drug discovery perspectives, we have focused on cardiovascular inflammageing and its molecular mechanisms. We have outlined the mechanistic links between inflammageing, SASP, interleukin (IL)-1β, NLRP3 inflammasome, nicotinic ACh receptors, and molecular targets of senolytic drugs in the context of cardiovascular diseases. We have addressed the ‘druggability’ of NLRP3 and nicotinic α7 receptors by small molecules, as these proteins represent novel and exciting targets for therapeutic interventions targeting inflammageing in the cardiovascular system and beyond.


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