scholarly journals Use of mechanical activation in the processing of gold-bearing ores and anthropogenic materials

2020 ◽  
Vol 192 ◽  
pp. 02017
Author(s):  
Natalia Litvinova ◽  
Aleksandra Kopylova ◽  
Valentina Stepanova ◽  
Hitachi Tatsumi
Keyword(s):  
Mechanical Activation ◽  
Alkali Metals ◽  
Chemical Elements ◽  
Experimental Studies ◽  
Accessory Mineral ◽  
Complexing Agent ◽  
Activation Process ◽  
Eastern Region ◽  
Trace Impurities ◽  
Gold Bearing

The results of experimental studies on the use of mechanical activation in the processing of ores and anthropogenic materials of the Far Eastern region are presented. The effectiveness of the use of electrophotoactivated solutions and complex reagents at the stage of mineral preparation has been established. Technological solutions have been proposed to reduce the loss of finely dispersed and chemically bonded gold during the processing of gold-bearing materials based on a directed change in the properties of the surface of minerals. The effectiveness of the use of the mechanochemical activation process for various aspects of the technological chain has been experimentally confirmed – a decrease in the sorption properties of materials, development of microcracks in oxidized ores for the penetration of leaching solutions into mineral aggregates, oxidation of the surface of primary ores, and removal of films from the mineral surface. Indicators of technological refractoriness of the studied ores and anthropogenic materials were revealed – a high proportion of chemically bound gold with atoms of basic and accessory mineral-forming elements, the presence of grains of the valuable component covered with oxide films, enclosed in carbonates, quartz and waste rock. The refractoriness of ores is confirmed by a high sorption capacity (the predominance of carbonaceous and clay matter), the presence of trace impurities in gold (Sb, As, Cu, Fe, Hg), which increase the consumption of cyanide during leaching. The material composition is dominated by a significant amount of chemical elements – cyanosides, actively interacting with the main complexing agent of leaching solutions – cyanide of alkali metals.

scholarly journals EVALUATION OF TOXIC EFFECTS OF MAGNETIC CONTRAST DIAGNOSTIC GADOLINIUM-CONTAINING NANOCOMPOSITE

2019 ◽  
Vol 98 (10) ◽  
pp. 1161-1165
Author(s):  
Larisa M. Sosedova ◽  
E. A. Titov ◽  
M. A. Novikov ◽  
V. A. Vokina ◽  
V. S. Rukavishnikov
Keyword(s):  
Nervous Tissue ◽  
Chemical Elements ◽  
Biological Effects ◽  
Experimental Studies ◽  
Biological Response ◽  
Immunohistochemical Method ◽  
Ether Anesthesia ◽  
Compensatory Response ◽  
White Rats ◽  
Liver And Kidney

Introduction. In recent years, magnetic nanoparticles, which can simultaneously have a therapeutic effect on the pathological focus, are used to magnify contrast enhancement and increase diagnostic sensitivity during magnetic resonance therapy (MRT). The last is carried out by the effective capture of neutrons, which among all the chemical elements is most pronounced in gadolinium. The use of gadolinium nanoparticles encapsulated in a polymeric matrix allows increasing the bioavailability of nanoparticles, reduces the possible toxicity of drugs. Aim. Evaluation of impact of new nanocomposite magnetically active metal complex gadolinium system on the morphofunctional state of the nervous tissue, liver, and kidney of rats. Material and methods. Experimental studies of biological effects of gadolinium-arabinogalactan nanocomposite (Gd-AG) were carried out on rats that were injected intraperitoneally for 10 days at the dose of 500 μg/kg in 0.5 ml of saline. Animals were sacrificed by decapitation under light ether anesthesia the next day after the end of exposure. To perform pathological studies, frontal sections of the temporal-parietal zone of the sensorimotor cortex, liver and kidney tissues were stained on ordinary histological glass slides with hematoxylin and eosin for viewing microscopic picture. The immunohistochemical method was used to determine the activity of the bcl-2, caspase-3 and hsp70 modulatory protein in apoptosis of white rats in brain neurons and to study the biological response of the organism at the subcellular level. Results. Histological analysis of tissues revealed a pronounced compensatory response of liver, a violation of the functional activity of kidneys. A decrease in the total number of normal neurons per unit area in brain tissue and an increase in the number of acts of neuronophagy indicate the initial stage of neurodegenerative process. Evaluation of the intracellular metabolism of neurons has not established the presence of signs characteristic of apoptotic process. Conclusion. The subacute effect of Gd-AG in a dose of 500 µg/kg causes a disturbance of morphofunctional state of liver, kidneys and nervous tissue, as well as modulation of cellular proteomics.

Comparative kinetic study of mechanical activation process of mica and talc for industrial application

2014 ◽  
Vol 59 ◽  
pp. 181-190 ◽  
Author(s):  
Ljubiša Andrić ◽  
Anja Terzić ◽  
Zagorka Aćimović-Pavlović ◽  
Ljubica Pavlović ◽  
Milan Petrov
Keyword(s):  
Kinetic Study ◽  
Mechanical Activation ◽  
Industrial Application ◽  
Activation Process

STALE GOLD-BEARING TAILINGS OF THE BALEIZOLOTO PLANT AND THE PROBLEM OF THEIR DISPOSAL

2021 ◽  
Vol 27 (4) ◽  
pp. 45-54
Author(s):  
G. Yurgenson ◽  
◽  
L. Shumilova ◽  
А. Khatkova ◽  
◽  
...  
Keyword(s):  
Negative Impact ◽  
Chemical Elements ◽  
Raw Materials ◽  
Precious Metals ◽  
Gold Content ◽  
Residential Areas ◽  
Extraction Technology ◽  
Useful Components ◽  
Technogenic Raw Materials ◽  
Gold Bearing

The relevance of the research is the need to recultivate the waste from the enrichment of gold-bearing ores that lie in the immediate vicinity of the residential areas of Baley city, which have a negative impact on the environmental situation in it, as well as to develop a technological approach to the extraction of gold and silver. The purpose of the study is to study the material composition and develop a technology for extracting precious metals. The object of the study is the stale tailings of the ZIF-1 plant “Baleizoloto”. The subject of the study is mineral composition of stale tailings, content of useful components and their extraction technology, the method and methodology presented by mineralogical and chemical analyses of enrichment tailings. Results. The analysis of the tailings dumps’ state of the gold recovery factories of the Baleizoloto plant was carried out. The contents of gold and other chemical elements, among which arsenic, zinc, copper, antimony, and lead predominate, were determined. The gold content prevails in the stale tailings of the ZIF-1 factory, which processed the ores of the Baley deposit, and is in the range of 1.09-1.37 g / t, on average – 1.17 g/t. This determines the prospects for their primary processing. The gold in the clay-sand fraction of the stale tailings is mainly found in thin accretions with quartz, carbonates, pyrite, arsenopyrite, sulfosols, and tellurides. The field of application is processing of technogenic raw materials. Conclusions. It was determined that the sizes of gold inclusions are in the range of 0.7-0.03 mm, the gold penetration varies from 63 to 91.15, and on average is 82.13; the main impurity in gold is silver with a content of 8.85-37%; the average silver content in the tailings of the ZIF-1 factory is 1.85 g/t; the recommended technological scheme for processing stale tailings of ZIF-1 of the Baleizoloto plant has been developed, including the following operations: photoelectron-activation preparation, pelletizing with active solution, heap leaching, two-stage sorption with bubbling with ozone

Effect of mechanical activation on the structure of pulverized coal and iron ore powder

2019 ◽  
Vol 116 (6) ◽  
pp. 624
Author(s):  
Rufei Wei ◽  
Dongwen Xiang ◽  
Hongming Long ◽  
Jiaxin Li ◽  
Qingmin Meng
Keyword(s):  
Free Energy ◽  
Mechanical Activation ◽  
Gibbs Free Energy ◽  
Iron Ore ◽  
Pulverized Coal ◽  
Activation Process ◽  
Free Energies ◽  
Boundary Area ◽  
Particle Sizer ◽  
Storage Energy

Morphologies and structures of pulverized coal and iron ore powder after mechanical activation were studied by SEM, XRD, FTIR and laser particle sizer. The microcrystalline structure of coal was found to be destroyed by mechanical activation via reducing the pile height and number of layers, and the organic structure of coal was altered through the destruction of the ether bond. Mechanical activation led to distortions and dislocations of the crystal lattice of iron ore, decreasing crystallite size, increasing the grain boundary area, and producing an amorphous phase. These increased the Gibbs free energies of dislocations and grain boundaries as well as the surface Gibbs free energy and the amorphization Gibbs free energy, which would eventually increase the energy stored in iron ore called mechanical storage energy. The longer the mechanical activation process, the higher mechanical storage energy for the iron ore will be saved. The amorphization Gibbs free energy is the biggest among the four kinds of Gibbs free energy, accounting for 94.8% ∼ 87.1% of the total storage energy in the mechanical activated iron ore.

scholarly journals THE ACTIVATION OF PROTHROMBIN, WITH SPECIAL REFERENCE TO "THROMBOPLASTIC ENZYME" (TRYPTASE)

Blood ◽  
1948 ◽  
Vol 3 (10) ◽  
pp. 1130-1160 ◽  
Author(s):  
JOHN H. FERGUSON ◽  
BURTON L. TRAVIS ◽  
EARL B. GERHEIM
Keyword(s):  
Activation Process ◽  
Cent Solution ◽  
High Potency ◽  
Trace Impurities ◽  
Accessory Factor ◽  
Ca Ions ◽  
Special Circumstances ◽  
Tissue Origin ◽  
Rate Of Activation ◽  
Thrombin Formation

Abstract A number of high-potency purified prothrombin preparations,61 in 0.2-0.5 per cent solution in borate buffer (pH = 7.7), maintain for days or weeks a stable thrombin-forming ability, whether (a) with buffer alone, (b) with brain thromboplastin suspension, (c) with CaCl2. Nevertheless, they all contain a trace of thrombin and continue to activate "spontaneously" at a very slow rate. Optimal addition of Ca-salt somewhat accelerates this and usually leads to maximal (complete) thrombin formation in 2-11 days at room temperature. Except in a few cases, where ionized Ca++ is demonstrable, thromboplastin, alone, is without effect, but added with calcium, it completes the activation in a matter of minutes or hours depending principally upon the concentration used. Experimental analysis of the activation process stresses the participation of (1) Ca-ions, (2) thromboplastic P-lipid factor (cephalin), (3) plasma and tissue tryptase (proteolytic enzyme). Each of these factors is studied in detail with reference to mode of action, optimal concentration, side-effects, and relation to inhibitors. Inhibition of prothrombin activation may be considered under the following heads: (1) "decalcifying" agents (e.g., oxalates, citrates, etc.), which (a) depress Ca-ionization and thus prevent thrombin formation, and (b), under special circumstances, reverse the process of activation; (2) "antithromboplastic" (? anticephalin) agents, (e.g., heparin, and probably soybean trypsin-inhibitor, to some extent); (3) "antitryptase" agents (e.g., crystalline trypsin-inhibitors from pancreas and soybean), which inhibit the thromboplastic enzyme (accessory factor). Excess Ca++ slows rate of thrombin formation. The evidence suggests that thrombin formation proceeds via an "intermediary" calcium-prothrombin-cephalin (thromboplastic phosphatide) complex or compound. The amounts of (a) thromboplastic P-lipid (cephalin or "thromboplastin") and (b) Ca++ determine both the rate of activation and the final thrombin yield. However, the ultimate ("ripe") thrombin owes none of its activity to the presence of any calcium or phospholipid. The three types of activator (Ca, thromboplastin, and thromboplastic enzyme) occur as "trace impurities" in prothrombin preparations, but Seegers’ most purified materials are tryptase-free. Tryptase (and trypsin) are "thromboplastic" only in the presence of adequate calcium and phospholipid factors, which may, however, be "mobilized" from protein combination, including prothrombin. In this way the two basic activators are, in a sense, "catalyzed" in their prothrombin-activating reactions. The significance of proteolytic actions (fibrinolysis, fibrinogenolysis, prothrombinolysis, and sometimes thrombinolysis) by natural tryptase of plasma and tissue origin is investigated and discussed in relation to the broader aspects of the blood-coagulation problem.

Influence of Particle Size Distribution, Energy Condition and Reactivity of the Deposited Material on Nanopatterning of Surface Layers Made of Shape Memory Materials

2017 ◽  
Vol 730 ◽  
pp. 8-14 ◽  
Author(s):  
Zhesfina Michailovna Blednova ◽  
Peter Olegovich Rusinov ◽  
Maria Evgenievna Bezmogorychnaya
Keyword(s):  
Shape Memory ◽  
Mechanical Activation ◽  
Energy Intensity ◽  
Energy Condition ◽  
Thermodynamic Characteristics ◽  
Basic Material ◽  
Activation Process ◽  
Surface Layers ◽  
Study Results ◽  
Shape Memory Materials

The article contains a block diagram of the mechanical activation process of multicomponent shape memory materials, taking into account the variety of influencing factors. We proposed to evaluate the reactivity of the deposited material by using the energy criterion (energy intensity), determined by additivity concept as an amount of the basic material energy and energy accumulated during mechanical activation. The energy intensity of the basic material depends on the chemical and phase composition and is determined by the thermodynamic characteristics and is based on diagrams of the systems. The energy accumulated during the MA, is determined on the basis of X-ray structural analysis. We have shown experimentally that increase in fineness of grind leads to growth in the number of active centers. This enables nanopatterning of surface layers in high-velocity oxygen-fuel spraying (HVOF). Increasing the time of MA (1.5 h) promotes a more homogeneous structure during HVOF. The study results allow developing practical recommendations for effective implementation of multi-component SME materials with HVOF.

scholarly journals Research into special technological effects for formation of wear resistant coatings using mineral raw materials of the far eastern region

2018 ◽  
Vol 56 ◽  
pp. 03027
Author(s):  
Viktor Makienko ◽  
Igor Romanov ◽  
Pavel Sokolov ◽  
Alexander Atenyaev ◽  
Dmitry Pervakov
Keyword(s):  
Mechanical Properties ◽  
Raw Materials ◽  
Experimental Studies ◽  
Eastern Region ◽  
Mineral Raw Materials ◽  
Wear Resistant Coatings ◽  
Thermal Fields ◽  
Additional Influence ◽  
Far Eastern

The results of the study of the possibility of using additional technological influence in the formation of doped coatings are presented. The distribution of thermal fields has been calculated, which makes it possible to estimate and predict the influence of additional influence on the formation of the coating in a simplified manner. Experimental studies have shown that additional technological influence promotes mixing of the melt, leading to an increase in the transition of alloying elements, as well as an increase in the mechanical properties and quality of the weld metal.

Determination of Trace Impurities in Alkali Metals

1980 ◽  
Vol 74 (5-6) ◽  
pp. 423-433 ◽  
Author(s):  
I. Schreinlechner ◽  
P. Sattler ◽  
J. Kozuh
Keyword(s):  
Alkali Metals ◽  
Trace Impurities

Recycling Lithium-containing Compounds from Spent Current Sources

2019 ◽  
Vol 23 (5) ◽  
pp. 10-15 ◽  
Author(s):  
A.M. Gonopolsky ◽  
D.A. Makarenkov ◽  
V.I. Nazarov ◽  
M.I. Klyushenkova ◽  
A.P. Popov
Keyword(s):  
Mechanical Activation ◽  
Reverse Osmosis ◽  
Pilot Plant ◽  
Experimental Studies ◽  
Lithium Ion ◽  
Ion Current ◽  
Ball Mills

The work is devoted to the development of an assessment of existing methods of utilization of lithium chemical current sources. Modern types of lithium-ion current sources are analyzed. It is shown that the cathode and electrolyte materials are most valuable for the process of separating commercial lithium. A modern technological disposal scheme is proposed, where mechanical activation processes are used using ball mills and baromembrane technologies (ultrafiltration and reverse osmosis). The results of experimental studies on the pilot plant.

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