scholarly journals Technogenic Zinc Usage Possibilities Investigation for Gold Cementation

2017 ◽  
Vol 2 (2) ◽  
pp. 28
Author(s):  
Naumov K.D. ◽  
Lobanov V.G. ◽  
Zelyah Y.D. ◽  
Yakornov S.A. ◽  
Skopin D.Y.
Keyword(s):  
Zinc Content ◽  
Zinc Powder ◽  
Alkaline Solutions ◽  
Technological Properties ◽  
Hydrometallurgical Processing ◽  
Ferrous Metals ◽  
High Zinc ◽  
Zinc Powders ◽  
Cyanide Solutions

<p>Industrial dusts with high zinc content are formed in nonferrous and ferrous metals metallurgy. Hydrometallurgical processing of such dusts can be used. In this case, alkaline solutions with high impurities content are formed. It is possible to produce zinc powder with different technological properties by electroextraction from mentioned alkaline solutions. This work describes investigation of zinc powders usage possibilities to gold cementation from cyanide solutions.</p>

Gold Cementation by Dendritic Zinc Powders in Percolation Mode

2020 ◽  
Vol 989 ◽  
pp. 543-547
Author(s):  
K.D. Naumov ◽  
Vladimir G. Lobanov
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Alkaline Solutions ◽  
Wide Range ◽  
Zinc Powders ◽  
Cyanide Solutions

In present article gold cementation features from cyanide solutions using dendritic zinc powders are studied. The powders were obtained by electroextraction from alkaline solutions. Powders with different physical properties were obtained by means of change in current density (from 0.5 to 2 A/m2) and NaOH concentration in solution (from 100 to 400 g/dm3) at the constant zinc concentration (10 g/dm3). The physical properties of mentioned powders were studied using SEM (Jeol JSM-6390LA), BET (Gemini VII 2390) and laser diffraction (Sympatec HELOS & RODOS). It is shown that electrolytic powders have high specific surface area, which is 1.8–2.6 times larger than the surface area of ​​the zinc powder currently used for cementation. At that electrolytic powders particle size is 8-22 times larger than the particle size of powder currently used for cementation. The reason of high specific surface area is the electrolytic zinc powders dendritic structure. It was found that the obtained powders precipitate gold from cyanide solutions with a greater efficiency in a wide range of productivity. Laboratory unit simulating Merrill-Crow technology was used for cementation. Immediately ahead conducting the experiments, Na2SO3 was added to the solution in excess to remove dissolved oxygen. Zinc powders were plated by dendritic lead before loading into the laboratory setup by cementation. Lead was added as acetate (Pb (CH3COO)2). The consumption of lead acetate was 10% by weight of zinc. Correlation between the powders physical properties and the gold extraction is shown.

scholarly journals Features of gold cementation in percolation mode by electrolytic zinc powders

2020 ◽  
pp. 19-26
Author(s):  
K. D. Naumov ◽  
V. G. Lobanov
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fine Powder ◽  
Zinc Powder ◽  
Gold Deposition ◽  
Electrolytic Zinc ◽  
Zinc Powders ◽  
Cyanide Solutions

The study covers physicochemical features of dendritic zinc powders and their effect on gold cementation from cyanide solutions. Three zinc powders were obtained in a laboratory environment by electroextraction at different conditions, and these powders featured various particle size and specific surface area. The properties of zinc powders obtained and powder currently used for gold cementation were evaluated using SEM (Jeol JSM-6390LA), BET (Gemini VII 2390) and laser diffraction (Sympatec HELOS & RODOS) methods. It is shown that electrolytic powders have high specific surface area (1.3–2.6 times more) and a low bulk density (3.1–3.8 times less), relative to zinc powder currently used for gold cementation. It was found that due to specific physical properties electrolytic powders have low hydraulic resistance, which eliminates the need for inert additives introduced during cementation, increases unit capacity and reduces the load on equipment. Inert additives elimination will additionally increase the gold content in the resulting product. The dendritic morfology of zinc powders obtained compensates high particle size resulting in the high efficiency of gold precipitation. At the long cementation cycle the effective gold deposition area (with gold extraction of more than 97 %) turned out to be shorter for electrolytic powder compared to fine powder currently used. However, in practice, the cementation cycle is always limited by fine powder throughput and it is not possible to achieve the full zinc potential. The resulting cementation product usually contains 25–35 % of unused zinc. These studies show the effectiveness of using electrolytic zinc powder for gold cementation from cyanide solutions.

scholarly journals Evaluation of Recombinant Inbred Lines for Higher Iron and Zinc Content Along with Yield and Quality Parameters in Rice (Oryza sativa L.)

2020 ◽  
Author(s):  
Maini Bhattacharjee ◽  
Kasturi Majumder ◽  
Sabyasachi Kundagrami ◽  
Tapash Dasgupta
Keyword(s):  
Iron Content ◽  
Oryza Sativa L ◽  
Recombinant Inbred Lines ◽  
Zinc Content ◽  
Correlation Study ◽  
Inbred Lines ◽  
Quality Parameters ◽  
Fe Content ◽  
High Zinc ◽  
Iron And Zinc

Rice is one of the most important staple food crops for billions of people throughout the world. It is the cheapest source of dietary energy, protein and minerals for people but poor in micronutrients such as Fe and Zn to eliminate “hidden hunger”. In the present study, a population of 126recombinant inbred lines developed from a cross between Lemont X Satabdi (IET 4786) were used to identify high iron and zinc content coupled with yield and yield attributing traits. Analysis of Variance revealed that a considerable variation in iron and zinc existed among genotypes. The correlation study revealed that number of filled grain was positively associated with panicle length and yield per plant and number of panicles, but no significant positive correlation was observed between grain zinc content and iron content. Zinc and iron content of rice was estimated using Atomic Absorption Spectrophotometer and the samples were prepared by tri-acid digestion method. Among RIL lines, the line 57, 97,120, 48, 99, 124 contained more than 30 ppm Fe and the lines 24, 6, 9, 23, 29, 125 were found to possess more than 50 ppm Zn. The lines 9,6,48 and 57 were recorded to be high yielding with high zinc and Fe content in grain and in future these four lines look promising for multi location trial also. These high Fe and Zn content genotypes can be utilized in future breeding programme as a donor or good source for bio fortification of rice genotypes.

Use of Electrolytic Zinc Powder for Cementation of Gold from Cyanide Solutions

Metallurgist ◽  
2018 ◽  
Vol 62 (5-6) ◽  
pp. 456-463 ◽  
Author(s):  
S. A. Yakornov ◽  
K. D. Naumov ◽  
V. G. Lobanov ◽  
P. A. Kozlov ◽  
Ya. D. Zelyakh ◽  
...  
Keyword(s):  
Zinc Powder ◽  
Electrolytic Zinc ◽  
Cyanide Solutions

Understanding the behaviour of zinc and impurities during alkaline leaching of zinc bearing product obtained as a result of pyrometallurgical processing of ferrous metallurgy dusts and examining the phase composition of leaching residue

2021 ◽  
pp. 52-58
Author(s):  
P. A. Kozlov ◽  
A. M. Panshin ◽  
S. A. Yakornov ◽  
D. A. Ivakin
Keyword(s):  
Phase Composition ◽  
Alkaline Medium ◽  
Selective Dissolution ◽  
Cement Industry ◽  
Alkaline Solutions ◽  
Iron Compounds ◽  
Pyrometallurgical Process ◽  
Hydrometallurgical Processing ◽  
Hydroxo Complexes ◽  
Leaching Residue

This paper describes a technique developed for processing EAF dusts and recovering zinc. The technique is based on the Waelz process without zinc sublimation and allows to obtain a product suitable for hydrometallurgical processing and clear of lead or halogens in one process stage. It would be feasible to use an alkaline hydrometallurgical process for this product as it enables a selective recovery of zinc while iron remains in the solid residue. A pyrometallurgical process is necessary to remove halogens, increase the solubility of zinc and remove lead. In the alkaline process, the latter transfers to the solution together with zinc. As part of the development procedure, the thermodynamics of lead and iron in alkaline medium was studied. For this, equilibrium diagrams were built in the Eh – рН coordinates. Findings: – zinc can dissolve at рН > 12.7 while forming the following anions: ZnO22– and [Zn(OH)n]2–n. A study that looked at leaching zinc ores confirms that anions of the latter type do form; – lead can dissolve while forming [Pb(ОН)6]2–-type hydroxo complexes at рН > 12.5. When the solution is heated to 80 oС, their solubility can reach 140 g/dm3. In a hot solution hydroxo complexes form orthoplumbite and orthoplumbate ions PbО22–, PbО32– as a result of dehydration; – the low solubility of all iron compounds in alkaline medium and their position in the diagram only defined by the pH range suggest that the leach solutions contain no iron ions of any type. With the temperature raised to 80 oС, the equilibria in the Fe – H2O system remains unchanged in alkaline medium and no significant increase in the solubility of iron compounds is observed. The findings show that selective dissolution of products containing zinc oxides (including EAF dusts after the above mentioned pyrometallurgical process) in alkaline solutions is feasible. The zinc leaching residue was analyzed for chemical and phase composition to find possible applications for it. It is demonstrated that calcium ferrites, aluminates and alumosilicates account for 80% of the residue. This iron-calcium material can be utilized by cement industry.

scholarly journals Durability of vitreous enamel coatings and their resistance to abrasion, chemicals, and corrosion: a review

2020 ◽  
Author(s):  
Stefano Rossi ◽  
Francesca Russo ◽  
Massimo Calovi
Keyword(s):  
Alkaline Solutions ◽  
Future Research ◽  
Barrier Effect ◽  
Technological Properties ◽  
Good Resistance ◽  
Vitreous Enamel ◽  
Good Product ◽  
Production Technologies ◽  
Product Protection ◽  
Protection Property

Abstract Vitreous enamels represent a class of coatings with different technological properties, mainly appreciated for the protection they guarantee to the covered substrates. This review introduces enamel coatings, describing their production technologies and presenting the main properties affecting the enamel’s durability. Firstly, this review article introduces the most important studies regarding the improvement in abrasion resistance, highlighting both successes and failures. Afterward, the work reveals an outlook about the resistance to chemicals, underlining the good resistance of enamels toward acidic chemicals and discussing the results of studies aimed to improve their performances toward alkaline solutions. This review also considers the corrosion protection property of enamels, highlighting the high barrier effect they provide against the absorption of aggressive substances toward metal substrates. Finally, new perspectives and possible future research paths are presented, being aware that this kind of coating offers both good product protection and functional integrity over time.

Effect of ZnO on Thermo Physical and Structural Properties of Lithium Zinc Silicate Glass-Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 947-952 ◽  
Author(s):  
Govind P. Kothiyal ◽  
B.I. Sharma ◽  
V.K. Shrikhande ◽  
Madhumita Goswami ◽  
J.V. Yakhmi
Keyword(s):  
Glass Matrix ◽  
Glass Ceramics ◽  
Zinc Content ◽  
Zinc Silicate ◽  
Remarkable Difference ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Zinc ◽  
Controlled Nucleation ◽  
Thermo Physical Properties

Lithium zinc silicate (LZS) glass-ceramics with compositions: (a) Li2O-ZnO-SiO2-Na2OB2O3- P2O5 and (b) Li2O-ZnO-SiO2-K2O-Al2O3-B2O3-P2O5 have been prepared by controlled nucleation and crystallization. The effect of ZnO/(ZnO+SiO2) ratio on various thermo-physical properties was investigated by changing the ratio from 0.1 to 0.31 in the case of (a). Different crystalline phases have been identified by X-ray diffraction studies in glass-ceramics including cristobalite, Li3Zn0.5SiO4 and Li2SiO3. Density ( r) was found to increase from 2.62 to 2.82 gm cm-3 while microhardness (VHN) decreased from 6.56 to 5.79 GPa with increase in ZnO/(ZnO+SiO2) ratio in the glass-ceramics. Average thermal expansion coefficient (TEC) in the temperature range 30 to 450oC increased from 125x10-7 to 185x10-7 /oC. The increase in TEC and decrease in microhardness are thought to be due to the formation of different phases, which in turn influence the rigidity/bonding in the glass-ceramics. A remarkable difference in the microstructure close to interface of the glass-ceramics to Cu seal was seen in both the cases [high ZnO content (a) of ZnO/(ZnO+SiO2) ratio 0.31 and low ZnO content (b) of ZnO/(ZnO+SiO2) ratio 0.024]. Both the microstructures showed globally two contrast phases of bright and dark dispersed in the glass matrix. An interesting dandritic phase observed towards core in the microstructure for the high zinc content is not seen in the microstructure for low zinc content glass-ceramic. The seal withstands a vacuum of ~ 10-6 torr at helium leak rate of 3x10-10 torr litre/sec.

scholarly journals Monoclonal antibodies to a zinc-binding protein of rat Paneth cells.

1994 ◽  
Vol 42 (4) ◽  
pp. 467-472 ◽  
Author(s):  
M Sawada ◽  
Y Horiguchi ◽  
P Abujiang ◽  
N Miyake ◽  
Y Kitamura ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Mononuclear Cells ◽  
Binding Protein ◽  
Paneth Cell ◽  
Zinc Content ◽  
Paneth Cells ◽  
Zinc Binding ◽  
Positive Staining ◽  
High Zinc ◽  
And Function

Paneth cells are morphologically well characterized but their function has been not elucidated. Previously, we identified and purified a 90 KD zinc-binding protein (ZBPP-1) in rat intestine that was localized to Paneth cell granules, consistent with their high zinc content. To further elucidate the structure and function of ZBPP-1, we immunized Balb/c mice with purified ZBPP-1 and identified four independent monoclonal antibodies (MAb) producing MAb ZIP-1 (IgM), ZIP-2 (IgG1), ZIP-3 (IgM), and ZIP-4 (IgM). Immunohistochemistry (IHC) and immunoelectron microscopy (IEM) with these MAb showed positive staining of Paneth cell cytoplasmic granules. MAb ZBPP-1 also stained a population of mononuclear cells in the lamina propria of digestive tract mucosa and a few cells in spleen, presumably a subset of macrophages. These MAb will provide a useful tool to study the function of Paneth cells in human health and disease, since they cross-reacted with human intestinal Paneth cells and mucosal mononuclear cells.

The effect of cyanide and lead ions on the cementation rate, stoichiometry and morphology of silver in cementation from cyanide solutions with zinc powder

2005 ◽  
Vol 76 (3-4) ◽  
pp. 193-205 ◽  
Author(s):  
G. Viramontes Gamboa ◽  
M. Medina Noyola ◽  
A. López Valdivieso
Keyword(s):  
Zinc Powder ◽  
Lead Ions ◽  
Cyanide Solutions
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