Oxredmetry as a method to ensure optimum distribution of precious metals in pressure oxidation leaching of pyrrhotite material depending on the type of surfactant used

2019 ◽  
pp. 46-55
Author(s):  
M. N. Naftal ◽  
◽  
L. V. Antonenko ◽  
S. S. Naboychenko ◽  
N. S. Kuznetsov ◽  
...  
Keyword(s):  
Precious Metals ◽  
Optimum Distribution ◽  
Pressure Oxidation

scholarly journals Autoclave treatment of cakes after pressure oxidation leaching of chalcopyrite concentrates

2020 ◽  
pp. 13-18
Author(s):  
A. V. Kritskii ◽  
M. A. Tretyak ◽  
К. A. Karimov ◽  
S. S. Naboichenko
Keyword(s):  
Precious Metals ◽  
Source Material ◽  
Metal Extraction ◽  
The Urals ◽  
Pressure Oxidation ◽  
Promising Alternative ◽  
Autoclave Treatment ◽  
Conventional Technology ◽  
Copper Refining ◽  
Chalcopyrite Concentrate

The existing technologies for copper-porphyry ores enrichment, located in deposits in the Urals of Russia, allow the production of chalcopyrite concentrates of the following composition, %: 21.5 Cu, 24.5 Fe, 26.5 S, 0.4 Pb, 17.6 SiO2, 1.8 CaO, 2–6 Au (ppm), 20– 40 Ag (ppm). A conventional technology for processing such concentrates includes autogenous smelting, matte desulfurization and blister copper refining. Pressure oxidation leaching (POX) is considered the most promising alternative technology for chalcopyrite concentrate processing. The POX of concentrates originated from Mikheevskii GOK allow the production a cake of the following chemical composition, %: 56–65 Fe2O3, 25–30 SiO2, 2.7 Ca, 0.3–1.0 Cu, 2–7 S, 0.6–0.8 Pb, 4–12 Au (ppm), 40–80 Ag (ppm); mass loss was 37–45 %. A standard method of cake cyaniding provides satisfactory indicators of precious metal extraction, but it requires a cumbersome area to be arranged for their processing and offers no solution for residue disposal. In this regard, this paper investigates the method of subsequent cake processing using autoclave treatment (AT) for iron removal. The study shows how the following parameters affect the results of this process: t = 110÷210 °C, H2SO4 = 15÷60 g/dm3, τ = 45÷ ÷120 min. A statistic description of the AT operation is developed. Recommended AT conditions (t = 110 °C, H2SO4 = 60 g/dm3, τ = 60÷100 min) allow to obtain the POX cake yield reduced to 30–35 % of the source material with the following composition, %: 28–33 Fe2O3, 47–53 SiO2, 2–5 Ca, 0.6–2.0 Cu, 0.8–1.5 Pb, 2–8 S. At the same time, the content of precious metals in the cake reaches 12–16 Au (ppm) and 80–120 Ag (ppm). Options for using AT products are proposed.

A High Voltage Electron Microscopy Study of Sub-Oxide Formation in Vanadium

1971 ◽  
Vol 29 ◽  
pp. 212-213
Author(s):  
R. H. Geiss ◽  
R. L. Ladd ◽  
K. R. Lawless
Keyword(s):  
High Vacuum ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Ultra High Vacuum ◽  
Pure Oxygen ◽  
Pressure Oxidation ◽  
High Voltage Electron Microscopy ◽  
Oxidation Study ◽  
Voltage Electron ◽  
Good Agreement

Detailed electron microscope and diffraction studies of the sub-oxides of vanadium have been reported by Cambini and co-workers, and an oxidation study, possibly complicated by carbon and/or nitrogen, has been published by Edington and Smallman. The results reported by these different authors are not in good agreement. For this study, high purity polycrystalline vanadium samples were electrochemically thinned in a dual jet polisher using a solution of 20% H2SO4, 80% CH3OH, and then oxidized in an ion-pumped ultra-high vacuum reactor system using spectroscopically pure oxygen. Samples were oxidized at 350°C and 100μ oxygen pressure for periods of 30,60,90 and 160 minutes. Since our primary interest is in the mechanism of the low pressure oxidation process, the oxidized samples were cooled rapidly and not homogenized. The specimens were then examined in the HVEM at voltages up to 500 kV, the higher voltages being necessary to examine thick sections for which the oxidation behavior was more characteristic of the bulk.

Formation of defects in implanted hipox-structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1406-1407
Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan
Keyword(s):  
High Pressure ◽  
Cross Section ◽  
Semiconductor Devices ◽  
Silicon Substrates ◽  
Processing Conditions ◽  
Pressure Oxidation ◽  
Deep Trench ◽  
Local Oxidation ◽  
Trench Isolation ◽  
And Behavior

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.

Eco-Friendly Recycling Potential of Microwave Melting for the Recovery of Useful and Precious Metals from E-Waste

2018 ◽  
Vol 63 (2) ◽  
pp. 39-52
Author(s):  
Daniela Violeta Dumitrescu ◽  
◽  
Vasile Soare ◽  
Ionuţ Constantin ◽  
Marian Burada ◽  
...  
Keyword(s):  
Precious Metals ◽  
Recycling Potential

MAGNETO-LIQUID SEPARATORS FOR PROCESSING FINE-GRAINED ORES OF NON-FERROUS RARE AND PRECIOUS METALS

2017 ◽  
Vol 12 (30) ◽  
pp. 53-61
Author(s):  
A.A. Solodenko ◽  
◽  
A.B. Solodenko ◽  
S.I. Evdokimov ◽  
Yu.G. Klykov ◽  
...  
Keyword(s):  
Precious Metals ◽  
Fine Grained

The Determinants of Capital Adequacy Ratio: The Case of the Vietnamese Banking System in the Period 2011-2015

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Ngoc Anh Nguyen
Keyword(s):  
Banking System ◽  
Precious Metals ◽  
Capital Adequacy ◽  
The Other ◽  
Total Asset ◽  
Data Set ◽  
Hand Size ◽  
Net Interest Margin ◽  
Capital Adequacy Ratio ◽  
Positive Effect

The analysis of a data set of observation for Vietnamese banks in period from 2011 - 2015 shows how Capital Adequacy Ratio (CAR) is influenced by selected factors: asset of the bank SIZE, loans in total asset LOA, leverage LEV, net interest margin NIM, loans lost reserve LLR, Cash and Precious Metals in total asset LIQ. Results indicate based on data that NIM, LIQ have significant effect on CAR. On the other hand, SIZE and LEV do not appear to have significant effect on CAR. Variables NIM, LIQ have positive effect on CAR, while variables LLR and LOA are negatively related with CAR.

How to make Russia a prosperous industrial country (about the role of the oil production and refining complex)

2020 ◽  
pp. 22-28
Author(s):  
Yu. Kanataev
Keyword(s):  
Precious Metals ◽  
Oil Production ◽  
Industrial Country ◽  
Industrial Scale ◽  
Deep Processing ◽  
Domestic Technology ◽  
Petrochemical Complex ◽  
Russian Economy ◽  
Further Development

The author, head of the Association of science-intensive enterprises having great experience in exploration of oil, precious metals, etc. in Russia and abroad (Austria, China, Israel, Ethiopia), first implemented on an industrial scale deep processing of oil using domestic technology, discusses the problems of further development of the Russian economy through the prism of their solutions to the main industries — oil and petrochemical complex.

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