Silver-Containing Concentrate Processing

2020 ◽  
Vol 989 ◽  
pp. 456-460
Author(s):  
A. V. Nikanorov
Keyword(s):  
Precious Metals ◽  
Reverberatory Furnace ◽  
High Grade ◽  
Technological Operation ◽  
Silver Recovery ◽  
Flotation Concentrate

The goal of the research was to melt the silver-containing concentrate from the Dukatsk deposit (Magadansk region) in a reverberatory furnace. Preparatory research has established that internal collector smelting is an effective way to recover precious metals from the flotation concentrate of the Dukatsk deposit. This method is based on the property of lead and copper in the concentrate in an amount comparable to that of silver, to collect precious metals in a metal or matte phase in the process of segregation smelting. Recovery of silver in a high-grade alloy in one technological operation corresponds to the planned performance (silver recovery into an alloy of 93.0%) in processing flotation concentrates at non-ferrous industry plants.

scholarly journals Gold recovery from flotation concentrate from gold mine tailings using dissolve smelting

2019 ◽  
Vol 55 (3) ◽  
pp. 343-349
Author(s):  
U. Erdenebold ◽  
C.-M. Sung ◽  
J.-P. Wang
Keyword(s):  
Molten Slag ◽  
Precious Metals ◽  
Copper Slag ◽  
Molten Copper ◽  
Flotation Concentrate ◽  
Sulphide Minerals ◽  
Oxidative Roasting ◽  
Valuable Metals ◽  
Gold Mine Tailings ◽  
High Concentrations

Gold flotation concentrate may contain relatively high concentrations of valuable metals such as iron, copper, and zinc, and occasionally, even precious metals such as gold. The major components of the concentrate are SiO2, Fe2O3, and Al2O3, but it also contains reactive sulphide minerals such as pyrite. The sulphides in the flotation concentrate are fully converted into an oxide form during oxidative roasting, therefore, the chemical composition of the roasted concentrate is considered to be a copper slag. High temperature smelting with additives to dissolve Au from the gold concentrate into a molten copper was used in the research. Gold greatly dissolved at 1600?? under a CaO/SiO2 ratio of 1.25, suggesting the increase in the dissolution of gold into molten copper with decreasing viscosity of the molten slag-like concentrate at high temperatures.

scholarly journals Electrochemical Recovery of Silver Using a Simple Cell

2021 ◽  
Vol 29 (48) ◽  
pp. 158-166
Author(s):  
Igor Wachter ◽  
Tomáš Štefko
Keyword(s):  
Heavy Metal Contamination ◽  
Rapid Development ◽  
Waste Product ◽  
Precious Metals ◽  
Industrial Applications ◽  
Electrical Circuit ◽  
Circuit Breakers ◽  
Silver Recovery ◽  
Final Yield ◽  
User Friendly

Abstract The amount of generated e-waste during the last decades has been steadily raising to the point at which it is highly desirable to obtain the precious metals by recycling the e-waste without the need of exploiting the environment. The rapid development of technology, steep growth of modern facilities with user-friendly electronical devices and a stiff competition between manufacturers are among the main reasons for decreasing the life span of such devices, and subsequently end up as an obsolete waste product. Rapid industrialization and urbanization have also caused many environmental problems, e.g. heavy metal contamination. Silver is one of the precious metals with exceptionally high industrial applications, which makes it an area of research of high interest. Demand for silver continues to grow with progress in the industrialized world, while the world reserves of high-quality silver ores are declining. Although, there are large stocks of low and lean quality silver ores still to be mined, the main goal of this article is to provide a simple, effective and eco-friendly method of silver recovery from e-waste, e.g. electrical circuit breakers using an electrochemical cell. After 20.75 days of the experiment, 1481.5 grams of silver contacts were processed with a final yield of 61.41 % grams of silver dendrite crystals (99.9 % purity).

Textural Characteristics of Barren and Mineralized Colloform Quartz Bands at the Low-Sulfidation Epithermal Deposits of the Omu Camp in Hokkaido, Japan: Implications for Processes Resulting in Bonanza-Grade Precious Metal Enrichment

2020 ◽  
Author(s):  
Lauren R. Zeeck ◽  
Thomas Monecke ◽  
T. James Reynolds ◽  
Erik R. Tharalson ◽  
Katharina Pfaff ◽  
...  
Keyword(s):  
Precious Metal ◽  
Precious Metals ◽  
High Grade ◽  
Metal Enrichment ◽  
Near Surface ◽  
Epithermal Deposits ◽  
Fine Grained ◽  
Precursor Phase ◽  
Ore Minerals ◽  
Low Sulfidation

Abstract The Miocene low-sulfidation epithermal deposits of the Omu camp in northeastern Hokkaido, Japan, are small past-producers of precious metals and represent significant exploration targets for high-grade Au and Ag ores. The quartz textures of ore samples and the distribution of ore minerals within quartz veins were studied to identify the processes that resulted in the bonanza-grade precious metal enrichment in these deposits. In the high-grade vein samples, which are crustiform or brecciated in hand specimen, ore minerals exclusively occur within colloform quartz bands. High-magnification microscopy reveals that ore-bearing colloform bands consist of fine-grained quartz exhibiting relic microsphere textures and quartz having a mosaic texture that formed through recrystallization of the microspheres. The presence of relic microspheres is evidence that the microcrystalline quartz hosting the ore minerals formed through recrystallization of a noncrystalline silica precursor phase. The ore-hosting colloform bands composed of agglomerated microspheres alternate with barren colloform quartz bands that are composed of fibrous chalcedonic quartz and mosaic quartz formed through recrystallization of the chalcedony. The findings of this study are consistent with previous models linking bonanza-grade precious metal enrichment and the formation of bands of noncrystalline silica in low-sulfidation epithermal veins to episodic vigorous boiling or flashing of the hydrothermal system in the near-surface environment.

Biooxidation and Cyanidation for Gold and Silver Recovery from Acid Mine Drainage Generating Tailings (Ticapampa, Peru)

2007 ◽  
Vol 20-21 ◽  
pp. 91-94 ◽  
Author(s):  
Adrian A. Nagy ◽  
Eberhard D. Gock ◽  
Frank Melcher ◽  
Terzan Atmaca ◽  
Lothar Hahn ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Precious Metals ◽  
Acidithiobacillus Thiooxidans ◽  
Silver Recovery ◽  
Acid Mine ◽  
Tailings Remediation ◽  
Refractory Gold ◽  
Shake Flasks ◽  
Sulfide Concentrate

The acid mine drainage (AMD) generating sulfidic tailings have a total mass of 1,639,130 t containing 1.65 g/t Au, 34.5 g/t Ag, 7.74 % Fe, 5.91 % S, 3.2 % As, 0.75 % Zn and 0.05 % Cu. The precious metals Au and Ag are enriched in the fine fractions. Approximately 35 % of the material is below 25 /m in size and 53 % below 63 /m. Electron microprobe analysis of a sulfide concentrate of the tailings, produced by gravity separation, proved the occurrence of pyrite and arsenopyrite with appreciable sphalerite and galena. Refractory gold (up to 316 g/t) is hosted in Asrich zones of some arsenopyrites. Approximately 200 g of the sulfide concentrate of the tailings was biooxidized in laboratory shake flasks using an adapted mixed culture of Acidithiobacillus ferrooxidans (Ram 6F), Acidithiobacillus thiooxidans (Ram 8T) and Leptospirillum ferrooxidans (R3). During biooxidation, arsenopyrite was preferentially dissolved and the secondary mineral tooeleite (Fe8(AsO4)6(OH)5·H2O) precipitated. The following cyanidation of the biooxidized sulfide concentrate showed a recovery of 97 % and 50 % for Au and Ag, respectively. The values were 56 % and 18 % for the untreated concentrate. The recovery of Au and Ag from the tailings significantly reduces the costs for the tailings remediation to mitigate AMD release.

scholarly journals The Distribution of Precious Metals in High-Grade Banded Quartz Veins from Low-Sulfidation Epithermal Deposits: Constraints from µXRF Mapping

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 740 ◽  
Author(s):  
Erik Tharalson ◽  
Thomas Monecke ◽  
T. Reynolds ◽  
Lauren Zeeck ◽  
Katharina Pfaff ◽  
...  
Keyword(s):  
Precious Metals ◽  
Thermal Waters ◽  
High Grade ◽  
Epithermal Deposits ◽  
Quartz Veins ◽  
Ore Minerals ◽  
Low Sulfidation ◽  
Hand Specimen ◽  
Black Color ◽  
Representative Samples

High-grade ore zones in low-sulfidation epithermal deposits are commonly associated with the occurrence of banded quartz veins. The ore minerals in these veins are heterogeneously distributed and are mostly confined to ginguro bands, which can be identified in hand specimen based on their distinct dark gray to black color. Micro-X-ray fluorescence element maps obtained on representative samples of banded quartz veins show that Au occurs together with Ag minerals in some of the ginguro bands, but Au can also be present in quartz bands that are light gray to white and cannot be macroscopically distinguished from barren bands. The occurrence of compositionally distinct ginguro and gankin bands, the latter being a new term coined here for colloform quartz bands containing primarily electrum or native gold, can be explained by temporal changes in the composition of the ore-forming thermal waters or variations in the conditions of ore deposition. Textural relationships, including the dendritic shape of ore minerals that appear to have grown in a matrix of silica microspheres, suggest that the ginguro and gankin bands have formed as a result of rapid deposition associated with vigorous boiling or flashing of the thermal waters.

scholarly journals Post-kinematic diorite intrusions in Archaean basement rocks around outer Fiskefjord, southern West Greenland

1991 ◽  
Vol 39 ◽  
pp. 167-177
Author(s):  
A. A. Garde
Keyword(s):  
Trace Element ◽  
Final Stage ◽  
Precious Metals ◽  
Granulite Facies ◽  
High Grade ◽  
West Greenland ◽  
Mafic Intrusions ◽  
Basement Rocks ◽  
High Grade Metamorphism ◽  
Crust Deformation

About twenty small dioritic intrusions around outer Fiskefjord, southern West Greenland, which are undeformed and unmigmatised, mark the final stage in middle Archaean accretion of continental crust, deformation and high-grade metamorphism in the Akia terrane. The diorites were emplaced into hot tonalitic gneisses, some of which were thoroughly retrograded from granulite facies prior to diorite intrusion. The diorites are themselves sporadically retrograded. A conventional zircon U-Pb age of 3017 + 12/-10 Ma has been obtained from one of the diorites. The diorites have SiO2 contents between ea. 52 and 58 wt. % and up to ea. 15% MgO, and some of them border on leuconorite or anorthosite, with normative plagioclase contents up to ea. 85 wt. % . Trace element compositions are characterised by elevated amounts of Zn, Co, Ni, and especially Cr, but low contents of several LIL elements, and they were probably contaminated with sialic crust. The diorite intrusions may be related to a group of a more mafic intrusions with anomalous contents of precious metals, forming the "norite belt" some 50 km north of Fiskefjord.

1278: The Role of Diagnostic Criteria of Obstruction in Patients with High Grade Cystocele: Correlation to Subjective Symptoms

2007 ◽  
Vol 177 (4S) ◽  
pp. 421-421
Author(s):  
Veronica Triaca ◽  
Christian O. Twiss ◽  
Ramdev Konijeti ◽  
Larissa V. Rodriguez ◽  
Shlomo Raz
Keyword(s):  
Diagnostic Criteria ◽  
High Grade ◽  
Subjective Symptoms
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