Gravity-flotation gold-bearing ore concentration

2021 ◽  
Vol 1 (1) ◽  
pp. 4-15
Author(s):  
P. K. Fedotov ◽  
A. E. Senchenko ◽  
K. V. Fedotov ◽  
A. E. Burdonov
Keyword(s):  
High Performance ◽  
Gold Recovery ◽  
Gold Content ◽  
Flotation Concentrate ◽  
Stage Scheme ◽  
Study Results ◽  
Ore Minerals ◽  
Concentrate Yield ◽  
Flotation Concentration ◽  
Gold Bearing

The paper focuses on the study of the gold-bearing ore dressability. According to technological research, the average gold content is 11.88 g/t. The silver content is insignificant – 2.43 g/t. Main ore minerals in the sample are pyrite and pyrrhotite. According to mineralogical and X-ray structural analysis, the average content of these minerals in the ore is about 6 % (in total). Main rock-forming minerals of the original ore are: quartz (60.1 %), quartz-chlorite-mica aggregates (3.8 %), carbonates (7.1 %). According to the study results, it was found that the gold recovery in the GRG test was 72.75 % with a total concentrate yield of 1.34 % and a content of 664.78 g/t. At the same time, the gold content in tailings was 3.29 g/t. A stage test showed that it is advisable to use a two-stage scheme for ore processing by gravity technology only. The first stage is in the grinding cycle with the 60–70 % ore size, and the second stage is with the final classifier overflow size of 90 % –0.071 mm. Centrifugal separation has high performance as a free gold recovery operation in the grinding cycle. A concentrate with a gold content of 2426 g/t was obtained with a yield of 0.31 % and a recovery of 63.74 %. The beneficiation of first stage tailings ground to 90 % –0.071 mm at the KC-CVD concentrator (modeling) made it possible to extract gold into a total gravity concentrate (KC-MD + KC-CVD) of 87.25 % with a concentrate yield of 22.63 %. The gold content in tailings was 1.97 g/t. The results of gravity and flotation concentration of the original ore indicate the feasibility of using a combined gravity-flotation technological scheme. In a closed experiment of the initial ore beneficiation according to the gravity-flotation scheme at a natural pH of the pulp (without adding acid), the following products were obtained: gravity concentrate with a gold content of 2426 g/t at a yield of 0.31 % and recovery of 64.06 %; flotation concentrate (after the II cleaning) with a gold content of 122 g/t at a yield of 2.90 % and recovery of 33.01 %; the total gold recovery in the gravity-flotation concentrate was 94.07 % with a yield of 3.21 % and an Au content of 345.87 g/t, the gold content in the flotation tailings was 0.72 g/t.

scholarly journals APPLICATION OF THE JET SCHEME AND FLOTATION MODE WITH A VAPOR-AIR MIXTURE DURING GOLD-BEARING ORES ENRICHMENT

2021 ◽  
Vol 13 (1) ◽  
pp. 84-93
Author(s):  
Sergey EVDOKIMOV ◽  
◽  
Tatyana GERASIMENKO ◽  
Azamat MARZOEV ◽  
◽  
...  
Keyword(s):  
Solid Phase ◽  
Bubble Surface ◽  
Surface Forces ◽  
Gold Recovery ◽  
Gold Content ◽  
Hydrometallurgical Processing ◽  
Concentrate Yield ◽  
The Stability ◽  
Wetting Film ◽  
Gold Bearing

Increasing the economic efficiency of enrichment of refractory gold-bearing ores is possible by reducing the cost of opening sulphide gold-bearing concentrates by reducing the yield of flotation concentrate sent to pyro- or hydrometallurgical processing. It is important to maintain the achieved level of gold recovery into concentrate with a lower concentrate yield. In order to achieve this goal, the gold content in the main flotation operation is increased by mixing the rough concentrate separated from ½ part of the ore feed with another ½ part of it. Mixing in the flotation operation of products with a high level of wash ability (ability to separate) – initial feed and rough concentrate – is identical to an increase in the content of the extractable component in the original ore. In accordance with the new regime of flotation, the process is carried out in cold slurry with bubbles filled with hot steam. The physical basis of the new flotation regime is the dependence of the surface properties of air bubbles and surface forces that determine the stability of the liquid film separating the bubble and the particle on the temperature, which increases due to the heat of the vapor-liquid phase transition. Radial oscillations of the bubble surface as a result of pressure pulsations during condensation and vapor evaporation and surface thermal flows of liquid in the wetting film are factors that provide an increase in the completeness of gold recovery and the selectivity of flotation adhesion obtained in ore flotation experiments. In laboratory conditions, a comparison was made of the indicators obtained during the dressing of gold-bearing ores according to the factory and new schemes. It was revealed that the use of the developed technology allows, with a lower concentrate yield, to obtain an increase of 7.06% abs. extraction of gold into a concentrate of the best quality. A decrease in gold losses with flotation tailings is a consequence of an increase in the number of particles reaching the bubble surface due to radial oscillations of its surface and a weakening of the stability of the wetting film by the thermo-capillary mechanism. An increase in adhesion selectivity can be interpreted using the concept of surface forces of structural origin – an increase in the forces of hydrophobic attraction and hydrophilic repulsion with increasing temperature. The interaction of vapor bubbles with nanobubbles on the surface of the solid phase (wetting by the Cassie-Baxter mechanism) ensures efficient particle recovery by the coalescence mechanism of flotation.

Laser-photometric lump separation of gold-bearing ore

2020 ◽  
pp. 16-22
Author(s):  
V. A. Rassulov ◽  
◽  
E. V. Nerushchenko ◽  
Keyword(s):  
High Efficiency ◽  
Separation Method ◽  
Separation Performance ◽  
Low Grade ◽  
Gold Content ◽  
High Grade ◽  
Pilot Testing ◽  
Ore Minerals ◽  
Concentrate Yield ◽  
Gold Bearing

This paper establishes the conditions for selecting the optimal lump separation method based on the values of indicator properties of the ore minerals and demonstrates respective pilot testing results for low-grade quartz-type sulfide gold-bearing ores. The studies have shown the high efficiency of laser-photometric processing of ores with low contents of finely disseminated ore components, for which other methods are ineffective. On the example of ore from the Natalka deposit, it has been shown that acceptable lump separation performance requires division of the original ore into high-grade balance ore (the separation of which would be impractical), low-grade balance ore (to be subjected to lump separation), and an off-balance mineralized mass. Lump processing remains efficient up to ore temperatures of minus 15 °C, if rinsed with 4 °C water. The following concentration indicators were achieved for the lean ore of the process sample taken from the Alternativny section at ore temperatures above minus 15 °С: with the concentrate yield of 20 to 28 %, the gold content increases by 3.0–4.5, with an average level of metal losses in the tailings of approximately 13 %. At ore temperatures down to minus 21 °C, when an opaque ice film with the thickness of over 1 mm is formed on the lump during its screening with washing, metal losses in the separation tailings become 2.0–2.5 times higher. The authors are grateful to the employees of TOMRA, CC of CJSC Polyus Zoloto, Natalka FMS department of OJSC RiM, and FSBI VIMS, who assisted in the pre-concentration technology testing for the ore of the Natalka deposit.

Development of a combined processing technology for low-sulfide gold-bearing ores

2021 ◽  
pp. 3-8
Author(s):  
A. K. Koyzhanova ◽  
B. K. Kenzhaliev ◽  
D. R. Magomedov ◽  
N. N. Abdyldaev
Keyword(s):  
Raw Materials ◽  
Gold Recovery ◽  
Gold Content ◽  
Ministry Of Education ◽  
Gravity Concentration ◽  
Laboratory Equipment ◽  
Sorption Leaching ◽  
The Republic ◽  
Processing Circuit ◽  
Gold Bearing

This paper presents the results of laboratory dressability studies for low-sulfide gold-bearing ores using combined processing and subsequent oxidation leaching of the resulting combined concentrate. According to the current raw materials processing circuit used at the Sekisovskoye deposit, gravity concentration experiments were first carried out using the following laboratory equipment: a Knelson KSMD 3 centrifugal concentrator, an SKO-05 concentration table, and a two-chamber diaphragm jigging machine (i.e., OML by TsNIGRI). A significant portion (0.5 to 1.0 g/t) of the gold remains in the gravity concentration tailings. Subsequent flotation experiments for the tailings suggest that additional gold recovery is possible. The gold content in the final flotation tailings was in the range of 0.15–0.25 g/t. The final gold recovery in the combined process was therefore 93.7–96.5 %. The subsequent sorption cyanidation of the concentrate according to the current processing circuit allows depositing an average of 75.0–80.0 % Au on the coal. At the same time, the residual gold content in the sorption leaching tailings is significant and amounts to 3.6–7.5 g/t. The preliminary oxidation experiments for the concentrate slurry indicate the possibility of a more complete gold recovery with subsequent leaching, including sorption leaching. The residual gold content in the cakes was measured at 0.7–1.5 g/t, which ultimately yielded 95–96 % recovery at the leaching stage. The research was completed with the financial support of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan under grant No. АР05130143.

scholarly journals Mineralogical and Geochemical Characterization of Gold Bearing Quartz Veins and Soils in Parts of Maru Schist Belt Area, Northwestern Nigeria

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Samson Adeleke Oke ◽  
Akinlolu Festus Abimbola ◽  
Dieter Rammlmair
Keyword(s):  
Gold Content ◽  
X Ray Diffraction ◽  
Geochemical Characterization ◽  
X Ray ◽  
Quartz Veins ◽  
Magmatic Fluids ◽  
Geochemical Association ◽  
Ore Minerals ◽  
Gold Bearing

Epigenetic, N-S, NNE-SSW quartz veins crosscut metapelites and metagabbro in Maru area. The objectives of this work were to study field, mineralogy, and geochemical characteristics of gold bearing quartz veins and soils. Euhedral and polygonal magnetite with hematite constituted the major ore minerals. Quartz occurred as main gangue phase with appreciable sericite and chlorite. The mineralogy of soil retrieved from twelve minor gold fields examined with X-ray diffraction is quartz ± albite ± microcline ± muscovite ± hornblende ± magnetite ± illite ± kaolinite ± halloysite ± smectite ± goethite ± vermiculite ± chlorite. The concentration of gold in quartz vein varies from 10.0 to 6280.0 ppb with appreciable Pb (3.5–157.0 ppm) and ΣREE (3.6 to 82.9 ppm). Gold content in soil varies from <5.0 to 5700.0 ppb. The soil is characterized by As ± Sb gold’s pathfinder geochemical association. Multidata set analysis revealed most favourable areas for gold. Possibility of magmatic fluids as part of ore constituents is feasible due to presence of several intrusions close to quartz veins. Based on field, mineralogical, and geochemical evidences, ore fluids may have been derived from fracturing, metamorphic dewatering, crustal devolatilization of sedimentary, gabbroic protoliths, and emplaced in an orogenic setting.

scholarly journals Research into thickening processes of concentrates of gold-bearing ores

2021 ◽  
Vol 25 (3) ◽  
pp. 391-401
Author(s):  
D. A. Chernigov ◽  
A. V. Bogorodskiy ◽  
R. N. Nabiulin ◽  
T. S. Mineeva
Keyword(s):  
Flow Rate ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
South Urals ◽  
Gold Content ◽  
Flotation Concentrate ◽  
Fine Grinding ◽  
Specific Performance ◽  
Ultra Fine Grinding ◽  
Gold Bearing

The aim was to improve the thickening of an ultra-fine flotation concentrate by efficient flocculants when processing refractory sulphide gold-bearing ores from South Urals deposits. The chemical ore composition was studied using gravimetric, atomic absorption, chemical, X-ray fluorescent, assay test and electron microprobe analytical methods. Particle size analysis of the ultra-fine flotation concentrate under study was performed using a Malvern Hydro Mastersizer 2000MU analyser (Malvern Panalytical Ltd, UK). In thickening experiments, samples with the same composition after the ultra-fine grinding process were used. The gold content in the ore was determined (22.8 g/t) based on analytical studies on the material composition of samples. At least 92% of the final grain size class is -20 microns. Laboratory tests performed on eight samples containing polyacrylamide-based flocculants revealed an optimal A44 flocculant (produced in China). The flocculant meets the requirements for minimum flow rate, deposition rate and L:S ratio. The specific performance of the JX20 radial thickener (JPMFex Corp. Ltd., China) was calculated. The optimal flocculant flow rate is 200 g/t per 1 t of thickened material, leading to thickening 50 t of pulp per 1 m2 of thickener per day. The A44 flocculant is recommended for pilot testing. Thus, developing, testing and implementing fundamentally new reagents and improving existing technologies of processing gold-containing ores and concentrates are necessary to intensify the ore dewatering processes after ultra-fine grinding.

scholarly journals Studies on heap leaching of gold with the addition of sodium acetate as an intensifying reagent

2020 ◽  
pp. 25-30
Author(s):  
Ye. K. Yessengarayev ◽  
B. S. Baimbetov ◽  
B. N. Surimbayev
Keyword(s):  
Sodium Acetate ◽  
Heap Leaching ◽  
Gold Recovery ◽  
Gold Content ◽  
Electron Probe Analysis ◽  
Crushed Material ◽  
Urgent Task ◽  
Cyanide Consumption ◽  
Crushed Ore ◽  
Gold Bearing

One of the cheapest methods of extracting gold is heap leaching. However, the recovery of gold by this method is relatively low, compared with cyanidation of the crushed material, so the search for the ways to intensify leaching and increase gold recovery is an urgent task. Investigations on heap leaching of gold from the gold-bearing ore of the Sari Gunay deposit were conducted using a promising reagent sodium acetate to intensify the heap leaching process. The results of assay-gravimetric, chemical, mineralogical and granulometric analyses of oxidized ore are presented. The average gold content in the ore was 2.90 g/t. According to the electron probe analysis, gold in the ore is present in the form of fine (micron) inclusions in minerals and ore rocks. Comparative studies on heap leaching of gold from the crushed ore with a grain size of –20 + 0 mm with the addition of sodium acetate and without that were carried out. The degree of gold recovery with sodium acetate at a flow rate of 0.5 kg/t was 58.74%, that without sodium acetate was 54.69%, i.e. the addition of the reagent provides an increase in recovery of more than 4%. Leaching with the addition of the reagent also reduces sodium cyanide consumption from 0.65 to 0.59 kg/t. The research results have shown that sodium acetate can be used to intensify the process of heap leaching of gold when the ore size is –20+0 mm.

scholarly journals Developing the technology of associated gold recovery when concentrating copper-pyrite ore

2021 ◽  
Vol 1 (7) ◽  
pp. 35-44
Author(s):  
Sergei I. Evdokimov ◽  
◽  
Tatiana E. Gerasimenko ◽  
Keyword(s):  
Light Fraction ◽  
Gold Recovery ◽  
Shaking Table ◽  
Fine Tuning ◽  
Closed Circuit ◽  
Gold Content ◽  
Cone Crusher ◽  
Copper Pyrite ◽  
Technical Measures ◽  
Gold Bearing

Research objective is to address an up to date task of developing the technology of associated gold recovery from complex ore. Object of research is the gold-bearing copper-pyrite ore. Gold was recovered in laboratory conditions with the use of gravity methods of mineral separation. Research tools. Rational modes of machinery operation have been determined through mathematical planning of experiments including the obtained results processing by mathematical and statistical methods. Methods of research. Gold was recovered in the grinding-classification circuit based on a seriesinstalled short-cone hydrocyclone, a jigging machine and a shaking table. Research results. The developed jig mode differs from the existing ones by the closed-circuit of jig machine chambers: from the feed of the second (in the direction of the light fraction travel) jig chamber, the light fraction (tailings) and undersize product – fraction with the increased content of accessory minerals (rough concentrate) are separated. The rough concentrate in the second chamber is directed to the first chamber of the machine, where the finished jig concentrate is obtained in the form of an undersize product. The light fraction moves from the first chamber to the second and is removed from the machine through the tail board. When fine-tuning the heavy fraction of jigging on a shaking table, it is recommended to mix 1/2 part of the initial feed of the tables with the rough concentrate isolated from the other 1/2 of the original feed. The new jigging mode and the scheme of concentration on the tables provide an increase in the gold content in the initial feed of the apparatus, which is the reason for a decrease in gold losses with the tails of the gravity circuit. Research relevance. Gold recovery increment by 4.77% was obtained due to the use of all three recommended scientific and technical measures, namely sands concentration in a short head cone crusher on a jig, switching the jig chambers to a closed circuit, and jet motion of concentrates on shaking tables. Scope of the results. The results should be applied when concentrating ore containing free (amalgamable) gold, as well as gold-bearing pyrite.

Thermal Behaviors of Passively-Cooled Hybrid Fin Heat Sinks for Lightweight and High Performance Thermal Management

2015 ◽  
Author(s):  
Nico Setiawan Effendi ◽  
Kyoung Joon Kim
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
High Performance ◽  
Heat Dissipation ◽  
Computational Study ◽  
Heat Sinks ◽  
Channel Diameter ◽  
Internal Channel ◽  
Study Results ◽  
Parametric Effects

A computational study is conducted to explore thermal performances of natural convection hybrid fin heat sinks (HF HSs). The proposed HF HSs are a hollow hybrid fin heat sink (HHF HS) and a solid hybrid fin heat sink (SHF HS). Parametric effects such as a fin spacing, an internal channel diameter, a heat dissipation on the performance of HF HSs are investigated by CFD analysis. Study results show that the thermal resistance of the HS increases while the mass-multiplied thermal resistance of the HS decreases associated with the increase of the channel diameter. The results also shows the thermal resistance of the SHF HS is 13% smaller, and the mass-multiplied thermal resistance of the HHF HS is 32% smaller compared with the pin fin heat sink (PF HS). These interesting results are mainly due to integrated effects of the mass-reduction, the surface area enhancement, and the heat pumping via the internal channel. Such better performances of HF HSs show the feasibility of alternatives to the conventional PF HS especially for passive cooling of LED lighting modules.

Effects of Bile Salt Deconjugation by Probiotic Strains on the Survival of Antibiotic-Resistant Foodborne Pathogens under Simulated Gastric Conditions

2012 ◽  
Vol 75 (6) ◽  
pp. 1090-1098 ◽  
Author(s):  
XINLONG HE ◽  
YUNYUN ZOU ◽  
YOUNGJAE CHO ◽  
JUHEE AHN
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Foodborne Pathogens ◽  
Antibiotic Susceptibility ◽  
High Performance ◽  
Bifidobacterium Longum ◽  
Lactobacillus Rhamnosus ◽  
Antibiotic Resistant ◽  
Study Results ◽  
Probiotic Strains

This study was designed to evaluate the effects of bile acid deconjugation by probiotic strains on the antibiotic susceptibility of antibiotic-sensitive and multiple antibiotic–resistant Salmonella Typhimurium and Staphylococcus aureus. Eight probiotic strains, Bifidobacterium longum B6, Lactobacillus acidophilus ADH, Lactobacillus brevis KACC 10553, Lactobacillus casei KACC 12413, Lactobacillus paracasei ATCC 25598, Lactobacillus rhamnosus GG, Leuconostoc mesenteroides KACC 12312, and Pediococcus acidilactici KACC 12307, were used to examine bile acid tolerance. The ability to deconjugate bile acids was evaluated using both thin-layer chromatography and high-performance liquid chromatography. The antibiotic susceptibility testing was carried out to determine the synergistic inhibitory activity of deconjugated bile acids. L. acidophilus, L. brevis, and P. acidilactici showed the most tolerance to the conjugated bile acids. P. acidilactici deconjugated glycocholic acid and glycodeoxycholate from 3.18 and 3.09 mM to the detection limits, respectively. The antibiotic susceptibility of selected foodborne pathogens was increased by increasing the concentration of deconjugated bile acids. The study results are useful for understanding the relationship between bile acid deconjugation by probiotic strains and antibiotic susceptibility in the presence of deconjugated bile acids, and they may be useful for designing new probiotic-antibiotic combination therapy based on bile acid deconjugation.

scholarly journals Geochemistry of Umm Rus gold - quartz veins, Central Eastern Desert Egypt. A new contribution

2001 ◽  
Vol 34 (3) ◽  
pp. 1139
Author(s):  
O. A. KAMEL ◽  
M. M. EL MAHALLAWI ◽  
H. M. HELMY
Keyword(s):  
Hybrid Zone ◽  
Eastern Desert ◽  
Quartz Diorite ◽  
Low Grade ◽  
Gold Content ◽  
Strongly Correlated ◽  
Quartz Veins ◽  
Central Eastern Desert ◽  
Pan African ◽  
Gold Bearing

Gold-bearing quartz veins of the Umm Rus area occur at the south-eastern contact of a Precambrian granodiorite cupola within younger gabbros of 573-615 Ma belonging to the Pan African orogenic belt. The rocks are intruded within low-grade metasediments. At such contact, a hybrid zone is developed characterized by the occurrence of quartz diorite which grades into diorite and meta-ferrogabro. A limited number of mineralized quartz veins cut the granodiorite-gabbro complex. Different alteration zones are developed in the vicinity of the quartz veins. The quartz veins have two main trends; NS and N30 E, the latter one is usaually gold-bearing. The mineralized parts of the veins commonly consist of highly sheared and banded smoky quartz, and the gold content depends on the relation with the dykes. The element is strongly correlated with As and Ag, but moderately with Cu. Near to intermediate and basic dykes, the contents of Au, Ag and As are noticably increased

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