scholarly journals Application of Innovative Processes for Gold Recovery from Romanian Mining Wastes

2020 ◽  
Vol 15 (2) ◽  
pp. 29-37
Author(s):  
Stefano Ubaldini ◽  
Igor Povar ◽  
Tudor Lupascu ◽  
Oxana Spinu ◽  
Francesca Trapasso ◽  
...  
Keyword(s):  
Laboratory Scale ◽  
Gold Recovery ◽  
Flow Sheet ◽  
Mining Wastes ◽  
Hydrometallurgical Process ◽  
Gold Extraction ◽  
Process Solution ◽  
Complete Circuit ◽  
Adsorption Desorption ◽  
Integrated Flow Sheet

The application of a new hydrometallurgical process for gold extraction by thiosulphate leaching from Romanian mining wastes, coming from Balan and Deva deposits, was studied. There was obtained 85% of Au extraction after leaching; moreover, an integrated flow-sheet, including recycling of process solution and carbon, was outlined, based on results obtained at a laboratory scale, using a schematic chemical circuit of treatment. Global recovery of the process (leaching-adsorption-desorption-electrodeposition) of about 75-80% of Au was achieved. The developed integrated flow-sheet, allows to recycle the reagents during the process, with a loss of only 5-10%, in particular thiosulphate and alcohol, for each complete circuit of treatment.

scholarly journals Performance-Based Selection of the Cathode Material for the Electrodeposition-Redox Replacement Process of Gold Recovery from Chloride Solutions

2021 ◽  
Author(s):  
Ivan Korolev ◽  
Kirsi Yliniemi ◽  
Mari Lindgren ◽  
Leena Carpén ◽  
Mari Lundström
Keyword(s):  
Material Selection ◽  
Recovery Process ◽  
Multiple Attribute Decision Making ◽  
Gold Recovery ◽  
Process Efficiency ◽  
Gold Extraction ◽  
Corrosion Properties ◽  
Multiple Attribute ◽  
Replacement Process ◽  
Cathode Substrate

AbstractRecently, an emerging electrodeposition-redox replacement (EDRR) method was demonstrated to provide exceptionally efficient gold recovery from cyanide-free hydrometallurgical solutions. However, the effect of electrode material and its corrosion resistance in this process was overlooked, even though the EDRR process is carried out in extremely corrosive, acidic chloride solution that also contains significant amounts of strong oxidants, i.e., cupric ions. In the current study, nickel alloy C-2000, stainless steels 316L and 654SMO, and grade 2 titanium were for the first time critically evaluated as potential cathode materials for EDRR. The particular emphasis was placed on better understanding of the effect of cathode substrate on the overall efficiency of the gold recovery process. The use of a multiple attribute decision-making method of material selection allowed reaching of a well-founded compromise between the corrosion properties of the electrodes and process efficiency of gold extraction. The 654SMO steel demonstrated outstanding performance among the examined materials, as it enabled gold recovery of 28.1 pct after 3000 EDRR cycles, while its corrosion rate (CR) was only 0.02 mm/year.

scholarly journals Bio-Oxidation of a Double Refractory Gold Ore and Investigation of Preg-Robbing of Gold from Thiourea Solution

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1216
Author(s):  
Rui Xu ◽  
Qian Li ◽  
Feiyu Meng ◽  
Yongbin Yang ◽  
Bin Xu ◽  
...  
Keyword(s):  
Mixed Culture ◽  
Active Sites ◽  
Gold Recovery ◽  
Ftir Analysis ◽  
Gold Extraction ◽  
Gold Ores ◽  
Gold Ore ◽  
Thiourea Solution ◽  
Refractory Gold ◽  
Pure Cultures

Carbonaceous sulfidic gold ores are commonly double refractory and thus require pretreatment before gold extraction. In this paper, the capacity of pre-bio-oxidation can simultaneously decompose sulfides or deactivate carbonaceous matters (CM) from a double refractory gold ore (DRGO) using pure cultures of A. ferrooxidans or L. ferrooxidans, and a mixed culture containing A. ferrooxidans and L. ferrooxidans was investigated. The results showed that direct thiourea leaching of the as-received DRGO yielded only 28.7% gold extraction, which was due to the encapsulation of sulfides on gold and the gold adsorption of CM. After bio-oxidation, thiourea leaching of the DRGO resulted in gold extraction of over 75–80%. Moreover, bio-oxidation can effectively reduce the adsorption of carbon to gold. XRD, SEM-EDS and FTIR analysis showed that many oxygen-containing groups were introduced on the surface of DRGO during bio-oxidation, while the C=C bond was cleaved and the O–C–O and C–N bonds were degraded, causing a decrease in active sites for gold adsorption. Moreover, passivation materials such as jarosite were formed on the surface of DRGO, which might reduce the affinity of CM for gold in solutions. In addition, the cleavage of the S–S band indicated that sulfides were oxidized by bacteria. This work allows us to explain the applicability of pre-bio-oxidation for degrading both sulfides and CM and increasing gold recovery from DRGO in the thiourea system.

Combined bio-hydrometallurgical process for gold recovery from refractory stibnite

2000 ◽  
Vol 13 (14-15) ◽  
pp. 1641-1646 ◽  
Author(s):  
S Ubaldini ◽  
F Veglio ◽  
L Toro ◽  
C Abbruzzese
Keyword(s):  
Gold Recovery ◽  
Hydrometallurgical Process

scholarly journals On the possibility of flotation processing of technogenic gold-containing waste from enrichment plants

2021 ◽  
Author(s):  
L.V. Semushkina ◽  
◽  
S.M. Narbekova ◽  
Keyword(s):  
Chemical Analysis ◽  
Main Part ◽  
Gold Recovery ◽  
Butyl Xanthate ◽  
Flotation Reagent ◽  
Rational Analysis ◽  
Gold Extraction ◽  
Foaming Agent ◽  
Flotation Tailings ◽  
Fine Grained

The aim of the work is the flotation processing of gold-containing tailings using composite flotation (CF) agents. According to the results of chemical analysis, the studied tailings sample contains 0.39 g/t gold. The main part of the initial tailings sample is represented by rock-forming minerals such as quartz, clinochlore, microcline, tremolite, albite, calcite, and muscovite. According to the results of the rational analysis, 39.50% of gold is in the hard-to-recover form with quartz; 28.87% is in the form of fine-grained gold; 31.63% is in intergrowths with sulfides and rocks. The optimum reagent scheme of flotation processing of tailings was chosen: degree of regrinding of 95% of grade -0,074 mm, consumption of sodium butyl xanthate of 100 g/t, consumption of foaming agent T-92 of 30 g/t. Under the chosen reagent scheme the gold-containing concentrate containing 6,4 g/t gold at the recovery of 49,68% was obtained. Preliminary regrinding of tailings allows to increase the gold recovery in the blanks concentrates by 27.96%. The reagent scheme of flotation of gold-containing tailings with the application of composite flotation (CF) agent was tested. A composition of sodium butyl xanthate and reaeflot was used as a composite flotation reagent for the improvement of gold extraction from flotation tailings. Application of composite flotation (CF) agent pre-treated on the dispersant increases gold recovery into gold-containing concentrate by 4.65%, in comparison with the basic collector sodium butyl xanthogenate. Consumption of flotation agent CF is reduced by 20%.

scholarly journals Current methods of technogenic gold placer deposit mining with small size gold extraction technology

2021 ◽  
Vol 43 (4) ◽  
pp. 458-466
Author(s):  
S. A. Prokopiev ◽  
E. S. Prokopiev ◽  
I. V. Kadesnikov ◽  
N. A. Cherimichkina
Keyword(s):  
Raw Materials ◽  
Mineralogical Composition ◽  
Placer Deposit ◽  
Gold Recovery ◽  
Raw Material ◽  
Productive Capacity ◽  
Gold Content ◽  
Gold Placer ◽  
Gold Extraction ◽  
Extraction Technology

The purpose of this article is to conduct industrial tests of spiral separation technology on technogenic refractory raw materials. The object of the study is the Yurskoye gold placer deposit in the Republic of Sakha (Yakutia). An OKV-100 benefication complex with the productive capacity of 100 m3 /h by initial sands was set up in order to conduct pilot mining of the fine-grained tailings dumps of the Yurskoye deposit with the maximum extraction of small size gold. Sands supplied from the different sections of the technogenic deposit had different gold content, granulometric characteristics, and mineralogical composition. The study included experiments carried out at different initial feed; equipment was adjusted for specific raw material depending on productive capacity, liquid/solid ratio, product yield of the small size gold recovery module. The complex productivity was from 90 to 150 m3 /h. The yield and extraction of gold-bearing concentrate, as well as its gold content were determined. The pilot washing with the use of small size gold recovery technology resulted in the average additional gold recovery from sluice tailings of 19.07 %, which is a high indicator, given the low content of gold in technogenic placers. The technology under consideration can be used for the development of both technogenic and operated gold placer deposits.

Pretreatment of Refractory Gold Ores Using Cell-Free Extracts of P. chrysosporium: A Preliminary Study

2013 ◽  
Vol 825 ◽  
pp. 427-430 ◽  
Author(s):  
Grace Ofori-Sarpong ◽  
Kwadwo Osseo-Asare ◽  
Ming Tien
Keyword(s):  
Gold Recovery ◽  
Active Components ◽  
Gold Extraction ◽  
Promising Alternative ◽  
Gold Ores ◽  
Refractory Gold Ores ◽  
In Vitro Processing ◽  
Refractory Gold

The fungus Phanerochaete chrysosporium has been proven to biotransform refractory gold ores, leading to increase in gold recovery. This transformation has been attributed to enzymes secreted by the microbe. This paper reports the findings of preliminary investigations aimed at assessing the use of hydrogen peroxide and cell-free extracts from the fungus, P. chrysosporium, to effect biotransformation of sulphidic refractory gold ores. The investigations show that the total dissolved arsenic, iron and sulphur in solution were up to 5.2 wt%, 0.9 wt% and 6.0 wt% respectively from flotation concentrate after 72 hrs of treatment. Analysis for sulphide sulphur in the residual solids of the gold concentrate indicated about 25 wt% oxidation within 24 hours of treatment. In general, cell-free decomposition of the samples did not increase beyond 24 hours of contact time, possibly due to exhaustion of the active components. Gold extraction by cyanidation increased by 24% after 24-hr treatment with the cell-free extracts. Comparatively, cell-free (in vitro) treatment recorded 66% overall gold recovery as against 61% for whole cell (in vivo) after 72 hours of treatment. These initial results indicate clearly that in vitro processing is a promising alternative to in vivo processing of refractory gold ores using P. chrysosporium.

Gold recovery from very dilute solutions from a mine in closing process: Adsorption-desorption onto carbon materials

2017 ◽  
Vol 240 ◽  
pp. 549-555 ◽  
Author(s):  
Esmeralda Vences-Alvarez ◽  
Elías Razo-Flores ◽  
Isabel Lázaro ◽  
Roberto Briones-Gallardo ◽  
Guillermo Velasco-Martínez ◽  
...  
Keyword(s):  
Carbon Materials ◽  
Gold Recovery ◽  
Dilute Solutions ◽  
Adsorption Desorption

Effective methods for gold recovery from mining wastes at placers

2012 ◽  
Vol 48 (1) ◽  
pp. 198-202 ◽  
Author(s):  
V. S. Litvintsev ◽  
T. S. Banshchikova ◽  
N. A. Leonenko ◽  
V. S. Alekseev
Keyword(s):  
Gold Recovery ◽  
Mining Wastes

scholarly journals ISOLASI BAKTERI RESISTENSI MERKURI DARI LIMBAH PENAMBANGAN EMAS KABUPATEN BURU, MALUKU (Isolation of Mercury Resistance Bacteria from Gold Mining Waste in Buru District, Maluku)

2020 ◽  
Vol 27 (1) ◽  
pp. 33
Author(s):  
Rosita Mangesa ◽  
Kasmawati Kasmawati
Keyword(s):  
Gold Mining ◽  
Local Community ◽  
Mining Waste ◽  
Laboratory Scale ◽  
Mercury Resistance ◽  
Gold Extraction ◽  
Sampling Locations ◽  
The Impact

AbstrakPulau Buru merupakan salah satu pulau penambangan emas dan banyak dilakukan secara illegal dengan melibatkan penggunaan merkuri untuk alat bantu dalam proses ekstraksi emas melalui proses amalgamasi. Merkuri merupakan bahan kimia yang berbahaya dan bersifat toksik bagi manusia dan juga lingkungan, dan dampak dari penggunaan merkuri ini telah dirasakan oleh masyarakat setempat. Penelitian ini bertujuan untuk memperoleh bakteri yang resisten terhadap merkuri sehingga dapat digunakan dalam proses bioremediasi. Penelitian ini merupakan penelitian skala laboratorium dan dianalisis secara deskriptif. Hasil penelitian ini yaitu dari kedua lokasi pengambilan sampel diperoleh 17 isolat dengan morfologi yang berbeda-beda serta dari ke-17 isolat tersebut resisten terhadap merkuri.AbstractBuru Island is one of the gold mining islands and much of them are illegally that used mercury in gold extraction using uses mercury. Mercury is a chemical that is harmful and toxic to humans as well as the environment, and recently the impact of mercury use has been found by the local community. This study aims to obtain bacteria that are resistant to mercury so that it can be used in the bioremediation process. This research is a laboratory scale research and analyzed descriptively. The results of this study, namely from the two sampling locations obtained 17 isolates with different morphologies and from the 17 isolates were resistant to mercury.

scholarly journals Introduction of Mercury-Free Gold Extraction to Small-Scale Miners in the Cabo Delgado Province in Mozambique

2018 ◽  
Vol 8 (19) ◽  
Author(s):  
Birgitte Stoffersen ◽  
Peter WU Appel ◽  
Leoncio D Na-Oy ◽  
Asta Selloane Sekamane ◽  
Ivan Zahinos Ruiz ◽  
...  
Keyword(s):  
Urban Areas ◽  
Extraction Method ◽  
Extraction Methods ◽  
Gold Recovery ◽  
Small Scale ◽  
Gold Extraction ◽  
Governmental Organization ◽  
Free Gold ◽  
Financial Interests ◽  
Gold Bearing

Background. The majority of small-scale gold miners worldwide, including those in Mozambique, use mercury to extract gold. Over the last fifty years, gold production from small-scale mining has been accelerating and consequently the amount of mercury released to the environment has increased dramatically, causing major global health problems. In 2018, a team from the Danish non-governmental organization Diálogos introduced the mercury-free gold extraction method in the Cabo Delgado province in Mozambique in the villages of Waqueia and Nanlia. Objectives. The objective of this project was to teach local miners this method to reduce mercury pollution. An additional objective was to compare the local gold extraction method and the mercury-free gold extraction method in terms of gold recovery. The hypothesis was that the level of gold recovery would be higher with the mercury-free method compared to the locally used amalgamation method. Materials and Methods. An experimental study comparing the two gold extraction methods was carried out where local miners processed gold-bearing ore using their standard procedures with the amalgamation method and the Diálogos team processed an equivalent amount of gold-bearing ore with the mercury-free gold extraction method. The tests were carried out once at each mining site. Results. Under even circumstances in a controlled setting, the mercury-free method yielded up to 78% more gold than the amalgamation method normally used by the miners. Conclusions. The strengths of the mercury-free gold extraction method include low costs, higher gold yield, benign environmental impact, legality and needed chemicals are more readily available compared with the amalgamation method. However, the mercury-free method may be more time consuming than the amalgamation method, especially for beginners. Borax is typically available in developed urban areas, as it is commonly used in the welding industry and by jewelers, but can be hard to find in more remote villages. Competing Interests. The authors declare no competing financial interests.

Sign in / Sign up

Export Citation Format

Share Document