Gold recovery from flotation concentrate from gold mine tailings using dissolve smelting (original) (raw)
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International Journal of the Society of Materials Engineering for Resources
A pre-treatment method for upgrading gold from a polymetallic gold-zinc-lead ore by flotation was studied. X-ray diff raction analysis of the gold sulfi de ore showed that quartz, calcite, pyrite, sphalerite, and galena are the main constituents of the ore. The composition of the polymetallic ore contained 6.49 ppm Au, 3.48% Zn, 1.25% Pb, 17.98% Fe, and 20.36% S. Due to the complexity of the polymetallic ore, the gold recovery is generally low. The objective of this study is to develop a primary fl otation process to recover gold in a bulk sulfi de concentrate. The eff ects of particle size, collector type, fl otation time, and the slurry pH on the recoveries and grades of gold, zinc, and lead were investigated. The developed fl otation process consisted of rougher, scavenger, and cleaner stages. High recovery of gold was found to be linked with a high recovery of Pb which was achieved by the utilization of a mixture of collector AERO 7249 and PAX. The gold fl otation kinetics were fast with more than 50% of gold recovered within 5 minutes of fl otation. Under optimized fl otation conditions with rougher, scavenger, and cleaner stages, a total gold recovery of 88.36 % and a fi nal gold grade of 60.97 ppm were obtained. A total gold enrichment ratio of 9.4 was achieved, confi rming the viability of the fl otation method in upgrading the gold from the polymetallic sulfi de ore prior to further processing.
Transfer of Gold, Platinum and Non-Ferrous Metals from Matte to Slag by Flotation
Metals
One of the stages of extracting gold and platinum from sulfide materials and circulating slags is the melting stage in ore-thermal and electric furnaces, where the melt is separated into matte and slag. Gold, platinum, and non-ferrous metals are concentrated in the matte. However, a significant portion of them ends up in the slag, which reduces recovery and increases environmental pollution. The main reason for their transition to slag is the flotation of sulfide droplets by gas bubbles, a significant proportion of which occurs during the decomposition of sulfides. Gold and platinum are associated with matte droplets during flotation. Evaluation of adhesion showed that it is large and comparable to the cohesion of these metals. One of the options to reduce the loss of valuable components is to add fluxes to the slag. The influence of calcite and fluorite on the distribution of gold and platinum over the melting products of copper–nickel sulfide materials (matte and slag) has been ex...
Coal–oil assisted flotation for the gold recovery
Minerals Engineering, 2005
Using coal-oil agglomeration method for free or native gold recovery has been a research subject for many researchers over the years. In this study, a new approach ''coal-oil assisted gold flotation'' was used to recover gold particles. The coal-oil-gold agglomeration process considers the preferential wetting of coal and gold particles. The method takes advantage of the greater hydrophobicity and oleophilicity of coal and gold compared to that the most gangue materials. Unlike the previous studies about coal-oil-gold agglomeration, this method uses a very small amount of coal and agglomerating agents. Some experiments were conducted on synthetic gold ore samples to reveal the reaction of the coal-oil assisted gold flotation process against the size and the number of gold particles in the feed. It was observed that there is no significant difference in process gold recoveries for feeds assaying different Au. Although there was a slight decrease for coarse gold particles, the process seems to be effective for the recovery of gold grains as coarse as 300 lm. The decrease in the finest size (<53 lm) is considered to be the decrease in the collision efficiency between the agglomerates and the finest gold particles. The effect of changing coal quantity for constant ore and oil amounts was also investigated. The experiments showed that the process gives very similar results for both artificial and natural ore samples; the best results have been obtained by using 30/1 coal-oil ratio.
Concentration of Gold and Silver from the Antimonial Refractory Akoluk (Turkey) Ore by Flotation
In this study, recovery of gold and silver as a bulk sulphide concentrate by flotation from Akoluk antimonial refractory ore was investigated. It was shown that recoveries of Au, Ag and sulphides such as pyrite, stibnite, sphalerite, zinkenite and andorite decreased with reducing particle size. The highest metal recoveries (40% Au, 85% Ag, 40% Fe, 80% Sb and 98% Zn) were obtained at 25 µm particle size (d 80 ) and 10 min. flotation time. Addition of copper sulphate did not improve precious metal recovery. It was demonstrated that a sulphide concentrate with a silver grade of 1300 g/t (at 85% recovery) from the refractory Akoluk ore could be produced by froth flotation technique.
Characterisation and recovery of non-ferrous metals met in a copper-slag processed by flotation
2021
Detailed process oriented characterisation on representative samples from plant survey of the slag flotation plant belonging to Aurubis, Bulgaria has been realised in order to evaluate the mineralogical occurrences of Cu, Ni, Mo and Co bearing phases. The slag subjected to flotation consisted in majority of fayalite, magnetite-iron oxides and a glass-like phase. Ni and Mo have been found to be closely associated to magnetite and fayalite. The tailing from the slag flotation has been subjected to sulphation roasting followed by water leaching as a hydrometallurgical means to recover the remaining Cu, Mo, Ni and Co. Based on the various sulphation roasting conditions (acid dosage, duration, temperature) copper, nickel and cobalt were brought to solution to a different extent. Molybdenum was the most difficult to be rendered soluble due to its close association with iron, suspected to form an insoluble compound with it. Sulphation roasting performed at 350oC has secured the best extrac...
Minerals Engineering, 2016
Flotation performance of gold-bearing pyrite in refractory gold ores depend upon the interplay among process water chemistry, grinding chemistry, and ore mineralogy. The nature of pyrite itself (finely disseminated reactive pyrite vs. low reactivity) also plays a role in its surface reactivity. This paper reviews the experimental studies examining the interactions between grinding media, gold bearing pyrites and process water occurring during grinding of refractory gold ores and the effect of these interactions on flotation response of pyrite. The literature review reveals that the interactions are highly convoluted. It appears that the galvanic interactions between forged steel media and sulfide minerals ores are particularly significant after grinding of massive sulfide ores. Process water chemistry can also have an amplifying effect, as the process water becomes more laden with cyanide species and other ionic species. This paper should contribute an improved understanding of electrochemical and chemical processes occurring during the grinding of refractory gold ores, which is essential to improve flotation performance of pyrite. Judgement is reserved with regards to the overall economics associated with the use of various grinding media. Media consumption due to wear will have to be balanced against flotation recovery of gold bearing sulfides and whole circuit behaviour where gold in tailing may also be further recovered through leach processes.
2005
for their kind advice on my work. I would like to express special thanks to Mr. Kotaro Yonezu, who gave the useful and kind suggestion throughout this research work. I also would like to thank to all member of the economic geology laboratory, Earth Resources Engineering Department, Kyushu University, Japan, for giving their kind support and assistance during the research period. I am grateful to Kyushu University for providing Friendship Scholarship to fund the research. Sincere thanks are given to all members in the Department of Mining and Petroleum Engineering for their any assistance and warm collaborations. Finally, I would like to express the highest gratitude to my parents, without whose constant support, I would probably have given up long ago.
Increase in the Free Finely-Dispersed Gold Recovery in the Flotation Cycle
Journal of Ecological Engineering
This article presents the results of a comparative study for the increase in the free finely dispersed gold recovery from the gold-bearing ore produced in a deposit in Kazakhstan. The following minerals were identified in the sample under X-ray phase analysis: chalcopyrite and pyrite, as well as in a finely disseminated state in silicate minerals. Gold in the ore is present mainly (40.09%) in the free form under the results of phase analysis. Flotation tests of ore beneficiation were performed in FML-1 and FML-3 flotation machines with chamber volumes of 1.0 and 3.0 liters. A flotation combined concentrate with a gold content of 15.3 g/t was obtained (concentrate yield 9.45%), with gold recovery into concentrate 82.79% in the optimal mode: the grind of 90% in the class-0.071 mm; consumption of reagents: C7 foaming agent-30 and 60 g/t, sodium butyl xanthate-60 and 120 g/t; the time of the main flotation-10 minutes, the control flotation-7 minutes, at pH = 9. Flotation tailings contained 0.33 g/t of gold. The recovery showed a fairly high 84.42% (yield of the total concentrate 20.93%) with the gold content of 7.1 g/t with the use of a sulfidizing agent (Na 2 S) and additional dispersion of the pulp at pH = 9.0. A gold-bearing concentrate was obtained containing 4.0 g/t Au at a fineness of-0.05 mm and 6.8 g/t Au at a fineness of +0.05 mm. The beneficiation of the pulp with a fineness of +0.05 mm gave the recovery into the final concentrate equal to 89.94%.
Enhancing the flotation recovery of copper minerals in smelter slags from Namibia prior to disposal
Heliyon, 2020
Namibia Custom Smelters (NCS) process a range of copper concentrates in their three furnaces, namely; top submerged lance, copper converter and reverberatory furnaces, in order to produce mattes and fayalitic slags. The copper content of the slags range between 0.8 to 5 wt. % and this is considered too high for disposal to the environment. Currently, the slags are sent to a milling and flotation plant for liberation and recovery of residual copper. The copper recoveries realized in the plant are much lower than expected and it has been postulated that some copper minerals may be occurring in forms that are more difficult to float like oxides or fine disseminations in the gangue matrix. Mineralogical analysis of the slag samples was done using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The analysis did not reveal the presence of copper oxide minerals, however most scans showed copper sulphide minerals as free grains and some finely disseminated in fayalite gangue. In the first phase of the present experimental studies, the slags were milled to 75% passing 45 microns, which is the degree of milling done in the existing plant mill-float circuit. A range of commercial flotation reagents that include xanthates, dithiophosphates, mercaptobenzothiazole, thionocarbamates, fatty acids, sulphides and sulphates were used in the flotation test-work. The copper recoveries obtained in the mill-float stage were between 70 - 80%. In the second phase of the study, the flotation tailings were further milled to 90% passing 45 microns and floated. The cumulative copper recoveries increased markedly to over 90%, which represents a significant improvement in comparison to the recoveries obtained from the mill-float process. Sodium alkyl dithiophosphate, mercaptobenzothiazole (FC7245) was found to be the secondary flotation reagent that gave the best copper recoveries.