scholarly journals Investigating the Electrochemical Interaction of a Thiol Collector with Chalcopyrite and Galena in the Presence of a Mixed Microbial Community

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 553
Author(s):  
Ngoni Mhonde ◽  
Mariette Smart ◽  
Kirsten Corin ◽  
Nora Schreithofer
Keyword(s):  
Microbial Community ◽  
Electrochemical Behaviour ◽  
Processing Plant ◽  
Flotation Process ◽  
Sulphide Minerals ◽  
Cell Counts ◽  
Sodium Ethyl ◽  
Mineral Beneficiation ◽  
Mixed Microbial Community ◽  
Flotation Performance

High microbial cell counts have been recorded in sewage waters employed as process water in mineral beneficiation plants across the world. The presence of these microbes can negatively impact flotation performance through mineral passivation, although some microbes improve flotation performance as investigated in various bio-flotation studies. The current study aims to understand the electrochemical behaviour of minerals in the presence of a sodium ethyl xanthate (SEX) collector and microbes originating from a sulphide ore processing plant in South Africa. The electrochemical response was correlated to observe flotation performance. Mixed potential measurements were conducted in parallel to microflotation tests, to assess the hydrophilicity or hydrophobicity induced on sulphide minerals adapted to microbe-laden synthetic plant water. Sulphide minerals’ mixed potentials and interactions of SEX with sulphide minerals were dramatically reduced in the presence of the mixed microbial community (MMC). The observations were correlated with poor flotation efficacy noted in microflotation tests. These fundamental results shed light on how the adsorption of thiol collectors on sulphide minerals is adversely affected by microbes, prompting a discussion on flotation process monitoring when mineral beneficiation is conducted using microbe-laden water.

scholarly journals Effects of Cations/Anions in Recycled Tailing Water on Cationic Reverse Flotation of Iron Oxides

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 161 ◽  
Author(s):  
Min Tang ◽  
Shuming Wen
Keyword(s):  
Iron Oxides ◽  
Outer Sphere ◽  
Processing Plant ◽  
Reverse Flotation ◽  
Surface Complexes ◽  
Flotation Process ◽  
Potential Measurement ◽  
Local Plant ◽  
Fine Quartz ◽  
Flotation Performance

It is well known that reverse flotation performance of iron oxides is affected by water quality. Since many potential variations among water sources recycling in a mineral processing plant bring unpredictable effects on the flotation system of iron oxides: disturbing ions/compounds, pH, hardness, residual reagents, etc. In this study, the recycled tailing water from a local plant, characteristically constituting of Ca2+, Mg2+, Na+, K+, Al3+, Fe3+, Cl−, SO42− etc., was introduced into the cationic reverse flotation process of an iron ore. A series of bench flotation tests using iron ores, micro-flotation tests using pure fine quartz, water chemical analyses, and zeta potential measurement were conducted with the objective of identifying the possible influences of both cations and anions in the recycled tailing water on the flotation performance. The flotation results pointed out that the cation with higher valency had more severe influences on the recovery of iron oxides. The formation of the pH-dependent surface complexes on mineral surfaces, for example, Fe(OH)+, Fe(OH)2+, and Fe(OH)3 resulted from Fe3+ ions adsorption, contributed to the less negative zeta potentials of the quartz, and consequently weakened its interaction with the amine collector. It is worthy to note that SO42− ions seem to have a more positive effect on the recovery of iron oxides than Cl− ions. This is probably attributed to the formation of inner/outer- sphere surface complexes on the iron oxides, inhibiting the dissolution of the iron ions/species, and the coordination with these cations from the recycled tailing water, shielding their disturbances in the flotation.

Microbial Community Analysis inside a Biooxidation Heap for Gold Recovery in Equador

2017 ◽  
Vol 262 ◽  
pp. 135-138 ◽  
Author(s):  
Carlos L. Aspiazu ◽  
Paulina Aguirre ◽  
Sabrina Hedrich ◽  
Axel Schippers
Keyword(s):  
Microbial Community ◽  
Fine Fraction ◽  
Community Analysis ◽  
Gold Recovery ◽  
Microbial Community Analysis ◽  
Most Probable Number ◽  
Rrna Gene ◽  
Probable Number ◽  
Cell Numbers ◽  
Cell Counts

In a mine owned by the company Orenas S.A. (Equador), a biooxidation process for gold recovery has been developed. Refractory gold ore was crushed, milled and 500 ton of flotation concentrate was agglomerated by coating a support rock. This was piled up on a liner and the biooxidation process in the heap of 35x25x6 m3 was run for approximately 150 days. The oxidized material was subsequently removed for further processing. An outcrop allowed for depth dependent sampling of altogether 36 samples at three sites over the complete depth of 6 m. The fine fraction was removed from the host rock and sent to the laboratory for analysis of the microbial community. The pH ranged between 2.2 and 2.9. Total cell counts determined via counting under a fluorescence microscope after SYBR Green staining indicated a high microbial colonialization of the heap in all depths between 106 to 109 cells per g concentrate, however the highest cell numbers were mainly found in the upper 50 cm. Most-probable-number determination of living, acidophilic iron (II)-oxidizers for one site also revealed a decrease of cell numbers with depth (between 104 to 108 cells per g concentrate). Further molecular analyses of the community composition based on extracted DNA and 16S rRNA gene analyses by TRFLP and qPCR revealed a complex archaeal and bacterial community within the heap. It can be stated that an active community of acidophiles runs the biooxidation process in all sampled parts of the heap.

scholarly journals Mineralogical Prediction of Flotation Performance for a Sediment-Hosted Copper–Cobalt Sulphide Ore

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 474 ◽  
Author(s):  
Laurens T. Tijsseling ◽  
Quentin Dehaine ◽  
Gavyn K. Rollinson ◽  
Hylke J. Glass
Keyword(s):  
Cross Validation ◽  
Democratic Republic Of Congo ◽  
Sulphide Minerals ◽  
Quantitative Correlation ◽  
Sulphide Ore ◽  
Mineralogical Characteristics ◽  
Cobalt Sulphide ◽  
Quantitative Understanding ◽  
Flotation Performance ◽  
Leave One Out

As part of a study investigating the influence of mineralogical variability in a sediment hosted copper–cobalt deposit in the Democratic Republic of Congo on flotation performance, the flotation of nine sulphide ore samples was investigated through laboratory batch kinetics tests and quantitative mineral analyses. Using a range of ore samples from the same deposit the influence of mineralogy on flotation performance was studied. Characterisation of the samples through QEMSCAN showed that bornite, chalcopyrite, chalcocite and carrollite are the main copper-bearing sulphide minerals while carrollite is the only cobalt-bearing mineral. Mineralogical characteristics were averaged per sample to allow for a quantitative correlation with flotation performance parameters. Equilibrium recoveries, rate constants and final grades of the samples were correlated to the feed mineralogy through Multiple Linear Regression (MLR). Target sulphide minerals content and particle size, magnesiochlorite content, carrollite liberation and association of the copper and cobalt minerals with magnesiochlorite and dolomite were used to predict flotation performance. Leave One Out Cross Validation (LOOCV) revealed that the final copper and cobalt grades are predicted with an R2 of 0.80 and 0.93 and Root Mean Square Error of Cross Validation (RMSECV) of 4.41% and 1.34%. The recovery of cobalt and copper with time can be predicted with an R2 of 0.94 for both and an overall test error of 4.70% and 5.14%. Overall, it was shown that quantitative understanding of changes in mineralogy allows for prediction of changes in flotation performance.

Using a New Bulk Flotation Process to Enhance the Recovery of Mineral Beneficiation in a Lead-Zinc Sulfide-Oxide Mixed Ore

2013 ◽  
Vol 634-638 ◽  
pp. 3545-3550
Author(s):  
Yi Qiang Liang ◽  
Xu Dong Zhang ◽  
Han Ping Zhang ◽  
Mei Hua Liu
Keyword(s):  
Zinc Sulfide ◽  
Phase Analysis ◽  
Sem Analysis ◽  
Flotation Process ◽  
Oxidation Rates ◽  
Lead And Zinc ◽  
Mineral Beneficiation ◽  
Lead Zinc ◽  
Important Means ◽  
Considerable Benefit

The properties of a lead-zinc ore are investigated by XRD and SEM analysis methods. Results show that the ore assays 1.27 per cent Pb and 1.62 per cent Zn, mainly occurring in the form of sulfide minerals. Through lead and zinc phase analysis, it is known that the distribution of galena reaches 63.78 per cent, and that of sphalerite is up to 77.16 per cent. And the oxidation rates of lead and zinc will become much more serious as the depth of exploitation increases, which is a great trouble that the mine faces with. So how to improve the recovery of mineral beneficiation is an important means to enhance the economical benefits in the mine. Many tests work have been done to develop a new bulk flotation process to enhance the Pb and Zn recovery. Flotation results of the closed circuit test indicate that the Pb and Zn recovery from the new bulk flotation process can be increase by 10 per cent and 2 per cent, respectively, which makes very considerable benefit for the mine.

scholarly journals Mineral Liberation: A Case Study for Buzwagi Gold Mine

2021 ◽  
Vol 47 (3) ◽  
pp. 892-905
Author(s):  
Alphonce Wikedzi ◽  
Thomas Leißner
Keyword(s):  
Grain Size ◽  
Gold Mine ◽  
Flotation Process ◽  
Mineral Liberation ◽  
Process Plant ◽  
Automated Mineralogy ◽  
Flotation Performance ◽  
Automated Scanning ◽  
Scanning Electron

Buzwagi Gold Mine (BGM) process plant was designed such that, after secondary grinding, gold and copper are recovered by flotation. However, the flotation circuit had been inefficient, and as a result, cyanidation of flotation tailings is currently conducted to improve gold recovery. The inefficient flotation is suspected to be due to mineralogical variations of ores treated. Hence, mineral liberation characteristics of three ore blends treated by BGM were investigated by automated Scanning Electron Microscope (SEM) whereby five fractions (i.e.  -1 +0.5 mm, -0.5 +0.25 mm, -0.25 +0.125 mm, -0.125 +0.063 mm and -0.063 mm) were used. It was found that pyrite-pyrrhotite is the major valuable phase and the host of gold. Furthermore, pyrite-pyrrhotite was liberated at relatively coarse size (i.e. approx. 200-400 µm). Additionally, quartz, feldspar, muscovite and biotite-chlorite were the main gangue phases. Pyrite-pyrrhotite grain size distribution was coarser than most gangue minerals in the ore blends, indicating that most of the milling energy was lost in grinding of gangue phases. Since gold host phase (pyrite-pyrrhotite) was liberated at coarser sizes, it was concluded that the efficiency of gravity circuit could not be affected. However, the flotation process will still require finer feed (i.e. ≤ 125 µm) for its efficiency. Keywords: Mineral liberation; Gold ore blends; Flotation Performance; Pyrite-pyrrhotite; Automated Mineralogy

scholarly journals A New Collector for Effectively Increasing Recovery in Copper Oxide Ore-Staged Flotation

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 595
Author(s):  
Renfeng Zhu ◽  
Guohua Gu ◽  
Zhixiang Chen ◽  
Yanhong Wang ◽  
Siyu Song
Keyword(s):  
Particle Size ◽  
Copper Oxide ◽  
High Efficiency ◽  
Average Particle Size ◽  
Economic Feasibility ◽  
Processing Plant ◽  
Average Particle ◽  
Entrainment Rate ◽  
Flotation Process ◽  
New Type

A new method, staged flotation for effectively increasing the recovery of ultra-fine copper oxide ore with a new type of collector (ZH-1, C3-5 carbon chain xanthate) is proposed for the first time. The flotation process and mechanism were examined by flotation tests, entrainment rate analysis, laser particle size experiments and microscopic imagery as well as economic feasibility analysis. It was demonstrated that the collector isoamyl sodium xanthate (ISX) shows a good collection ability (recovery exceeded 95%) for azurite, but the recovery was relatively much lower for malachite (only near 80%) due to the different particle size distribution. The new type of xanthate ZH-1 has shown a high-efficiency collection performance for fine-grained malachite. The recovery achieved for −10 μm malachite was more than 95% when the ZH-1 dosage was 150 mg/L, while the average particle size of −10 μm malachite sharply increased from 4.641 μm to 9.631 μm. The batch flotation results indicated that the copper oxide flotation recovery increased from 79.67% to 83.38%, and the grade also raised from 18.08% to 18.14% after using the staged flotation technology with ZH-1 as collector during the flotation of −25 μm ore. It was confirmed that this technology was quite effective for the recovery of copper oxide at the Dishui Copper Processing Plant, which successfully increased its gross profit by 1.6 million US$ per year.

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