scholarly journals Zinc Recovery from Wulagen Sulfide Flotation Plant Tail by Applying Ether Amine Organic Collectors

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5365
Author(s):  
Zilong Ma ◽  
Lei Wang ◽  
Xiao Ni ◽  
Yinfei Liao ◽  
Zhian Liang
Keyword(s):  
Froth Flotation ◽  
Hydrocarbon Chain ◽  
Low Grade ◽  
Zinc Recovery ◽  
Flotation Tailings ◽  
Sulfide Flotation ◽  
Flotation Tailing ◽  
Flotation Performance ◽  
The Difference ◽  
Amine Adsorption

Separating oxidized zinc minerals from flotation tailings is always a challenge. In this study, a flotation tailing from Wulagen zinc mine in China (Zn grade < 1%) was processed using froth flotation with combinations of amines (OPA 10, OPA 1214, OPA 13, DDA) and Na2S to study the effects of these amines on the zinc recovery as well as their interactions with other reagents, aiming to screen out a proper reagent scheme to improve zinc separation from extremely low-grade zinc flotation tailings. The results show that different amines led to different flotation performance, and the collectors were ranked as OPA 1214, OPA 13, OPA 10 and DDA in a decreasing order based on flotation collectivity and selectivity. An increase in the concentration of each collector increased the zinc recovery but reduced the concentrate zinc grade. Interactions were also observed between different amines and Na2S and Na2SiO3, and OPA 1214 outdid the others in saving the usage of both the Na2S and Na2SiO3. The measured adsorption of collector onto smithsonite was found to correlate well with flotation test results. It was concluded that hydrocarbon chains can be held accountable for the difference in the flotation performance with different amines. The longer the hydrocarbon chain, the stronger the hydrophobic association ability of amine, which is conducive to the selective amine adsorption onto sulfurized smithsonite particles and hence the smithsonite flotation.

scholarly journals Probing the Effect of Water Recycling on Flotation through Anion Spiking Using a Low-Grade Cu–Ni–PGM Ore: The Effect of NO3−, SO42− and S2O32−

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 340
Author(s):  
Mathew Dzingai ◽  
Malibongwe S. Manono ◽  
Kirsten C. Corin
Keyword(s):  
Water Chemistry ◽  
Froth Flotation ◽  
Water Source ◽  
Threshold Concentration ◽  
Process Water ◽  
Low Grade ◽  
Unit Operations ◽  
Flotation Performance ◽  
Anion Distribution ◽  
Nickel Grade

Water scarcity necessitates the recycling of process water within mineral processing practices. This may however come with its disadvantages for unit operations such as froth flotation as this process is water intensive and sensitive to water chemistry. It is therefore important to monitor the water chemistry of the recycle stream of process water and any other water source to flotation. Monitoring the concentrations of the anions in recycled process water is therefore important to consider as these are speculated to impact flotation performance. Batch flotation tests were conducted using synthetically prepared plant water (3 SPW) with a TDS of 3069 mg/L as the baseline experiment. 3 SPW contained 528 mg/LNO3− and 720 mg/L SO42−, other anions and cations, and no S2O32−. Upon spiking 3 SPW with selected anions, viz, NO3−, SO42− and S2O32−, it was noted that NO3− and SO42− exhibited threshold concentrations while S2O32− did not show a threshold concentration for both copper and nickel grade. Spiking 3 SPW with 352 mg/L more of NO3− to a total 880 mg/L NO3− concentration resulted in the highest copper and nickel grade compared to 3 SPW while increasing the S2O32− from 60 to 78 mg/L increased nickel and copper grade. 720 to 1200 mg/L SO42− and 528 to 880 mg/L NO3− were deemed the concentration boundaries within which lies the threshold concentration above which flotation performance declines with respect to metal grades, while for S2O32− the threshold concentration lies outside the range considered for this study. Anion distribution between the pulp and the froth did not seem to impact the recovery of copper or nickel. Notably, the correlation between the concentrate grades and anion distribution between the froth and the pulp seemed to be ion dependent.

Impact of Pre-Desliming on Flotation of Low-Grade Zinc Oxide Ore from Lanping

2013 ◽  
Vol 634-638 ◽  
pp. 3385-3389
Author(s):  
Wen Juan Zhao ◽  
Dian Wen Liu ◽  
Xiao Lin Zhang ◽  
Shu Qin Zeng ◽  
Guo Yin Xu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Economic Benefit ◽  
Low Grade ◽  
Zinc Recovery ◽  
Calcium And Magnesium ◽  
Flotation Performance ◽  
The Impact

Zinc oxide ore from Lanping contained large amount of fine slime which badly deteriorated flotation performance, and it complexly intergrowed with plenty of alkaline gangues with calcium and magnesium. In order to investigate the impact of pre-desliming on flotation, experiments of direct flotation and pre-desliming flotation were carried out in the work. Finally, a zinc recovery of 88.73% with a Zn grade of 13.93% was obtained in direct flotation test, and a higher zinc recovery of 95.25% with a Zn grade of 13.56% was achieved by pre-desliming flotation. Pre-desliming flotation test was superior to direct flotation test, because of an increase of nearly 7% in zinc recovery under the condition of similar Zn grade. At the same time, dosage of sulfurization agent used in pre-desliming flotation was lower by 46.67% than that in direct flotation, which obviously improved the availability of sulfurization agent. So both product index and economic benefit were enhanced after pre-desliming.

scholarly journals Recovery of ZnO from lead-zinc flotation tailings by hydrometallurgical processes: XRD, SEM, and AFM studies

2020 ◽  
Vol 56 (1) ◽  
pp. 23-35
Author(s):  
K.T. Perek ◽  
B. Benli ◽  
C. Arslan ◽  
F. Arslan
Keyword(s):  
Cross Sections ◽  
Acid Leaching ◽  
Zinc Hydroxide ◽  
High Iron Content ◽  
Zinc Recovery ◽  
Flotation Tailings ◽  
H2so4 Concentration ◽  
Flotation Tailing ◽  
Iron And Zinc ◽  
Lead Zinc

The hydrometallurgical route of zinc hydroxide and synthesis of nanocrystalline ZnO is a particularly attractive method to recover oxidized lead and zinc from lead-zinc flotation tailings. In Turkey, lead-zinc complex/mixed ores along with high iron content are not suitable for conventional mineral processing methods and need hydrometallurgical treatments. Therefore, the control of iron during zinc processes is really important. In this study, hydrometallurgical process route for zinc recovery from Pb-Zn flotation tailings was investigated by considering the effects of H2SO4 concentration, leaching and roasting temperatures on the zinc dissolution considering the Eh-pH variations. The iron and zinc products were also individually examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images in order to compare before and after leaching, precipitation and roasting steps. 83.1% Zn and 91.6% Cd leaching efficiencies were obtained from Pb-Zn flotation tailing particles with the size range of 50-110 nm from AFM image cross-sections, while lead and iron were not dissolved. Elemental sulfur started to form and produce a layer around the particles or a partially agglomerated particle in the size of 170 nm during the sulphuric acid leaching. However, majority of the particles was determined to be less than 20 microns, and AFM images showed that the size reduction between the leached and unleached particles was over 50%. Selective precipitations of iron and zinc in the form of hydroxide were performed in high recovery efficiencies of 90.1% and 99%, respectively. After the heat treatment, nanocrystalline zincite clusters of 96.6% purity were produced in the ZnO mineral form and nearly 13 nm in size. Zinc can be successfully recovered and a flotation tailings ore can be a good candidate for the production of high technology needs of nanocrystalline ZnO nanoparticles.

Dynamic Scintigraphy of the Oesophagus in the Evaluation of Reflux Oesophagitis

1990 ◽  
Vol 29 (05) ◽  
pp. 204-209
Author(s):  
B. Ugarković ◽  
D. Ivančević ◽  
D. Babić ◽  
Ž. Babić
Keyword(s):  
Reflux Oesophagitis ◽  
Oesophageal Reflux ◽  
Low Grade ◽  
Time Activity ◽  
The Difference ◽  
Asymptomatic Subjects ◽  
Oesophageal Transit ◽  
Dynamic Scintigraphy ◽  
Positive Results ◽  
Reflux Œsophagitis

A method is presented which combines gastro-oesophageal reflux quantification and oesophageal transit measurement so as to differentiate true reflux from residual oesophageal activity. A group of 33 subjects with gastro-oesophageal reflux symptoms and endoscopically confirmed reflux oesophagitis and a group of 21 asymptomatic subjects with normal oesophageal, gastric and duodenal endoscopic findings were examined. The subjects were given 37 MBq 99mTc-Sn-colloid in saline orally and then scintiscanned dynamically. The gastro-oesophageal quantification was done after transit measurement and after the oesophageal time activity (to detect residual oesophageal activity) reached its minimum. The difference in the reflux indices between the two groups was highly significant. In low-grade oesophagitis measured reflux was lower than in higher grades of disease. Only 4.7% false-positive results were observed with a specificity of 95%, indicating that this method may be superior to methods published earlier.

scholarly journals Critical importance of pH and collector type on the flotation of sphalerite and galena from a low-grade lead–zinc ore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdolrahim Foroutan ◽  
Majid Abbas Zadeh Haji Abadi ◽  
Yaser Kianinia ◽  
Mahdi Ghadiri
Keyword(s):  
Iron Ore ◽  
Low Grade ◽  
Zinc Recovery ◽  
Flotation Process ◽  
Ph Values ◽  
Lead And Zinc ◽  
Optimum Ph ◽  
Iron And Zinc ◽  
Lead Zinc ◽  
Zinc Concentrate

AbstractCollector type and pulp pH play an important role in the lead–zinc ore flotation process. In the current study, the effect of pulp pH and the collector type parameters on the galena and sphalerite flotation from a complex lead–zinc–iron ore was investigated. The ethyl xanthate and Aero 3418 collectors were used for lead flotation and Aero 3477 and amyl xanthate for zinc flotation. It was found that maximum lead grade could be achieved by using Aero 3418 as collector at pH 8. Also, iron and zinc recoveries and grades were increased in the lead concentrate at lower pH which caused zinc recovery reduction in the zinc concentrate and decrease the lead grade concentrate. Furthermore, the results showed that the maximum zinc grade and recovery of 42.9% and 76.7% were achieved at pH 6 in the presence of Aero 3477 as collector. For both collectors at pH 5, Zinc recovery was increased around 2–3%; however, the iron recovery was also increased at this pH which reduced the zinc concentrate quality. Finally, pH 8 and pH 6 were selected as optimum pH values for lead and zinc flotation circuits, respectively.

scholarly journals Specific Ion Effects on the Behavior of Mixtures of Sodium Iso-Butyl Xanthate and Sodium Diethyl Dithiophosphate during the Flotation of a Cu-Ni-PGM Ore: Effects of CaCl2 and NaCl

2021 ◽  
Vol 6 (1) ◽  
pp. 22
Author(s):  
Malibongwe S. Manono ◽  
Katlego Matibidi ◽  
Kirsten C. Corin ◽  
Catherine K. Thubakgale ◽  
Iyiola O. Otunniyi ◽  
...  
Keyword(s):  
Froth Flotation ◽  
Monovalent Cation ◽  
Process Water ◽  
Polyvalent Cation ◽  
Flotation Reagents ◽  
Sulfide Flotation ◽  
Froth Stability ◽  
Ion Effects ◽  
The Relationship ◽  
Diethyl Dithiophosphate

Inorganic electrolytes present in the process water used during froth flotation may have both beneficial and detrimental effects. These effects are said to be ion specific, as some ions may result in enhanced froth stability, increased mineral recoveries and decreased concentrate grades, while others may bring the opposite effects. Onsite process water quality variations have intensified the need to understand the relationship between inorganic electrolytes and flotation reagents on flotation performance. The use of mixtures of thiol collectors in sulfide flotation is a common practice across the globe; however, very few investigations have considered these in process waters of varying compositions. This study considers the effect of common cations, Na+ and Ca2+, in process water on the behavior of mixtures of thiol collectors. Single-salt solutions of NaCl and CaCl2 at an ionic strength of 0.0213 mol·dm−3 were used to investigate the behavior of mixtures of two thiol collectors. These were carefully selected to understand how mixtures of thiol collectors behave in the presence of a monovalent cation versus a polyvalent cation. Bench-scale froth flotation tests were conducted using a Cu-Ni-PGM ore from the Merensky Reef. The results have shown that the divalent cation, Ca2+, resulted in higher %Cu and %Ni recoveries at all collector mixtures compared to the monovalent cation, Na+. The concentrate grades were, however, slightly compromised, as slightly more gangue reported to the concentrate in the presence of Ca2+. This behavior is attributed to the effect of polyvalent cations on bubble coalescence and froth stability.

scholarly journals Low-grade serous epithelial ovarian cancer: a comprehensive review and update for radiologists

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sofia Amante ◽  
Filipa Santos ◽  
Teresa Margarida Cunha
Keyword(s):  
Ovarian Cancer ◽  
Serous Carcinoma ◽  
Low Grade ◽  
Resonance Imaging ◽  
Clinicopathologic Characteristics ◽  
Borderline Tumour ◽  
Molecular Features ◽  
Serous Epithelial Ovarian Cancer ◽  
The Difference

AbstractLow-grade serous carcinoma (LGSC) is an infrequent subtype of ovarian cancer, corresponding to 5% of epithelial neoplasms. This subtype of ovarian carcinoma characteristically has molecular features, pathogenesis, clinical behaviour, sensitivity to chemotherapy, and prognosis distinct to high-grade serous carcinoma (HGSC). Knowing the difference between LGSC and other ovarian serous tumours is vital to guide clinical management, which currently is only possible histologically. However, imaging can provide several clues that allow differentiating LGSC from other tumours and enable precise staging and follow-up of ovarian cancer treatment. Characteristically, LGSC appears as mixed lesions with variable papillary projections and solid components, usually in different proportions from those detected in serous borderline tumour and HGSC. Calcified extracellular bodies, known as psammoma bodies, are also a common feature of LGSC, frequently detectable within lymphadenopathies and metastases associated with this type of tumour. In addition, the characterisation of magnetic resonance imaging enhancement also plays an essential role in calculating the probability of malignancy of these lesions. As such, in this review, we discuss and update the distinct radiological modalities features and the clinicopathologic characteristics of LGSC to allow radiologists to be familiarised with them and to narrow the differential diagnosis when facing this type of tumour.

Insights into Heap Bioleaching at the Agglomerate-Scale

2017 ◽  
Vol 262 ◽  
pp. 185-188 ◽  
Author(s):  
Alison Cox ◽  
Christopher G. Bryan
Keyword(s):  
Interstitial Cell ◽  
Cell Concentration ◽  
Low Grade ◽  
Dissolved Metals ◽  
Copper Ore ◽  
Cell Numbers ◽  
Liquid Phases ◽  
Heap Bioleaching ◽  
Cell Concentrations ◽  
The Difference

Previous agglomerate-scale heap bioleaching studies have outlined the variations in cell numbers of the liquid and attached phases during colonisation of sterilised ore by a pure culture. In this study, a mixed mesophilic culture was used in agglomerate-scale columns containing non-sterilised low-grade copper ore. Over a six - month period, columns were harvested at various intervals to provide snapshots of the metal distribution and the quantity, location, and ecological variations of mineral-oxidizing microbes within the ore bed. The initial colonisation period in this experiment was dissimilar to previous work, as the indigenous community was retained within the ore-bed throughout acid agglomeration. The overall colonisation phase lasted for approximately 1,000 hours until cell concentrations stabilised. In each column, less than 0.05% of the total cells were found in the leachate, 15-20% in the interstitial phase and the remaining ~80% were attached to the mineral surface. Once cell numbers had stabilised, interstitial cell concentrations were approximately 2,000× greater than those in the leachate. This difference persisted for the duration of the experiment. Copper concentrations in the two liquid phases generally decreased over time, but were on average 50× higher in the interstitial phase. Iron concentrations were more stable, but again were 30× higher in the interstitial phase. This demonstrates that that the difference in cell concentration between the leachate and interstitial phases cannot be explained through diffusion gradients within the system as it is much greater than those observed for the dissolved metals. It also shows that the specific environmental conditions of the interstitial and attached cells are very different to those inferred through analysis of leachates alone.

Soil stripping and replacement for the rehabilitation of bauxite-mined land at Weipa. I. Initial changes to soil organic matter and related parameters

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 345 ◽  
Author(s):  
G. D. Schwenke ◽  
D. R. Mulligan ◽  
L. C. Bell
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Field Experiments ◽  
Surface Soil ◽  
Soil Disturbance ◽  
Microbial Biomass C ◽  
Low Grade ◽  
Double Pass ◽  
Organic C ◽  
The Difference

At Weipa, in Queensland, Australia, sown tree and shrub species sometimes fail to establish on bauxite-mined land, possibly because surface-soil organic matter declines during soil stripping and replacement. We devised 2 field experiments to investigate the links between soil rehabilitation operations, organic matter decline, and revegetation failure. Experiment 1 compared two routinely practiced operations, dual-strip (DS) and stockpile soil, with double-pass (DP), an alternative method, and subsoil only, an occasional result of the DS operation. Other treatments included variations in stripping-time, ripping-time, fertiliser rate, and cultivation. Dilution of topsoil with subsoil, low-grade bauxite, and ironstone accounted for the 46% decline of surface-soil (0–10 cm) organic C in DS compared with pre-strip soil. In contrast, organic C in the surface-soil (0–10 cm) of DP plots (25.0 t/ha) closely resembled the pre-strip area (28.6 t/ha). However, profile (0–60 cm) organic C did not differ between DS (91.5 t/ha), DP (107 t/ha), and pre-strip soil (89.9 t/ha). Eighteen months after plots were sown with native vegetation, surface-soil (0–10 cm) organic C had declined by an average of 9% across all plots. In Experiment 2, we measured the potential for post-rehabilitation decline of organic matter in hand-stripped and replaced soil columns that simulated the DS operation. Soils were incubated in situ without organic inputs. After 1 year’s incubation, organic C had declined by up to 26% and microbial biomass C by up to 61%. The difference in organic C decline between vegetated replaced soils (Expt 1) and bare replaced soils (Expt 2) showed that organic inputs affect levels of organic matter more than soil disturbance. Where topsoil was replaced at the top of the profile (DP) and not ploughed, inputs from volunteer native grasses balanced oxidation losses and organic C levels did not decline.

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