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−

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.

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

Molecules ◽

10.3390/molecules26175365 ◽

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.

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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

Environmental Sciences Proceedings ◽

10.3390/iecms2021-10632 ◽

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.

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Study of Low-Grade Nickel Laterite Processing Using Palm Shell Charcoal as Reductant

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1000.436 ◽

2020 ◽

Vol 1000 ◽

pp. 436-446

Author(s):

Bambang Suharno ◽

Nolzha Primadha Ilman ◽

Achmad Shofi ◽

Deni Ferdian ◽

Fajar Nurjaman

Keyword(s):

Sodium Sulfate ◽

Selective Reduction ◽

Reduction Process ◽

Low Grade ◽

X Ray Diffraction ◽

X Ray ◽

Palm Shell ◽

Higher Temperature ◽

Nickel Grade

This study was conducted to investigate the effect of palm shell charcoal reductant in the selective reduction of nickel ore with the addition of additive at various temperatures and times. In this present work, 10 wt. % of sodium sulfate as additive and 5, 10, 15 wt. % of palm shell charcoal as reductants were used. The reduction of nickel ore was performed at 950oC, 1050oC, and 1150oC for 60, 90, and 120 minutes. A wet magnetic separation method was then carried out to separate the concentrates and tailings. Characterization of reduced ore was performed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), while the composition of ferronickel in concentrate was identified by X-Ray Fluorescence (XRF). The result showed that the higher temperature reduction, the higher of nickel grade, and its recovery at the concentrate. Nevertheless, the longer reduction time and the more reductant in nickel ore lowering the nickel grade and its recovery in the concentrate. The optimum condition in this selective reduction process was obtained with the addition of 5 wt. % of reductant and 10 wt. % of sodium sulfate in nickel ore, which was reduced at 1150oC for 60 minutes. It resulted in 4.60% and 73.23% for nickel grade and its recovery, respectively.

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Impact of Sodium Hexametaphosphate on the Flotation of Ultrafine Magnesite from Dolomite-Rich Desliming Tailings

Minerals ◽

10.3390/min11050499 ◽

2021 ◽

Vol 11 (5) ◽

pp. 499

Author(s):

Duong Huu Hoang ◽

Doreen Ebert ◽

Robert Möckel ◽

Martin Rudolph

Keyword(s):

Ultrafine Particles ◽

Raw Materials ◽

Low Cost ◽

Froth Flotation ◽

Open Circuit ◽

Ore Deposits ◽

Sodium Hexametaphosphate ◽

Low Grade ◽

Low Contrast ◽

The Impact

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from desliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on the following: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite, and (iii) its effect on the entrainment. As a depressant/dispersant, SHMP has a beneficial impact on the flotation separation between magnesite and dolomite. However, there is a trade-off between grade and recovery, and as well as the dewatering process which needs to be considered. When the SHMP increases from 200 g/t to 700 g/t, the magnesite grade increases from 67% to 77%, while recovery decreases massively, from 80% to 40%. The open circuit with four cleaning stages obtained a concentrate assaying 77.5% magnesite at a recovery of 45.5%. The dolomite content in the concentrate is about 20%, where 80% of dolomite was removed and importantly 98% of the quartz was removed, with only 0.3% of the quartz in the final concentrate. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) as a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. Using only 350 g/t of HEDP can achieve a similar grade (76.3%), like 700 g/t of SHMP (76.9%), while obtaining a 17% higher magnesite recovery as compared to 700 g/t of SHMP. Interestingly, the proportion of hydrophilic quartz minerals ending up in the concentrate is lower for HEDP, with only 1.9% quartz at a recovery of 21.5% compared to the 2.7% of quartz at a recovery of 24.9% when using SHMP. The paper contributes in general to understanding the complexity of the depressant responses in froth flotation.

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Stimulation of Plasma Thyroxine Levels by Novel Water Chemistry during Smoltification in Chinook Salmon (Oncorhynchus tshawytscha)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-169 ◽

1990 ◽

Vol 47 (8) ◽

pp. 1513-1517 ◽

Cited By ~ 23

Author(s):

Timothy L. Hoffnagle ◽

Albert J. Fivizzani

Keyword(s):

Water Chemistry ◽

Flow Rate ◽

Chinook Salmon ◽

Oncorhynchus Tshawytscha ◽

Water Source ◽

Control Fish ◽

Exposed Fish ◽

Freshwater Population ◽

Artificial Photoperiod ◽

Stimulation Of

The separate influences of changes in water chemistry and flow rate on plasma thyroxine levels were assessed in a freshwater population of chinook salmon (Oncorhynchus tshawytscha) undergoing smoltification. Fish subjected to a change in water source had plasma thyroxine levels significantly greater than those of controls on several sampling dates. Maximum levels were observed 10 d after water change. Conversely, plasma thyroxine levels in fish for which the flow rate was increased showed little change and were never significantly different from controls. Plasma thyroxine levels were greater in fish held under a natural rather than artificial photoperiod but the patterns of change were similar in the two groups. Control fish transported to a new hatchery and novel water source attained plasma thyroxine levels which were even greater than those of novel water-exposed fish at the original hatchery. The results indicated that altered water chemistry rather than increased flow rate was the stimulus for the elevation in plasma thyroxine levels associated with smoltification in these chinook salmon.

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