Flotation Results Research Articles

The role of sodium metabisulphite in depressing pyrite in chalcopyrite flotation using saline water

In response to the high pyrite recovery in copper flotation using seawater, this study investigated the role of sodium metabisulphite (MBS), a widely used pyrite depressant, in depressing the flotation of copper-activated pyrite to identify a solution to maximising pyrite rejection. It started with chalcopyrite flotation against pyrite with MBS added in the mill before grinding and in the conditioning cell before flotation. The surface properties of pyrite exposed to different reagent schemes were investigated by X-ray photoelectron spectroscopy (XPS) analysis. The reactions on pyrite surface responsible for different flotation results were then investigated by cyclic voltammogram (CV) measurements and discussed in terms of a radical chain mechanism involving the redox cycling of Cu(I/II) induced by sulphite species. It was found that the addition of MBS during the conditioning stage was more efficient in depressing the flotation of copper-activated pyrite. This is because the combination of sulphite ions and oxygen may form a strongly oxidising radical SO5·- which can oxidise Cu(I)S, the copper activation product on pyrite surface, to form hydrophilic Cu(OH)2/CuSO4. The addition of MBS at low dosages in the mill depressed pyrite flotation to a less extent due to the less oxygen available, while its depression effect was even weakened at high dosages due to the consumption of dissolved oxygen and a strongly reducing environment which favoured copper activation on pyrite surface.

Selective flotation of chalcopyrite from pyrite using diphosphonic acid as collector

Ethyl xanthate (EX) is a widely used collector in the flotation of sulfide minerals. However, it also has the disadvantages of low selectivity and harm to human health. Screening and/or designing more selective and green collectors is a ‘hot topic’ in mineral processing field. In this work, 1-Hydroxyethylidene-1, 1-diphosphonic acid (HEDP), a cheap green reagent widely used in water treatment, was for the first time, applied in the flotation separation of chalcopyrite from pyrite. In addition, a comparative test of the traditional EX collector was also carried out. Flotation results of single mineral and binary mineral mixture showed that HEDP possessed a better selectivity for the separation of chalcopyrite from pyrite than EX. Zeta potential measurement results indicated that HEDP exhibited a stronger adsorption on chalcopyrite and a weaker interaction with pyrite. Hence, HEDP is a promising collector that possesses the potential to replace EX in future chalcopyrite flotation practice.

Molecular-level insights into the adsorption of a hydroxy-containing tertiary amine collector on the surface of magnesite ore

A molecular dynamics simulation was used to investigate the adsorption performance and mechanism of a tertiary amine surfactant and the surface of magnesite ore in aqueous solution at the molecular level. The molecular dynamics simulation results revealed distinct differences among the adsorption performances to quartz, magnesite, and dolomite with bis(2-hydroxyethyl)dodecylamine (BHDA) (quartz > dolomite > magnesite). The results of adsorption tests, flotation, and zeta potential measurements confirmed the same tendencies in the adsorption behaviors. The differences in flotation behavior could be ascribed to electrostatic attraction and hydrogen bonding. Property analyses showed that hydrogen bonding played a considerable role in the adsorption process of BHDA. The introduction of multiple hydroxyl groups improved the water solubility of BHDA and enhanced its adsorption on mineral surfaces containing exposed O atoms. The higher flotation selectivity of BHDA compared to dodecylamine (DDA) was attributed to the relatively weaker electronegativity and the stronger steric hindrance of BHDA.

First report of Echinococcus multilocularis in cats in Poland: a monitoring study in cats and dogs from a rural area and animal shelter in a highly endemic region

BackgroundAlveolar echinococcosis is a dangerous zoonotic disease caused by larval forms of Echinococcus multilocularis. In its life-cycle, the principal definitive host is the red fox; however, domesticated carnivorous animals (dogs and cats) can also act as definitive hosts. Until now, there were no data concerning this infection in cats in Poland. The aim of this study was to estimate the prevalence of E. multilocularis in cats and dogs originating from rural areas and animal shelters in a region characterised by a high prevalence of E. multilocularis in red foxes.MethodsSamples of faeces were collected from 67 cats and 268 dogs from a rural area (villages and animal shelters) of a highly endemic region in southeastern Poland. Samples were examined using nested PCR (E. multilocularis), multiplex PCR (E. multilocularis, Taenia spp.) and PCR [E. granulosus (s.l.)]. Additionally, faeces were examined microscopically (flotation). Moreover, intestines from 110 red foxes shot in the investigated area were examined (sedimentation and counting technique).ResultsPositive PCR results for E. multilocularis were obtained in 4 cats (6.0%) and 4 dogs (1.5%). There were no significant differences between groups of animals (from a shelter and with an owner) concerning the prevalence of E. multilocularis in both cats and dogs. Taenia spp. were found in 10 cats (14.9%) (Taenia taeniaeformis and T. hydatigena) and 26 dogs (9.7%) (T. hydatigena, T. serialis, T. taeniaeformis, T. crassiceps, T. pisiformis and T. ovis) and Mesocestoides litteratus was found in 4 cats (6.0%) and 3 dogs (1.1%). All samples were negative for E. granulosus by PCR. Taking into consideration PCR and flotation results, 29 cats (43.3%) and 73 dogs (27.2%) were infected with helminths (26.9 and 11.9%, respectively, were infected with tapeworms). The highly endemic status of the investigated area was confirmed by examination of red foxes: 48.2% of examined red foxes were infected with E. multilocularis.ConclusionsTo the best of our knowledge, this study reports the presence of E. multilocularis in cats for the first time in Poland and confirms the role of dogs in this infection in highly endemic areas.

Gutter oil, an alternative collector to traditional diesel collector for cleaner flotation of fine coal

ABSTRACT In order to realize cleaner production of coal flotation and reduce the dependence of traditional nonrenewable diesel collector, renewable collector was prepared from gutter oil and used for the flotation process. For contrast, flotation performance of gutter oil and traditional diesel collector was analyzed. The functional group composition of the two collectors was compared by infrared spectrum analysis (FTIR). In addition, the adsorption properties of collectors on the particle surface were analyzed by X-ray photoelectron spectroscopy (XPS). Then, flotation experiments were conducted to verify the applicability of renewable collector. FTIR results show that the main functional groups of diesel oil are C-C and C-H, while the gutter oil contains C = O and C-O besides hydrophobic groups, which results in higher ash content of clean coal. XPS results show that the hydrophobicity group content of coal increased significantly after the adsorption of collector. The flotation result show that the ash content of clean coal can be reduced to less than 10% and accompanied by more than 80% combustible matter recovery for both the gutter oil and diesel oil. This study demonstrates that the coal flotation process can become cleaner by using gutter oil as green collector.

Separation performance of mechanical flotation cell and cyclonic microbubble flotation column: in terms of the beneficiation of high-ash coal fines

ABSTRACT Separation performance of mechanical flotation cell and cyclonic microbubble flotation column (FCMC) was compared in terms of the beneficiation of high-ash coal fines that has the characteristics of the content of <0.045 mm accounting for more than 50% of the flotation feed and the ash content of <0.045 mm being more than 50%. The optimal experimental results of the mechanical flotation were determined as the flotation perfection index η of 47.37%, the clean coal yield of 39.19% and the clean coal ash content of 10.78% at the feed pulp concentration of 40 g/L through twice explorative flotation experiments and the orthogonal experiment. It was found that the ash content of the clean coal had a strong dependence on the feed concentration. In contrast, the yield of the concentrate of the column flotation was increased to 43.26% with the lower ash content of 9.47% and the higher η of 54.51% even at higher feed concentration of 60 g/L. The remarkable separation efficient of the FCMC flotation column for the difficult-to-float coal slime that has the characteristics of high content of fine particles with high ash was attributed to the presence of the centrifugal force field, more microbubbles generated by hydrodynamic cavitation, the form of countercurrent mineralization, and thicker froth layer.

Influence of pickling on the surface composition and flotability of Daliuta long-flame coal

Surface modification for low-rank coal with poor hydrophobicity is critical to its efficient flotation. In the present study, induction time and flotation results were employed to evaluate the coal sample's flotability in the pickling process, while the changes in coal surface properties were comprehensively investigated by various surface analysis technologies. The results suggested that the induction time between coal particles and bubbles decreased from 115 ms to 13 ms with increases in the concentration of hydrochloric acid, and the combustible matter recovery correspondingly exhibited an evident increase from 31.98 to 59.22%. Additionally, after pickling, a significant increase in the liberation of gangue minerals from coal particles was observed by XRD and SEM measurements. Furthermore, the XPS results indicated that the hydrophilic oxygen-containing functional groups of coal sample decreased after the pickling process. Consequently, the enhanced flotation performance could be attributed to the changes in surface chemical functional groups and increased liberation of gangue minerals from coal particles in the pickling process.

Coproantigen Detection Augments Diagnosis of Common Nematode Infections in Dogs

Microscopic methods which employ active or passive flotation have been used to detect parasite diagnostic stages in the feces of companion animals for many years. More recently, coproantigen ELISAs for the detection of excretory/secretory products from intestinal nematodes have been introduced. These assays can identify the presence of parasites when eggs are not recovered by flotation (e.g. prepatent infection or intermittent egg shedding). The study was designed to assess the added benefit of these coproantigen tests in canine fecal diagnostics. The work was performed at 3 separate sites where canine fecal samples were each independently evaluated by both centrifugal flotation with an expert examiner (CFE) and passive flotation with a less experienced examiner. All samples were also tested using coproantigen ELISA to detect ascarid, hookworm, or whipworm antigen (IDEXX Laboratories, Inc, Westbrook, Maine). A total of 1202 samples were collected; 626 were from shelter dogs and 576 were from pet dogs. CFE recovered ascarid eggs in 58 samples, hookworm eggs in 229 samples, and whipworm eggs in 95 samples. Of the positive samples identified by CFE, the PFE and ELISA identified 40 and 51 ascarid samples, 188 and 203 hookworm samples, and 65 and 67 whipworm positive samples, respectively. The coproantigen ELISA identified 8 ascarid, 82 hookworm, and 22 whipworm positive samples that were not detected by CFE. The combined results of passive flotation and the coproantigen ELISA improved the percent agreement with centrifugal flotation, suggesting that greater sensitivity of detection may be achieved through the use of complementary diagnostic methods. However, errors of misidentification and poor recovery apparently introduced by less experienced examiners using an inferior flotation method remained. A diagnostic approach that combines coproantigen assays with centrifugal flotation and examination by an expert allows detection of more ascarid, hookworm, and whipworm infections.

Flotation Behavior, Collector Adsorption Mechanism of Quartz and Feldspar-Quartz Systems Using PEA as a Novel Green Collector

A novel green cationic surfactant Poly (propylene glycol) bis (2-aminopropyl ether) (PEA) with multiple amine groups was utilized as a collector for flotation separation of quartz from feldspar-quartz associated ore (FQA) without acid (particularly, HF) and alkali. The collecting performances and the adsorption mechanisms of PEA on the quartz/FQA were investigated through flotation experiments, ICP-OES, XRD, Zeta potential, FTIR and XPS measurements. A remarkable separation of the quartz from FQA has been realized in an environmental friendly way. The froth flotation results show that the flotation recovery of quartz is 97.79% and that of FQA is 19.30% at pH 9.00–9.50 with 10−4 M PEA when the particle size ranges from 150 to 270 μm. The results of batch flotation, ICP-OES and XRD analyses show that the first flotation product is almost quartz, while more feldspar and little quartz exist in the sink product when compared with the FQA feed. The mechanism of PEA acting as the collector for the separation of quartz/feldspar has been investigated. The PEA is adsorbed on the quartz surface by electrostatic and hydrogen bonding interaction with ─NH3+ /─NH2 head groups, while is less adsorbed on the feldspar surface due to electrostatic repulsion between the K+ / Na+ ions and the positively charged ─NH3+/─NH2 head groups of PEA. A conceptual adsorption model of the PEA cationic collector on the quartz and the FQA surfaces has been proposed.

Utilization of a new Gemini surfactant as the collector for the reverse froth flotation of phosphate ore in sustainable production of phosphate fertilizer

An effective collector plays a vital role in the reverse flotation of phosphate ore as well as sustainable production of phosphate fertilizer. Phosphate fertilizer is used to achieve the sustainable increase in the production of food. Phosphate ore is concentrated by reverse froth flotation and used as a raw material to produce phosphate fertilizer in industry. However, all the surfactants used in the phosphate ore reverse flotation process are conventional monomeric surfactants contain a single similar hydrophobic group in the molecule, which results in a low production efficiency and severe environmental contamination. In this work, a novel Gemini surfactant, N,N′-bis(dodecyldimethyl)-1,4-butane diammonium dibromide (BDBD) was prepared, and originally recommended as a collector for reverse froth flotation separation of silicoide from phosphate ore. The performance of BDBD was compared with the results acquired using its conventional monomeric surfactant dodecylamine hydrochloride (DAH). The bench-scale flotation results showed that BDBD had excellent collecting power for silicoide and significant selectivity against apatite at pH 9. Moreover, BDBD presented stronger desilication efficiency than DAH. Achieving the superior flotation performance (P2O5 recovery increased by 2.41%, P2O5 content increased by 0.26%, and SiO2 content reduced by 2.52%), the dosage of Gemini type BDBD collector (100 g/t) is four times less than that of monomeric DAH collector (400 g/t). Therefore, this work provides a promising approach to the sustainable phosphate fertilizer production and to address global food security concerns.

Flotation separation of Cu-Mo sulfides by O-Carboxymethyl chitosan

The flotation separation of molybdenite from copper sulfide minerals (mostly chalcopyrite) typically relies on the use of toxic inorganic depressants such as cyanides and sodium sulfide/hydrosulfide. In this work, a nontoxic, biodegradable and cost-effective derivative of the natural polysaccharide chitosan, O-Carboxymethyl chitosan (O-CMC), is investigated as an alternative depressant for molybdenite during the Cu-Mo separation. The flotation tests on single minerals showed that O-CMC strongly depresses molybdenite flotation from pH 3–11, while chalcopyrite flotation is not affected by O-CMC except at pH 3. The flotation tests on mineral mixtures confirmed O-CMC could efficiently depress the molybdenite flotation without dramatically reducing chalcopyrite recovery and selective separation of molybdenite and chalcopyrite was achieved over the entire pH range tested from pH 3 to pH 11. To explain the flotation results, the adsorption characteristics of O-CMC on both minerals were investigated by atomic force microscopy (AFM) imaging. The experimental results indicate that the strong adsorption of O-CMC onto molybdenite surface over the chalcopyrite surface is responsible for the selective separation.

Flotacijska ispitivanja majdanpečke rude bakra u cilju poboljšanja iskorišćenja bakra i kvaliteta koncentrata primenom različitih kolektora

This paper presents the results of mineralogical and flotation studies on the copper ore from the deposit North Revir in the Copper Mine Majdanpek, using different collectors. XRD and ore mineralogical analysis showed that the most common minerals are pyrite and chalcopyrite. Chemical analysis confirm that it is a complex low-grade copper ore with average copper content of 0,273%. The content of precious metals (Au and Ag) was 0.2 g/t and 1.2 g/t, respectively. The main aim of flotation studies have been the effect of collector type on the recovery and concentrate grade in the copper flotation process. Various collectors and combinations of them were used in the rough flotation tests of copper ore. The copper recovery was in the range from 79.43% (test no. 4) to 84.96% (test no. 7). The best flotation results were obtained with mixture collectors of sodium isopropyl xanthate (Z11), dialkyl dithiophosphinates (Aerophine 3404) and SKIK BZ 2000. The collector's dosages of 20 g/t Z11, 8 g/t AP3404 and 8 g/t SKIK BZ 2000 produced the copper recovery (84.96 %) with copper concentrate grade of 1.52% .

РЕЗУЛЬТАТЫ ФЛОТАЦИИ ЗОЛОТОСОДЕРЖАЩЕЙ МЕДНО-ПОРФИРОВОЙ РУДЫ

РЕЗУЛЬТАТЫ ФЛОТАЦИИ ЗОЛОТОСОДЕРЖАЩЕЙ МЕДНО-ПОРФИРОВОЙ РУДЫ

Gemini surfactant: A novel flotation collector for harvesting of microalgae by froth flotation

Froth flotation has been proved to be a promising approach for commercial scale harvesting of microalgae. However, all the surfactants used in the microalgae flotation harvesting process are conventional monomeric surfactants contain a single similar hydrophobic group in the molecule, which results in a low harvesting efficiency. In this work, a novel Gemini surfactant, N,N′-bis(cetyldimethyl)-1,4-butane diammonium dibromide (BCBD) was prepared, and originally recommended as a collector for froth flotation harvesting of Chlorella vulgaris from culture medium. The performance of BCBD was compared with the results acquired using its conventional monomeric surfactant cetyl trimethyl ammonium bromide (CTAB). The bench-scale flotation results showed that BCBD had excellent collecting power for Chlorella vulgaris. Achieving the obviously superior flotation harvesting performance (flotation recovery increased by 21.4% and enrichment ratio increased by 22.9), the dosage of Gemini type BCBD collector is five times less than that of monomeric CTAB collector.

Analysis of kinetic models for chalcopyrite flotation: effect of operating parameters

ABSTRACTIn this research, the influence of pH, particle size, the type of collector and frother and their concentration was studied on the flotation kinetic parameters, rate constant and ultimate recovery. In this regard, three different kinetic flotation models such as Classical model, Klimpel model, and fully mixed reactor model were applied to evaluate the batch flotation results. The results showed that the fully mixed reactor model gave the best fit to the experimental data. In the second stage, variation of flotation rate constants and ultimate recoveries are investigated with respect to particle size and chemical conditions. It was found that the rate constant (k) and ultimate recovery () were strongly dependent on pH and types of collector and their frother and dosages. It was also observed that best values of , K, separation efficiency, and selectivity index are obtained in the presence of a mixture of isopropyl-n-ethyl thionocarbamate (C4132) and Flomin C7240 (a mixture of 10–20 wt% sodium alkyl dithiophosphate and 20–30 wt% sodium mercaptobenzothiozole) as the collector and a mixture of polypropylene glycol (A65) and methyl isobutyl carbinol as the frother and dosages of 40 g/ton for both reagents, respectively.

Flotation separation of pyrite from arsenopyrite in the presence of oxidants

ABSTRACTFour oxidants, NaClO, KMnO4, K2Cr2O7, and H2O2, were used to promote the flotation separation of pyrite (FeS2) from arsenopyrite (FeAsS). Ore flotation results indicate that H2O2 has the best selectivity for the As-S separation. When H2O2 is used, the As content in pyrite concentrate decreases from 2.27% without addition of H2O2 to 1.11% with H2O2 dosage of 900 g/t, and the pyrite recovery is still high (86.58%). NaClO, KMnO4, and K2Cr2O7 have poor selectivity for the As-S separation. Cyclic voltammetry measurements by using mineral microelectrodes indicate that H2O2 shows selective oxidation effect on arsenopyrite while other three oxidants have no selective oxidation effects on arsenopyrite and pyrite. In the presence of dixanthogen coating on the mineral surface, all the four kinds of oxidants can oxidize dixanthogen to a certain degree. Moreover, the collector coatings on arsenopyrite surface are oxidized more easily than on pyrite.

Flotation of coarse and fine pyrochlore using octyl hydroxamic acid and sodium oleate

The flotation of pyrochlore using two common oxide collectors, octyl hydroxamic acid (OHA) and sodium oleate (NaOl), was studied by microflotation tests on high purity pyrochlore sample and batch flotation tests on a pyrochlore ore sample. The high purity pyrochlore sample was screened into different size fractions, −20 µm, −38 + 20 µm, −75 + 38 µm, −125 + 75 µm, and +125 µm and used in separate microflotation tests. The pyrochlore ore sample was floated as a whole in batch flotation but the flotation concentrate as well as the feed were screened into −20 µm, −38 + 20 µm, −75 + 38 µm, and −150 +75 µm to find the grade and recovery in each size fraction. The microflotation showed that under the same pH and collector concentration, OHA floated the −20 µm and −38 + 20 µm pyrochlore more strongly than NaOl. This phenomenon was also observed in batch flotation of the pyrochlore ore sample, where under the same pH and collector dosage either weight based (g/t) or molar based (mol/t), the OHA recovered pyrochlore from the −20 µm size fraction with higher enrichment ratio and higher mass pull than NaOl. The adsorption of NaOl and OHA on the pyrochlore surface was examined by Fourier transform infrared spectroscopy (FTIR), zeta potential and X-ray photoelectron spectroscopy (XPS) analyses. FTIR and zeta potential measurements indicated that both collectors adsorbed on pyrochlore through chemisorption followed by physisorption, and XPS electron binding energy and depth profile analyses showed that the OHA may have a stronger chemical affinity to pyrochlore than NaOl, contributing to the stronger chemisorption. The different adsorption mechanisms were linked to the flotation results, pointing to the role of chemisorption strength on fine particle flotation recovery.

Determination of surface chemistry and flotation properties of rare earth mineral allanite

In this study, flotation properties of allanite, a sorosilicate rare earth mineral that commonly found in some new complex ore reserves, was studied with EDA (CH3–(CH2)9–O–(CH2)3–NH2/ethylenediamine), a commercial cationic collector in the etheramine acetate group, and R845N (tetrasodium N-(1,2-dicarboxyethyl-N-octadecyl/octadecenyl sulfosuccinamate), a commercial anionic collector in the alkyl succinamate group. In this context, firstly micro-flotation studies were carried out using a pure crystalline allanite specimen. In accordance with micro-flotation studies; zeta potential, contact angle, and bubble-particle attachment time measurements were also carried out to investigate the surface properties of allanite mineral. Conventional flotation experiments were also carried out under the conditions determined in the surface chemistry studies. The micro-flotation experiments showed that the flotation recovery increased up to approximately 93.00% and 48.50% at 100 ppm for EDA and R845N, respectively. A strong relationship between flotation recovery and bubble-particle attachment time were observed. The zeta potential and contact angle values of the allanite sample increased with the increasing concentrations for both collectors which indicated a successful collector adsorption onto allanite surface. Moreover, a correlation between the results of flotation recovery, contact angle and zeta potential measurements was also determined. Thus, a significant contribution was achieved in terms of understanding the micro-flotation results. The results of conventional flotation were consistent with the micro-flotation results as the ΣREE grade of the floated fractions were 0.59% and 0.99%, and the recovery rate of floating fractions were 81.39% and 64.24% for EDA and R845N, respectively. The obtained results clearly demonstrated that R845N, a collector of the alkyl succinamate class, can be used for selective separation of allanite from the other silicate gangue minerals.

Flotation of sylvite from potash ore by using the Gemini surfactant as a novel flotation collector

Potash fertilizer ensures the necessary agricultural yields to feed an increasing world population. Over 80% of the world’s potash fertilizer is produced by the selective froth flotation of KCl (sylvite) from NaCl (halite). However, all the surfactants used in the potash froth flotation process are traditional monomeric surfactants contain a single similar hydrophobic group in the molecule, which leads to a low production efficiency. In this work, a novel Gemini surfactant, N,N'-bis (octadecyldimethyl)-1,4-butane diammonium dibromide (BOBD) was prepared, and originally recommended as a collector for froth flotation separation of sylvite from halite for potash ore. The performance of BOBD was compared with the results acquired using its traditional monomeric surfactant octadecylamine hydrochloride (OAH). The bench-scale flotation results showed that BOBD had excellent collecting power for sylvite and significant selectivity against halite at natural pH. Moreover, BOBD presented stronger desalination efficiency than OAH. The results gained with the Gemini collector were better in terms of KCl recovery and NaCl content than those gained with four times higher dosages of the conventional monomeric surfactant.

Application of gaseous pyrolysis products of the waste cooking oil as coal flotation collector

Fossil fuel depletion, environmental concerns, and steep hikes in the price of fossil fuels make it imperative to develop alternative and renewable products to decrease oil products consumption in coal flotation process. Pyrolysis product of the waste cooking oil was proposed as a potential coal flotation collector in this paper. The gas chromatograph-mass spectrometer test and thermogravimetric method were used to study the properties of the waste cooking oil. The pyrolysis product of the waste cooking oil was used as coal flotation collector in two different ways. Thermogravimetric analysis showed that the pyrolysis of the waste cooking oil sample was mainly divided into three processes. The waste cooking oil pyrolysis product possessed strong collecting ability and better selectivity, and can replace diesel as a coal flotation collector. 79% combustible matter recovery was obtained in the presence of 1 kg/Mg DW-450 °C dosage compared with that of 68% in the presence of diesel. Better flotation results can be obtained in the presence of gaseous pyrolysis products of the waste cooking oil. With the increase of pyrolysis temperature of the waste cooking oil, the combustible matter recovery of the concentrate is increasing, while the ash content of the concentrate is showing a decreasing trend.