Flotation Separation Of Pyrite Research Articles

Flotation separation of pyrite and carbonate minerals from a carlin-type gold deposit in Guizhou by a new combined collector and its adsorption mechanism

Flotation separation of pyrite and carbonate minerals from a carlin-type gold deposit in Guizhou by a new combined collector and its adsorption mechanism

Flotation separation of pyrite and chalcopyrite with potassium permanganate as a depressant

Flotation separation of pyrite and chalcopyrite with potassium permanganate as a depressant

Flotation separation of pyrite from chalcopyrite by tetrazinan-thione collectors

Flotation separation of pyrite from chalcopyrite by tetrazinan-thione collectors

Flotation separation of pyrite from arsenopyrite by surface discharge plasma modification

Low-temperature plasma has not been reported to be applied to pulp system although it has been proved to be an effective method for the selective modification of minerals. In this research, surface dielectric barrier discharge (SDBD) low-temperature plasma was introduced into the pulp through a bubble generator, and its modification mechanism on arsenopyrite and pyrite was investigated. SDBD plasma exhibited an excellent selectivity where the concentration of hydrophilic oxidation products on the surface of plasma-modified pyrite was much less than arsenopyrite. The introduction of plasma into the pulp resulted in a longer residence time of the pulp chemistry of arsenopyrite in the stable oxidation region than that of pyrite. Plasma modification significantly enhanced the oxidation degree of the defect area on the surface of arsenopyrite, which resulted in the decrease of its hydrophobicity and thereby hindered the adsorption of collector and the oxidation of xanthate ions into dixanthogen. Since its environmently-friendly property, SDBD plasma modification has a broad application prospect in the flotation separation of polymetallic sulfide ores.

Studies on the selective flotation of pyrite from fine serpentine by using citric acid as depressant

Fine serpentine can form slimes coating on sulfide surface, which worsens sulfide flotation. To solve this problem, in this study, the effect of citric acid (CA) on the flotation separation of pyrite from serpentine and its mechanisms were systematically investigated. Micro-flotation results showed that the serpentine with −10 µm fraction had a significant depression effect on pyrite flotation. However, the utilization of CA could efficiently limit the adverse effect of serpentine on pyrite flotation with an increase of pyrite recovery from 16% to 95%. The results of adsorption, Fourier transform infrared spectrometry (FTIR), and X-ray photoelectron spectroscopy (XPS) indicated that CA could adsorb on serpentine surface, which might be caused by the chelation between the carboxyl groups in CA and the magnesium species on serpentine surface. Besides, the results of inductively coupled plasma-optical emission spectroscopy (ICP-OES) showed that the introduce of CA also accelerated the dissolution of magnesium cations on serpentine surface. In this way, the surface charge of serpentine was converted from positive to negative after interacting with CA, and the hetero-coagulation between serpentine and pyrite was broken, which was further verified by turbidity results. Therefore, the floatability of pyrite was restored. Based on these findings, CA is likely to act as an effective depressant in the flotation separation of sulfide ore from serpentine.

Selective adsorption behavior and mechanism of a high-performance depressant in the flotation separation of pyrite from talcum

Galactomannan (GM) was used as depressant to facilitate the separation of pyrite from talcum. Compared with common depressant dextrin, GM not only possessed higher selectivity, but also GM was consumed approximately 87% lower than that of dextrin at the optimal separation point. The recovery of pyrite and talcum was 83.52% and 26.73% respectively with pH 4.7 and GM dosage of 40 mg/L, at which the pyrite could be effectively separated from talcum. However, the recovery of pyrite and talcum was 68.34% and 33.45% respectively with pH 4.3 and dextrin dosage of 300 mg/L. The selective depression mechanism of GM on talcum was investigated by Fourier transform infrared spectroscopy (FT-IR), zeta potential measurements, X-ray photoelectron sspectroscopy (XPS) and interaction energy calculation. It was found that the GM was adsorbed on pyrite through physisorption, however it was adsorbed on talcum by chemisorption. Mg was the main active site of talcum to react with GM. Since SBX (sodium butyl xanthate) was adsorbed on pyrite by chemisorption, which was stronger than the physisorption between GM and pyrite, SBX could still be adsorbed on pyrite in the presence of GM. The interaction energy between talcum and GM was much more negative than that between pyrite and GM, which indicated the interaction between talcum and GM was stronger. Meanwhile, the interaction energy between talcum and GM was more negative than that between talcum and SBX, which revealed that talcum preferred to adsorb GM in the presence of both GM and SBX. Therefore, GM preferred to interact with talcum and could selectively depress talcum in the separation of pyrite from talcum.

Flotation separation of pyrite from arsenopyrite using sodium carbonate and sodium humate as depressants

Arsenic is hazardous to the environment, and needs special precautions in smelting operations. The separation of pyrite and arsenopyrite is therefore required; however, the process is difficult. The present work employed the combination of sodium carbonate (Na2CO3) and sodium humate (HA) as arsenopyrite depressants. In this regard, flotation tests, zeta potential measurements, adsorption tests and electrochemical measurements were performed. The microflotation tests showed that regardless of the presence or absence of copper sulfate, the recoveries vs. pH of both minerals were quite similar, thereby showing the difficulty of separation. Using copper sulfate is required in achieving flotation separation under weak alkaline. HA alone could depress the arsenopyrite flotation and show good selectivity towards pyrite. Interestingly, compared to the single depressant of sodium humate, higher pyrite and lower arsenopyrite recoveries were obtained when using the combination. The zeta potential, adsorption capacity and cyclic voltammetry showed that HA could strongly adsorb on arsenopyrite, whilst the adsorption on pyrite is weaker. More importantly, the presence of Na2CO3 enhanced the adsorption of HA on arsenopyrite, but reduces that on pyrite, which is consistent with the flotation results. A satisfactory flotation performance was obtained after a closed-circuit flotation using the combined depressants. This work puts forward an environmentally friendly strategy for the separation of pyrite and arsenopyrite.

Desulphurization of coals of different ranks in the presence of slimes by reverse flotation

In this paper, the flotation separation of pyrite from sub-bituminous and meta-bituminous coals in the presence of slimes was investigated. The sub-bituminous coal and the meta-bituminous coal have significant differences in their surface properties compared with pyrite. The flotation experiments were performed in the presence of potassium amyl xanthate (PAX) collector. The adsorption of PAX on pyrite was significant while that on the coal surfaces was negligible. The recovery of pyrite from sub-bituminous coal increased by 55% when the concentration of PAX increased from 1×10−4mol/L to 5×10−4mol/L. Similarly, pyrite recovery from the meta-bituminous coal increased by up to 60% for the coarser size fraction upon increasing PAX concentration from 1×10−4mol/L to 5×10−4mol/L. Before the de-sliming process, the flotation recovery of pyrite increased with decreasing coal particle size whereas the opposite is true for pyrite grade. Desliming reduced the adsorption amount of PAX on pyrite by more than 50% because of the removal of fine particles that would otherwise be available for adsorption. Desulphurization of fine coal appears to be challenging probably due to the increased entrainment of fine coal particles during pyrite flotation. The de-sliming process increased pyrite grade by >20% for the meta-bituminous coal and by 10% for the sub-bituminous coal. The results suggest that excessive collector consumption by fine particles and slimes, and entrainment are the main challenges in separating pyrite from coal particles.

The flotation separation of pyrite from serpentine using lemon yellow as selective depressant

To limit the adverse effect of serpentine on the flotation of pyrite, lemon yellow (LY) was used as a potential depressant for serpentine, and the depression effects and mechanisms were systematically investigated in this paper. Micro-flotation results revealed that the addition of LY could efficiently limit the detrimental effect of serpentine on pyrite flotation with a maximum increase of pyrite recovery from 14% to 96% at pH 9.0. X-ray photoelectron spectroscopy analysis indicated that LY adsorbed on serpentine surface through physical interaction, and electrostatic interaction was considered as the main driving force. Zeta potential results demonstrated that the serpentine surface charge changed from positive to negative after interacting with LY. Thus, the electrostatic attraction between pyrite and serpentine was converted to electrostatic repulsion. Adsorption measurements showed that the adsorption density of potassium butyl xanthate (PBX) on pyrite surface regained after the addition of LY in the presence of serpentine, and thus the pyrite floatability was restored.

The effect of 2-phosphonobutane-1,2,4-tricarboxylic acid on the flotation separation of pyrite from lizardite

To remove lizardite slimes from pyrite surface in pyrite-lizardite system, 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) was introduced as a possible depressant for lizardite slimes. Micro-flotation test results showed that PBTCA can remove lizardite slimes from pyrite surface and the floatability of pyrite was restored. Zeta potential measurements indicated that the surface charge of lizardite transformed from positive to strongly negative values by the addition of PBTCA because of the adsorption of PBTCA at lizardite surface. As a result, the interaction of pyrite and lizardite converted from electrosteric attraction to electrosteric repulsion, and therefore the SBX adsorption at pyrite surface was promoted and the floatability of pyrite was restored.

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.

The flotation separation of pyrite from pyrophyllite using oxidized guar gum as depressant

The flotation separation of pyrite from pyrophyllite using oxidized guar gum (OGM) as depressant has been studied through flotation tests, adsorption and FTIR spectra measurements. Flotation tests on a single mineral and mixed binary minerals show that the reagent schedule of depressant OGM 50mg/L, collector SIBX (sodium isobutyl xanthate) 0.2mmol/L and frother DIDE (diethyleneglycol dimethyl ether) 7mg/L at pH6 could achieve selective flotation separation of pyrite from pyrophyllite (a concentrate with S grade of 48.0% and recovery of 86.9% was achieved by the mixed binary minerals flotation), which indicate that OGM has selective depression effect on pyrophyllite minerals while has little depression effect on pyrite. Adsorption and FTIR spectra measurements illustrate that OGM could absorb more strongly on pyrophyllite surface than on pyrite surface, and the interaction of OGM with the pyrophyllite surface consists of a dominant chemisorptions while the OGM cannot interfere with the FTIR spectrum of pyrite. This is the reason why OGM has excellent depression selectivity for pyrophyllite and negligible effect on pyrite flotation.

The flotation separation of pyrite from arsenopyrite using hexyl thioethylamine as collector

The floatability of pyrite and arsenopyrite was studied using sodium ethyl xanthate (NaEX), potassium amyl xanthate (KAX) and hexyl thioethylamine hydrochloride (HTA). The experiments were conducted on individual minerals and on the mixtures as a function of pH and collector concentration employing Hallimond tube and bench flotation equipment. The performance of HTA, which is an amine type cationic collector, was found to be distinctively good at alkaline pH values unlike xanthates that give good recoveries at acidic pH region. The preliminary work showed that the best separation could be achieved with HTA by the selective flotation of pyrite. Separation tests using HTA were carried out with a Hallimond tube and Denver flotation cell. The selective flotation of pyrite from arsenopyrite was achieved at around pH 11, employing HTA without using any regulators to depress arsenopyrite.

Role of collector and frother, and of hydrophobicity/oleophilicity of pyrite on the separation of pyrite from coal by flotation

The effect of dodecane and three different alcoholic frothers [n-butylalcohol, n-hexylalcohol and methylisobutylcarbinol (MIBC)], on the flotation separation of pyrite from Pittsburgh No. 8 coal was investigated. Addition of dodecane resulted in a decrease of selectivity and this was attributed on the basis of the induction time measurements to the smaller difference between the oleophilicities of coal and pyrite than the difference between their hydrophobicities. The results of induction time measurements also showed pyrite to be hydrophilic at the air-water interface and hydrophobic at the oil-water interface. Frother consumption was found to be dependent on the molecular weight and chemical structure with MIBC, the larger and more complex one, being the most effective. However, the frother type was found to have no measurable effect on the separation itself of pyrite and non-pyritic minerals from coal.