Improvement of flotation behavior of Mengzi lead-silver-zinc ore by pulp potential control flotation

The electrochemical behavior of Mengzi lead-silver-zinc ore flotation system was studied. Based on the electrochemical characteristics of sulfide mineral flotation system, a stage potential control flotation was developed with the main parameters of pulp potential（φp）, pH value and collector dosage. Using N,N＇ diphenylamino-dithiolphosphoric acid（NNDDC） as a collector, which has good selectivity for galena flotation at pH 8.8 and pulp potential 330 mV, DDTC is used as secondary collector to improve both the grade and recovery of Pb and Ag. The pulp potential values significantly influence the floatability of practical minerals and single minerals when using NNDDC as the collector. The flotation recovery of galena reaches 85% at about 0.3 V and pH8.8. With the usage of pulp potential control during grinding and flotation, the new pulp electrochemical technology for Mengzi lead-silver-zinc ore flotation was developed. The results show that the grades of Pb and Ag of galena concentrate are 55% and 1 800 g/t, respectively, while the recoveries of Pb and Ag are 86.5% and 65%, respectively, the grade of Zn of marmatite concentrate is 42.5%, and the recovery of Zn is 91.25%.     

Electrochemical characteristics of couple electrode of galena-pyrite in different solutions

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｅｌｅｃｔｒｏｃｈｅｍｉｓｔｒｙｐｌａｙｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｏｎｔｈｅｆｌｏｔａｔｉｏｎｏｆｓｕｌｆｉｄｅｍｉｎｅｒａｌｓ .Ｅｘｔｅｎｓｉｖｅｒｅｓｅａｒｃｈｈａｓｄｅｍｏｎｓｔｒａｔｅｄｔｈａｔｔｈｅｆｌｏｔａｔｉｏｎｏｆｓｕｌｆｉｄｅｍｉｎｅｒａｌｄｅｐｅｎｄｓｓｔｒｏｎｇｌｙｏｎｔｈｅｏｘｉｄａｔｉｏｎｐｏｔｅｎｔｉａｌｉｎｔｈｅｅｎ ｖｉｒｏｎｍｅｎｔｓｕｒｒｏｕｎｄｉｎｇｓ[1～ 4 ] .Ｃｏｎｔｒｏｌｌｉｎｇｔｈｅｅｌｅｃｔｒｏ ｃｈｅｍｉｃａｌ…     

FTIR spectroscopic study of electrochemical flotation of jamesonite-diethyldithiocarbamate system

1 Introduction Flotation electrochemistry and modern surface analytical techniques have enhanced our understanding of reagent-mineral interaction mechanism. Great progress has been made by applying various electrochemical techniques to investigate the int…     

硫化矿浮选体系中辉银矿的浮选行为研究

单矿物浮选实验结果表明,辉银矿在p H为9~10的弱碱性介质下可浮性较好,而在p H大于11的强碱介质下可浮性明显降低。通过热力学计算了乙基黄药、丁铵黑药和乙硫氮浮选辉银矿的临界p H分别为9.38、9.11和11.59。上述3种捕收剂在辉银矿表面的吸附量测定结果表明,弱碱性介质中各捕收剂在辉银矿表面的吸附量已经达到最大值,进一步增加p H,吸附量会大幅降低,这可能是由于辉银矿表面在强碱性介质中先生成了氢氧化银沉淀,后进一步水解生成了亲水性的氧化银薄膜,阻碍了捕收剂与辉银矿的吸附过程,从而导致辉银矿可浮性降低。此外,弱碱性介质中3种捕收剂在辉银矿表面的饱和吸附量排序为丁铵黑药乙基黄药乙硫氮,表明丁铵黑药更易吸附在辉银矿表面,对银矿物具有更好的捕收性能。     

Effect of mineral processing wastewater on flotation of sulfide minerals

The effects of mineral processing wastewater on sulfide minerals were investigated by flotation, infrared spectrometry and electrochemistry test. The results show that lead-concentrate water can improve the flotation of galena, while the sulfur-concentrate water has negative effect on flotation of galena compared with distilled water. The flotation behavior of pyrite is contrary to that of galena in three kinds of water. Infrared spectra indicate that the residual collector in the lead-concentrate water is beneficial to the formation of lead xanthate on the surface of galena. Electrochemistry results indicate that electrochemistry reaction on galena surface has apparent change. The anode polarization is improved and cathode polarization is depressed.     

Floc flotation of marmatite fines in aqueous suspensions induced by butyl xanthate and ammonium dibutyl dithiophosphate

The hydrophobic flocculation of marmatite fines in aqueous suspensions induced by butyl xanthate (KBX) and ammonium dibutyl dithiophosphate (ADD) was investigated using laser particle size analysis, microscopy analysis, electrophoretic light scattering, contact angle measurement and infrared spectroscopy. The studies were performed on single minerals with size ≤20 µm by varying several parameters, including pH, collector concentration and kerosene addition. The results show that the floc flotation closely correlated with the size of flocs and the particle hydrophobicity, but was not lowered with increasing the particle surface charges due to collector adsorption. Under good operating conditions, the floc flotation of marmatite fines as a function of KBX and ADD can all reach floatability over 90%, in comparison with conventional flotation obtaining floatability of about 60%. It also has been found that a small addition of kerosene greatly improved the floc flotation because of the formation of oil films on marmatite particles. The results of FTIR spectra indicate that adsorption of the two collectors onto marmatite were chemical adsorption.     

Electrochemical mechanism and flotation of chalcopyrite and galena in the presence of sodium silicate and sodium sulfite

The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate, respectively, as a single depressant and their mixture as a combined depressant. Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant (>80%) within the studied dosage range. Galena flotation was severely depressed with descending depressing order as follows: combined depressant > sodium silicate > sodium sulfite. Electrochemical analysis confirmed the high affinity of depressants on the galena surface, resulting in the formation of hydrophilic species, such as lead sulfite, lead sulfate, and lead orthosilicate. The oxidation of chalcopyrite sutrface and depressants did not exhibit any signals; conversely, the self-oxidation of chalcopyrite was depressed. The results of cyclic voltammograms well agreed with flotation results, demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.     

Selective depression of copper-activated sphalerite by polyaspartic acid during chalcopyrite flotation

Environmentally friendly flotation reagent, polyaspartic acid (PAPA), was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite. The depression mechanism of PAPA was revealed by contact angle measurements, Zeta potential measurements, Fourier transform infrared spectroscopy (FT-IR) analysis and inductively coupled plasma (ICP) measurement. The micro-flotation tests with single minerals showed that PAPA selectively depressed Cu-activated sphalerite, while chalcopyrite remained floatable. Moreover, a concentrate containing 31.40% Cu with a recovery of 92.43% was obtained in flotation tests of artificially mixed minerals. Results of contact angle measurements, Zeta potential measurements and FT-IR spectrum revealed that PAPA exerted a much stronger adsorption on Cu-activated sphalerite surface than on chalcopyrite surface, preventing the further adsorption of sodium diethyl dithiocarbamate (DDTC) on its surface. ICP measurements indicated that PAPA had an excellent complexing ability with Cu²⁺ in flotation pulp, weakening the activation of Cu species on sphalerite surface and producing selective depression.     

含银方铅矿表面性质及捕收机理模拟计算研究

采用丁铵黑药、乙基黄药和乙硫氮3种硫化矿捕收剂对含银方铅矿进行浮选试验,基于密度泛函理论对浮选机理进行了模拟计算研究。浮选试验表明,与高碱性矿浆相比,含银方铅矿更适宜在pH为9.5的弱碱性矿浆中浮选;丁铵黑药表现出对含银方铅矿更强的选择性和捕收性。捕收机理研究结果表明,与理想方铅矿相比,含银方铅矿的带隙更窄,此外费米能级附近也新增了银原子的4d轨道,表明含银方铅矿具有更强的电化学反应活性。根据前线轨道理论,当采用丁铵黑药和乙基黄药做捕收剂时,含银方铅矿的前线轨道有效质量更低,表明含银方铅矿更易与这2种捕收剂发生吸附;随着银含量的增加,吸附过程的前线轨道有效质量呈明显下降趋势,也表明银原子会增强捕收剂与矿物表面的吸附过程。分子动力学模拟计算结果表明,丁铵黑药在含银方铅矿表面的吸附能最低,表明丁铵黑药对含银方铅矿选择性最好。     

Synthesis of novel thionocarbamate for copper−sulfur flotation separation and its adsorption mechanism

As a novel collector, O-isopropyl-N,N-diethyl thionocarbamate (IPDTC) was designed and synthesized for copper?sulfur flotation separation. Density functional theory calculations were performed to investigate the electronic structures of IPDTC. The results showed that IPDTC had higher energy of the highest occupied molecular orbital but lower electronegativity than O-isopropyl-N-ethyl thionocarbamate (Z?200). It was predicted that IPDTC had strong collection ability according to the reaction energy criteria. Flotation results demonstrated that the collecting ability of IPDTC to chalcopyrite and pyrite was stronger than that of Z?200. Then, the flotation mechanism was analyzed by measurements of surface tension, adsorption capacity, XPS, FTIR and zeta potential. These results indicated that IPDTC could reduce the solution surface tension. The adsorption capacity of IPDTC on chalcopyrite was higher than that on pyrite, consistent with the results of the flotation tests. FTIR, zeta potential and XPS results also demonstrated that IPDTC was strongly absorbed on the chalcopyrite surface by formation of Cu—S—C bonds, but showed a weak affinity on the pyrite surface.     

Inhibition of copper corrosion in sodium chloride solution by the self-assembled monolayer of sodium diethyldithiocarbamate

Sodium diethyldithiocarbamate (DDTC) self-assembled monolayer (SAM) on copper surface has been investigated by SERS and EDS and the results show that DDTC SAM is chemisorbed on copper surface by its S atoms with tilted orientation. Corrosion inhibition ability of DDTC SAM was measured in 3% NaCl solution using electrochemical methods. The impedance results indicate that the maximum inhibition efficiency of DDTC SAM can reach 99%. Quantum chemical calculations show that DDTC has relatively small ΔE between HOMO and LUMO and large negative charge in its two sulfur atoms, which facilitates the formation of a DDTC SAM on copper surface.     

Adsorption mechanism of styryl phosphonate ester as collector in ilmenite flotation

A styryl phosphonate ester (SPE) collector was used to improve the flotation performance of ilmenite, and the adsorption mechanism and model were revealed and established, respectively. Microflotation tests showed that SPE exhibited a stronger collecting ability for ilmenite than the traditional collector styrene phosphonic acid (SPA). Zeta potential measurements revealed that both SPE and SPA could negatively shift the zeta potential of ilmenite, while SPE had more effects than SPA, suggesting the stronger adsorption of SPE. The analysis of X-ray photoelectron spectroscopy confirmed the chemisorption of SPA and SPE onto the Fe/Ti sites of ilmenite. According to frontier orbital theory, the chemical activities of SPE are greater than those of SPA. The partial densities of states analysis indicated that the PO—H groups of the collectors could interact with the Ti/Fe atoms of the ilmenite surface to generate a stable four-membered ring. The bonding model of the collector and (104) ilmenite surface showed that the adsorption energy of SPE was higher than that of SPA. Overall, SPE presented a better collecting ability and interaction effect for ilmenite flotation than SPA, and had the potential to replace SPA in the industry.     

Flotation separation of molybdenite and talc using tragacanth gum as depressant and potassium butyl xanthate as collector

Tragacanth gum (TG) was explored as a depressant to realize the flotation separation of molybdenite and talc. The flotation experiments indicated that when using potassium butyl xanthate (PBX) as a collector, molybdenite showed excellent floatability while talc was completely depressed by TG, thus realizing the flotation separation of the two minerals. X-ray photoelectron spectroscopy (XPS) analysis results showed that TG was adsorbed on molybdenite surface via chemisorption. The results of contact angle measurement, Fourier transform infrared (FTIR) spectroscopy, and time-of-flight secondary ion mass spectrometry (ToF-SIMS) indicated that the pre-adsorption of TG on molybdenite could not hinder the further chemisorption of PBX on molybdenite. Because PBX has no collecting ability on talc, the flotation separation of molybdenite and talc came true using PBX to collect molybdenite and TG to depress talc.     

锌阳极泥矿浆中铅银矿物的赋存状态及其与黄药的作用(英文)

用热力学方法分析锌阳极泥矿浆的强氧化背景矿浆电位及其对铅、银和黄原酸盐赋存状态的影响。结果表明,在强氧化背景矿浆电位下,铅以 Pb2+或 PbSO4形式存在,银以金属银、AgCl 和 Ag2O 等形式存在,黄原酸盐以其氧化后的二聚物双黄药形式存在。XRD 分析结果表明,锌阳极泥中的铅矿物主要是铅矾,主要的银矿物之一是氯银矿。单矿物浮选实验表明,双黄药对氯银矿的捕收力远强于对铅矾的。用 Material Studio(Adsorption Locater)模块计算了两种吸附质(铅矾和氯银矿)与不同吸附剂(双黄药, H2O, OH-, Cl-, SO42-)的作用能变化。结果表明,在存在 SO42-的条件下,双黄药只能吸附在氯银矿表面。红外光谱测试证实了双黄药对氯银矿的选择性吸附作用。     

ELECTROCHEMICAL KINETICS ON BULK CONCENTRATE SEPARATION OF PYRITE AND GALENA

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｅｐａｒａｔｉｏｎｏｆｐｕｌｐｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｆｌｏａｔａｔｉｏｎｏｆｓｕｌｆｉｄｅｍｉｎｅｒａｌｓｄｅｐｅｎｄｓｏｎｄｉｆｅｒｅｎｃｅｓｉｎｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｔｈｅｔｈｒｅｆａｃｔｏ...     

云南某含银低品位铅锌矿工艺矿物学特性研究

通过化学分析、光学显微镜观察、自动矿物分析仪(MLA)分析等手段,对云南某含银低品位铅锌矿进行了工艺矿物学研究。研究结果表明,矿石中可供选矿回收的有价元素为铅、锌及银;铅、锌主要以方铅矿、闪锌矿的形式存在;银少量以淡红银矿、浓红银矿、黝锑银矿等游离银矿物形式存在,但大量以微细包裹体或类质同象形式存在于铅矿物中;脉石矿物主要为石英,其次为绢云母、方解石、高岭土等。方铅矿及闪锌矿共生关系密切,交代结构突出、包裹关系复杂,导致矿物充分单体解离较困难;绢云母、高岭土等脉石矿物易泥化,会对浮选分离造成不利影响。     

Flotation and electrochemical behaviors of chalcopyrite and pyrite in the presence of N-propyl-N′-ethoxycarbonyl thiourea

The characteristics of N-propyl-N′-ethoxycarbonyl thiourea (PECTU) were studied in the flotation experiments of chalcopyrite and pyrite compared with butyl xanthate (BX). The interaction mechanism between mineral and PECTU was investigated according to zeta potential and electrochemistry measurements in the presence of PECTU. The results proved that PECTU performed a stronger ability to capture chalcopyrite and a better selectivity against pyrite. The zeta potential of chalcopyrite was positively shifted after interacting with PECTU, which indicated that the collector PECTU was obviously adsorbed on chalcopyrite surface. The cyclic voltammetry and Tafel curves results indicated that the oxidation and corrosion rates of chalcopyrite surface were limited in the presence of PECTU, while the effect of PECTU on pyrite in weak alkaline solution can be neglected basically according to the results of zeta potential and electrochemical tests.     

2,3-二羟基丙基二硫代碳酸钠对铜铅硫化矿可浮性的影响

在丁铵黑药浮选体系中,研究含有—OH和—CSS—的2,3-二羟基丙基二硫代碳酸钠（SGX）对黄铜矿和方铅矿的抑制效果,并通过动电位和吸附量的测试,探讨抑制剂SGX与矿物的相互作用机理。浮选试验研究结果表明：在整个p H范围内,抑制剂SGX对黄铜矿有活化作用,而对方铅矿有很强的抑制作用。随着抑制剂SGX用量的增加,方铅矿的回收率迅速下降,而黄铜矿的回收率有小幅度的升高。在矿浆p H为6的条件下,人工混合矿浮选得出的精矿中铜的品位和回收率分别为29.52%和82.15%。通过动电位和吸附量的测试结果可知,抑制剂SGX在方铅矿表面有较强的吸附,而在黄铜矿表面吸附很弱。     

N-十二烷基乙二胺的捕收性能及其在矿物表面的吸附特性(英文)

通过单矿物实验考察N-十二烷基乙二胺(ND)对石英和赤铁矿的捕收能力。结果表明,ND对石英具有很强的捕收能力,而对赤铁矿的捕收能力较弱。在抑制剂存在的情况下,石英和赤铁矿体现出不同的浮游特性。与十二胺相比,ND对石英具有更强的捕收能力。人工混合矿分选实验结果表明,在矿浆pH值为7.27、捕收剂用量为41.7mg/L、抑制剂用量为3.33mg/L 时取得较好的分选效果,此时精矿中的铁品位为59.92%、铁回收率为88.85%。极性基团性能计算结果表明,与十二胺相比,ND具有更强的捕收能力和更好的选择性。Zeta电位测试和红外光谱分析结果表明,ND与石英表面发生静电和氢键吸附。     

Adsorption of octanohydroxamic acid at fluorite surface in presence of calcite species

The surface properties of fluorite are often affected by dissolved gangue species (e.g., calcite) during the flotation process. Microflotation testing with and without the addition of calcite supernatant was conducted using octanohydroxamic acid (OHA) as the collector. The results revealed that dissolved calcite species significantly affected the flotation behavior of fluorite. Fourier transform infrared spectra confirmed that the decrease in flotation recovery was linked to lower OHA adsorption. Solution chemistry analysis indicated that CaCO₃ and Ca²⁺ from the calcite supernatant were the most favorably adsorbed species, and X-ray photoelectron spectroscopy analysis confirmed the surface adsorption of calcite species. Density functional theory simulations provided a detailed analysis of the multidentate adsorption configuration of OHA, which was the most favorable for adsorption on the fluorite surface. The adsorption energy calculation showed that the calcite dissolved species were more stably adsorbed on the fluorite surface than OHA. The pre-adsorption of calcite dissolved species hindered the adsorption of OHA due to electrostatic repulsion.