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。     

O，O-二（2，3-二羟基丙基）二硫代磷酸对黄铜矿和方铅矿的选择性抑制

以丁铵黑药为捕收剂,添加一种新型抑制剂O,O-二（2,3-二羟基丙基）二硫代磷酸（DHDTP）对黄铜矿和方铅矿进行浮选,通过动电位和吸附量的测试,探讨抑制剂DHDTP与矿物的相互作用机理。浮选试验结果表明：在整个pH范围内,抑制剂DHDTP对黄铜矿的抑制作用很弱;在pH6～10范围内,抑制剂DHDTP对方铅矿有很强的抑制作用。随着抑制剂DHDTP用量的增多,方铅矿的回收率迅速降低,而黄铜矿的回收率只有小幅度的降低。在DHDTP用量278mg／L、矿浆pH6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较好,分别为24．08％和81％。通过动电位和吸附量的测试结果可知,DHDTP在方铅矿上的吸附能力明显高于黄铜矿的。     

电化学调控浮选能带模型及应用(Ⅲ)——有机抑制剂对硫化矿物能带结构的影响

用能带理论分析了电化学调控浮选模型 ,提出了采用有机抑制剂来改变矿物电子能级、实现硫化矿的浮选分离。研究了有机抑制剂对矿物抑制的两种电化学机理 :一是有机抑制剂增加了矿物费米能级 ,矿物电子向黄药的空能级传递 ,双黄药被还原 ;二是有机抑制剂降低了矿物边缘能级 ,从而导致矿物表面电子密度增大 ,黄药空能级被电子占据 ,双黄药被还原。开发了 5种电化学浮选分离新型有机抑制剂 ,实现了 8种人工混合精矿和3种矿石的浮选分离。     

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.     

Flotation of Xinhua molybdenite using sodium sulfide as modifier

The feasibility of using sodium sulfide as the sole modifier for the flotation of Xinhua molybdenite ore was examined. The potential mechanisms involved in the different flotation systems were discussed. The comparative flotation results reveal that in the kerosene-sodium silicate flotation system, better recovery and grade of the molybdenum are obtained using sodium sulfide as the slurry pH adjustment agent than using CaO. Under the optimal conditions (64 g/t kerosene and 6 kg/t Na2S), satisfied recovery and grade of molybdenite concentrate can be achieved (84% and 8.2%, respectively), indicating that sodium sulfide is a potential substitute modifier of sodium silicate. The open-circuit flotation test results further confirm the effectiveness of sodium sulfide which may render recycling the tailing water possible and make the flotation process more environmental acceptable and more economical due to the less use of kerosene and scavengers.     

Synergistic depression mechanism of zinc sulfate and sodium dimethyl dithiocarbamate on sphalerite in Pb−Zn flotation system

The depression mechanism of zinc sulfate (ZnSO₄) and sodium dimethyl dithiocarbamate (DMDC) as the combined depressant on sphalerite was investigated by micro-flotation experiments, ion complexing tests, contact angle tests and X-ray photoelectron spectroscopy (XPS) analysis. The micro-flotation tests revealed that ZnSO₄+DMDC had a better selective depression effect on sphalerite than using single ZnSO₄ or DMDC. Ion complexing tests confirmed that DMDC had a strong complexing capacity with lead ions or hydroxy complexes. Contact angle tests illustrated that ZnSO₄+DMDC makes the sphalerite surface more hydrophilic than ZnSO₄ or DMDC. XPS analysis indicated that the combined depressant could prevent collector adsorbing on the Pb-activated sphalerite surface by a competitive adsorption method, while the combined depressant and collector were co-adsorbed on galena surface.     

钛渣中钙钛矿的浮选分离及其机理

研究了捕收剂油酸、羟肟酸、十二烷胺双甲基膦酸 ,抑制剂氟硅酸钠、水玻璃对改性渣中钙钛矿浮选的影响。通过浮选溶液化学计算、矿物动电电位、红外光谱等研究 ,探讨了羟肟酸在钙钛矿表面的作用和水玻璃抑制钛辉石的作用机理。结果表明 :以羟肟酸为捕收剂 ,水玻璃为抑制剂可实现钙钛矿与钛辉石等的浮选分离。钙钛矿和钛辉石晶体表面的Ca,Ti质点密度不同 ,所处的位置及活性不同 ,造成二者浮游性有一定的差异 ;钙钛矿在整个研究范围内 ζ电位始终为负值 ,但在阴离子捕收剂C5-9羟肟酸中可浮性良好 ,表明C5-9羟肟酸在钙钛矿表面发生了化学吸附。红外光谱研究证实 ,C5-9羟肟酸的CN ,N—O官能团与钙钛矿表面的钛质点发生了化学键合。     

Effect of sodium silicate pretreatment on phosphate layer: Morphology and corrosion resistance behavior

Phosphating is a widely adopted treatment in industry for many purposes. In this paper, carbon steel was pretreated with sodium silicate before phosphating. X‐ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements were used to evaluate the pretreatment effect by sodium silicate on the phosphating layer. The results demonstrate that the phosphate layer pretreated by sodium silicate has a better corrosion resistance as compared with the un‐pretreated ones. More compact and uniform coatings composed of finer crystals were obtained with the pretreatment of sodium silicate.     

Interaction mechanism of ferrate(VI) with arsenopyrite surface and its effect on flotation separation of chalcopyrite from arsenopyrite

Potassium ferrate (K₂FeO₄) was used as a novel environmental-friendly depressant, and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate (PEX) as a collector was investigated by flotation experiments, contact angle measurements, adsorption measurements, localized electrochemical impedance spectroscopy (LEIS) measurements, and X-ray photoelectron spectroscopy (XPS) analyses. The results showed that K₂FeO₄ strongly depressed arsenopyrite in a pH range of 4—11, and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^—4 mol/L K₂FeO₄ and 5×10^—5 mol/L PEX at pH 8 or 10. In the presence of K₂FeO₄ and PEX, the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly. LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface. XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.     

Effects of sodium carbonate and calcium chloride on calcite depression in cationic flotation of pyrolusite

In the cationic flotation of pyrolusite using dodecyl ammine (DDA), the depressive effect of sodium carbonate and calcium chloride on the calcite mineral was investigated systematically through flotation experiments, FTIR analysis, contact angle measurements and zeta potential tests. The microflotation experiments showed that both depressant agents decrease the flotation recovery of calcite significantly. In addition, sodium carbonate acts as activator agent for pyrolusite, and increases its floatability. The flotation experiments and contact angle measurements indicated that the selective depression effect of sodium carbonate on the calcite mineral is more than that of calcium chloride. As evidenced by zeta potential and FT-IR analysis, sodium carbonate decreases the negative charges on the surface of calcite mineral and subsequently reduces the adsorption of DDA collector through electrostatic forces. At a pH of 7.5, using 2000 g/t DDA and 1500 g/t sodium carbonate, a pyrolusite concentrate containing almost 40% MnO with 71.5% recovery is achieved by carrying out the ore flotation experiments on the tabling pre-concentrate.     

Mechanism of sodium sulfide on flotation of cyanide-depressed pyrite

The mechanism of sodium sulfide (Na₂S) on the flotation of cyanide-depressed pyrite using potassium amyl xanthate (PAX) as collector was investigated by flotation test and electrochemical measurements. The flotation results show that both PAX and Na₂S can promote the flotation recovery of cyanide-depressed pyrite and their combination can further improve the pyrite flotation recovery. Electrochemical measurements show that PAX and Na₂S interacted with cyanide-depressed pyrite through different mechanisms. PAX competed with cyanide and was adsorbed on the pyrite surface in the form of dixanthogen, thus enhancing the hydrophobicity and flotation of cyanide-depressed pyrite. Unlike PAX, Na₂S rendered the pyrite surface hydrophobic through the reduction of ferricyanide species and the formation of elemental sulfur S⁰ and polysulfide. The combined application of PAX and Na₂S induced superior pyrite flotation recovery because of a synergistic effect between PAX and Na₂S.     

假乙内酰硫脲酸在铜-钼浮选分离中的抑制性能(英文)

将合成的假乙内酰硫脲酸(PGA)用作铜-钼分离抑制剂。该药剂闭路实验结果表明:假乙内酰硫脲酸在较小的用量下对黄铜矿有较强的抑制作用,经一次粗选、一次扫选、两次精选,可获得Mo品位大于26%、回收率大于89%的浮选指标,而用Na2S做抑制剂时钼的回收率下降了2%。药剂吸附量测试结果表明,PGA与丁基黄药在矿物表面发生竞争吸附,PGA在黄铜矿表面上的吸附量远大于在辉钼矿表面的。红外光谱分析表明,PGA在黄铜矿表面是化学吸附,而在辉钼矿表面属于物理吸附。前线轨道计算结果表明,在PAG分子中,硫原子是反应活性的中心。利用矿物、丁黄药及PGA的费米能级能量大小可以从电化学作用角来度解释PGA的抑制机理。     

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.     

Depressing behaviors and mechanism of disodium bis (carboxymethyl) trithiocarbonate on separation of chalcopyrite and molybdenite

This work focuses on the organic depressant, disodium bis(carboxymethyl) trithiocarbonate (DBT), as a selective depressant in copper-molybdenum sulfide flotation separation. Micro-flotation, Zeta potential, FTIR and XPS measurements were carried out to investigate the selective depression mechanism of DBT on chalcopyrite. Zeta potential and FTIR measurements revealed that DBT had higher affinity for chalcopyrite than molybdenite and the XPS results of chalcopyrite before and after treatment with DBT further proved that DBT adsorbed on chalcopyrite surface. The investigation indicates that the mechanism of DBT adsorbing on chalcopyrite is mainly physical adsorption. Locked circuit experiments were carried out and the results showed that DBT could be considered as a cleaner option in commercial Cu-Mo flotation separation circuits.     

Structure–activity relationship and mechanisms of reagents used in scheelite flotation

Effects of carboxylic acid collector,benzohydroxamic acid(BHA),sodium hexametaphosphate(SHAP),sodium silicate,and oxalic acid on scheelite flotation were studied through flotation tests,quantum chemical calculation,and flotation solution computational chemistry.In terms of the calculation results,the relationship between chemical reactions occurring on the scheelite surface and molecular structures of the reagents were analyzed.The results show that BHA and carboxylic acid collectors interact with scheelite in different forms and the recovery of scheelite using sodium oleate as collector declines successively from SHAP,sodium silicate,to oxalic acid.Moreover,it is found that the performance of depressant in scheelite flotation is directly related to the group electronegativity,indicating that the latter is a dominant factor that determines the former.These findings will be helpful to the academic research communities of scheelite flotation.     

石灰和氢氧化钠对黄铁矿浮选抑制的电化学行为

采用热力学计算及交流阻抗和循环伏安等电化学方法研究石灰和氢氧化钠对黄铁矿浮选抑制行为的影响。单矿物浮选试验结果表明:当pH值为7.0~11.5时,石灰对黄铁矿的抑制作用强于氢氧化钠;当pH>11.5时,石灰和氢氧化钠均对黄铁矿表现出强烈的抑制作用。热力学计算和电化学测试结果表明:黄铁矿表面法拉第反应电阻Rp随pH值的升高而减小,利于黄铁矿表面的电子传递,从而使得黄铁矿表面更易于氧化,导致Fe(OH)3和SO42-等亲水性物质的生成;在碱性条件下,黄铁矿表面电阻Rs增大,说明其表面覆盖不良导电物质;在石灰体系中,同时存在钙膜的影响,使得Rs增加的幅度比在氢氧化钠体系中的大,该结果与浮选试验结果一致。     

Synergistic corrosion protection for galvanized steel by phosphating and sodium silicate post-sealing

To improve the corrosion resistance of phosphate coatings, the phosphated hot-dip galvanized (HDG) sheets were post-sealed with sodium silicate (water glass) solutions. The morphology and chemical composition of the composite coatings was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The effect of sodium silicate post-sealing treatment on the corrosion behaviors of phosphate coatings was investigated by neutral spray salt (NSS) tests and electrochemical measurements. The results show that after the silicate post-treatment the pores among zinc phosphate crystals are sealed with the films containing Si, P, O and Zn, leading to the formation of the continuous composite coatings on the surface of HDG steel. The corrosion resistance of the composite coatings depending on concentration of sodium silicate and post-sealing time is greatly improved by the silicate post-treatment. The optimum concentration of silicate and post-sealing time are 5 g/L and 10 min, respectively. Both the anodic and cathodic processes of zinc corrosion on the samples are suppressed conspicuously, and the synergistic protection effect of the single phosphate coatings and the single silicate films is evident. Moreover, the low frequency inductive loop in electrochemical impedance spectroscopy (EIS) is disappeared and the electrochemical impedance values are increased for more than one order of magnitude. The corrosion protection of the composite coatings is comparable to that provided by the chromic acid post-treatment.     

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%.     

Galena-pyrolusite co-extraction in sodium chloride solution and its electrochemical analysis

The co-extraction behavior of galena-pyrolusite in a sodium chloride solution and the electrochemical mechanism of this process were investigated, and some factors affecting the leaching rate of Pb and Mn were optimized. The results show that all the factors such as the concentration of NaCl, HCl and pyrolusite ore, reaction time, temperature, adding times of HCl, affect the leaching rate of Pb. The main affecting factors are the concentration of NaCl, reaction time and temperature. The Tafel polarization curves and EIS plots of the galena and pyrolusite in the NaCl solution demonstrate that during the oxidation process of galena mineral electrode, film forms on the galena surface, which prevents galena from deeper oxidation. However, the film resistance can be greatly reduced in the presence of sodium chloride, thus promoting the reaction rate of galena.     

组合抑制剂石灰和腐植酸钠在锌砷混合精矿浮选分离中对毒砂的选择性抑制机理

采用石灰和腐植酸钠作为经硫酸铜活化和丁黄药捕收后毒砂的组合抑制剂.纯矿物浮选试验表明,组合抑制剂石灰和腐植酸钠能选择性地抑制毒砂.实验室小型闭路试验结果表明,石灰和腐植酸钠的协同抑制作用能较好地实现闪锌矿和毒砂的浮选分离,得到锌精矿中锌品位为51.21％、锌回收率为92.21％的良好指标.通过接触角测试、吸附量测试和X...