某选矿厂工业回水中离子对黄铁矿浮选的影响机制

通过黄铁矿纯矿物浮选实验、紫外分光光度计(UV-Vis)分析、Zeta电位测定和傅里叶变换红外光谱(FT-IR)分析研究了工业回水中超标离子(NH+4,Mg~(2+),Ca~(2+),F-)对黄铁矿浮选的作用机制。结果表明,回水中NH_4~+可以提高矿物表面的电位,扩大黄铁矿浮选的pH值范围,红外光谱表明其能促进黄铁矿与黄药发生化学吸附,且矿物表面黄药吸附量随着NH+4的增加而增加,经NH_4~+活化后,黄铁矿浮选回收率提高15.5%。而回水中Ca~(2+),Mg~(2+),F-会抑制黄铁矿对黄药的吸附,浮选回收率平均下降10%。其中,Ca~(2+),Mg~(2+)在黄铁矿表面易形成亲水膜,阻碍黄铁矿对黄药的表面吸附;Zeta电位测试发现F-吸附在矿物表面导致矿物表面带负电,与同为阴离子的黄原酸根离子形成竞争吸附,减少了黄原酸盐在黄铁矿表面的吸附量,降低了其可浮性。     

稀土矿浮选中柠檬酸对铈离子活化方解石的影响研究

通过单矿物浮选试验、Zeta电位测试和红外光谱分析等方法,研究稀土矿浮选中柠檬酸CA对Ce~(3+)离子活化方解石的去活作用机理。试验研究结果表明,矿浆中Ce3+离子的浓度低于1×10~(-4)mol/L时对方解石浮选有活化作用,采用柠檬酸CA可达到去活目的。机理分析结果表明,柠檬酸CA能与方解石表面的Ce3+离子生成一种稳定的络合物,可降低方解石表面的Zeta电位,去除Ce~(3+)离子对方解石的活化作用。     

Fe~(3+)对锂辉石浮选的影响及机理研究

通过锂辉石纯矿物的浮选试验、电动电位测试、红外光谱测试以及Fe3+溶液化学分析,系统地研究了Fe3+对锂辉石浮选的影响及其作用机制。结果表明,Fe3+的加入明显提高了锂辉石的浮选回收率;锂辉石经Fe3+活化后与捕收剂作用,其表面电位发生显著偏移,表明Fe3+在锂辉石表面发生了较强的吸附;经Fe3+活化并与捕收剂作用的锂辉石,其红外光谱中的油酸特征吸收峰明显增强,说明Fe3+的加入有利于油酸在锂辉石表面的吸附。     

Cu~(2+),Fe~(3+)对萤石浮选的活化作用机制

针对萤石选别流程复杂,浮选分离成本高以及浮选药剂对萤石的影响效果问题,本文通过单矿物浮选实验,采用溶液化学计算、Zeta电位测试和红外光谱分析的方法,研究了Cu~(2+),Fe~(3+)对萤石浮选过程的影响,并分析了Cu~(2+),Fe~(3+)对萤石浮选过程的活化机制,试验分析结果表明:油酸钠作为萤石捕收剂时,在p H=8~10范围内萤石的浮选回收率为83%;而采用Cu~(2+),Fe~(3+)作为活化剂对萤石进行活化后,萤石回收率分别达到96%和91%,提高了8%和13%,使萤石浮选效果显著提升,有明显的活化作用。溶液化学计算和XRD结果表明在p H=8~10范围内的萤石浮选溶液中,Cu~(2+)和Fe~(3+)主要以Fe(OH)3和Cu(OH)2沉淀的形式存在,进一步验证Fe~(3+),Cu~(2+)阳离子作用的有效组分是氢氧化物或者络合物沉淀;Zeta电位结果表明Fe~(3+)和Cu~(2+)两种金属离子都能使萤石的Zeta电位发生正移,而且Fe~(3+)使萤石的Zeta电位偏移幅度大于Cu~(2+)的偏移幅度,说明萤石表面的Fe~(3+)吸附量多于Cu~(2+);红外光谱分析结果表明油酸钠在分别经过Cu~(2+),Fe~(3+)活化后的萤石表面的作用方式主要为化学吸附。     

Cu（II）、Ni（II）离子在蛇纹石表面的吸附及对其浮选的影响

通过吸附量测试、纯矿物浮选和红外光谱分析,研究Cu2+和Ni2+离子在蛇纹石表面的吸附过程及对蛇纹石浮选的活化机理.Cu2+和Ni2+离子在蛇纹石表面的吸附符合二级动力学模型,等温吸附过程符合Langmuir等温吸附模型,吸附能够自发进行,为物理吸附和化学吸附的共同作用,Cu2+和Ni2+离子在蛇纹石表面的吸附量随p H值升高而增大.Cu2+和Ni2+离子在弱碱性条件下对蛇纹石具有活化作用,活化机理为铜镍的氢氧化物沉淀和羟基络合物作用于蛇纹石表面,形成活性位点,黄药在活性位点上吸附生成黄原酸铜或黄原酸镍,从而使蛇纹石表面疏水性增大,浮选受到活化.      

微细粒浸染型金矿碱性介质浮选法中药剂作用机理研究

通过浮选溶液化学和电化学研究以及借助于动电位,吸附量、红外光谱测试手段,研究了碱性介质浮选法浮选富集微细粒浸染型金矿中的黄铁矿、毒砂等载金矿物过程中碳酸钠以及硫酸铜、丁黄药在矿物表面的作用机理。     

氟碳铈矿浮选中EDTA对萤石的选择性抑制作用机制

通过单矿物及人工混合矿浮选、Zeta电位和X射线光电子能谱(XPS)测试以及溶液化学计算,研究了乙二胺四乙酸(EDTA)对氟碳铈矿和萤石浮选分离的影响及对萤石的选择性抑制作用机制,结果表明:辛基羟肟酸(OHA)作捕收剂时,EDTA对萤石浮选具有较强的抑制作用,而对氟碳铈矿的浮选几乎没有影响,氟碳铈矿和萤石浮选分离指数随EDTA用量的增加而增大,当用量由0增至2×10~(-3)mol·L~(-1)时,分离指数由1. 18提高至12. 66;XPS测试表明,EDTA降低了萤石表面以化学吸附形式存在的羟肟酸含量,而对氟碳铈矿表面吸附的羟肟酸影响较小;Zeta电位测试表明,EDTA能大幅度降低羟肟酸作用后萤石表面的Zeta电位,而对羟肟酸作用后氟碳铈矿的Zeta电位降低幅度较小,溶液化学计算表明EDTA可将萤石表面的羟肟酸钙沉淀转化为可溶性的Ca-EDTA络合物,从而减少OHA在萤石表面的吸附,但EDTA不能络合溶解氟碳铈矿表面的羟肟酸铈沉淀,对氟碳铈矿浮选影响较小,从而起到选择性抑制萤石的效果。     

国外选矿剂(三)

锡、钨及其它非硫化矿物浮选捕收剂英商 PLAISTERE and NANGER INTERNATIONAL Ltd目前开始用PH—PEP的名称,发售锡石捕收剂苯乙烯膦酸。PH—PEP浮选时,黑钨矿与锡石的浮选行为十分相似,两种矿物最佳浮选pH值,都在5～6之间,只是浮选黑钨矿时,PH—     

膦酸类锡石新型捕收剂筛选试验

研制膦酸类锡石新型捕收剂浮选细粒锡石,以解决毒性大等问题。试验结果表明:二辛基膦酸(DOPA)对浮选锡石和方解石的捕收能力较好。2—乙基己基磷酸(E~2HPA)与二(2—乙基己基)磷酸(DE~2HPA)浮选锡石单矿物后者比前者好。磷酸二辛脂(DE~2HPA)的选择性差。磷酸单辛脂(E~2HPA)对方解石和赤铁矿的捕收能力都较弱。2—丁基辛基磷酸(B~2OPA)对方解石与锡石捕收能力在碱性矿浆中,差别随pH值增大而有所扩大。α—羟基己基磷酸(H~αHPA)对方解石和锡石的捕收能力接近。其临界剂量都较大。     

钨、锡矿物的新型捕收剂——苯乙烯瞵酸

在锡石浮选研究的工作中,近年来国际上对烷基及芳基膦酸的应用,得到了很大的重视。许多工作者认为烷基、芳基膦酸类化合物,对锡石具有良好的捕收作用,它的毒性小,价格较低,对锡石浮选,取得了良好的结果。其中以苯乙烯膦酸更便于工业生产。我们于1972年开展这方面的工作,合成了苯乙烯膦酸,1974年又完成了苯乙烯膦     

Physico-Chemical Factors Affecting the Separation of Cassiterite and Fluorite by Froth Flotation

Abstract

Cassiterite flotation is achieved industrially with some anionic collectors. However, the presence of fluorite in primary tin ores usually poses a problem in relation to the selectivity between the two minerals. In this work, a comparative study was undertaken involving adsorption, electrophoretic mobility and suspension stability measurements of both cassiterite and fluorite as a function of oleic acid concentration. These properties are discussed with reference to the calculated free energy of adsorption equation pending of oleic acid on the two minerals. Hallimond tube flotation tests conducted with the two minerals showed a distinctly higher floatability of fluorite at low oleic acid concentration. Micro-flotation studies using Procol CA-540. a sulphosuccinamate collector, presented similar results, indicating that fluorite can be floated selectively from cassiterite at low collector concentration and neutral pH.     

Investigating the use of an ionic liquid for rare earth mineral flotation

Common collectors for rare earth mineral(REM) flotation,which include carboxylates and hydroxamates,face problems such as being non-selective and sensitive to impurity ions.A type of ionic liquid(IL),tetraethylammonium mono-(2-ethylhexyl)2-ethylhexyl phosphonate([N_(222)][EHEHP]),has been investigated previously for rare earth elements(REE) solvent extraction,and was proven to be selective and effective.In this work,[N_(222)][EHEHP] was evaluated as a collector in bastnasite(a primary REM source for REE production) flotation for the first time.The results were compared with quartz and hematite,two common gangue minerals in REM deposits.Zeta potential measurements and Fouriertransform infrared spectroscopy(FT-IR) were completed to investigate the surface chemical properties involved in the flotation of these minerals using this collector.The findings were compared with microflotation results.FT-IR and zeta potential measurements suggest adsorption of the collector's phosphonate group onto bastn(a|")site and hematite,likely through chemisorption;whereas for quartz,the minimum micro flotation recovery is likely due to no adsorption of IL on its surface.Micro flotation re sults show higher collectability of [N2222] [EHEHP] for hematite than bastnasite,the latter only shows appreciable recovery at pH 5 with elevated dosage of IL(500 g/t).To achieve better separation,a two-stage flotation scheme was designed and evaluated by bench scale flotation on a synthetic mineral mixture.The concentrates and tails were analyzed by magnetic separation,and it is found that bastnasite recovery over 90% with maximum upgrade ratio 1.7 can be achieved with elevated collector dosage.     

Investigations on the Collector Reagent Development for the Recovery of Cassiterite from the Gravity Tails of a Low Grade Indian Tin Ore

Abstract

Results of the experimental studies carried out for developing a flowsheet for the recovery of cassiterite from the gravity tails of a low grade lode type tin ore (Tosham, Haryana) from India by froth flotation using three different collector reagents — alkyl phosphonic acid, sodium sulfosuccinamate and alkyl phosphoric acid ester are presented. The studies include micro-flotation of high purity cassiterite from Tosham, bench scale studies on gravity tails of Tosham tin ore, large scale semi-continuous test with relatively better reagent at optimised flotation conditions ending up with development of conceptual flowsheet meant for obtaining fuming grade cassiterite concentrate. The performance of various collector reagents was analysed on the basis of conventional metallurgical accounting methods and flotation kinetic rate constants. From a feed containing 0.24% Sn, a float product analysing 7% Sn with 55% recovery was obtained using a reagent combination of alkyl phosphoric acid ester-sodium silicofluoride - commercial grade sulfuric acid and citric acid.     

Mechanism of phthalic acid collector in flotation separation of fluorite and rare earth

The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions.The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement,the Fourier transform infrared(FT-IR),the X-ray photoelectron spectroscopy(XPS)and the stability constant measurement of active metal ion and phthalic acid coo rdination complex.According to the zeta potential testing results,the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which,in turn,increases its electronegativity and results in the motion of its potential.After the reaction between phthalic acid and fluorite ores under weakly acidic conditions,the peak of the fluorite ores is found to have significant changes in the FT-IR results,indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores.According to the XPS analysis,the peak of benzene ring of phthalic acid is as high as 2%on the surface of fluorite,while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite.According to the pH potentiometric titration results,the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant K’total of cerium phthalate complex,indicating that the complex generated between phthalic acid and Ca²⁺is more stable than the complex generated between phthalic acid and Ce³⁺.The possible reason is that Ca²⁺,with the highest reticular density,plays a prevailing role in the octahedron structure of fluorite amidst the acidic media.As the active point of flotation,Ca²⁺works with the carboxyl groups of the collector phthalic acid(-C=O-)to form polycyclic calcium phthalate complex.     

The effects of various activators on flotation performance of lime-depressed pyrrhotite

The effects of various activators on the flotation behaviour of lime-depressed pyrrhotite (FeS_1.1) were investigated. The activation mechanisms were studied using electrochemical analysis, Fourier transform infrared spectroscopy, zeta potential measurements, and X-ray photoelectron spectroscopy. Micro-flotation results showed that the floatability of pyrrhotite declined sharply from 97.6% to 5.1% with the addition of lime. The flotation performance improved with the addition of both acid and salt activators; oxalic acid was the best activator, with a recovery > 97.0%. Ca- and Fe-based hydrophilic films formed on the lime-depressed pyrrhotite surface, preventing the adsorption and oxidation of the collector on the pyrrhotite surface. The activator increases its own surface potential to prevent the production of hydrophiles, and also removed hydrophiles from the pyrrhotite surface. In addition, the oxalic acid formed a stable chelate and removed hydrophilic material from the pyrrhotite surface. This study contributes to understanding the flotation mechanism and activation of lime-depressed pyrrhotite.     

磨矿介质对典型硅酸盐矿物浮选的影响及机理

研究在湿式磨矿条件下,十二胺和油酸钠作为捕收剂时,锆球和铁球作为磨矿介质对典型硅酸盐矿物浮选的影响。通过对矿物表面动电位和X射线光电子能谱检测,分析磨矿介质对硅酸盐矿物浮选影响的机理。研究表明:十二胺作为捕收剂,低于最佳浮选pH值时,锆球湿磨锆英石、绿柱石、锂辉石和石英的浮选回收率均高于铁球湿磨,pH值继续升高,锆球湿磨和铁球湿磨这四种硅酸盐矿物的浮选回收率相近；在pH值2~12范围内,锆球湿磨和铁球湿磨长石的浮选回收率相近；油酸钠作为捕收剂,相同pH值条件下,锆球湿磨锆英石、绿柱石、锂辉石、长石和石英的浮选回收率大多低于铁球湿磨。检测结果表明:锆球湿磨时,低于最佳浮选pH值条件下,锆英石、绿柱石、锂辉石和石英表面电位低于铁球湿磨,因而十二胺作为捕收剂时这四种矿物的浮选回收率高于铁球湿磨；铁球湿磨时,油酸钠作为捕收剂,锆英石、绿柱石、锂辉石、长石和石英表面Fe含量明显增加,对这五种矿物起到活化作用,因而浮选回收率高于锆球湿磨。      

Synergistic depression mechanism of Ca2+ ions and sodium silicate on bastnaesite flotation

Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation. Sodium silicate is commonly used to depress calcium-bearing gangue minerals, however it can also depress bastnaesite when Ca²⁺ ions exist in the pulp. In this study, the effect of Ca²⁺ ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation, zeta potential, fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. Micro-flotation results show that the combination of Ca²⁺ ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect. Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly. Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely. XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO₃ precipitate, which causes more serious depression on bastnaesite flotation.     

羟肟酸类捕收剂性质及浮选钨矿物特性

通过对羟肟酸类捕收剂性质和羟肟酸类捕收剂与钨矿物作用特性的描述,表明羟肟酸浮选钨矿物最佳pH在pKa附近,此时药剂吸附量最大,ζ电位更负,羟肟酸与矿物表面金属或金属离子羟基化合物发生螯合反应。同时吸附试验结果表明羟肟酸在钨矿物表面的吸附主要为化学吸附,同时存在不均匀、物理吸附,最终形成多层吸附。     

Effects of Calcium and Chloride Ions in Iron Ore Reverse Cationic Flotation: Fundamental Studies

ABSTRACT

In this work, the simultaneous effects of Ca²⁺ and Cl^? ions in an aqueous solution at pH 10.5 on the flotation of quartz (the main impurity in itabiritic iron ore) and hematite by starch and amine was investigated. A strong depression in the flotation of both quartz and hematite conditioned with CaCl₂ was observed. This effect was higher for hematite than for quartz. Based on zeta potential measurements and the speciation diagram of calcium in aqueous solutions, the physical adsorption of Ca²⁺ on the surfaces of both minerals was inferred. The infrared spectrum of quartz conditioned with CaCl₂ at pH 10.5 was similar to its reagent-free reference spectrum. However, a new band at the wavenumber of 1465 cm^?1 was identified in the spectrum of hematite conditioned with CaCl₂; this band did not exist in its reference spectrum. This new band may indicate the chemical adsorption of Cl^? ions on the hematite surface. The complexation of Ca²⁺ by ethylenediaminetetraacetic acid enabled complete quartz recovery with amine. For hematite, recovery was partially restored, probably because of the positive chloro-complexes on the hydrated iron surfaces of hematite, which prevented the adsorption of aminium ions at these sites. Therefore, the selective inverse cationic flotation of itabiritic iron ore at pH 10.5 in water containing Ca²⁺ is possibly only after complexing them with EDTA.     

从超细粒高铅锌氰化尾渣中浮选回收有价金属的试验研究

从超细粒氰化尾渣中回收有价元素是浮选中的难题,目前采用的方法主要是先加入氧化剂预处理脱氰,再加入捕收剂浮选。然而,该工艺存在药剂成本高、氰化物无法循环使用及矿物表面二次氧化等问题。以山东某高铅锌氰化尾渣为研究对象,在不脱氰的条件下,以氰化贫液为浮选用水,通过浮选试验和闭路试验等方法研究氰化尾渣的浮选回收效果。试验结果表明,在不脱氰的条件下,可浮选回收铅锌,铅精矿铅品位为56.61%,回收率为89.04%;锌精矿锌品位为32.6%,回收率为74.5%。SEM显微镜研究表明,铅精矿中铜矿物表面包裹一层小颗粒方铅矿,改变了黄铜矿界面性质,使得铜矿物表面特性趋于方铅矿界面性质,导致铜矿物大部分进入铅精矿中。