β-环糊精光度法测定捕收剂在煤表面的吸附量

在等温条件下,将有机染料对疏水性浮选捕收剂进行染色,利用β-环糊精内部具有疏水性,腔外羟基具有亲水性的特点。染色后的浮选捕收剂进入β-环糊精主体的疏水部分形成有色的主-客体包合物,此包合物的消光值与捕收剂的浓度成比例关系,因而可用分光光度法测定浮选残余液中捕收剂的浓度,进而可得到浮选捕收剂在煤表面的等温吸附量。实验结果表明：应用该种方法测定的等温吸附量数值与射线浓度计法测定的吸附量数值相吻合,为捕收剂在煤表面等温吸附量的测定又提供了一种方法。     

磷块岩浮选新捕收剂CCLS

开发新型高效浮选药剂是提高分选指标、降低精矿成本的有效途径。CCLS的研制成功,可以加速磷块岩矿石的开发和利用。 一、新型捕收剂的构思 1、国内外研究实践表明,两种或两种以上捕收剂混用会产生协同效应。由于矿物在成矿或破碎过程中表面的不均匀性,对同一捕收剂也有不同的吸附能力;而不同的捕收剂对表面状态相似的矿物也有不同的吸附能力。因此,如果将两种或两种以上相互匹配的捕收剂混用,则有可能获得矿物浮游所需的最佳吸附密度和强度。使在矿物表面的物理吸附和化学吸附兼而有之,获得更佳的浮选捕收性和选择性。     

红外光谱法测定捕收剂在磷矿表面的吸附量

以油酸钠、工业磷矿浮选捕收剂YP6-6为研究对象,使用红外光谱法测定其在磷矿表面的吸附量。试验结果表明,三波长红外光谱法不仅可以测定单一有机捕收剂油酸钠在磷矿表面的吸附量,还可以测定复杂复配有机捕收剂YP6-6在磷矿表面的吸附量,具有波数定位准确、操作简单、测定快速等特点。     

新型脱镁捕收剂FC-2B浮选云南海口磷矿试验研究

针对云南海口磷矿进行了分离胶磷矿和白云石的浮选试验研究,实际矿物浮选试验结果表明,FC-2B捕收剂能有效分选胶磷矿与白云石。在入选原矿P2O5品位为19.16%,MgO质量分数为4.67%的情况下,获得的磷精矿P2O5品位为28.54%,回收率为80.40%,MgO质量分数为0.80%,MgO排除率为90.52%。纯矿物试验研究了FC-2B捕收剂对胶磷矿和白云石选择性的差异,并借助红外光谱测试证明该捕收剂在白云石表面主要为牢固的化学吸附,其对白云石表现出较好的选择性。     

脂肪酸与磷灰石吸附机理及其在磷矿选矿中的应用

对脂肪酸与磷灰石吸附机理及在磷矿选矿中的应用进行了介绍。碱性pH脂肪酸与磷灰石的吸附以化学吸附为主,而在较低的pH值两者的吸附即存在化学吸附又存在物理吸附。不饱和酸含量较高的脂肪酸有利于磷灰石的浮选。对脂肪酸进行改性和组合用药可以明显提高其浮选特性。对脂肪酸的改性多以α-C取代基化,异极性化等手段合成具有多官能团的脂肪酸类捕收剂;而组合用药常将脂肪酸类捕收剂和其他类型捕收剂或表面活性剂组合应用。     

浮选捕收剂吸收性能研究

煤炭洗选加工是提高煤炭综合利用价值的有效途径,煤炭分选本身如浮选煤需要研究捕收剂、起泡剂、促进剂等浮选药剂性能,以降低精煤灰分、提高精煤产率、改善浮选效果。而在浮选原矿中加入浮选捕收剂可改善煤粉表面疏水性,促进捕收剂在煤炭表面的吸附,可见吸附是其间相互作用的一种主要形式。     

浮选捕收剂吸收性能研究

煤炭洗选加工是提高煤炭综合利用价值的有效途径，煤炭分选本身如浮选煤需要研究捕收剂、起泡剂、促进剂等浮选药剂性能，以降低精煤灰分、提高精煤产率、改善浮选效果。而在浮选原矿中加入浮选捕收剂可改善煤粉表面疏水性，促进捕收剂在煤炭表面的吸附，可见吸附是其间相互作用的一种主要形式。     

胺类捕收剂在磷矿脉石石英反浮选中的应用及机理

对三种新型阳离子胺类捕收剂605G83、605G91和605G94在磷酸盐矿石反浮选去除脉石石英中的浮选性能进行了研究,用石英晶体微天平(QCM-D)结合Zeta电位研究了三种捕收剂在石英表面的吸附机理。结果表明,当pH为7,捕收剂用量为1.0 kg/t,605G83的正浮选效率最高,可达到88.4%,A.I.为10.1%。此外,采用605G83和605G91作为捕收剂在低药剂用量且不需调pH值的条件下就可以达到605G94在1.0 kg/t和pH=9时的捕收性。Zeta电位测定结果表明,与三种胺作用后石英的表面电位升高,且零电点向pH高于2的方向移动。QCM-D测定结果显示605G83、605G91比605G94更易在石英表面形成规则、牢固且吸附密度高的吸附层,使石英表面的疏水性更强,从而得到更好的浮选效果。此外,研究结果也证实了QCM-D在表面吸附机理研究中的高效性和精确性。     

一种新型螯合剂在铝土矿浮选分离中的应用

合成了含有单羧基和双羟肟基的新型螫合捕收剂HAD。研究了其对一水硬铝石和铝硅酸盐矿物的浮选行为及浮选机理。结果表明,该捕收剂在中性条件下能有效分离一水硬铝石与铝硅酸盐矿物。作用机理可能是HAD中-COOH和-CONHOH的O原子之间协作与一水硬铝石表面Al点形成螯合物而发生化学吸附,在铝硅酸盐矿物表面主要发生的是物理吸附。     

复合捕收剂协同作用机理研究

采用苯乙烯膦酸与脂肪醇组成的复合捕收剂浮选金红石矿取得了较好效果，通过改进的Ｈａｌｌｉｍｏｎｄ管浮选试验、吸附量测定试验、捕收剂溶液表面张力和金红石表面接触角的测量以及Ｘ射线光电子能谱测试（ＸＰＳ），详细研究了复合捕收剂的协同作用机理。试验结果表明：苯乙烯膦酸在金红石表面发生了化学吸附，脂肪醇与苯乙烯膦酸相互联结，其疏水基指向水相，从而增强了金红石表面的疏水性，提高浮选结果。     

Correlation between surface free energy and floatability of galena with potassium ethyl xanthate

From the maximal extrapolated film pressure π_max values for n-octane and n-propanol, the dispersion and non-dispersion components of the surface free energy of galena precoated with potassium ethyl xanthate (collector) were estimated and they were then correlated with the floatability of galena. The collector layer deposited by methanol evaporation did not produce any significant changes in the surface free energy of galena. Polymolecular adsorption of the collector occurred from aqueous solution. The adsorbed collector layer of ~8 statistical monolayers in thickness produced a considerable decrease in the dispersion component of the surface free energy and complete disappearance of non-dispersion interactions. At this surface coverage, a certain change in the properties of the adsorbed layer appeared which was probably connected with the formation of polymolecular layers containing dixanthogen. The work of the water adhesion being significantly lower than the work of water cohesion appeared insufficient to achieve a high floatability of galena.     

Interactions Between Sodium Oleate and Polyoxyethylene Ether and the Application in the Low-Temperature Flotation of Scheelite at 283 K

The poor collecting performance of fatty acids at low temperatures is a problem in mineral flotation. In this study, the floatability of scheelite at 283 K was studied using sodium oleate and binary mixtures of sodium oleate and lauryl alcohol polyoxyethylene ether (MOA-9) as the collector, and interactions between the two surfactants at 283 K were investigated by the means of surface tension and steady state fluorescence measurements. The flotation experiment results show that the collecting performance of the mixed anonic/nonionic collector is stronger than that of single surfactant, and the best molar ratio of sodium oleate to MOA-9 is 10:1 at pH 10. The surface tension results show that the critical micelle concentration value of sodium oleate, MOA-9 and the binary solution is about 2 × 10^?4, 2.5 × 10^?4, and 1.2 × 10^?4 mol/l, respectively. Compared with single surfactants, the mixture exhibits better surface activities since it is more efficient at decreasing the air–water surface tension. The steady state fluorescence results indicate that the hydrophobic parts of MOA-9 molecules insert into the hydrophobic region of sodium oleate micelles to form larger and less compact mixed micelles. The decrease in zeta potential of scheelite treated with the mixed collector indicates the presence of MOA-9 can enhance the chemical adsorption of sodium oleate on the scheelite surface. Therefore, the mixed anonic/nonionic collector can enhance the flotation behavior of scheelite at 283 K.     

The investigation of the floatability improvement of Yozgat Ayr?dam lignite using various collectors

In this study, the floatability of Yozgat Ayr?dam lignite using kerosene, kerosene+emulsifier and kerosene+emulsifier+surfactant has been investigated. It was determined that the combination of both kerosene+emulsifier and kerosene+emulsifier+surfactant were stable (except anionic), easily dispersible in water and formed very small oil droplets compared to the kerosene. It was concluded that all of the collectors except kerosene investigated in this study increased the floatability of Yozgat Ayr?dam lignite. However when the combustible recovery and flotation efficiency index were considered, the best results were obtained from the combination of both keresone+Acorga M5640 and keresone+Acorga M5640+Flotigol CS (non-ionic). It was based on the high binding and spreading tendency of both collectors over the coal surface.The concentrates having a relatively low ash content were obtained with the kerosene+Acorga M5640+Flotigol CS. Consequently, the floatability improvement of Yozgat Ayr?dam lignite was achieved by using the combination of both kerosene+emulsifier and kerosene+emulsifier+surfactant.     

金红石与磷灰石浮选分离中硫酸铝的作用研究

研究表明．在FL108作捕收剂条件下，硫酸铝强烈抑制金红石而使磷灰石上浮，采用“FL108＋Al2（SO4）3”的浮选药剂制度，可实现两矿物的分离。通过分析Al3＋和金红石表面Ti4＋、磷灰石表面Ca2＋的水解特性，还阐述了Al2（SO4）3的选择抑制机理。     

Enhancement in hydrophobicity of low rank coal by surfactants — A critical overview

The flotation of fine (− 0.5 mm) low rank or oxidized coal is difficult to achieve with the common coal flotation collectors like kerosene, fuel oil or diesel oil (oily collector). The presence of small amounts of oxygen is enough to cause oxidation. The oxidation of coals starts with the physical adsorption of oxygen on the surface to form an oxycomplex followed by chemical adsorption of oxygen to form polar phenolic-OH, carbonyls, phenols and peroxide type oxygenated moieties by the rupture of cyclic rings. The addition of promoter, surfactant or oxygenated functional groups to the collector molecule markedly enhances the flotation of lower rank and oxidized coals due to the hydrogen bonding with the polar part of the coal surface and the reagent. The performance of these reagents is compared with that of oily collectors, namely kerosene, dodecane, nonylbenzene and polar part of the surfactant having an oxygen atom. The mode of addition of non-ionic surfactant with oily collector also has a major role in the flotation response. The addition of non-ionic surfactant after the oily collector has shown a positive effect on yield and grade.     

矿浆中金属离子对硅线石与石英浮选分离的影响

系统研究了Fe^3 和Al^3 等金属离子对硅线石和石英可浮性的影响，结果表明：采用油酸钠为捕收剂，Fe^3 和Al^3 在中性或弱碱性介质中对石英浮选有很强活化作用，从而使硅线石和石英浮选分离困难，柠檬酸对金属离子活化石英有很强抑制作用，而对硅线石抑制作用较弱，是浮选分离硅线石和石英较好的的选择性抑制剂，Auger电子能谱仪测试表明：柠檬酸在硅线石表面作用前后Al峰的化学位移为-0.1eV，化学作用很弱，而在Fe^3 和Al^3 离子活化的石英表面，加入柠檬酸前有明显Al Auger电子能峰，加入后，石英表面Al Auger电子能峰消失，表明柠檬酸加入促使吸附在石英表面Al^3 离子溶解，使石英表面阴离子捕收剂吸附活性点降低。     

Removal of Copper from Aqueous Amminecopper(II) Solution by Foam Flotation

Abstract

Copper is removed from aqueous amminecopper(II) solution by adsorbing colloid flotation. Iron(III) hydroxide is used as the adsorbing carrier floc, and an anionic surfactant sodium dodecyl sulfate is used as the collector. Optimal flotations are achieved at the pH of maximum adsorption of copper on the resultant flocs. Adsorption of copper on the flocs enhances their floatability. Rapid and efficient removal of copper can be obtained by a batch operation under controlled dosing of iron(III) for samples in various concentrations of total ammonia. A two-step batch method has the advantages of higher efficiency and lower copper residue when dealing with samples of high copper concentration (>200 ppm) and low total ammonia (<0.15 M).     

The surface oxidation of pyrite in alkaline solution

The collector-less flotation of pyrite has been studied by conventional techniques and is correlated to the electrochemical behaviour of pyrite in alkaline solution (1m NaClO₄, pH 11). It was concluded that the initial oxidation of pyrite produces a hydrophobic sulphur rich surface together with hydrophilic iron hydroxide species. Also upon grinding, the surface is covered by hydrophilic species and therefore no significant flotation was obtained in the absence of a collector. However, collectorless flotation was readily obtained in an iron complexing solution like EDTA. This indicates that the remaining sulphur-rich layer is responsible for the floatability of pyrite under these conditions.     

The flotation behavior of coal-pyrite in high-sulfur coal

ABSTRACT

The properties and flotation behavior of coal-pyrite were analyzed by the contact angle, induction time, and flotation tests. The results indicate that compared with coal, coal-pyrite has a smaller contact angle and longer induction time. The floatability of coal-pyrite is poor with dodecane as the collector. A part of fine liberated pyrite mixed with the clean coal in flotation. The linear relationship between the ash and liberated pyritic sulfur recoveries implies the same recovery mechanism, that is, mechanical entrainment. Molecular dynamics simulation also demonstrates that dodecane could not break through the hydrated film to be absorbed on the pyrite surface.