SF浮选分离萤石与重晶石的作用机理

为了获得具有高度选择性的抑制药剂抑制重晶石浮游以获得优质萤石产品,通过光电子能谱测试分析、红外光谱分析和浮选试验,对抑制剂NAS（Na2SO4水溶液）和HDF（苛性淀粉）与重晶石的作用机理进行了研究,结果表明,NAS对重晶石的抑制作用机理是NAS中的SO^2-4在重晶石表面发生定位吸附,抑制作用具有秀好的选择性;HDF对重晶石的抑制作用机理是HDF分子在重晶石表面发生了化学吸附,当HDF用量大时也会抑制萤石上浮。同时,将NAS和HDF按一定比例混合作为一种新型调整剂,用SDF表示,研究表明,SDF对重晶石的抑制作用是NAS和HDF抑制作用的加和．SDF对重晶石具有很强的抑制作用,且抑制作用具有高度选择性。     

不同模数水玻璃对白钨矿浮选行为的影响

为探究不同模数硅酸钠(俗称水玻璃)对白钨矿、萤石和方解石浮选行为的影响,首先进行了单矿物浮选试验,然后采用Zeta电位测试、红外光谱(FTIR)和浊度分析手段,对水玻璃选择性抑制萤石和方解石的抑制机理进行了研究.浮选试验表明：水玻璃模数越大,抑制性能越强,选择性也越差.模数为2.5的水玻璃试验效果最佳,在室温为15℃,pH值为10,捕收剂DYS-W19用量为15 mg/L,水玻璃(模数2.5)用量为700 mg/L的条件下,白钨矿、萤石和方解石的回收率分别为84.12%,10.55%和9.85%.Zeta电位测试和FTIR分析表明水玻璃(模数2.5)可以选择性地吸附在矿物表面,减少了萤石和方解石表面上捕收剂的吸附,但对白钨矿影响较小.浊度试验结果表明：水玻璃模数越大,生成硅酸胶体和硅酸钙等亲水性沉淀速率也越快.     

SO_2气氛下半焦负载Na,Ca,Fe对NO-半焦还原反应的影响

通过程序升温实验和暂态响应实验 ,研究了 SO2 气氛下半焦负载 Na,Ca,Fe对 NO-半焦还原反应的影响 ;结果表明 SO2 对 NO-半焦反应的影响因温度高低而不同 ,低温下由于 SO2 在半焦表面的化学吸附占据了半焦表面的活性位 ,因而抑制 NO的还原 ,高温则有利于 SO2 - NO气相反应 ,从而致使 NO转化率升高 ;SO2 对 NO-负载催化剂半焦还原反应有抑制作用 ,其抑制程度与温度有关 ,低温下随温度升高 ,抑制程度增加 ,高温下随温度升高抑制程度降低 ;负载 Na,Ca和 Fe的半焦在 SO2 气氛下对 NO-半焦还原反应表现为不同的活性 ,其中 Fe的活性最高 ,Na的活性受 SO2 影响最大 ,这与硫酸盐的分解温度以及 SO2 在半焦表面化学吸附性质有关 .     

SO_2对Fe-Mo/ZSM-5催化剂上NO_x催化还原性能的影响

分别采用共浸渍法和气相离子交换法制备了Fe-Mo/ZSM-5(CI)和Fe-Mo/ZSM-5(VIE)样品,研究了SO2对Fe-Mo/ZSM-5催化剂上以NH3为还原剂的NOx-SCR反应的影响.同时利用暂态响应实验、SO2-TPD以及FT-IR等技术对SO2的影响行为进行了分析.结果发现,VIE样品较CI样品具有更好的SCR催化活性.SO2只在低于300℃时对Fe-Mo/ZSM-5催化剂的活性有影响,而在高于300℃对催化活性几乎没有影响,而且温度越高,SO2对催化剂活性的抑制作用越小.研究表明,SO2在低温下对催化活性的抑制作用主要来源于其在催化剂表面的吸附作用,SO2在催化剂表面形成吸附态SO2-4离子,少量的硫酸盐沉积在催化剂表面,减少了催化剂表面活性中心的数量.     

SO2气氛下半焦负载Na,Ca,Fe对NO—半焦还原反应的影响

通过程序升温实验和暂态响应实验，研究了SO2气氛下半焦负载Na,Ca,Fe对NO-半焦还原反应的影响；结果表明SO2对NO-半焦反应的影响因温度高低而不同，低温下由于SO2在半焦表面的化学吸附占据了半焦表面的活性位，因而抑制NO的还原，高温则有利于SO2-NO气相反应，从而致使NO转化率升高；SO2对NO-负载催化剂半焦还原反应有抑制作用。其抑制程度与温度有关，低温下随温度升高；抑制程度增加，高温下随温度升高抑制程度降低；负载Na,Ca和Fe的半焦在SO2气氛下对NO-半焦还原反应表现为不同的活性，其中Fe的活性最高，Na的活性受SO2影响最大，这与硫酸盐的分解温度以及SO2在半焦表面化学吸附性质有关。     

天然锰矿对水体中磷的去除研究

研究了天然锰矿对水体中磷的去除效果,考察了温度、光照、锰矿用量、溶液pH及共存离子对除磷效果的影响。结果表明,pH对磷的吸附影响很大。离子影响中,Ca2+、Mg2+、CO32-、HCO3-、SiO32-和SO24-的影响不大,而AsO43-和AsO3-却能明显抑制锰矿对磷的吸附。Freundlich等温吸附模型(r2=0.984 4)能很好的描述磷的吸附。动力学数据符合二级动力学模型(r2=0.999 9),最大吸附量为30.40μg/g。FTIR和SEM结果显示磷主要是通过与锰矿表面的羟基发生置换或生成内层络合物而被吸附。天然锰矿,具有较大的比表面积,强选择性,是一种很有前景的去除天然水体中磷的吸附剂。     

六偏磷酸钠在铝土矿浮选中的作用

通过浮选试验、吸附量测试、动电位测试,研究了六偏磷酸钠对一水硬铝石和高岭石2种矿物浮选行为的影响以及其作用机理。结果表明：六偏磷酸钠对这2种矿物均有抑制作用,当捕收剂量增大时,被六偏磷酸钠抑制的一水硬铝石的可浮性逐渐变好,而高岭石则变化不大。其主要原因在于六偏磷酸钠与捕收剂油酸钠在这2种矿物表面存在竞争吸附,而油酸钠在一水硬铝石表面的吸附能力强于在高岭石表面的吸附,使得在一定捕收剂用量下,六偏磷酸钠抑制高岭石的上浮而不抑制一水硬铝石。这为2种矿物浮选分离提供了依据;此外,六偏磷酸钠对矿物表面的动电位影响较大,增大了矿物之间的静电排斥力,有利于矿泥的分散,增强了浮选分离的选择性。     

新型三唑衍生物作为20g钢的H2SO4酸洗缓蚀剂作用机理的研究

采用失重法、电化学方法研究新型三唑衍生物在1mol／L H2SO4中缓蚀性能和机理,并研究该缓蚀剂在20g钢表面的吸附行为。结果表明．新型三唑绥蚀剂是一种混合型缓蚀剂,在1mol／L H2SO4溶液中缓蚀剂浓度为1000g／L时缓蚀率最高,为94．6％。Matlab拟合表明该缓蚀剂在20g钢表面的吸附行为符合Bockris-Swinkels吸附等温式。     

添加剂对低镍高铁红土镍矿选择性还原的影响

采用还原焙烧-磁选法处理低镍高铁型红土镍矿,研究了添加剂(Na2SO4,Na2CO3,CaCO3和CaSO4)对镍、铁矿物选择性还原的影响规律,并通过X射线衍射(XRD)、扫描电镜-能谱分析等方法,分析了添加剂作用下焙烧矿中矿物成分、相变转化、微观结构特征及元素赋存状态.结果表明:添加剂Na2CO3,CaCO3及CaSO4作用下选择性还原效果较差,而Na2SO4作用效果明显,在Na2SO4用量10%,烟煤用量2%,1 250℃焙烧50min条件下,获得镍铁产品中镍的品位为9.52%,镍回收率88.40%,镍铁回收率之差达60.50%,实现了镍铁矿物的选择性还原,其原因是Na2SO4作用下弱还原气氛抑制了浮氏体还原成金属铁,降低了铁的回收率,同时Na2SO4分解出的S降低了镍铁颗粒的表面能和熔点,而且焙烧矿呈熔融状态,促进了镍铁颗粒长大,有利于镍铁颗粒与脉石矿物充分分离.     

SO_4~(2-)/TiO_2固体超强酸的制备及用于催化酯化反应的研究

用两相滴定沉淀法制备了SO4（2-）／TiO2固体超强酸，透射电镜表征为超细粒子。分别用于氯乙酸酯、马来酸酯、丙烯酸酯的合成，具有较高的催化活性。对酯化反应的活性主要是B酸中心，其选择性要求B酸和L酸有一最佳协同作用。对该催化剂的使用寿命及再生进行了研究，认为不饱和羧酸在固体超强酸表面的强吸附及由此引起的失硫是催化活性降低的主要原因。     

新型抑制剂在铜铅浮选分离中的应用

用一种工业副产品为原料合成了多羟基硫代磷酸盐抑制剂．浮选试验表明其对方铅矿有较强的选择抑制作用,抑制效果优于重铬酸钾,是铜铅混合精矿浮选分离的一种比较理想的抑制剂．     

黄铁矿浮选中抑制剂WHL-Y1降镁的作用机理

在黄铁矿浮选中,使用抑制剂WHL-Y1可有效地降低精矿中MgO含量.通过工艺矿相研究及吸附量、Zata电位、红外光谱测定,研究了WHL-Y1的作用机理：WHL-Y1中的-P-OH离子可以与矿物表面的Mg^2＋（Ca^2＋）发生化学反应,增强不纯黄铁矿的亲水性,在浮选时使其受到抑制,较纯黄铁矿可以优先浮选分离.     

Effect of organic depressant lignosulfonate calcium on separation of chalcopyrite from pyrite

In order to selectively separate chalcopyrite from pyrite, the effect of organic depressant lignosulfonate calcium (LSC) on the flotation separation of chalcopyrite from pyrite was investigated by flotation tests. The depression mechanism was studied by Fourier-transform-infrared (FTIR) analysis. The flotation tests of single mineral show that LSC can depress the flotation of pyrite in a certain pH range, but it has little effect on chalcopyrite flotation. Flotation separation of a mixture of chalcopyrite and pyrite can be completed to obtain a copper concentrate grade up to 24.73% with a recovery of 80.36%. IR analysis shows that LSC and butyl xanthate compete in absorption on pyrite surface, and there exists an LSC characteristic peak on pyrite surface. There is little adsorption of LSC on chalcopyrite.     

Fourier Transform Infrared Spectroscopic Studies in Flotation

Fourier transform infrared (FTIR) spectroscopy has been extensively employed In flotation research. The work done by the author and co-workers has been reported. A comparison has been made among the different FTIR specfroscopic techniques, e.g. , transmission FTIR spectroscopy, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and attenuated total reflectance (ATR) FTIR spectroscopy. FTIR spectroscopy has been used to study the mechanism of interaction between the collector and the surfaces of different minerals, the mechanism of action of the depressant in improving the selectivity of flotation, and the mechanism of adsorption of the polymeric modifying reagent on mineral surfaces. The interaction between particles in mineral suspension has also been studied by FTIR spectroscopy.     

Effect and mechanism of siderite on reverse anionic flotation of quartz from hematite

Reverse flotation technology is one of the most efficient ways to improve the quality and reduce impurity of iron concentrate. Mineral processors dealing with hematite face a challenge that the flotation results of reverse flotation of hematite are poor in presence of siderite using fatty acid as collector, starch as depressant of iron minerals and calcium ion as activator of quartz at strong alkaline pH. In this work, the effect of siderite on reverse anionic flotation of quartz from hematite was investigated. The effect mechanism of siderite on reverse flotation of hematite was studied by solution chemistry, ultraviolet spectrophotometry(UV) and Fourier transform infrared spectroscopy(FTIR). It was observed that siderite had strong depressive effect on quartz in flotation using sodium oleate as collector, corn starch as depressant of iron minerals and calcium chloride as activator of quartz at strong alkaline pH. The starch was adsorbed onto calcium carbonate by chemical reaction which was formed by CO~(2-)_3 from siderite dissolution and Ca~(2+) from calcium chloride as activator of quartz and precipitated on the surface of quartz, which resulted in improving the hydrophilic ability of quartz.     

辛基羟肟酸浮选行为的研究进展

羟肟酸是一类高效、低毒、选择性强的捕收剂,已被广泛应用于多种金属矿,特别是稀土矿物的浮选。其中,辛基羟肟酸（OHA）碳链长度适中,生产工艺简单且成本低,具有良好的浮选性能和起泡性能。介绍了OHA的合成方法、捕收机理、分析检测手段及其在稀土矿物、钨矿物、铁矿物、锡石、孔雀石等矿物浮选中的应用。OHA可通过络合作用与多种金属离子形成稳定的杂环螯合物,从而实现药剂在矿物表面的选择性吸附。OHA浮选pH范围较宽,pH为7左右浮选效果最佳。在抑制剂的作用下,OHA能实现稀土矿物、钨矿物等有价矿物与重晶石、萤石、石英等脉石矿物的有效分离。开发基于OHA 的组合药剂,有望获得更好的选别指标和经济效益。     

SURFACE CHEMICAL CHARACTERISTICS AND FLOATION SEPARATION OF WOLLASTONITE AND GARNET

In order to nealize the efficient floatation separation ofgarnet and wollastonite,the authors studied the surface chemical charac-teristics and various floatation behaviour of the two minerals,developedacidic combination depressant FD_1 and introduced sodium oleate,FeCl_3 andFD_1 as the flotation agent,they achieved success.In the experimental re-search on the artificiallymixed ores separation,the recovery and concentra-tion grade of the two minerals were both over 92% and 95% respectively.At the same time,it was found that the chemical absorption form of ironoleate presented bridge and chelating patterns on the surfaces of garnetand wollastonite activated by Fe~(3+).     

Effect and mechanism of dolomite with different size fractions on hematite flotation using sodium oleate as collector

The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigated by means of solution chemistry, ultraviolet spectrophotometry(UV), inductively coupled plasma atomic emission spectrometry(ICP-AES) and X-ray photoelectron spectroscopy(XPS). It is observed that dolomite with different size fractions has depressing effect on hematite flotation using sodium oleate as collector, and dolomite could be the "mineral depressant" of hematite using sodium oleate as collector. The reasons for that are concerned with sodium oleate consumption and the adsorption onto hematite of dissolved species of dolomite.     

KMnO4/NaOH溶液吸收SO2/NO的动力学研究

在典型湿法烟气脱硫系统运行条件下,研究了平面传质搅拌反应器中KMnO₄/NaOH溶液同时吸收SO₂和NO的动力学,确定了反应级数、反应速率常数以及活化能.实验结果表明,NO的吸收速率随着入口NO分压和KMnO₄浓度的增加而提高.在吸收剂溶液中加入NaOH可以提高NO的吸收速率,烟气中O₂的体积分数对于NO和SO₂的吸收速率几乎没有影响.当同时吸收烟气中的SO₂和NO时,SO₂会降低NO的吸收速率,而NO对SO₂的吸收速率几乎没有影响.在KMnO4/NaOH溶液中NO的吸收速率对NO相间浓度和KMnO4浓度均为一级反应,平均反应速率常数为5.79×103 m³/(mol•s),活化能为26.85 kJ/mol.     

Depression behaviors of N-thiourea-maleamic acid and its adsorption mechanism on galena in Mo-Pb flotation separation

In present study, a novel organic depressant N-thiourea-maleamic acid (TMA) was synthesized and applied as a galena depressant in the flotation separation of Mo-Pb ores. The depression behaviors of TMA were tested through flotation experiments. A wider separation window for single minerals over 90.0% was obtained at 30.0 mg/L TMA, confirming that TMA could depress galena significantly, while effected molybdenite floatability slightly. An effective separation was obtained for artificially mixed minerals and actual Mo-Pb ores. The adsorption mechanism on galena was revealed by UV–Vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR) analysis, contact angle tests and X-ray photoelectron spectroscopy (XPS) analysis. The zeta potentials of galena became more negative and the contact angle of galena dropped from initial 74.36° to 57.8° with 30.0 mg/L TMA depressant, inferring that TMA had adsorbed on galena surface. The analysis results of UV–Vis spectra, FT-IR and XPS gave further evidence that TMA might chemisorb on galena surface via Pb sites on galena surface and the thiourea group in TMA molecular structure, while the carboxyl group played a role of hydrophilicity.