矿物表面金属离子组分与糊精的相互作用（Ⅰ）──糊精在矿物表面的吸附

通过矿物表面糊精吸附量的测定、电动电位测定及在不同ｐＨ值下矿物表面羟基浓度的测定，系统探索了糊精在赤铁矿、金红石、方解石、萤石、重晶石、磷灰石及硅灰石等氧化矿和盐类矿物表面附吸的规律，发现糊精的吸附主要是由于与矿物表面金属羟基化合物发生了程度不同的化学作用。     

矿物表面金属离子组分与糊精的相互作用（Ⅲ）──糊精存在时萤石／方解石、萤石／金红石的浮选分离

通过系统分析糊精在萤石、方解石和金红石表面吸附特性、作用形式及键合机理等方面的差异，发现在不同ｐＨ值区间上述矿物与糊精作用行为不同。在加入糊精时，通过控制矿浆ｐＨ值，能进行萤石／方解石、萤石／金红石的浮选分离。     

矿物表面金属离子组分与糊精的相互作用（Ⅱ）──糊精在氧化矿及盐类矿物表面吸附的XPS及AES研究

借助于光电子能谱（ＸＰＳ）及俄歇电子能谱（ＡＥＳ）测试，系统地研究了糊精在氧化矿及盐类矿物表面的作用行为．发现糊精在赤铁矿、金红石、方解石和重晶石表面作用前后晶格金属元素键合状态发生了显著变化，其本质为化学作用，而糊精在萤石表面作用前后，Ｃａ的结合能及俄歇参数变化较小，化学作用较弱，更接近于氢键等物理作用。     

萤石、重晶石和方解石的可浮性研究

本文通过试验研究了萤石、重晶石和方解石的可浮性与捕收剂油酸用量及PH值的关系。试验发现浮选萤石、重晶石,方解石所需要的油酸用量不同,次序为：萤石＜重晶石＜方解石。萤石和重晶石在PH为中性左右时可浮性最好,而方解石在强碱性条件下可浮性最好。本文还通过矿物表面电性状态等探讨了油酸捕收萤石、重晶石和方解石的作用机理。     

萤石与重晶石浮选分离新药剂的研究

萤石与重晶石的浮选分离及药剂的作用机理研究结果表明,烷基α-羟基1.1双膦酸(TF28)是萤石和重晶石的优良捕收剂。以ND_(16)作抑制剂,可以实现萤石与重晶石的浮选分离。TF28在萤石、重晶石表面除存在化学吸附外,在重晶石表面还存在物理吸附。     

细重晶石的浮选研究

对重晶石的浮选研 究,曾研究了油酸钠对 重晶石的吸附机理,及 以油酸钠为捕收剂时重晶石的浮游性。试验中将重晶石与地开石(一种高岭土矿物)以1:1的混合样进行浮选分离,并对深泽选矿厂经水力旋流器分级的细重晶石进行浮选回收,均取得研究成果。 ①据油酸钠对重晶石的吸附机理,在矿浆浓度低时,因油酸离子和硫酸离子的交换吸附,在矿物表面形成油酸钡化学吸附层。     

云南某萤石与重晶石共生矿选矿工艺

针对萤石重晶石共生矿可浮性相近、浮选分离困难的选矿难题,对云南某萤石重晶石共生矿进行了选矿工艺研究. 结果表明,原矿含重晶石44.38%,萤石20.21%,脉石矿物主要为石英. 经多个实验流程对比后,最终采用萤石和重晶石混合浮选流程,以皂化油酸钠为捕收剂. 采用抑重浮萤的流程,以硫酸铝为重晶石抑制剂,保证萤石可浮性. 经闭路分选流程得到品位96.13%、回收率88.74%的萤石精矿和品位87.65%、回收率97.78%的重晶石精矿.     

F-在方解石表面的吸附及其对方解石表面性质的影响

氟元素主要存在于磷矿和萤石等矿物中,这些矿物中都伴生有方解石脉石矿物,在浮选分离的弱酸条件下,矿物表面的F^-会部分溶出并吸附到矿物表面,从而影响矿物表面性质。本文研究了F^-在方解石表面的吸附及其对方解石表面性质的影响机理。结果表明,在矿浆pH 值为5.5时,F^-以化学吸附的方式吸附在方解石表面,随着吸附时间的增加吸附量逐渐增加,90 min时方解石对F^-的吸附达到平衡。在油酸钠(NaOL)为捕收剂时,F^-的存在会降低方解石表面的疏水性。通过Zeta电位测试、溶液化学计算和X射线光电子能谱仪(XPS)分析表明,F^-会和方解石表面的Ca²⁺反应生成CaF₂沉淀,占据方解石表面的Ca位点,降低NaOL在方解石表面的吸附量。     

萤石与重晶石浮选分离试验研究

贵州某萤石矿中萤石与重晶石含量高,由于矿物可浮性相近,分离难度较大.本文提出合理的工艺流程及参数,通过几种抑制剂的组合和配制,可使可浮性相近的萤石、重晶石实现有效分离,在开路精选四次试验条件下可得到品位91.89%、回收率74.22%的CaF2精矿.     

四川某地萤石重晶石的浮选分离

我国川东南某地中低温热液重晶石——萤石型矿床的矿石中,含萤石49.28％,重晶石42.93％,和少量方解石、玉髓、褐铁矿等。主要化学组成为(％):Ca 27.24,Ba 25.07,F 24.78,SO_3 15.33。 由于后生成的萤石沿着重晶石裂隙贯入,故矿石内常见萤石脉与重晶石脉相互穿插;部分重晶石受萤石浸入的影响产生变晶,使粗粒板状重晶石变成细小不一粒状集合体;有的重晶石已被萤石溶蚀交代,在萤石内留下许多交代的细小残余体,粒度一般2～20微米。矿石硬度低,易泥化,使得萤石、重晶石难于分离。     

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。     

Analysis of Thin Films on Metal Surfaces

External reflection infrared spectroscopy was used in combination with other surface analysis techniques such as ellipsometry, Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS) to determine the structure of organofunctional silanes adsorbed onto 2024 aluminum and titanium-6 Al, 4V mirrors. The results obtained indicated that the adsorption of γ-aminopropyltriethoxysilane (γ-APS) onto aluminum was a strong function of pH and adsorption time. Films formed by adsorption of γ-APS at pH = 8.5 were composed of polysiloxanes containing amine hydrochlorides. The structure of films formed by adsorption of γ-APS at pH-10.4 depended on time. Films obtained after one minute were composed of polysiloxanes that did not interact strongly with the oxide but during 15 minutes adsorption the air-formed oxide was dissolved and copper accumulated near the surface of the mirrors. Films formed by the adsorption of γ-glycidoxypropyltrimethoxysilane (γ-GPS) onto aluminum were composed of polysiloxanes that did not interact strongly with the oxide. The structure of films formed by adsorption of γ-APS onto titanium did not depend on adsorption time. Films formed at pH = 10.4 were composed of low molecular weight oligomers that gradually polymerized to polysiloxanes during atmospheric exposure.     

Analysis of Thin Films on Metal Surfaces

External reflection infrared spectroscopy was used in combination with other surface analysis techniques such as ellipsometry, Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS) to determine the structure of organofunctional silanes adsorbed onto 2024 aluminum and titanium-6 Al, 4V mirrors. The results obtained indicated that the adsorption of γ-aminopropyltriethoxysilane (γ-APS) onto aluminum was a strong function of pH and adsorption time. Films formed by adsorption of γ-APS at pH = 8.5 were composed of polysiloxanes containing amine hydrochlorides. The structure of films formed by adsorption of γ-APS at pH-10.4 depended on time. Films obtained after one minute were composed of polysiloxanes that did not interact strongly with the oxide but during 15 minutes adsorption the air-formed oxide was dissolved and copper accumulated near the surface of the mirrors. Films formed by the adsorption of γ-glycidoxypropyltrimethoxysilane (γ-GPS) onto aluminum were composed of polysiloxanes that did not interact strongly with the oxide. The structure of films formed by adsorption of γ-APS onto titanium did not depend on adsorption time. Films formed at pH = 10.4 were composed of low molecular weight oligomers that gradually polymerized to polysiloxanes during atmospheric exposure.     

膜与蛋白质溶液的相互作用及膜污染机制的能谱研究

引　言蛋白质溶液的浓缩和分离广泛地存在于食品、医药、水处理以及生物技术等领域 ,膜过滤以其无相变、能耗低、设备简单、占地少等优点而成为浓缩与分离蛋白质物系的重要手段之一 .但由于蛋白质对膜的污染比较严重 ,膜过滤的效率和使用范围受到限制 .为了解决这一问题 ,首先需要深入认识蛋白质污染膜的机理 ,对此 ,人们已进行了一些探讨 .Ｔｒａｃｅｙ[1] 认为蛋白质超滤过程初始的通量下降与孔缩小或孔堵塞模型一致 ,而后长时间的通量下降则可用滤饼形成模型来描述 ;Ｍｅｉｒｅｌｅｓ[2 ] 和Ｋｉｍ[3] 提出 ,是膜面高剪切力引起蛋白质变…     

Study on flotation performances and adsorption mechanism of 2-carboxyethylphenylphosphinic acid to cassiterite

A novel collector, 2-carboxyethylphenylphosphinic acid (CEPPA), was first used in the flotation of cassiterite. The flotation performances and the adsorption mechanism of CEPPA on cassiterite were investigated by flotation tests, adsorption experiments, zeta potential measurements, Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The results indicated that CEPPA had strong collecting power for cassiterite and fluorite over a wide pH range but little on quartz. In the separation of the cassiterite–quartz mixture, a concentrate containing 90.9% SnO₂ was obtained with a recovery of 95.7% at pH 7.0. The cassiterite in the cassiterite–fluorite mixture could be effectively separated using 300 mg/L sodium silicate in conjunction with 60 mg/L CEPPA, and a concentrate with a grade of 90.3% SnO₂ and a recovery of 92.6% was achieved at neutral pH. Zeta potential analysis demonstrated that the adsorption process involved both physical and specific forces. The results of FTIR and XPS further suggested that the four O atoms of CEPPA reacted with the Sn atoms on cassiterite surface, forming a complex which was similar to the Sn–CEPPA precipitate, and hydrogen bonding adsorption could have taken place between the terminal hydroxyl groups and CEPPA anions.