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Enhancing flotation recovery of phosphate ores using nonionic surfactants.

机译：使用非离子表面活性剂提高磷酸盐矿石的浮选回收率。

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摘要

The beneficial effect of nonylphenol polyethylene glycol ether and various PEO/PPOPEO type triblock copolymer surfactants were investigated to enhance the flotation of Central Florida phosphate ores. Pure sodium oleate and dodecane were used as model reagents for fatty acids and fuel oil, respectively. In order to elucidate ore flotation results equilibrium and dynamic surface tension, emulsification, adsorption, contact angle, and microflotation experiments were carried out.; Equilibrium and dynamic surface tensions of single and binary surfactant solutions of sodium oleate and nonionic surfactant were carried out to determine synergistic effect of surfactant mixtures. Interaction parameter between sodium oleate and nonionic surfactant was calculated from equilibrium surface tension data by using suitable thermodynamic model. The dynamic surface tension results were analyzed by using a model in which surfactant adsorption is considered to follow the Langmuir isotherm. Kinetics of emulsification of dodecane with nonionic surfactants was studied by droplet size distribution of dodecane as a function of time. The results showed that droplet size of dodecane became finer in the presence of nonionic surfactants. A phenomenological model was used to analyze the kinetics of emulsification of dodecane.; The presence of nonionic surfactants decreased the adsorption of sodium oleate on pure apatite mineral possibly due to competition for surface sites. The nonionic surfactants increased the contact angle of oleate on apatite at low surfactant concentrations but decreased at high concentrations. Effect of presence of Ca2+ ions on adsorption and contact angle of surfactants on apatite was investigated. It was found that the detrimental effect of dissolved Ca2+ ions on sodium oleate could be reduced in the presence of nonionic surfactants. It is considered that nonionic surfactants forms mixed micelles with sodium oleate and hence protects the collector from hard ions (e.g. Ca2+) to be consumed as an insoluble calcium oleate.; Microflotation of pure apatite and calcite minerals showed that the recovery of pure minerals depends on the PEO groups in the nonylphenol and PEO/PPO/PEO type surfactants. It was seen that flotation recovery decreased with higher ethoxylation in the structure. Presence of Ca2+ ions was found very detrimental to the flotation of pure minerals by sodium oleate alone. But, presence of nonionic surfactants enhanced the flotation of minerals significantly and the detrimental effect of Ca2+ ions was compensated.; The performance of surfactants was tested in batch flotation of three different size fractions of phosphate ores, namely coarse (−16+35 mesh), fine (−35+150 mesh), and very fine (−150+400 mesh) sizes. Flotation of phosphate ores was conducted in distilled and tap water. Presence of nonionic surfactant increased the recovery of fine and very fine size phosphate ores. The beneficial effect of nonionic surfactant was more significant when tap water was used in the experiments. In the flotation of coarse size phosphate ore the nonionic surfactant was beneficial only at high dosages of sodium oleate and dodecane.
机译：研究了壬基酚聚乙二醇醚和各种PEO / PPOPEO型三嵌段共聚物表面活性剂对增强佛罗里达州中部磷酸盐矿石浮选的有益作用。纯油酸钠和十二烷分别用作脂肪酸和燃料油的模型试剂。为了阐明矿石浮选结果，进行了平衡和动态表面张力，乳化，吸附，接触角和微浮选实验。对油酸钠和非离子表面活性剂的单一和二元表面活性剂溶液进行平衡和动态表面张力测定，以确定表面活性剂混合物的协同作用。通过使用合适的热力学模型，由平衡表面张力数据计算出油酸钠与非离子表面活性剂之间的相互作用参数。通过使用其中表面活性剂吸附遵循Langmuir等温线吸附的模型来分析动态表面张力结果。通过十二烷的液滴尺寸分布随时间的变化，研究了十二烷与非离子表面活性剂乳化的动力学。结果表明，在非离子表面活性剂存在下，十二烷的液滴尺寸变得更细。用现象学模型分析十二烷的乳化动力学。非离子表面活性剂的存在降低了油酸钠在纯磷灰石矿物上的吸附，这可能是由于竞争表面部位所致。在低表面活性剂浓度下，非离子表面活性剂增加了油酸盐在磷灰石上的接触角，但在高浓度下降低。研究了Ca 2 + 离子的存在对磷灰石表面活性剂吸附和接触角的影响。研究发现，在非离子表面活性剂的存在下，溶解的Ca 2 + 离子对油酸钠的有害作用可以降低。认为非离子表面活性剂与油酸钠形成混合胶束，因此保护了捕集剂免受硬离子（例如Ca 2 + ）的吸收，以难溶的油酸钙的形式被消耗。磷灰石和方解石矿物的微浮选表明，纯矿物的回收取决于壬基酚和PEO / PPO / PEO型表面活性剂中的PEO基团。可以看出，随着结构中乙氧基化程度的提高，浮选回收率降低。发现Ca 2 + 离子的存在对仅油酸钠的浮选纯矿物非常有害。但是，非离子表面活性剂的存在显着增强了矿物的浮选，并补偿了Ca 2 + 离子的有害作用。表面活性剂的性能在三种不同大小的磷酸盐矿石的分批浮选中进行了测试，分别是粗粒度（−16 + 35目），细粒度（-35 + 150目）和极细粒度（-150 + 400目）。磷酸盐矿石的浮选在蒸馏水和自来水中进行。非离子表面活性剂的存在增加了细粉和极细尺寸磷酸盐矿石的回收率。在实验中使用自来水时，非离子表面活性剂的有益效果更为显着。在浮选粗磷酸盐矿石中，非离子表面活性剂仅在高剂量油酸钠和十二烷时才有用。

著录项

  • 作者

    Sis, Hikmet.;

  • 作者单位

    The Pennsylvania State University.;

  • 授予单位 The Pennsylvania State University.;
  • 学科 Engineering Metallurgy.
  • 学位 Ph.D.
  • 年度 2001
  • 页码 316 p.
  • 总页数 316
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 冶金工业;
  • 关键词

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