低浓度稀土溶液大相比萃取富集的应用基础研究

萃取技术在冶金行业应用广泛，但是，传统萃取设备不适用于从稀溶液中分离和富集目标组分。本论文采用大相比萃取法从稀溶液中分离和富集目标组分。大相比是将萃取剂以&ldquo;油泡&rdquo;的形式分散后实现的。&ldquo;油泡&rdquo;是一种核-壳结构，气体构成&ldquo;油泡&rdquo;的核，萃取剂构成&ldquo;油泡&rdquo;的壳。在核壳结构中作为壳的萃取剂，体积小，但是与萃取液的接触面积大。&ldquo;油泡&rdquo;在萃取液中上升时，目标组分从萃取液中传质到&ldquo;油泡&rdquo;表面实现萃取。本论文以稀土离子-萃取剂作为模型体系，采用大相比萃取方法萃取稀土离子，主要的研究内容包括：以稀土离子La3+、Er3+作为代表性目标组分，以本论文发明的分布器为模型设备，对大相比萃取稀土离子进行了研究。对通气速率、通油速率以及气油比影响Er3+的萃取进行了研究。发现了通气速率、通油速率影响&ldquo;油泡&rdquo;萃取的规律；计算了&ldquo;油泡&rdquo;萃取时的体积传质系数。在萃取是一种界面行为的理论指导下，探讨了大相比萃取用于分离富集目标组分的机制。研究结果表明，稀土离子可以通过大相比萃取的方式从稀溶液中实现富集和分离。在本论文发明的恒界面池内对&ldquo;油泡&rdquo;萃取的本征动力学进行了研究。采用CFD模拟了在恒界面池内萃取液与萃取剂的流动状况。在实验中系统地研究了流动速度、界面面积、酸碱度以及萃取剂浓度对Er3+萃取速率的影响。CFD的结果表明，萃取剂和萃取液在本论文发明的恒界面池内的流动符合恒界面池测定动力学的要求。实验结果表明，Er3+被P507-煤油萃取时符合拟一级动力学方程，并给出了萃取速率方程。研究了模型设备内&ldquo;油泡&rdquo;稳定生成的条件。实验结果表明，内外管顶端的高度差、环隙宽度和操作条件共同影响&ldquo;油泡&rdquo;的稳定生成。环隙宽度小（0.17~0.22 mm），套嵌圆管内外管的高度差（-2~48 mm）对形成&ldquo;油泡&rdquo;无明显影响。套嵌圆管内外管的高度差-2~6 mm时，环隙宽度在（0.17~0.365 mm）的范围内，对形成&ldquo;油泡&rdquo;无明显影响。总结了套嵌圆管的结构参数和操作条件对&ldquo;油泡&rdquo;稳定生成的规律。对目标组分从稀溶液中的萃取强化进行了研究。研究结果表明，单位横截面积的萃取柱内，套嵌圆管数目、气体流速、萃取剂流速对&ldquo;油泡&rdquo;萃取速率有不同程度的影响。在分布器能够将萃取剂分散成&ldquo;油泡&rdquo;的所有萃取剂流速范围内，萃取速率随通气速率的增加而增加。通气速率相同时，通油速率的增加不能显著的影响萃取速率。论文提出了大相比萃取设备的强化规律：气体在萃取柱横截面内的流动速率为0.08 cm/s，通气速率与通油速率的比值约为300:1，单个套嵌圆管所占的萃取柱横截面积为12.7 cm2。;Liquid&ndash;liquid extraction is the core technology and widely used in the hydrometallurgical industry. However, traditional extractors can not be used to extract target component from diluent solution. Extraction featured large phase ratio is suggested and used to separate and enrich target component from diluent solution in the dissertation. The large phase ratio is realized by dispersing the extractant into organic bubble. The organic bubble is a core-shell structure, in which the core is composed of gas phase and the shell is a thin layer of extractant. The volume of the extractant is small but the interface between extractant and diluent solution is as large as the surface area of organic bubble.Target component transfers to the extractant from diluent solution during floatation of extractang bubble. In the model system of rare eath ions and extractant, rare earth ions are extracted by solvent extraction featured large phase ratio. The research contents include mainly:La3+, Er3+ as the representative rare earth ions are extracted with large phase ratio in the model device, which is invented in the dissertation. And the research contents include the effects on the extraction rate of flow rates of extractant and gas phase. The volume mass transfer coefficient is calculated. The mechanism of extraction featured large phase ratio for separation and enrichment of target components is discussed. The results indicate that target components can be enriched by extraction featured large phase ratio.The extraction intrinsic kinetics of organic bubble is studied in constant interfacial area cell, which is designed in the dissertation. The flow states and velocity profiles in the cell are simulated by CFD method. The flow rates of two phases, the interfacial area, acidity and the concentraion of extractant are studied systematically through the extraction experiment in which Er3+ is extracted by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester.The results of CFD indicate that the flow situation meets the requirements in the constant interfacial cell. And the results of the experiment indicate that the extraction rate for Er3+ match pseudo first order kinetics. And the extraction rate equation of Er3+ extracted by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester is deduced.The key factors for the formation of organic bubble are studied under the large phase ratio. The results indicate that the difference between the height of inner tube and outer tube, the width of gap between two tubes and operating conditions play important role during the formation of extractant bubble. The height of inner tube and outer tube, the width of the gap between the inner tube and the outer tube and operation conditions determine whether the extractant can be dispersed into organic bubble jointly. The difference between the height of inner tube and outer tube from -2 mm to 48 mm has no effect on the formation of organic bubble when the gap is from 0.17 to 0.22 mm. The width of the gap between inner tube and outer tube from 0.17 mm to 0.365 mm has no effect on the formation of organic bubble when the difference between the height of inner tube and outer tube is from -2 mm to 6 mm. Effects on organic bubble formation of structural factors and operating conditions are summerized.The intensification about extraction featured large phase ratio is studied in the model device. The result indicates that the number of pairs of nested tubes, flow rates of gas phase and extractant per unit cross sectional area affect extraction rate with different degree in the model device. In the flow rate range of extractant under the condition of organic bubble formation, the extraction rate increases with the increase of flow rate of gas phase. With the same flow rate of gas phase, the increase of flow rate of extractant can not significantly affect the extraction rate. The intensification criteria are summarized that the velocity of gas phase in the whole cross sectional area is 0.08 cm/s, the flow ratio between gas phase and extractant is about 300:1, and the cross section area of extraction column with one pair of nested tubes is 12.7 cm2.&nbsp;</p

Study on Urea Coated with Lignocellulose

农业上化肥的过度施用和低的利用率造成了成本增加和对环境的破坏。本研究以来源广泛、成本低廉的木质纤维素作为包膜材料对尿素包膜，研制出既有缓释功能又具有土壤改良作用的包膜尿素，并检验该产品的缓释性能，研究缓释过程和机理，用作物盆栽试验检验肥料的使用效果，目的是开发一种新型缓释肥料，提高肥料利用率，并为木质纤维素的利用提供一个新途径。本论文包括以下几部分内容： 制备包膜尿素。废弃杂木经粉碎至60目作为包膜材料对尿素进行包膜。通过对包膜材料、辅助制剂及制备工艺的研究，开发出木质纤维素包膜尿素的实验室制备工艺：以聚丙烯酰胺为粘合剂，用团粒法进行包膜，以固体石蜡为封闭剂。研究提出了最佳的原料配比（造粒机转速30r/min、粘结剂0.1wt%聚丙烯酰胺20ml、包膜材料40g）和操作程序，制定出包膜尿素的工艺流程。 研究包膜尿素的缓释性能。用水/溶液中溶出率试验、土壤淋溶试验、土肥混合培养试验对其缓释性能作了全面的研究，结果表明：包膜材料含量为8％和10％时在水/溶液中的初期溶出率和微分溶出率在一个合理的范围内，说明该肥料有较好的缓释性能；在10℃－30℃范围内，温度对养分的溶出率影响不大；在离子浓度高的溶液中尿素溶出率下降；土壤淋溶试验结果表明包膜尿素有较好的缓释性能；土肥混合培养试验结果表明包膜尿素的养分释放与土壤水分含量有关，水分含量越高，释放越快。 研究包膜尿素的应用效果。以盆栽试验在小麦和棉花上进行了包膜尿素应用效果研究。结果表明，与普通尿素相比，施用包膜尿素，小麦在苗期对氮素的利用率提高了10.98％，在等用量的情况下，施用包膜尿素比普通尿素，小麦生物量提高了10.28％。棉花盆栽实验结果表明，施用含有尿酶抑制剂的木粉包膜尿素，不仅可以延缓尿素的溶解速度，还可以有效抑制土壤脲酶活性和硝化与反硝化作用，试验还表明施用包膜尿素对土壤微生物数量没有不良影响。 以上结果表明，木质纤维素包膜尿素是一种有较好应用价值的新型缓释肥料

混合澄清萃取槽内水油两相相比变化对其操作性能的影响

综述了混合澄清槽中水油两相相比(流比)变化对混合室内液滴分散、目标组分传质及澄清室内两相分离影响的相关研究,讨论了相比变化时搅拌桨桨型与安装位置对混合室和澄清室性能的影响,对混合澄清槽今后的发展如何适应更宽的操作相比及强化混合室高效混合、澄清室快速澄清进行了探讨

混合澄清萃取槽内水油两相相比变化对其操作性能的影响

综述了混合澄清槽中水油两相相比(流比)变化对混合室内液滴分散、目标组分传质及澄清室内两相分离影响的相关研究,讨论了相比变化时搅拌桨桨型与安装位置对混合室和澄清室性能的影响,对混合澄清槽今后的发展如何适应更宽的操作相比及强化混合室高效混合、澄清室快速澄清进行了探讨.</p

混合澄清萃取槽内水油两相相比变化对其操作性能的影响

综述了混合澄清槽中水油两相相比(流比)变化对混合室内液滴分散、目标组分传质及澄清室内两相分离影响的相关研究,讨论了相比变化时搅拌桨桨型与安装位置对混合室和澄清室性能的影响,对混合澄清槽今后的发展如何适应更宽的操作相比及强化混合室高效混合、澄清室快速澄清进行了探讨

木质素作为包膜材料包裹尿素的缓释效果研究

用盆栽实验的方法研究施用添加有脲酶抑制剂(nBPT)的木质素包裹尿素(nBPTLCU)对土壤的生化效应。与施用普通尿素相比,加有nBPTLCU的土壤尿素态氮和铵态氮含量较多,说明nBPTLCU可以减缓尿素的释放;在土壤深处的硝态氮含量和脲酶活性较低,说明硝化作用受到抑制;土壤微生物碳氮含量差异不显著,说明施用nBPTLCU对土壤微生物没有不良的影响。结果表明,nBPTLCU是一种具有较好缓释性能的肥料

木质素作为包膜材料包裹尿素的缓释效果研究

用盆栽实验的方法研究施用添加有脲酶抑制剂（nBPT）的木质素包裹尿素（nBPTLCU）对土壤的生化效应。与施用普通尿素相比，加有nBPTLCU的土壤尿素态氮和铵态氮含量较多，说明nBPTLCU可以减缓尿素的释放；在土壤深处的硝态氮含量和脲酶活性较低，说明硝化作用受到抑制；土壤微生物碳氮含量差异不显著，说明施用nBPTLCU对土壤微生物没有不良的影响。结果表明，nBPTLCU是一种具有较好缓释性能的肥料

黑液制备的腐植酸液肥和调理剂的棉花田间应用研究

为了给黑液实现资源化利用提供依据。在新疆进行了黑液腐植酸产品的田间试验,设计了3个处理,采用棉花定点定株方法调查其生理指标,并测定其生化指标,研究了它们对棉花的生长、产量和抗旱能力的影响。结果表明,在滴灌中应用腐植酸液肥,与常规固体肥料相比可明显促进棉花在各生育期的生长、能增加蕾、花和铃的数量、并且延长成熟时间、作物不易早衰。同时,液肥还可提高棉花的经济性状,能够显著增加籽棉的产量,增产率可达12.3%。在棉花上使用该腐植酸产品后可降低叶片的蒸腾速率,提高叶片的保水能力和CAT活力,从而明显增强棉株的抗旱能力。黑液腐植酸产品对棉花具有良好的促长、增产和抗旱效果

黑液制备的腐植酸液肥和调理剂的棉花田间应用研究

为了给黑液实现资源化利用提供依据。在新疆进行了黑液腐植酸产品的田间试验,设计了3个处理,采用棉花定点定株方法调查其生理指标,并测定其生化指标,研究了它们对棉花的生长、产量和抗旱能力的影响。结果表明,在滴灌中应用腐植酸液肥,与常规固体肥料相比可明显促进棉花在各生育期的生长、能增加蕾、花和铃的数量、并且延长成熟时间、作物不易早衰。同时,液肥还可提高棉花的经济性状,能够显著增加籽棉的产量,增产率可达12.3%。在棉花上使用该腐植酸产品后可降低叶片的蒸腾速率,提高叶片的保水能力和CAT活力,从而明显增强棉株的抗旱能力。黑液腐植酸产品对棉花具有良好的促长、增产和抗旱效果

抗寒生化制剂对棉花幼苗生理生化特性的影响

目的探讨抗寒制剂拌种处理对棉花的作用效果及机理,为其推广应用提供依据。方法用盆栽的方法研究在低温胁迫下经抗寒制剂拌种处理过的棉种发芽及生长情况,并考察棉苗的叶片相对含水量、蒸腾速率、叶绿素和脯氨酸含量等生理生化指标的变化情况。结果在常温和低温胁迫两种条件下,抗寒剂均可以提高棉种出苗率和增强幼苗长势,并均可增加棉株幼苗叶片的相对含水量、蒸腾速率和叶绿素含量,同时可促进渗透调节物质脯氨酸的积累,降低丙二醛的毒害,并增强过氧化氢酶的活性。其中在低温胁迫条件下,抗寒剂的促进效果更为明显。结论抗寒制剂能很好地促进棉种及棉苗的新陈代谢,增强其在低温下的抗逆性