摘要钛作为 21 世纪的重要战略材料，在航空、电力、医疗等领域均有广泛的应用， 目前生产钛的主要方法还是镁还原法，而人们也探索用溶剂萃取法来制取人造金红 石。采用浊点萃取法对钛进行萃取分离与富集，方法操作简便、不使用挥发性有机溶 剂、相分离界面清晰，以低品位钛铁矿、含钛高炉渣、含钛废水为原料，对其中的钛 进行萃取分离富集，进行工业生产人造金红石有很好的应用前景。83546

本论文利用非离子表面活性剂 Triton X-100 对酸性体系溶液中 Ti4+进行浊点萃 取，利用分光光度法检测金属离子的浓度。采用单因素实验，探讨了 KSCN 浓度、 溶液酸度、静置时间等因素对萃取率 E 的影响。

结果表明，萃取前向体系中分别加入无机盐 NaCl 和 Na2SO4，适当降低浊点温度， Na2SO4 因离子强度更大，效果更显著。在 Na2SO4 降低浊点温度的体系中，以萃取过 程采用体系总量 2。5 wt%的 Triton X-100 为萃取剂，0。060 mol/L 的 KSCN 为络合剂， 酸度 pH 值为 2，萃取平衡 50 min，萃取液 3000 rpm 离心 8 min，Ti4+的萃取率为 98%， 并且在金属离子共存体系中 Ti4+与 Mn(II)、Al(III)、Fe(II)等离子分离情况较好。

对非离子表面活性剂浊点萃取 Ti4+过程的热力学、动力学进行了研究。得出结果 如下：

（1）热力学内容：萃取过程中热力学的萃取平衡方程为：



萃取反应过程中焓变 r H  =13。37 kJ/mol，该反应为吸热反应。

（2）动力学内容：以非离子表面活性剂 Triton X-100 浊点萃取 Ti4+的萃取反应为一级 反应； 正向萃取表观活化能 Ea 为 17。596 kJ/mol，萃取过程动力学控制类型为扩散控 制类型；萃取 Ti4+的速率方程为：

dC  4 - Ti         100。4534 [Ti 4][H ]0。065 [Triton ]0。158

dt关键字：钛（Ⅳ）；非离子表面活性剂；浊点萃取；分离富集；萃取热力学、动力学；

Abstract

Titanium as an important strategic material for the 21st century, has been widely used in aviation, electric power, medical and other fields。 At present, the main method of producing titanium is magnesium reduction method and sodium reduction method, and people also explore the use of solvent extraction method to prepare rutile。 Cloud point extraction (CPE) is a king of newly-rising separation technique of liquid-liquid extraction。 Compared with the traditional separation technologies, CPE is an environment friendly technology because of nonusing volatile organic solvents and maintaining advantages in simplicity of operator, low cost, high speed and sensitivity。 The method has been widely applied in the fields of environmental science, life science and so on。 In recent years, the cloud point extraction separation and enrichment of nonionic surfactant was also successfully applied to metal ions。

The main content of this paper is the cloud point extraction of Ti4+ in acid solution using nonionic surfactant Triton X-100 and the concentration of metal ions was detected by spectrophotometry。 To explore the influence of different experimental conditions on the extraction rate for cloud point extraction, the KSCN  concentration,  solution acidity, non ion surfactant concentration, standing time, additives and other experimental conditions were investigated。

The results show that when the concentration of Triton X-100 is 2。5wt%, the concentration of KSCN is 6。0×10-2 mol/L, selecting acidity (pH=2), the equilibrium time is 45 min, centrifugal time for 8 minutes, adding inorganic salt as appropriate to reduce the cloud point temperature, the result of separation and enrichment is of great satisfaction。

The thermodynamics, kinetics and reaction mechanism of the process of nonionic surfactant cloud point extraction of Ti4+ were studied。 The results obtained are as follows: