Synthesis and color tuning of titanium oxide inorganic pigment by phase control and mixed-anion co-doping

B and N co-doped anatase, rutile, and brookite TiO₂ (abbreviated as BN-Ana, BN-Rut, and BN-Bro) were successfully synthesized. The apparent color of as-obtain BN-Ana, BN-Rut and BN-Bro was red, cyan and yellow-green, respectively. The mechanisms of various coloring were concluded as the different band gap configurations and the formation of covalent B-N bonding. The nitridation time expressed less effect on changing the color. On the contrary, nitridation temperature enabled the distinct color changes by altering the brightness. Lower temperature, fewer doping concentration, and brighter apparent color, vice versa. Through tuning the brightness, a gradient of yellow-orange-red was achieved in the case of BN-Ana, as well the transitions of grey-to-cyan and white-to-pale-yellow were achieved in BN-Rut and BN-Bro, respectively. This research proposed a method for the synthesis of color-full titania pigment without the addition of other toxic transition metal elements.     

盐酸常压直接浸出攀西地区钛铁矿制备人造金红石

以攀西地区钛铁矿为原料，采用．盐酸常压直接浸出法制备高品位人造金红石。结果表明，原矿粒度及盐酸浓度对人造金红石品位影响最大。采用液固比4：1、盐酸浓度30％、温度95℃的条件，对于球磨4h钛精矿浸出4h可得到TiO2含量94．39％的人造金红石产品，对于未磨原矿浸出10h可得TiO2含量91．78％的人造金红石产品。     

风化细粒钛铁矿及伴生金红石的选矿试验研究

就云南某地风化严重的细粒钛铁矿及伴生金红石进行了选矿试验研究,在采用弱磁选—强磁选工艺不能获得理想的指标后,采用弱磁选—强磁选—还原焙烧—弱磁选—浮选—重选—酸浸的工艺流程,获得了理想产品,铁精矿品位61.08%,回收率6.23%;钛铁精矿TiO2品位49.69%,回收率87.33%;金红石精矿TiO2品位86.57%,回收率11.77%。     

选择氯化钛铁矿制取人造金红石

研究了选择氯化钛铁矿制取人造金红石反应的Ｆｅ－Ｔｉ－Ｃ－Ｏ２－Ｃｌ２系平衡图,计算了氧与某些氯化物相互作用的自由能变化,采用“通氧一步选择氯化法”,在钛铁矿原料中配加适量的碳,并往炉内通入相应量的氧气或空气,可以解决选择氯化“自热”反应持续进行的技术关键．对反应参数,如温度、配碳量、物料粒度、氯化时间和通氧量等均进行了实验室、半工业和工业化生产试验研究．研究证明,选择氯化过程的动力学模型是“固体颗粒粒度保持不变的缩核反应模型”,动力学区的活化能为３４．３３ｋＪ／ｍｏｌ;扩散区的活化能为０．８０ｋＪ／ｍｏｌ．试验结果表明,这种选择氯化新工艺具有流程短、产能大、产品质量好、成本低、操作简单等优点．研究开发的无筛板沸腾氯化炉可以长期稳定地连续运转,生产出的人造金红石品位为９２．１０％．经摇床和磁选,品位达到９５％,钛的回收率和氯的利用率都大于９５％,床层单位炉产能达１２．４ｔ／ｍ２ｄ．该工艺和设备已成功地应用于工业生产．     

Kinetic study of photocatalytic degradation of carbamazepine, clofibric acid, iomeprol and iopromide assisted by different TiO2 materials--determination of intermediates and reaction pathways

The light-induced degradation of clofibric acid, carbamazepine, iomeprol and iopromide under simulated solar irradiation has been investigated in aqueous solutions suspended with different TiO2 materials (P25 and Hombikat UV100). Kinetic studies showed that P25 had a better photocatalytic activity for clofibric acid and carbamazepine than Hombikat UV100. For photocatalytic degradation of iomeprol Hombikat UV100 was more suitable than P25. The results can be explained by the higher adsorption capacity of Hombikat UV100 for iomeprol. The study also focuses on the identification and quantification of possible degradation products. The degradation process was monitored by determination of sum parameters and inorganic ions. In case of clofibric acid various aromatic and aliphatic degradation products have been identified and quantified. A possible multi-step degradation scheme for clofibric acid is proposed. This study proves the high potential of the photocatalytic oxidation process to transform and mineralize environmentally relevant pharmaceuticals and contrast media in water.     

高钛渣氧化焙烧行为研究

针对钛工业对人造金红石品质的要求,进行高钛渣常规氧化焙烧试验,考察不同焙烧温度下高钛渣样品重量变化、二氧化钛品位、脱硫和脱碳效果。结果表明,高钛渣在常规焙烧条件下主要发生低价金属氧化物的氧化反应,随着焙烧温度的提高,氧化反应越容易进行,因此样品重量增重越明显,同时二氧化钛品位由于样品总重量的增加而明显下降,而杂质中的硫和碳在高温下与氧结合生成SO2、CO和CO2逸出。     

青海丁叉叉山地区金红石矿床地质特征及找矿前景

丁叉叉山地区金红石矿床位于柴北缘成矿带东端,为近年新发现的大型金红石矿床。矿床产于古元古界金水口群地层榴辉岩体中,严格受榴辉岩体的控制。呈条带状、透镜状产出,近东西向展布。成因类型属榴辉岩型金红石矿床,成矿时期为加里东期。在总结区内矿床地质特征的基础上,进而与国内苏鲁榴辉岩金红石矿床、省内鱼卡榴辉岩型金红石矿床等典型矿床对比分析,研究表明:区内榴辉岩成矿条件有利,保存条件良好,具有较好的找矿前景。     

Mechanical and Tribological Properties of Ca/P-Doped Titanium Dioxide Layer Produced by Plasma Electrolytic Oxidation: Effects of Applied Voltage and Heat Treatment

Plasma electrolytic oxidation (PEO) is a technique that produces a hard oxide layer on the titanium surface where its properties can be tailored by changing the process parameters or by a posterior heat treatment (HT). In this work, a TiO₂ layer with different crystallinity was produced by PEO with different applied voltages (250 to 400 V) and post-HT at 600°C. Our aim was to evaluate the influence of the PEO voltage and HT on the mechanical and tribological properties of anodized Ti. There is an increase in pore size, oxide thickness, and Ca/P ratio for the oxide layer with the applied voltage during the PEO process. X-ray diffraction (XRD) results indicated an increase in the crystalline rutile phase in the oxide layer with voltage and HT. Nanoindentation shows an increase in the oxide hardness and elastic modulus with increased voltage and HT, leading to an improvement in the wear resistance.     

Ce掺杂改性TiO_2对MNO_x/Ce-TiO_2体系催化活性的影响

以Ce掺杂的TiO2粉体为载体,MNOx为活性组分,制备了MNOx/Ce-TiO2体系SCR催化剂,利用TG-DSC,XRD,SEM及EDS考察了Ce的掺杂对MNOx/TiO2体系活性的影响,采用模拟烟气分析装置测试催化剂的活性。结果表明：Ce离子的掺杂阻碍了TiO2粒子由锐钛矿型向金红石型的转变,拓宽了锐钛矿型TiO2的使用温度范围。TiO2粉体粒子在锐钛矿型状态下,颗粒分散较为均匀,并且无明显团聚现象,保证了较高的比表面积,催化剂的SCR催化活性比未掺杂的催化剂活性有明显的提高。     

氮掺杂对金红石二氧化钛光电特性影响的理论研究

运用第一性原理LDA+U方法,计算不同浓度氮元素掺杂金红石相二氧化钛的能带结构、态密度和光学性质,研究显示氮元素的掺入使TiO_2-x N _x 体系带隙变窄。而O-2p与N-2p轨道杂化耦合在费米能级附近出现了杂质能级,促使载流子跃迁变容易,从而拓展了TiO_2-x N _x 体系对可见光的响应范围。此外,杂质能级对电子-空穴对的复合有抑制作用,对光催化活性的提升具有积极作用。研究结果表明,当氮元素掺杂量（x）为0.062 5时,TiO_2-x N _x 体系光吸收性能与光电响应较好。