Preparation of Rutile Titanium Dioxide White Pigment by a Novel NaOH Molten‐Salt Process: Influence of Doping and Calcination

Rutile titanium dioxide (TiO₂) white pigment is prepared by a novel NaOH molten‐salt process. Titanium slag is decomposited by NaOH molten salt to obtain sodium titanate which is then converted into hydrate titanium dioxide (H₂TiO₃) through acid dissolution and hydrolysis. Finally, TiO₂ white pigment is prepared by H₂TiO₃ doping and calcinations. H₂TiO₃ prepared by this innovative method is characterized and the influencing factors of doping and calcination of H₂TiO₃ on pigmentary properties of TiO₂ are investigated. H₂TiO₃ with certain characteristics could be prepared through the controlled hydrolysis step in the NaOH molten‐salt process. Good pigmentary properties of rutile TiO₂ white pigment are achieved by doping with suitable amounts of K₂O, P₂O₅, Al₂O₃, and rutile nuclei, thereby approaching the quality of the commercial TiO₂ pigment standards.     

The role of V in rutile-type Sn/V/Nb/Sb mixed oxides, catalysts for propane ammoxidation to acrylonitrile

Rutile-type Sn/V/Nb/Sb mixed oxides of composition Sn/V/Nb/Sb 1/x/1/3 (atomic ratios) were prepared by co-precipitation from an alcoholic medium, characterized and tested as catalysts for the ammoxidation of propane to acrylonitrile. Vanadium had a relevant effect on chemical–physical and reactivity properties of catalysts. The latter consisted of Sn oxide incorporating Sb and Nb cations, of defective rutile-type V/Nb/Sb mixed oxide and of Sb oxide. Increasing amounts of V in samples caused an increase of the crystallinity and a corresponding decrease of the specific surface area. However, a relevant enhancement of the catalyst activity (rate of propane conversion per unit surface area) was observed. This was attributed to the generation of cationic vacancies, formed in the rutile-type V/Nb/Sb mixed oxide, that enhanced the intrinsic activity of V ions in the activation of the alkane. On the other hand, the selectivity to acrylonitrile declined considerably when the content of V in samples was increased, whereas the selectivity to carbon monoxide and that to cyanhydric acid increased.     

乳化煤油在金红石与石榴石浮选分离中的增效作用研究

针对金红石与石榴石浮选分离过程中羟肟酸类捕收剂选择性好,但捕收能力较弱的问题,以乳化煤油为增效剂,金红石与石榴石单矿物和人工混合矿为浮选对象,对改善水杨羟肟酸(SHA)的捕收能力进行了试验。单矿物浮选试验表明:经Tween80乳化的煤油改善SHA浮选性能的效果最好;相比乳化煤油与SHA混合一步添加,分步添加的浮选效果更佳;增大乳化剂用量能提升金红石的上浮率,乳化剂Tween80与煤油较好的质量比为3.0%。提高矿浆中乳化煤油的浓度,能大幅度提高金红石上浮率,但会影响SHA对金红石和石榴石浮选的选择性。人工混合矿浮选试验表明:以铅离子为活化剂、乳化煤油为捕收增效剂、MIBC为起泡剂,浮选矿浆p H=6.3附近时,较低用量的SHA就能实现金红石与石榴石的高效分离。     

河南付金川金红石矿床地质特征及远景评价

为开发利用付金川金红石矿,综合分析了矿区以往地质资料,并在实地勘探、样品测试和重点地段综合研究的基础上,从区域成矿地质背景、矿区地质特征、矿床地质特征、金红石赋存状态、矿床成因等方面对付金川金红石矿床进行了综合研究,总结了找矿标志,并从成矿潜力、矿石加工技术、矿床开采技术条件、矿产经济效益等方面评价了矿床综合利用远景。研究表明：①付金川金红石矿为位于留山-羊册金红石矿带上的具有大型规模的层状变质火山岩型矿床,赋存于中元古界左老庄岩组地层中,矿体受地层控制,展布稳定;②含矿岩石主要为斜长角闪片岩和黑（二）云斜长片岩,矿石多为粗粒级易选型金红石;③矿床成矿潜力大,矿石加工性能良好,矿床开采技术条件简单,矿产经济效益较好,具有较好的开发利用远景。     

某金红石矿选矿试验研究

针对某金红石矿结构复杂、嵌布粒度微细的特点,在探索试验的基础上,采用"浮选—高梯度磁选—加温电选"的联合工艺流程,获得精矿Ti O2品位为71.2%,回收率为49.56%的指标。     

烷胺双甲基膦酸浮选金红石的研究

在适宜的pH条件下,十二胺双甲基膦酸对金红石的捕收性能优于苄基胂酸,且该药无毒性、用量少、价格低,可自行合成。添加适量的氟硅酸钠抑制剂。能有效地实现金红石与柘榴石、角闪石的分离。十二胺双甲基膦酸在金红石表面以化学吸附为主。     

Structure of nanotubular titanium oxide templates prepared by electrochemical anodization in H2SO4/HF solutions

The electrochemical formation of nanotubular titanium oxide films was investigated in 1 M H₂SO₄ and 0.05-0.4 wt.% HF electrolytes. Depending on anodization condition, i.e. cell voltage, anodization time, HF concentration, TiO₂ porous films having different thickness (from 350 to 500 nm) and pore diameter (from 40 to 150 nm) were obtained. By varying the cell voltage from 10 V to 40 V it was possible to gradually change the crystal structure of titanium oxide from anatase to rutile. The effect of annealing temperature and duration on crystal structure was also considered.     

Microstructural Characterization and Tensile Behavior of Rutile(TiO_2)-Reinforced AA6063 Aluminum Matrix Composites Prepared by Friction Stir Processing

Rutile(TiO_2) particle-reinforced aluminum matrix composites were prepared by friction stir processing. The microstructure was studied using conventional and advanced characterization techniques. TiO_2 particles were found to be dispersed uniformly in the composite. Clusters of TiO_2 particles were observed at a higher particle content of 18 vol%. The interface between the TiO_2 particle and the aluminum matrix was characterized by the absence of pores and reactive layer.Sub-grain boundaries, ultra-fine grains and dislocation density were observed in the composites. TiO_2 particles improved the mechanical properties of the composites. However, a drop in tensile strength was observed at a higher particle content due to cluster formation. All the prepared composites exhibited ductile mode of fracture.     

由改性高钛渣浸出制备富钛料的研究

还原法制备的高钛渣 ,品位低 ,不适合直接作硫酸法和氯化法制备钛白的原料 ,经预氧化及加入添加剂等改性处理后可使钛组分富集于金红石相。选用经选择性富集的改性渣为原料 ,研究了改性渣中钛组分的选择性分离及其反应机理。实验结果表明 ,通过稀酸溶出改性渣可获得Ti O2 品位超过 95 %的人造金红石     

Photocatalytic production of oxygen in a dual bed system using a reversible redox mediator on Ir-TiO<Subscript>2</Subscript> catalyst

Photocatalytic O₂ evolution by water splitting in an alkaline solution with a redox mediator was investigated in a dual bed system configuration: one bed was used for oxygen evolution and the other for hydrogen evolution. The employed photocatalyst was Ir-TiO₂ and the iodate ion, KIO₃, was used as a redox mediator. In order to find the optimum conditions for oxygen evolution, the effect of alkaline concentration, KIO₃ concentration and the amount of Ir loading on the photocatalytic reactivity was examined in an irradiation area of 0.055 m² reactor with a 400 W U.V. lamp. The experimentally obtained results showed that oxygen evolution depends on the concentration of the alkaline solution, the potassium iodate concentration and the amount of Ir loading.