硫酸法制取金红石型钛白粉的新工艺研究

通过系统试验,用筛选出的最佳晶型转化剂直接加入到硫酸氧钛水解的产物中,在最佳工艺条件下,经过煅烧和处理后,可生产出金红石型钛白粉。该工艺可为传统硫酸法制取钛白粉技术改革提供重要依据。     

Rheological and volumetric properties of TiO2-ethylene glycol nanofluids

Homogeneous stable suspensions obtained by dispersing dry TiO₂ nanoparticles in pure ethylene glycol were prepared and studied. Two types of nanocrystalline structure were analyzed, namely anatase and rutile phases, which have been characterized by scanning electron microscopy. The rheological behavior was determined for both nanofluids at nanoparticle mass concentrations up to 25%, including flow curves and frequency-dependent storage and loss moduli, using a cone-plate rotational rheometer. The effect of temperature over these flow curve tests at the highest concentration was also analyzed from 283.15 to 323.15 K. Furthermore, the influence of temperature, pressure, nanocrystalline structure, and concentration on the volumetric properties, including densities and isobaric thermal expansivities, were also analyzed.     

Synthesis of highly hydrophobic rutile titania-silica nanocomposites by an improved hydrolysis co-precipitation method

Highly hydrophobic rutile titania-silica nanocomposites were synthesized by an improved hydrolysis co-precipitation method using low-cost sodium metasilicate and titanium oxysulfate (TiOSO₄) as precursors, followed sequentially by calcination at 800 °C and modification with trimethylchlorosilane (TMCS). It was found that the resulting TiO₂-SiO₂ nanocomposites had a Ti/Si molar ratio of 5:1 and exhibited single-phase rutile with a specific surface area of 269 m² g⁻¹. The addition of acetylacetone (AcAc) during the hydrolysis co-precipitation process played a key role in the growth of well-ordered TiO₂-SiO₂ crystallites since the hydrolysis rate of TiOSO₄ might be retarded due to the complexation of AcAc to the Ti atoms in TiOSO₄. The TMCS-modified TiO₂-SiO₂ nanocomposites exhibited a high root-mean-square (RMS) roughness of 22 nm and good hydrophobicity with a static contact angle of 143.7°, highlighting its potential application as a filler in exterior wall coatings.     

金红石加碳氯化的热力学

运用HSC软件对金红石构成的多元、多相、多反应的复杂体系进行还原平衡组分的计算与分析。通过热力学计算,所得的结果表明：金红石在200℃的较低温条件下可完全转化。金红石加碳氯化反应随着温度的升高和配碳量的增加,体系中CO／CO2摩尔比值增大。只要维持理论配碳量和氯气用量,金红石即可完全转化。     

The superior lithium storage capabilities of ultra-fine rutile TiO2 nanoparticles

The lithium storage capabilities of ultra-fine rutile TiO₂ nanoparticles have been studied. Ultra-fine rutile TiO₂ nanoparticles with only several nanometers in size have been prepared by a modified wet-chemical method with a high yield. Unexpectedly, the rutile TiO₂ nanoparticles with 3 nm in size exhibit superior lithium storage properties. Specifically, they show long term cycling stability upon extended cycling for at least 300 cycles with a capacity loss of only 0.17% per cycle, and good rate capability up to a 30 C rate. The excellent reversible lithium storage capabilities could be attributed to the ultra-fine size giving rise to a very short diffusion path, and the relatively large surface area which provides more sites for lithium insertion.     

基于磁选预富集的湖北枣阳金红石矿石选矿试验

为高效率、低成本、小污染、高效益地开发利用湖北枣阳金红石矿石资源,根据主要脉石矿物有弱磁性,而金红石无磁性的特点,以高梯度中强磁选预富集工艺为基础进行了金红石选矿试验。结果表明：①在磨矿细度为-0.074 mm占88.60%的情况下,1粗1扫高梯度中强磁选抛尾产率可达29.16%,中强磁选精矿金红石含量为3.07%、回收率为89.50%;②高梯度中强磁选精矿经1粗3精3扫闭路浮选,可获得金红石含量64.53%、回收率为82.21%的金红石浮选精矿;③金红石浮选精矿采用高梯度强磁选-焙烧-酸浸工艺提纯,高梯度强磁选背景磁感应强度为1.2 T,焙烧温度为900 ℃、时间为45 min,盐酸浸出的酸浓度为10%、液固比为1∶5、温度为80 ℃、时间为30 min,最终获得金红石含量为87.88%、回收率为71.21%、TiO2品位为90.12%的金红石精矿。与传统的重选预富集工艺相比,采用磁选工艺可减少细粒金红石损失,提高金红石回收率,为国内金红石资源的高效开发利用提供了一种新思路。     

Simple fabrication of rutile titanium dioxide whiskers

Rutile TiO₂ whiskers with a length of 30 μm and a diameter of 1.5 μm were prepared via a facile sintering technique with H₂Ti₄O₉^.0.25H₂O as a precursor under strong acidic condition. Scanning electron microscopy images showed that the whiskers have a uniform shape and a straight rod morphology with a square cross section. X-ray diffraction and transmission electron microscopy combined with a selected-area electron diffraction pattern showed that the TiO₂ whiskers are single crystalline rutile structures grown along the [002] direction and the circumferential faces have four equivalent (110) planes. Compared with rutile microparticles, rutile whiskers exhibit higher activity for the photocatalytic degradation of methylene blue.     

Preparation and thermal reflectivity of nickel antimony titanium yellow rutile coated hollow glass microspheres composite pigment

In order to reduce the urban heat island effect, nonwhite lightweight pigments with high near infrared reflectance were studied. Nickel Antimony Titanium Yellow Rutile pigments (TiNiY) coated hollow glass microspheres (HGM@TiNiY) with core-shell structure were prepared by a novel mixing slurry-sintering method. The Reflective property of HGM@TiNiY/SR composite coating prepared by mixing HGM@TiNiY with silicone resin (SR) was investigated by an UV–Vis–NIR spectrum analyzer. The results showed that the size distribution of TiNiY particles was from 150 to 450?nm with an average size of 230?nm, and the binding mode of TiNiY particles with HGM and the formation mechanism of TiNiY Shell were discussed. The UV–Vis–NIR reflectance of HGM@TiNiY/SR coating was not only better than that of others filled with HGM powders or TiNiY powders alone but also higher than that of the coating filled with the mixture of HGM and TiNiY powders at the same volume ratio. A possible mechanism of HGM@TiNiY/SR coating on thermal reflection was discussed. This clearly indicates that the pigment of HGM@TiNiY with core-shell structure could be applied as a good colour cool pigment.     

攀枝花钛铁矿流态化盐酸浸出的动力学研究

本文探讨了攀枝花钛铁矿流态化盐酸漫出过程中金红石生成的机理和浸出动力学,揭示了表观选择浸出的本质,指出了产物层生成后的浸出速度仍然受未反应核界面化学反应控制。