撞击流反应器制备纳米二氧化钛的实验研究

以TiCl4和(NH4)2SO4为原料,在撞击流反应器中用沉淀法制备了纳米二氧化钛。研究了工艺参数对粒径的影响,结果表明,反应物浓度1.2 mol/L,pH值为3,反应温度70℃,转速600 r/min的条件下,制得的沉淀物经600℃高温焙烧3 h,可得粒径为11.30 nm的二氧化钛颗粒,粒径均匀,不团聚。     

钛白渣提纯制备电池级硫酸亚铁工艺技术研究

以某钛白粉生产企业副产钛白渣为原料,选用复合沉淀剂代替传统常用化学沉淀剂,采用一步沉淀法去除杂质,提纯制备电池级高纯硫酸亚铁产品,可作为磷酸铁锂生产原料,为钛白渣的利用提供了新途径。研究结果表明：选用氟化氢铵与还原铁粉按一定质量比配制的复合沉淀剂[m（氟化氢铵）:m（还原铁粉）=3.6:1],控制反应条件：反应温度为60 ℃、反应时间为2 h、沉淀剂用量为钛白渣处理量的2.67%（质量分数）、搅拌速度为300 r/min、反应液中Fe²⁺浓度为1.37 mol/L,最终得到产品纯度为99.98%,镁、钛杂质脱除率均达到99%以上,XRD结果表明产品为七水硫酸亚铁。     

纳米TiO_2光触媒的制备及应用研究

以尿素为均匀沉淀剂、硫酸氧钛为原料制备粒径可控、分散性良好的纳米二氧化钛粉体。系统地研究了制备条件对粒径大小、粒子形貌的影响,探讨了均匀沉淀法形成纳米二氧化钛粉体的机理、晶体成长和晶型转化动力学以及光催化性能,并列举了作为光触媒的应用实例。     

氨水沉淀法由含钛滤液提取二氧化钛

以含钛高炉渣为原料,经硫酸铵熔融法得到含钛滤液,然后以氨水为沉淀剂,控制pH值使钛水解,水解产物经600℃煅烧2 h得到二氧化钛。考察了螯合剂的加入量、溶液pH值和反应时间对钛沉淀率的影响,实验结果表明:反应过程中铁与钛发生共沉淀,造成二氧化钛产物中的铁含量过高。EDTA几乎完全抑制了铁的沉淀,明显降低了二氧化钛产物的全铁含量;2-羟基丙烷-1,2,3-三羧酸的加入降低了产物中二氧化硅的含量,提高了产物中二氧化钛的含量。当2-羟基丙烷-1,2,3-三羧酸与硅的摩尔比为1,EDTA与铁的摩尔比为3,pH值为2.0,反应时间为90 min时产物中二氧化钛的含量为96.35%。     

燃煤电厂废弃SCR脱硝催化剂元素回收研究进展

随着选择性催化剂还原法（SCR）脱硝技术在国内的普及以及SCR脱硝工程的大量建设,废弃SCR脱硝催化剂的高效处置已引起了广泛关注,针对高附加值成分的元素回收是较为合理的处置方案。本文总结了目前关于废弃SCR脱硝催化剂3种主要元素Ti、V、W（或Mo）回收的主要技术方案,其中Ti元素的回收主要是通过钠化焙烧法或浓碱浸出法首先分离Ti元素,而后通过酸洗法回收获得二氧化钛;V元素的回收方法主要包括铵盐沉淀法、萃取法和电解法,从而得到五氧化二钒或者偏钒酸铵;W元素的回收方法主要包括钙盐沉淀法、钠盐结晶法和酸沉法,从而得到三氧化钨。在此基础上,对各技术方案进行了比较,为开发高效合理的元素回收技术提供依据,并指出后续研究中还需要优化酸洗法回收Ti元素的酸洗条件以及V、W元素的纯化技术,从而进一步提高回收产品的纯度。     

提钪废液制备高纯碳酸锰

本文研究了以钨渣提钪废液为原料,软锰矿为氧化剂,菱锰矿为中和剂,制备高纯碳酸锰的工艺方法。探讨了反应温度、菱锰矿用量与反应时间对锰浸出效果的影响,以及水合二氧化锰吸附法中过氧化氢用量对除硅效果的影响。硫酸锰溶液经过水解法除铁、铝,硫化铵法除重金属,水合二氧化锰吸附法除硅,氟化铵法除钙、镁、稀土元素,最后碳酸氢铵沉淀获得高纯碳酸锰。     

云母钛珠光颜料的形成机理研究

阐述了云母钛的形成机理，即云母依靠静电引力吸附[Ti(H2O)6]^4 形成双电层，双电层上的[Ti(H2O)6]^4 发生水解引起多核络合物生长为水合二氧化钛，水解的水合二氧化钛与云母产生异质颗粒间的互凝而形成云母钛。     

快速测定钛白粉中铁含量方法的优化

在硫酸铵的作用下,控制溶解温度,钛白粉能够缓慢溶解在浓硫酸中,而在一定的酸度条件下,三价铁与硫氰酸铵能够快速形成稳定的红色络合物,由此确立了测定钛白粉中微量铁的方法。该测定方法具有快速、简便、重现性好、准确度高的优点,适用于钛白粉成品中铁含量的分析。     

纳米固体超强酸SO2-4/Fe2O3的催化性能

In order to minimize the pollution of ferrous sulfate, a by-product of titanium dioxide, and increase the yield of synthetic ester, the SO4^2-/Fe2O3 nanosolid superacid has been produced by chemical precipitation and its micrographs was determined by SEM. The effect of preparation conditions of SO4^2-/Fe2O3 nanosolid superacid on catalysis synthesis butyl acetate and synthesis conditions of butyl acetate were studied. From experimental data, as compared with liquid acid, SO4^2-/Fe2O3 nanosolid superacid showed higher catalytic performance in catalytic synthesis of butyl acetate, and the yield of butyl acetate was obviously increased in the same reaction time.     

响应面法优化含锰钛白废水制备碳酸锰的工艺

以硫酸法钛白粉生产过程产生的含锰废水为原料，以碳酸氢铵溶液为沉淀剂, 十二烷基硫酸钠为添加剂，采用液相沉淀法对废水中的锰进行资源化回收。在单因素实验基础上，采用响应面法中的Box-Behnken Design优化实验设计，分别考察了反应温度、过量系数、pH和陈化时间四因素对碳酸锰沉淀率的影响，建立了响应值与影响因素间的回归方程，并确定了优化条件为：反应温度33.3℃、过量系数1.06、pH=7.2、陈化时间2.0h，在该条件下锰的沉淀率预测值为99.30%，相应的实验值为98.90%，预测值与实验值相对误差仅0.4%，表明响应面法所建立的预测锰沉淀率的模型可靠；所得产品经电感耦合等离子体发射光谱仪（ICP-AES）分析锰含量为43.53%，符合工业碳酸锰（HG/T 4203—2011）质量标准中对碳酸锰纯度的要求。研究结果为含锰废水的资源化回收提供了新思路。     

电感耦合等离子发射光谱测定钛白粉中的二氧化钛

用电感耦合等离子体发射光谱(ICP-AES)法测定钛白粉中的二氧化钛,试样用硫酸和硫酸铵加热分解,盐酸溶解盐类。通过与GB1706-2006结果对照,表明,方法的RSD为0.45%。     

Structural modifications of nanostructured ceria CeO2,xH2O during dehydration process

Hydrated nanostructured cerium dioxide CeO₂, xH₂O (hydrated nanoceria) has been synthesized in room conditions via a precipitation route. This hydrated nanoceria phase has been subjected to thermal decomposition in the temperature range from 25 °C to 800 °C. At least three decomposition steps have been observed in thermal and thermogravimetric analyses. Three different samples of cubic nanoceria respectively obtained at room temperature (RT-nanoceria), 80 °C (80-nanoceria) and 600 °C (600-nanoceria) have been studied by X-Ray diffraction, Raman spectroscopy and scanning electron microscopy analyses. The analyses of X-ray diffraction profiles and Raman vibrational bands have clearly shown that dehydration is accompanied by increasing crystallite size, lattice parameter contraction. The cubic structure of hydrated RT-nanoceria might be associated with a complex chemical formula unit involving Ce⁴⁺, Ce³⁺ mixed valences, oxygen vacancies, lattice and surface water and OH^? proton species.     

由钛白生产副产物绿矾制备氧化铁红及硫酸铵的研究

研究了以钛白粉厂副产物绿矾为原料,采用湿法同时生产氧化铁红和硫酸铵的制备工艺,考察了煅烧温度、煅烧时间及气氛对氧化铁红产品的影响,并进行了经济效益分析。     

钛液水解工艺对金红石二氧化钛消色力的影响

以工业钛液为原料,采用外加晶种常压水解工艺制备了金红石型二氧化钛,研究了水解钛液的组成和操作参数对二氧化钛消色力的影响。实验结果表明：二氧化钛消色力（Tcs）和蓝相光谱值（Scx）随晶种添加量的增加先增大后减小,随判灰延时时间的增加先增大后减小,随钛液F值的增加先稍有增加后明显降低,随钛液二氧化钛质量浓度的增大而增加。在钛液F值（游离硫酸加上与钛结合的硫酸之和与二氧化钛质量浓度的比值）为1.90左右、铁钛比（铁元素与二氧化钛质量浓度的比值）＜0.5、二氧化钛质量浓度为190~200 g/L、晶种添加量（晶种中二氧化钛质量与对应批次水解浓钛液中二氧化钛质量的比值）为2.0%~2.2%、灰点为“基点+20 min”、熟化时间为0~30 min、稀释水在二沸后100 min加入的条件下进行水解,经过一次洗涤—漂白—二次洗涤—盐处理—煅烧,所得金红石型二氧化钛的消色力更好。     

纳米级二氧化钛的制备、成膜及消除室内污染

采用溶胶-凝胶法,以钛酸丁酯为原料制备纳米级二氧化钛.研究了水分含量、加水速度、溶剂用量、pH值以及反应温度等因素对二氧化钛制备的影响,优化了制备工艺条件.利用不同的成膜剂制成二氧化钛薄膜,对该膜进行了消除室内甲醛及芳香化合物污染的检测.     

纳米固体超强酸SO2-4/Fe2O3的催化性能

引言 目前的工业催化反应大部分属于酸催化反应,而固体超强酸[SO2- 4/MxOy(M代表金属)]和液体酸相比,具有活性和选择性高、不腐蚀、无污染及产物易分离等特点[1],是一种较理想的绿色催化剂.自1979年Hion首例制备SO2- 4/Fe2O3固体超强酸以来,它就成为人们研究的热点[2～5],并广泛地应用于石油炼制和有机合成工业.但有关纳米固体超强酸的研究报道还不多.     

Simultaneous preparation of TiO2 and ammonium alum,and microporous SiO2 during the mineral carbonation of titanium-bearing blast furnace slag

In this study, a route for simultaneous mineralization of CO₂ and production of titanium dioxide and ammonium alum, and microporous silicon dioxide from titanium-bearing blast furnace slag (TBBF slag) was proposed, which is comprised of (NH₄)₂SO₄ roasting, acid leaching, ammonium alum crystallization, silicic acid flocculation and Ti hydrolysis. The effects of relevant process parameters were systematically investigated. The results showed that under the optimal roasting and leaching conditions about 85% of titanium and 84.6% of aluminum could be extracted while only 30% of silicon entered the leachate. 84% of Al³⁺ was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%. About 85% of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9 (AEO-9) to yield a microporous SiO₂ material (97.4 wt%) from the crystallized mother liquor. The Al- and Si-depleted solution was then hydrolyzed to generate a titanium dioxide (99.1 wt%) with uniform particle size distribution. It was figured out that approximately 146 kg TiO₂ could be produced from 1000 kg of TBBF slag. Therefore, the improved process is a promising method for industrial application.     

Water-soluble polymers as retention aids in a model papermaking system. II. Poly(vinylpyridines)

Three poly(4-vinylpyridines) and a poly(2-vinylpyridine) were studied for their effectiveness at increasing the retention of titanium dioxide a model papermaking system at pH 3.8. All the polymers are very efficient retention aids and do not greatly increase the time for the paper sheet to be formed. They are well adsorbed by both cellulose fibers and titanium dioxide. Although fiber suspensions are weakly flocculated by the poly(vinylpyridines), pigment suspensions are stabilized. Flocculation studies on mixed suspensions show that the poly(vinylpyridines) have a powerful heterocoagulation effect which mirrors the retention results. Some results are also reported in which the pH is brought to 6.5; under these conditions, polymer adsorption and its consequent effects compete with polymer precipitation.     

纳米二氧化钛薄膜的制备及特性研究

纳米二氧化钛薄膜由于具有优良的光催化活性而受到人们的重视。采用阳极电沉积的方法在ITO基体上制备二氧化钛钠米薄膜。研究了阳极电流密度和沉积时间对纳米二氧化钛薄膜结构和附着力的影响，利用扫描电子显微技术和X射线衍射技术分析了二氧化钛薄膜的表面形貌和组织结构，探讨了其光催化活性和亲水性。结果表明，纳米二氧化钛薄膜是由纳米级的颗粒组成，颗粒间存在纳米级小孔，该薄膜对于波长为400－700nm的可见光是透明的，具有优良的光催化活性和亲水性。     

Structure and Physical Properties of Borosilicate as Potential Bioactive Glasses

Borosilicate bioactive glasses containing titanium dioxide were prepared and investigated. The corrosion behavior of samples was examined for all samples upon immersion in phosphate solution. The erosion of the outer surface and ion exchange processes of the glass with the surrounding solution were studied by measuring the weight loss. Results were compared with samples that do not contain titanium dioxide. The final result of the reaction is the precipitation of hydroxyapatite. Characterization of the glasses was carried out by FTIR (Fourier transform infrared) absorption spectra before and after immersion in phosphate solution. The different crystalline phases and crystallographic parameters were explored using X-ray diffraction (XRD) analyzes and all indicate the precipitation of hydroxyapatite. A scanning electron microscope (SEM) is used to observe the morphological changes of the surfaces upon immersion. The atomic ratio of the final result product was obtained by the energy dispersive x-ray analysis (EDX) unit attached to the SEM. Changes in pH of the leaching solution were measured and evaluated. All measurements confirm that the studied glass has a high degree of biological activity which makes it very suitable for the field of biomaterials and other various medical applications.