磷酸锌微粉的合成及应用

结合制备磷酸锌微粉的研究工作概述了磷酸锌Zn3(PO4)2.nH2O微粉的合成原理、合成进展。阐明了磷酸锌用作防锈颜料应用机理、用途。提出了间接法合成磷酸锌无需粉碎,产品达到微细级标准的反应条件。     

陶瓷防锈颜料的制备及性能研究

以陶瓷废料为主要原料,复配云母氧化铁、亚磷酸钙等物质,采用机械力/化学包覆的方法进行表面改性,制备了复合陶瓷防锈颜料。对产品的吸油量、水溶物、粒径分布、颗粒形貌等基本物理性能进行了分析,同时采用盐雾试验法对其在环氧涂层的防锈性能进行研究,并与三聚磷酸铝、普通磷酸锌和改性磷酸锌相比较。结果发现:颜料吸油量低、水溶物少;SEM结果显示,颜料粒子中含大量片状结构,可提供良好的屏蔽作用;盐雾试验结果表明,陶瓷颜料具有良好的防锈性能,防锈效果仅次于改性磷酸锌,明显优于普通磷酸锌和三聚磷酸铝。     

氢氧焰燃烧制备纳米Al2O3颗粒及其分散性能

利用多重射流氢氧燃烧反应器,以AlCl3为前驱体制备了具有不同形貌和晶型结构的Al2O3纳米颗粒,表征了其形貌、晶型结构、比表面积、粒径分布等性能,考察了火焰燃烧形式和反应区最高温度等因素对颗粒性能的影响规律. 结果表明,随反应温度升高,Al2O3粒径不断长大,形貌从具有链状结构的不规则颗粒逐渐转变为分散性良好的球形颗粒;同时随反应温度升高和在高温火焰中停留时间延长,晶型由单纯g相逐渐转变为d和d*相. 产品纳米Al2O3颗粒具有较强亲水性,其分散液具有较好的稳定性. 探讨了高温快速反应过程中颗粒和团聚体的生长机理,最终产物的粒径和团聚体形貌取决于各主要影响条件的相互竞争.     

有机酸催化合成微细级磷酸锌

为了改善磷酸锌的分散性，利用有机酸作为催化剂，常温条件下直接合成了磷酸锌。试验结果表明：合成的磷酸锌不用粉碎，粒径直接达到38μm以下，产品粒度分布均匀，白度比普通直接法生产的磷酸锌提高2％，其他各项指标均达到中国的企业标准要求。该工艺无需加热，减少了粉碎工序，节约了能源。     

预烧法制备ZrO2—SiO2—V2O5绿色颜料

利用预烧法制备出了主反射波长在535nm的ZrO2-SiO2-V2O5绿色颜料，并用XRD和UV－V光谱对样品进行了表征。结果显示硅酸锆是所制备颜料的主晶相，其结晶越完整，颜料的色度越好；V2O5是该颜料生成反应的矿化剂，其加入极大的降低了硅酸锆的生成温度，原因在于该反应进行的主要途径是液相反应。     

沉淀法制备超细α-Al2O3

以Al2（SO4）3与（NH4）2CO3为原料，采用液相沉淀法，制备出前驱物碳酸铝铵（AACH），并烧结得到超细Al2O3粉末。通过分析AACH的热重曲线。确定了AACH的高温分解过程；并结合对AACH在不同烧结温度下所得产物XRD图谱的分析，确定了AACH的高温相变过程为：从AACH→AIOOH→Al2O3（无定型）→γ-Al2O3→θAl2O3→α-Al2O3。运用扫描电镜（SEM）对样品的形貌、分散情况进行表征，并估量出α-Al2O3颗粒的粒径大小；测定了α-Al2O3粉末的比表面积，并计算出α-Al2O3颗粒的粒径大小。结果表明，采用该方法能获得平均粒径约为50nm。形貌为球形且分散性良好的α-Al2O3粉体。     

磷酸锌生产工艺研究

磷酸锌是一种性能优良的新型无毒防锈颜料，应用于涂料工业，可配制各种防锈漆，可代替红丹作防锈底漆，代替含铅基料作各类涂料、漆类的基料使用，还可用于钢材的磷化处理，以及医学行业等。目前，中国厂家生产磷酸锌一般采用直接法。介绍一种磷酸锌的新生产方法。该方法引入了间接的生产方法，放宽了原料的质量要求，大大降低了磷酸锌的生产成本。方法如下：将低品位氧化锌加入到R溶剂中，溶解、过滤、精制后与磷酸反应，并用烧碱调其pH，制得磷酸锌精浆，分离、洗涤、干燥后得到成品磷酸锌。滤液与氟硅酸反应使R溶剂再生循环使用，并得到副产物氟硅酸钠。该方法将原直接法生产磷酸锌的固-液反应，改为液-液反应，从而缩短了反应时间。     

防锈颜料磷酸锌生产工艺改进

防锈颜料磷酸锌生产工艺改进梁伟光，解志远（河北省石油化工研究所石家庄市０５００３１）防锈颜料磷酸锌用于配制各种底漆和防腐涂料，也可作为牙科的印膜材料。有一磷酸锌生产厂存在工艺不合理、产品质量不合格、收率低等问题。我们受厂家委托，对其生产工艺进行了改进...     

活性超细含钾磷酸锌的制备及其活化机理的研究

合成了一种含磷酸锌钾和四水磷酸锌的新型活性超细磷酸锌颜料。用XRD、FT-IR和纳米激光粒度仪对其进行表征,测定了溶解度、电导率、pH缓冲区间,从理论上探讨了该颜料的活化机理。实验结果表明:与普通正磷酸锌相比,随着局部pH环境的变化,活性含钾磷酸锌能离解出较多的Zn2 和PO43-离子,改善了正磷酸锌的溶解性、水解性和pH缓冲区间,从而提高抑制阴极剥离反应的能力。     

两种杀菌剂复合干悬浮剂的制备

干悬浮剂是一种高效、安全且环保的农药新剂型,具有优秀的分散性和悬浮稳定性。结合湿法研磨及喷雾干燥技术制备了42%吡唑醚菌酯·霜脲氰干悬浮剂。采用BET、扫描电子显微镜(SEM)、激光粒度仪及接触角仪分别测定了其比表面积和孔体积、形貌及润湿性能。结果显示:制备的干悬浮剂颗粒表面较为粗糙,具有疏松多孔结构及一定的比表面积和孔体积,可以加快颗粒在水中的润湿及崩解分散;在水中分散的颗粒粒径分布较窄且小于2μm;润湿性研究表明,制剂在疏水材料石蜡膜界面上具有较好的润湿铺展性能,最小接触角达到55°。     

钕-铝系稀土色料的研制

通过钕-铝系列色料合成实验,分析不同配比及不同矿化剂等对色料呈色效果的影响,确定最佳工艺方法。对实验结果进行XRD及色度分析,确定其主晶相为钕酸铝,试样的明度均在70以上,色彩鲜艳亮丽。     

Phase equilibrium in binary La2O3-Dy2O3 and ternary CeO2-La2O3-Dy2O3 systems

Cerium oxide doped with oxides of rare earth elements is a multifunctional material, a wide range of uses which is associated with its unique physicochemical properties. Phase diagrams of multicomponent systems are the physicochemical basis for the creation of new materials with improved characteristics.In this work, phase equilibria in ternary CeO₂–La₂O₃–Dy₂O₃ and binary La₂O₃–Dy₂O₃ systems in the whole concentration range were studied. No new phases have been identified in these systems. An isothermal section of the phase diagram of the CeO₂–La₂O₃–Dy₂O₃ system at a temperature of 1500 °С is constructed. No new phases have been detected in the system. It was found that in the studied ternary system solid solutions are formed on the basis of (F) modification of CeO₂ with structure of fluorite type, monoclinic (B), cubic (C) and hexagonal (A) modifications of Ln₂O₃.In the La₂O₃–Dy₂O₃ binary system (1500–1100 °С) three types of solid solutions are formed: based on hexagonal modification A-La₂O₃, monoclinic modification B-Dy₂O₃ and cubic modification C-Dy₂O₃ separated by two-phase fields (A+B) and (B+C), respectively. The boundaries of the regions of homogeneity of solid solutions based on A-La₂O₃ are determined by compositions containing 35–40, 20–25, 15–20 mol% Dy₂O₃ at 1500, 1250, 1100 °C, respectively. From the obtained data it follows that the solubility of Dy₂O₃ in the hexagonal modification of lanthanum oxide is 39 mol% at 1500 °C, 23 mol. % at 1250 °C and 16 mol% at 1100 °C. The limits of existence of solid solutions based on monoclinic B-modification are determined by compositions containing 30–35, 65–60 (1250 °С), 35–40, 55–60 (1100 °С) 40–45, 70–75 (1500 °C) mol% Dy₂O₃.In the studied system, with a decrease in temperature from 1500° to 1100°C, there is a decrease in the solubility of La₂O₃ in the crystal lattice of cubic solid solutions of C-type from 16 to 10 mol%.     

Fe2+/H2O2体系O2生成路径

掌握Fe²⁺/H₂O₂体系O₂的生成路径,可为避免H₂O₂无效分解,开发经济高效的Fe²⁺/H₂O₂体系利用技术指明方向。采用添加自由基捕获剂的方法,探究Fe²⁺/H₂O₂体系内各种自由基对O₂生成速率的影响,进而确定O₂的生成路径。结果表明:Fe²⁺/H₂O₂体系内不会产生大量O₂^-·,O₂^-·不是生成O₂的主要反应物质;O₂^-·被全部捕获后,体系中仍产生大量O₂^-·,但此时无O₂生成,证明生成O₂的反应由·OH和HO₂·两种自由基直接参与。分析认为反应·OH+HO₂·-H₂O+O₂是体系内O₂生成的主要路径。控制Fe²⁺/H₂O₂体系定向生成·OH,抑制HO₂·的产生,是提高Fe²⁺/H₂O₂体系中H₂O₂利用率的有效手段。     

Polycrystalline In2O3 and In2O3/Y2O3 photoanodes

Single crystal In₂O₃ shows promise as a photoanode for the decomposition of water. Because of various difficulties in the preparation of the single crystal material, two simple techniques were developed for the preparation of polycrystalline In₂O₃ anodes. One method involves the thermal decomposition of the nitrate while the other utilizes the chemical vapour deposition technique. Voltammograms and photoresponse spectra of these anodes are compared to the single crystal material. Among other observations, it is noted that the quantum efficiencies of the thermally decomposed films are comparable to the single crystal material. It is also shown that the on-set potential can be shifted to more negative values by forming the mixed oxide In₂O₃/Y₂O₃.     

Na2O-Al2O3-Fe2O3系烧结过程中铝、铁的反应行为

以Al2O3, Fe2O3和Na2CO3为原料,对Na2O-Al2O3-Fe2O3系烧结过程中的反应行为进行了详细研究. 基于溶出率与时间、温度的关系,证明Na2O×Al2O3和Na2O×Fe2O3的生成反应动力学都服从Zhuralev-Lesokin-Tempelman模型,表观活化能分别为186.59和80.92 kJ/mol,表明Na2O×Fe2O3比Na2O×Al2O3在动力学上更易形成;Al2O3易与Na2O×Fe2O3反应形成Na2O×Al2O3和Fe2O3,在1273 K烧结30 min,所得熟料Al2O3溶出率达98.51%;Fe2O3对Na2O×Al2O3的形成有双重作用,在1273 K下可加速Na2O×Al2O3的形成,超过1323 K,促使Na2O×Al2O3分解成Na2O和b-Al2O3,且随着温度升高或时间延长,分解程度增高,从而导致熟料中Al2O3溶出率显著降低.     

H2O2 / O3, H2O2 / UV And H2O2 / Fe2+ Processes For The Oxidation Of Hazardous Wastes

Activated hydrogen peroxide produces very reactive OH-radicals which destroy hazardous contaminants in water. The principles and different methods of activation are described. Results from laboratory studies show the numerous applications of this new technology. A successful scaleup of laboratory tests to an industrial level is discussed. Finally, a cost estimate for treating different types of water with hydrogen peroxide is presented.     

Propylene metathesis over Re2O7/Al2O3-B2O3 catalysts

A series of alumina aluminum borate (AAB) with various Al/B molar ratios were prepared by the coprecipitation method. The supported rhenium oxide catalysts with various contents of Re₂O₇ were also prepared by the impregnation method with perrhenic acid. The catalytic activity and stability of Re₂O₇/AAB catalysts for the reaction of propylene metathesis were tested in a fixed-bed microreactor. It was found that Re₂O₇/AAB is more active, stable and regenerable than Re₂O₇/Al₂O₃ for propylene metathesis. The optimum Al/B molar ratio was found to be in the range of 4–10.     

Barium aluminate hydrates—VI. 2BaO.Al2O3.5H2O and 2BaO.Al2O3.H2O

The compound 2BaO.Al₂O₃.5H₂O has been synthesised and studied by infra-red, X-ray and thermal analytical techniques. The compound of approximate formula 2BaO.Al₂O₃.H₂O forms as a dehydration product. The results are interpreted in terms of the known structure.