矿物氧化法制备氢氧化钡新工艺研究

用低品位软锰矿氧化处理硫化钡水溶液可直接制取氢氧化钡，产品收率可达９５％以上。     

二氧化锰法制氢氧化钡的研究

<正> 许多化工产品生产中,为有效地除去硫酸根离子,常采用化学法,借助于与钡离子生成难溶的硫酸钡沉淀而滤除。钡盐系列产品之一的氢氧化钡常被选用,因为它不会引入可能妨碍产品质量的阴离子(如Cl~-、NO_3~-、S~(2-)等)。市售工业氢氧化钡通常为八水物(含水45%),氯化物亦较高(如Cl~-0.25～0.30%)。由于目前国内工业生产以烧碱法为主,故成本较高,而具有发展前途的离子交换法尚待付诸工业生产。据文献报道氢氧化钡可用软锰矿粉或含二氧化锰的废料处理硫化钡料液而制得,     

硫酸锌氧化除杂新工艺

立德粉的化学组成为硫化锌和硫酸钡,是由纯净的硫酸锌溶液和硫化钡溶液在反应容器中通过复分解反应而生成的白色沉淀混合物。传统的硫酸锌净化工艺是通过氧化还原反应,除去溶液中的铁、锰、镉、镍等杂质,其中氧化反应是以高锰酸钾或漂白粉作为氧化剂将溶液中的低价铁、锰离子氧化为高价,在保持pH5.2～5.6的弱酸性环境中     

相转变法由软锰矿制备磁性四氧化三锰工艺

为了降低四氧化三锰的生产成本，介绍了以价格低廉的软锰矿为原料，使用相转变法制备四氧化三锰的基本原理和工艺过程。在实验条件下，以投料比m（软锰矿）：m（硫铁矿）：V（硫酸）=10g：9g：3．5mL，液固质量比10：1，反应时间5h，反应温度90℃进行反应，经净化处理后可制备出纯净的硫酸锰溶液。进一步向溶液中滴加一定浓度的氨水溶液，控制溶液pH在10左右，过滤洗涤后，溶液在50℃下，通入空气反应3．5h，再经过滤洗涤、干燥和粉碎，可制备出高纯度的四氧化三锰，反应总收率达90％以上。     

利用硫化钡和氢氧化钠一步生产氢氧化钡和硫化钠的方法

本发明提供利用硫化钡和氢氧化钠一步生产氢氧化钡和硫化钠的工艺。即利用工业硫化钡与烧碱液直接反应,生产出氢氧化钡产品及副产品硫化钠。该工艺包括以下方法步骤:将硫化钡原料溶浸、浸出液除渣后加热保温、测定钡离子的物质的量、加入烧碱物质的量为钡离子1～3倍的碱液、将     

硫化钡氧化的动力学研究

前言由重晶石还原焙烧所得的硫化钡,加水溶解后,通入空气进行氧化,可以直接转化为氢氧化钡。这是一条较新的工艺路线。较之国内现有的几种生产方法,可以省掉大量酸、碱,从而大大地降低了产品的成本,并且有利于连续化生产,其副产物也可综合利     

大颗粒硫酸钡的制法

过去工业上制取硫酸钡的方法是,用硫化钡溶液和硫酸钠溶液进行反应,可用硫酸代替硫酸钠溶液。另外还有用硝酸钡、氯化钡或氢氧化钡等水溶性钡盐溶液和硫酸或硫酸钠溶液反应的方法。上述方法制得的硫酸钡颗粒度小于     

钛白废酸-软锰矿-硫铁矿制备高纯硫酸锰

研究以硫铁矿为还原剂,在钛白废酸中湿法还原软锰矿制备硫酸锰的工艺过程。探讨反应温度、反应时间、酸矿比和矿浆浓度等因素对硫酸锰浸出率的影响。实验结果表明：在反应温度为95 ℃、反应时间为2.5 h、硫铁矿与软锰矿（以锰计）的质量比为0.95～1.0、硫酸与软锰矿（以锰计）的质量比为1.30、矿浆质量分数为28%～30%的条件下,硫酸锰的浸出率达到95%以上。通过加入碳酸钙中和浸出溶液使其pH为5～6,以除去溶液中的铁、钛、铝等杂质;加入自制硫化锰以除去溶液中的重金属离子;加入二氟化锰以除去溶液中的钙镁离子等。所得溶液经陈化、过滤、浓缩和结晶后得高纯一水硫酸锰,产品纯度为99%以上。     

铜-镧-铈化合催化剂在氨溶液的湿法催化氧化中的活性

催化剂Cu-La-Ce被研究应用于浓度为40～1000mg／L的氨溶液在滴流床上的催化氧化反应，其催化剂为铜、镧、铈不同摩尔浓度的共沉积物，反应结果显示了催化剂铜-镧-铈不同的摩尔比对湿法催化氧化反应中氨转化率的影响。在缺少催化剂的情况下，氨溶液的湿法氧化反应很难进行，而当湿法氧化反应在温度503K、氧的分压为4．0MPa，催化剂Cu-La-Ce的摩尔比为7：2：1的条件下，其氨的转化率达到95％，氨催化反应在动力学上可以被认为是零级。另外，研究人员也研究了当反应空速在9h^-1以下时，氨的初始浓度和反应温度对其湿化催化转化反应的影响。     

碳酸钡生产中的三废处理

碳酸钡被广泛用于电视机显像管玻壳、光学玻璃、颜料、陶瓷、油漆、磁性材料等行业，是一种重要的无机化工产品之一。其生产方法大都是将重晶石和煤按一定比例混合，经破碎送入回转炉或反射炉内，在900～1200℃下焙烧还原得硫化钡黑灰，然后浸取配制为硫化钡溶液，通入二氧化碳经碳化制得碳酸钡浆，再经脱．硫、过滤、烘干、包装而得碳酸钡产品。在此生产过程中产生了大量的三废，污染环境。综合治理三废，一方面既要在三废产生后进行治理利用，变废为宝，最终达到国家规定的排放标准，另一方面更要在碳酸钡生产的先进工艺和设备上下功夫，提高物料利用率，实行全过程污染控制。     

Effects of Excess Barium Ions on Aqueous Barium Titanate Tape Properties

The effects of excess free barium ions in aqueous barium titanate slip on the resulting BaTiO₃ tape properties were investigated in terms of the slip behavior, green/sintered tape density and morphology, and dielectric properties. The excess free barium ions expressed by means of the Ba/Ti ratio adversely affected most tape properties. Increase in the slip viscosity, green porosity, and agglomeration along with a decrease in mechanical properties and green/sintered density were found with the increase in the Ba/Ti ratio. However, dielectric permittivity was increased with increase in the Ba/Ti ratio. An effort was made to correlate these phenomena with Ba²⁺ leaching in water for realistic multilayer ceramic capacitor applications.     

钡盐产品的研究开发和展望

介绍了国内外主要钡盐产品的研究开发现状和生产状况 ,并且阐述了主要的钡盐产品的应用前景和市场动态趋势     

含钡废渣的综合利用

介绍了钡渣制氯化钡、钡渣制硝酸钡、钡渣制砖的生产方法和工艺条件，指出钡渣的综合治理，有巨大的经济效益和社会效益，发展前景非常广阔。     

硫酸钡合成试验

介绍了在结合立德粉的生产中，采用新工艺生产沉淀硫酸钡，同时副产品供立德粉使用，解决废水污染问题。     

氯化钡生产工艺改进

介绍了盐酸法生产氯化钡的原理及影响反应的主要因素,论述了对原料和工艺路线方面的改进内容。     

Anomalous Grain Growth in Donor-Doped Barium Titanate with Excess Barium Oxide

Grain growth and semiconductivity of donor-doped BaTiO₃ceramics with an excess of BaO and additions of SiO₂or B₂O₃were studied. The microstructures and electrical measurements on sintered samples revealed that their electrical properties are related to the microstructure development of the sintered samples. Samples heated with an excess of BaO developed a normal microstructure during sintering, as a consequence of normal grain growth (NGG), and were yellow and insulating. In contrast, samples with an excess of BaO and an addition of SiO₂or B₂O₃exhibited anomalous grain growth (AGG) and were dark blue and semiconducting after sintering. When some BaTiO₃seed grains were embedded in a sample of donor-doped BaTiO₃with an excess of BaO (without SiO₂or B₂O₃), AGG was observed, i.e., some seed grains grew into large grains and were blue and semiconducting. An explanation is given for why AGG is responsible for the oxygen release and the formation of semiconducting grains in donor-doped BaTiO₃and not NGG.     

XPS Analysis of Submicrometer Barium Titanate Powder

A commercial submicrometer BaTiO₃ powder was analyzed using X-ray photoelectron spectroscopy. The analysis revealed the powder surfaces to be covered with a layer of physisorbed H₂O and chemisorbed –OH ions. A BaCO₃ residual not detected with XPS was shown to be present in the powder using X-ray diffraction, suggesting that the carbonate takes the form of discrete particles rather than of a continuous surface layer. A relaxed surface phase detected in previous XPS analyses of bulk BaTiO₃ was also shown to be present. Depth profiling revealed the powder surfaces to be Ti-rich, confirming the presence of a phase, or phases, to stoichiometrically balance the barium carbonate.     

间接酸碱滴定法快速测定钡含量

研究了酸碱滴定法间接测定钡含量的方法.方法基于被测Ba2+与定量的K2CrO4溶液反应形成BaCrO4沉淀,剩余的CrO2-4以溴甲酚绿为指示剂,用HCl标准溶液滴定而间接测定钡.方法简便快速,应用于钡盐及重晶石中钡的测定,结果满意.     

Flextensional Barium Strontium Titanate Actuators

This paper describes the performance of the cymbal flextensional transducer using Dy-doped barium strontium titanate (BST) as the driver material. BST was first characterized for its dielectric and loss behavior as a function of temperature and electrical bias field. With no electrical bias, the transition temperature was measured to be near 20°C and have a dielectric constant >20 000. The strain of a BST disk was then measured and compared with other ceramics. At room temperature the strain and average effective piezoelectric d ₃₃ of this non-lead composition was slightly larger than Navy type I lead zirconate titanate (PZT-4) ceramic. The strain/field behavior was also measured as a function of temperature. Cymbal capped BST ceramic was found to have an amplified displacement of 28×, also very similar to type I ceramic. The stiffness of BST was found to be tunable by dc voltage and 2 to 3 times larger than that of PZT. This material has promise for applications in actuators and transducers with large generative force.     

Barium Carbonate Phase on the Surfaces of Barium Titanate Particles and in Situ Transmission Electron Microscopy Observation of Its Decomposition

A BaCO₃ phase is found on the surfaces of hydrothermally synthesized BaTiO₃ particles; it occurs as aggregates or small protuberances. A small proportion of the phase decomposes to BaO crystallites when heated by a convergent electron beam in a transmission electron microscope. The BaO and BaCO₃ crystallites disappear when they are irradiated successively by the convergent electron beam. The BaO crystallites and the BaCO₃ phase sublimate and/or react with BaTiO₃ crystals whose surface layers are deficient in Ba²⁺ ions.