Preparation of colloidal Sb2O5 from arsenic-alkali residue

The stable colloidal antimony pentoxide was prepared by oxidation of the mixture of Sb2O3 and Sb2O5 obtained from arsenic-alkali residue by hydrometallurgical process, with hydrogen peroxide as oxidant and phosphoric acid as stabilizer. Effects of main factors were investigated. The theories on thermodynamics, kinetics and electrical double layer（EDL） were used to analyze the experimental phenomena and results. The results show that no＇aging time is the most beneficial to forming colloid, when molar ratio of phosphoric acid to antimony is in the range from 0.8 to 1.0 and 1.0 to 1.3, the particle sizes of sol with the concentration of 10% and 15% antimony pentoxide by mass are both smaller. With increasing concentration of the mixture of antimony oxide from 10% to 20%, the reaction time decreases from 90 to about 30 min, but the optimized range of molar ratio of H3PO4 to antimony increases. The reaction temperature is not the main factor on particle size with the existence of H3PO4 in the temperaturd range from 60 to 90℃.     

Separation of arsenic and antimony from dust with high content of arsenic by a selective sulfidation roasting process using sulfur

The separation of arsenic and antimony from dust with high content of arsenic was conducted via a selective sulfidation roasting process. The factors such as roasting temperature, roasting time, sulfur content and nitrogen flow rate were investigated using XRD, EPMA and SEM–EDS. In a certain range, the sulfur addition has an active effect on the arsenic volatilization because the solid solution phase ((Sb,As)₂O₃) in the dust can be destroyed after the Sb component in it being vulcanized to Sb₂S₃ and this generated As₂O₃ continues to volatile. In addition, an amorphization reaction between As₂O₃ and Sb₂O₃ is hindered through the sulfidation of Sb₂O₃, which is also beneficial to increasing arsenic volatilization rate. The results show that volatilization rates of arsenic and antimony reach 95.36% and only 9.07%, respectively, under the optimum condition of roasting temperature of 350 °C, roasting time of 90 min, sulfur content of 22% and N₂ flow rate of 70 mL/min. In addition, the antimony in the residues can be reclaimed through a reverberatory process.     

五价锑在脱除铜电解液中砷、锑、铋杂质中的作用(英文)

通过向含有45 g/L Cu2+、185 g/L H2SO4、10 g/L As和0.5 g/L Bi的铜电解液中加入Sb(V),研究五价锑对铜电解液中砷、锑、铋杂质脱除作用机理。过滤电解液,采用化学分析、SEM、TEM、EDS、XRD、FTIR等方法对沉淀渣的结构形貌和成分进行表征。结果表明,沉淀渣呈尺寸为50~200μm的不规则块状,其化学成分主要为砷、锑、铋和氧。红外光谱检测表明,沉淀渣主要特征官能团为As—O—As、As—O—Sb、Sb—O—Bi、Sb—O—Sb和Bi—O—Bi。X射线衍射和电子衍射检测结果表明,沉淀渣由AsSbO4、BiSbO4和Bi3SbO7组成。锑酸盐的生成是五价锑脱除铜电解液中砷、锑、铋杂质的主要原因。     

Thermal decomposition kinetics of antimony oxychloride in air

The DTA and XRD techniques were employed to study thermal decomposition mechanism of antimony oxychloride SbOCl in the air. The thermal decomposition reaction occurs in four steps, and the former three steps as: SbOCl (s)→Sb4O5Cl2(s) SbCl3(g)→Sb8O11Cl2(s) SbCl3 (g)→Sb2O3 (s) SbCl3(g). The forth step is the oxidation of Sb2O3 by air, Sb2O3(s) O2→Sb2O4(s). The activation energy and the order of the thermal decomposition reaction of antimony oxychloride in three steps presented in DTA curves were calculated according to Kinssinger methods from DTA curves The values of activation energy and the order are respectively 91.97kJ/mol, 0.73 in the first step,131.14 kJ/mol, 0.63 in the second step and 146.94 kJ/mol, 1.58 in the third steP.     

等离子喷涂铈酸镧热障涂层性能研究

采用固相反应在1 400℃合成了具有萤石结构的铈酸镧(LCO)粉末。考虑到等离子喷涂过程中CeO2挥发高于La2O3,通过对合成粉末原始配比进行调整,制备出的等离子喷涂LCO涂层符合La2Ce2O7化学计量比。LCO涂层在1 400℃下,热处理110h后未发生分解现象。隔热性能测试结果表明,相同厚度的双层结构LCO/YSZ涂层,在1 250℃下隔热性能约为YSZ涂层的2倍。     

La2O3与Sb2O3掺杂钛酸锶钡陶瓷的介电性能及相变（英文）

采用固相法制备La2O3与Sb2O3掺杂的钛酸锶钡陶瓷,研究其介电性能及相变特性。通过X射线衍射法分析体系微观结构并利用扫描电镜观察其表面微观形貌。(La,Sb)共掺杂的钛酸锶钡陶瓷具有典型的钙钛矿结构,且随着Sb2O3掺杂量的增多其平均粒径显著减小。La3+离子以及Sb3+离子均占据钙钛矿晶格的A位。La2O3与Sb2O3添加量的改变显著影响钛酸锶钡基陶瓷的介电常数以及介电损耗。La2O3改性的钛酸锶钡陶瓷其四方?立方相变为二级相变,且居里温度随着La2O3掺杂量的增多向低温方向移动。(La,Sb)共掺杂的钛酸锶钡陶瓷则体现为弥散相变,随着Sb2O3含量的增大而偏离居里-外斯定律越显著。由于Sb3+离子对晶格原位离子的取代使得(La,Sb)共掺杂的钛酸锶钡陶瓷的介电常数最大值下的温度亦随着Sb2O3含量的增大而降低。     

不同前驱体制备的锡锑中间层对Ti／SnO2＋Sb2O3／PbO2电极性能的影响

研究了以乙二醇与柠檬酸反应制得的乙二醇柠檬酸酯溶液、乙二醇、乙醇、正丁醇为前驱体溶剂制备的锡锑中间层对Ti/SnO2 Sb2O3/PbO2电极性能的影响,用XRD、ESEM对不同前驱体制备的锡锑中间层和对应的二氧化铅活性层进行了表征,并用极化曲线法和阳极寿命快速检测法比较了不同前驱体对Ti/SnO2 Sb2O3/PbO2电极的阳极寿命和在1．0mol/L硫酸溶液中的电催化活性的影响。结果表明,不同前驱体溶剂对锡锑中间层的结构和形貌有着显著的影响;以乙二醇与柠檬酸反应制得的聚合前驱体为溶剂制备的锡锑中间层表面致密,锡锑含量相对较高,该中间层的均匀度和平整度明显好于其它3种前驱体。由聚合前驱体中间层制得的Ti/SnO2 Sb2O3/PbO2电极的使用寿命明显提高,但不同中间层前驱体对电极的电催化活性影响不大。     

Sb在铜电解液净化中的应用

介绍了Sb在铜电解液净化中的应用。铜阳极泥分银渣 (含Sb 2 1.35 %)以及由Sb2 O3 和BaSO4 合成的吸附剂能选择性吸附电解液中的As,Sb ,Bi。在确保电解液主要成分不变的情况下 ,不论是分银渣还是合成吸附剂都能从铜电解液中吸附 90 %Bi,80 %Sb及部分As。在讨论吸附机理的同时 ,还研究了阳极铜含Sb对电解过程杂质在阳极泥和电解液之间的分配比例的影响。发现提高Sb在阳极铜里的相对含量可增大电解过程As,Sb ,Bi进入阳极泥的比例 ,从而为铜电解净液寻找了一条方便经济的途径。     

金矿尾砂微晶玻璃的制备

对以金矿尾砂为主要原料制造微晶玻璃进行了研究,根据微晶玻璃的基础组成,选择MgO-Al2O3-SiO2系统为配方依据,从最低共熔点、晶相组成和晶格匹配确定玻璃主成分并优选晶核剂;利用DTA,XRD,SEM等测试手段,研究组成及晶化工艺对析晶性能和物化行为的影响,结果表明：在金矿尾矿中添加适量的镁、铝质材料和网络结构调整氧化物,可获得主晶相为堇青石和尖晶石及顽火辉石固溶体的性能良好的微晶玻璃。     

Separation of arsenic from arsenic—antimony-bearing dust through selective oxidation—sulfidation roasting with CuS

The feasibility of a new method for separating arsenic from arsenic—antimony-bearing dusts using CuS was put forward, in which Sb was transformed into Sb₂O₄ and Sb₂S₃ that stayed in the roasted calcine while As was volatilized in the form of As₄O₆. The factors such as roasting temperature and CuS addition amount were studied using XRD, EPMA and SEM—EDS. CuS has an active effect on the separation of arsenic due to the destruction of (Sb,As)₂O₃ structures in the original dust and the simultaneous release of As in the form of As₄O₆. At a roasting temperature of 400 °C and CuS addition amount of 130%, the volatilization rates of arsenic and antimony reach 97.80 wt.% and 8.29 wt.%, respectively. Further, the high As volatile matter can be used to prepare ferric arsenate after it is oxidized, with this treatment rendering the vapor harmlessness.     

Ni-22Cr-20Co-18W合金在1100℃时氧化膜的演变

采用扫描电子显微镜和X射线衍射分析仪研究了1100℃下Ni-22Cr-20Co-18W合金氧化膜的演变规律。结果显示,在氧化初始阶段,表面形成了Cr2O3,NiO和(Co,Ni,Mn,Cr)3O4混合氧化膜,后者为M3O4型氧化物。长时间氧化后,氧化膜由单层转变为双层,在内层形成连续的Cr2O3膜,在外层形成可以抑制内层Cr2O3挥发的致密NiO氧化膜;同时氧化空位在氧化膜与合金基体界面处形成,并且Al元素的内氧化也在该处发生。     

铜电解液净化中铜砷的分离与回收(英文)

经二氧化硫还原、蒸发结晶,使铜电解液中铜、砷、锑和铋得到有效去除。结晶产物经过溶解、氧化、中和、沉淀、过滤和蒸发结晶,得到三氧化二砷和硫酸铜。当采用SO2将铜电解液中As(Ⅴ)充分还原为As(Ⅲ),并加热蒸发浓缩铜电解液中硫酸浓度至645g/L时,铜电解液中铜、砷、锑和铋的去除率分别为87.1 %,83.9 %,21.0 %和84.7%。在温度30℃,将65g结晶产物溶于200mL自来水时,砷的去除率为92.81%。将所得滤液在如下条件下净化:n(Fe):n(As)为1.2,双氧水为理论用量的19倍,氧化温度为45℃,氧化时间为40min,终点pH为3.7,净化后蒸发浓缩结晶,所得硫酸铜溶液中硫酸铜含量达到98.8%。     

Y2O3含量对SiO2-Al2O3-B2O3-K2O-Li2O系统微晶玻璃的析晶及性能的影响

以SiO2-Al2O3-B2O3-K2O-Li2O为玻璃组成,P2O5和ZrO2为复合成核剂,Sb2O3为澄清剂,Y2O3为添加物,通过传统熔体冷却方法制得了该系统基础玻璃.利用DSC、XRD、SEM及性能测试等手段,研究了Y2O3含量的变化对玻璃析晶行为、析出晶相种类、晶粒尺寸、晶粒分布以及微晶玻璃的力学性能的影响.研究结果表明:随着Y2O3含量的增加,玻璃的析晶峰值温度升高,且析晶峰也逐渐变宽、变钝;Y2O3的加入并不影响微晶玻璃中主晶相的组成,但对其微观结构有明显影响;当Y2O3含量低于2.0%(摩尔分数)时,微晶玻璃的抗弯强度随Y2O3含量增加而增加;当Y2O3含量为2.0%时,获得微晶玻璃的抗弯强度值最高,达到217 MPa;当2.0%≤x(Y2O3)≤2.5%时,抗弯强度反而降低;当Y2O3含量为2.5%时,获得的微晶玻璃具有良好的半透明性,并具有较好的力学性能(抗弯强度为198 MPa);与一步法热处理相比,采用两步晶化热处理有利于提高微晶玻璃的力学性能.     

Nucleation/growth mechanism of electrocrystallization for As–Sb alloy in hydrochloric acid system

The initial electrocrystallization of As–Sb alloy on glass carbon (GC) electrode in hydrochloric acid system was studied via cyclic voltammetry (CV) and chronoamperometry measurements. Current transients were presented in dimensionless formation, which showed that the initial nucleation/growth process of As–Sb alloy followed three-dimensional nucleation model with diffusion-controlled growth. Relevant nucleation parameters were calculated by analyzing related current transients. Particular attention was paid to the effect of Sb(III) concentration on the nucleation process during the co-electrodeposition. The quantitative results showed that Sb(III) played a positive effect on enhancing the nucleation rate of As–Sb alloy, leading to the evolution of alloy surface morphology from grain structure to compact layer structure.     

Removal of cobalt from zinc sulphate solution using rude antimony trioxide as additive

1　ＩＮＴＲＯＤＵＣＴＩＯＮＲｏａｓｔ ｌｅａｃｈ ｐｕｒｉｆｉｃａｔｉｏｎ ｅｌｅｃｔｒｏｗｉｎｎｉｎｇｐｒｏｃｅｓｓｉｓｔｈｅｍｏｓｔｃｏｍｍｏｎｍｅｔｈｏｄｆｏｒｚｉｎｃｐｒｏｄｕｃｔｉｏｎｉｎｔｈｅｗｏｒｌｄ[1 ] .Ｔｈｅｒｅｍｏｖａｌｏｆｃｏｂａｌｔｆｒｏｍｚｉｎｃｓｕｌｐｈａｔｅｓｏｌｕ ｔｉｏｎｂｙｃｅｍｅｎｔａｔｉｏｎｈａｓｂｅｅｎｔｈｅｆｏｃｕｓｏｆｒｅｓｅａｒｃｈｆｏｒｍｏｒｅｔｈａｎ 2 0ｙｅａｒｓｉｎｔｈｅｈｙｄｒｏｍｅｔａｌｌｕｒｇｙｏｆｚｉｎｃ[1 ,2 ] .Ｔｈｅｐｒｅｓｅｎｃｅｏ…     

超声掺Bi二氧化铅电极电氧化降解2-氯苯酚研究

目的提高Pb O_2/Ti的使用寿命、对目标反应物的电氧化催化活性及选择性。方法以覆有Sn O_2+Sb_2O_3的Ti网为阳极,分别在Pb(NO_3)_2、Na F混合溶液及Pb(NO_3)_2、Na F、Bi(NO_3)_3组成的掺Bi混合溶液中,在电沉积液p H=2、60℃、电沉积电流密度为0.04 A/cm~2的条件下,进行常规电沉积及超声电沉积1 h,制备出Pb O_2/Sn O_2+Sb_2O_3/Ti,Bi-Pb O_2/Sn O_2+Sb_2O_3/Ti,Pb O_2(ultrasonic)/Sn O_2+Sb_2O_3/Ti,Bi-Pb O_2(ultrasonic)/Sn O_2+Sb_2O_3/Ti 4类二氧化铅电极。在硫酸溶液中测定其加速寿命,用稳态极化曲线分析电催化性及选择性,以2-氯苯酚的电氧化降解反应为模型反应,考察电解2-氯苯酚废水的处理效果,用X射线衍射仪和电子扫描电镜表征沉积层晶相和形貌。结果 Bi-Pb O_2(ultrasonic)/Sn O_2+Sb_2O_3/Ti的加速寿命比Pb O_2/Sn O_2+Sb_2O_3/Ti提高了54%。电氧化降解2-氯苯酚溶液4 h后,以掺Bi二氧化铅电极为阳极,相比于二氧化铅电极,对2-氯苯酚的脱除率提高了19%,槽压降低了7%,稳态极化曲线和电氧化降解2-氯苯酚溶液试验反映了相同的结论。结论超声波环境和Bi掺杂显著提升电极的性能,掺Bi的二氧化铅沉积层表现出较高的电催化性和电氧化2-氯苯酚的选择性,超声电沉积二氧化铅能增大电极比表面积,提高电极的表观催化活性和电极加速寿命。     

高砷铅阳极泥水蒸气焙烧脱砷实验研究

针对目前工业上难处理的高砷铜阳极泥 ,作者提出在水蒸气气氛中焙烧脱砷的新工艺。实验主要对反应气氛、焙烧温度、焙烧时间等影响因素进行了系统考查。结果表明 ,在水蒸气气氛下焙烧高砷铅阳极泥 ,脱砷率≥ 87% ,焙砂含砷 <3% ,脱砷效果明显好于空气气氛。同时 ,通过XRD分析 ,对焙烧脱砷过程中的物相变化及反应机理进行了探讨。     

Preparation of colloidal Sb_2O_5 and its stability

1　INTRODUCTIONColloidalantimony pentoxideisanewinorganicflameretardant .Itcanbeusedinrubber,plastics,fiber ,textile ,carpet,paint ,paperandprintedcircuitboardbe causeofitsflameretardingabilityandotherexcellentpropertiessuchashighdispersion ,lowcoloringintensityandhighheat stability[15] .Althoughmoreandmoreap plicationsofcolloidalantimonypentoxidearefoundintheindustry,therearelackofdetailedstudiesonprepara tionandstabilityofcolloidalantimonypentoxideex ceptsomepatentsabouttechnologicalproc…     

Synthesis of GdF3 from the Gd2O3-NH4HF2 system

GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature,and the products were GdNH4F4,NH4F,NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment,accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps： synthesis,decomposition,and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained： synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.     

Microscopic Study of the Phase Transformation During the Oxygen-Enriched Direct Smelting of Jamesonite Concentrate

Samples of partially oxidized jamesonite particles and crude lead-antimony alloy from oxygen-enriched direct smelting of jamesonite concentrate have been characterized by electron probe microanalysis (EPMA), x-ray diffraction (XRD), and scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). It was shown that the Fe diffused outward from the center of the jamesonite to the outermost layer forming an iron-riched sulfide coat, while the behaviors of Pb, Sb, and Cu were contrary to that of Fe. The formation of FexSbyS impeded the oxidation and volatilization of antimony compounds. As a result, more antimony was retained in the grain during the oxidation process and then transformed into the crude lead-antimony alloy. The microprobe analysis of the metallic core of the partially oxidized jamesonite grain revealed that the PbS was preferentially oxidized to give metals. Investigations on crude lead-antimony alloy indicated that impurities of iron and copper presented as FeSb₂, FeSb, and Cu₂Sb forms.