固氟氯化铵焙烧法从包头稀土矿中回收稀土的动力学

研究了固氟氯化铵焙烧法分解包头混合型稀土精矿回收稀土的动力学.结果表明:固氟焙砂的氯化反应过程符合Bagdasarym提出的区域反应速率模型,氯化反应过程经过了两个串联反应步骤,且反应生成物的核按一个方向长大;反应速率方程遵从Erofeev方程的串联反应步骤模型,反应表观活化能Ea为36.831 KJ·mol-1,过程控制步骤是内扩散控制.     

高温混合障碍空间中的移动机器人路径规划

为了解决高温场景中移动机器人全局路径规划所面临的安全与效率问题,提出高温热源虚拟障碍的定义,建立混合障碍空间模型,将高温场景中的路径规划问题转化为高温混合障碍空间中考虑路径温度代价和长度代价的多目标优化问题. 改进NSGA-Ⅱ算法,通过选取优秀非可行解扩展种群,提高了种群多样性和进化效率,提出新的交叉和变异概率计算方法. 根据种群进化进程和个体代价函数值调整概率,实现了种群前期搜索能力和后期收敛性的平衡. 仿真所得的最优路径结果表明,该改进算法的路径长度代价虽然比原算法和其他改进算法略有增加,但温度代价大幅降低,更有效地避免了陷入局部最优.     

Reaction process of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2

The decomposition reactions of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2 were studied by means of TG-DTA and XRD. The results show that the process of the minerals decomposed by CaO involves two steps. The first step occurs in the temperature range of 425-540 ℃, and the main reactions are bastnaesite decomposition, i.e. REOF reacts with CaO to produce RE2O3 and CaF2, and Ce2O3 is oxidized to CeO2. During this step, CaCO3 is formed at about 500 ℃. The second step takes place in the temperature range of 610-700 ℃, and the reactions are monazite decomposition into RE2O3, Ca5F（PO4）3 and Ca3（PO4）2 by CaO and CaF2. In this process, the decomposition ability is improved because CaO from CaCO3 decomposing has high chemical activity. In calcining process, the new formed Ca5F（PO4）3 restrains fluorine that can escape in form of gaseous compound. The decomposition ratio of the mixed rare earth minerals reaches 90.8% at 700 ℃.     

固液混合铸造Al-40Si合金的显微组织和力学性能

采用固液混合铸造的Al-40Si合金组织细小，合金力学性能明显优于传统铸造和半固态加工合金，并且解决了传统铸造Al-40Si合金铸件难以热加工的问题。在本工艺条件下，当添加平均粒度为120μm的粉末且粉末添加量与合金熔体质量比为1时，Al-40Si合金中的初晶硅平均粒度可控制在30μm以下；材料的室温力学性能为：σb=119.6MPa，σ0．2=105MPa，δ=1．43％。     

高浓度熟料溶出的工艺研究

优化烧结法生产 ,提高产量、节约能耗是氧化铝生产急需解决的问题之一。实现高浓度溶出可以提高精液浓度 ,减少湿法系统物料流量 ,达到提高产能、增加产量、降低成品成本的目的。本文通过对国内外高浓度熟料溶出发展情况和烧结法影响高浓度溶出的因素进行分析研究 ,提出了提高熟料A/S的必要性 ;指出了适合我国条件的熟料A/S大小和生料配方 ;分析了温度和αk 对溶出和分离的影响机理和规律 ;提出了适合高浓度溶出的溶出条件和浓度大小。对生产有一定的指导意义。     

Corrosion of metals and alloys in mixed gas environments at elevated temperatures

The attack of nickel, cobalt, iron, and alloys of these metals containing chromium and aluminum, by gases containing sulfur-oxygen, carbon-oxygen, and nitrogen-oxygen has been studied at temperatures of 600 and 900°C. The degradation of these metals and alloys was characterized by using standard analytical techniques with emphasis on optical metallography. Three types of accelerated degradation were identified for the attack of alloys by gases containing another oxidant in addition to oxygen. One type of degradation occurred because of the formation of reaction products composed of mixtures of phases involving both of the oxidants. Another type resulted from the reaction of second oxidant phases with oxygen. The third form of degradation involved the development of less protective phases due to thermodynamic instabilities. Thermodynamic stability diagrams are used to help account for the effects produced by different elements in the alloys.     

混粉电火花镜面加工技术及应用

利用自行研制的混粉电火花镜面加工装置，对混粉电火花镜面加工影响因素，加工表面性能等进行了深入研究，找出了粉末特性，工件材料，粉末浓度及放电参数等对混粉电火花镜面加工的影响规律，给出了合理的混粉电火花镜面加工工艺条件，以文中确定的加工工艺条件对铸造和压铸模具进行混粉电火花镜面加工，结果表明，该技术能提高模具制造质量，降低工人劳动强度，缩短模具制造周期。     

甲醛法测定铵盐含氮量

对甲醛法测定铵盐含氮量进行了研究，提出采用百里酚酞和酚酞混和指示剂进行测定。该法简单、快速、准确，能满足生产实际和样品检验需要。     

Surface Areas of Nitrated Hydrotalcites

Hydrotalcites in the nitrate form were prepared using microwave irradiation in the hydrotreatment step. The surface area (BET) of nitrated hydrotalcites was evaluated. Solids were characterized by atomic absorption, X-ray diffraction and BET analysis. Thermal pretreatment temperature determined the surface area of the hydrotalcites.     

Oxidation of acrolein on a multicomponent oxide catalyst

Catalytic oxidation of acrolein to acrylic acid has been studied and the optimum composition of the multicomponent catalyst Mo _a V _b Cu _c Fe _d O _x has been found. The reaction kinetics has been measured.