银矿浸取技术

银矿浸取过程中加入间硝基苯磺酸钠(MS)强化传质和阴极反应,从而提高了银的氰化浸取反应速率。采用收缩未反应芯模型,较好地描述了银的氰化浸取反应过程。在MS存在下,浸取反应仍具有明显的扩散控制特征。建立了银的浸取反应宏观动力学模型,其计算值与实验值的平均偏差为4.3%。     

季铵盐从氰化液中萃取银的宏观动力学研究

本文采用改进的恒界面池(Lewis Cell)对以氢氧化三烷基甲铵—煤油为有机相,含银氰化液为水相的萃取体系进行了萃取反应动力学的研究,实验结果表明,萃取反应过程表现为扩散控制,且扩散阻力主要集中在水相。     

超临界流体重结晶制备HMX微细颗粒和结晶速率的研究

Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that β-HMX microparticle in different average size (2--9.5μm) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.     

PURIFICATION OF BILIRUBIN AND MICRO-PARTICLE FORMATION WITH SUPERCRITICAL FLUID ANTI-SOLVENT PRECIPITATION

1 INTRODUCTIONA supercritical fluid is one existing at temperatures and pressures above its criticalpoint values(T_c,p_c) [1].Supercritical fluid has unconventional thermophysical prop-erties,exhibiting higher density,greater compressibility,lower viscosity between the gasand liquid extremes.Its solute binary diffusion coefficient is considerably higher thanthat in liquids[2-4].Supercritical fluid extraction(SFE)has been suggested as a viablealternative to other separation technologies.     

从季铵盐负载有机相中反萃金银铜

理论分析和实验论证的结果表明,以硫脲作为反萃取剂,在酸性条件下,从季铵盐负载有机相中反萃金、银、铜具有很好的指标。负载有机相经两段共5级的逆流反萃,金、银、铜的反萃率达99.8%以上,并用分段反萃取,可达到金和银、铜的基本分离。用电沉积法提取金属元素后的硫脲盐酸溶液可循环使用。本研究解决了季铵盐作为优良的萃取剂,但难以反萃取的问题。     

超临界CO2-GAS重结晶HMX过程温度对晶体形貌的影响

研究了以丙酮为溶剂的超临界 CO2 - GAS重结晶制细过程温度对 HMX晶型的影响 ,结果表明 :超临界 CO2 - GAS重结晶 HMX过程与常规的重结晶过程相似 ,温度对 HMX晶型起控制作用 ,而对颗粒尺寸影响不大 ;当局部操作温度大于 5 0℃时 ,结晶颗粒中会有α型 HMX生成 ;当整体温度大于 6 0℃时 ,产品中α型 HMX占主要部分。本文就 GAS重结晶过程温度对 HMX晶型影响的机理进行了探讨 ,认为流体压缩和结晶放热引起的局部过热是产生α型 HMX的主要原因     

季铵盐萃取从碱性氰化液中综合提取金,银,铜的半工业试验

对用季铵盐苹取从氰化液中综合提取金、银、铜新工艺进行了小型工业试验,结果表明:金、银、铜的总收率大于99%,高流比立式混和澄清器的混和性能好,分层速度快且易于操作。本工艺具有能耗低、操作成本省及回收率高的特点,并便于大工业连续化生产。