为实现铂炭催化剂样品中高含量铂的低成本、准确测定,采用氯铂酸铵重量法测定主量铂,电感耦合等离子体原子发射光谱法(ICP-AES)测定微量铂,并以二者之和计算样品中铂的含量。称取0.200 0 g样品,加入10 m L盐酸和5 m L硝酸,于200℃加热10...为实现铂炭催化剂样品中高含量铂的低成本、准确测定,采用氯铂酸铵重量法测定主量铂,电感耦合等离子体原子发射光谱法(ICP-AES)测定微量铂,并以二者之和计算样品中铂的含量。称取0.200 0 g样品,加入10 m L盐酸和5 m L硝酸,于200℃加热10 min后加入5 m L高氯酸,于280℃加热至样品完全溶解。加入5 m L盐酸,于200℃蒸发至溶液近干,重复该步骤2次。收集残余物,加入2 m L盐酸和8 m L水,再边搅拌边缓慢加入(85±5)℃的饱和氯化铵溶液50 m L,于150℃蒸发至溶液近干。冷却,边搅拌边加水,使残留的氯化铵晶体完全溶解,静置12 h。用定量滤纸过滤,洗涤沉淀,将滤纸包裹着的沉淀转移至已恒重的瓷坩埚中,用电炉在程序升温条件下加热至滤纸完全烘干并灰化,当白色烟雾消失时停止加热,取下瓷坩埚,于900℃灼烧2 h,冷却后称重,计算主量铂的质量分数。将滤液于180℃加热浓缩,待体积变小至有氯化铵晶体析出时,缓慢加入20 m L硝酸,于180℃继续加热以分解氯化铵,重复该步骤直至无氯化铵晶体析出,于180℃加热至溶液剩余约2 m L,加入10 m L盐酸加热至沸,冷却后用水稀释至100 m L,采用ICP-AES在分析谱线214.423 nm下测定微量铂。结果显示,ICP-AES所得铂的质量浓度在20.00 mg·L^(-1)以内和谱线强度呈线性关系,检出限(3s)为0.013 8 mg·L^(-1);实际样品的10次重复测定的相对标准偏差为0.17%,标准加入法所得的铂的回收率为98.9%~103%。展开更多
Auto-catalysts were the largest consumers of platinum group metals and the most important secondary resources, recovery of PGMs from spent auto-catalysts by leaching with various acidities were investigated. The leach...Auto-catalysts were the largest consumers of platinum group metals and the most important secondary resources, recovery of PGMs from spent auto-catalysts by leaching with various acidities were investigated. The leaching thermodynamics of PGMs at 363 K was first discussed. At 363 K the higher the acidities of HCl, the higher the leaching recoveries of PGMs, and the sequence of leaching recovery was Pd>Pt>Rh. When H2SO4 used alone, the leaching recoveries of PGMs was low, when the acidity of H2SO4 increasing, the leaching recovery of Rh kept stable.展开更多
文摘为实现铂炭催化剂样品中高含量铂的低成本、准确测定,采用氯铂酸铵重量法测定主量铂,电感耦合等离子体原子发射光谱法(ICP-AES)测定微量铂,并以二者之和计算样品中铂的含量。称取0.200 0 g样品,加入10 m L盐酸和5 m L硝酸,于200℃加热10 min后加入5 m L高氯酸,于280℃加热至样品完全溶解。加入5 m L盐酸,于200℃蒸发至溶液近干,重复该步骤2次。收集残余物,加入2 m L盐酸和8 m L水,再边搅拌边缓慢加入(85±5)℃的饱和氯化铵溶液50 m L,于150℃蒸发至溶液近干。冷却,边搅拌边加水,使残留的氯化铵晶体完全溶解,静置12 h。用定量滤纸过滤,洗涤沉淀,将滤纸包裹着的沉淀转移至已恒重的瓷坩埚中,用电炉在程序升温条件下加热至滤纸完全烘干并灰化,当白色烟雾消失时停止加热,取下瓷坩埚,于900℃灼烧2 h,冷却后称重,计算主量铂的质量分数。将滤液于180℃加热浓缩,待体积变小至有氯化铵晶体析出时,缓慢加入20 m L硝酸,于180℃继续加热以分解氯化铵,重复该步骤直至无氯化铵晶体析出,于180℃加热至溶液剩余约2 m L,加入10 m L盐酸加热至沸,冷却后用水稀释至100 m L,采用ICP-AES在分析谱线214.423 nm下测定微量铂。结果显示,ICP-AES所得铂的质量浓度在20.00 mg·L^(-1)以内和谱线强度呈线性关系,检出限(3s)为0.013 8 mg·L^(-1);实际样品的10次重复测定的相对标准偏差为0.17%,标准加入法所得的铂的回收率为98.9%~103%。
文摘Auto-catalysts were the largest consumers of platinum group metals and the most important secondary resources, recovery of PGMs from spent auto-catalysts by leaching with various acidities were investigated. The leaching thermodynamics of PGMs at 363 K was first discussed. At 363 K the higher the acidities of HCl, the higher the leaching recoveries of PGMs, and the sequence of leaching recovery was Pd>Pt>Rh. When H2SO4 used alone, the leaching recoveries of PGMs was low, when the acidity of H2SO4 increasing, the leaching recovery of Rh kept stable.
