废甲醇催化剂综合利用技术进展

甲醇的产能在所有化工产品中仅次于乙烯和合成氨,每年产生的废甲醇催化剂数量巨大。合成甲醇催化剂经历了锌铬高压催化剂、铜基催化剂、合金催化剂及其他非铜基催化剂3个发展阶段,目前在工业中应用的主要为铜基催化剂,此类废催化剂的回收主要围绕Cu和Zn的分离及回收展开。回收工艺可分为酸浸、氨浸和酸浸-电解工艺。废催化剂预处理的关键是在800～1000℃进行焙烧,其目的一是去除有机物,二是脱硫,三是使其中的氧化铝或Cr2O3转化为酸难溶的晶型,四是使金属铜或氧化亚铜转化为氧化铜。预处理后的废催化剂可通过H2SO4酸浸-Zn还原法回收活性ZnO和CuSO4·5H2O,通过H2SO4酸浸-SO32-还原法回收活性ZnO和CuCl,通过HNO3酸浸-Zn还原法制备硝酸盐,通过H2SO4-NHO3联合酸浸法制备胆矾和铝铵矾;通过NH4＋铬合氨浸回收CuCl和活性ZnO,通过NH4＋-NH3复合氨浸回收Cu2O和ZnO;通过H2SO4酸浸-电解回收单质Cu。此外,还可以被制成微肥或作为脱硫剂使用。

Advances in Technology for Recycling Waste Methanol Catalyst

Methanol is the third biggest chemical output in China among all chemical products ,only after ethylene and synthetic ammonia.China produces a large amount of waste methanol catalyst each year.The development of synthetic methanol catalysts experienced three major stages-high-pressure Zn-Cr catalysts,copper-based catalysts,alloy and non-copper-based catalysts.Most catalysts currently used in industrial applications are copper based.The recycling of waste copper-based catalysts mainly involves the separation and recovery of Cu and Zn.There are three main types of waste copper-based catalyst recycling technologies-acid leaching,ammonia leaching and acid leaching-electrolysis.The key to the pretreatment of waste catalysts is roasting them at temperatures between 800-1000℃ to remove organic substance and sulfur,convert the alumina or Cr2O3 in the catalyst to crystal insoluble in acid and to convert metallic copper or cuprous oxide to copper oxide.After pretreatment of the waste catalysts,the H2SO4 leaching-Zn reduction method can be used to recover active ZnO and CuSO4·5H2O;the H2SO4 leaching-SO32-reduction method can be used to recover active ZnO and CuCl;the HNO3 leaching-Zn reduction method can be used to produce nitrate;the H2SO4- NHO3 combination leaching method can be used to make bluestone and ammonium alum;the NH4^＋ chrome complex ammonia leaching method can be used to recover CuCl and active ZnO;the NH4^＋ -NH3 compound ammonia leaching method can be used to recover Cu2O and ZnO;and the H2SO4 acid leaching-electrolysis method can be used to recover elementary Cu.The waste catalysts can also be made into micro-fertilizer or used as a desulfurizing agent.