废钴钼系催化剂中金属的全回收新工艺研究

A new process for complete recycling of metals from spent Co/Mo/γ-Al_2O_3 catalyst

开发了一种用于废Co/Mo/γ-Al2O3催化剂的金属全回收工艺。首先将催化剂在通空气的情况下进行氧化燃烧以除去碳和硫。焙烧后样品经浓氨水多次浸取,得到的溶液部分先用锌置换络合物中的少量钴,之后加硝酸回收MoO3;氨浸后的滤渣用硫酸溶解,加硫酸铵分离出氨明矾,以去掉大部分铝;所得少量浓缩液去掉铁等杂质之后,加过量氨使钴形成络合物,再用锌粉置换出金属钴粉。Mo、Al、Co的回收率分别大于90%、85%和90%。

A complete metals recovery process has been developed for spent Co/Mo/γ-Al_2O_3 catalyst.This process starts with roasting the catalyst in air to eliminate carbon and sulfur.After the caustic roasting,the residue is leached by concentrated ammonia to obtain a solution containing mainly molybdenum,and a solid containing essentially alumina and cobalt.Then the solution is treated with nitric acid and concentrated ammonia to obtain highly pure ammonium molybdate.The solid is continually dissolved by sulphuric acid.Aluminium can be directly crystallized with ammonium sulfate to form ammonium alum.Cobalt can be converted into complex ion by excess ammonia and then recovered as highly pure metal cobalt powder by replacing with zinc powder.The recovery rate for molybdenum,aluminum and alcobalt can be higher than 90%,85% and 90%,respectively.