萃余液预处理是避免环境污染、回收有价元素的有效途径，本次工作提出了一种新的萃余液预处理方法——氨水沉淀法，其原理是使用氨水将萃余液中和至pH≈7.5，从而使萃余液中的有价元素Zn、Cu、Pb及Fe形成氢氧化物沉淀析出，而As元素则生成FeAsO₄沉淀。固液分离后，在滤液中加入Na₂S，使其中的微量金属元素发生沉淀，最终实现萃余液中全部有价元素得到有效回收的目标，处理液可作为焙烧氰化工艺中酸浸渣氰化调浆用液。

The extraction raffinate pretreatment can avoid environment pollution.Moreover，it is likewise an effective way of recovering valuable elements.This work proposes a new extraction raffinate pretreatment that is the ammonia precipitation.Principle of the new extraction raffinate pretreatment is to apply ammonium hydroxide to make pH≈7.5 of the raffinate，which can result in the valuable elements（Zn，Cu，Pb，Fe） forming precipitations of hydroxide and then the precipitations separate out quickly，however，the element As forms the FeAsO4 precipitation.After solid-liquid separation，adding Na2S into the filtrate can make some of the trace metal elements begin to precipitate.Finally，the goal that all valuable elements of the extraction raffinate can be recycled effectively comes true.It is found that treatment fluid can be used as a kind of the slurry in roasting cyanide during the process of acid leaching.