AUTHOR=Suiyi Zhu , Jian Wang , Yuhong Huang , Ying Wang , Yuxin Zhang , Jiabao Qin , Jiancong Liu , Jinlu Yao , Meichun Ji 

TITLE=Perspective on pH adjustment in hydrometallurgical recycling of valuable metals from waste

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1177173

DOI=10.3389/fchem.2023.1177173

ISSN=2296-2646

ABSTRACT=pH adjustment was considered as a simple step in hydrometallurgy process, but its complicated operation was ignored in the past. In some industrial applications, the leachate pH was slowly adjusted by diluted alkaline solution, with the defects of doubling the leachate volume and causing the droplet hydrolysis/coagulation. Up to date, the promising routes were advanced for rapid pH adjustment, especially in the sealed high- temperature/pressure vessel. New routes emerged in the some redox/decomposition reactions of nitrate/urea, and organics. Such reactions were stable at room temperature, but started spontaneously at high temperature, to generate/consume free H+. This induced the perspective of pH adjustment via a rapid and homogeneous way.