Circulation of Sodium Sulfate Solution Produced During NiMH Battery Waste Processing

Antti Porvali, Vivek Agarwal, Mari Lundström

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)

Abstract

Hydrometallurgical recovery of rare earth elements (REE) from NiMH battery waste can be performed using sulfuric acid leaching followed by selective precipitation as double salt (REENa(SO4)2·H2O) by adding Na2SO4 as a precipitating agent. The formed double salts can then be further converted with NaOH solution to form REE hydroxides. However, present literature has paid little attention to how to minimize the consumption of reagents in this recovery process. In the current study, a process model was built using HSC Sim software, and metamodeling of the simulated flowsheet was conducted with the design of experiments (DOE), after which the basic functionality of the flowsheet was verified by experimental work, starting from sulfuric acid leaching of spent batteries. As the process is based on chemical circulation internally in the process, the objective was to investigate the accumulation of the elements in solution, specifically Na+, K+, SO4 2− ions and impurities liberated in the NaOH conversion step. It was found out that metamodeling could be utilized in obtaining first estimate of the process behavior, prior to any experiments. Flowsheet functionality with circulated solution was confirmed, obtaining at best 96.9% La recovery.

Original languageEnglish
Pages (from-to)979-991
Number of pages13
JournalMining, Metallurgy and Exploration
Volume36
Issue number5
DOIs
Publication statusPublished - 1 Oct 2019
MoE publication typeA1 Journal article-refereed

Keywords

  • Battery waste
  • Flowsheet metamodeling
  • Hydrometallurgy
  • Rare earths
  • Recycling
  • Response surface methodology

Fingerprint Dive into the research topics of 'Circulation of Sodium Sulfate Solution Produced During NiMH Battery Waste Processing'. Together they form a unique fingerprint.

  • Cite this