Hydrometallurgical recovery of zinc from filter-pressed wastewater treatment precipitates and nanofiltration treatment

Helmholtz-Zentrum Dresden-Rossendorf HZDR (Forschungsstelle Leipzig)

01328 Dresden

Bewerbungsfrist nicht angegeben

Overview

The old smelting activities in different regions in Germany generated large quantities of metallurgical and mining residues containing significant concentrations of valuable metals.
In recent days, the contaminated surface water from these residues is treated at a wastewater treatment plant by lime precipitation.
The generated sludge has been dewatered using a chamber filter press and is currently disposed of as a landfill.
Recent investigations have demonstrated that these wastewater treatment precipitates contain a considerable of valuable metals, and it represents a promising secondary raw material for the recovery of valuable metals, especially zinc.
The objective of the proposed master thesis is to develop a hydrometallurgical process for the selective recovery of zinc from the wastewater treatment precipitates.
The work will investigate selective acid leaching conditions to dissolve zinc while minimizing the dissolution of calcium, magnesium and silicon.
After purification, high-purity metallic zinc will be recovered by electrowinning.
The calcium-rich leaching residue will be characterized thoroughly in order to evaluate its potential for industrial applications.
The process wastewater generated during the metal recovery process will be treated with membrane purification studies, contributing towards a circular economy approach.

Develop a hydrometallurgical process for the selective recovery of zinc from wastewater treatment precipitates.
Investigate selective acid leaching conditions to dissolve zinc while minimizing dissolution of calcium, magnesium and silicon.
Purify the pregnant leach solution through selective precipitation of metals other than zinc by pH adjustment.
After purification, recover high-purity metallic zinc by electrowinning.
Characterize the calcium-rich leaching residue to evaluate potential industrial applications.
Treat the process wastewater generated during the metal recovery process with membrane purification studies.

Bachelor's degree in Chemistry, Chemical Engineering, Environmental Engineering or related field
Knowledge of hydrometallurgical methods such as Leaching, precipitation, solvent extraction, and membrane technologies
Knowledge of analytical techniques such as ICP-OES, AAS, MS or similar for metal concentration analysis
Good oral and written communication skills in English
Ability to work independently and systematically

Department: Hydrometallurgy
Contact: Hossain, MD Naziat, Kantamani, Rama Swami, Dr. Kelly, Norman, Recksiek, Volker