Optimization of Metal Recovery from MSWI Fly Ash by Acid Leaching: Findings from Laboratory- and Industrial-Scale Experiments

Weibel, Gisela; Zappatini, Anna; Wolffers, Mirjam; Ringmann, Stefan (2021). Optimization of Metal Recovery from MSWI Fly Ash by Acid Leaching: Findings from Laboratory- and Industrial-Scale Experiments. Processes, 9(2), p. 352. MDPI 10.3390/pr9020352

[img]
Preview
Text
processes-09-00352-v2.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (2MB) | Preview

A major part of Swiss fly ashes (FA) from municipal solid waste incineration (MSWI) are treated with the acid fly ash leaching process (FLUWA) in order to recover heavy metals prior to deposition. The FLUWA process uses scrub water from wet flue gas cleaning to leach heavy metals from FA. The leaching efficiency is strongly dependent on the leaching conditions (e.g., pH, Eh, L/S-ratio). This case study presents the optimization of the FLUWA process at the MSWI plant Linth, Switzerland, through determination of ideal process parameters for optimal metal recovery. By means of laboratory- and industrial-scale experiments, the process was adjusted towards a more efficient leaching of Zn, Pb, Cu, and Cd. This included the use of an oxidizing agent (hydrogen peroxide). Laboratory experiments proved to be a powerful tool for simulating process optimizations at industrial scale. An ideal leaching pH of 3.8 was determined and it was observed that the process stability is significantly influenced by the L/S-ratio applied to the leaching process. In the course of the study, the recovery could be improved to 67% Zn, 66% Pb, 30% Cu, and 91% Cd. It can be concluded that for optimal metal recovery the process has to be individually adjusted to the composition of the processed FA and scrub water of each specific FLUWA process.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences > Mineralogy
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Weibel, Gisela; Zappatini, Anna and Wolffers, Mirjam

Subjects:

500 Science > 550 Earth sciences & geology
600 Technology > 620 Engineering

ISSN:

2227-9717

Publisher:

MDPI

Funders:

[UNSPECIFIED] KVA Linth ; [UNSPECIFIED] Schweizerisches Bundesamt für Umwelt (BAFU) ; [UNSPECIFIED] Verband der Betreiber Schweizerischer Abfallverwertungsanlagen (VBSA)

Language:

English

Submitter:

Anna Zappatini

Date Deposited:

23 Feb 2021 14:58

Last Modified:

23 Feb 2021 14:58

Publisher DOI:

10.3390/pr9020352

BORIS DOI:

10.48350/152520

URI:

https://boris.unibe.ch/id/eprint/152520

Actions (login required)

Edit item Edit item
Provide Feedback