A1 Journal article (refereed), original research

Effective removal of hazardous trace metals from recovery boiler fly ashes


Open Access publication

Publication Details
Authors: Kinnarinen Teemu, Golmaei Mohammad, Jernström Eeva, Häkkinen Antti
Publisher: Elsevier
Publication year: 2018
Language: English
Related Journal or Series Information: Journal of Hazardous Materials
Volume number: 344
Issue number: C
Start page: 770
End page: 777
Number of pages: 8
ISSN: 0304-3894
eISSN: 1873-3336
JUFO-Level of this publication: 2
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe2018101038073

Abstract


The objective of this study is to
introduce a treatment sequence enabling straightforward and effective recovery
of hazardous trace elements from recovery boiler fly ash (RBFA) by a novel
method, and to demonstrate the subsequent removal of Cl and K with the existing
crystallization technology. The treatment sequence comprises two stages:
dissolution of most other RBFA components than the hazardous trace elements in
water in Step 1 of the treatment, and crystallization of the process chemicals in
Step 2. Solid-liquid separation has an important role in the treatment, due to
the need to separate first the small solid residue containing the trace elements,
and to separate the valuable crystals, containing Na and S, from the liquid
rich in Cl and K. According to the results, nearly complete recovery of cadmium,
lead and zinc can be reached even without pH adjustment. Some other metals,
such as Mg and Mn, are removed together with the hazardous metals. Regarding
the removal of Cl and K from the process, in this non-optimized case the
removal efficiency was satisfactory: 60-70 % for K when 80 % of sodium was
recovered, and close to 70 % for Cl when 80 % of sulfate was recovered.


Last updated on 2019-29-03 at 08:48