Abstract

Electric furnace ferronickel slag (EFS) is a typical magnesium-rich industrial by-product discharged from the manufacture of nickel and iron-nickel alloys. The approach to use it as the raw material for the preparation of magnesium phosphate cement (MPC) has potential and proves effec-tive. In this study, three different phosphorus sources (PS) including phosphoric acid (H3 PO4, PA), sodium dihydrogen phosphate (NaH2 PO4, SDP) and potassium dihydrogen phosphate (KH2 PO4, PDP) were used to react with EFS to prepare the EFS-based MPC (EMPC), and the effects of raw material mass ratio (EFS/PA, EFS/SDP, EFS/PDP) on the compressive strength, early hydration temperature and microstructure of EMPC pastes were investigated. Results showed that the compressive strength of EMPC paste is significantly impacted by the type of phosphorus source and the raw materials mass ratio. When the EFS/PDP ratio is 4.0, the compressive strength of the MPC paste reaches up to 18.8, 22.8 and 27.5 MPa at 3, 7 and 28 d, respectively. Cattiite (Mg3 (PO4 )2·22H2 O), K-struvite (KMgPO4·6H2 O) and/or Na-struvite (NaMgPO4·6H2 O) were identified as the main hydration prod-ucts of EMPC. The development of EMPC mainly involves the dissolution of a phosphorus source, MgO and Mg2 SiO4, formation of hydration product as binder, and combination of the unreacted raw materials together by binders to build a compact form.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

National Natural Science Foundation of China, Grant 21866018

Keywords and Phrases

Electric furnace ferronickel slag; Hydration product; Magnesium phosphate cement; Phosphorus source

International Standard Serial Number (ISSN)

1996-1944

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2023 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Mar 2022

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