Speaker
Description
This study explores the valorization of a water-granulated platinum slag (GPS) as both a fine aggregate replacement and a supplementary cementitious material (SCM) in mortar formulations. The slag, a byproduct of platinum smelting operations, contains high amorphous content and elevated MgO and Al₂O₃ levels—making it a potential contributor to cement chemistry when properly processed.
The GPS was tested in two ways. First, as a sand substitute (0-100%) sand replacement, and second, ground to make ground granulated platinum slag (GGPS) as a 30% Ordinary Portland Cement (OPC) replacement. Three mortar systems were developed: (i) OPC-only, (ii) OPC with 30% fly ash, and (iii) OPC with 30% GGPS. Mixes were evaluated for workability, compressive strength, alkali-silica reactivity (ASR), and autoclave expansion.
ASR testing showed that GPS used as sand replacement resulted in excessive expansion (>0.2%), but this was effectively mitigated with the addition of fly ash, enabling up to 100% sand replacement without compromising performance. Autoclave expansion remained within acceptable limits in all cases, indicating mineralogical stability despite high MgO content. The GGPS exhibited a Blaine fineness of 441 m²/kg and was found to be chemically active, with favorable ASR suppression and strength comparable to control mixes.
These results support the use of alumina-bearing GPS and GGPS as promising, industrially sourced SCMs that can help cement manufacturers reach their sustainability and decarbonization goals. Ongoing work is focused on optimizing hybrid binder systems (e.g., fly ash + GGPS) for improved performance in durable and resource-efficient calcium aluminate-based systems.
Affiliations
1Insight R&D, 376 Mill Street, Unit #7, Dundas, Ontario, Canada, L9H 2M1, santiago@insight-rnd.com, kelly@insight-rnd.com
| Keywords | Calcium aluminates, supplementary cementitious materials (SCM), platinum slag, alkali-silica reactivity (ASR) mitigation, sustainable construction |
|---|