Addendum to "Process development for elemental recovery from PGM tailings by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent" [Waste Manage. 50 (2016) 334–345]. (August 2017)

• Record Type: Journal Article
• Authors: Mohamed, Sameera; van der Merwe, Elizabet M.; Altermann, Wladyslaw; Doucet, Frédéric J.
• Is Part Of: Waste management. Volume 66(2017)
• Page Start: 222
• Page End: 224
• Publication Date: 2017-08
• Subjects: PGM tailings -- Ammonium sulphate -- Metal recovery and extraction -- Thermochemical treatment -- Solid-solid reaction; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2017.04.009
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: This contribution amends an oversight in Mohamed et al. (2016) with a new control. The control was untreated tailings leached in 0.63 M HNO3 at 95 °C for 6 h. Extraction efficiencies amount to 27% for Al, 69% for Ca and 3% for Fe. 0% Cr and 9% Mg were co-extracted. Extracted Si was identical for control and treatment (with thermochemical step). The conclusion of the previous paper (Mohamed et al., 2016) withstands. Abstract: In a recent paper, a promising two-stage process for the extraction of major elements from Platinum Group Metals (PGM) was presented (Mohamed et al., 2016). This process involved solid-solid thermochemical treatment of tailings with ammonium sulphate (stage one), followed by an optimised acid dissolution step (stage two). The inclusion of a control experiment for the optimal dissolution procedure was however overlooked. The new set of data delivered by the control experiment reveals that (i) most of the silicon and calcium are extracted via the acid leaching step, (ii) aluminium and magnesium are extracted at each stage of the process, and (iii) the thermochemical step is the main contributor to chromium and iron extraction. The conclusion of the previous paper (Mohamed et al., 2016), whereby thermochemical treatment with ammonium sulphate represents a promising technology for extracting valuable elements from South African PGM tailings, withstands.