Geochemical modelling of diethylenetriamine in tailings management areas. (January 2022)

• Record Type: Journal Article
• Authors: Tian, Xinyi Wendy; Furnell, Erin; Bobicki, Erin R.
• Is Part Of: Minerals engineering. Volume 176(2022)
• Publication Date: 2022-01
• Subjects: Geochemical modelling -- OLI -- Pyrrhotite tailings -- Diethylenetriamine; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2021.107334
• Languages: English
• ISSNs: 0892-6875

Abstract

Highlights: Geochemical modelling used to predict interactions of metal ions with DETA. Cu-DETA and Ni-DETA complexes are stable and soluble over a wide pH range. Cu-DETA complexes more stable than Ni-DETA complexes, especially at alkaline pH. Lime treatment insufficient to remove Cu-DETA and Ni-DETA complexes from effluent. Sulphide precipitation is promising to precipitate Cu-DETA and Ni-DETA complexes. Abstract: Diethylenetriamine (DETA) is an effective mineral processing reagent for the depression of pyrrhotite in the flotation of Cu-Ni ores. DETA is a chelating agent and forms stable complexes with Cu and Ni ions that cannot be removed with traditional mining effluent treatment. The recalcitrance of metal-DETA complexes to wastewater treatment can result in effluent quality that does not meet regulatory requirements. To better understand the behaviour of DETA in the tailings and effluent environments, the interaction of DETA with metal species was investigated via geochemical modelling using OLI Studio. The concentrations and specific species of metal-DETA complexes were modelled with varying pH levels and metal-to-DETA ratios. The results suggest that DETA is most likely to chelate with Cu 2+, followed by Ni 2+ . Very little Fe 2+ is expected to combine with DETA, especially when Ni 2+ and Cu 2+ are present. Moreover, both Cu-DETA and Ni-DETA chelates are stable over the pH range of 4 to 14. The modelling results agree with what has been observed in mineral processing operations. Sulphide precipitation was also investigated as a possible treatment technique and appears promising for the removal of Cu 2+ and Ni 2+ from DETA-containing effluent.