Experimental deployment of microbial mineral carbonation at an asbestos mine: Potential applications to carbon storage and tailings stabilization

Jenine McCutcheon, Connor C. Turvey, Siobhan A. Wilson, Jessica L. Hamilton, Gordon Southam

Research output: Contribution to journalArticleResearchpeer-review

13 Citations (Scopus)

Abstract

A microbial mineral carbonation trial was conducted at the Woodsreef Asbestos Mine (NSW, Australia) to test cyanobacteria-accelerated Mg-carbonate mineral precipitation in mine tailings. The experiment aimed to produce a carbonate crust on the tailings pile surface using atmospheric carbon dioxide and magnesium from serpentine minerals (asbestiform chrysotile; Mg3Si2O5(OH)4) and brucite [Mg(OH)2]. The crust would serve two purposes: Sequestering carbon and stabilizing the hazardous tailings. Two plots (0.5 m3) on the tailings pile were treated with sulfuric acid prior to one plot being inoculated with a cyanobacteria-dominated consortium enriched from the mine pit lakes. After 11 weeks, mineral abundances in control and treated tailings were quantified by Rietveld refinement of powder X-ray diffraction data. Both treated plots possessed pyroaurite [Mg6Fe2(CO3)(OH)16•4H2O] at 2 cm depth, made visible by its orange-red color. The inoculated plot exhibited an increase in the hydromagnesite [Mg5(CO3)4(OH)2•4H2O] content from 2-4 cm depth. The degree of mineral carbonation was limited compared to previous experiments, revealing the difficulty of transitioning from laboratory conditions to mine-site mineral carbonation. Water and carbon availability were limiting factors for mineral carbonation. Overcoming these limitations and enhancing microbial activity could make microbial carbonation a viable strategy for carbon sequestration in mine tailings.

Original languageEnglish
Article number191
Number of pages18
JournalMinerals
Volume7
Issue number10
DOIs
Publication statusPublished - 12 Oct 2017

Keywords

  • Carbonate minerals
  • Cement precipitation
  • Chrysotile asbestos
  • CO storage
  • Cyanobacteria
  • Microbial carbonation
  • Mine tailings
  • Mineral carbonation

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