Metals (Dec 2015)

Direct Aqueous Mineral Carbonation of Waste Slate Using Ammonium Salt Solutions

  • Hwanju Jo,
  • Ho Young Jo,
  • Sunwon Rha,
  • Pyeong-Koo Lee

DOI
https://doi.org/10.3390/met5042413
Journal volume & issue
Vol. 5, no. 4
pp. 2413 – 2427

Abstract

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The carbonation of asbestos-containing waste slate using a direct aqueous mineral carbonation method was evaluated. Leaching and carbonation tests were conducted on asbestos-containing waste slate using ammonium salt (CH3COONH4, NH4NO3, and NH4HSO4) solutions at various concentrations. The CH3COONH4 solution had the highest Ca-leaching efficiency (17%–35%) and the NH4HSO4 solution had the highest Mg-leaching efficiency (7%–24%) at various solid dosages and solvent concentrations. The CaCO3 content of the reacted materials based on thermogravimetric analysis (TGA) was approximately 10%–17% higher than that of the as-received material for the 1 M CH3COONH4 and the 1 M NH4HSO4 solutions. The carbonates were precipitated on the surface of chrysotile, which was contained in the waste slate reacted with CO2. These results imply that CO2 can be sequestered by a direct aqueous mineral carbonation using waste slate.

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