Dissolution of Magnesium from Serpentine Mineral in Sulfuric Acid Solution

Abstract

As the volume of CO 2 , one of greenhouse gases linked to global warming, in the atmosphere increases, there has been an increasing interest in CO 2 sequestration. Aqueous carbonation, which involves the extraction of Mg from serpentine minerals and the subsequent carbonation reaction with CO 2 to form the geologically stable mineral MgCO 3 , has been proposed as a promising CO 2 sequestration technology. This study investigates the dissolution of Mg from serpentine mineral in H 2 SO 4 solution. The study is part of a major research project aimed at developing an effective CO 2 sequestration technology using the serpentine mineral which is readily available in Korea. Complete dissolution of Mg from natural serpentine was achieved in 30 min at a temperature of 90 C under 0.5 M H 2 SO 4 . The rate of dissolution of Mg was independent of the agitation speed at speeds above 300 rpm. The fraction of Mg dissolved from milled serpentine was found to be a little higher than that from natural serpentine up to 70 C in 0.5 M H 2 SO 4 . The Jander equation was used to explain the dissolution rate data. The rate of Mg dissolution seemed to be limited by diffusion through the thin channels formed between the silica layers in the serpentine particles.

Serpentinites: Mineral Structure, Properties and Technological Applications

“…Serpentinite contains 32-38% MgO and 35-40% SiO 2 and can be a source for these oxides. 31 Pure magnesium compounds can be produced from serpentinite through acid leaching (equation 3).…”

Optimization of leaching conditions for extraction of magnesium from a chromite beneficiation plant tailing predominantly containing lizardite

“…Serpentine is a 1:1 hydrous magnesium iron phyllosilicate mineral consisting of tetrahedral silicate (SiO 2 ) and octahedral brucite (MgOH 2 ) layers (Park and Fan, 2004). Leaching of serpentine minerals results in dissolution of the brucite layers and remaining amorphous silicate layers (Yoo et al, 2009). It is expected that brucite dissolution rate increases with the increasing of temperature, acid concentration, and time but decreases with increasing of solid ratio.…”

CO2 Absorption and Magnesium Carbonate Precipitation in MgCl2–NH3–NH4Cl Solutions: Implications for Carbon Capture and Storage

“…Among the many materials tested, magnesium-rich materials are thought to be good candidates for carbonation due to their natural abundance [14] and relatively higher unit mass binding efficiency (e.g., as compared to calcium). For example, physical activation (grinding [15][16][17] or heating [18,19]), chemical leaching (acid [20][21][22], recyclable ammonium salt [23,24] or non-acidic ionic solutions [25]), bioleaching [26,27] were applied to Mg rich minerals to dissolve and concentrate Mg. However, the other CO 2 absorption and carbonate precipitation steps have been less explored.…”

“…In essence, the diffusion film on the gas side and the solution side determine the efficiency of mass transfer. In this framework, the rate of CO 2 absorption (ϕ CO 2 ) can be written as: (20) and…”