Application of the shrinking core model for dissolution of serpentinite in an acid solution

Abstract

Abstract. Serpentinites have the potential to be used as carbo dioxide capture and storage materials. Acid dissolution is the first stage of this process. This study examined how a shrinking core model can be applied to the dissolution of serpentinite in sulphuric acid. The dissolution process was assumed to occur in two stages: an initial step involving the surface dissolution of serpentinite pieces, and a second step involving surface chemical reaction, described by the shrinking core model. The model formulation was completed by relating the dissolution rate of serpentinite to the surface changes.

Investigating the Effect of Reaction Temperature on the Extraction of Calcium from Ironmaking Slag: A Kinetics Study

“…During leaching with (NH4)2SO4 solvent, low recoveries of calcium were observed from analyses. Similar problem has been previously observed with the diffusion-limiting silica (SiO2) layering in silicate minerals such as serpentine [23]. The main reason for the low dissolution of calcium and magnesium from silicate minerals by reaction mechanisms is the increase of particle radius due to increasing silica-rich layer that remains passive during leaching reaction [6].…”

“…The recovery of calcium indicates that the rate-limiting step of dissolution of the dominant mineral in the ironmaking slag (aluminoakermanite) in CH3COOH is most likely due to formation of a passive silica layer. The silica-rich layer remains passive during dissolution of magnesium and calcium from silicate minerals [23].…”

“…Selective flotation of quartz and multi-stage leaching of high-silica minerals that are rich with calcium and magnesium were previously investigated [24]. However, selective separation of free quartz did not eliminate the problem of the formation of gelatinous silica layer during leaching of calcium and magnesium [23].…”

Theoretical evaluation on CO2 removal potential of enhanced weathering based on shrinking core model

“…In experimental and theoretical studies of CDR through EW, surface reaction-controlled shrinking core model (SCM) is often adopted to describe the kinetics of mineral weathering. The solid reactant continues shrinking down as the reaction with the surrounding fluid proceeds [2][3][4][5][6]. The derived mathematical model can be used to fit experimental data for kinetic parameters [4,5] and to theoretically estimate the CDR potential of long-term and large-scale applications [3,6].…”

“…The solid reactant continues shrinking down as the reaction with the surrounding fluid proceeds [2][3][4][5][6]. The derived mathematical model can be used to fit experimental data for kinetic parameters [4,5] and to theoretically estimate the CDR potential of long-term and large-scale applications [3,6].…”