Magnesite dissolution rate

Figure 2.10. Dissolution rates as a function of pH for aragonite, calcite, witherite, dolomite, and magnesite. (After Chou et al., 1989.)...

The rates of dissolution of various carbonates were studied in [200], The kinetics of magnesite dissolution was studied in [201] and that of dolomite dissolution in [202,203],... 

Nonetheless, the general understanding of magnesium and calcium carbonation reactions has improved significantly (see also the studies by Hanchen et al. [107-110] on the relative importance of process parameters such as temperature, C02 pressure and particle size distribution). Studies involving a three-step process of olivine carbonation, involving (i) dissolution of olivine (ii) precipitation of magnesite and (iii) precipitation of silica in an aqueous solution, were recently reported from Norway [69], where the process proceeds without chemical additives at 10-15 MPa and 403-523 K. No reaction rates were reported, however. 

Magnesite is the most common magnesium carbonate mineral in geological environments. In spite of this fact, it is rarely observed precipitating from natural waters. Further, its low-temperature solubility has been extremely difficult to measure because of its very slow rate of dissolution in the laboratory (cf. Langmuir 1965). The - log of 4.9 for magnesite given in Table 6.1 is consistent... 

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