Experimental study of dissolution rates of multi-oxide silicates in water up to 400 ℃
Dissolution rates of silicate minerals in water were measured using a flow-through experimental reactor in the temperature range from 25 to 400 ℃ and at 22 MPa. Different metals possess generally nonstoichiometric release rate. Results show that metals (Na, Ca, Mg, Fe, Al) dissolve faster than Si at 25 to 300 ℃,but slower from 300 to 400 ℃. The dissolution stoichiometry becomes nearly congruent at 200℃ to 300℃ (e.g.actinolite, albite).Experiments prove that the logarithm of the far from equilibrium dissolution rates (release rates) of multi-oxide silicate mineral will be linearly related to the logarithm of the activity of dissolved Mk.Usually, its far from equilibrium dissolution rates at all pH of the solution would depend on both pH and aqueous MkZk activity. Zk is the valence of the metal Mk in the mineral. MkZk refers to Ca2+, Mg2+ Al3+ etc.
R.H.Zhang X.T.Zhang S.M.Hu
Laboratory of Geochemical Kinetics, Institute of Mineral Resources, Chinese Academy of Geological Sciences,Beijing, China
国际会议
第十二届水-岩相互作用国际研讨会(P0roceedings of the 12th International Symposium on Water-Rock Interaction)
昆明
英文
403-406
2007-07-31（万方平台首次上网日期，不代表论文的发表时间）