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On the Reactivity of Various Silicate Minerals toward Acids

1961; Oxford University Press; Volume: 34; Issue: 2 Linguagem: Inglês

10.1246/bcsj.34.214

1348-0634

Hanzo Mase,

Thermal and Kinetic Analysis

Abstract In this paper, the author proposed a classified table of metals contained in silicate minerals, and the qualitative and conventional rules in which it appeared possible to predict the reactivity of all the known silicate minerals toward ordinary mineral acids. In the classification and rules, ionic potential, Goldschmidt’s polarizing power, and field strength of the metals in the silicate minerals play important roles. The rules are summarized as follows: 1) the silicate minerals—especially, the neso- and sorosilicate ones composed of the comparative simple ionic crystal lattices—containing the less electropositive metals (e.g., Ti, Be, Al, Cr, V(III), Fe(III), Mn(III), Zr, etc.) are generally unattacked by acids; 2) in the ino-, phyllo-, and tecto-silicate minerals, which contain various polymerized and giant silicate ions, their structures exert a favorable influence upon their reactivity toward acids. Thus, in these minerals, it is necessary for us to take their structural effects into consideration, besides the above rule 1) ; and 3) the bonding energies of silicate minerals are closely related to their reactivity. In general, the neso-, soro-, ino-, and phyllo-silicate minerals of which bonding energies are less than about 30500 kcal. and the tectosilicate ones of which the energies are less than about 33500 kcal. seem to be decomposed by acids.