Mineralization reaction

Yuretich, R.F. and Cerling, T.E. 1983 Hydrogeochemistry of Lake Turkana, Kenya mass balance and mineral reactions in an alkaline lake. Geochimica et Cosmochimica Acta 47 1099-1109. 

The geology not only provides the chemical source for trace-element mobility but it also provides the physical framework for water-flow paths. The structural properties of the rocks, the porosity, permeable fractures, provide for water-mineral reaction and element mobility. The geomorphology contributes to water-table levels, aquifer permeability, surface-water travel times, and time periods for erosion and sediment transport. Examples of... 

Let us consider the problem of finding the stoichiometric coefficients of a mineral reaction, m element concentrations have been measured on n mineral phases of a rock (C/, i= 1,..., m j= 1,..., n) and it is suspected that the phases are not chemically independent. In other words, we can find n numbers Vj (/ = 1,..., n) such that... 

An eigencomponent routine confirms that the matrix ATA has one eigenvalue equal to zero with corresponding eigenvector [0.485, —0.485, +0.2425, —0.485, -0.485]1. It is common practice to use integers as stoichiometric coefficients. This can be achieved by dividing each component by the component of smallest modulus (0.2425), which produces the vector [2, - 2,1, - 2, - 2] corresponding to the mineral reaction... 

Combinations of mineral reactions at lower temperatures and mixing with more dilute fluids are likely to result in the variations in concentration and isotopic composition in many of the continental thermal spring waters but not seen in their marine relatives. The extreme manifestation of this difference may have been generated in the dilute hot spring waters from around Lake Baikal, whose heavy isotopic compositions required extensive re-equilibration at temperatures 100-150°C (Falkner et al. 1997). 

Grustal reservoirs are also variable in Gl-isotope compositions (Figs. 1-6) due to fractionation of the Gl-isotope compositions inherited from their mantle source through fluid-mineral reactions, incorporation of G1 derived from the oceans and fractionation within fluid reservoirs by diffusion (see below). For example, the oceanic crust is enriched in Gl (and pore fluids depleted in Gl) through reaction of seawater with basaltic crust derived from the depleted mantle (Fig. 1 Magenheim et al. 1995). Undoubtedly, future investigations of Gl-isotopes in whole rocks and mineral separates will address the Gl-isotope compositions of these reservoirs and their evolution. 

Ganguly J. and Saxena S. K. (1987). Mixtures and Mineral Reactions. Berlin-Heidelberg-New York Springer-Verlag. 

Thompson A. B. (1976). Mineral reactions in pelitic rocks, II Calculations of some P-T-X (Fe-Mg). phase relations. Amer. Jour. Set, 276 425-444. 

Geospeedometry an extension of geothermometry. In Kinetics and Equilibrium in Mineral Reactions (ed. S.K. Saxena). Springer-Verlag. 

Tabic 6. Identified phosphine mineral reaction products m phosphine- stabilized MS IV bottom ush ... 

Table 7. Identified phosphate mineral reaction products in phosphate-stabilized AfS lV dry scrubber residues... 

The reliable long-term safety assessment of a nuclear waste repository requires the quantification of all processes that may affect the isolation of the nuclear waste from the biosphere. The colloid-mediated radionuclide migration is discussed as a possible pathway for radionuclide release. As soon as groundwater has access to the nuclear waste, a complicated interactive network of physical and chemical reactions is initiated, and may lead to (1) radionuclide mobilization (2) radionuclide retardation by surface sorption and co-precipitation reactions and (3) radionuclide immobilization by mineralization reactions, that is, the inclusion of radionuclides into thermodynamically or kinetically stabilized solid host matrices. 

It is certainly more constant than that of sediments being introduced into the basin. This fact is due to the greater mobility of material in solution which tends to even out local fluctuations in concentration through the action of waves and currents. The sediment is much less subjected to such a mechanical homogenization process and tends, therefore, to attain equilibrium by localized mineral reaction. The type of thermodynamic system operative is most likely to be "open", where each point of sediment has some chemical variables fixed by their concentration in the sediment (inert components due to their low solubility in the solution) and other chemical components, which are soluble, have their concentration in the sediment a function of their activity in the aqueous solution. The bulk composition of the resulting sediment will be largely determined by the composition of the waters in which it is sedimented and the length of time it has reacted with this environment. The composition of the aqueous solution is, of course, determined to a minor extent by these reactions. 

Although gibbsite and kaolinite are important in quantity in some soils and hydrothermal deposits, they have diminishing importance in argillaceous sediments and sedimentary rocks because of their peripheral chemical position. They form the limits of any chemical framework of a clay mineral assemblage and thus rarely become functionally involved in critical clay mineral reactions. This is especially true of systems where most chemical components are inert or extensive variables of the system. More important or characteristic relations will be observed in minerals with more chemical variability which respond readily to minor changes in the thermodynamic parameters of the system in which they are found. However, as the number of chemical components which are intensive variables (perfectly mobile components) increases the aluminous phases become more important because alumina is poorly soluble in aqueous solution, and becomes the inert component and the only extensive variable. 

In zone II, that of normal mixed layered dioctahedral minerals, there are few characteristic mineral reactions. However, the change of the interstratified material as it becomes "allevardite-type" mineral, i.e., showing a discrete super-lattice reflection, is undoubtedly complex. 

Muller T, Baumgartner LP, Foster CT, Vennemann TW (2004) Metastable prograde mineral reactions in contact... 

Hedges, J. I. (1978). The formation of clay mineral reactions of melanoidins. Geochim. Cos-mochim. Acta 42, 69-79. 

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