Mineral formations

The seventh element in order of abundance in the Earth s crust is potassium - about the same as sfjdium with similar properties. While sodium is readily available from the ocean, potassium is found and extracted from many mineral formations. About 90 percent of the potassium that is extracted goes to the production of fertilizers. Other purposes for it are ceramics and fire extinguishers for which potassium bicarbonate is better than sodium bicarbonate. 

Hallberg, R. O. (1972). Sedimentary sulfide mineral formation - an energy circuit system approach. Mineral. Deposit. 7,189-201. 

Michalopoulos, P. and Aller, R. C. (1995). Rapid clay mineral formation in Amazon Delta sediments reverse weathering and oceanic elemental cycles. Science 270, 614-617. 

Present account provides a preliminary knowledge of the processes leading to mineral formation. The coverage is amply illustrated. The account has also made references to re-... 

Another specific and important aspect to consider is the possibility that an environmentally heterogeneous photocatalyst can lead to the undesirable formation of reaction intermediates which are more toxic than the starting reagents. For instance, the Ti02-based photodegradation of ethanol, a relatively innocuous air pollutant, occurs through its transformation into the more toxic acetaldehyde. Condensation reactions can also lead to the formation of traces of methyl formate, ethyl formate, or methyl acetate. Catalyst design is therefore important to increase the overall oxidation rate to ensure complete mineralization (formation of C02 and H20). 

The nanostructured fossils seem now to be less likely from Martian nanobacteria and probably are artefacts of the mineral formation process. Ironically, however, the discovery of the nanofossils may have been responsible for the massive interest in astrobiology, causing NASA to found the subject almost overnight. 

A substantial removal of metals during the spike event followed by a release over time from the ABRs is seen, it may be inferred that filtration, adsorption and subsequent mineral formation contribute to metal removal. Although adsorption plays a part in the removal of metals, sites on the organic substrate are likely to be quickly saturated. 

Edwards, R. Gillard, R.D., Williams, P.A. and Pollard, A.M. (1992). Studies of secondary mineral formation in the PbO-H20-HCl system. Mineralogical Magazine 56 51-63. 

The Ostwald Step Rule, or the rule of stages postulates that the precipitate with the highest solubility, i.e., the least stable solid phase will form first in a consecutive precipitation reaction. This rule is very well documented mineral formation via precursors and intermediates can be explained by the kinetics of the nucleation process. The precipitation sequence results because the nucleation of a more soluble... 

The anomalous Na decrease with depth in Figure 4 illustrates a problem with ion team profiling in that some light ions, including Na, are mobile under the beam and can be stripped from the surface or embedded deeper in the matrix. K ions do not appear to be susceptible to this phenomenon and heavier elements such as Rb, Cs and Sr would be expected to be even less affected. Profiles of Si and Al, although not shown in Figure 4, were essentially constant with depth documenting the lack of secondary mineral formation on the surfaces of the obsidian and feldspar. 

Selected values of (1000 A)1/2 for quartz = mineral lsO, and pyrite = mineral 34S equilibria are found in Table 9.2. In other cases, especially at lower temperature, the temperature dependence of IE s on mineral formation may be more complicated and require empirical fits of the form, in a = Ci/T + C2/T2 or in a = Co + Ci/T + C2/T2, the C s are empirical least squares fitting parameters. 

Table 3. Summary of Fe isotope fractionations during biogenic mineral formation.

The chemical weathering of crustal rock was discussed in Chapter 14 from the perspective of clay mineral formation. It was shown that acid attack of igneous silicates produces dissolved ions and a weathered solid residue, called a clay mineral. Examples of these weathering reactions were shown in Table 14.1 using CO2 + H2O as the acid (carbonic acid). Other minerals that undergo terrestrial weathering include the evaporites, biogenic carbonates, and sulfides. Their contributions to the major ion content of river water are shown in Table 21.1. 

Korzhinskii, D.S. 1963. Correlation between activity of oxygen, oxidity and reduction potential in endogenic mineral formation. Izvestiya of Academy of Sciences of USSR. Geological seria. No. 3. 54-61. (In Russian)... 

In conclusion, the pedosphere is an environment of active mineral formation and transformation and exhibits a large variation in formation parameters in space and time over a range of scales. It openly and permanently communicates with neigh-... 

De Putter, T., Andre, L., Bernard, A., Dupuis, C., Jedwab, J., Nicaise, D. Perruchot, A. 2002. Trace element (Th, U, Pb, REE) behaviour in a cryptokarstic halloysite and kaolinite deposit from Southern Belgium importance of accessory mineral formation for radioactive pollutant trapping. Applied Geochemistry, 17, 1313-1328. 

Donahoe, R. J. (2004). Secondary Mineral Formation in Coal Combustion Byproduct Disposal Facilities Implications for Trace Element Sequestration. In Giere, R. Stille, P. (eds) Energy, Waste, and the Environment a Geochemical Perspective. Geological Society, London, Special Publications, 236, 641-658. 

Dilaktorsky, N. L. Galibina, E. A. 1955. The processes of mineral formation during the heating of oil shale ash and hardening of hydrate products of burning. In Oil Shale Ash Materials in Building. Estonian Academy, Tallinn, 31—46 (in Russian). 

Secondary mineral formation in coal combustion byproduct disposal facilities implications for trace element sequestration... 

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