Fluid activities mineral interactions

Figure 12.3 Simplified model for the various processes governing the Cu and Zn isotopic composition collected in the Talbot area of Canada [33], The ore zone is redox-active, with interactions between microbes and fluids on the sulfide ores mobilizing Cu and Zn as aqueous and gaseous complexes into the overlying sandstone and carbonate, which are about 100 m thick in total. Migration of these components occurs through micro- and macrofractures and then they are trapped in the near-surface environment on clay minerals in the till or incorporated into the biosphere, including trees, moss, and organic matter in the soils.

The second example concerns the surface heterogeneity of clay minerals. Important problems, such as limited yield of oil recovery arising during oil exploitation, involve interaction of pore filling fluids with the minerals that form the reservoir walls. The clay minerals, due to their relatively high specific surface area and electrical charge density, are the most active for the retention of oil. Illites and kaolinites are the clay minerals that are most frequently found and their wettability properties are believed to be in relation to the heavy oil ends retention process. 

The rate of flow between fluids in fractures and in the rock matrix is a crucial factor for transport and reaction in fractures. For consistency with the formulation for flow between fractures and matrix used in the Yucca Mountain Project, the reactive surface area for minerals in unsaturated fractures has been related to the fracture-matrix interaction area based on a modified form of the Active Fracture Model (Liu et al., 1998 Sonnenthal el al., 2003). In this way, the wetted surface area for mineral-water reactions is consistent with that for flow and diffusion. 

Dissolution rate constants for major elements are summarized as a function of temperature in Fig. 2. Apparent activation energies have the same relationship as dissolution rate. Alkali metal and alkali earth metal ion have -20 to 40 kJ/mol apparent activation energy, due to a diffusion effect from the mineral surface. The existing reaction condition does not correspond to the critical reaction rate, but this condition is more applicable for natural water-rock interactions, because the nature of incongruent dissolution on the mineral surface controls fluid chemistry and metastable reaction processes. 

We have examined the effect of kiln aerodynamics on fluid mixing and combustion. It is equally important to look at the aerodynamic effect on dust carryover from rotary kilns processing mineral materials. Although the principles behind particle motion are related to granular flow which will be covered in Chapter 4, the interaction of the flow of fluid in the freeboard and the active layer surface of the kiln bed is an aerodynamic phenomenon. 

Fig. 12A,B- Reaction path calculations of sandstone-pore water interactions at 105 °C. A OAA absent B OAA present in pore water (3120mgkg acetate 58mgkg oxalate other input data summarized in Table 4). Dolomite is destabilized by the presence of OAA because of the ability of these anions to complex calcium and magnesium, thereby reducing the free ion activities. The final mineral assemblage, which represents reaction of a single pore volume of fluid with an arkose having 20% porosity, is not reported from studies of sandstone diagensis, implying that this much mineral reaction is unrealistic. Calculations of diagenetic alteration patterns (Table 5 Fig. 13) utilized amounts of reaction at log Zi = —4.5, —3.5, and —2.5. (Harrison and Thyne 1992)...

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