Granite coefficients

Quartz occurs in granite, sand, crystals, and sandstone. Quartz also has several crystalline varieties such as purple amethyst, colorless rock crystal, and yellow citrine. Flint, agate, and chert, etc. are other forms of quartz. Quartz is an excellent insulator. It does not break under temperature changes because of its low coefficient of expansion. Fused quartz transmits ultraviolet light. 

Measured mass related distribution coefficients for granite... 

Figure 4. Range of distribution coefficients for granite at 25°C (cf. Table V)...

Mass related distribution coefficients for granite. (Particle size 0.063-0.105 mm, contact time ... 

Differences between the observed distribution coefficients of a certain element at different concentrations are small. The only significant exception is Cs which has a higher distribution coefficient at low concentration than at high in the granite system (by a factor of less than two). This may in fact reflect the poor ion exchange capacity of the granite. 

Generally, a significantly increased distribution coefficient is obtained after a contact time of 6 months in comparison with 1 week (by a factor of less than five), especially for the tri-and tetravalent elements (and Ra) on granite. Evidently the diffusion of hydrolyzed products into the grains is a slow process. Radionuclide Species in Groundwater... 

Figure 6. Distribution coefficients as functions of contact time and surface to mass ratios for Cs, Sr, and Am on granite (25°C, Aq os)...

Table III. Sorption Coefficients for Technetium on Quartz, Granite, and Gabbro under Oxic Conditions...

Radon is slightly soluble in water, and obeys Henry s Law. At 20°C the partition coefficient (amount of radon per litre of water at equilibrium divided by the amount per litre of air) is 0.26. Despite the low solubility, water supplies derived locally from granite and metamorphic rocks can be an important source of airborne radon in dwellings (Nero Nazaroff, 1984 Hess etal., 1987). Radon is more soluble in fats and organic liquids, and the partition coefficient between air and human fat is about unity at 37°C. 

The surface sorption capacity is usually expressed as a surface sorption coefficient. In general, the surface distribution coefficient of U(VI) between the solution and the granite surface, K, (cm), is defined as ... 

Consider a cubic block whose sides are 5 cm long and a cylindrical block whose height and diameter are also 5 cm. Both blocks are initially at 20°C and are made of granite (k = 2.5 W/m °C and a = 1.15 X 10 m /s). Now both blocks are exposed to hot gases at 500°C in a furrrace on all of their surfaces with a heat transfer coefficient of 40 W/m °C. Determine the center temperature of each geometry after 10, 20, and 60 min. 

Perelman (1975) proposed the use of the coefficient of water migration (Cw), which is determined as the ratio of the concentration of the element in the dry residue of a water sample to the concentration of the element in the rock. In estimating the extent of involvement of an element in aqueous migration on a global scale we should know the ratio of the average content of the element in the dry residue of water stream to the abundance of this element in the continental granite layer. 

Further research has shown that replacement of granite rubble by quartz sand allows an increase if the coefficient of chemical resistance of RubCon up to 7% in a 36% solution of hydrochloric acid. 

The He concentration profiles expected in groundwaters for He diffusion through bulk granite (solid lines) with diffusion coefficients of 1.6 x 10 ° cm s (5 x 10 a ) assuming that... 

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