Correlation between dynamic leach test results and geochemical observations

A test method based on partial leachant exchange at constant intervals until leachate concentrations become stabilized has been used to obtain a data-base in evaluating long-term leaching patterns. Applied to basalt and granite specimens and compared with ground-water analyses, correlations which can be used in long-term leachability extrapolations have been established. They are based on the following principles: (1) control of solubilities of major components by combined aluminosilicate species; (2) continued increase in levels of soluble species, e.g., Na/sup +/ of SO/sub 4//sup 2 -/, along with Ca/sup 2 +/ and K/sup +/, followed by slowing down, probably due to the presence of selectivity leachable phases; (4) initial retardation of Mg and Fe leaching followed by regrowth as sorption sites become saturated.