DISSOLUTION OF CLAY MINERALS IN DILUTE ORGANIC ACIDS AT ROOM TEMPERATURE

TWO GRAMS EACH OF REPRESENTATIVE CLAY MINERALS WERE SHAKEN AT ROOM TEMPERATURE IN DISTILLED WATER, AND IN 0.01M ASPARTIC, CITRIC, SALICYLIC, TARTARIC, AND TANNIC ACIDS (REPRESENTATIVE OF COMPONENTS OF HUMIC ACID). ALIQUOTS OF CENTRIFUGED SOLUTION, UP TO 102 DAYS DISSOLUTION, WERE ANALYZED FOR SILICON, IRON, ALUMINUM, IRON, MAGNESIUM, CALCIUM, SODIUM, AND POTASSIUM. THE TOTAL WEIGHT OF CLAY MINERALS DISSOLVED BY STRONGLY COMPLEXING ORGANIC ACIDS EXCEEDS THAT DISSOLVED BY DISTILLED WATER BY FACTORS 5 TO 75. DISSOLVED SILICON IN STRONGLY COMPLEXING ACID SOLUTIONS EXCEEDED 2-35 TIMES ITS CONCENTRATION IN DISTILLED WATER; DISSOLVED ALUMINUM, 3-500 TIMES. ASPARTIC, AN AMINO-ACID, DISSOLVED CALCUM AND MAGNESIUM BEST. CLAY MINERALS DISSOLVE INCONGRUENTLY IN DISTILLLED WATER, SILICON PREFERENTIALLY TO A ALUMINUM. IN ALL ACIDS USED, SILICON INCONGRUENTLY EXCEEDS ALUMINUM DISSOLVED FROM ARIZONA AND WYOMING SMECTITES, SEMI-PLASTIC REFRACTORY CLAY, ALSO FOR ILLITES IN SALICYLIC ACID, AND KEOKUK KAOLINITE IN CITRIC AND TANNIC ACID. CONGRUENT DISSOLUTION, OR ALUMINUM INCONGRUENTLY EXCEEDING SILICON, 1.3-1.6:1, OCCURRED WITH BUEKER FLINT CLAY, GEORGIA KAOLINITE, AND ILLITES IN CITRIC, TARTARIC, AND TANNIC ACIDS. PREFERENTIAL SOLUBILITIES OF EITHER SILICON OR A ALUMINUM FROM CLAY MINERALS INDICATE GENETIC MECHANISMS FOR POSSOLS, LATERITES, KAOLIN (ESPECIALLY MOORVERWITTERUNG TYPE), AND BAUXITES. GEOLOGIC AND PEDOLOGIC EXAMPLES ARE CITED. /AUTHOR/