Synthesis of kaolinite by homogeneous precipitation at room temperature

Abstract

A B ST R ACT: A method of precipitation in homogenous solution has been used for the synthesis of kaolin minerals at room temperature. The method consists essentially in producing conditions for which a sufficiently slow ratc of precipitation is maintained. In the particular case described in this paper, the conditions for homogenous precipitation are obtained by addition of an anion exchange resin in the OH form to an acidic solution (pH ~ 4) of sodium silicate and aluminium chloride or acetate.The mineral species synthesized in each particular case depend on the kind of anions present in the original solution (chloride or acetate) and also on the nature of the exchange resin used.

Palygorskite-Sepiolite Clays of Lebrija, Southern Spain

“…Sepiolite crystallization should take place under conditions similar to those of the homogeneous precipitation, 4 noted for kaolinite, palygorskite, sepiolite, and other phyllosilicates by La Iglesia and Martin Vivaldi (1975), La Iglesia et al (1976), and La Iglesia (1977Iglesia ( , 1978. These conditions are more likely in natural environments than those proposed by other authors for the synthesis of these clay minerals at room temperature (e.g., Siffert, 1962;Wollast et al, 1968).…”

Kaolinite Synthesis. I. Crystallization Conditions at Low Temperatures and Calculation of Thermodynamic Equilibria. Application to Laboratory and Field Observations

“….) of gels (Gillis and Dekeyser, 1962;De Kimpe et al, 1964; Van Oosterwyck-Gastuche, this work), (b) slow dissolution of crystalline phase (Estroule, 1969;Kittrick, 1970), (c) homogeneous precipitation, produced by (i) slow change in pH (La Iglesia and Serna, 1974;La Iglesia and Martin Vivaldi, 1975), (ii) hydrolysis processes (La Iglesia et al, 1974Iglesia et al, , 1976, (iii) decomposition of complexes (Siffert, 1962;Wey and Siffert, 1962;Linares and Huertas, 1971a, b;La Iglesia and Martin Vivaldi, 1972;Hem and Lind, 1974;Lind and Hem, 1975) 9 It is of interest that a variation in the rate process is observed when parameters other than temperature (and evidently concentration) change. Attempts to synthesize kaolinite or gibbsite that produced amorphous phases can be related to the presence of large anions inhibiting those crystallizations, such as chlorides, sulfates, or perchlorates.…”

“…Kaolinite was obtained for the first time in alkaline medium (La Iglesia and Serna, 1974). The efficiency of H30 + resins in stabilizing the AI vt form, in the pH range in which otherwise the AI Iv form is stabilized is thus evidenced (see Gastuche and De Kimpe, 1959 This fact must still be correlated with data from La Iglesia and Martin Vivaldi (1975) who obtained a far better yield in kaolinite from similar experiments carried out in an acidic medium. Here also more crystalline product is obtained from the carboxylic resins than from the sulfonic ones.…”

In-Situ Clay Formation: New Technology for Stable Containment Barriers

“…Researchers at the University of Colorado and the University of Wisconsin are the primary investigators for this work. The approach has been to reproduce experimental designs from a number of published studies in which clay products were identified (e.g., Decarreau 1980Decarreau , 1981Decarreau and Bonnin, 1986;Decarreau et al, 1987;Flehmig, 1992;Harder, 1971Harder, , 1974Harder, , 1976Harder, , 1978Hem and Lind, 1974;La Iglesia Fernandez and Martin Vivaldi, 1973;La Iglesia and Martin-Vivaldi, 1975;Serna, 1974, Linares andHuertas 1971a,b;Siffert, 1962;Siffert and Wey, 1973). We have also synthesized an anionic clay called a layered double hydroxide (Cavani et al, 1991) which has a naturally occurring mineral counterpart called a hydrotalcite (e.g., Taylor and McKenzie, 1980).…”