Selective dissolution and formula derivation of clay vermiculite from some Tuscan soils

Abstract

The chemical composition and structural characteristics of clays from samples of eight Tuscan soils were investigated. Using simple selective dissolution method (successive boiling in 1 N HCl and 0"5 N NaOH) it was possible to distinguish two types of low charge dioctahedral vermiculite; one easily HC1 soluble the other practically insoluble.

Effect of pedogenic clay minerals on the sorption of copper in a Luvisol B horizon

“…Very weak reverse correlation was found between total Al and Mg content. The structural formula for Group I represents an intermediate grade between HIV (Kirkland and Hajek, 1972) and vermiculites from soils formed on sedimentary rocks (Ristori et al, 1974).…”

Composition and Origin of Smectite in Soils Derived from Basalt in Northern Ireland

“…The low temperature of smectite dehydroxylation in the study clays precluded quantitative determination of kaolinite by DTA or by the dissolution procedure of Hashimoto and Jackson (1960). Acid treatments have been used for the selective dissolution of chlorite (Brindley, 1961) and vermiculite (Ristori et al, 1974). The partial dissolution of smectite at low pH during CEC determinations (Curtin, 1979) suggested that smectite might be selectively dissolved using dilute acid.…”

“…The partial dissolution of smectite at low pH during CEC determinations (Curtin, 1979) suggested that smectite might be selectively dissolved using dilute acid. The smectite was completely dissolved by an acid dissolution procedure similar to that of Ristori et al (1974). The residues consisted of kaolinite, mica, and quartz with a trace of feldspar in the clay separates, whereas quartz, augite, and feldspar remained in the silt and sand separates (Figures 1 and 2).…”

Composition of Smectite from Maastrichtian Sediment of the Afikpo Basin, southeast Nigeria

“…The low temperature of smectite dehydroxylation in the study clays precluded quantitative determination of kaolinite by DTA or by the dissolution procedure of Hashimoto and Jackson (1960). Acid treatments have been used for the selective dissolution of chlorite (Brindley, 1961) and vermiculite (Ristori et al, 1974). The partial dissolution of smectite at low pH during CEC determinations (Curtin, 1979;Freed and Peacor, 1989) suggested that smectite might be selectively dissolved using dilute acid.…”

“…The partial dissolution of smectite at low pH during CEC determinations (Curtin, 1979;Freed and Peacor, 1989) suggested that smectite might be selectively dissolved using dilute acid. The smectite was completely dissolved by an acid dissolution procedure similar to that of Ristori et al (1974). The residues consisted of kaolinite, mica and quartz with a trace of feldspar in the clay separates, whereas quartz, augite and feldspar remained in the silt and sand separates (Figs 2 and 3).Chemical analyses of the HCl and NaOH extracts of the sand, silt and clay separate from the Obotme samples are given in Table 3.…”