Cements, digestion methods

Claveus had noted that if an equal quantity, or less, of philosophical Mercury be mixed with philosophical Gold, and they are digested or cemented together. . . the philosophical Gold will perfect more or less of the Mercury and this, Stahl comments thereafter, seems not improbable. The problem was how to make philosophical Gold. One way was to produce it from common gold, but Stahl records another method in which vitriol (sulfates of iron or copper usually) were used. The reason given for the use of... 

Inorganic Samples. Wet digestion, fusion, and pressure dissolution are common methods for the dissolution of metals, slags, ores, minerals, rocks, cements, and other inorganic materials and products. If the final solutions contain more than about 0.5% of dissolved material, the standards should also contain the major constituents in order to match the viscosity and surface tension. 

Bauxitland Cement. See kuhl cement. Bayer Process. A process for the extraction of alumina from bauxite, invented by K. J. Bayer in 1888. The bauxite is digested with hot NaOH and the AI2O3 is then extracted as the soluble aluminate. Because of this method of extraction, the calcined alumina used in the ceramic industry usually contains small quantities of Na20. 

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