Pretreatment of Bauxite With Oxygen or Air At Elevated Temperature.
MacDonald-DJ; Zamzow-MJ; Shanks-DE
For Reference Only At Bureau Libraries :8 pages
A typical Jamaican bauxite was subjected to treatments at tempertures up to 440 deg c in oxygen or air; its leachability under Bayer process conditions was measured, and properties of its leached residue were observed. The objective was to decrease the amount of organic matter in bauxite or in leach liquor derived from it without impairing leachability. Techniques employed included heating bauxite under pressure in an autoclave (a closed system, in which water vapor and other gaseous products were confined and remained in contact with the bauxite) with oxygen or air, and in flowing oxygen at ambient pressure in a tube furnace (an open system). Leaching tests were done in a 600-ml stirred reactor. Results showed that treatment at temperatures above 160 deg c progressively diminished the bauxite's content of organic carbon. The bauxite's leachability was not impaired by high-temperature treatments except at temperatures higher than 300 deg c.
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