Chemical processes
AssigneeWoodsreef Mines Limited
InventorsPhillip S. B. Stewart, Jeremy J. Lees
Life of this patent
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Abstract
String-like agglomerates of chrysotile asbestos fibers are recovered from crude asbestos by first forming a stable gel structure of asbestos and dispersing agent, diluting the gel structure dispersion with water in a first dilution step to form a readily pourable dispersion without dilution of the concentration of dispersing agent to a level insufficient to maintain the asbestos fibrils in a dispersed state, and then, in a second dilution step, rapidly diluting the dispersion with water to reduce the concentration of dispersing agent to a level insufficient to maintain the dispersion, thereby forming agglomerates of the fibrils. Preferably, the dispersion is subjected to an orienting flow during or immediately after the second dilution step to form string-like agglomerates.
Claims17
A method for producing agglomerates of unit, or near unit, fibrils of chrysotile asbestos from crude chrysotile asbestos, comprising the steps of:
- (a) forming a stable gel structure of unit, or near unit, fibrils of asbestos by mixing the crude asbestos with an aqueous solution of an asbestos dispersing agent to disperse the fibrils to form the stable gel structure;
- (b) diluting the gel structure dispersion with water in a first dilution step to form a readily pourable dispersion without diluting the concentration of the asbestos dispersing agent to a level where it is insufficient to maintain the asbestos fibrils in a dispersed state;
- and
- (c) rapidly diluting the dispersion with water in a second dilution step sufficient to reduce the concentration of the asbestos dispersing agent to a level where it is insufficient to maintain the dispersion such that the dispersion of the fibrils collapses and agglomerates of the fibrils are formed.
A method of recovering string-like agglomerates of unit, or near unit, chrysotile asbestos fibrils from crude asbestos, comprising the steps of:
- (a) forming a stable gel structure of individual asbestos fibrils by mixing the crude asbestos with an aqueous solution of an asbestos dispersing agent effective to disperse the fibers to form a stable gel structure;
- (b) rapidly diluting the concentration of the asbestos dispersing agent in the gel structure sufficiently to reduce the concentration of the asbestos dispersing agent to a level where it is insufficient to maintain the asbestos fibrils in a dispersed state;
- (c) subjecting the dispersion, during or immediately after said dilution step, to an orienting flow, and
- (d) recovering the string-like agglomerates of unit, or near unit, asbestos fibrils formed in said orienting flow.
Dependencies are inferred from the claim text.