Patents Assigned to Woodsreef Mines Limited
  • Patent number: 4272495
    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.
    Type: Grant
    Filed: January 22, 1979
    Date of Patent: June 9, 1981
    Assignee: Woodsreef Mines Limited
    Inventors: Phillip S. B. Stewart, Jeremy J. Lees
  • Patent number: 4252603
    Abstract: A process of separating fibres from asbestos-bearing material which process comprises the steps by treating said asbestos-bearing material with a chemical agent capable of reacting with, or adsorbing on, asbestos fibres to form a dispersion, and agglomerating said dispersion, and wherein effluents containing said chemical agent are subjected to ultrafiltration prior to re-use in the process. The process given high yields of novel fibres characterized in that the said fibres provide reinforcement in cementitious compositions.
    Type: Grant
    Filed: January 15, 1979
    Date of Patent: February 24, 1981
    Assignees: ICI Australia Limited, Woodsreef Mines Limited
    Inventors: Nicholas Kharsas, Philip S. B. Stewart