Patents Assigned to Greenfield Environmental
  • Patent number: 5476994
    Abstract: The process for removal of metal-contaminated sediment includes dredging the sediment and removing large objects from the sediment, then removing smaller objects such as shell fragments with a first course screen. The remaining sediment slurry is processed through at least two screens covering a range of mesh sizes to separate the solids into three size/mesh fractions. Water extracted during the separation is processed through a series of hydrocyclones to separate any remaining solids and to allow the water to be recycled. The largest fraction of solids, the "sand fraction" has a low concentration of the metal and requires no further processing. The smallest fraction, which has passed through a mesh corresponding to the size of the most basic form of the metal ore, enters a screw classifier for dewatering after which it is appropriate for direct smelter recycling.
    Type: Grant
    Filed: May 6, 1994
    Date of Patent: December 19, 1995
    Assignee: Greenfield Environmental
    Inventor: George J. Trezek