The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 08, 1980
Filed:
Aug. 25, 1978
William M Goldberger, Columbus, OH (US);
Bhupendra K Parekh, Columbus, OH (US);
Bobby P Faulkner, New Berlin, WI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Metal beads, e.g., magnesium beads, or Mg alloy beads, having a high degree of rotundity, and having a thin coating of sludge or slag ingredients, are recovered from entrapment in a friable contiguous material of sludge or slag material by (a) a primary milling of the friable matrix in a hammer mill or impact mill, (b) screening the material to collect the desired particle sizes, (c) attriting the material in a secondary milling operation to further, and gently, grind sludge material from around the beads, and (d) separating the rotund beads from the pulverized matrix material by using a shape-classifier, such as a slanted shaker table. The material may be treated beforehand by melting the metal-containing sludge or slag, adding a flux or emulsifier material with stirring to cause dispersion of the metal into a relatively narrow particle size range and then freezing the molten mixture. The invention is especially useful in the case of Mg beads, since Mg beads are malleable and pyrophoric.