Patents Assigned to Silrec Systems, Inc.
  • Patent number: 4021319
    Abstract: A method of electrolytically removing silver from a photographic fixer solution comprising the steps of placing the photographic fixer solution in a cell having an anode chamber and a cathode chamber, with said chamber being separated by a diaphragm having a pore size of between about 1.0 microns to 500 microns and applying a direct current across the anode and cathode to create a current density of between about 0.001 and 5 amperes per square inch at the cathode to thereby cause argentic oxide to precipitate at the cathode and an equivalent amount of elemental sulfur to precipitate at the anode. The cell is preferably maintained at a temperature of between about 20.degree. C. and 60.degree. C. The cell can be operated as a flow cell by maintaining a hydraulic head between the chambers to determine the flow across the diaphragm. When the cell is operated as a flow cell, a minimum specific amount of photographic fixer must be conveyed to the cell to prevent oxidation of sulfur and escape of SO.sub.2 gas.
    Type: Grant
    Filed: September 24, 1975
    Date of Patent: May 3, 1977
    Assignee: Silrec Systems, Inc.
    Inventor: Karl Moeglich
  • Patent number: 4021320
    Abstract: The present invention relates to a method of electrochemically removing silver in the form of AgO from a photographic fixer solution containing silver ions without destroying the utility of the solution comprising the steps of applying alternating current having a frequency of between about 0.5 Hz and 800 Hz and a current density of between about 0.1 and 20 amperes per square inch across electrodes immersed in said solution to cause AgO to precipitate at the electrodes. The method can also be practiced above the range of about 20 amperes per square inch at the cost of destroying the utility of the solution. The method can also be used to remove silver in the form of AgO from other solutions.
    Type: Grant
    Filed: September 24, 1975
    Date of Patent: May 3, 1977
    Assignee: Silrec Systems, Inc.
    Inventor: Karl Moeglich