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Title: Process for the displacement of cyanide ions from metal-cyanide complexes

The present invention relates to water-soluble polymers and the use of such water-soluble polymers in a process for the displacement of the cyanide ions from the metal ions within metal-cyanide complexes. The process waste streams can include metal-cyanide containing electroplating waste streams, mining leach waste streams, mineral processing waste streams, and related metal-cyanide containing waste streams. The metal ions of interest are metals that give very strong complexes with cyanide, mostly iron, nickel, and copper. The physical separation of the water-soluble polymer-metal complex from the cyanide ions can be accomplished through the use of ultrafiltration. Once the metal-cyanide complex is disrupted, the freed cyanide ions can be recovered for reuse or destroyed using available oxidative processes rendering the cyanide nonhazardous. The metal ions are released from the polymer, using dilute acid, metal ion oxidation state adjustment, or competing chelating agents, and collected and recovered or disposed of by appropriate waste management techniques. The water-soluble polymer can then be recycled. Preferred water-soluble polymers include polyethyleneimine and polyethyleneimine having a catechol or hydroxamate group.
 [1];  [1]
  1. (Los Alamos, NM)
Issue Date:
OSTI Identifier:
Regents of University of California (Los Alamos, NM) LANL
Patent Number(s):
US 5643456
Contract Number:
Research Org:
Los Alamos National Laboratory (LANL), Los Alamos, NM
Country of Publication:
United States
process; displacement; cyanide; metal-cyanide; complexes; relates; water-soluble; polymers; metal; waste; streams; containing; electroplating; mining; leach; mineral; processing; related; metals; strong; iron; nickel; copper; physical; separation; polymer-metal; complex; accomplished; ultrafiltration; disrupted; freed; recovered; reuse; destroyed; available; oxidative; processes; rendering; nonhazardous; released; polymer; dilute; acid; oxidation; adjustment; competing; chelating; agents; collected; disposed; appropriate; management; techniques; recycled; preferred; polyethyleneimine; catechol; hydroxamate; water-soluble polymers; physical separation; waste stream; chelating agents; chelating agent; dilute acid; waste streams; metal complex; soluble polymer; containing waste; water-soluble polymer; soluble poly; processing waste; /210/423/