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

Patent · Wed Jan 01 00:00:00 EST 1997

OSTI ID:871024

Smith, Barbara F ^[1]; Robinson, Thomas W ^[1]

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1. Los Alamos, NM

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.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• Assignee: Regents of University of California (Los Alamos, NM)
• Patent Number(s): US 5643456
• OSTI ID: 871024
• Country of Publication: United States
• Language: English

Related Subjects

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/