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

Patent · Tue Dec 31 23:00:00 EST 1996

OSTI ID:871024

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

---

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
• 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

/210/423/
accomplished
acid
adjustment
agents
appropriate
available
catechol
chelating
chelating agent
chelating agents
collected
competing
complex
complexes
containing
containing waste
copper
cyanide
destroyed
dilute
dilute acid
displacement
disposed
disrupted
electroplating
freed
hydroxamate
iron
leach
management
metal
metal complex
metal-cyanide
metals
mineral
mining
nickel
nonhazardous
oxidation
oxidative
physical
physical separation
polyethyleneimine
polymer
polymer-metal
polymers
preferred
process
processes
processing
processing waste
recovered
recycled
related
relates
released
rendering
reuse
separation
soluble poly
soluble polymer
streams
strong
techniques
ultrafiltration
waste
waste stream
waste streams
water-soluble
water-soluble polymer
water-soluble polymers