Global Patent Index - EP 0439536 A4

EP 0439536 A4 19911127 - CYANIDE RECOVERY PROCESS

Title (en)

CYANIDE RECOVERY PROCESS

Publication

EP 0439536 A4 19911127 (EN)

Application

EP 89912367 A 19891020

Priority

  • NZ 23053289 A 19890901
  • US 26138688 A 19881021

Abstract (en)

[origin: WO9004655A1] A process for removing and recovering cyanide from a cyanide-containing mixture. A cyanide-containing waste stream (12) is treated in a pH adjustment zone (14) by addition of acidifying agent (16) in order to obtain a stream having a pH between about 6 and about 9.5. The pH adjusted stream is then transferred (18) from zone (14) to a volatilization zone (20), where HCN is transferred from the liquid phase to the gas phase using a volatilization gas (19). The stream of volatilized HCN and volatilization gas is removed from zone (20) and transferred into a cyanide recovery zone (26) to which basic material is fed (22). The treated tailings can be removed (28) and contacted in zone (31) with alkaline material (35) to readjust the pH upward to a range of about 9.5 to about 10.5 in order to precipitate metals. The resulting pH adjusted tailings (32) can then be impounded (34).

IPC 1-7

C22B 11/08; C01C 3/08

IPC 8 full level

C22B 11/08 (2006.01)

CPC (source: EP)

C22B 11/08 (2013.01); Y02P 10/20 (2015.11)

Citation (search report)

  • No further relevant documents have been disclosed.
  • See references of WO 9004655A1

Designated contracting state (EPC)

AT BE CH DE FR GB IT LI NL SE

DOCDB simple family (publication)

WO 9004655 A1 19900503; AU 4350889 A 19900426; AU 626332 B2 19920730; CA 1318480 C 19930601; CA 1318768 C 19930608; EP 0439536 A1 19910807; EP 0439536 A4 19911127

DOCDB simple family (application)

US 8904696 W 19891020; AU 4350889 A 19891018; CA 603590 A 19890622; CA 612912 A 19890925; EP 89912367 A 19891020