Wastewater of a silver processing plant at the Eti Gumus plant located at Kutahya, Turkey was treated with an acidification, volatilisation and reneutralisation (AVR) process for cyanide recovery as a preliminary treatment, and with ozone and ozone/UV light plus catalysts as a secondary treatment. Average NaCN concentrations of slurry with AVR were reduced from 900 ± 50 ppm to 50 ± 10 ppm. Then, oxidation of cyanide in the presence of titanium dioxide, zinc sulphate and copper sulphate as catalysts was investigated and variations in CN− and CNO− ion concentrations were measured with a cyanide electrode and ion chromatography, respectively. The reaction time reduced to 12 min with the addition of catalysts when ozone consumption was 0·100 g min−1 after 25 min with ozone alone and 0·071 g min−1 after 20 min for the ozone/UV system. As a result, the most effective method to achieve appropriate discharge values for cyanide with respect to environmental protection laws was the ozone/UV/TiO2 system with AVR recovery for the effluents of silver ore leaching.
HABASHIF.: ‘One hundred years of cyanidation’, CIM Bull, 1987, 80, 108–114.
2.
YARARB.: ‘Cyanides in the environment and their long-term fate’, 17th International Mining Congress and Exhibition of Turkey, 2001, 84–92.
3.
BOTZM. M., STEVENSONJ. A., WILDERA. L., RICHINSR. T., MUDDERT. I. and BURDETTB.: ‘Cyanide recovery and destruction’, Eng. Min..1, 1995, VI117.
4.
BOTZM. M. and MUDDERT. I.: ‘Cyanide recovery for silver leaching operations application of CCD-AVR circuits’, Randol silver forum, Denver, CO, 1998.
5.
MUDDERT. I. and GOLDSTONEA.: ‘The recovery of cyanide from slurries’, Proc. International Gold Expo Conference, Reno, Nevada, 1989.
6.
RDEROSP.A., MOLNARR. and BASAF.: ‘Treatment of a high-cyanide waste solution for cyanide and metal recovery’, CIM Bull., 1996, 89, 153–156.
7.
LEAOV. A., CIMINELLIV. S. T. and COSTAR.: ‘Cyanide recycling using strong-base ion-exchange resins’, J. MM., 1998, 50, 71–74.
8.
EPAU.S.: ‘Ore mining and dressing point category effluent limitations guidelines’, 40 CFR 440, 1998.
9.
KNORREH. and GRIFFITHSA.: ‘Cyanide detoxification with hydrogen peroxide using the Degussa process’, (ed. van ZylD.), Cyanide and environment, 1984.
10.
QUAMRULA. M., GRIFFITHSM. and JUCEVICE. P.: ‘Detoxification of spent heap leach with hydrogen peroxide’, J South Afr. Inst. MM. Metal., 1989, 87, 279–283.
11.
SERPONEN., BORGARELLOE. and PELIZZETTIE.: ‘Photoreduction and photodegradation of inorganic pollutants: I. cyanides’,(ed. SchiavelloM.), Photocatalysis and environment, Amsterdam, Kluwer, 1988, 499–526.
12.
YOUNGC. A., CASHINS. P. and DIEBOLDF. E.: ‘Photolysis for cyanide and nitrate remediation of water’, (ed. MisraM.), Separation processes: heavy metals, ions and minerals, Warrendale, PA, TMS, 1995, 61–80.
13.
ROBBINSG. H.: ‘Historical development of the INCO 502/air cyanide destruction process’, CIM Bull., 1996, 89, 63–69.
14.
INCO: ‘Cyanide destruction: the Inco502/air process’, Inco Exploration and Technical Services, 1993.
15.
STAUNTONW, SCHULTZR. S. and GLENISTERD. J.: ‘Chemical treatment of cyanide tailings’, Proc. Randol Gold Conf., Randol Int. Ltd., Golden Co., 1988, 85–86.
16.
ZAIDIA. and WHITTLEL.: ‘Evaluation of the full scale alkaline chlorination treatment plant at Giant Yellowknife Mines Ltd’, Report of Wastewater Technology Center—Environment Canada, Burlington, Canada, 1987.
17.
EPAU.S.: ‘Final report —photo-assisted electron transfer reactions of application to mine wastewater cleanup: metal-complexed cyanides mine waste technology program activity IV’, Project 3A, prepared by Montana Tech., Univ. Montana and MSE-TA, Inc., 1998.
18.
HIDAKAH., NAKAMURAT., ISHIZAKAA., TSUCHIYAM. and ZHAOJ.: ‘Heterogeneous photocatalytic degradation of cyanide on TiO2 surfaces’, J. Photochem. Photobio, 1992, 66, 367–374.
19.
WEATHINGTONB. C.: ‘Destruction of cyanide in waste waters: review and evaluation’, Project Summary, U.S. EPA Report No. EPA/600/2-88/031, Water Engineering Research Laboratory, Cincinnati, OH, 1988.
20.
YOUNGC. A. and JORDANT. S.: ‘Cyanide remediation: current and past technologies’, In: Proc. of the 10th Annual Conference on Hazardous Waste Research, Kansas State Univ., Manhattan, Kansas, 1995, 104–129.
21.
CARRILLO-PEDROZAF. R., ALANSOF. N. and SALASA. U.: ‘Cyanide oxidation by ozone in cyanidation tailings’, Mineral. Eng., 2000, 13, 541–548.
22.
BELTRANF. J., JF.. RD/AS and R. M. ESPINASO: ‘Catalytic ozonation of oxalic acid in aqueous TiO2 slurry reactor’, AppL Catalysis B: Environ., 2002, 39, 221–231.
23.
PARGAJ. R., SHUKLAS. S. and CARILLA-PEDROZAF. R.: ‘Destruction of cyanide waste solutions using chlorine dioxide, ozone and titania sol.’, Waste Manage., 2003, 23, 183–191.
24.
BOTZM. M: ‘Overview of cyanide treatment methods’, Mining Environmental Management, London, Mining Journal Book Ltd, 2001, 28–30.
25.
ILLIEP. and PODARIUM.: ‘Ozonation of cyanide ions and influence of catalyzer on oxidation’, (eds. OnalCeliks), Innovations in mineral and coal processing, Atak, Rotterdam, Balkema, 1998, ISBN90580890132, 823–827.
26.
LEGUBEB., KARPELN. and LEITNERV.: ‘Catalytic ozonation: a promising advanced oxidation technology for water treatment’, Catalysis Today, 1999, 53, 61–72.
27.
APHA: ‘Standard methods for the examination of water and wastewater’, 14th edn, Washington, DC, American Public Health Association, 1975.
28.
CHIANGK., AMALR. and TRANT.: ‘Photocatalytic oxidation of cyanide’, J. Mol Catalysi, 2003, 193, 285–297.
29.
VAPURH.: ‘Investigation of cyanide recovery from wastewater of silver plant [in Turkish]’, unpublished PhD thesis, Cukurova University, Adana, 2004, 1–170.
30.
SMITHA. and MUDDERT.: ‘Chemistry and treatment of cyanidation wastes’, London, Mining Journal Books Ltd, 1991.
31.
AVEDESIANM. M., SPIRAP. and KANDUTHH.: ‘Stripping of HCN in a packed tower’, Can..1. Chem. Eng., 1983, 61, 801–806.
32.
RDEROSP.A., KOREND., MCNAMARAV. M. and BINVIGNATJ.: ‘Cyanide recovery from a gold mill barren solution containing high levels of copper’, CIM Bull., 1998, 91, 73–81.
33.
SERPONEN., LAWLESSD., TERZIANR., MINEROC. and PELIZZETTIE.: ‘Heterogeneous photo catalysis: photochemical conversion of inorganic substances in the environment’, Photochemical conversion and storage of solar energy, Amsterdam, Kluwer, 1991, 451–475.
34.
AGUADOJ., GRIEKENR., MUNOZM. J. P. and MARUGANJ.: ‘Removal of cyanides in wastewater by supported Ti02-based photocatalysts’, Catalysis Today, 2002, 75, 95–102.
