云南某金矿含氰废水处理工艺研究

Tests on Treatment Process of Cyanide-bearing Liquid Waste from a Gold Mine in Yunnan

云南某金矿采用传统氰化工艺生产黄金。为使该矿的含氰废水能达标排放,采用"次氯酸钠两段氧化+活性炭吸附"联合工艺对其进行了除氰试验。结果表明:在一段局部氧化反应的pH=10.5、m(NaClO)∶m(CN-)=2.5,二段完全氧化反应的pH=9.1、m(NaClO)∶m(CN-)=7,两段氧化反应的反应时间均为15 min条件下,废水经次氯酸钠两段氧化,游离氰根含量可由原来的45.01 mg/L下降到0.19 mg/L。两段氧化后的废水再用200 mg/L的活性炭吸附1 h,可使其游离氰根含量<0.05 mg/L,从而达到《生活饮用水卫生标准》和《工业企业设计卫生标准》的要求。

A gold mine in Yunnan province produces gold by the traditional cyanidation process. In order to make the cyanide-bearing wastewater reached the discharge standards,the joint process of＂two-stage oxidation of sodium hypochlorite ＋ activated carbon adsorption＂was carried out to remove cyanide. The results showed under the conditions of m（ NaClO） ∶ m（ CN^-） =2. 5,pH =10. 5 in the first stage,and with m（ NaClO） ∶ m（ CN^-） =7,pH =9. 1 in the second stage for reaction time 15 min respectively,the content of cyanide in the liquid waste was declined to 0. 19 mg / L from the primary 45. 01 mg / L by twice oxidation of sodium hypochlorite. Then,the treated liquid waste was optimized by the activated carbon adsorption process for 1h,and the content of cyanide was declined to less than 0. 05 mg / L,which meets the requirement of＂Standards for Drinking Water Quality＂and＂Hygienic Standards of Industrial Enterprises Design＂.