云南某金矿含氰废水处理工艺研究

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。

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

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”.