废LCD显示器背光源模组拆解过程中汞的释放特征

Release characteristics of mercury in the backlight units during waste processing of LCDs

随着2013年首个全球汞排放公约的获得通过,含汞废物受到国际社会的广泛关注,中国对于汞污染排放的管理和整顿力度将逐步加大。由于在废液晶显示器(liquidcrystal display,LCD)拆解过程中,背光源模组中所含的汞较易释放扩散出来,受到研究者的普遍重视。该文就废LCD背光源中汞的存在状态、LCD拆解过程中背光灯管破碎后汞的转移路径和释放特征以及废LCD拆解行业所产生的汞排放总量等方面展开研究,并得出以下结论:首先,对于单根冷阴极荧光灯背光源(backlight cold cathode fluo-rescent lamp,BCCFL)而言,在使用过程中会有总质量1/3左右的汞因与灯管材料发生反应而不再以易检测到的形式存在,2/3的汞则留在灯管内;其次,每吨废LCD液晶电视会产生含汞的背光源模组约76.8kg;再次,对于废LCD液晶电视拆解行业而言,每年有超过1t汞通过不同途径进入环境中,其中约200kg以汞蒸气形式进入大气环境中。

As the Minamata Convention on Mercury comes into effect in 2013, mercury-containing wastes must be more carefully processed by the international community. The Chinese government has been addressing mercury pollution control in recent years. The dismantling of waste liquid crystal displays （LCD） can easily result in the release of mercury in the backlight which must he carefully handled. This study analyzes the presence of mercury in the baeklight, the transfer path and release characteristics of the mercury once the backlight is broken, and the total quantity of the mercury generated by the waste LCD dismantling industry. About 1/3 of the mercury reacts with the glass during use of the backlight with about 2/3 left in the lamp vessel. There is approximately 76.8kg of backlight per ton of waste LCD, which should be treated as hazardous waste. The waste I.CD TV dismantling industry then releases more than 1 t of mercury into the environment through various channels per year, of which about 200 kg of the mercury vapor goes into the atmosphere.