湿法技术从废弃线路板中提取金银的研究

发布时间：2018-05-08 20:25

  本文选题：废弃线路板 + 硫氰酸盐　； 参考：《青岛科技大学》2015年硕士论文

【摘要】：伴随着电子产品普及和更新速度的加快,大量的电子垃圾—印刷线路板也在以惊人的速度增加。废弃印刷线路板给环境和人体所带来的危害以及其所含有的铜、金、银等金属资源,使得它的回收再利用越来越受到重视,也成为最近研究的热点。因此,开发一种经济高效且环境友好的湿法工艺回收电子废弃物中的金和银已成当务之急。本论文以废弃电脑印刷线路板为研究对象,通过将其经粉碎研磨处理后,将200目以下的废弃印刷线路板粉末用硝酸进行预处理,烘干以后经过消解,得出废弃电脑线路板中金和银的含量分别为0.0545 mg/g和0.281 mg/g。采用三种方法进行金和银的提取实验,得到的最佳浸取条件分别为：(1)在双氧水氧化条件下硫氰酸盐法浸取金和银：在中性条件下,固液比1：20,SCN浓度0.8 mol/L,添加7.5%(v/v)的双氧水(浓度为30%),温度20℃,浸取时间1 h,达到的最高浸取率：金88.37%,银78.43%；(2)存在铜和氨的条件下氨法浸取金和银：固液比1：60,氨水浓度25%-28%(w/w),Cu2+浓度3×10-2 mol/L,加入一定体积的(NH3)2S04,使pH在9-10之间,温度60℃℃,提取时间4 h,最高浸出率：金96.23%,银92.58%;(3)碘化法浸金：固液比为1：50,pH在8-9之间,KI浓度为0.2 g/mL, m(I2):m(KI)=1:8,氨水体积比为1%,温度20℃,反应时间1 h,金和银的最高浸出率分别为96%和88.24%。通过对硫氰酸盐法和氨法进行成本预算,得出双氧水氧化条件下硫氰酸盐法浸金和银的成本比较低,并以硫氰酸盐法为例进行了整体经济效益分析,得出处理1吨的废弃电脑线路板,可以获得180.4元的利润。硫氰酸盐法浸取金和银具有浸出速度快,毒性小,成本低等有点,并且该方法在中性条件下进行,对设备的腐蚀性较小,具有良好的环境和经济效益,符合当今社会环境保护和资源二次利用的发展趋势。
[Abstract]:With the rapid popularization and renewal of electronic products, a large number of electronic garbage-printed circuit boards are also increasing at an alarming rate. The harm of waste printed circuit board to the environment and human body and the copper, gold, silver and other metal resources make the recycling and reuse of printed circuit board become more and more important and become a hot spot of recent research. Therefore, it is urgent to develop an economical, efficient and environmentally friendly wet process to recover gold and silver from electronic waste. In this paper, waste printed circuit board (PCB) is used as the research object. After grinding and grinding, the waste PCB powder below 200 mesh is pretreated with nitric acid, then dried and digested. The results show that the contents of gold and silver in the waste computer circuit board are 0.0545 mg/g and 0.281 mg / g respectively. Three methods were used to extract gold and silver. The optimum leaching conditions were: 1: 1) under the condition of hydrogen peroxide oxidation, gold and silver were extracted by thiocyanate method: under neutral condition, gold and silver were extracted by thiocyanate method. Solid to liquid ratio of 1: 20% SCN concentration 0.8 mol / L, adding 7.5% v / v hydrogen peroxide (concentration 30 鈩，

本文编号：1862942