In this paper, we report leaching of precious and scattered metals such as gold (Au), copper (Cu), nickel (Ni), zinc (Zn), iron (Fe), and lead (Pb) from printed circuit boards of scrap mobile phones by hydrometallurgical process using inorganic acid, organic acid and base. The amount of metals leached by different leachants are quantified using atomic absorption spectroscopy. Among various inorganic acids, aqua regia (mixture of nitric acid (HNO₃) and hydrochloric acid) is found to be the strongest leachant for most of the metals such as Zn (2.04 wt %), Fe (17.90 wt %), Ni (0.66 wt %), Pb (5.86 wt %) and Au (0.04 wt %). The basic leachant, ammonium thiosulphate is found to be very effective in leaching of Au (0.03125 wt %). The dissolution of Cu in HNO₃ gives the highest amount of Cu in the solvent, that is, ∼ 7.52 wt %. The metallic phases present in the electronic waste before and after leaching are identified by X-ray diffraction analysis. The microscopic structure has been studied using a scanning electron microscope which depicts erosion of the structure after leaching.

在本文中，我们报告了从废料印刷电路板上浸出的贵金属和零散金属，例如金（Au），铜（Cu），镍（Ni），锌（Zn），铁（Fe）和铅（Pb）手机采用湿法冶金工艺，使用无机酸，有机酸和碱。使用原子吸收光谱法对不同浸出剂浸出的金属量进行定量。在各种无机酸中，王水（硝酸（HNO ₃）和盐酸的混合物）被发现是大多数金属（例如Zn（2.04 wt％），Fe（17.90 wt％），Ni（ 0.66wt％），Pb（5.86wt％）和Au（0.04wt％）。发现碱性浸出剂硫代硫酸铵对浸出Au（0.03125 wt％）非常有效。Cu在HNO _3中的溶解溶剂中铜的含量最高，约为7.52 wt％。通过X射线衍射分析鉴定浸出之前和之后电子废物中存在的金属相。使用扫描电子显微镜研究了微观结构，其描绘了浸出后结构的腐蚀。