In this paper, the leaching behavior of the major metals present in printed circuit boards waste is evaluated, aiming at its recycling by hydrometallurgy. Several leachants were compared (sulfuric, hydrochloric and nitric acids, at 2 M H+ concentration), at temperatures of 25ºC and 90ºC and 4 hours of reaction time. Sulfuric acid leaching was not very promising concerning metals dissolution being only effective for iron. Hydrochloric acid allowed the leaching up to 60% of tin and about 50% of lead, as well as the iron. Nitric acid was the most efficient leachant due to its oxidizing properties. Recoveries of 90% or more for copper, iron, nickel and zinc were achieved at the higher temperature. Lead was also dissolved (up to 80%), as well as silver (more than 70%). These results show that the hydrometallurgical recovery of most of the metals present in PCB’s scrap is a technically feasible alternative that shall be considered and evaluated.
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机译：在本文中，评估了印刷电路板废料中主要金属的浸出行为，旨在通过湿法冶金对其进行回收。在25ºC和90ºC的温度以及4小时的反应时间下，比较了几种浸出液（硫酸，盐酸和硝酸，浓度为2 M H +）。关于金属溶解仅对铁有效，硫酸浸出的前景并不乐观。盐酸允许浸出多达60％的锡和约50％的铅以及铁。硝酸由于其氧化特性而成为最有效的浸出剂。在较高温度下，铜，铁，镍和锌的回收率达到90％或更高。铅和银（超过70％）也被溶解（高达80％）。这些结果表明，湿法冶金回收PCB废料中存在的大多数金属是技术上可行的替代方案，应予以考虑和评估。
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