Abstract

GOMEZ-BELLI, Omar et al. Can I borrow your broken gold necklace for my chemistry lab?. Educ. quím [online]. 2019, vol.30, n.2, pp.70-77.  Epub Nov 15, 2019. ISSN 0187-893X.  https://doi.org/10.22201/fq.18708404e.2019.2.67501.

A laboratory experiment on the recovery of gold from an obsolete piece of jewelry was developed. The gold leaching system consists of K3[Fe(CN)6] (potassium ferricyanide), NaCl (sodium chloride), O2 (oxygen) and NaOH (sodium hydroxide); K3[Fe(CN)6] acts as a non-toxic source of cyanide, as well as an oxidizing agent (along with oxygen). Dicyanoaurate ([Au(CN)2]-) obtained in this process is isolated and characterized by spectroscopic methods. Due to the relative simplicity of this operation and the low toxicity of the reagents required, it can be performed in any educational laboratory. This experiment gives students practice with leaching processes, which are of great importance in the mining industry.

Keywords : Hands-On Learning; Inorganic Chemistry; Metallurgy.