Papers by Keyword: Aqua Regia

Abstract: Waste deposited in ponds can also contain precious metals, as trace elements. Preliminary studies have shown, by chemical analysis, the presence of gold and silver in waste steel. This paper presents some preliminary aspects of experimental work related to gold recovery opportunities from sideritic waste, Teliuc type - stored as a pond and future directions in research. There were two distinct phases considered: gravimetric concentration and removal of three layers from the experimental material, respectively, the treatment of the concentrate with “aqua regia”.

Abstract: This work compared the effect of nitric acid and chloride acid systems on dissolving precious metals of Electrical and Electronic Equipments (EEE). As a result of the revolution of informatics technology, the production of EEE is rapidly increasing in the world. Due to economic growth, technological innovation and market expansion of EEE there is a significant increase in waste of EEEs (WEEE) that presents a new environmental challenge.The results show that the best recovery of gold can be obtained via aqua regia (3HCl=HNO3), with concentration of 1/10 gr/L. The reaction temperature has little effect on the extent of extraction.

Abstract: This paper draws out a new method to determine the chromium content in diamond tools of metal bond. Used aqua regia to dissolve the sample, perchloric acid emits smoke to oxidize the Cr³⁺ to Cr₂O₇^2- by smoke emission .than used reducing agent of Fe²⁺ standard solution to measure quickly the chromium in the diamond tools of metal bond. This method is verified by quality control chart , this method saves time and practical.