Removal of Aqueous Lead and Copper Ions by Using Natural Hydroxyapatite Powder and Sulphide Precipitation in Cyanidation Process
- 1 Department of Metallurgy and Materials Science, Institute Technology of Saltillo, Saltillo, Mexico
- 2 Departament of Chemical Engineering and Metallurgy, University of Sonora, Hermosillo, Mexico
- 3 Departament of Chemical Engineering and Metallurgy, University of Sonora, Hermosillo, Mexico
- 4 Department of Metallurgy and Materials Science, Institute Technology of Saltillo, Saltillo, Mexico
- 5 Department of Chemistry, Institute Technology of Laguna, Torreon, Mexico
Abstract
Mining, ore processing, and smelting activities have contaminated soil and water resources with cyanide and heavy metals throughout the world. In-situ chemical immobilization is a remediation technology that decreases the concentra tions of dissolved ions of copper cyanide and lead hydroxides by adsorption or precipitation. T his study deals , with a process to recover lead hydroxides with natural hydroxyapatite powder and copper cyanide ions with sulphide precipi tation from solutions of the cyanidation process . This technology is based on inducing nucleated precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2.5 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 99% with 60 percent of copper purity and the cyanide ions associated with this complex the recovery was 90%. For the elimination of lead hydroxides ions from the aqueous cyanidation process with natural hydroxiapatite powder the recovery was 99%. The abundance of cow bones, its low price and non-aggressive nature towards the environment are advantages for its utilization in point of view of wastewater cleanup and Dore with higher quality.
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