Removal of metallic contents from the waters of the tailings deposit of the Mahr Tunel Concentrator Plant - Yauli, Junín, Peru

Abstract

The research carried out in the waters discharged from the tailings tank No. 6 of the Mahr Tunel concentrator plant, Yauli – La Oroya, promotes the use of calcium hypochlorite as an oxidizing agent and in a second stage the use of chloride ferric as a coagulant agent, with which it will be possible to remove the heavy metals contained in the tailings dam waters. Heavy metals present in ionic form in water include copper, lead, zinc, iron, arsenic and cadmium. These metals above the maximum permissible limits (MPL) are dangerous to human life and the environment. Laboratory tests have been carried out, with the objective of determining the concentration and dosage required for the removal to be efficient and comply with the DS N° 010-2010- Maximum Permissible Limit-Mining and Metallurgical Effluents-MINAM. In the removal process, caustic soda at 26.3 ppm was used as a pH regulator to reach a pH of 8.6; Thus, the dose of 65.3 ppm of calcium hypochlorite and a dose of ferric chloride of 10 – 40 ppm was also obtained. The use of ferric chloride does not help in the removal, especially of iron, which is increased in the final effluent and therefore, its application is ruled out. Finally, with the application of caustic soda and calcium hypochlorite, the values present in the water remained below the LMP. These tests can be replicated in other tailings effluents but taking into consideration the characteristics of the effluent to be treated.