Quantitative and qualitative study of acid mines drainage (AMD) in Sungun copper mine tailings dump with emphasis on its refineability

In copper industries, mining has a great importance from the environmental point of view, as during this process many by-products are generated. Most of the mining tailings are sulfide minerals, which are oxidized just after they are extracted and exposed to the oxygen and water which consequently leads to produce acid mine drainage (AMD). Water management strategies are conducted to control Acid mine drainage (AMD). Generally, one of the most important methods to refine AMD and release it into the environment is treatment technology. By and large, (AMD) treatment methods are classified as active and passive systems. In the present study, the need for the treatment methods is investigated and then the optimum system is specified.

Sungun copper mine is located in Northwest of Iran, 130 km north of Tabriz and 30 km north of Varzeqan. Production rate of tailings in this mine is roughly 11.2 million tons per year which has over 3 square kilometers area in Pakhir valley. Samples of acidic drainage from Pakhir chay river were collected 7 times and transferred to the laboratory of Omran Zist Azma Company. Bbottles of polypropylene with capacity of 200 cc were used to gather samples for analyzing acidity, sulfate and TDS and bottles of HDPE with capacity of 250 cc were used to gather samples for analysing heavy metals (copper, iron and manganese) parameters. Moreover Concentrated nitric acid was used for stabilizing sample. Flow rate of the river was measured by Mouline (flow meter and flow cross section method) which was on average 32 liters per second.

Results show that pH, sulfate, copper and manganese parameters are higher than the standard threshold. Since, before release to the environment, the parameters must be lower than the standard limits, so this indicates the need for the treatment systems.

Mineral deposits pollution significantly affects the environment, especially the strong hydrological region of Songun copper mine with the production of acidic drainage, which must be in standard threshold for the accepting source. Therefore, treating AMD and then releasing into the environment is the best and definite management strategy. In order to treat acidic drainage, there are two main treatment methods containing active and passive systems. Different types of active and passive treatment systems often are used separately or in combination with each other. This combination is a suitable solution for removing heavy metals from mines acidic drainage. The choice of these systems depend on the acidic drainage chemical composition, type of ore, topographic and climatic conditions, pH, acidity, acid load, flow rate, and the mine activity. Results show that acidity is 1600 mg / l, the acid load is 4423.68 kg / day, pH = 3.94 and the flow rate is 32 liters per second in this study. The DAOS method containing dosing with alkaline, oxidation by different methods which finally will be sediment is proposed for active treatment system.