Balance de agua y ajuste con multiplicadores de lagrange. Concentradora Laguna Seca, Minera Escondida

Abstract

Minera Escondida operated by BHP Billiton, is located in the Atacama desert at 3,100 meters above sea level, it is the mine with the highest production of fine copper in the world, reaching over one million metric tons of fine copper in 2017. These figures imply an important water consumption, a critical resource for the Escondida operation and mainly for its three concentrator plants. The purpose of this title report is to carry out the water balance for the Laguna Seca concentrator plants Línea 1 and Línea 2 belonging to Minera Escondida and to adjust it by applying Lagrange multipliers, for which it was necessary to execute the complete survey of the state of the instrumentation and of the data on the water flows of both concentrator plants, estimate the error of measurement of flows, update the nodal mesh of balance, calculation and reconciliation of the balance of solids, fine copper and water. For the case of Línea 1, the comparison between the results of the water balance with respect to the reconciled values shows an important addition of unquantified water in the flotation stage that reaches a value of 1,836,244 m3 of water during the month of the sampling, which is equivalent to a difference of 17.44% in the addition of total water and a proportion of 0.43 ð€¯ ð€°¯ ð€¯§ , while the Rougher tails reported a decrease in the volume of water by 1,295,216 m3 representing an adjustment of 15.22% over the monthly total, while the final tailings reported a decrease and 1,107,745 m3, equivalent to 9.58% of the total monthly value. The reconciliation of Línea 2 shows a decrease in water quantified in the Rougher feed of 120,554 m3, which represents a difference of 0.90% and a water ratio of 0.025 ð€¯ ð€°¯ ð€¯§ , while for the final tails there is a decrease of 455,391 m3 during the month of study, equivalent to an adjustment of 3.38% over the monthly total. The weighted consumption rate of Laguna Seca Línea 1 is 1.00 ð€¯ ð€°¯ ð€¯§ , a value that represents an overconsumption of 447.331 m3 over the reported value, however for Laguna Seca Línea 2, the weighted consumption rate is 0, 90 ð€¯ ð€°¯ ð€¯§ , meaning a surcharge of 157,764 m3. It is concluded that the greatest loss in efficiency in water consumption for both lines is due to the inadequate control in the addition of water from processes to the system, water that is mainly reported in the final tails, while the efficiency losses in The recovery of water is due to percentages of solids in the order of 49% and 50% in the discharge of tailings thickeners from Línea 1 and Línea 2 respectively.