Mirador Copper Mine is located in Zamora Chinchipe Province at the southeast end of Ecuador, the "Equatorial Country" in South America. The mining area is 340km south of the capital Quito, covering an area of 2985 hectares. It has 2.96 million tons of copper deposits, 3.22 million ounces of gold deposits and 26.08 million ounces of silver deposits.

The first overseas mine invested by Tongling Nonferrous Metals Group

Mirador Copper Mine is jointly built by Tongling Nonferrous Metals Group Corporation (hereinafter referred to as Tongling Nonferrous) and China Railway Construction Group Corporation. It is the first overseas resource development project of Tongling Nonferrous under the Belt and Road Initiative. This world-class open copper mine is invested, designed, constructed, manufactured and operated by China. It also sets a new record of the largest single overseas investment project in Anhui Province, and the first large-scale solid mine development project in Ecuador, which is listed as a national strategic project by Ecuador, and is called as the ” Presidential Project”.

The project phaseⅠ was put into operation on July 18, 2019, with a total investment of US $1.89 billion, and the designed annual ore processing capacity of 20 million tons, the daily ore processing capacity 60,000 tons, the annual copper concentrate output 354,000 tons and the copper metal capacity 96,000 tons. After reaching the design capacity, the self-sufficiency rate of the copper raw materials of Tongling Nonferrous can be increased to about 15%, which can effectively alleviate the shortage of copper concentrate produced by the Company. At the same time, the Mirador mine also generates about $100 million a year for the local economy, directly creates nearly 2,000 local jobs and indirectly benefits more than 10,000 people from the construction and development of the project.

Efficient operation with the sustainable grinding technology

The project phase Ⅰ of the Mirador mine has an annual design capaity of 20 million tonnes and is based on typical SABC process. The Concentrator consists of two parallel production lines, each with a processing capacity of 10 million tons per year. Two SUPERIOR® 60-110E MKII Gyratory Crushers are installed for primary crushing. The crushed ore is fed to the belt conveyor through AF Series Heavy Apron Feeders, and transported to the semi autogenous grinding stage. Where, the material discharged from SAG mill goes into LH™ Series Heavy Horizontal Screens, and the oversized is returned to Nordberg® HP500™ cone crushers respectively for pebble crushing. The Roughed copper concentrate regrinding system is equipped with two VTM-3000-WB Vertical Mills, with feed size of 80%-120 μm and the final grinding fineness of 80%-30 μm. The Concentrate filtration system is equipped with three VPA 1540-54 Filters for dewatering of the copper concentrate, with cake moisture contents 9%.

It is worth mentioning that the installed power of 3000 vertical mills in the Mine is 3000HP(2237kW), which is the largest vertical mill applied by the Chinese mining enterprises in the world so far. The mill features of high grinding efficiency, small footprint, low maintenance requirements, low media consumption and less lining wear, etc. Compared with the traditional ball mill, Metso Outotec vertical mill can save about 50% footprint, reduce energy consumption by about 40% and the media consumption by up to 50%, which can be widely used in applications of the primary and secondary stage grinding, regrinding, fine grinding and lime slaking.

The vertical grinding technology was originally developed in the 1950s. Metso Outotec successfully developed this technology in 1980 and first applied it to the large metal mines. During the last 40 years, we’ve installed more than 500 vertical mills worldwide, which is recognized by the industry as an energy efficient, green and sustainable grinding technology and solution.Editor/Zhao E