The Parral mining district is situated in the centre of the Mexican silver belt epithermal silver-gold vein districts. The geology of this belt is characterized by two volcanic sequences of Tertiary age, discordantly overlying deeply eroded Mesozoic sediments and older metamorphic rocks. The physiography of the belt resembles the basin and range area in the western USA, with wide, flat valleys and narrow, relatively low mountain ranges and hills.

The precious metal-bearing fissure vein type of mineral deposit is the most widespread and economically important type of deposit found in the belt. The belt has been recognized as a significant metallogenic province, which has reportedly produced more silver than any other equivalent area in the world.

Tailings from the Mina la Prieta mill were impounded on dry ground to the north of the mine and milling complex. The tailings were deposited over many years in flat, consistent layers, dewatered and eventually built up in 5 m lifts into raised heaps reaching a final height of 50 m. The physical consistency of the material is uniform and has an average particle size distribution of 80% passing 0.255 mm.

The Parral Project is a surface mining operation using conventional excavation equipment and on-road haulage trucks. The scale of production will require mining rates on the order of 5,200 t/d or 1.8 Mt/a of tailings. Waste handling quantities will be minimal.

The Plant is designed to process a minimum of 5,000 t/d. The extraction process is by conventional heap leach using sodium cyanide as the leaching reagent. Recovery of gold and silver from cyanide solution is by zinc precipitation. The very high silver content of the ore makes this process more cost effective than a carbon-in-leach or carbon-in-pulp process.

The Plant comprises of tailings reception with a temporary 40,000 tonnes re-mined tailings stockpile, an agglomeration and stacking circuit, a heap leach circuit, a Merrill-Crowe plant, a copper-acid leaching and precipitation circuit and neutralisation circuit.

SART project has been successfully installed and commissioned at Parral Tailings facility located in Chihuahua, Mexico. The SART plant is providing important economic and technical benefits to the Parral facility. The main economic drivers are the recovery of a high-grade saleable copper sulfide product, the re-generation of cyanide, which is the large ........