Minera Florida Process Plant
Chile /
Libertador General Bernardo OHiggins /
Graneros /
World
/ Chile
/ Libertador General Bernardo OHiggins
/ Graneros
mine, production, mining
This is the processing facility for the ore which is mined from the Minera Florida Mine which is 100% owned by Yamana Gold.
The Alhué process plant (which is also referred as Alhué Plant) produces doré metal and zinc concentrate. Ore is hauled using 25-tonne trucks from the mine to a transfer point and from the transfer point to the process plant in 50-tonne haul trucks. At the process plant, the ore is crushed in three stages in closed circuit with vibrating screens. The final crushed product is 100% passing 10 mm and is delivered to one of two 600-tonne storage siloshead of the grinding circuit. The crushed ore is fed to two 3.7 m x 4.3 m ball mills where it is ground to a 65% passing 75 μm in closed circuit with a cyclone cluster. The cyclone overflow is then delivered to the flotation circuit that consists of eight 20 m3 flotation cells arranged in a rougher, scavenger, cleaner, and recleaner configuration. The bulk sulphide concentrate produced contains 22% Zn, approximately 105 g/t Au, and some silver (silver content varies with the head grade). The flotation plant recovers approximately 87% of the gold, 83% of the silver, and 80% of the zinc. The flotation plant tailings are pumped to the tailings facility.
The flotation bulk concentrate is thickened to 50% solids and leached with NaCN (sodium cyanide) solution in a series of ten 50 m3 leach tanks providing 72 hours of residence time. The products of the leaching circuit are a pregnant solution containing approximately 30 g/m3 Au and a thickened pulp containing the zinc sulphides. The leaching circuit recovers approximately 97% of the gold and 81% of the silver. The pregnant solution is clarified, heated, and then pumped to four electrowinning (EW) cells where gold and silver sludge is deposited on the cathodes. The sludge is periodically washed off, filtered, and dried prior to being smelted into doré metal in a furnace. The doré metal is cast into bars containing Au, Ag, and approximately 5% impurities (Cu, Pb, Zn). The EW circuit recovers approximately 98.5% of the gold and 99.5% of the silver.
After electrowinning, the barren solution is used to heat the incoming pregnant solution via the heat exchanger and is then sent to an INCO SO2/air cyanide destruction circuit. The water from the INCO circuit is reclaimed as process water and cyanide is precipitated as stable cyanate and iron-cyanide salts that are disposed of in an impoundment area. The thickener underflow containing the leached solids is filtered and stockpiled. The filtered solids are fed to the zinc flotation circuit at a rate of 3,000 tonnes per month. The zinc flotation circuit consists of ten 1.4 m3 mechanical flotation cells as roughers and scavengers followed by a 2 m diameter by 10 m high column cleaner cell. The final zinc concentrate contains approximately 56% to 60% Zn and the circuit recovers 70% to 77% of the zinc.
The Alhué process plant (which is also referred as Alhué Plant) produces doré metal and zinc concentrate. Ore is hauled using 25-tonne trucks from the mine to a transfer point and from the transfer point to the process plant in 50-tonne haul trucks. At the process plant, the ore is crushed in three stages in closed circuit with vibrating screens. The final crushed product is 100% passing 10 mm and is delivered to one of two 600-tonne storage siloshead of the grinding circuit. The crushed ore is fed to two 3.7 m x 4.3 m ball mills where it is ground to a 65% passing 75 μm in closed circuit with a cyclone cluster. The cyclone overflow is then delivered to the flotation circuit that consists of eight 20 m3 flotation cells arranged in a rougher, scavenger, cleaner, and recleaner configuration. The bulk sulphide concentrate produced contains 22% Zn, approximately 105 g/t Au, and some silver (silver content varies with the head grade). The flotation plant recovers approximately 87% of the gold, 83% of the silver, and 80% of the zinc. The flotation plant tailings are pumped to the tailings facility.
The flotation bulk concentrate is thickened to 50% solids and leached with NaCN (sodium cyanide) solution in a series of ten 50 m3 leach tanks providing 72 hours of residence time. The products of the leaching circuit are a pregnant solution containing approximately 30 g/m3 Au and a thickened pulp containing the zinc sulphides. The leaching circuit recovers approximately 97% of the gold and 81% of the silver. The pregnant solution is clarified, heated, and then pumped to four electrowinning (EW) cells where gold and silver sludge is deposited on the cathodes. The sludge is periodically washed off, filtered, and dried prior to being smelted into doré metal in a furnace. The doré metal is cast into bars containing Au, Ag, and approximately 5% impurities (Cu, Pb, Zn). The EW circuit recovers approximately 98.5% of the gold and 99.5% of the silver.
After electrowinning, the barren solution is used to heat the incoming pregnant solution via the heat exchanger and is then sent to an INCO SO2/air cyanide destruction circuit. The water from the INCO circuit is reclaimed as process water and cyanide is precipitated as stable cyanate and iron-cyanide salts that are disposed of in an impoundment area. The thickener underflow containing the leached solids is filtered and stockpiled. The filtered solids are fed to the zinc flotation circuit at a rate of 3,000 tonnes per month. The zinc flotation circuit consists of ten 1.4 m3 mechanical flotation cells as roughers and scavengers followed by a 2 m diameter by 10 m high column cleaner cell. The final zinc concentrate contains approximately 56% to 60% Zn and the circuit recovers 70% to 77% of the zinc.
Nearby cities:
Coordinates: 34°2'8"S 71°1'40"W