THE BOURSE WHISPERER: Orinoco Gold (ASX: OGX) announced results of metallurgical testwork at the company’s Cascavel gold project in Brazil.
Cascavel said the testwork, carried out by Gekko Systems, has confirmed the process flow-sheet for the Cascavel project.
Orinoco appointed Gekko Systems to construct a 15 tonne per hour gravity gold plant for Cascavel, for which Gekko Systems carried out various testwork programs on two samples of around 70 kilograms of Cascavel ore.
Gekko Systems reported results from the gravity test work program, which Orinoco claim to be at the upper end of results achieved for coarse gold deposits.
From a 70kg ore parcel, the Cascavel flowsheet achieved gravity gold recoveries of:
89.4 per cent gold recovery into 2.9 per cent of the mass at a grade of 417 grams per tonne gold;
91.6 per cent gold recovery into 5.9 per cent of the mass at a grade of 209 g/t gold; and
95.6 per cent gold recovery into 30 per cent of the mass at a grade of 43g/t gold.
“The results of the Gekko testwork program were both a pleasing endorsement of the company’s previous metallurgical testwork and a quantitative test justifying our development and production plan,” Orinoco Gold managing director Mark Papendieck said in the company’s announcement to the Australian Securities Exchange.
“One of the keys to the Cascavel investment proposition is the fact that we can achieve high gold recoveries from a modular gravity gold circuit which uses standard, simple gravity recovery with no chemicals or leaching.
“When combined with the fact that the gold is liberated without significant milling, this makes the process cost effective to purchase and install, and simple to operate.
“The Gekko testwork has not only reinforced previous results, but has in many respects, exceeded our expectations, demonstrating the ability to achieve excellent recoveries at a very coarse grind (p100 600μm) with a significant amount of the gold, around 88 to 89 per cent, being recovered in the first pass testwork at a grind size of (p100) 1.18 millimetres.
“This means that a coarse grind liberates most of the gold, which in turn shows that less energy is required to win the gold from the processing circuit.
“This bodes extremely well for the economics of the Cascavel project, which we expect to be a high-grade operation with low operating costs.”