Milling Recoveries Of 86.6% For Gold And 84.1% For Silver 

RENO, NV - Allied Nevada Gold Corp. reported that is has received metallurgical test results from additional composite samples for its Hycroft mine located near Winnemucca, Nevada. The Company has included the new composite test results in a geologically representative metallurgical model, which includes all metallurgical test results received to date for milling oxide and sulfide mineralization. Based on the 39 composites included in the model, average recoveries, based on rock type and tonnage weighted, are expected to be 86.6% for gold and 84.1% for silver (compared with previous test work which indicated recoveries of 87.2% for gold and 81.7% for silver). Test work demonstrates that these recoveries may be achieved through a grind-flotation (to create a concentrate)-cyanidation of tailings circuit. Previous aqua regia test results indicate the flotation concentrate is very amenable to oxidation processes typically practiced within the industry, with recovery of 98.5% of the gold and 99.3% of the silver. Management believes that this metallurgical model provides a more accurate view of the metallurgical characteristics and recovery expectations at Hycroft. It is expected that, based on preliminary indications, gold and silver mill recoveries will improve with optimization of the metallurgical testing process.

"The metallurgical model is providing us with a good sense for what we should expect metallurgically from the various rock types on the property," commented Scott Caldwell, President & CEO. "While we understand that there remains a significant amount of work to be completed, these continued positive steps provide confidence as we move forward with the milling project feasibility study."

Currently, 46 additional composite samples are being metallurgically tested using the grinding-flotation of the sulfides to create a concentrate and cyanidation of the tailings flow sheet. This test work continues to provide data for the milling metallurgical model. Master composites will be constructed by domain for optimization test work. Five one thousand (1,000) kilogram bulk samples have been obtained for pilot plant testing simulating the proposed milling-flotation-tail cyanidation flow sheet. Flotation concentrate will be evaluated using various oxidation processes including roasting and autoclaving. Material from each bulk sample will be submitted for comminution and grindability test work. The size and geometry of this deposit allow the flexibility to blend mill feed for optimum metallurgical performance such as gold and silver grades, sulfide content and ore hardness. Management estimates that approximately 30% of the required metallurgical testing has been completed for a milling feasibility study, expected mid-2011. Due to the very large size of the current mineral resource and the scope of the milling scenario, management intends to conduct sulfide test work on a significant number of composite samples, distributed throughout the deposit. Management believes that this level of test work will allow for final flow sheet and plant design and that this test work will be completed by mid-2011. The goal of the sulfide metallurgical program is to provide information for the anticipated mill feasibility study, expected to be completed in the second half of 2011. All testing to date has been completed to a feasibility study standard.  Multi-element analysis conducted on 154 holes drilled at Hycroft indicates that only trace amounts of mercury exist below 150 meters, predominantly where the sulfide mineralization occurs. Current run-of-mine leach performance is consistent with historical gold recoveries of 56.6% and silver recoveries are averaging approximately 12% for a silver ounce to gold ounce production ratio of 2:1. The first crushing system became operational in the third quarter of 2010 and two additional crushers are expected to be added as more siliceous ore becomes available over the next 18 months. When combined with run-of-mine recoveries, crushing approximately 30% of the total current ore feed is expected to improve overall average recoveries to approximately 60% for gold and 14% for silver. The goal for oxide heap leach testing is to determine the optimum crush size for the oxide mineralization. Based upon the large size of the current oxide resource, management believes that additional column leach and grinding test work will be required on approximately 100 oxide composite samples. This test work is expected to be completed in the first half of 2011. The company's address is 9790 Gateway Drive, Suite 200, Reno, NV 89521, (775) 358-4455, fax: (775) 358 4458, email: [email protected].