Sun Silver (ASX:SS1) said average silver recoveries reached 77% while average gold recoveries were 74% under early-stage heap leach test conditions at the Maverick Springs Silver-Gold Project in the US, according to a Thursday Australian bourse filing.

The company said cyanide leach tests, which provide an estimate of a fine grind tank leach, achieved silver recoveries of up to 90%, averaging 87.25%, while gold recoveries reached up to 84.7%, averaging 82.15%.

Reducing chlorides in process water via reverse osmosis presents a potential opportunity to further enhance recoveries at Maverick Springs, the filing added.

The company's shares rose about 3% in recent Thursday trade.