Rise Gold (CNSX:RISE) is still combing through the data it inherited when it purchased the Idaho-Maryland mine in California and has now been able to secure and analyze the historic production data at the mine, which was in production between 1866 and 1955.
According to this documentation, the total gold production at the I-M mine was approximately 2.4 million ounces of gold from ore with an average grade of 17.1 g/t. That being said, approximately 2/3rd of the total production came from the Idaho Mine, where the total average grade was 28.4 g/t, with the #1 vein having an average grade of 38.6 g/t which indeed is an average grade most (underground) mines can only dream of.
The documentation seems to be quite complete as Rise was also able to find the historic recovery rates from almost 100 years ago. In the 1924-1930 era, approximately 72-89% of the gold was recovered from the rock, which seems to confirm the thesis of Waldemar Lindgren who claimed the average recovery rate of the Grass Valley mines was approximately 75%. But as the historic operator of the I-M mine also treated the tailings by a secondary process, the recovery rate will very likely have been higher than this 75% and an 80% recovery rate might be more realistic (the company is assuming an average recovery rate of 85%).
However, later on, Rise was able to confirm the recovery rates increased substantially in the pre-war period (1936-1941), when the average recovery rate was in excess of 96% whilst processing ore with an average grade of half an ounce of gold per (short) tonne of rock (which translates into in excess of 17 g/t gold per metric tonne).
Meanwhile, Rise Gold is working hard to wrap everything up, and is still doing its due diligence on the acquisition on a 82 acres parcel of land, directly located to the Brunswick Mine shaft. If the 82 acre acquisition would be completed, Rise Gold will own 119 acres of land right around the shaft.
Rise Resources should almost be ready with combing through the documents, and we are looking forward to see the company’s plans to advance this property and perhaps restore the mine in its glory.