I think the whatchamacallit takes the dohickey stuff and sticks it in the thingamagig and then the yellow stuff comes out. Sorry, but that's all I know.
If you haven't seen this reprint of GE in Bolivia’s premiere resource and mining magazine, Energy, Mining and Construction, it's got some great info.
geii.com
Over the next two years, to that metallurgical work Dr. Atwood and Dr. Viscarra added studies and observations on the behavior of the conglomerate material and found that it would subside to one draw point opened at the end of a number of lateral workings for the purpose of mining using “conal subsidence”, which has been characterized as a form of block caving without the need of expensive interior mine infrastructure to cut the ore block. By designing a mining method that pushes an adit under the ore and allows the ore to subside to various draw points built with reinforced concrete at the end of lateral drifts, Dr. Atwood created an ingenious, inexpensive mine plan that would take advantage of the mountainous terrain formed by the conglomerate. Effectively, each draw point would be extracting ore from a vertical column cutting across several highly mineralized pay streaks as well as the lower grade material between the pay streaks, for a higher average grade.
In a fortuitous turn of events, and after years of lobbying, the high power distribution network installed a 25-megawatt line directly over the entire length of Golden Eagle’s property. Through the use of electrically powered conveyors for ore haulage and tailing impoundment, in addition to all ore processing, the company was able to project extremely low costs per ton of ore mined. Using an average target grade of 0.25 grams (0.008 troy ounces) of gold per ton of ore mined, which is well below the grades estimated in all of the combined sampling, Dr. Atwood estimated a very low cost per ounce of gold produced of less than $75. The key factors in the operation are high volume earth movement (11,000 tons per day); inexpensive electricity for ore haulage, tailings impoundment, and processing; an inexpensive, well qualified labor force; and recoveries of free gold in the range of 95% due to a flow sheet that effectively separates the clays and recovers fine gold into the –10 micron range. |
