An Incomplete Study of Gold Production from PR Tailings Incomplete insofar as I do not know know all of the processes but will assume what seems reasonable .
Individual layers in a tailings deposit, whether fine or coarse, are made up of mixtures of tailings sands of small particles and tailings slimes .
Tailings sands are shown to be almost pure silica quartz with approximately 10% illite.
Tailings slimes, on the other hand, contain considerable amounts of clay minerals and traces of pyrite and other sulphides in addition to the quartz.
Tailings, consequently, have a significant amount of clay fines, which can be expected to have a major effect on the mechanical behaviour of the material.
Clarified water and storm water is regularly pumped out of these tailings ponds to pen stocks leaving the clay - quartz exposed.
You can see this material on the website.
I have estimated previously that this slurry mixture contains about 30,000 ounces of gold fines.
Subsequent analyses of mine estimates that this is contained within about 750,000 tons of slimes .
This sediment slurry presumably has been pumped from the Tailings Pond into a stockpile adjacent to the mill.
I know that the slurry subsequent to tertiary treatment is being considered for agricultural material.
Taken together, this will constitute most of the tailings pond reclanmation.
What I don't know is how the mixture of quartz and slurry clay enters the mill.....as in situ ( heavy ) or
separated by gravity .
I assume the former as that is conservative .
The Pine Cove mill has an annual capscity of about 400,000 tons per year.
So, it would take about 2 years to process the tailings .
Throwing in about 5000 ounces from other stockpiles , over a 2 year period , approximately 15000 ounces per year can be produced from the raw tailings in Tailings Pond #2.
Thats quite decent amounting to about $50 million in annual revenues.
This is pretty paunchy rough ..it could be much higher if the slurry can be separated before processing ..or lower if the slurry complicates the processing rate.
Whatever, we are soon going to be exiting the low valued exploration phase into the much higher valued producer phase.
AIMHO
GLTA