Mechanized Methods of Sampling

Churn drill perforations. This method consists of the drilling by percussion with casing done with mechanized equipment to obtain a crushed sample. The sample, in most cases, is obtained by intervals of 25 cm of advancement; this varies according to the characteristics of the material of the deposit (such as if it is thick or fine gravel etc) which influences on the rising of the material, whether this be due to excess or defect. Once the perforating machine has been installed, perforation begins with the location of the shoe casing, which is introduced through hammering, first until a depth of 1.00 meters with the object of obtaining stability. Right after, through the usage of the chisel, the breaking of the crushing of the gravel that has gone inside of the tube is carried out; after achieving the desired depth the hammer and chisel is taken out.

With the adequate addition of water when it is necessary, the operation of pumping to a reception canal that is inclined that flows to a cylinder recipient where the capacity is regulated in lineal meters, where the volume of the extracted sample is measured with a graduating ruler. The pumping consists in introducing through the gravity of the pump down until the end of the drill, and then when extracting the loaded pump, the check valve closes. Finally the ground sample will need to be panned with the material with the material of the barrel of lama, to carry out the counting of the gold particles that are present in the sand in a clarifying pan and finally registering the geo mineralogical characteristics of the alluvial placer.

Determination of the mineral reserves
The mineral reserves in the placer deposits are in most cases classifying in: economic channel, explored channel and prospective channel. The most widely utilized methods of calculus for the cubage of mineral reserves can be graphic methods, inside of these the method of sections by area of influence, blockage method by triangles and by polygons. And the statistic methods.