Sampling and Washing of Gravel

The samples of the gravels can be done in two different ways:

• Taking half of the sample and mixing it before the rest of the material is extracted from the well.
• Through some holes done all down the extension of the well.

The washing of the samples that have been taken from the actual bed or in the actual well will be done with the pan or conic pan, with a sluice or with an instrument known as a Jig.

Pan or buddle washing
The washing of the samples is commonly done all through the sampling. In the case this were not possible, due to a lack of water, these will need to be placed in sacks and will be transported to a place, even artificial, where there is water and where it therefore can proceed to getting washed. As had been said before, as the samples go through a 5 mm in diameter sifter and what is left inside the sifter will need to be examined, in the case there are heavy material inside of it that can be seen or visible mineralization. What is left (less than 5 mm) needs to be washed from the mud making sure to always keep it in the pan. In the case of a Batea we understand that this is a recipient that has a conical shape to it that can be made out of metal and has the need of a pretty big surface of water. The instrument needs to float on the water and the gravel needs to turn with the rotating movement of the arms of the person handling it. By the centrifugal force of the lighter materials these will be slowly eliminated by the edges very slowly on the opposite end of the operator. When working in a water current, the evacuation of the lighter materials is done in the sense of the current. In order to make the flow of the light materials easier and to make the heavier ones fall down to the bottom of the pan, the pan needs to be shaken and or rotated horizontally and is something that an expert with a pan can do contemporaneously by rotating the pan. In the case what has been denominated as a Pan, it has a conical or round shape to it and can be made out of metal or plastic. The procedure for washing with this pan is exactly the same as it is with the batea with the difference that the evacuation of the lighter material is done by passing a coat of water over the surface, and only with horizontal shakes. The necessary amount of water is less and the operations can e carried out even over a canister, and there is the possibility of recovering and rewashing the obtained waste. When the amount of material that needs to be washed is a great amount, it is necessary to use a sluice or also an instrument that is known as the jig and from which there are several types, manual ones or by motor, but that essential work as dissymmetric separators.