To: Richard Mazzarella who wrote (8499 ) 11/12/1998 9:45:00 PM From: Tim Hall Read Replies (1) | Respond to of 14226
Richard, Being somewhat familiar with stockpiles, I have serious doubts about the consistency of the pile. If this pile was created by a contractor providing construction materials for a highway project, there are probably two methods that were used to construct the pile. The first would be with a stacking conveyor. This would involve building a cone and as the top of the pile reached the conveyor discharge, the conveyor would be moved in a radial manner. This would result in two methods for segregation. The material mined first would be in the first part of the pile and the material mined last would be in a different part of the pile. If they mined through paleo channels such as Maxam has identified, the pile would be inconsistent. When building a conical stockpile, the coarser material tends to run to the sides and the finer material stays in the center. This would result in segregation throughout the pile. The second method for building the pile would be with trucks. Here again, depending on the precise pattern the trucks used and where the material was mined, you could have 12 to 15 ton pods throughout the pile. Material dumped from trucks also tends to segregate the fines from the coarse material. I produce a product that contains material from 50 mesh to 200 mesh. When I place this material into a 250 ton silo, it segregates. In order to stop the segregation, we put the material in at 8 points at the top of the bin and remove it in the same way at the bottom. This phenomena could also explain why GPGI gets inconsistent assay and recovery results. Tim Hall