Mineral Sampling Error, Manual Sampling Analysis and Use of Jones Splitter

Abstract

Sampling technique errors differ from sampling error determination according to Gy. Metallurgical tests provide results that, when applied to operations, do not improve the process performance, so the question is where is error is. This article describes the evaluation of both manual and mechanical sampling techniques applied to different types of minerals. Most laboratories do not have proper equipment to reduce mineral mass, which is done with a Jones Splitter because of the small size of the sample. To avoid errors due to sampling changes, each group worked with the same mineral based on its granulometric distribution. The experiment considered different mineral samples like copper sulfides, zinc sulfides, Pb-Cu sulfides, Pb-Cu-Zn-Ag sulfides and gold minerals. There were 584 quartering processes divided as follows: 192 for manual reduction, 192 for the Jones divider, and 192 for checkerboard reduction. Every block was divided into 8 groups of 24 reductions each. The results showed that manual quartering has more errors compared to the use of a Jones spitter, but this in turn presents more errors than the checkerboard method. The manual quartering sampling had a 6.77% error compared to that of Jones with 4.87%. The Grubbs’ test was performed to identify the worst sample resulting in 5.91% for the manual reduction, 4.22% for the Jones divider, and 1.53% for the checkerboard method. The experiment proves that manual sampling is not the best technique to divide samples for metallurgic tests.