The Importance of Sample Preparation in Mining

During the past few years, portable x-ray fluorescence (PXRF) analyzers have proven their performance in the field on hundreds of thousands of geological samples. In fact, the analytical performance using the latest handheld and field-portable analyzers in mining is now so good that the key limiting factor to receiving lab-quality results is adequate sample preparation – especially for the XRF analysis of elements lighter than calcium. So how can you ensure you are receiving the most accurate results when you are onsite? By preparing your sample. The analytical performance of XRF analysis on geological materials is significantly improved by collecting representative aliquots and proper preparation of the sample. Unfortunately, material with a particle size range of 100μm and below, which is necessary for high-performance lab-quality XRF analysis, cannot be practically achieved by any manual operation, so you must look to sample preparation equipment. There are two different types of equipment and methods for preparing your samples that I recommend: a direct rock sampler and an electric hammer mill. Both of these methods convert the sample into a fine powder so it can then become a pellet to be more accurately analyzed. I will compare the two methods in the next article, but right now I want to assure you that these very easy extra steps are certainly worth the effort. The above comparison charts illustrate results achieved with and without using the sample preparation tools. It shows that if you use proper sample preparation methods and tools, you will gather improved analysis results. Click here to see additional charts that show improved analysis results using XRF for both lighter and heavier elements, including: Magnesium (Mg), Nickel (Ni), and Iron (Fe). Download the mining sample prep tools specification sheet for more specifics.