Prediction of acid rock drainage potential using XRF/XRT drill core scanning

Purpose and goal:

Diamond drill cores of varying mineralization were scanned with XRF/XRT to determine if the technique can estimate acid generation. The XRF analyzes from the scans agree well with the reference sulfur analyses. When interpreting the acid-generating minerals from X-rays, the sulfides were underestimated.

Even the buffering minerals were difficult to estimate, as the attenuation is low. The scans showed good agreement with the total sulfur levels, while identification of the acid-forming and buffering minerals needs further calibration to be used accurately. Expected results and effects:

XRF analyzes showed good agreement with respect to total sulfur concentrations, while the X-ray analyzes underestimated the presence of specifically acid-generating minerals. X-rays also had difficulty identifying the specifically participating buffering minerals in the samples. Based on the results, however, the technique is judged to be a feasible route for assessment of potential acid generation after further calibration and calculations.

Approach and implementation:

The feasibility study has been delayed as a result of the project manager changing position (to Head of School) and having less time for own research. The practical implementation has gone according to plan with scanning of drill cores and analysis of a selection of samples with regard to reference analyzes (wet chemistry and NAG). The low attenuation of the light elements in the buffering minerals has made it difficult to estimate the true buffering capacity of the samples.

Further detailed studies will be carried out after the end of the project to try to solve that calibration problem.