Waste Rock Dump Geochemical Evolution: Matching Lab Data/Models and Predictions with Reality

摘要

The prediction of how waste materials will evolve geochemically within waste rock storage facilities (WRSF) has been the subject of many hundreds of thousands of hour's research by geoscientists globally. Despite the quantity of research there are two significant areas of uncertainty that remain as partially resolved issues: (a) the majority of the research carried out has been at the laboratory not site scale (b) many predictions made using computer modelling have not, or are not-normally able to be validated from site data.OKC has had the opportunity to lead two large scale WRSF drilling programs at different sites in Western Australia where 12 historical waste dumps of around 10-30 years in age have been subject to detailed intrusive investigation. This has included approximately 2,000 m of sonic drilling, the recovery and detailed analysis of over 2000 samples of core material and the installation of over 150 sensors at depths between 5-140 m within the waste which have provided over 5 million points of monitoring data.The extensive data gathered as part of the assessment has allowed OKC to determine the geochemical, hydrological and geophysical evolution of the waste rock facilities as a result of 10-30 years of exposure. This valuable site data has been used to both back test the results of predictive models made for the waste facilities, and to optimise predictive models for future scenarios. In addition the data has allowed the development of scaled up site specific kinetic leach columns.