Abstract
Measurement while drilling (MWD) data are gathered during drilling operations and can provide information about the strength of the rock penetrated by the boreholes. In this paper MWD data from a marble open-pit operation in northern Norway are studied. The rock types are represented by discrete classes, and the data is then modeled by a hidden Markov model (HMM). Results of using different MWD data variables are studied and presented. These results are compared and co-interpreted with optical televiewer (OTV) images, magnetic susceptibility and spectral gamma values collected in the borehole using down-the-hole sensors. A model with penetration rate, rotation pressure and dampening pressure data show a good visual correlation with OTV image for the studied boreholes. The marble class is characterized by medium penetration rate and medium rotation pressure, whereas the intrusions are characterized by low penetration rate and medium to high rotation pressure. The fractured marble is characterized by high penetration rate, high rotation and low dampening pressure. Future research will use the presented results to develop a heterogeneity index, develop an MWD-based 3D-geology model and an improved sampling strategy and investigate how to implement this in the mine planning process and reconciliation.
Highlights
This paper is part of a research project focusing on the implementation of geometallurgical concepts in the industrial mineral sector of the Norwegian mining industry
The data are gathered in an interval of approximately every 2 cm. In addition to these Measurement While Drilling (MWD) data, which are available in all boreholes, an optical tele-viewer image (OTV), magnetic susceptibility (MSUS), spectral gamma (SGAM) and total gamma (TGAM) are logged for some boreholes
A new method to classify rock types according to its rock strength and hardness, especially hard rock intrusions in a marble deposit, using MWD data collected during normal bench drilling is proposed
Summary
This paper is part of a research project focusing on the implementation of geometallurgical concepts in the industrial mineral sector of the Norwegian mining industry. A geometallurgical model is a combination of geological and mineral processing information into a spatial and predictive tool to be used in production planning and management in the mining industry [1]. These kinds of predictive models aim at taking grade into account when estimating key performance indicators (KPIs), and parameters related to for example micro-scale texture information or strength and hardness variations. Strength is a material parameter quantifying a material’s ability to withstand an applied force without expressing plastic deformation. The deposit consists of different types of marble formation and they are informally named “speckled-”,
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
