Mining Technology 

About: Mining Technology is an academic journal. The journal publishes majorly in the area(s): Coal mining & Rock mass classification. Over the lifetime, 536 publications have been published receiving 5315 citations.

Moving forward from traditional optimization: grade uncertainty and risk effects in open-pit design

Abstract: An economic argument is presented for the incorporation of quantitative modelling of the uncertainty of grade, tonnage and geology into open-pit design and planning. Two new implementations of conditional simulation—the generalized sequential Gaussian simulation and direct block simulation—are outlined. An optimization study of a typical disseminated, low-grade, epithermal, quartz breccia-type gold deposit is used to highlight the differences between the financial projections that may be obtained from a single orebody model and the range of outcomes produced when, for example, fifty deposit simulations are run. The effects on expectations of net present value, production cost per ounce, mill feed grade and ore tonnage are presented as examples and periods with a high risk of negative discounted cash flow are identified. Further integration of uncertainty into optimization algorithms will be needed to increase their efficacy.

The Swebrec© function: linking fragmentation by blasting and crushing

Abstract: A new three-parameter fragment size distribution function has been found that links rock fragmentation by blasting and crushing. The new Swebrec © function gives excellent fits to hundreds of sets of sieved fragmentation data with correlation coefficients of 0·997 or better (r 2 >0·995) over a range of fragment sizes of 2‐3 orders of magnitude. A fiveparameter version reproduces sieved fragmentation curves all the way into the ‐100 µm range and also handles ball mill grinding data. In addition, the Swebrec © function: (i) can be used in the Kuz‐Ram model and removes two of its drawbacks ‐ the poor predictive capacity in the fines range and the upper limit cut-off to block sizes; (ii) reduces the JKMRC one-family description of crusher breakage functions based on the t 10 concept to a minimum; and (iii) establishes a new family of natural breakage characteristic (NBC) functions with a realistic shape that connects blast fragmentation and mechanical comminution and offers new insight into the working of the Steiner’s OCS sub-circuits of mechanical comminution. It is suggested that the extended Kuz‐Ram model, with the Swebrec © function replacing the Rosin‐Rammler function, be called the KCO model.

Stochastic optimisation model for open pit mine planning: application and risk analysis at copper deposit

Abstract: Life of mine (LOM) production scheduling is a critically important part of open pit mining ventures and deals with the efficient management of cash flows in the order of hundreds of millions of dollars. A LOM production schedule determines the quantity and quality of ore and waste materials to be mined over time, so as to maximise the net present value (NPV) of the mine. Life of mine production scheduling is an intricate and complex problem to address and it is adversely affected by geological risk, which can, however, be accounted for and managed while constructing production schedules. In the present study, the LOM scheduling process of a disseminated copper deposit demonstrates the intricacies of a new scheduling approach based on the technique of simulated annealing and stochastically simulated representations of the copper orebody. The study documents the benefits of incorporating geological uncertainty in the mine scheduling process through the proposed approach. The stochastic approach is f...

Stochastic integer programming for optimising long term production schedules of open pit mines: methods, application and value of stochastic solutions

Abstract: The production scheduling of open pit mines is an intricate, complex and difficult problem to address due to its large scale and the unavailability of a truly optimal net present value (NPV) solution, as well as the uncertainty in key parameters involved. These key factors are geological and mining, financial and environmental. Geological uncertainty is a major contributor in failing to meet production targets and the financial expectations of a project especially in the early stages of a project. Stochastic integer programming (SIP) models provide a framework for optimising mine production scheduling considering uncertainty. A specific SIP formulation is shown herein that generates the optimal production schedule using equally probable simulated orebody models as input, without averaging the related grades. The optimal production schedule is then the schedule that can produce the maximum achievable discounted total value from the project, given the available orebody uncertainty described through ...

Stochastic mine design optimisation based on simulated annealing: pit limits, production schedules, multiple orebody scenarios and sensitivity analysis

Abstract: Over recent years, new methods have been developed to integrate uncertainty into the optimisation of life-of-mine production planning. One of these methods is based on scheduling with a simulated annealing (SA) algorithm and equally probable realisations of a given mineral deposit. The latter realisations are used to generate production schedules that minimise the possibility of deviating from production targets, and result in schedules with a substantial improvement in the net present value (NPV), shown to be in the order of 25% when compared to conventional scheduling within the conventionally optimal pit limits. To facilitate the utilisation of this method, a sensitivity analysis is presented in this study. The study documents the case of a copper deposit where 10 simulated realisations are sufficient to provide stable life-of-mine optimisation results. In addition, the study shows that the selected true optimal pit limits are larger than those derived through conventional optimisation. Stochas...