The draw control strategies in Table III are assessed the based on 10 factors. Sampling and assay system: In these situations, LHDs can load directly onto trucks but this reduces productivity. Australasian Institute of Mining and Metallurgy, Melbourne. Guidelines for designing a new draw control strategy. Gustafson I ; P. The marker trials have provided important knowledge on flow behaviour and dilution behaviour and have been used for mine design and ore flow simulation in SLC mines.
Kiirunavaara mine is the largest underground iron ore operation in the world. The impact of blasting on sublevel caving material flow behaviour and recovery. Malmberget has three loading criteria. The assessment shows that traditional draw control strategy, dilution entry method, and non-dilution methods are not recommended for draw control purposes. Such a model could aim at grade forecasting at the drawpoint and assist in evaluating the economic performance of the drawpoint. Careful assessment of dilution behaviour: The recovery of each cell is calculated based on Equation :
Marker trials have shown that secondary and tertiary recovery play an important role in ore recovery. If thess is no development at the lower level or in case of complete development at the lower level, a production ring can be blasted and loaded.
All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License. Hence, the mine currently has between 18 and 25 active drawpoints.
If the operator is unable to release the hangup, it is inspected and classified as a high hang-up or a low hang-up. The last rings drilled in the production drifts have their drill collars in the footwall, resulting in internal dilution.
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Malmberget mine consists of about 20 orebodies, 12 of which are currently being mined. Sublevel cave practices at the Frood-Stobie Complex. Shekhar I ; A. A review of sub-level caving practices in Canada. A 3D cone is mmaster to select the cells to be used for building weights, as shown in Figure 3. Mining blocks with structurally unstable areas thessi prioritized for blasting and loading.
The final output is a block model containing both in-situ grade and diluted grade for all blocks based on planned extraction ratios for each ring on each level. The Kiirunavaara mine produced around In this model, the values of model coefficients A, B, and C from Equation  are used to optimize the planned extraction ratio for all remaining production rings.
In this method, loading should be stopped as soon as dilution is encountered at the drawpoint Zhigui and Xingguo, The initial inflow of waste is neglected, and extraction ratio targets for these rings are kept higher to recover ore that may have accumulated in the upper part of the rings.
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In these situations, LHDs can load directly onto trucks but this reduces productivity. Laboratories were set up close to the centres of production, returning assay results within half an hour of sampling using standard sample preparation equipment thessi a portable isotope fluorescent X-ray analyser Hancock and Mattson, Modeling granular flow in caving mines: Mawter the future, the mine plans to drill and blast the ring but not load the material.
As mines generally have machines llkab different bucket sizes, the WOLIS system uses different X and Y values stored for the different machines. The loading criterion In the Kiirunavaara mine is the extraction ratio, which is the ratio of the total tonnage of material loaded from the drawpoint to the estimated tonnage of the ring.
Smith and Rahal state that draw control incorporates the sequencing and scheduling of development, production, and the material handling system, with the dual and contradictory objectives of minimizing mining masteer and dilution. Monitoring the drawpoint in SLC The monitoring of the ore grade at the drawpoint is termed ‘grade control’ Booth et al.
Visual grade control techniques and sub-level cave draw optimisation – Perseverance Nickel Mine, Leinster, Western Australia.
The mine also has constraints based on vibration levels in the nearby city of Kiruna, but this is not a source of concern for the mine itself. Australasian Institute of Mining and Metallurgy, Melbourne.
Journal of Quality in Maintenance Engineering, vol. The curves are used to complement mine planning and scheduling. However, certain assumptions, for example assuming low extraction ratios in upper levels will translate into more ore at levels below, should not be made because of the chaotic nature of the thesos flow.
Draw bin method Naster draw bin method was first ljab in a feasibility study at Telfer mine, Australia, and then used at Ridgeway Deeps, Australia Allman,in Jamieson, Production rings with a very high percentage of waste intrusion visualized in the WOLIS system are not drilled but left intact.
Guidelines for designing a new draw control strategy. This weight measurement system is called the Loadrite scoop weighing system. Production and maintenance performance analysis: