Mining optimisation
A method, system and computer program for modelling an optimal mine plan is disclosed. The life of mine is divided into a plurality of increasing lengths of time (FIGS. 2 and 3 ) and performing optimisation steps, with each step being performed once for a predetermined time period for the remaining life of mine. Material may be stockpiled or may be sent direct to product or to waste without any stockpiling. A decision (block 10 in FIG. 1 ) is made as to which material is sent to product in each time period for the remaining life of mine. In each predetermined time period, material with a grade greater than a marginal grade that is not sent to produce is sent to stockpile and all material less than a marginal grade is sent to waste ( 14 ). In the remaining life of mine, after the predetermined period, it is required that all material not sent to produce be sent to waste and determining an initial movement of material to and from the stockpile and to and from the mine to product over the life of mine in increasing lengths of time.
1. A method of generating mine plan data for operation of a mine, comprising:
(a) obtaining mine data describing material in the mine which may be removed from the mine over a whole life of the mine;
(b) dividing, while a current remaining life of mine is longer than a defined time period, the current remaining life of mine into a plurality of time periods comprising a first time period and a plurality of subsequent time periods at least some of which are longer than the first time period such that the subsequent time periods tend to increase relative to the first time period;
(c) generating mine plan data for the current remaining life of mine by iterating through each of the plurality of time periods and
(i) determining for each of the plurality of time periods which material is to be extracted from the mine and which of that material is to be sent to product for the remaining life of mine;
(ii) determining for each of the plurality of time periods which material is less than a marginal grade and is to be sent to waste; and
(iii) requiring in each of the subsequent time periods, all material not sent to product be sent to waste;
(d) storing first time period data of the mine plan data generated in step (c);
(e) updating the current life of mine to begin after the first time period;
(f) repeating steps (b) to (e) for the whole life of mine; and
(g) concatenating the first time period data stored in each step (d) to form whole life of mine plan data describing planned material movements for the whole life of mine.
2. An apparatus for generating mine plan data for operation of a mine, the apparatus comprising a processor arranged to:
(a) receive mine data describing material in the mine which may be removed from a mine over a whole life of the mine;
(b) divide, while a current remaining life of mine is longer than a defined time period, the current remaining life of mine into a plurality of time periods comprising a first time period and a plurality of subsequent time periods at least some of which are longer than the first time period such that the subsequent time periods tend to increase relative to the first time period;
(c) generate mine plan data for the current remaining life of mine by iterating through each of the plurality of time periods and:
(i) determine for each of the plurality of time periods which material is to be extracted from the mine and which of that material is to be sent to product for the remaining life of mine;
(ii) determine for each of the plurality of time periods which material is less than a marginal grade and is to be sent to waste; and
(iii) require for the purpose of generating the mine plan data that in each of the subsequent time periods all material not sent to product be sent to waste
(d) store first time period data of the mine plan data generated in step (c);
(e) update the current life of mine to begin after the first time period;
(f) repeat steps (b) to (e) for the whole life of mine; and
(g) concatenate the first time period data stored in each step (d) to form whole life of mine plan data describing planned material movements for the whole life of mine.
3. The method of claim 1 comprising, in step (c), determining, for only the first time period, which material greater than a marginal grade but less than a product grade is to be sent to a stockpile.
4. The method of claim 3 , comprising, in iterations subsequent to a first occasion on which first time period data is stored, determining which material from the stockpile is to be combined with material extracted from the mine and sent to product.
5. The method of claim 1 , comprising updating the mine data describing the mine subsequent to each step (c) to reflect material extracted in the first time period such that each time steps (b) to (e) are repeated it is on the basis of updated mine data.
6. A method of mining comprising extracting material from a mine based on whole life of mine plan data produced in accordance with the method of claim 1 .
7. The apparatus of claim 2 arranged to determine, for only the first time period when generating mine plan data for the current remaining life of mine, which material greater than a marginal grade but less than a product grade is to be sent to a stockpile.
8. The apparatus of claim 7 , arranged to, in iterations subsequent to a first occasion on which first time period data is stored, determine which material from the stockpile is to be combined with material extracted from the mine and sent to product.
9. The apparatus of claim 2 arranged to update the mine data describing the mine subsequent to generating mine plan data for the current remaining life of mine to reflect material extracted in the first time period such that subsequent iterations are on the basis of updated mine data.