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"From April 22 to 28, the eyes of the tunneling and underground construction world will be on San Francisco, CA, as the world’s most influential underground construction industry leaders gather at the Moscone Center for the 2016 World Tunnel Congress.Recognized as the most important international annual meeting for the industry, the 2016 version comes to the United States for the first time in 20 years and will be hosted by the Underground Construction Association of SME (UCA of SME). The conference will be held in lieu of the UCA’s biennial North American Tunneling Conference and will bring the strengths and resources of the UCA of SME and the International Tunnelling and Underground Space Association (ITA). The result will be a conference with unmatched technical programming and a showcase of more than 200 exhibiting companies.A program committee led by Randy Essex of Mott MacDonald, Lonnie Jacobs of Frontier Kemper Constructors, Michael Mooney, of the Colorado School of Mines, Priscilla Nelson, of the Colorado School of Mines and Amanda Elioff of Parsons Brinkerhoff formed the program committee and worked for more than two years to build the program. The result is four technical sessions with five tracks in each session and 185 oral presentations.“One challenge was the sheer size of the group that would be assembled, perhaps 2,500 attendees or more, and the large number of abstracts we were likely to receive,” said Essex. “ We investigated extending the conference a fourth day, but that was not workable with the Moscone Center. We settled on having five concurrent technical tracks – something that has not been attempted in past NAT or RETC conferences to my knowledge. The next step was to develop suggested session titles that would span the breadth of subjects that would interest conference attendees as well as serve the conference theme.”"

Apr 1, 2016

By Stephen M. Smading

The Jinping-II hydroelectric project in China features four parallel headrace tunnels approximately 18-km- (11-mile-) long. Two will be excavated by tunnel boring machines (TBM) and two by drill-and-blast. A nearby fifth tunnel is being excavated by a 7.2-m (23.6-ft) TBM to draw down ground water in advance of excavating the headrace tunnels. Unique onsite assembly of a 12.43-m (40.7-ft) main beam TBM and backup system was completed on Sept. 18, 2008 in the remote mountains of the Sichuan province. The equipment was assembled onsite, without previously having been assembled and tested in a factory, using a method called onsite first time assembly (OFTA). This paper addresses the following topics: ? Project description including geology and terrain. ? The decision process leading to onsite, first time assembly, the assembly process and logistics, and lessons learned. ? Design features of the TBM and backup system. ? Operational history from startup to the writing of this article.

Jan 1, 2009

By R. T. Jones

"Technical publications in the field of mining and metallurgy have existed for a long time. Recent developments in electronic publishing on websites make it possible to disseminate information more widely and cost effectively than before. Professional societies have an opportunity to serve their members and their industry by publishing high-quality peer-reviewed papers on their websites as well as in printed form. Older publications can be scanned, and optical character recognition can be used to provide searchable text. Various business models exist around this process. This paper outlines the approach used by the Southern African Institute of Mining and Metallurgy (SAIMM) to provide free open access to their journal papers and conference proceedings, as well as the work being done by OneMine.org to collect technical papers from a number of international societies and make them available to subscribers via a large database. An approach is outlined that should be of benefit to authors, readers, and society at large.INTRODUCTIONGeorgius Agricola (1494-1555) was not the first writer on the subjects of mining and metallurgy, but is well known as the author of De Re Metallica (‘of things metallic’ or ‘on the nature of metals’), a book that documents and illustrates the observations he made in the course of his extensive travels in the 1500s. Agricola wrote extensively about mining methods and metallurgical processes that were in place in the Middle Ages. The original Latin version of De Re Metallica was published in 1556, the year after Agricola died. It was translated into English by Herbert Hoover, a mining engineer and later President of the United States, and his wife Lou Henry Hoover, a geologist and classicist. The English version of De Re Metallica was published in 1912."

Jan 1, 2012

By C Rizos

Many of the ‘new paradigms in mining’ and notions of ‘sustainable mining’ have at their core the requirement for reliable, continuous centimetre-level positioning accuracy to enable increased automation of mining operations. The deployment of precision systems for navigating, controlling and monitoring machinery such as drills, dozers, draglines and shovels with real time position information increase their operational efficiency, and reduce the need for humans to be exposed to hazardous conditions. The Global Positioning System (GPS) is the best known, and only currently fully operational, Global Navigation Satellite System (GNSS) providing positioning capability anywhere in the globe, on a continuous 24/7 basis, with accuracies ranging from the dekametre-level to the sub-centimetre-level depending on hardware and operational configuration. Despite this versatility, GNSS cannot satisfy the high accuracy positioning requirements for many applications in mine surveying, and mine machine guidance and control. The reason is that increasingly open cut mines are getting deeper, resulting in a reduction of the ‘sky-view’ necessary for GNSS systems to operate satisfactorily. Yet, to date there have been no viable alternatives to GNSS that can be deployed in mine environments that can meet the challenging requirements in open cut mines.Locata Corporation, a Canberra-based company, has invented a terrestrial high accuracy positioning system known as ‘Locata’ that can augment GNSS with extra terrestrial signals to permit cm-level positioning accuracy even when there are insufficient GNSS satellite signals for reliable positioning and navigation. Locata relies on a network of synchronised ground-based transceivers that transmit positioning signals that can be tracked by suitably equipped user receivers. Hence Locata can be considered a new type of ‘local constellation’, able to provide high accuracy positioning coverage where GNSS fails. This paper introduces some of the technical aspects of this Australian technology and describes tests conducted by Leica Geosystems over the last few years at Newmont Boddington Gold in Western Australia. A recent news announcement by Leica Geosystems (12 January 2011) has confirmed that their new mine management system will have combined GNSS + Locata positioning capability – the first commercial product that integrates GNSS and Locata capabilities into a single high accuracy and high availability navigation device for open cut mine machine automation applications.

Nov 22, 2011

The Pilbara region, located in the north-west of Western Australia, is significant as the second-largest source of iron ore on the planet. Iron ore mines owned and operated by Pilbara Iron are located within the Hamersley Basin. This paper refers to the Greater Paraburdoo mines, the 4WEST and 4EAST pits, located on the southern margin of the Hamersley Basin. The groundwater model refers to ephemeral watercourses: Seven Mile and Pirraburdoo creeks, which are adjacent to the two pits, and Ratty Springs, located upstream from 4WEST and within Pirraburdoo creek. The spring and creeks hold cultural heritage significance for local Aboriginal communities. Two of these, the Gobawarrah Minduarra Yinhawanga (GMY) and Innawonga native title claim groups, initiated hydrological work on the two creeks and Ratty Springs, with the aim of determining the affects of dewatering on the natural water flows of these systems. The numerical model used to simulate drawdown in the Pirraburdoo and Seven Mile Creeks was derived from PMWIN Pro software and covered an area of 77 km2. The modelling period was from January 1998 to December 2004, and the prediction period was from January 2005 to December 2015. The model has four layers and incorporated effects caused by mining voids, 4WEST and 4EAST pits, creek bed material, weathered bedrock below creeks and surrounding banded iron formations (BIF). The model has been calibrated using the trial-and-error method set down by Middelmis et al (2001). The current dewatering schedule (12 ML/day) in the 4WEST and 4EAST mining areas does not affect the water table levels in the adjacent creeks significantly or for any considerable periods of time. However, changes to mine plans may occur, for example, in response to changed commodity price and may lead to significant increase in rates of vertical advancement. This, in turn, affects dewatering schedules, as greater vertical advancement requires increased dewatering effort. When an accelerated mine plan is applied to the model and dewatering rates increased to 18 ML/day, drawdowns in the creeks are more noticeable. The model has therefore helped to indicate the extent to which increased dewatering rates may be acceptable, especially in terms of immediate and longer-term damage to riparian species, ie Melaleuca and Eucalypt. Predictions from the model may also allow mine planners to schedule decreased rates of vertical advancement, where these are required to meet environmental constraints.

Jan 1, 2006

By James B. Cathcart

The potash mine of the International Minerals and Chemical Corp. is about 18 miles east of Carlsbad, New Mexico, in sec 1 and 12, T 22 S, R 29 E, N.M.P.M. Potash is produced from two zones in the Salado formation of late Permian age. The lower zone, consisting of a mixture of sylvite (KCl) and halite (NaCl), lies at a depth of about 900 ft, and the upper zone, in which the principal potassium mineral is langbeinite (K2S04.2MgS0d), lies at a depth of about 800 ft. Because of the plastic nature of the material, fractures in the Salado formation are extremely rare and have been noted only on the 800 ft level of the International mine. The open fracture described below is almost unique. Only one other open fracture has been noted, and it was on a working face in the same general area as the one described, but was destroyed before the writer had a chance to examine it. According to J. E. Tong, foreman on the 800 level, this fracture was similar to, but smaller than, the one herein described.

Jan 1, 1949

By Keith Whitworth

The USSR, over the last 20 years, has continued to increase its out-put year by year and it is now almost four times what it was at the end of the Second World War. In 1975, it exceeded 700 million tons of run-oi-mine coal (all ranks) which amounts to over 20 percent of world output. This rapid progress has been due to modernization of the industry, by means of increased mechanization and automation and the development of new machines and systems for underground workings and by the expansion of open-pit workings and the development and implementation of larger earthmoving machines.

Jan 1, 1977

The purpose of this paper is to present the methods used in ground water control and the considerations that affected the development of these techniques. Production at Knob Lake is currently proceeding at depths which may be as much as 200 feet below the original standing water table. In order to produce a more saleable product and to improve operating and maintenance conditions, it is necessary to depress the water table below the mining level. Considerable success has been achieved by drilling deep wells in strategic locations and installing vertical tur-bine pumps at depths of up to 400 feet. This method is especially suitable for operation under severe winter conditions and has reduced the detrimental effects by a far greater extent than other methods of water control, Spring runoff is handled in open sumps, but all other water from four mines, with flows exceeding 16,000 g.p.m., is pumped all year 'round from about thirty-five wells. THE Knob Lake operation of the. Iron Ore Company of Canada is located on the Quebec-Labrador border, 320 miles north of Sept-lies, a seaport

Jan 1, 1965

The purpose of this paper is to present the methods used in ground water control and the considerations that affected the development of these techniques. Production at Knob Lake is currently proceeding at depths which may be as much as 200 feet below the original standing water table. In order to produce a more saleable product and to improve operating and maintenance conditions, it is necessary to depress the water table below the mining level. Considerable success has been achieved by drilling deep wells in strategic locations and installing vertical tur-bine pumps at depths of up to 400 feet. This method is especially suitable for operation under severe winter conditions and has reduced the detrimental effects by a far greater extent than other methods of water control, Spring runoff is handled in open sumps, but all other water from four mines, with flows exceeding 16,000 g.p.m., is pumped all year 'round from about thirty-five wells. T HE Knob Lake operation of the. Iron Ore Company of Canada is located on the Quebec-Labrador border, 320 miles north of Sept Iles,

Jan 1, 1965

By M. Deutsch

A common casualty of modern open pit mine optimization is the assurance that the resulting design is actually achievable. Optimized mine plans that consider value and a bare minimum of precedence constraints do not, in general, translate into practical, operational mine designs that can really be used in the field. Ultimate pits may come to a sharp point at the bottom. Schedules may require taking small parcels of material from many disparate areas of the pit in a single period. And grade control polygons may be ragged, narrow, and not minable with realistic equipment. In this paper all of these problems are addressed by encoding these three fundamental open pit mine optimization problems as maximum satisfiability problems. Maximum satisfiability provides a useful framework for problems that are non-linear and may guarantee the optimality that metaheuristics cannot. INTRODUCTION Open pit mines are large and complicated operations, which require significant initial and ongoing investment. A single mine may employ hundreds or thousands of people and creates substantial benefits for both the surrounding and global communities. Planning an operation of this magnitude requires a lot of effort and cannot be done optimally by hand. Mining engineers today rely on many techniques from operations research to guide decision making, and to maximize the value of the mine. Techniques including linear programming, metaheuristics, and network algorithms are all used to solve different problems throughout mine design and optimization. However, techniques based on Boolean satisfiability, including the optimization extension of maximum satisfiability, have not seen much use in mining despite being used in many other fields including electronics design, scheduling, and artificial intelligence. We claim that maximum satisfiability is a useful and meaningful way of expressing and solving optimization problems in mine planning. However, this technique does not come without challenges; the problem is NP-hard, and modern techniques for solving these problems can struggle with the number of variables and clauses that a typical mining problem requires. Also, some of the constraints that mining must contend with do not fit nicely into the satisfiability paradigm. Despite these challenges, we believe that maximum satisfiability provides a useful framework for considering operational constraints and expressing some problems that other techniques can't easily express. Maximum satisfiability can be solved exactly, yielding the true optimal answer which metaheuristics cannot guarantee. In this paper we show the applicability of maximum satisfiability to mining by specifying three fundamental problems in open pit mine optimization. We show how these fundamental problems can be formulated and how they can be extended within the framework of maximum satisfiability. For the remainder of the paper we first give a brief background on common elements between the three problems and an introduction to satisfiability. Then we tackle the three problems; the Ultimate Pit Problem, the Block Scheduling Problem, and the Grade Control Polygon Problem. In the Ultimate Pit Problem we specifically show how to extend the problem to support a minimum mining width – a coveted result for many mining engineers. We then discuss some of the complexities and shortcomings of this framework and possible research directions.

Jan 1, 2019

By Sabry A. Sabour

Metal price is among the key variables in the open pit optimization and the economic evaluation process. The common approach to handle metal prices in open pit mine planning is to optimize the ultimate pit and the mining schedules using a fixed, flat metal price. In this respect, metal price is assumed to be known with certainty throughout the entire mine life, which in some cases can reach 80 years. Given the volatile nature of metal markets and the metal price cycles, the conventional pit optimization approach may generate sub-optimized mining plans, which results in either extra costs to mining projects or lost revenues, or both. Long-term operational decisions such as future pit expansions, beyond the currently optimized limits, cannot be handled using the pit optimization approach based on flat metal prices. There is a growing interest in the mining industry to model and manage such market uncertainty in the pit optimization as well as the project evaluations in order to maximize the value of mining operations. In this paper, the author will outline a practical approach to optimize the ultimate pit taking into account the volatility and variability of metal markets. The proposed approach uses a combination of the pit optimizer of the commercial MineSight package and a simulation-based economic modeling real options valuation approach employing the least-squares Monte Carlo algorithm. MineSight pit optimizer employs both the floating cone for initial optimization exercise and the standard Lerchs-Grossmann algorithm. In this paper, Lerchs-Grossmann option will be used to generate the pit shells. Real options valuation approach used in this study is based on generating multiple metal price scenarios. Metal price uncertainty is modeled using stochastic metal price models such as the geometric Brownian motion and the mean-reverting process. The mining operational scenarios corresponding to the simulated metal prices are then optimized using the least-square Monte Carlo approach. The objective is to maximize the discounted cash flow value of the project while incorporating the operating flexibility to revise the operating status of the open pit with time as new information becomes available. The focus of this work is on the practicality of the proposed uncertainty-based pit optimization approach and the difference it can make to the technical operational mining decisions. A case study of a hypothetical open pit poly-metallic mine is provided. The deposit contains copper, gold and silver grades. The run of mine ore is sent to the process plant that produces copper concentrate with copper as the main metal and gold and silver as the by-products. Four uncertain variables are considered here include copper, gold, silver prices and foreign exchange rate. Both copper price and exchange rate are modeled using the mean-reverting process while gold and silver prices are modeled using the geometric Brownian motion. The case study is performed using both the conventional flat price pit optimization approach and the proposed uncertainty-based one to compare results.

Aug 1, 2013

By Biswajit Samanta, Rahul Kumar, Pranjal Pathak

The Open Pit Mine Production Scheduling Problem (OPMPSP) is a complex optimization problem that seeks to determine the best sequence for extracting mineralized material from the ground in order to maximize the Net Present Value (NPV). This process must take into account various capacity constraints, such as mining rates, processing limits, stockpiling capacities, blending requirements, and precedence constraints, which dictate the order in which blocks can be extracted. Traditionally, the OPMPSP has been formulated as a mixed integer programming problem, employing binary and continuous variables to represent the extraction of each block. However, this approach has limitations, particularly when it comes to addressing the stockpiling issue. In response, some researchers have proposed mathematical models, which offer a more accurate representation of the problem but come with their own set of challenges. In this study, an alternative approach to tackle the OPMPSP with stockpiling by employing constraint programming (CP) is explored. The method was carefully tested on the Newman1 dataset from the well-known Minelib library. The results show that the CP-based model obtained a production schedule having about 2.69 % higher NPV than the NPV of the solution, which is recorded in the Minelib Library.

Jun 25, 2023

By M. T. Smith

In a 2,000 square mile area of Polk, Hillsborough, Hardee and Manatee Counties in Central Florida is located one of the richest known deposits of the life-giving mineral, phosphorus. Under layers of sand and clay are found millions of tons of phosphate rock, best source of this element which is necessary to all forms of life - plant, animal and human. Phosphorus is an irreplaceable ingredient in all complete plant foods, and more than 90% of Florida's vast production goes to enrich the croplands of the United States and many other areas of a hungry world. In addition to this, it has wide industrial use in the manufacture of many products - detergents, baking powder, carbonated beverages, steel, matches, munitions, glass, insecticides, dyes, water softeners and innumerable others. Not only does phosphorus make life possible for us - it also helps us to live longer and better.

Jan 1, 1962

By P. L. Russell

The use of nuclear explosives for excavation has been demonstrated to be feasible and practical. Application of nuclear explosives for overburden removal from large ore deposits appears to offer economic advantages over present methods, but under the present pricing schedule, high-yield devices must be used to obtain an economic advantage. The use of nuclear explosives presents problems not inherent in the use of conventional explosives, and thus they can be used only in areas where large explosions and associated phenomena can be tolerated. Stripping of coal with nuclear explosives does not appear practical at this time, but stripping overburden from copper or iron ore deposits may be a potential use. Even here, however, the use of nuclear explosives would require isolation, favorable topography, favorable ground-water conditions, and a low population density. If these basic requirements can be met, the use of nuclear explosives for overburden removal would offer both economic and time advantages. The possibility of using nuclear explosives for peaceful purposes was a subject for speculation as early as 1945. The PLOWSHARE Program was formally established by the AEC in June 1957 for the purpose of developing and demonstrating peaceful applications for nuclear explosives. The technical direction of the program is the responsibility of the Lawrence Radiation Laboratory, Livermore, Calif. Mining and excavation were two fields that received early consideration as areas in which nuclear explosives might be used. Knowledge gained from underground weapons testing increased this possibility, and the development of the thermonuclear device which has a small fission-to-fission ratio, reduced the hazard of radiation, and spurred interest. Nuclear explosives appear to have the greatest potential in the following mining operations: 1.— Surface Mining a) Stripping of waste for open-pit excavation b) Breaking of ore in open-pit mining c) Quarrying d) Blasting for production of aggregate, riprap, etc. 2. — Underground Mining a) Block caving application b) Crushing of ore for in-situ leaching, etc. c) Preparation of underground waste disposal areas Of the potential applications, excavation is perhaps the most obvious and the best understood, and probably the most practical for use in the near future. Large quantities of rock and earth can be moved by proper emplacement of nuclear explosives, but economic and practical relationship must be determined between the known capabilities of nuclear explosives and the required excavating to remove overburden. REMOVING OVERBURDEN IN OPEN-PIT MINING Removing the overburden is one of the largest jobs in open-pit mining. In 1960 open-pit mines produced approximately 130 million tons of coal, 108 million tons of copper ore, and 135 million tons of iron ore. To obtain this much production, an estimated 3-billion tons of overburden were removed from the coal, 216 million tons from the copper ore, and 135 million tons from the iron ore. These figures do not include the initial stripping required before ore production. For example, the ASARCO Mission mine started stripping operations in August 1959 and by mid-November 1961 had removed 46.3 million tons of material including 1.2 million tons of ore.* Initial excavation of this type offers the most favorable conditions for utilizing the earth-moving ability of nuclear explosives. EXPLOSIVE CASTING FOR REMOVING OVERBURDEN The use of explosives to remove overburden is not a new idea. Conventional explosives have been used for this purpose for many years with varying degrees of success. Several small coal strip operators have used this idea to increase production. At these mines about one-third or more of the overburden is thrown by explosives across the pit and onto spoil piles. The additional costs of drilling more blast holes and more explosives are more than compensated for by a reduction in the time required to uncover the coal, and by an increase in coal production.

Jan 1, 1964

By Frederick A. Subosits

The Lithium Corporation of America's Hallman-Beam spodumene-pegmatite open pit mine is located in the Kings Mountain area of North Carolina. Figure 1. Presently this area of North Carolina is the lithium center of the U.S., if not of the whole world. The Lithium Corporation mine was started in 1968 and now covers 61,000m2 (15 acres) with projected are reserves in excess of 20 years. Lithium occurs at the Hallman-Beam property in a mineral known as spodumene (LiAlSi2O6), a lithium aluminum silicate. The run-of-mine are averages 1.43 Li2O. Figure 2 of the general Mining Division flow sheet follows the concentration of the Li2O to 5.5% and also lists the various by-products that are sold commercially. The unique properties of lithium have led to many commercial applications, some of these including lubricating greases, ceramics, glasses, glazes, welding fluxes, aluminum reduction cells, dehumidifying and air-conditioning equipment, sanitizers, polymerization catalysts, batteries, and pharmaceuticals. (3) (5)

Jan 1, 1978

By Juan P. Camus

One of the most important decisions in mine development is the selection of the mining method. Open pit or underground methods are selected depending on the shape of the deposit, and its position with respect to the surface. When the decision is not clear or evident, then the common rule is to compare underground and open pit projects to choose the one which yields the maximum return. However, in some circumstances' the best alternative is to start-up the operation with an open pit until a point where mine operating costs make more convenient to employ an underground method. In this case, the final pit limit is not directly related with commodity prices and its position is a funtion of capital and operating costs associated with both methods. The goal of this paper is a mans of establishing the proper ultimate pit considering a potential underground mine. The methodology is quite simple and can be implemented to work with a variety of available routines for pit optimization, such as Lerchs-Grossmann, floating cone, network flow and the Lemieux moving cone optimizing algorithm, which is the tool used by the author.

Jan 1, 1992

By Peter K. Achireko, Samuel Frimpong

Design and optimization of open pit limits are of paramount importance because they provide information for evaluating the economic potential of a mineral deposit and for developing short and long range mine plans. Many algorithms and their modifications have been used to design and optimize open pit limits. These algorithms have provided mine planning engineers with pertinent information in designing, optimizing and extracting ore reserves by open pit technology. However, they do not address the random field properties associated with the ore grades and reserves and commodity prices, and thus, fail to yield the truly optimized pit limits in any time horizon. In this paper, a new algorithm, MCSIMFNN, which overcomes these limitations is proposed and used to optimize open pit limits. The random field properties of the ore grade and reserves have been modelled using the modified conditional simulation based on the best linear unbiased estimation and local average subdivision techniques. Artificial neural networks are used to classify the blocks into classes based on their conditioned values. The error back propagation algorithm, in the neural networks, is used to optimize the pit limits by minimizing the desired and actual outputs error in a multi- layer perceptron under the pit wall slope constraints. The optimized pit value obtained by this algorithm has been compared to that from the Lerchs-Grossman's algorithm in a case study. The results are the same, but in random multivariable states, the MCSI MFNN algorithm is the most suitable for pit optimization. The method is also fast since it mimics the operation of the brain in the solution of the pit optimization problem.

Jan 1, 1996

"Chairman: Professor E. P. PFLEIDER Rapporteur: Mr P. R. JANISCHPapers:Optimum design of an open pit by D. A. PhillipsAn open pit design system for stratiform ore bodies by L. A. J. Pronk van Hoogeveen, J. R. Cutland and M. WeirAn open pit design model by R. H. Robinson and N. B. PrennThe Chairman in opening the session highlighted the current situation in the United States of America where some 85 to 90 per cent of all mining (except for coal) is done by open pit methods, and where some 40 per cent of the coal is mined by open pit. The South African industry is, of course, dominated by the deeper level underground gold mines; however, with the aid of an extensive open-pit technology developed in other countries, South African companies arc continuing to explore possibilities of open-pit exploitation of base mineral, coal and diamond deposits. Several successful ventures are already in operation at Phalabora, Optimum Colliery, Kimberley and elsewhere, and South Africa is undoubtedly benefitting in this regard by drawing on the experience of others.The papers of this session were therefore particularly pertinent, particularly when viewed in conjunction with those presented at an earlier South African conference devoted specifically to open pit mining.Two themes dominated the discussion which followed presentation of the three papers at this session. The first related to the practicability of using the reported techniques as a tool for management, and their acceptability as such to mine management. This was, of course, not peculiar to this particular session, but rather the major point of debate over the entire conference.The second theme concerned the reliability of the initial drill hole data on which any open-pit design must necessarily be based. This gave added emphasis to the problem of practicability, for no management is likely to accept an elaborate pit design unless confidence can be placed in the ore reserve assessment.In noting these two features of the discussion, it should be remembered that all the three papers dealt largely with design and pre-planning; there was an unfortunate lack of papers or discussion on the subject of controlling the day-to-day mining of open pits, and this is an area where the potential impact which can be made by the computer is even greater.In introducing his paper, Mr D. A. Phillips pointed out that it was concerned only with optimization, and that it therefore assumed, firstly, an adequate subdivision of the orebody into ore blocks characterized by grade, rock type, structure, etc., and, secondly, an acceptable forecast of costs and mineral prices in order to generate a suitable profit matrix. However, programs dealing with these problems for both massive, disseminated and stratiform ore bodies are available to Roan Consolidated Mines. The method of optimization which he had described had been used on a region split into 28 000 blocks, for which the program used three hours of C.P.U. time on an IBM 360/40 computer. The computer design had provided a three per cent improve¬ment on a normal design of the same area."

Jan 1, 2014

In this paper, the logic and the capabilities of a long term production planning method for open pit mining are presented. The method is the first attempt in obtaining simultaneous solutions to the four interrelated parameters of open pit mining; 1) the mine life, 2) the specific blocks to be mined each year, 3) the amount of ore and waste to be mined each year, and 4) the ultimate pit limits. An efficient cutoff grade can also be obtained through a sensitivity analysis. None of the existing methods can bring such a comprehensive solution to the problem. A production plan for a real life gold deposit is given to illustrate the logic and the capabilities of the method.

Jan 1, 1993

By Graham A. Mathieson

The precise definition of an ultimate or economic pit has, over the years, received much attention in the literature on the subject of mine planning. Unfortunately, relatively little has been published in the area of pit sequencing and scheduling--an aspect which is typically of much greater economic significance both during the life of a mining operation, as well as in the evaluation of an exploration project. This paper discusses an overall mine planning methodology with emphasis on the design of an optimal sequence of pit expansions or phases. Although the concepts given are not new, it is hoped that some practical suggestions will be made. The paper will also describe graphical techniques which have been found useful in comparing the merits and impacts of alternate planning strategies and production schedules.

Jan 1, 1982