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During the past decade, since the appearance of Popoff's (1966) review of grade tonnage calculations, it has become evident that defining a new method which could be followed step by step by a technician and which would improve reserve estimation was not a simple thing to do. Some concepts have emerged though, and most definitions of ore reserve now require a statement of reliability (USGS, 1975; and Zwarten-dyke, 1976). Exactly how the reliability should be computed is not a straightforward process. It also became apparent that not only was reliability a requirement but that additional questions such as how to predict mining re- serves from geological reserves were to be asked. In fact what became obvious is that specific models have to be designed for each type of mine and for each type of question which is asked. Most methods can be encased within a unique general geostatistical, model, but it takes considerable custom tailoring, and there are still questions that are left unanswered. In this chapter, before giving techniques, we intend to first review what should be required from a grade tonnage calculation done at the exploration stage. If the final objective is still to specify a tonnage and grade, with eventually a reliability, many qualifications have to be made before quoting, and of course, calculating these two numbers. Then the currently avail- able methods will be reviewed and future trends will be shown; finally a few case studies will be given and recommendations about the choice of a model will be made.

Jan 1, 1979

By C. Ottergren

A process does not have higher capacity than what can pass through its bottleneck. Acknowledging this, and with the goal to optimize production at a minimum investment, one can use existing equipment, modify the process flow and make a few strategic capital investments. Automatic setting regulation is a technology that allows balanced crusher performance matching minute changes in feed material characteristics. The system makes it possible to utilize the crushers fully at all times. It also continuously and completely compensates for manganese liner wear.

Jan 1, 1999

By Paul D. Tomlingson

World class performance is the ultimate objective of many maintenance organizations. It marks the organization as a leader in its industry and sets it apart as the ultimate achiever. But what is a “world class” standard and how can it be achieved? Is there a yardstick by which an industrial organization can measure the relative performance of its maintenance activity and compare it with performance levels that universally identify “world class” status? Are there financial formulas, achievements, evaluation techniques or indices that provide this yardstick?

Jan 1, 2006

By Hongjie Yu, Rakshith Shetty, Claudio Cimiotti, Nick Karlin, Mike Mooney, Vitaly Proshchenko, Matt Kendall

This paper documents an effort to explain cutterhead torque behavior observed during slurry pressure balance TBM tunneling through soft ground on the Los Angeles Clearwater project. AI machine learning and mechanics model-based learning was used to characterize cutterhead torque behavior including the TBM operating and ground parameters that influence cutterhead torque. Also, key parameters were from the slurry circuit data, including fines content, in-situ density, pore water fraction and solids content were included. The paper details what was learned using these new data-driven approaches as well as limitations with AI machine learning.

Jun 23, 2024

By Ernest M. Spokes

Starting in 1980, a committee of the National Research Council studied the question of why some underground coal mines are safer than others and what could be done to improve the ones with poorer performance. The results indicated that safety is improved by management commitment to safety, by cooperation between labor and management on safety matters, and by quality training of employees and managers. Younger mines have higher accident frequencies, but are less likely to be killed or permanently disabled by a lost-time accident. Methods for improving safety performance are proposed.

Jan 1, 1983

By Thomas P. Meloy

Floating "fines" differs from floating "sands" because the fines have a much larger surface area compared to their mass. The forces that arise from this large specific surface the key to understanding the behavior and treatment of fine particles. Though the nature of these forces is not thoroughly understood, enough work has been done to give a qualitative picture of what is happening in a flotation cell. It is the purpose of this chapter to re-examine some of the more, recent theoretical work and-to indicate its importance.

Jan 1, 1962

By G. Heinrichs

This paper is intended to provide information for one to be able to determine the slurry system head curve for pump applications. The slurry characteristics are the basis for what the size, material of construction, and critical carrying velocity of the pipe will be. The system head curve is adjusted by use of the pipe friction coefficient factor and slurry derate factors. An example using multi-staging of slurry pump curves is presented to compare the wear life relationship of pump parts for a tailing pipeline system head curve.

Jan 1, 1996

By J. G. Pippenger

The Coteau Properties Company's Freedom Mine is a surface lignite mining operation utilizing large draglines, trucks and shovels, tractor-scrapers, and bulldozers to uncover a single coal seam. In 1989, a work order system was instituted to record data by equipment type, cost, productivity, and distance, and to provide historical information for planning the most efficient and economic use of each equipment type in the mining operation. This report explains how the work order system was initiated, what data is tracked, and how the data is utilized for equipment and project scheduling.

Jan 1, 1994

By F. Cappel

Except in a few special cases, it is necessary for solid fuel direct reduction in rotary kilns that iron-bearing materials be charged with a minimum grainsize of approx. 5 mm. For fines not usable in such form, the combination of sintering - as agglomeration step - and direct reduction were investigated. During reduction of sinter in rotary kilns prevail dependencies on sinter quality and varying reaction parameters, owing to the use of different coals, which led to a definite statement as to what quality sinter must have and which coals can be used.

Jan 1, 1983

By S. Luning

In the nineties the gold sector in Burkina became subject to internationally prescribed liberalization policies. The national state is at present only one of many players. Who are these players, and how are they involved with one another in organizing goldmining activities and prospects in Burkina? One mining site serves as a case to study the scope of players and the types of authorities they build upon in governing gold sites. What conclusions can be drawn in regard to the present position of the Burkinabe state within this field of governing authorities?

Jan 1, 2007

Dunn has written an excellent paper providing a wealth of advice on what is often the most costly consumable in the mineral processing plant. As he pointed out, grinding media selection and quality control can play a major role in successful plant operation. Owing to the economic importance of this topic, there are some important factors related to media sizing that I believe merit further comment. Dunn made reference to a slightly simplified version of the Azzaroni (1981) equation and pointed out its successful use for the Henderson SAG and Climax ball mills.

Jan 1, 1991

By Glenn M. Boyce, Timothy R. Coss

Microtunneling first appeared with some regularity in the United States in 1987. Until then, only Japan and Germany utilized this method of construction. Its high costs initially limited its application to special situations. The last ten years have seen the use of new pipe materials, new machines, new cutterheads, new techniques, and an average growth of30 percent each year. This paper documents the growth and changes that have occurred with microtunneling. Based on current industry practices and advances from abroad, this paper postulates what the next ten years may hold.

Jan 1, 1997

By Greg Barfoot, K. Payne

Condition monitoring of conveyor belting has become an established tool for maintenance programming, replacement strategies and quality assurance for belt conveyor systems. What is less well known is that the condition of the conveyor belting is usually a symptom of problems in other areas rather than the problem source. This paper presents an overview of the state of the art in belt monitoring and the move towards on-line NDT systems. The use of belt monitoring data as an indicator for overall system design, maintenance and operation is also discussed.

Jan 1, 1996

By Richard R. Klimpel

This article introduces the basic definitions and philosophy behind process hazard evaluation procedures and the determination of risk as being a function of accident probabi1ity and accident consequence. The general concepts of good engineering practice and predictive hazard evaluation are discussed. The most commonly employed methods used in the processing industries are reviewed with an eye towards briefly presenting what each method offers as far as information, time and resources required, etc. Some initial references on the actual practical use of each technique in the processing industries are also given.

Jan 1, 1991

By Larry Sevenker

On the basis of favorable salt characteristics, primarily compressive strength and impermeability, solution-mined cavities can provide structurally stable isolation chambers for waste. Solution mining techniques are established for storage of hydrocarbons. The proposition of waste isolation in engineered salt cavities is similar to this practice relative to characterization, certification and safeguards. What materials are isolated and how operations are conducted are principle differences. Compatibility of wastes with other wastes must be considered, but hazards can be precluded by avoiding certain mixtures. Waste material characteristics and cavity considerations are discussed.

Jan 1, 1981

By C. V. Baltzer, E. L. J. Bingham

Compliance with the EPA's emerging Clean Water Act regulations can be challenging. Open pit copper mines in Arizona have found themselves in a tangled web of changing rules, regulations, and guidance documents regarding storm water and process water discharges. Large mining properties must come up to speed on a myriad of issues including the definition of zero discharge, what constitutes a process related spring or seep, and tailings and waste rock Best Management Practices. The example of the Pinto Valley Mine in Arizona is used to illustrate National Pollution Discharge Elimination System regulatory issues.

Jan 1, 2001

By Terry W. Mellors, Robert J. F. Goodfellow

The underground industry has been forced to reconsider risk management sincethe introduction and implementation of the “Joint Code of Practice for Risk Management of Underground Works in the UK” published in 2003 and the subsequent international version published by the ‘International Tunneling Insurance Group’ (ITIG) in January 2006.What does this mean for major tunnel projects in the US and elsewhere? The discussion will highlight the implementation of the Codes to date, risk management principles embodied in the Codes and the use of risk registers as a projectmanagement tool and the management of risk.

Jan 1, 2007

By E. M. Spokes

Starting in 1980, a committee of the National Research Council studied the question of why some underground coal mines are safer than others and what could be done to improve the ones with poorer performance. The results indicated that safety is improved by management commitment to safety, by cooperation between labor and management on safety matters, and by quality training of employees and managers. Younger miners have higher accident frequencies, but are less likely to be killed or permanently disabled by a lost-time accident. Methods for improving safety performance are proposed.

Jan 1, 1987

By Steve Kral

As the current boom in the global mining industry rumbles on, mining companies have had to step up their efforts to replace mined reserves. Many of the majors are replacing and adding to their reserves and resources through acquisitions. This situation has allowed junior mining and exploration companies to do what they do best. They have been re-examining once uneconomic gold, copper and other metals properties with an eye to partnering with a major to develop them. And mines that have been closed for years due to poor economics are being given another look.

Jan 1, 2006

By Steve Kral

The mining industry in northern Ontario is known mostly for its huge nickel deposits. Inco’s and Falconbridge’s nickel mines in the Sudbury Basin are the best known. And with nickel prices being what they are, interest in the region continues. And how. Inco and Falconbridge want to merge. Teck Cominco wants Inco, but without Falconbridge. Xstrata made a hostile bid for Falconbridge, which Falconbridge rejected. And, in June, Phelps Dodge trumped them all when it made an approximately US$40-billion friendly offer for Inco and Falconbridge in a two-part deal.

Jan 1, 2006