Search Documents

By Mark E. Gershon

A mixed-integer formulation of the mine scheduling problem is discussed and applied for the purpose of optimizing both the mine production sequencing and the mill blending and processing problems simultaneously. Previous attempts at solving these problems separately, although successful, fail to take into account the interrelationships between these problems. Project structure serves as the outline of this paper, which is directed towards a mining engineering audience. Generalized in its organization, this concept is useful for long, intermediate and short range scheduling. Actual applications are mentioned which show that the concept is also applicable to mining a variety of ores.

Jan 1, 1982

By M. E. Gershon

A mixed-integer formulation of the mine scheduling problem is discussed and applied for the purpose of optimizing both the mine production sequencing and the mill blending and processing problem simultaneously. Previous attempts at solving these problem separately, although successful, fail to take into account the interrelationships between these problems. Project structure selves as the outline of this paper Generalized in its organization, this concept is useful for long, intermediate, and short range scheduling. Actual applications that show the concept also is applicable to mining a variety of ore are mentioned.

Jan 1, 1984

By M. E. Herrera

The use and effectiveness of sealants in under-ground mines is a recognized and well accepted practice by many people in the mining industry. Their use however in many cases is to correct, or attempt to correct, problems that might have been avoided with sealant use in the early stages of development, and continued thereafter.

Jan 1, 1982

By Kot Unrug

Mine seals are necessary in nearly every mine to isolate mined-out areas from the ventilation network. There is a large number of seals in active mines and that number continually increases as the development spreads across the reserves. The recent accident caused by the failure of seals in the Sago mine resulted in new regulations. These regulations have been set based on a principle of eliminating the risk of failure, rather than the sound engineering and understanding of the conditions that may cause seal failure during an explosion of methane in sealed areas of the mine including the probability of such occurrences. This paper discusses the following subjects related to mine seals: The potential causes of methane explosions and the dynamic effects of pressure wave propagation. Seal materials and methods of construction in view of the interaction of the seal with the host rock environment as well as requirements for gathering geotechnical data. The design of seal dimensions is based on loading conditions, therefore the probable ranges of such loading is reviewed. There is also discussion of possible methods for shielding of seals from pressure pulses following an explosion. Particular seal?s types are examined in reference to the conditions at the seals location. A novel design is presented that will be a low- cost solution for the sealing of mined out areas. Recommendations are given for further research leading to a rational engineering system for design of new seals in coal mines.

Jan 1, 2008

Many mining operations generate seismic signals. They come from blasting and from underground mine failures such as rockbursts, longwall first caves, coal bumps and pillar collapses. Traditionally, seismic motions have been of concern on a local scale because they could create damage to structures at the mine site or at neighboring locations. Recently, there has been much interest in the Comprehensive Nu-clear-Test-Ban Treaty (CTBT). It prohibits any kind of nuclear explosion, anywhere. So distinguishing signals of mining operations from a possible nuclear explosion becomes important. An international monitoring system (IMS) is being implemented to verify the Treaty when it is ratified. It includes a large number of seismic stations capable of recording signals at regional (200 to 2,000 km or 124 to 1,240miles) and teleseismic (more than 2,000 km or 1,240 miles) distances.

Jan 1, 2000

By S. M. Spottiswoode

Much as one hopes to predict whether damaging seismicity might occur somewhere in the next shift, this is not possible at present. Recently, an analysis of seismicity at two mines has shown that a small increase in seismicity occasionally occurs before both large and small events. This analysis is extended here to five mines, with the same results. Earthquake seismologists forecast hazard in terms of the average incidence of earthquakes over the last 50 years, adjusted on an hourly basis according to the possibility of aftershocks of events that have happened. The rate of seismicity in any area remains approximately constant when expressed as seismicity per area mined, or better still, per unit of elastic strain energy released. It is suggested that seismic hazard in mines be estimated using historical seismicity and forward modelling, adjusted according to the possibility of aftershocks. In summary, medium-term forecasting of seismicity is viable; short-term prediction of large events is not.

Jan 1, 2010

By M P. Sandy

Some Western Australian underground mines are challenged by very high stress gradients. This environment frequently results in poor induced ground conditions and damaging seismic activity. In some cases, rockbursting or squeezing ground has been observed as shallow as 250 m below surface. Very few mines operating at depths greater than 500 m experience no stress-related issues. As a general result of this difficult environment, there are a growing number of mines that are now challenged or have been closed by induced geotechnical problems. Often, the up-front savings or perceived advantage of an inappropriate mine plan may be entirely lost to the real cost of managing the hazards, or a write-down of reserves resulting from access difficulties will diminish the economic position of the mine. From an engineering perspective, it is best if stress-related hazards can be proactively minimised, because reactive measures offer less improvement in risk exposure. In this paper, some examples of sequencing techniques for managing difficult environments are contrasted with examples from mines where developing hazards have adversely affected production or the economic viability of the project.

Jan 1, 2003

By T. M. Ruff, W. G. McCoy, M. J. Beus, S. Iverson, W. Hasz

Technology to enhance safety during mine hoisting has been developed by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Assessment of current hoisting technology suggests that monitoring conveyance position and load directly from the skip or cage top offers several significant safety advantages. Wireless data transmission schemes and a package consisting of sensors, batteries, and a charger mounted on the wire rope and skip have been developed. A state-of-the-art automated hoisting test facility was constructed to test the concept in a controlled laboratory setting. Field tests in a fill-size shaft are underway.

By M. J. Beus

Technology to enhance safety during mine hoisting has been developed by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Assessment of current hoisting technology suggests that monitoring conveyance position and load directly from the skip or cage top offers several significant safety advantages. Wireless data transmission schemes and a package consisting of sensors, batteries, and a charger mounted on the wire rope and skip have been developed. A state-of-the-art automated hoisting test facility was constructed to test the concept in a controlled laboratory setting. Field tests in a full-size shaft are underway.

Jan 1, 1999

By T. M. Ruff, W. G. McCoy, M. J. Beus, S. Iverson, W. Hasz

Technology to enhance safety during mine hoisting has been developed by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Assessment of current hoisting technology suggests that monitoring conveyance position and load directly from the skip or cage top offers several significant safety advantages. Wireless data transmission schemes and a package consisting of sensors, batteries, and a charger mounted on the wire rope and skip have been developed. A state-of-the-art automated hoisting test facility was constructed to test the concept in a controlled laboratory setting. Field tests in a full-size shaft are underway.

Jan 1, 1999

By Richard A. McIvor

"All mine shaft conveyances in Canada and most of the United States that are supported by a single hoist rope or attachment point and used for transporting persons are required by regulation to be equipped with safety catches and mechanisms. These safety mechanisms, commonly called safety dogs, are designed to stop and hold a free falling conveyance, with a full personnel load, in the event of a hoist rope or attachment component failure. The conveyance’s safety mechanism must be tested under dynamic conditions before it is used to transport personnel. This paper will discuss free-fall testing and it’s results on conveyance free-fall tests performed in the test tower at INCO Limited, Sudbury, Ontario.Topics covered will be free-fall tests on various wood types such as B.C. fir, Karri wood and Trusjoist MacMillan Limited Parallamwood (PSL), comparison of deceleration rates versus free-fall velocity and the influence of safety dog tooth design on deceleration rates."

Jan 1, 1996

Detect fires in or near mine shafts, isolate smoke filled areas, and remotely extinguish fire. Approach A system (of sensors, automatic alarms, an aboveground control console, remotely operated ventilation doors, and sprinklers) has been built from off the-shelf components, and fire, tested in two mines. How It Works The system uses three different kinds of sensors that can detect the heat or smoke of a fire and automatically actuate alarms. When the alarm sounds in the control center on the surface, water sprays in the mine shaft and shaft station areas can be remotely turned on to deluge both the inside and the outside of the mine shaft's wooden support structure. To protect miners from toxic fumes, smoke control doors can be closed or opened, either remotely from the control center or directly by miners using the manual or electrical actuators at the door locations. Man doors built into each ventilation door allow persons to pass without opening the main door.

Jan 1, 1977

By Guy A. Johnson

In 1976, The Bureau of Mines developed a prototype system to sense and extinguish fires in shafts and shaft stations in underground metal and nonmetal mines. Subsequent work modified this technology to include fueling areas, spontaneous combustion zones and coal mines. This paper updates IC-8783 "In-mine Fire Tests of Mine Shaft Fire and Smoke Protection Systems," which was published in 1978 and summarized the design and in-mine, actual fire testing of the first prototype mine shaft fire and smoke protection system. This paper also updates related work from IC-8775 "Spontaneous Oxidation and Combustion of Sulfide Ores in Underground Mines," (also published in 1978) and IC-8808 "In-mine Evaluation of Under- ground Fire and Smoke Detectors," (published in early 1979).

Jan 1, 1982

By Marcel M. Djivre

The paper will outline the destructive test methods and test procedures including the evaluation criteria currently used at the Materials Testing Laboratory (MTL), Sudbury, Ontario, Canada, a laboratory approved by the Ontario Minister of Labour for the purpose of testing or examining mine shaft ropes or other hoisting appliances. For the evaluation of the mechanical properties of rope samples used in "ultra-deep" single-lift shafts, additional discard criteria used in Ontario, Quebec and South Africa shall be presented. Most of the methods and test procedures currently used at MTL can also be found in the current CSA G4-00 Standard, Steel Wire Rope for General Purpose and for Mine Hoisting and Mine Haulage, published in November 2000. In this latest or sixth edition of CSA Standard G4-00, a new Clause 14 has been added outlining the requirements for in-service destructive testing of steel wire ropes for mine hoisting applications. The CSA G4-00 Standard is also intended for the manufacturing of new ropes, and includes requirements for raw materials and construction features for round strand and flattened strand rope, and locked coil rope in bright and galvanized finish. To-date the Ontario Mining Regulations require only that destructive test of new ropes be performed in accordance with CSA Standard G4-00, but does not require conformity to the Standard, and on the other hand the inservice wire ropes are required to be tested in accordance with CSA G4 and thus require conformity. The author recommends that the Ontario Mining Regulations (and regulations of other mining jurisdictions) be improved in order to ensure quality control in the manufacturing of wire ropes destined for mines in Ontario (and Canada). Also, the author recommends the revision of the CSA G4-00 Standard by the technical committee in order to address manufacturer?s concerns with respect to compliance, and harmonize the Standard with Internationally recognized Standards.

Apr 1, 2005

By Marcel M. Djivre

The paper will outline historically the different materials used for pouring sockets and illustrate the current trend due to inherent advantages. A section will be devoted to engineering stress analysis showing the criteria necessary for the wires not to slip inside the poured socket material. The Ontario Mining Regulations pertaining to poured sockets will be reviewed with emphasis on the acceptable type of sockets depending on usage. In addition the paper will review the proper socket preparation techniques and explain the destructive testing conducted at the Materials Testing Lab essential for the certification requirements. In conclusion the paper will show the importance of the Certification Program for the safety of Miners working in Ontario, Canada and the World. The paper is also intended to inform the Mine Operators and Consultants that to-date the .Wirelock. sockets have been used safely for hoist ropes of locked coil and non-rotating construction and for the termination of balance ropes, and that further research is required on the construction of a socket approved for rotating type mine hoist ropes.

May 1, 2003

By D J. Kilkenny

Work practices involved in shaft construction can be aligned with current industry standard operating practices. However, the working environment during conventional shaft construction introduces unique conditions which can not always be overcome by hard engineering controls. To provide an improved working environment, future shaft diameters will generally be greater than has historically been the case for the Australian hard rock mining industry. This paper aims to explore both what can be constructed from the contractors perspective, and how does an owner extract maximum business efficiency from an asset that in many ways is likely to be larger, more complex and more expensive than initially envisaged.Newcrest Mining Limited, or an associated company, has constructed two major shafts over the last seven years. In both cases, Byrnecut Mining, or an associated company, was the contractor engaged for the shaft sinking activity. The first is the 1127 m deep, 7.0 m diameter production and intake airway at the Telfer Gold Mine, the second is a 295 m deep, 5.5 m diameter split shaft at the Gosowong Gold Project in Indonesia that was primarily designed as both an intake and exhaust airway. Importantly both shafts are designed to provide emergency egress from the respective underground operations.From an Australian shaft sinking perspective, the construction of these two shafts resulted in the following learnings: •constructability is of equal importance to desired functionality;•allow six months of interactive design between the owner/engineer/contractor/regulator to get it right;•shaft sinking and equipping are intimately entwined, therefore engineering of both needs to be complete prior to any activity commencing; and•the mobilisation of both equipment and experienced personnel to a new shaft sink takes up to eight months.Shaft sinking is not extinct in the Australian hard rock mining industry. But, if you are considering constructing a shaft, approach it as a long life asset, front end planning to a high level of detail is required to unlock its full value. Think – plan – think and remember it’s going to take 12 months to get from the whiteboard to firing the first cut.

Mar 21, 2011

The Department of Mineral Resources has a statutory responsibility for mine site environmental management and control in New South Wales. The Department is focusing on an environmental management systems (EMS) approach, as a management tool to achieve æbest practiceÆ outcomes both within our own organisation and on mine sites. One of the DepartmentÆs tools is environmental risk assessment and management which incorporates the Mining, Rehabilitation and Environmental Management Process (MREMP). The MREMP was introduced many years ago in order to integrate the activities of key stakeholders who may have a material interest in the mine. The MREMP provides an ideal mechanism by which ædue diligenceÆ requirements and environmental management programs can be integrated into mining operations and lead to a sustainable post-mining land use.

Jan 1, 2002

By M. C. Bétournay

Mine site infrastructure for storage and delivery of hydrogen must be standardized and acceptable for routine and safe industrial use before fuel cell technology is adopted as a major power source. An initial study reviewed possible options for production, storage and delivery of hydrogen for underground equipment. The high level review included assessment of economic, operational, technical, and health and safety risks. Following this review, a subsequent theoretical study to select typical minesite infrastructure and for construction at an operating research mine is outlined.

May 1, 2007

By S. J. Kohut

Until recently SX-EW technology has only been used to produce conventional cathode for the cyclical commodity marketplace. Unlike electrorefining, SX-EW lends itself to the integration with the downstream manufacturing technologies for direct mine site production of value added products. The integration of SX-EW and downstream manufacturing results in the elimination of redundant process steps, the cost savings, and the access to value added product markets which can buffer the producer from swings in the cathode market. SX-EW production of copper powder and powder-based products has been demonstrated at the pilot plant level. The SX-EW process has been successfully redesigned to meet the more specific demands of engineered products. Challenges include the solution purity, the cell ventilation, the high current density operation and the product handling. Successful demonstration of mine site production of value added SX- EW products opens up new non-commodity marketplaces to the mining industry.

Jan 1, 1999

By A Markham

Stream diversions are a common feature of mine sites worldwide. From an operational perspective, a fundamental requirement of a stream diversion is that it should convey water flows between two points in a safe, controlled and predictable manner. On the other hand, rivers and waterways are naturally dynamic systems, and many of their natural values are achieved through their ability to alter their forms and processes over time in response to flow events - often in a potentially unsafe, uncontrolled and unpredictable manner. In order to ensure that diverted river reaches achieve the dual objectives of short-term operational stability and longer term physical equilibrium with surrounding landscapes, alteration of form and process must somehow be understood and incorporated into the design process. However, performance targets for waterways are not always easy to define and assessing what is good and bad in such variable systems can be difficult. This paper discusses the role of the stream diversion from the operational, environmental and regulatory/relinquishment perspectives, and how stream diversions must achieve physical stability in the short-term, but dynamic equilibrium in the long-term.CITATION:Markham, A, 2012. Mine site stream diversions - A balance of competing objectives, in Proceedings Life-of-Mine 2012 , pp 215-218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012