Search Documents

By A. Mull, J. Weyer, J. Brune

"The “Reiche Zeche” mine in Freiberg, Germany, a 600-year-old lead-zinc-silver mine with extensive open mine workings, experiences severe ventilation losses due to leakage. Much air leaks into abandoned workings, decreasing the airflow available to active working areas. Usually, this leakage occurs in remote areas that lack transportation infrastructure like roadways or rail, making it difficult to haul construction materials to the sites to erect passive ventilation controls such as stoppings, regulators and seals. Transportation distances make it impractical to hand carry traditional construction materials, such as bricks and concrete. Alternative materials, such as brattice, foaming polymers, concrete canvas, and some innovative ventilation control designs have been investigated for this purpose. The suitability of the materials investigated depends on many factors including the pressure it can withstand, the ease of transportation, and workability. Impacts of mine water must be considered, as the Reiche Zeche is below drainage and experiences significant inflow of water. Researchers must consider the effects water inundation as well as how the stopping construction material reacts to being exposed to acidic mine water. INTRODUCTION Problem Statement Mining in the area around Freiberg, Germany began in the 12th century. The mine is used for research, mining engineering education, tourism and air conditioning for a local hospital. The first records of mining in the Reiche Zeche are from around 1384. Due to the strength and competency of the host rock, many of the oldest workings still stand and remain open today, although they may not be accessible. Reiche Zeche also connects to several other, closed mines in the area that are largely unmapped. This allows air to leak into neighboring mines, reducing the air available to ventilate to the working areas of Reiche Zeche. In order to improve ventilation efficiency, it is necessary to control the ventilation and reduce leakage by constructing seals, stoppings and regulators. A challenge with building traditional seals and stoppings in the Reiche Zeche is that the old workings lack transportation pathways or rails. Also, the lack of compressed air, water or electricity makes it difficult to operate power tools and drills. This means that construction materials must be hand carried – some over distances of several kilometers. Figure 1 shows a typical drift in the Reiche Zeche. Researchers investigated using lighter, more easily transportable materials including concrete canvas, expanding polyurethane and polyurea foams, and brattice. The applicability and utility of these materials depends on a variety of factors including the ventilation air pressure, chemical resistance to acidic and mineral-laden mine waters, ease of transport, and ease of construction. Stoppings and seals must be substantially constructed so that they remain tight and do not require maintenance. It is also important to consider the toxicity of the construction materials in case of a mine fire."

Jan 1, 2016

By B. Schimm

Mining of material without blasting and / or selectively becomes more and more important for high quality ROM-products. Surface Miners have been developed especially for this purpose. The cutting technology of these machines has been improved, so that harder material as well as wet and sticky materials can be cut with better results now. Especially the cutting drum design and more precise drum manufacturing process now allow production and equal tool wear over a long period. The better knowledge of rock parameters influencing the cuttability and cutting results allow higher production, less cutting tool wear and therefore reduced production costs.

Jan 1, 1999

By E. Topuz

The objective of mine ventilation is to provide suitable environmental conditions in working places at an economical cost. Maintaining a stable air flow, i.e., a flow quantity and the direction, is of vital importance. In practice, however, air flow quantity in underground openings varies continuously. Therefore, the stability of air flow means relative stability that is the flow in a branch moves along a certain direction while the variation in air quantity stays within acceptable limits. Many underground mines have low stability of mine air flow because almost all types of ventilation systems involve complex diagonal branches through which air flow quantity and, more importantly, the air flow direction may change easily. This creates extremely hazardous, unstable conditions, especially during emergencies. This paper deals with the directional stability of air flows in underground mines in single or multiple fan systems. It examines the rules of directional changes of air flows in diagonal branches, and proposes a method of calculating the stability conditions. It provides a criterion that may be used in designing new mine ventilation systems to ensure a desired degree of stability or in improving the existing systems.

Jan 1, 1986

By C. C. Nolan

As the size of the mills get larger and the liners get heavier, a better means had to be found to handle liner replacement. McLellan Industries is famous for their innovative ideas and was called upon by an engineering company to develop a mill liner crane. The first crane was developed for Similkameen about 1969 to serve a 32' 0 x 14' Long SAG Mill. The next was Island Copper in Port Hardy, B.c., the same size as Similkameen in 1970. At that time, we took existing hydraulic cranes and modified them to meet the mill configuration. In 1973, we developed a completely new approach for the Southern Peru copper mine at Tacna, Peru for a Ball Mill, size 16'-6" 0 X 19' Long. Each installation required a design study to meet the change in mill size, trunnion size, elevation of floor to feed trunnion, area at the feed or discharge end of the mill. We have supplied self-propelled units as well as lift in. When there is no room at the feed end and if the mill has a trunnion overflow discharge, we have the mill supplier provide a structural frame to span the sump and move the mill liner handier into position with the use of the overhead crane or a mobile crane.

Jan 1, 1999

By William Ives

My presentation is from the viewpoint of the industrial mineral geologist, which is a relatively rare breed. Very few geologists become involved with industrial minerals for two reasons, I think: (1) Much of the industry utilizing non-metallic minerals has developed without the use of geologists in the begin¬ning and many of the management people, who generally derive from the processing plant supervision, tend to take raw materials for granted; and (2) non-metallic minerals are a very insignificant part of the curriculum of virtually all colleges granting a geology degree. One learns about the geology of industrial minerals by working with it. This "on-the-job-training" is probably best because it brings the geologist into close quarters with the production people and the production process. And the industrial minerals field has a distinctiveness when compared with the petroleum or metal mining field in that each deposit can yield a material differing in some aspect from that in any other or within the same deposit. The petroleum from a well in a given field will be similar to that from any other well, but a limestone on one side of a hill can differ signifi¬cantly in elemental composition, calcinability, soundness, specific gravity, or some other factor from the same ledge on the other side of the hill. This characteristic of almost certain variability creates problems sooner or later and provides for much of the employment of industrial mineral geologists. My job seen from the viewpoint of management is "Find us some rock we can extract and process at a profit." The industrial non-metallic geologist has much the same problems and approach as a detective. I do not mean the TV variety with the big mouths and the unfailing knack of spotting the wanted criminal immediately in a city of ten million people. Any real detective will tell you it takes leg-work, knowhow, and persistence to make a case. The same is true for the geologist who finds rock which can be quarried at a profit. I am responsible for finding raw materials for a company which manufactures portland cement and

Jan 1, 1977

By J. S. Roti

Calcium-based scale precipitation is a common problem in mill reclaim waters. An accumulation of these adherent deposits can result in a rapid reduction in water flow, loss of pump efficiency and eventual interruption in ore production. Heap leach applications can also experience the added problems of plugged sprinkler heads, blinded leach pads and fouled carbon columns when scale control is not maintained. The primary cause of scaling in precious metal recovery is the relative insolubility of calcium carbonate. The presence of the calcium ion and bicarbonate alkalinity is common in almost every water source. If the temperature or pH of the water is allowed to increase, the bicarbonate breaks down to carbonate and combines with calcium by the following reaction: Ca +2 +2HCO3 ? CaCO3 + H2 + CO2

Jan 1, 1986

By R. Adsero

"In view of the decade long decline in worldwide mine equipment productivity and with heavy economic pressures and survival at risk, improvements for those remaining in the game are essential. The latest Multifactor Productivity data for the US mining industry indicates a continuing descent with Australia on a similar course. The world’s mining industry has a fleet of over 400 large draglines moving billions of tons of material annually. The most efficient use of this equipment resource will provide a competitive advantage to those companies who are committed to improving performance. A dragline monitoring system is a requirement for optimum operations. The monitor reports the facts. Focused actions can change the facts and create improved performance. Analyzing monitor data to build knowledge and create understanding is a beginning. Understanding the key productivity indicators for dragline operations and an effective benchmarking process are the basis for improvement. There is overwhelming evidence that adopting new technologies and concepts including AC drive technology can and will bring about a step change in dragline operating cost with improved production performance.STATE OF THE MINING INDUSTRY A high altitude review of the state of the mining industry provided by a study of multifactor productivity shows a continuation of lower and lower output year on year for the capital and labor inputs applied. The story is sadly similar for both U.S. mining and the Australian mining sector. In fact, according to PwC analysts the worlds mining equipment productivity has declined 20% over the past seven years. (Lumley, 2014) Although the reasons for the continuing decline in mining productivity are varied, the need for improvement is clear. The world’s mining industry fleet of well over 400 large draglines moves billions of tons of overburden and ore (phosphate, limestone, etc.) annually.This discussion will review a few of the tools available for improved productivity in dragline operations."

Jan 1, 2016

By G. A. Christie

This paper presents a vision system capable of providing an accurate estimate for the volume of stockpiles using 2D images. By imaging a stockpile from multiple viewpoints with a two-camera system, a 3D point cloud of known scale is generated using image-based 3D reconstructions. With a small amount of user interaction, the points that correspond to the surface of the stockpile are extracted and used to measure the volume. The hardware required for the two-camera system is light enough to be carried by a small unmanned aircraft and is a cheaper alternative to LiDAR while still being competitive in terms of accuracy. When testing the volume measurement algorithm on a stockpile of known volume, the measured output was found to have less than a 3% error from the ground truth.

By Danny Chan, Shahram Tafazoli, Nicholas Himmelman, Edmond Chow

"While wearable technology has been garnering attention in the consumer market, enterprise and industry have just begun exploring its potential applications. Since February 2014, Motion Metrics International has been working in collaboration with Vandrico Solutions Inc. to apply wearable technology to improve productivity and safety in the mining industry.This article discusses the value proposition of using wearable technology to deliver critical notifications in mining. The advantages and disadvantages of various form factors are explored. The challenges, both specific to mining and in general to wearable technology, are defined. Finally, the concept of MetricsGear, the first wearable technology platform developed for mining by Motion Metrics International in collaboration with Vandrico Solutions Inc., is described. MetricsGear is designed to notify the user with minimal distraction to keep the user focused on his or her primary task and aware of mission-critical events. This focus and awareness allows the user to work more efficiently and safely. The mining process consists of a series of intricate stages, where certain events or conditions in one stage can have a huge impact on other stages. The notification of these critical events or conditions is vital for ensuring the overall efficiency of the mining process. Critical notifications can be classified as two types: timecritical events and contextual information. Time-critical events are situations where a timely response from a responder can have a significant impact on seizing an opportunity or mitigating cost. Some human-computer interaction (HCI) experts classify notification types based on the interruption, reaction and comprehension (IRC) framework. Time-critical events are classified to have high interruption, high reaction and low comprehension due to their urgency. The responder should have just enough information to identify the crisis and react as soon as possible (Chow, 2014). For example, when a tooth is lost during shovel operation, it is necessary to recover the missing tooth before it jams the primary crusher. The consequence of missing this critical time period is a jammed crusher that can cause the mine to be out of production until the jammed tooth is extracted (Baumann, 2013). In this case, the responder only needs to see an image to confirm if the tooth is missing and information to identify which equipment and when the tooth went missing (Fig. 1)."

Jan 1, 2014

By J. O. Costello

Marble is a preferred surfacing material in up-scale buildings. Its use increased in the 1870's with rising national wealth and declined in the 1950's when synthetic materials for these applications were developed. Natural marble is now limited to high-end domestic and commercial structures. Cultured marble is a paste of white marble dust and polyester resin cured in molds yielding fixtures of specific finished dimensions. Dyes incorporated at different stages in the mixing cycle mimic shades and veining of natural marble. This paper discusses the filler requirements for cultured marble production and reviews new techniques to cut and finish natural marble.

Jan 1, 1999

By S. Tafazoli, N. Himmelman, D. Chan, E. Chow

"While Wearable Technology has been garnering attention in the consumer market, enterprise and industry have just begun exploring its potential applications. Since February 2014, Motion Metrics International has been working in collaboration with Vandrico Solutions Inc. to apply Wearable Technology to improve productivity and safety in the mining industry. This paper discusses the value proposition of using Wearable Technology to deliver critical notifications in mining. The advantages and disadvantages of various form factors are explored. The challenges, both specific to mining and in general to Wearable Technology, are defined. Finally, the concept of MetricsGear™, the first Wearable Technology platform developed for mining by Motion Metrics International in collaboration with Vandrico Solutions Inc., is described. MetricsGear™ is designed to notify the user with minimal distraction to keep the user focused on their primary task, and aware of mission-critical events. This focus and awareness allows the user to work more efficiently and safely. INTRODUCTION The mining process consists of a series of intricate stages, where certain events or conditions in one stage can have a huge impact on other stages. The notification of these critical events or conditions is vital for ensuring the overall efficiency of the mining process. Critical notifications can be classified as two types: time-critical events and contextual information. Time-critical events are situations where a timely response from a responder can have a significant impact on seizing an opportunity or mitigating cost. Some Human-Computer Interaction (HCI) experts classify notification types based on the Interruption, Reaction, and Comprehension (IRC) framework. Time-critical events are classified to have high interruption, high reaction, and low comprehension due to their urgency. The responder should have just enough information to identify the crisis and react as soon as possible (Chow, E. 2014). For example, when a tooth is lost during shovel operation, it is necessary to recover the missing tooth before it jams the primary crusher. The consequence of missing this critical time period is a jammed crusher that can cause the mine to be out of production until the jammed tooth is extracted (Baumann, M. 2013). In this case, the responder only needs to see an image to confirm if the tooth is missing, and information to identify which equipment and when the tooth went missing (see Figure 1). Contextual information is relevant information that is valuable for the receiver to be aware of as it can present an opportunity to improve efficiency or save cost. According to the IRC framework, contextual information is classified as low interruption, low reaction, and high comprehension. They are not as urgent as time-critical events, but provides more detailed and informative information to assist the receiver. For example, when a shovel’s worn tooth is predicted to require replacement soon, a notification to a GET technician can help him or her schedule a pre-emptive replacement of the tooth in an already planned maintenance to prevent having to reactively schedule another one when the tooth is critically worn. This helps reduce the amount of equipment downtime to maximize production (Baumann, M. 2013). In this case, the receiver will look at the information when he has a moment to spare to get a quick forecast, and make use of this information as needed (see Figure 2)."

Jan 1, 2015

By S. Rupprecht

"INTRODUCTION This paper addresses the prevalence of poor public reporting practices of Coal Exploration Results, Coal Resources and Coal Reserves in southern Africa. Currently, the reporting of coal tonnage without supporting coal qualities or “saleable” tonnes and quality is a poor reporting practice that occurs far too often. Not all coal is equal – therefore it is extremely important that investors or potential investors are provided with the full details of both run-of-mine (“ROM”) and Saleable coal tonnage, their associated qualities and other material and relevant information. Competent or Qualified Persons should note that publicly reported information should be sufficient to enable an informed reader to make a reasonable and balanced assessment of the significance of the information provide. “Companies are encouraged to provide information in their Public Reports, which is as comprehensive as possible” (CRIRSCO, 2013): too often this isn’t the case and material matters are either not reported or inadequately disclosed. According to the South African National Standard (SANS) 10320:2014 draft document - “tonnage and coal quality that will be available for sale, either in the raw ROM state (raw Saleable) at a specified moisture content, or after beneficiation of the ROM coal by processing operations to produce materials at specified qualities, size ranges and moisture contents. The assessments must demonstrate that at the time of reporting, the marketing of the products is reasonably justified. The basis of the predicted practical product yield to achieve the Saleable Coal Reserve must be stated. The moisture basis of reporting shall be stated.” As an example to why coal qualities are so important to the public, the requirements of South Africa’s electric public utility (Eskom) power stations are highlighted. The Kendal power station, commissioned in 1988, operates at a Calorific Value (“CV”) range of 19 to 20MJ/kg, an Ash content between 29 and 34% and Volatiles between 20 to 21%. Other power stations, such as Kriel or Hendrina, may require different qualities such as a CV range of 22 to 23MJ/kg, an Ash content between 20 and 28% and Volatiles between 22 to 23%. Thus, in terms of domestic saleable coal, it isn’t just about reporting the coal qualities but also informing the investor as to which power station the coal is intended to be sold as “boilers are designed to burn particular qualities of coal” and “it is not always possible to transfer coal between stations because of different quality requirements at each station” (Chetty, 2010). Sulphur content is also another important quality with the ideal coal content having a quality of less than 1% Sulphur."

Jan 1, 2018

By C. L. Schaidle

Computers and communications technology have revolutionized many industries. In earthmoving, this revolution has just begun. The major changes are still to come, but they are just around the corner. This paper presents a vision of this up-coming revolution in our industry. This vision is comprehensive. It includes basic communication, machine monitoring and diagnostics, job and business management, planning and operations, and machine control. For our industry to realize maximum benefits from the information age, we must have a vision of the future that is shared by technologists, machinery producers, and miners.

Jan 1, 1994

By D. Shink

A small scale continuous flotation cell was designed and constructed at Noranda Technology Centre to develop a mobile testing flotation circuit located next to the production circuit. This mobile small scale flotation pilot plant can easily and economically be set up at any circuit in a mill and used to evaluate and predict plant performance against a given flotation condition. The main feature of the cell, beside the provisions of automatic pulp level and feed rate control, is to provide a reduced surface to volume ratio approaching to that of an industrial machine. This paper describes the basic design and the results of various testwork carried out to date including aeration, conditioning, reagents, recirculation, flotation gas, etc. are presented in comparison with the plant production results.

Jan 1, 1992

By George R. Mitchell

It is a common observation that objects having, different; temperatures exchange energy by radiative transfer. The quantity of radiant energy emitted by an object is a definite function of its temperature. Therefore, a measurement of emitted radiation, by means of a calibrated radiometric instrument, provides a temperature measurement without contacting the emitting object. The physical laws describing radiant energy transfer and their application to remote temperature measurement form the substance of this paper. The energy radiated by bodies having temperatures up to 4000°C is largely in the infrared spectral region. The infrared spectral region is that part of the electro-magnetic spectrum having wavelengths longer than visible light and extending to the microwave region. The wave-lengths range from 0.7 micron (1 micron = 10-4 cm) to 1000 microns. In general, infrared radiometry deals, with the methods of measuring energy flux in the 1 to 15 micron region of the infrared spectrum.

Jan 1, 1960

By D. Spitty

Mining companies often have many disparate systems and repositories of data in their organization for planning and scheduling outbound mining supply chains. To optimize ore quality, throughput, transport logistics scheduling and delivery to contract, planning teams need to model and manage the value chain accurately and achieve a consolidated, enterprise view of operational performance. Planning teams coordinate a complex series of activities to ensure production forecast accuracy. They also negotiate and execute complex contracts often with disconnected and limited visibility of production forecasts, quality, and variability with little ability to accurately market potential product specifications over longer time horizons. This market is becoming increasingly dynamic, with increasing variability and the time for planning teams to react is decreasing. This is driving the need towards using science to generate the necessary scenarios required to support the decisions made by planners on a frequent basis. Resource-to-Market is a highly flexible, user-configurable supply chain management system for the mining and metal processing industries. This provides an integrated view of the supply chain that supports the dynamic nature of planning in a mining company, embraces variability of elements across the supply chain with the ability to optimize across all the functional areas of the operation to enable optimal decision making for often competing objectives such as throughput, quality, cost, revenue and profit.

Feb 23, 2014

By Don Cchultz

The United States Forest Service, as a land managing agency, is responsible for the surface administration of National Forest lands. The basic objectives of management are protection and utilization of renewable resources such as water, forage, timber, wildlife, recreation, and clean air. Much of the National Forest land in this country is open to mineral prospecting and development. When large de-posits of minerals are extracted from the forest environment, especially by surface methods, there are oftentimes conflicts between accepted mining methods and the objectives of other resource management goals. Such is the situation in Southeast Idaho where several members of the phosphate industry are operating on and adjacent to the Caribou National Forest. In 1966, the phosphate industry and the Caribou National Forest became mutually concerned with the problems of rehabilitating mined areas and minimizing potential damage to adjacent forest areas. A Cooperative Administrative Study was initiated with industry supporting the Forest Service financially and with equipment, material, and manpower, as well as interest and enthusiasm. The objectives of the study are to provide basic, applicable information pertinent to: 1. Protecting the quality of water emanating from mined water-sheds. 2. Providing for soil stabilization on mined areas. 3. Returning mined areas to surface resource production. 4. The feasibility of making mined areas esthetically acceptable. It was concluded that the following separate--yet intergrated--fields should be studied in order to obtain the desired information:

Jan 1, 1971

By Abb Raymond

Finely processed industrial minerals in "powdered" form have long been utilized by the plastics, paint, rubber, paper, ceramics, and adhesives industries as fillers, extenders, coatings and special additives. These minerals, primarily calcium carbonate, talc, kaolin, titanium dioxide, and the like, have provided economic, uniform and consistent base materials which have, in turn, been used by the referenced industries to manufacture quality products. The focus of this paper will be the development of equipment and systems at ABB Raymond for the dry processing of such non-metallic minerals in order to meet what have become increasingly stringent requirements of the producers of these minerals. Changes in these requirements seem to have been accelerating rapidly during the last ten years, and it is expected this process will continue into the 1990's.

Jan 1, 1990

By Andrew T. Zador

The growing demand for energy combined with the need to protect and preserve the environment have become prime considerations in the design of efficient coal handling ports and their associated stockpiles. The transportation system is analogous to a connected chain which originates at the mines and terminates at steel mills or power plants, in which the port and the stockpile reserves are a vital link. Railroad transportation costs can be minimized by rapid discharge of the cars which, in turn, requires that an adequate stockpile system be available. Ocean transport costs can be minimized by having an efficient high capacity ship loading system and sufficient quantities of coal on hand -all of which also requires an efficient stockpile system to meet shipping demands. The connector between the two modes of transportation, therefore, is the port stockyard. It is here at the interface that optimization of land utilization and materials handling equipment results in a total transportation chain that can operate as a smooth efficient system. Multiple origins of coal require the simultaneous handling of large quantities of coal of many grades. Railroad transportation logistics often limit and define the incoming arrival patterns and limited rolling stock often require priority treatment for railroad operations. The physical limitations of prime ocean frontage require that coal stockpiles be built close to residential or industrial areas which entail strict environmental controls. Large capacity, enclosed coal stockpiles for ocean shipping have not yet been considered feasible but may be forthcoming in the near future. Several have been analyzed.

Jan 1, 1978

By H. Salamanca

The electric operation and design features of the 11.000 H.P. variable speed SAG mill gearless drive is presented. The function of the frequency converter, control system drive and lubrication systems are described. An analysis of the harmonic characteristic in the Supply System and Motor is presented, and the dynamic development of the stator current, speed and the magnetic flux in the start-up process of the drive is evaluated. Besides, the most important aspects in the commissioning and maintenance of the drive are analyzed.

Jan 1, 1991