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By William Gleason

With its 2011 acquisition of rival equipment company Bucyrus International, Caterpillar added underground mining and large shovels to its line of products and further solidified its standing as the leading mining equipment manufacturer in the world with solutions for every aspect of mining. When Caterpillar spent $8.8 billion to acquire Bucyrus, the global mining business was flourishing, as mining companies around the world worked to keep up with demands for nearly every commodity. Flash forward to 2013, and the global mining landscape looks very different. Lower demand for raw material from China and India and falling commodity prices have forced most mining companies to pull back on their production. The reductions from the mining industry have hit equipment makers like Caterpillar and Komatsu hard. In October, Caterpillar reported that its quarterly earnings had fallen 44 percent. The changing conditions have also changed the narrative from Caterpillar and other equipment makers to customers from offering solutions to move the most tons per hour, to now offering solutions for the lowest cost per ton. In September, Caterpillar hosted some of its mining customers and the trade press at its Tinaja Hills Demonstration and Learning Center near Tucson, AZ to talk about its range of products, from its MineStar System designed to help increase efficiency through better equipment management and planning, all the way up to the massive Cat 7495 and 7495HF electric rope shovel lines acquired through the Bucyrus takeover

Dec 1, 2013

By Goran Mathisson

PLASMARED is a process in which one well established and one new advanced technology have been merged into a practical tool for production of high quality direct reduced iron at lowest energy consumption and costs. Before describing the process, we have to reiterate the simple fundamentals of making metallized iron from iron ores: The main components necessary are: - Iron oxide - Carbon and/or hydrogen - Heat

Jan 1, 1982

By Daniel Hodouin, Claude Bazin, Sami Makni

SCOTT COULTER: Thanks, Eric. Thank you all for coming. Our first speaker today is Claude Bazin. Claude received a degree in metallurgical engineering in 1980 from Laval University in Quebec. He worked for a short time in a mineral processing plant and then returned to Laval to complete graduate studies in the field of process modeling and control. He obtained his master's degree in 1983 and his Ph.D. in 1990. In 1987 he joined Brunswick Mining, New Brunswick, as research metallurgist and subsequently process control engineer. In 1990 he joined Helzfield Mines, New Brunswick, as senior metallurgist. In 1991 he accepted a position of professor at the department of mining and metallurgy at Laval University, a position he is still holding. He's a member of the CIM, TMS, and the Society for Mining, Metallurgy, and Exploration. Claude's topic today is "On-Line Material Balance for Flotation Plants." INTRODUCTION CLAUDE BAZIN: During the last two decades, the on-stream analyzer (OSA) has gained the stat& of key instrument for the control of flotation plants. The OSA is currently used in almost every sulphide flotation plant (Leroux and Franklin 1994), and its application to oxide mineral flotation plants is increasing. The OSA assays are sent to the flotation operators via an operator console or to control loops of various degrees of complexity (McKee 1991) implemented in a distributed control system (DCS). Operators and/or controllers take control actions based on these assays to ensure an adequate operation of the plant. Although this application pays off very rapidly for the purchase of the OSA, one could ask, "Could we get more from the OSA?" Some plants reported the use of OSA measurements for process optimization (McKee 1991). The optimization strategy is based upon economic indices calculated from metal recovery using the 2-product formula (Wills 1992, p. 124). The 2-product formula is sensitive to measurement errors in the assays and can lead to considerable scatter in the calculated indices (Hodouin et al. 1993). Least squares algorithms provide a robust alternative to filter out measurement errors (Spring 1992). This paper presents some applications of a recursive least squares algorithm that provides real-time estimates of the mass flow rates within a flotation plant using OSA and mass flow rate measurements.

Jan 1, 1998

By E. Ilgar

Biodegradation of spodumene by Asnergillus niger has been investigated. This organism oxidizes sucrose to citric and oxalic acids (in approximately 50-sot proportions) which degrade the spodumene mineral. The kinetic effects of leach variables on the dissolution of lithium were determined. The maximum theoretically attainable rate of lithium extraction was calculated for the effect of pulp density, to be V : 3.01 x 10 kg m sand the corresponding constant value, K = 12.47% pulp density. The apparent activation energy of lithium extraction vas found to be ^E = 20.3 kJ and frequency factor A = 5.66 x 10 s for S-spodumene leaching by synthetic -3 citric and oxalic acids (each in 0.05 kmol m-3 concentrations).

Jan 1, 1989

By Fred A. Glover

It's a pleasure to be included with this group. I am not here to sell my services, but rather to share with you some ideas and considerations on using environmental consultants. Environmental consultants have developed some problems as well as created new costs for companies that are as legitimate as engineering costs. Each day the mining industry is becoming more affected by the proliferation of environmental regulations and their interpretations by federal and state agencies. How does a modern mining company cope with all the demands for environmental consideration by regulatory agencies and special interest environmental groups-- yet produce a product and make a profit? One way is to make efficient use of environmental consultants. But, as everyone here knows, this approach has been fraught with seemingly inherent frustrations, difficulties, and much justified criticism.

Jan 1, 1979

By Mark P. Walsh

In recent years in situ leach mining has emerged as a viable technology for the recovery of uranium from strata in South Texas which contain relatively low concentrations of uranium ore. Because the ore bodies lie within groundwater aquifers, a significant determinant in the economics is the requirement that such aquifers be protected from contaminantion. Since ammonia is one of the constituents of the leach solutions now being field tested, one environ- mental problem to be resolved is the removal of ammonia at the end of mining. A second related question is the fate of the ammonia which is not removed by the restoration procedure. This paper considers the displacement and migration of ammonium in a flowing electrolyte with concomitant ion exchange. The ion exchange is an important feature since, during the solution mining phase, ammonium saturates the mineral exchange sites and must be removed from these sites. A mathematical model is used to simulate this process and the model is tested against the results of laboratory experiments. It is found that the simulations are adequate if an appropriate selection of parameters is made. The model is then used to investigate the effect of cation composition and concentration of the restoration medium as well as dispersion on the overall effectiveness of the process. It is concluded that increasing the concentration of monovalent ions in a solution containing a mixture of both monovalent and divalent ions decreases the adsorption selectivity of the divalent ions with respect to all monovalent ions including ammonium. Thus increasing the ionic concentration of a restoration fluid by increasing the concentration of a nonselectively adsorbed (with respect to ammonium) ion may have a very limited benefit. Dispersion attending the flow of fluids in a porous medium is also shown to be an important factor. The effect of dispersion can greatly reduce the benefits of having a displacing cation which is adsorbed selectively with respect to ammonium. Since dispersion increases almost linearly with fluid velocity, an optimum displacement rate may exist.

Jan 1, 1979

By Lok W. Home

INTRODUCTION Today, raise drilling (boring) has become the stan¬dard method of raising throughout the Western world. It is estimated that the majority of raise footage com¬pleted in 1977 was accomplished by the raise drilling method. Extensive replacement of the drill and shoot system by mechanized raise drilling has occurred be¬cause users have recognized one or more of the follow¬ing advantages. In a direct cost per meter comparison, mechanized raise drilling is economically more attractive than drilling and shooting. Mechanized raise drilling offers improved personnel safety over the drilling and shooting method. Mechanized raise drilling is a faster and more predictable method for excavation than is drilling and shooting. The raise cost per unit of length becomes less as the raise length increases, offering greater flexibility in the overall design of mines. Mechanized raise drilling provides a substantial reduction in labor requirements. 6) Mechanized raise drilling improves the working environment. 7) Mechanized raise drilling improves the rock in¬tegrity of round, unblasted raises. Increasing acceptance of the raise drilling technique is enhanced by continuing equipment development. Today, a wide range of machines and capabilities is available, machine drive systems have been improved, reliability has been increased, and cutter technology is being improved quite rapidly. Table 1 lists the four major manufacturers of raise drilling machines, cutters, and reamers, together with the approximate number of machines that each company had in operation at the end of 1977. Although Reed and Smith are major suppliers of reamers and cutters, they do not manufacture the drilling machines. Four or five other relatively minor suppliers have built machines, reamers, and cutters for raise drilling, but they did not have a substantial num¬ber of machines in the field at the end of 1977. MACHINES FOR MECHANIZED RAISE DRILLING There are three principal arrangements for making machine-bored raises. They include the use of standard raise drills, reversible raise drills, and blind-hole or box¬hole raise drills. Standard Raise Drills The standard raise drilling machine is set up on one mine level or on the surface, and a pilot hole is drilled from that level or surface to a level below. When the pilot hole has been drilled, the raise then is reamed back from the lower level to the upper level or the surface. This arrangement is illustrated in Fig. 1. Reversible Raise Drills The reversible raise drilling machine is set up on a lower level of the mine, and a pilot hole is drilled up¬ward to a higher level. The raise then is reamed back from the upper level to the lower level. This arrange¬ment is illustrated in Fig. 2. The machines used for this type of raise drilling normally are capable of being used as standard raise drills. Blind-Hole or Boxhole Raise Drills The blind-hole or boxhole raise drilling machine is set up on a lower level of the mine, and a full diameter raise is bored to a higher level without the use of a pilot hole. This type of machine is illustrated in Fig. 3. Drill Recommendations If access to upper and lower mine levels is equal, the standard raise drill should be used. The complexity of the equipment and associated handling procedures for boxhole drilling far outweigh any mechanical advantage or reduction in the number of operations, provided that access to an upper level is available. If there is good access to a lower level but only limited access to an upper level, the use of a reversible raise drill should be considered. If there is no access to an upper level, a blind-hole or boxhole raise drill is the only practical mechanized system. MACHINE SELECTION There are six major considerations in selecting a machine for raise drilling. These include operating range, cutter loading, machine structure and main¬tenance, drill string configuration, drive system, and automated controls. Operating Range As shown in Table 2 and Figs. 4 through 6, raise drilling machines are available for a wide range of hole sizes. Standard raise drill ratings range from raises of 0.9 m (3 ft) diam and 120 m (400 ft) length up to raises of 3.5 m (12 ft) diam and 900 m (3000 ft) length. Boxhole raise drilling machines are available for raises ranging from 0.9 m (3 ft) to 2 m (6 ft) diam with lengths up to 90 m (300 ft). Table 2 lists, among other criteria, the torque and thrust of typical machines; torque and thrust are the main criteria for analyzing the capacity of a machine. The raise sizes shown in Table 2 assume a condition of medium hard to hard rock formations and optimum cutter loading. The recommended raise size for a given machine can be exceeded when raising softer rock formations or when the operator is willing to accept a lower level of performance; the performance is related directly to the 1093

Jan 1, 1982

By Michael von Seebach

High-pressure grinding rolls subject the feed material to pressures of 200 N/mm? During this process considerable size reduction and the Formation of flakes occur. This paper describes the basic consideration For design and operating of this type of mill. It is also shown that the particle size distribution resulting from this process is typical for grinding processes but untypical for crushing processes. High pressure grinding rolls are designed in size of up to 2.8 m roll diameter allowing feed material top sizes of 250 mm. The rigid frame, bearing and drive - train design allows a broad application of the high-pressure grinding rolls operating the machine in open or semi-closed and closed circuit for dry and moist feed materials. Operating results show that capacity increases of up to 100 % can be accomplished with this technology. The high-pressure grinding roll also, allows for lower operating and maintenance costs due to energy savings of up to 20 L and reduction of wear to less than 1 76 for dry and less than 0.1 5 for wet grinding. Other advantages of the high-pressure grinding rolls are smaller equipment sizes than a ball or SAG-mill for a given capacity resulting in lower building sizes with reduced capital in- vestment costs.

Jan 1, 1987

By Edwin G. Johnsen

Underground mining is relatively safe today, but no technique or equipment is completely fool proof and 100% reliable. The only sure way to prevent accidental death or injury to underground workers is to remove them completely from the hazardous environment. This alternate approach to underground work is now feasible. Tunnelling and mining systems can be built that could be remotely controlled by men operating consoles in a surface control room. This concept, called a teleminer, would use recently developed remote control technology to remove man from underground work but still give him the capability to remotely operate mining and excavating equipment as if he were actually in the working area. It is appropriate to present this concept in the session "Environmental Controls" because the rationale for environmental control in underground areas can be significantly modified if man is excluded from the underground operation. The development of teleminers cannot only reduce or eliminate most of the requirements for conventional environmental control, but it can also create new and powerful techniques for rapid tunnelling and excavation. TELEMINER CONCEPT The concept of remotely controlled mining machines is neither new nor untried.(1)(2) Conventional remotely controlled mining equipment employs the standard techniques of extending the controls of the equipment to a remote console. For example, the rotary cutters on a remotely controlled tunnelling machine are started or stopped by a human operator turning a switch on the remote control console.

Jan 1, 1997

By ETHAN FUSTER, STEPHEN LEE, Richard Ray

By offering savings in space and capital cost compared to ducted axial and centrifugal fan systems, horizontally mounted jet fans are commonly used worldwide to ventilate vehicular tunnels. They discharge high-velocity jets to transfer momentum to the surrounding airstream to induce longitudinal flow in the same direction as the jet. Vertically mounted jet fans installed in exhaust shafts have been successfully used to ventilate a large passenger rail overbuild in New York City. A comparison of shaft dimensions, vertical placement of the jet fans and measured shaft airflows is presented to evaluate optimum jet fan configurations. Measured shaft airflows are compared to airflows predicted by computational fluid dynamics (CFD) simulations of a three-dimensional model of the overbuild.

Sep 1, 2022

By Clarence A. Johnson

The discovery of the Prudhoe Bay field temporarily reduced interest in the development of coal conversion processes, but interest is being re¬newed by the current energy crisis. According to M.A. Wright, Chairman of the Board of Humble Oil and Refining Company(l), the reserve in the Prudhoe Bay bield has been confirmed to be about 10 billion barrels. At first glance this appears to be an extremely large reserve which will eliminate supply problems for the United States for some time. This feeling of security is lost when one realizes that by 1980 the world will consume the reserves of a Prudhoe Bay or a Libya, or Venezuela in less than a year, based on the recent predictions of U.S. and world reserves made by Eastman-Dillon, Union Securities Company(2). Recent forecasts of U.S. demand and source of supply made by Kenneth E. Hill of Eastman-Dillon are shown in Figure 1. This forecast shows a decline in domestic supplies (excluding Alaska) after 1973, with the total domestic supply leveling off in 1975 at about 13 million barrels per day. Since the predicted demand increases from about 14 million barrels per day in 1970 to about 20 million barrels per day in 1980, about 35% of domestic consumption must come from imports or non-conventional sources by 1980. More imminent is the shortage of low sulfur fuel oil which has been created by the new, tough air pollution regulations that are basically legis¬lating eastern coals out of the market. As an alternate to importing large quantities of low sulfur fuel oil or importing and desulfurizing regular fuel oil, one of two domestic solutions is possible: stack gas clean-up or solids fuel pretreatment. Stack gas clean-up may be the cheapest approach for old installations, but fuel pretreatment has real advantages for new installations. Coal pretreatment at the mine could eliminate all solids fuel handling

Jan 1, 1972

By Chris Roos

The mining industry has made strides in planning for operations to be safe for the workforce and public, to protect the natural environment, and to maximize value for shareholders. However, many of the techniques used to accomplish these goals are based on estimated models of mineral content, production efficiency, and economic performance. The industry has begun to recognize the need for understanding the uncertainty in these models, how it affects their decisions, and what the potential impacts are for each project. The challenge has become how technical professionals can effectively communicate the impact of this uncertainty and its importance to both technical and non-technical audiences. This paper presents mining engineers (and other technical professionals) with traditional and modern principles of data visualization and technical communication that can assist with communicating the effects of uncertainty in the mine planning process.

Jun 25, 2023

By Mike Wongkaew, Brandon Kluzniak, Per Vilhelmsson

Rail access to Ontario International Airport (ONT) has long been a goal of San Bernardino County Transportation Authority (SBCTA) to increase public transit options to ONT and provide incoming ONT passengers improved access to San Bernardino County and the greater Southern California region. This paper describes the planning for the Design-Build-Operate-Maintain (DBOM) delivery of an emerging technology tunnel connection between the Rancho Cucamonga Metrolink station and ONT. The paper discusses key technical considerations, challenges, and opportunities; conceptual configuration development; and construction planning and establishment of the footprint for the underground connection.

Dec 1, 2022

By Verne Huser

The intensity of environmental conflict, the delays and legal battles that have marked the 1970's suggest the need for additional processes to resolve environmental disputes. Our present means frequently fail to address the real issues separating individuals and institutions. They are primarily adversary processes that foster polarization and reduce cooperative efforts. At the Office of Environmental Mediation, we have no quarrel with adversary processes nor with polarization, for both serve as important spurs to necessary change. We do seek cooperation among parties at a point where there can be a realistic expectation of success in facilitating a resolution of their mutual differences.

Jan 1, 1979

By Michael P. Evans

Traditionally in coal processing jigs have been used to clean the coarse coal fraction, the +3/8" or +1/4" material. Today with the advent of modern fine coal jigs in the United States, its place was moved from the coarse to the inter- mediate coal circuit, the 3/8" x 100 mesh. The most economical coarse coal circuit to build and operate is a heavy media bath circuit. The following table summarizes the cost per raw coal ton processed for a coarse coal jig circuit, and a coarse coal heavy media bath circuit. The flowsheets used to compare these two circuits are shown in Figures 1 and 2.

Jan 1, 1983

By B. K. Parekh

The International Symposium on Comminution was organized at Camborne School of Mines, Cornwall England. Papers covered the fundamental and practical aspects of comminution in the mineral industry. Although comminution equipment design has not changed fundamentally during the last 50 years, methods of control and optimization have improved considerably. A simulation model for batch ball milling in the rotating mill was developed as a step toward continuous simulation of ball and autogenous milling. New concepts in jaw crusher technology design and the concept of a 1.6- x 2.1-m (66- x 84- in) jaw crusher with open feed throat has resulted in power savings. The use of cone crusher technology in comminution circuits with particular reference to machine design, plant flowsheet and control figuration has been reported by Boliden Allis, of Sweden. The Whiten steady state crusher model form has been used to develop a quantitative model of 2.1-m (7-ft) cone crushers. This was done by incorporating liner age (wear) and liner length as variables on the selection of particles for breakage and thus on the product size distribution. Another paper by Lira and Karetsky discussed the development of a model based on a multisegment ball mill developed by Whiten and Kavetsky. It is capable of simulating the performance of a coarse grinding ball mill of a given diameter, ball size and mill speed.

Jan 1, 1991

By R. Fred Pena

The Tower Mill has proven to be a grinding machine with a demonstrated application flexibility. Variations in applications have proven to be numerous. This mill was originally intended for fine grinding applications. Subsequent testwork and installations have demonstrated the mill can be utilized in place of ball mills as secondary mills. The following lists a few of the circuits tested: 1. Tower Mill secondary receiving feed from a primary SAG mill grinding stage. 2. Tower Mill as tertiary grind unit following a rod mill/ball mill. 3. Tower Mill as secondary grind unit following a primary ball mill. 4. Tower Mill as a limeslaker. 5. Tower Mill grinding as a primary unit taking limestone crusher discharge. Applications demonstrate the mill is energy efficient and is sensitive to the following consideration: 1. Circuit chosen. 2. Top size of feed. 3. Product size required. 4. Classification equipment performance. 5. Media size required. 6. Media type required.

Jan 1, 1986

By Charles H. Greene

This paper will describe briefly the steps taken in the development of a Central Florida phosphate ore deposit from acquisition to mining. Further, the design and early operation of the mining and beneficiation facilities will be depicted. During the 1950's, with confidence in the continually increasing requirement for phosphate fertilizer materials essential for producing food, I'. R. Grace & Cc acquired the Hookers Prairie tract containing approximately 45 million metric tons o. (50 million short ton~ of potential phosphate rock product. In 1973, at a point when the Grace captive need for rock was being greatly enlarged by a planned doubling of its Bartow phosphate chemicals plant capacity, the decision was made to expand existing phosphate rock production by building a new mine and plant. The initial annual capacity was to be 2.3 million tons (2.5 million st); however, subsequent investigation pointed to a higher than estimated dragline operating factor 'and the forecast of annual capacity was set at 2.5 million tons (2.8 million st).

Jan 1, 1977

By J. Sattarvand, P. C. Augustine

Despite significant safety improvements, the mining industry remains one of the most hazardous occupations globally and the evacuation of Miners, when an uncontrollable incident occurs in the mine, is the best bet to saving lives. However, Human factors/behaviors during an emergency are likely to influence the evacuation performance. Other industries have made a significant effort to determine these human factors that can impede evacuation performance, however, the current state-of-the-art in mine evacuation or self-rescue is that the evacuation route is predetermined, and a static sign is used to direct miners to the predetermined safe location. This method is limited in representing actual conditions that arise in a real emergency, neglecting the different behaviors displayed by humans. As optimization of the evacuation of a mine plays a fundamental role in emergencies and modeling evacuation behavior and movement of miners is a complex task, this research utilized Agent-Based simulations to simulate the evacuation behavior and performance. It was observed that people with the smart evacuation device made fewer mistakes and arrived at the safe place in less time compared to those have no access to the device. The Mathematical model used in optimizing the shortest path to a safe place is also explained in this paper.

Jun 25, 2023

By James C. Fowler

The use of ground-probing radar as a reflection mapping tool has expanded greatly in the last few years. This tool can now be used to produce near surface information which is very useful to geotechnical engineers. Using the lightweight field equipment now available, it is possible to use the radar within mines and tunnels to obtain information which may impact the safety and production of these operations.

Jan 1, 1979