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By John N. Murphy, Edward F. Fries

The availability of fast, low-cost computer hardware and advanced software is opening new opportunities for minerals extraction and processing. Programmable Logic Controllers (PLC's) are currently used extensively in the minerals industries; this paper looks beyond PLC's and that vintage of “computer control”--it looks toward what the authors see as new in the next five years. Topics covered include expert systems, neural networks, intelligent signal processing, and hierarchical controllers as applied to mining and mineral processing operations.

Jan 1, 1993

By William G. Fischer

Basic laboratory tests initiated the. Rock Mechanics program. The stress-strain curve, modulus of elasticity, Poisson's ratio, the uniaxial rock strengths, Mohr's envelope, the stress at failure, and creep were investigated. A series of underground problems were then approached using this information; and various field measuring devices, most of which were developed by the Bureau of Mines. Initially, stress concentrations near mine openings were evaluated using the stress relief technique. This required an accurate determination of the pre-mining stress field. Later, stress concentrations associated with the cave line .sere studied. After about thirty stress reliefs over an appropriate time interval the effects of one type of mining could be compared against another. The microseismic technique was used to investigate a possible application of warning devices near the cave line. A study of mane reorientation was made Problems related to the shape and size of pillars and barriers were studied. Partial extraction mining systems were evaluated. The effectiveness of roof bolting patterns were examined. Control of roof stresses was attempted. A new system of mining in heavy ground has been developed using the information secured in the Rock Mechanics program without this system, mining in more than one instance would Nave been next to impossible. Indeed; from this one discovery alone, the Rock Mechanics program has paid off in improved safety as well as in dollars.

Jan 1, 1964

By James W. Collins

The bucketwheel stacker/reclaimer is suited for a variety of bulk material handling systems, especially those operating with stockpiles in excess of 30,000 tons. The bucketwheel stacker/reclaimer, although relatively new in the United States (first introduced here in 1964), has been successfully used in European countries since the early 1940's. Basically the machine is the outgrowth of the bucketwheel earth excavator and the traveling tripper boom type stacker. Since their introduction here they have achieved wide acceptance, especially with coal fired power plants. (Figures 1, 2, and 3.) The stacker reclaimer has been utilized in barge and ship loading/unloading facilities, and in the material handling systems for steel mills, where it has been used to stack and reclaim iron ore at rates up to 6000 tph stacking and 4000 tph reclaiming. They have also been employed at mine mouth power plants for the handling and storing of the plant fuel supply and to help balance the mining rate with the fuel consumption rate.

Jan 1, 1973

By P. R. Taylor

A review of the advantages and disadvantages of plasma technology for metal and mineral wastes is presented. Examples of the use of plasma systems are given and possible future uses are outlined. Among the potential uses are treatment of electric arc furnace (EAF) dusts, the vitrification of nuclear wastes and the removal of toxic metals. Over the past few decades, plasma technology has been studied for potential applications over a wide range of metals/materials processing areas. One promising area of plasma technology applications is the treatment of industrial hazardous waste. The potential generation of hazardous and toxic waste by various industries has become a matter of public and political awareness. Environmental regulations have put stringent toxicity emission limits on disposable waste streams. An intensive research effort is currently underway in the area of hazardous waste treatment.

Jan 1, 1994

By A. H. Brisse

In considering the use of a coal or a coal blend for the production of metallurgical coke, the fact is often overlooked that laboratory data can be most effectively used to determine coke plant operating conditions conducive to maximum output as well as to predict the quality of coke produced. The discussion here presented attempts to point out the manner in which carbonization data can be interpreted for industrial use and the significance of specific laboratory test results in this interpretation. The major considerable must, of course, be the safeguarded of coke oven batteries, against wall damage arising either from excessive carbonization pressures or from the wedging of the pushing ram into non-contracting coke charges. In order to be specific in the matter of handling the laboratory data involved, two series of blends are analyzed. The first of these, referred to as the "AB" series, is typical of some d' the more highly expanding Eastern- coal blends whereas the second series, here referred to as the "CD" series, is probably more typical of the Western coal blonds. Reference to Table II should be made for rank of coals considered in these blends.

Jan 1, 1959

By W. Zitz

Incorporation of heat exchangers into drilled shaft foundations is a novel approach to both improve the energy efficiency of building heat pump systems and provide necessary structural support using the same construction materials. In an effort to quantify the structural and heat exchange performance of deep foundations used as ground-source heat pumps, two instrumented test foundations were constructed as part of a new construction project in Denver, CO. They will be integrated into the conventional ground-source heat pump system for the building. This paper focuses on the lessons learned from the construction process for these energy foundations.

Jan 1, 2011

By Steve Rogers

Nautilus Minerals was listed on the Toronto Stock Exchange in May 2006. The company now has major mining companies Anglo America (5.7%), Teck Cominco (7.2%) and Epion Holdings (22.4%) as significant shareholders, and has raised approximately $US346 million dollars to develop the world's first deep-water mine. The company is currently targeting high-grade copper and gold in seafloor massive sulphide mineralization, located near plate boundaries in back-arch basins of the Western Pacific. The first mine scheduled to be developed by the company is located in 1,600 meters of water at Solwara 1, in the relatively quite waters of the Bismarck Sea approximately 50 km from the port of Rabaul, within the Territorial Waters of Papua New Guinea. During 2006 and 2007 the company completed detailed environmental and geological studies, culminating in a number of world firsts, including the world?s first NI 43-101 compliant resource statement and environmental impact study for a seafloor massive sulphide system. Permitting is well advanced for the project, with initial production scheduled for late 2010, subject to timely grant of the permits. Extensive government and stakeholder liaison and engagement has been undertaken throughout the projects life, and is a core feature of Nautilus' desire to "do it right" in all aspects of this new industry.

Jan 1, 2008

By John D. Price

The solution to the problem expressed in the title of this paper might well be condensed into one word, AUTOMATON, But if I were to stop there, even though most of you might applaud, I am afraid that a one-word paper might not justify my coming to this meeting, So let?s explore the matter and try to learn if and to what extent the science of automaton can be applied to the problem of coal cleaning. In taking this approach we must, of course, by-pass the fact that plants In this Country and aborad have been automated to a greater or lesser extent. We will explore the matter from the beginning and not merely take the approach that because others have done it we can do it also. First, let us see just what is meant by automaton.

Jan 1, 1959

By R. Jin

The hydrophobicity of six coals ranked from lignite to anthracite is studied through contact-angle measurements, bubble attachment-time measurements, FTIR spectroscopy, and Hallimond-tube flotation. The preliminary study shows that the hydrophobicity of coals can be told by the bubble attachment times of coals (a kinetic criterion) or by the contact angles (an - equilibrium criterion). A general agreement between flotation response of coals and measured bubble attachment times or contact angles is observed in the present study. However, the study also shows that the hydrophobicity of coals can be predicted by FTIR spectroscopy work with proper manipulation of the spectra. Both hydroxyl and carboxyl groups in the coals are proven by FTIR work to be responsible for the change of coal hydrophobicity. A new criterion for the hydrophilicity index of coals from FTIR spectra is introduced through the study.

Jan 1, 1987

By James E. Friant

The technology applied to shaft sinking has lagged far behind other construction activities. While surface oriented construction and mining have made great strides with new processes and equipment, the majority of shafts sunk currently still follow a drill, blast and muck-out cycle developed in the 16th century. Today, in 1979, the shaft sinking industry is in the midst of its own private industrial revolution. Millions of dollars are being spent annually by industry and government alike to spring the art of shaft sinking into the 20th century. The objective of this paper is to review a few of the newest mechanized schemes for shaft sinking. This is not a theoretical review, however, but a practical one, and deals only with hardware and projects which are currently on jobsites. Figure 1 shows the equipment. On the left is the 241SB 184, a 24 foot diameter blind shaft borer. This machine is currently at about 200 feet, constructing a coal mine shaft in Alabama. It is built and utilized in a manner similar to a tunnel borer. In the upper center is the 1211SR, a 12 foot diameter blind shaft reamer. This machine follows a 6 foot pre-drilled blind pilot hole, and is at work in Chicago. On the upper right is the 121BR, a powerful new blind drill. Just below it is the conical drill head for the 121BR which can utilize either carbide or standard disc cutters. At the center bottom is an expandable back reaming head which can be used to enlarge a drilled shaft up to a maximum of 16 feet diameter, or can be used to produce a shaft having several diameter changes. This equipment is also in use in Chicago.

Jan 1, 1979

By B. Kolonja

This paper considers simulation of truck dispatching system designs using maximum expected production of the truck-shovel system as the measure of performance. Two methods are utilized, multiple comparisons with the best (MCB) and the combination of MCB and the variance reduction technique known as common random numbers (CRN). These two techniques are compared via simulation experiments. The results show that the combined procedure of MCB with CRN is the superior tool to reduce the total number of replications needed to ensure the specified probability of correct selection over the finite number of designing systems. In this case study, MCB with CRN reduces the variance by 29% and the number of required replications by 48%. Also, the MCB with CRN procedure narrowed the confidence interval by 18%.

Jan 1, 1994

By Warren N. Warhol

The mutual growth of the rare earth industry and the Mountain Pass Operations was no coincidence. It was the commercial availability of rare earths on a scale first made possible by the capacity of the Mountain Pass Operations that spurred research and development efforts toward new applications for rare earths. The first important demand on Mountain Pass was europium oxide for the activation of red phosphor for color television tubes in 1964. Since that time, other rare earths have become even more important, and Molycorp is continuing to supply an ever widening variety of rare earth concentrates and compounds. We enjoy saying that rare earths are not really rare, and that they are not earths, either. Of course, we are talking about the 15 metallic elements with atomic numbers 57-71, called the lanthanides, which occur in nature always together in very similar proportions. Their scarcity can be gauged by the fact that there is more cerium in the earth's crust than there is tin, and more europium than cadmium. The word "earths" comes from the early chemical term for oxide. The rare earths were discovered as oxides, and the term has persisted.

Jan 1, 1980

By Robert L. Grayson

In small coal mining operations, little is done in controlling supply and material inventories and optimizing total inventory costs. Material Requirements Planning (MRP) is an efficient material control system which time-phases net material requirements based upon production plans, bills of material data, and inventory status records. Inventory levels and total inventory costs are optimized using a lot sizing technique in placing time-phased purchase orders. The MRP system has been applied in large manufacturing firms utilizing mainframe computers, but it can be adapted to micro-computers for inventory control. This paper presents an application designed to assist the coal mine manager in optimizing inventory costs.

Jan 1, 1985

By Clifford J. Lewis

The role of calcareous minerals in that area of the environmental improvement program involving the control or elimination of sulfur oxide emissions is discussed, and a new concept in gas scrubbing, rendering possible the use of calcareous rocks more extensively for this purpose, is presented. Calcareous rocks are defined as the more common limestones, consisting essentially of calcium carbonate and magnesium carbonate. The effect of magnesium carbonate on the reaction rate of limestones and lime toward sulfur oxides in aqueous scrubbing systems is pointed out. The relative economics of lime- stone versus lime as aqueous scrubbing reagents for sulfur dioxide are indicated.

Jan 1, 1974

By Evan Adams

The Ireland Mine is located some seven miles South of Moundsville West Virginia, along the bank of the Ohio River. We are mining the Pittsburgh #8 seam. This seam is approximately 60" in thickness, and is immediately overlain by some 10 feet of a conglommerate material. The roof is difficult to control, due to the fact that it frequently is composed of substances not hard enough to be held together with 6-foot roof bolts. In many cases, we must use 10-foot roof bolts, in order to get bolt anchorage in the limestone above the conglommerate. Due to the elasticity of the limestone and its tendency to bend rather than to break, we have been unable to maintain a pillar line. Thus, we have found it necessary to mine by the room and pillar system. Belt haulage is used on room entries to automatic loading stations, thence into 15-ton mine cars, controlled at the loading point by car spotters. The maximum belt length is 2,000 feet. Rail haulage to the slope-bottom dump is by 27- and 50-ton locomotives. The mine produces coal two shifts per day, with 7 production crews on each shift. Mine and machinery maintenance is performed on the Midnight shift. We handle an average of 660 tons per machine shift.

Jan 1, 1964

By T. J. Durbin

At some surface and underground mines, control of ground-water inflow involves significant costs. These costs include the capital costs for installing a dewatering system, power and other costs to operate and maintain the system, and costs to treat and dispose of the water that is collected. To minimize these costs, design of a dewatering system utilizing wells has been formulated in terms of a nonlinear operations research problem using quadratic programming. Using this formulation, the locations, depths, pumping rates, and pumping schedules of wells are selected so as to minimize the total costs of the dewatering system.

Jan 1, 1993

By G. C. Tipper, A. P. Deane, A. G. Myers

SCHEME DESIGN London’s Heathrow Airport, as the world’s busiest international airport, is missing one vital aspect - a dedicated rail link which connects directly to the city. All this is about to change with the construction of Heathrow Express - a fast, high quality rail service between the airport and the centre of London. It was recognised in the mid 1980s that if Heathrow was to accommodate the forecast growth in passenger numbers and the resulting increase in road traffic, a dedicated airport rail service would be vital. The main access into the centre of Heathrow is via a road tunnel with a direct link to the M4 motorway. The airport has introduced a number of traffic management schemes, but these can only achieve so much benefit. Growth in air passenger traffic is predicted to continue at an average of 4% per annum well into the next century and it was clear that significant investment was needed. Heathrow Express at a cost of over £350 million will provide this when it starts its service in June 1998. The business case for the scheme is based on a rider ship of around 15% of air passenger traffic. The initial Heathrow Express service will be based on four trains per hour, up to 8 car train lengths, providing a high speed non-stop service between the airport and central London in just 16 minutes. Initially a joint venture between the British Railways Board and Heathrow Airport, by mutual consent of the two parties, Heathrow Airport recently purchased the British Railways Board share making this one of the largest private sector rail projects currently under construction in the UK. Leaving Paddington, the main rail terminus in West London, Heathrow Express trains will travel 12 miles on the newly electrified line to airport junction, north of the airport. At this point they will leave the mainline to enter a 5 mile tunnel section that runs underneath the heart of the airport. The railway companies are responsible for track work, signalling and electrification of the 12 mile main line section including a grade separated junction over the main tracks for the Great Western Railway which links London and South Wales. Heathrow Airport is re-

Jan 1, 1997

By G. J. Olson, K. S. Noah

A combined physical/biochemical process for the precombustion removal of 13 inorganic hazardous air pollutant (HAP) precursors, i.e., Sb, As, Be, Cd, Cr, Cl, Co, F, Pb, Hg, Mn, Ni and Se, from coal was tested. Biochemical processes for removal of HAP precursors from coal potentially offer advantages of deeper cleaning, more specificity and less coal loss. The slurry column is a second-generation process for the beneficiation o f fine (60-mesh x µm coal by a combination of physical separation of mineral matter and biooxidation of pyrite. Sixty-seven percent removal of pyrite from a 60-mesh Pittsburgh #8 coal was achieved at a 35% (w/w) slurry concentration and a five-day reactor residence time. Ninety percent of the heating value of the feed coal was recovered. Among the HAP precursors of most concern, over half of the Se, As and Hg were removed from the feed coal. From 40% to 70% of most HAP precursors were removed from the feed coal. Hg in the feed coal was reduced from 0.12 to 0.054 ,µg/g in the product coal, while waste coal contained 0.24 µg/g.

Jan 1, 2000

By J. C. Yingling, R. Kumar, J. Sottile

The capability for on-line measurement of the quality characteristics of conveyed coal now enables mine operators to take advantage of the inherent heterogeneity of those streams and split them into wash and no-wash stocks. Relative to processing the entire stream, this reduces the amount of coal that must be washed at the mine and, thereby reducing processing costs, recovery losses and refuse-genera¬tion levels. In this paper, new ap¬proaches for optimal control of the segregation process using time-se¬ries models and empirical distribu¬tions are presented and demon¬strated using field data.

Jan 1, 2000

By Lee S. Richardson

Silicon is usually considered to be a useful metallic alloying element. To be more truthful, it is not a metal at all, but a semiconductor, whose electrical resistance (when pure) is high and decreases with temperature. We will join the metallurgists, at least for this paper, and refer to it as a metal. In its commercially available form, silicon is metallic in appearance, brittle, with a density of 2.33, less than that of aluminum. Silicon dioxide or quartz has a high heat of formation, which not only makes the metal a useful reductant for other materials, but also makes it difficult to reduce from its ore. The melting point is 1412°C, slightly less than steel, but substantially higher than aluminum or cast iron. The alloys of silicon with iron, usually called ferrosilicons, have some unique advantages. The melting points of most alloys are substantially below those of iron or silicon (Fig. 1). The two major compounds formed (FeSi and FeSi2) help somewhat in the reduction of silicon by their energies of formation, but the influence of these phases on the mechanical properties is more important. Four major groups of alloys are made -- silicon metal (>95% silicon), 75-85% ferrosilicon, 50% ferrosilicon, and silvery pig iron (12-22% silicon). The alloys between 50 and 65% silicon and between 25 and 40% silicon are normally avoided because of structural instabilities, presumably of the two compounds, leading to disintegration of the alloys on cooling.

Jan 1, 1974