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By James D. Cooper

Long range projections of demand for nonmetallic minerals are presented, together with data on the domestic resources which are available or which can be made available to meet the requirements through the balance of the century. Past successes in solving nonmetallic mineral requirement problems are briefly reviewed to illustrate the capability for solving present and future problems of a similar nature. Major problems threatening the future supply of specific industrial minerals are described together with possible methods for assuring the necessary raw materials for future needs. The growing importance of environ- mental degradation, land use conflicts, and other important factors which affect several or all of the nonmetallic mineral industries is covered, and the necessity of planning for efficient and orderly extraction and rehabilitation of mineral deposits is stressed. The present Bureau of Mines methods and tools for long range planning are briefly discussed.

Jan 1, 1969

By Carlos Tarazaga

Progressive Design-Build (PDB) is an emerging variation of alternative delivery programs in the underground construction industry. PDB refers to the way a construction project design is developed by the Owner and the Design-Builder in a step-by-step process. According to the Design-Build Institute of America (DBIA), Progressive Design-Build allows the design and construction team to collaborate during the earliest stages of project development. This enables engagement between the three key players in a construction contract: the owner, the designer, and the contractor. Is the PDB the best alternative program delivery for large contracts? What is the perspective of the private sector? This paper will provide an overview of the different alternative delivery programs used in the underground industry, pros and cons of each of programs, and the perspective of the designers and contractors. The paper will focus on how the PDB works, reasons why owners should consider PDB for their projects, best collaboration strategies among owners, designers, and contractors to deliver a successful project, and how to manage the project risks using a PDB method.

Jun 13, 2023

By P. R. Taylor

Batch leaching experiments have been performed to study the kinetics of galena leaching in fluosilicic acid solutions with oxidants. Variables studied included: fluosilicic acid concentration, oxidant type, oxidant concentration, particle size and leaching temperature. It was found that hydrogen peroxide was the most effective oxidant, compared to the others studied, and the effect of the oxidant concentration on the leaching behavior of galena was very significant. Also, decreasing the particle size and increasing the leaching temperature increased the extraction rate. The initial, apparent activation energy was calculated to be 11.72 kJ/mole (2.8 kcal/mole) and suggested that galena leaching in fluosilicic acid solution, with hydrogen peroxide as an oxidant, may be controlled by fluid film mass transfer initially. The reaction appears to be retarded by the formation of elemental sulfur and the sulfur oxidation becomes a major resistance to the overall leaching reaction.

Jan 1, 1992

By R. Venkataramani

Crushed stone operations have become more difficult due to rising costs of labor and equipment, with the consequent reduction in profit margins. Competition from other operators and the encroachment of vertically integrated companies place severe restrictions on available markets. The seasonal demand for stone precludes any definite production level, and changes in productivity have to be accommodated. These influence profitability, and therefore production plans must be continuously adjusted to keep pace with rapidly changing conditions. The basic problem of stone companies seeking to maximize profits is one of balancing stone production costs, costs of inventory holding and stock-piling, marketing costs and any other charges accruing over time against the selling price of stone. Because of high peak demands, slack period production must be stored and then distributed to supplement peak period production. For a multi-plant operation, there is a need to evaluate at the same time the interaction between the plants and the various marketing sectors. In a multi-plant operation with different production capacities and production costs, stone producers are interested in the answers to the following questions: 1. How much stone should be produced at each plant in each time period? 2. What should be the optimum stone shipment from each plant to each market? 3. What are the effects on net returns and shipping plans, if production capacities are altered at the plants? These questions have many different answers that, will satisfy demands. From the point of production scheduling, the minimum production cost may be the objective. From the inventory standpoint, the best solution will be to synchronize production with sales. However, when the transportation of stone is also considered, the desired end is to achieve that delivered cost which maximizes the company f s net return. Besides, only an extremely naive analysis ,wouId attempt to

Jan 1, 1971

By M. Xing, S. Usman, K. Awuah-Offei

"While mines generally focus on achieving operational efficiency, creating shared value for all stakeholders is also a management goal. This includes taking a holistic view of their supply chains and increasing local participation. This paper examines the role of supply chain management in mine management; in particular the effect of a strong local supply chain on regional economic impacts. Using input-output analysis, the impact of a local supply chain on a mining sector’s regional economic impact is examined by increasing local sourcing (increasing local purchase percentage -- LPP) for 10 key commodities. An approach, based on multipliers and excess local capacity is used to identify key commodities. The impacts examined are sales, employment, labor income, and value added. The work is illustrated with stone mining and quarrying in Missouri. Ten percent increases in LPP of the key commodities, in this example, result in $4.1 million additional impact on the Missouri economy. This work can provide insight on how to better create shared value for all stakeholders. INTRODUCTION Little research has been published on improving mine supply chain management (SCM) to enhance regional economic impacts. Although some extensive academic research has explored the importance of an industries’ supply chain, not much is known about how a locally-based supply chain increases shared value in the resource sector. Across industries, traditional SCM is getting more and more complex. This is true of the mining sector as well. However, this increased sophistication is not directed towards increasing shared value for all stakeholders, particularly, the local communities. Further research is required to develop new SCM strategies that enhance local participation. One major point of difference between this work and traditional supply chain management is the inclusion of stakeholders’ shared value as a goal in SCM. Creating shared value has become a business goal in recent years (Porter and Kramer, 2011). The authors use input-output analysis (Leeuw, 2012) to evaluate the regional economic impacts of supply chain decisions, which is not part of traditional SCM. Although input-output analysis has been applied to SCM for decades, most of the research uses input-output analysis as a tool to advance an industries’ own operational efficiency (Accenture, 2014)."

Jan 1, 2015

By Edward T. Koch

With the dramatic increase in world demand for basic raw materials, open pit mining is proceeding at an unprecedented rate. A viable demand is the ever tempting Siren's song for increased production or new facilities. When the Siren's lure is viewed against the panorama of today's world economic milieu the concomitant Scylla and Charybdis are seen in the form of high capital cost and high operating cost. If the economic realities of present day open pit mining are to show a proper return on investment, a clear and penetrating eye must be cast upon the area of mine planning. This paper deals with the problem of overburden removal. In almost every open pit mining operation overburden removal is a significant part of the capital cost and operating cost of the total operation. This paper deals with a new and unique method to affect economical overburden removal. Well known to all are the parameters surrounding draglines, shovels, and bucket wheel excavators. All of these machines require a reasonably stable soil to support them and the shovel and bucket wheel excavator require a reasonably stable bank in which to operate. Their reliability, portability and rate of production per dollar of invested capital are good.

Jan 1, 1975

By Y. Guan

The adsorption of zinc species onto silica in ammonical solutions has been studied. Adsorption isotherms reveal that increasing adsorption occurs as the solution pH is made more alkaline. Fr-IR spectroscopy revealed that the adsorbed species is a zinc ammine complex.

Jan 1, 1993

By Delbert L. Keenon

The principal concepts of computer control and automation have been successfully applied in industries world-wide, The enthusiasm generated by the proponents of computer control, and the apparent mystery enveloping the techniques of computer control, have caused attention to be focused on this infant industry from all quarters. Consequently, the motivation to "computerize" may be the hope that computers will solve all economic problems. The truth remains that not only have there been monumental successes, but there have been some colossal failures. This paper will attempt to outline a generalized guide to computer control and present methods for avoiding some of the major pitfalls. Since the investment required for computer control systems has been drastically reduced in the past year, small operations will likely find that computerized process control is attractive in areas where it has never been considered before, The discussion presented here is intentionally non-technical and directed towards those who may soon find they have a possible application for a control computer. The primary purpose of computer control is to reduce expenditure and increase profits by improving the quality of product, increasing the efficiency of operation, reducing the materials and man hours required or a combination of these. Success or failure to reach the desired goal depends, to a large degree, on a well-planned approach. This includes recognizing a possible computer application, properly defining the job which is to be accomplished, evaluating computer systems, selecting a capable manufacturer, and following through with sound systems engineering and programming.

Jan 1, 1965

By A. J. Naldrett

Over the past six or seven years important new ideas have been developed concerning the origin of nickel sulfide deposits. To a large extent these have been stimulated by the major nickel discoveries of the Eastern Goldfields area of Western Australia (Woodall and Travis, 1969; Ewers and Hudson, 1972). Prior to these finds, the most important nickel camps were regarded as being associated exclusively with intrusive rocks such as the Nickel Irruptive at Sudbury or the intrusive peridotites at Thompson, rocks that were thought to have no close association with volcanism. Study of the Australian discoveries, coupled with work in South Africa (Viljoen and Viljoen, 1969) and Canada (Naldrett and Mason, 1968; Pyke, Naldrett and Eckstrand, 1973), has shown that volcanic rocks with true ultramafic compositions and extrusion temperatures of 1400 to 1600°C were a common feature during the Archean. Under certain circumstances economic concentrations of nickel sulfides have formed from these rocks, either settling to the base of their associated flows or accumulating in shallow intrusive feeders to the flows. The aim of this article is to show how these ultramafic rocks can be recognized, how the nickel deposits, if present, are likely to occur within them, and what special features characterize ore-bearing examples of the rocks.

Jan 1, 1975

By J. L. Carr, A. K. Smith, C. C. Jobes, G. T. Homce

"Underground continuous mining machines pose a difficult safety challenge since their operators generally work in close proximity to these machines in very restricted spaces. Intelligent software for use with magnetic proximity detection systems has been shown to accurately locate workers around mining machinery in real time. Calibrating these systems requires the manipulation of a lot of data to determine the calibration constants. Researchers have developed software to analyze, convert, and visualize data acquired during this calibration process to more accurately model magnetic fields and their interaction with the environment. This paper details the background, development, and operation of the resulting application software focusing on the utility of the graphical user interface to visualize the magnetic field calibration data. The refined data developed by this process can then be utilized by the proximity detection system to more accurately identify the location of miners working in an underground mining environment. INTRODUCTION Roughly half of the electricity consumed in the United States is produced with coal, and roughly one-third of all US coal production comes from underground mines [1]. Over the last century underground mining health and safety has seen a continuous and dramatic improvement. However, machine-related injuries and fatalities continue to be a major safety concern [2]. Every year, hundreds of miners are severely injured while operating underground mining equipment, and 39 miners have been killed in striking/pinning accidents involving continuous mining machines (CMMs) since 1984. CMMs, such as the one shown in Figure 1, are large mobile machines that are used to mechanically cut coal in an underground mine. These machines weigh approximately 40 to 50 tons, have hydraulically articulated appendages, and are capable of moving at speeds up to six feet per second [3]. Modern CMMs are remote-controlled, yet the operator and other miners are often in close proximity to the machine. Recent research by the National Institute for Occupational Safety and Health (NIOSH) reveals that the locations workers take relative to the CMM are usually influenced by visibility requirements and safety concerns [4]. The Mine Safety and Health Administration (MSHA) estimates that at least 28 fatalities involving CMMs since October of 1984 may have been prevented with proximity detection technology [5]. MSHA further estimates that proximity detection could prevent 20% of all deaths throughout the industry [6]."

Jan 1, 2016

By M. D. Ross

Complex combinations of technical, economical, safety and environmental factors are causing mining engineers everywhere to review their operations. Naturally, some of the traditional methods still have a large role to play because they are, in certain circumstances still adequate and are well understood. But, as circumstances change, a new approach is required. The combination of technical and economical reasons for introducing Long- wall mining in some seams in the United States is associated with strata control. Other reasons include simplifications and improvement of ventilation, reduced coal dust, more output from each unit and crew, increased percentage of recovery from each area of the coal deposit, and reduction of rock dusting. The innovations which transformed Longwall mining from a cyclic to a continuous mining system were the armored conveyor and power loading machines, but the crucial breakthrough for application to high production was the development of the powered roof support, which at once gave the system the advantages of mastery of strata control, increased rate of advance, significant reduction of manpower, and increased safety.

Jan 1, 1974

By Glenn J. Phillips, Debra L. Musick

The operating mine is dynamic, everchanging, and a continuous moving target. The only way to effectively manage such a creature is to be able to evaluate the cost of operation over short enough time periods that rapid effective controls can be implemented before loss can erode the marginal profits in todays market place. Such short term evaluations can provide the basis for the long range planning that can keep an operation healthy in the future. The spreadsheet programs on small computers (PC's) offer the possibility of such evaluation by accumulating data in a useable format, providing timely cost reporting and providing a tool for use in evaluating the day to day alternative choices of the real mining world.

Jan 1, 1987

By Don Rose

Steel-fiber-reinforced-shotcrete (SFRS) methods of testing and the wording of specifications vary from country to country. In the USA ASTM C1018 is widely used. The Canadians have taken a close look at C1018 and point out that exact determination of the first crack is very subjective, and they propose a method of design that eliminates this variable. The Europeans (EFNARC) have taken the principles of testing a step further than ASTM C1018, and have added a new step in measuring the effectiveness of SFRS. EFNARC uses an "energy absorption" of a plate loaded in its center, in addition to the principles of C1018. The principles of SFRS design are also used in Japan, Norway and elsewhere.

Jan 1, 1999

By Keith G. Wallace

The effect of face resistance on ventilation air leakage through stoppings was measured in a twin development heading. Face resistance was varied by alternately tightening or loosening the face line brattice to change the line brattice leakage. Results indicated that tight brattice lines are necessary to maintain acceptable airflow at the face but result in higher leakage throughout the entire system, reduced overall ventilation efficiency, and higher operating costs. Conversely, a low face resistance which simulated an auxiliary fan/duct system gave reduced stopping leakage losses, higher quantities of air at the last open cross-cut and greater entire system efficiencies

Jan 1, 1984

By D. B. Sikka

Porphyry type copper ± molybdenum deposits typically occur in the Phanerozoic rocks and have been well documented. During the past two decades a number of porphyry type Cu ± Mo deposits which range in age from 1055 ± 35 Ma to 2970 Ma have been identified in the Precambrian rocks of Australia, Canada, China, Finland, India, Namibia and Zambia. Kalanjkhand porphyry copper deposit M. P., India which is estimated to contain 789 million tonnes averaging 0. 83 percent Cu (millhead-grade); 0.004 percent Mo; 0.2 gm/t Au; 6 gm/t Ag and a cap of 7.532 million tonnes of oxide are averaging 0.8 percent Cu. The economic potential of the expanded copper mining milling, smelting and refining complex to be built in the future at Kalanjkhand, which is the largest porphyry copper deposit discovered to date in the Precambrian rocks of the world is presented.

Jan 1, 1992

Placing a detonating explosive inside a volume of rock is an efficient method of rock fragmentation. The explosion generates internal tensile stresses in the rock, and because rock is a brittle material, this brings about crack propagation and fragmentation far more efficiently than does application of explosive on the surface. To get the explosive inside, we drill a pattern of boreholes and charge the explosive into the holes. This is really the one and only purpose of making blastholes in mining: to give access for the explosive to the interior of the rock. No matter how big and expensive a drilling jumbo we stand up in front of a rock face, and no matter how many boreholes we let it drill, the rock does not fall apart by itself without blasting. It is the action of the explosive in the boreholes that does it. When we consider that we need a pound or two of explosive for every cubic yard of rock to be fragmented, and a pint of borehole volume for each pound of explosive, we see that the process of blasthole charging is an important element in the whole process of rock blasting.

Jan 1, 1975

By George M. Meisel

This paper is devoted to a discussion of the factors governing design of concentrators for large grinding circuits. Emphasis is placed on the manner in which use of ever larger grinding mills has affected the size of grinding bays, service cranes, gear reducers and electric motors, and the selection of ancillary equipment for cushioning of the starting load of large mills. Information is presented on the effect of using large grinding mills on the capital and operating costs of concentrators, e. g. : (Fig. 1) ? Benefits in lower cost of mills, drives and materials handling equipment, plant space, power, grinding media, operating labor and maintenance, and in ease of instrumentation and automation. ? Penalties in distribution of materials from the grinding mills to multiple lines of equipment which have not been developed to commensurately large sizes, and higher cost of ancillary equipment.

Jan 1, 1968

By T. E. Wilson

The length of Alaska's coastline, combined with the presence of a significant number of fjords, encourages consideration of marine disposal of mine tailings. However, the decision-making process is complex because various factors govern the viability of the submarine tailings disposal (STD) option. An expert system, called the Submarine Tailings Disposal Expert System (STADES), was developed to help mining project planners explore the feasibility of STD. A review of the existing literature, supplemented by engineering recommendations, on the various aspects of the marine disposal of tailings formed the knowledge base for the expert system. The shell used to develop the expert system was LEVELS.

Jan 1, 2003

By John C. Cook

There is pressing need for better means of exploring ground conditions ahead of mining. Exploration drilling has the drawbacks of high cost and a seriously restricted sampling zone. Traditional geophysical exploration methods including gravity, magnetic and resistivity techniques have been used with some success underground, but all give poor target delineation relative to range, since they depend upon minor distortions of a potential force field. Much greater ratios of resolution to range can, in principle, be obtained by employing electromagnetic or seismic radiation as the exploring agent. This is because propagation time delays can be used to measure range accurately, and to separate the small effect of a distant target from the much larger effects of nearer targets and of the transmitter. Seismic waves have long been used with great success in exploration for petroleum, and recent research on their application underground is promising. Electromagnetic (radar) waves have been very successfully used for detection and location through the air and outer space, and have also explored through polar icecaps more than a mile thick.l It is not generally realized that below the soil many rocks are also somewhat radar-transparent, and that radar can be used for exploring such rocks, once a quarry, a mine, a borehole, or other means of access has been opened. Radar waves are reflected by any boundary or object where they encounter a large change in electrical properties.2 The usual cause of such a change is a difference in moisture content. Radar waves passing

Jan 1, 1972

By R. L. Loofbourow

Most wet mines face unquantified water costs as well as the obvious wing costs. Both kinds of cost are multiplied by work at greater depth and by higher unit prices. This intensified challenge merits renewed or perhaps altogether new response. Any practicable way to reduce inflow tackles both obvious and unquantified costs. Ten groups of possible ways to do it are cited. Most have been demonstrated. Two are known from work other than mining. Surely new means can be found. Here are opportunities for operators of wet mines!

Jan 1, 1980