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Application of flotation for the removal of hydrophobic compounds from soils was studied. Bench scale flotation tests were conducted on artificially contaminated soil, using both conventional mechanically agitated machine and flotation column. Flotation parameters tested include surfactant collector type, conditioning time, flotation time, surfactant dosage, pulp pH, solid/liquid ratio in conditioning and pulp temperature. It is found that with conventional flotation 74% removal of the contaminant was achieved from soil particles in the range of 75-830 µm; with column flotation up to 80% of oil could be removed from the 250-830 µm soil fraction, and 65% from the 75-830 µm fraction. Flotation was found to have considerable potential for cleaning up contaminated soils.

Jan 1, 1998

By J. Réal Cloutier

[Options are a natural extension of the forward and futures markets as they offer fexible method of hedging exposure. -An organized options market is preferable to the "over the counter forward markets since EGCC (EOE, ME, VSE) assumes responsibility for contract fulfillment minimizing credit risks by guaranteeing transactions. -Options ante considerably more "fexible" than the futures and forward markets, permitting prompt, precise and respected adjustment of one's exposure risk position. -The risk to the buyer of the options market is limited to the initial premium paid.]

Jan 1, 1983

By B. C. Haydon

Manganese silver ores are well known to be refractory towards cyanidation. Various processes have been suggested for improving the amenability of these ores. A sulfurous acid pre-leach is one such process. This paper traces the development and implementation of the sulfurous acid pre-leach process for the retreatment of manganese silver tailings at Tonopah, Nevada. An account of the test work program is presented, followed by a description of the operating plant and specimen metallurgical performance. The paper also summarizes the history of the Tonopah tailings, their mineralogy and makes reference to previous application of the sulfurous acid pre-leach process.

Jan 1, 1984

By Cleland N. Conwell

The term "tender tundra" is a myth---a well-developed myth, but contrary to the fact. Any area that supports herbivores must have a plant base to supply food, In Alaska, herds of caribou migrate and live north of the Arctic Circle. And, if there is enough growth in the moss and lichens and arctic grass to support a caribou herd, the "tender tundra" can heal after it has been disturbed by mining. Another myth is that Alaska is an ice box. Actually, many areas In the state---particularly the Interior---have a high agricultural potential. Nevertheless, the fact remains: whether it is reclaimed by advancing the productivity from forest to agriculture or is allowed to remain a wild-life habitat, Alaskan land will revegetate. Reseeding speeds reclamation, but left to nature, native species will reclaim the land whether it was disturbed by forest fires, roads, villages, or mining. In fact, it is impossible to find many of the old gold mining camps.

Jan 1, 1975

Computerized financial models can be used in all phases of the mineral industry from setting exploration targets to projecting profit plans for producing mines. In this presentation, I will use the example of an exploration company entering a new district to trace the application of financial models through the following intermediate phases. 1. Hypothetical analysis and strategy 2. First encounter of mineralization 3. Preliminary drill results - decision process 4. Feasibility studies 5. Post-feasibility negotiations 6. Producing mine 7. Acquisition of producing mines or mineral properties. I will conclude with a brief discussion of the mechanics of the financial models that we use at Wright Engineers Limited. As we progress through the seven phases, the availability and accuracy of the data will parallel the complexity and application of the financial models. However, the same basic financial models are utilized throughout the seven phases. I will begin by suggesting that the exploration group is somewhat autonomous and has the mandate to explore in Western Canada.

Jan 1, 1979

16.1.1-VENTILATION'S ROLE Importance of Ventilation and Environmental Control-Mine ventilation is necessary for the preservation of human life and for the conduct of operations involved in the underground extraction of minerals. It clearly is the most essential of the functions attendant to mining, yet it is auxiliary to the primary objective in mineral extraction. Ventilation in mining thus poses a paradox: ideally, it should be carried out with minimum interference with and cost to production operations, yet it is absolutely vital in providing adequate environmental con¬ditions to support mining. Deterioration of the atmosphere, along with rising ground pressure, imposes the ultimate constraint with depth in underground mining. Ventilation requirements and costs rise rapidly with depth. To preserve atmospheric quality under intense heat conditions, ventilation at great depths must be supplemented by air condition¬ing. Likewise, when mining at any depth under severe or excessive conditions of gas, dust or humidity, supplementary control measures must be employed. In recent years, environmental standards in mines have been raised substantially. While limits are based on human tolerance, increasing concern is being expressed for standards of human comfort. The reasons are economic, as well as humanitarian. Worker performance and longevity correlates closely with environmental quality. Further, adverse accident and insurance compensation rates are a consequence of unsatisfactory environmental conditions. No mining company can afford to be lax in its environmental and ventilation practices. Functions and Processes-Ventilation is the control of air movement, its amount and its direction. As a means of quantity control, it is one of the constituent processes of total air conditioning, the simultaneous control within prescribed limits of the quality, quantity and temperature-humidity of the air. Ventilation is the most common and most. important conditioning process employed in mines for air environmental control. In mine ventilation, air is coursed through the mine workings and openings themselves and, for auxiliary purposes, through vent tubing and ducts. Thus, many interdependencies exist between the mining system and ventilation method. In fact, the two often have evolved ,jointly, as in room-and-pillar extraction of bedded or tabular mineral deposits, such as coal. Ventilation in mines today is provided almost exclusively by large fans, although air flow may result due to natural (thermodynamic) conditions. As mines increase in depth, size and complexity, demands on the ventilation system to maintain more stringent standards of environmental quality likewise rise. On the other hand, never have the technology and resources of the mining industry to cope with environmental problems been so well developed as they are today. In spite of rising costs, it is unlikely that further progress in mine ventila¬tion and air conditioning must await technological breakthroughs. 16.1.2-NATURE OF THE MINE ATMOSPHERE Air Mixtures-Air is a gaseous mixture comprising the natural atmosphere at the surface of the earth. Thermodynamically, it may be thought of as a mech-

Jan 1, 1973

By Elmer H. Citron

The Monterey Coal Company, a wholly owned subsidiary of The Carter Oil Company of Houston, Texas, recently awarded a contract to build the Monterey No. 1 Preparation Plant, which will be located near Carlinville, Illinois, to the McNally Pittsburg Manufacturing Corporation. The preparation plant will be one of the most modern jig preparation plants in the State of Illinois. Illinois No. 6 coal will be delivered by a 48" slope belt having 35-degree carrying idlers, operating at 650 FPM and operating on an incline of nearly 17 degrees. The slope belt is driven by two 450 BP motors and will deliver the mined coal at the rate of 1800 TPH to a stationary step-type ' screen having six-inch openings. The overproduct from the stationary screen will discharge into a 10' x 24' McNally Rotary Breaker and the underproduct will bypass the rotary breaker. The rotary breaker is equipped with heavy manganese screens with 6 ½" diameter openings. The sized 6" x 0 coal from the stationary step screen and the rotary breaker will be discharged by gravity to a 4%" raw coal incline storage belt. The 48" raw coal storage belt will deliver the 6" x 0 sized coal at the rate of 1800 T?H to an 8000 ton concrete raw coal silo, 70 feet in diameter and 1x7 feet high. The 6" x 0 sized coal will be drawn from the concrete storage silo by seven (7) 36" wide reciprocating plate feeders. Five feeders are to have constant speed drives at a rated capacity of 145 TPH each. Two (2) feeders will have remote con- trolled variable speed drives, to provide a varying feed.

Jan 1, 1970

By Peter Zhang, Mark Van Dyke, Ted Klemetti, Morgan Sears

Room-and-pillar mining is a mining method used in the United States to extract coal from underground, and pillar recovery is widely practiced for maximizing coal recovery and mining economics. Under certain conditions, room-and-pillar mining can create high stresses in coal pillars resulting in a coal outburst. These outbursts represent one of the more severe safety hazards in underground coal mines, potentially causing injuries and fatalities. Over the past ten years, coal outbursts have resulted in three fatalities in U.S. room-and-pillar mines. Though coal outbursts generally occur under deep cover, they are more likely to occur during pillar recovery and under multiple-seam mining conditions. Coal outbursts are generally associated with strong roof and floor and heavy loading of coal pillars, but it is difficult to predict whether, where, and when they will occur. In this respect, risk management provides a proactive tool to prevent coal outbursts in room-and-pillar mining by identifying mining areas with high risk of outburst and mitigating the risk accordingly.

Apr 26, 2022

By Christian F. Baiz

The author will present a discussion of the steps which must be taken by the prospective developer of a small mining operation to establish technical credibility when seeking financial backing. Particular emphasis will be given to the differing levels of technical work (and their relative cost) which must be accomplished to supply the information necessary to satisfy potential investor groups, whether they be other mining companies, equity investors, or financial institutions such as venture capital firms or commercial banks.

Jan 1, 1981

By Ross W. Smith

Many studies have been made of the microflotation of quartz (1,2,3,4,5,6) and alumina (3,5,6, 7,8) using various anionic and cationic hetero- polar hydrocarbon surfactants as collectors. A few studies have been made on these minerals using amphoteric hydrocarbon collectors ( 9,10, 11,12) and only a few studies have been made on the use of fluorocarbon surfactants as flotation collectors (13,14). The present investigation compares microflotation response of the two minerals in hydocarbon and fluorocarbon collector systems of the anionic, cationic and amphoteric types. An attempt is made to relate flotation response of the minerals to their electrokinetic behavior and the pKa values of the collectors.

Jan 1, 1979

By Mark E. Gershon

Extensive efforts are under way to- ward applying computer techniques to mine production scheduling problems. These efforts are concentrated in four areas: optimization, computerization of traditional methods, heuristics and simulations. These areas complement each other rather than compete. Characteristics of each are discussed toward enabling the engineer to evaluate specific systems that may be encountered. Alternative approaches within each classification are described as well as the motivation for each.

Jan 1, 1985

By J. Creamer

Pumping plays a major role across multiple process and facility applications in the mining world. Examples include: raw water supply, leach solutions, chemicals, dewatering, and mine drainage, and process water for metal recovery. Mining operations such as grinding, classifying, separating and concentrating minerals all have pumps at the heart of the operations Special purpose pumps such as dewatering, process water and slurry pumps are at the heart of many of these processes. Unfortunately the pumps themselves are often overlooked in terms of energy savings potential as they are often embedded into these sophisticated processes which are the ultimate operational focus.

Feb 23, 2014

By D. J. Crawford

The Lucerne Valley Operations of the Minerals, Pigments and Metals Division of Chas. Pfizer & Co., Inca, are located about 5 miles south of the town of Lucerne Valley, California. These operations consist of several limestone quarries, a whiting plant which produces finely pulverized limestone products, a-kiln which produces granular quicklime and lime products, and maintenance shops, warehousing, shipping, and office facilities. Construction of the Lucerne Valley plant began in 1961 as the result of a decision to utilize large undeveloped reserves of limestone in that area. Quarry development was started in the following year; and by 1965, Lucerne Valley had become the principle limestone and lime facility of the Western Operations of the Minerals, Pigments and Metals Division.

Jan 1, 1967

By John G. Holmes

The generation of low cost power is but one phase of the TVA program for regional development. During the 36 years since TVA began, growth in its generation of electric power has necessitated a shift from a predominantly hydroelectric power system to a combination steam and hydroelectric system. The addition of steam-electric power plants to TVA's generating system was necessitated by the rapid increase in the traditional and defense demands for electric power in the 80,000-square-mile area served by TVA, the need to firm up the hydroelectric power, and the fact that all available sites for sizeable hydroelectric projects had been developed. At present TVA owns and operates 40 power plants--29 hydroelectric and 11 steam-electric plants. The total generating capacity of the hydroelectric plants is 3,105,430 kw, and the capacity of the steam plants is 13,951,135 kw. This provides a total generating capacity of 17,056,565 kw for the plants operated by TVA. Individual capacity of the 112 hydroelectric units ranges from 10,000 to 67,500 kw, and the individual capacity of the steam-electric units now in operation ranges from 60,000 to 950,000 kw. In addition to this generating capacity, TVA distributes the power from 6 U. S. Army Corps of Engineers hydroelectric plants on the Cumberland River. These plants contribute an additional 725,000 kw. Also, under an agreement with the Aluminum Company of America, TVA directs the stream flows and generation of their 423,715-kw system on Tennessee River tributaries and shares with Alcoa in the increased generation resulting from this coordinated operation.

Jan 1, 1969

By A. P. Schissler

2013 has seen metals, industrial minerals, and coal all reduce in price due to market and geo-political factors. Many companies are taking write-downs to recalibrate their reserves and have enacted focused cost reduction programs. The public domain includes statements where companies have operating cost reduction goals in the $500 million range. Zero-base staffing & budget analysis is a means to achieve optimal employment and cost levels for a given level of production. The method involves measuring the work to be done similar to Lean. Lean is a method to review each step of production and remove anything that doesn?t add value or is necessary to complete finished goods. Zero-base methodology has been applied to mines worldwide producing realistic and sustainable levels of staffing and costs based on the quantity of work. The objective of this paper is to provide the framework of zero-basing with examples of application.

Feb 23, 2014

By Paul F. Richardson

Liquids containing suspended solids are encountered in most mineral processing applications. Solids levels cover a very wide range, from ppm levels in cooling water systems to slurries containing greater than 70% solids. When the aqueous phase is recycled or further processed, a solid/liquid separation process is used. Chemical additives used to carry out this process are called coagulants and flocculants. In other cases, one seeks to control or modify the properties of the suspension. Dispersants are chemicals used to aid in suspending solids in a liquid as well as to control the properties of the resulting suspension. Dispersants find a range of uses in mining and mineral processing such as scale control, filter aids, flotation aids, and slurry viscosity modification. Materials used as dispersants include inorganic salts, alkalies, organic surfactants, and polyelectrolytes. This paper discusses the use of dispersants in mineral processing, with an emphasis on control of slurry viscosity. The mechanism of dispersion and factors that affect the choice of dispersant will be discussed.

Jan 1, 1986

By H. Kellerwessel

This paper refers to the new crushing and grinding process, which was invented by Professor Schönert (Ref.1), Clausthal, Germy (author of one of the papers presented at this meeting). The process is known as high pressure particle bed comminution or interparticle crushing. Several papers by Professor Schonert and his coworkers and by specialists of the companies producing the necessary equipment under license agreements already described fundamentals of the process, the equipment used, results of lab size and large scale tests and finally the first results of truly commercial operations (Ref .2 to 11). Therefore it should be sufficient to summarize the main facts here: - To a bed of bulk material a pressure of more than 50 MPa is applied. Comminution is achieved mainly by the pressure which one particle transfers to the other and not by squeezing single particles between the working surfaces of some crusher or grinding media.

Jan 1, 1987

By Ray W. Ballmer

Historically, Bingham is a rail pit, starting with steam locomotives in 1906 and converting to electric locomotives in 1923. Ore production was maintained through an effective utilization of available rail equipment. From time to time as it became necessary to deepen the pit and as stripping ratios increased, various studies were made on alternate material haulage systems. Utilization of diesel locomotives, conveyor belts, and trucks have all been subjects of study, however, conversion from rail haulage utilizing electric locomotives could not be justified. Because of the gradual decline in ore grade, a program was approved in 1963 to raise ore production to 108,000 tons per day. This was designed to return copper production to the 1950 level. Attainment of this production level by expansion of the rail system had definite limitations and built-in inflexibility. Track and trolley wire relocation causes shovel down time in excess of that required for normal maintenance. Instability of the dumps and the resulting additional track maintenance increases greatly as the volume of waste material to be handled daily expands.

Jan 1, 1965

By Niles E. Grosvenor

One of the most important considerations in the efficient operation of an under¬ground mine is the haulage system. Often the determining factor between profit or loss is the quick removal of ore and waste from the working places to secondary and main-line haulage areas, and so on to the outside. Important, too, is moving supplies from the surface to the working faces so that the loading process can continue with little interruption. Men must he transported in a rapid but safe manner. It has been through the efficient use and generally the combination of mine cars, track, belt conveyors and rubber-tired haulage equipment that underground operations have been able to compete with the more popular strip or surface mining. As near-surface ore bodies are exhausted, underground haulage will play an expanding part in economically furnishing the world's needs for all types of minerals. The choice of underground haulage equipment, wherever possible, should be one that will give the smallest overall cost of ore removal during the life of the mine while meeting necessary safety requirements. The reader is referred to Sec. 12 for equipment such as scrapers and load-dump-¬haul units that perform loading as well as haulage duties. 14.1-MINE CARS AND TRACK NILES E. GROSVENOR Main-Line and Secondary Haulage-Many mines today use a combination of belt and rail haulage. Even if a- belt system is used to carry the product from the face to the surface, track is used to transport workmen and supplies. A track system, when properly installed, will provide interruption-free and safe haulage. Schrecengost 2 lists the following as major advantages of track haulage: 1. Safety in transporting men in and out of the mine in personnel cars. 2. Easy and rapid transportation of supervisory personnel. 3. A temporary shutdown occasioned by a roof fall or power failure along the haulage system will not shut down the production areas. 4. Quick availability of repair parts and supplies. 5. Large pieces of coal or rock can be handled without damage to the haulage equipment. 6. In areas where quality fluctuates noticeably, different cars may be separated out for special preparation. 7. Rock or equipment may be loaded and moved out of the mine without interference with the production or preparation of the coal. 14.1.1-MINE CARS Mine cars with steel bodies are used in all types of present-day mining. Wooden cars usually are more bulky and less resistant to wear and damage, but are more easily repaired. Regardless of the type of mine car selected, it is most practical to standardize on one type or make to simplify repairs and limit the amount of spare parts necessary to stock. Rigid-body flat-bottomed cars are simpler and usually lower than others of equal capacity. Advantages are: ease of loading because of the low sides, simplicity, cheapness and high ratio of capacity to weight. The disadvantages include the

Jan 1, 1973

By Steve Karl, Rock Jenkins

The mining industry appears to be slowly rebounding. But many individuals and company officials are still smarting from the beating they received during the recent recession. As a result, companies have taken the "lean and mean" approach. As pointed out at the Oct. 24-26, 1984 SME-AIME Fall Meeting in Denver, CO, companies are placing more emphasis on optimizing their operations through more efficient mining and processing technologies and equipment. Empathizing with the mining industry's woes was the meeting's welcoming luncheon speaker, John D. Withrow, Jr., executive vice president product development for Chrysler Corp. Withrow paralleled Chrysler's problems of a few years ago with the current problems facing the US mining industry. He said Chrysler's come-back centered around its engineering and technical personnel, who regained "their seat at the head table." "In short," Withrow said, "we had lost the competitive edge. By cutting costs and people and improving our products we got everybody to believe we could." The 2700 participants at the Fall Meeting attended technical sessions geared toward turning mining back into a productive and profitable industry. Sessions and symposia included papers on precious metals extraction, crushing and grinding innovations, geomechanics, environmental control, health and safety, and various commodities. This article briefly highlights some of the papers presented. To order preprints of these technical papers, see ME, December 1984, pages 1620 and 1621. Computers Gain Mining Acceptance High tech has reached mining. As evidenced by many papers, computers have become valuable tools in many applications. These include tailings ponds operation and waste management; truck dispatching; mine design, simulation, and scheduling; monitoring; and reclamation. Mine planning is generally labor intensive and requires a considerable amount of the planner's time. P. K. Chatterjee, X. Chung, and Y. Jianjy described a computer-generated interactive graphics approach to under-ground coal mine planning that lessens the manhours involved in producing plans. The computer program examined exploratory borehole information. This included coal seam thickness, tonnage, quality constraints, and the nature of their distribution. Layout designs were then initiated and a probabilistic simulation performed to determine production levels of different extraction strategies. The interactive graphics approach gives planners the ability to quickly evaluate several layout alternatives and select the best one. For surface coal mines, M. A. White, of Arch Minerals Corp., explained several computer programs that aided in his company's surface mine plans. Several drill hole database and modeling pack¬ages are available. But Arch tech¬nicians developed specific pro¬grams for model strip areas. They were used to form long-term pro¬jections for various area and semi¬area stripping operations. They also generated reports on yard¬age, tonnage, quality, and ratio in¬formation. The information is used in budgeting, to compare mine plans, and to analyze acqui¬sition candidates. While computer-based truck dispatching systems have been used in mining for some time, earlier systems were run on ex¬pensive mainframe or high per¬formance minicomputers. As such, computer-based truck dis¬patching systems have been too expensive for all but the largest mines. Recently, however, a microcomputer-based system, af¬fordable to smaller mine opera¬tors, has become technologically feasible. Y. C. Kim and W. E. Kolb re¬ported on a simulated microcom¬puter system that uses strategi¬cally placed signposts in the pit area to automatically detect truck movements. A microprocessor in the signpost sends information to the microcomputer. The computer determines the truck's assign¬ment and alerts the dispatcher. He radios the driver his assign¬ment. In addition to the technical pa¬pers, an introductory short course on microcomputers was offered at the meeting. L. M. Kass and J. P. Stone, from the US Bureau of Mines, walked participants through the uses of microcom-

Jan 1, 1985