Search Documents

By Joseph J. Garbarino

World demand for phosphate fertilizers has grown at an average annual rate of between 6 and 7 per cent over the past 10 years. In the next five years world demand is expected to at least continue to grow at that rate. Also, the continued need for improved fertilizer materials, coupled with improvements in fertilizer technology, have placed added importance on the use of phosphoric acid as a starting material for high analysis phosphate fertilizers. This demand for phosphates and phosphoric acid must be met by increased production. Increased phosphoric acid production also brings increased demand for chemical processing agents including foam control agents. We at Arizona Chemical Company have closely followed the phosphate fertilizer industries needs. Arizona Chemical Company has been an important supplier of flotation agents to the phosphate industry, primarily from its Panama City, Florida plant. We have also recognized the important role played by foam control agents in the wet-phosphoric acid manufacturing process. We feel it is the responsibility of the supplier of foam control agents to offer specifically designed products that are highly efficient and economically useful. The difficulties involved in evaluating foam control agents in the plant are recognized. Owing to the large number of variables present, and the difficulties in controlling these variables during the period of a plant trial, plant evaluation of a large number of foam control agents is impractical. We have attempted to develop a practical, reproducible, and yet rapid, laboratory evaluation test which correlates with plant performance.

Jan 1, 1966

By G. Buchan

This paper discusses the design of long panels for longwall mining at Twentymile Coal Company (TCC) from conception to implementation. The case study of the long panels at Twentymile includes extensive mine plan reengineering in the early 1990's to world record production months in 1996 and 1997. The obstacles of subsidence engineering, environmental regulations, conveyance, ventilation, equipment design, and continuous miner (CM) development timing had to be overcome to successfully begin longwall production within a 4 year time frame. The background and some detail for each of these areas listed will be discussed to show how the coordination of many facets must be pulled together to implement a successful long panel mine plan.

Jan 1, 1998

By Wedam Nyaaba, Edward Wellman, Angelina Anani, Eduardo Cordova, Sefiu O, Cluber Rojas, Adewuyi

This study aims to investigate the optimal method for ore pass construction in incompetent rock masses. We evaluated the conventional and raise boring methods based on safety, efficiency, excavation control and ground support for ore pass construction. A stability analysis using analytical Q-raise (QR method) and kinematic analysis methods for ore pass construction with a raise borer before and after grout injection of the rock mass was performed. As a case study, an ore pass (diameter of 3 m, depth of 100 m) within an incompetent rock mass was considered to gain further insight. The rock mass was characterized according to the classification methods Q Barton, rock quality designation (RQD), rock mass rating (RMR) and geological strength index (GSI). The grout intensity number (GIN) method of grout injection was used. The safety factor of less than 1.075 obtained before injection was lower than the acceptance criteria. However, grout injection before raise borer excavation resulted in a safety factor greater than 1.5. Using a raise borer without pre-grouting indicated that the maximum unsupported diameter (MUSD) of the ore pass was less than the required 3 m and equal to or larger than 3 m post-grouting.

Dec 1, 2024

By Barbara H. Carroll

In order to rapidly evaluate an area for its mineral potential, a reconnaissance exploration program generally includes the following: 1. Outlining an area of interest 2. Identifying known mineral deposits 3. Bibliographic search of the literature 4. Evaluation of geochemical and geophysical surveys 5. Compilation and review of geologic maps The information now available from various government agencies regarding the mineral deposits, geology, and geochemistry may be integrated and used as a tool to rapidly evaluate an area before the field season. The databases most commonly used in the United States are the USBM MAS/HILS system and the USGS MRDS system for their information on mineral deposits; GEOREF and GEOARCHIVE for bibliographic information; and NURE data for the geochemistry and geophysics. In conjunction with the project geologist, this information may be used to plot known deposits and their geochemical signature as well as any other areas of like signature for further examination.

Jan 1, 1985

By J. W. Gunnett

Abstract. The Surface Mining Control and Reclamation Act of 1977 (PL-95-87), Section 522, establishes requirements for state regulatory authorities to designate lands unsuitable for all or certain types of surface coal mining. Any party having an interest in an area that may be affected can petition for it to be designated unsuitable for mining. Section 522 could present major obstacles to the mining industry by typing up an area in an endless round of petitions. The program under development for Kentucky is examined and analyzed as an example for determining the hidden impacts of Section 522.

Jan 1, 1980

By Richard D. Zigmond

In this paper, a computer program that has been developed for determining the capital and operating costs for coal preparation plants is described along with its applications. The logic of the computer program is based upon the results of a survey of existing preparation plants, operators, plant contractors, equipment manufacturers, and consulting firms. This survey provided information on plant performance, order-of-magnitude costs, and costing procedures. Additionally, an extensive cost data file for the major capital equipment in coal preparation plants has been developed. Using the washability data and the computer program outputs, the cleaning costs per million Btu can be calculated. Details about the program and its applications can be found in a report by the authors (Zigmond et al., 1979).

Jan 1, 1981

By Y. J. Wang

This paper describes a graphical technique by which the operating points for a two-fan ventilation system can be represented as the intersection of the modified fan curves. In constructing the diagram, the air quantities associated with the fans are considered to be independent variables and employed as the axes of a rectangular coordinate system. The diagram may include, in addition to the modified fan curves, contour lines for resistances, pressures, and air powers. Procedures for drawing the diagram are discussed and illustrated with an example of the ventilation system.

Jan 1, 1985

This paper presents a method for evaluating the economic feasibility of solution mining a hypothetical uranium roll-front deposit. It is assumed the wellfield will be operated in a prudent manner and that leaching tests were performed in depth in both lab and field (push-pull) prior to startup. Leach test results are reduced to two important parameters and used as the basis for solution mining a wellfield. This case study assumes a 10 mil- lion-lb uranium deposit with 40 possible small wellfields; four are kept in operation simultaneously until the deposit is depleted. The wellfields have different ore reserves and grades, lixiviant circulation rates, leach rates, and peak concentrations, and thus the daily uranium production will vary. Daily production is used to assess the profitability of a particular lixiviant and the mode of well- field operation in light of realistic market price estimates. The mathematical procedure is simple and straightforward, based on reasonable in-situ leaching relationships as well as accepted accounting practices.

Jan 1, 1985

By D. E. Ranta, William B. Ryan, Ronald W. May

The Lower Cretaceous McMurray Formation in northern Alberta contains bituminous sands interbedded with other sediments which form the reject encountered during mining operations. Grade prediction is based on a combination of geological interpretation, computer modelling and past mining experience. In addition to estimates for ore, an accurate estimate of "waste" or "reject," are required for Mine Planning. This study investigates the ability of point-kriging using geostatistics, to augment the existing data base of drill-holes in a study area on Syncrude's leases. This approach enables the assessment of potential "worst" case - "best" case scenarios within the context of Mine Planning.

Jan 1, 1992

By T. J. McKeon

Gravity separators such as spirals are commonly used in multistage cleaning and scavenging circuits to improve the quality and recovery of concentrates produced in the industrial minerals industry. Unfortunately, field surveys suggest that many industrial operations are poorly configured in terms of equipment layout. This shortcoming can often be attributed to a failure by engineers to make use of fundamental process engineering tools for circuit design. One of the most important of these is linear circuit analysis. This powerful tool makes it possible to mathematically compare the relative efficiency of circuit configurations in advance of experimental testing. This article provides a basic review of the linear circuit analysis concept and discusses some of the key insights it provides for the layout of multistage circuits. An industrial case study is provided to show the tremendous impact that this process engineering tool can have on the design of multistage spiral circuits in a heavy mineral wet plant.

Feb 1, 2012

By Muriel S. Robinette

Ground-water contamination from uranium operations could be avoided with proper site analysis techniques. Contamination from tailings disposal sites is carried downgradient within permeable hydrostratigraphic units which can be located and delineated with a combination of drill holes, borehole geophysical logs and surface geophysics. Several case studies are presented to illustrate this application.

Jan 1, 1980

By J. McCreedy

The Ontario Division of The International Nickel Company of Canada, Limited, operates five underground mines and one open pit on the rim of the Sudbury Basin located in the Province of Ontario, 230 miles northwest of Toronto. Four of the mines, Frood-Stobie, Creighton, Murray and Garson, lie on the South range of the Basin within a 10-mile radius of the City of Sudbury; the fifth mine, Levack, is on the North range, about 30 miles northwest of the city. The ores are mined primarily for nickel and copper, the principal minerals being pentlandite and chalcopyrite. Other elements recovered from the ores in varying quantities are platinum, palladium, ruthenium, iridium, rhodium, cobalt, selenium, tellurium, iron, sulphur, gold and silver. In 1962, the total underground ore production was over 10,800,000 tons which was mined mainly by blasthole and caving methods with the remainder by cut-and-fill, square set, and undercut-and-fill techniques.

Jan 1, 1964

By Ralph M. Barnett

It is no longer a question of "If" mining operations will meet standards and regulations set by various governing bodies and the demands of citizen groups. Legislation is fact. The needs of citizens are becoming more of a integral part of mining company planning. "Open Planning", regardless of some frustrations it provides, is working. Climax, AMAX Chemical and AMAX Exploration are successfully employing several citizen involvement techniques in exploration and feasibility study phases of planning for potential new mines.

Jan 1, 1978

By E. J. Sullivan

This study seeks to define the mechanism of oxyanion sorption onto surfactant-modified zeolites. Zeolites which have been treated with hexadecyltrimethylammonium bromide (HDTMA) surfactant to produce a hydrophobic surface are capable of sorbing both organic compounds as well as oxyanions such as chromate, selenate, and sulfate. Simple ion exchange and charge-balancing mechanisms do not fully explain this unusual phenomenon. The sorption of HDTMA surfactant appears to be partly ion exchange and partly sorption to non-ion-exchangeable sites. Sorption of chromate is a simple exchange mechanism with bromide, which co-adsorbs with HDTMA to form a surface precipitate. Information from this study will be used to design on-site and in situ treatment systems for contaminated water, such as filter beds and permeable barriers.

Jan 1, 1995

By Adrian E. Scheidegger

Recently, a new theory of the subsidence of rock masses has been advanced by Litwiniszyn and coworkers, which is based on the notion that the individual rock particles perform random walks. It is shown in the present paper that the final equations of the random walk theory can be justified from general principles of statistical mechanics in which no specific theoretical model of particle behavior has to be made. The theory appears to account appropriately for subsidence phenomena.

Jan 1, 1966

By J. M. Pugliese

The U.S. Bureau of Mines is developing designs and estimating costs for vertical in situ copper mining wells as part of its in situ mining research program. Conceptual designs and estimated costs for "deep" 1100 m (3600 ft) recovery and injection wells in an undisturbed copper ore zone are presented. Within a single in situ copper mining well, multiple perforated well completions and associated costs are discussed for two ore zones between depths of 370 m (1200 ft) and 550 m (1800 ft). The order of well specifications for designing these wells is explained.

Jan 1, 1995

By Mark E. Gershon

The development of long term plans and schedules for strip mines now faces many companies, especially those developing large properties in the West. The rule of mining the lowest strip ratios first, while delaying equipment acquisitions and recouping investment the fastest, creates the situation where stripping ratios are too high in the latter years of mining operations. A program concept taking life of mine return on investment into account is developed in this paper to optimize mine scheduling and equipment acquisition. In addition, quality considerations (heat content, ash, sulfur, washability) can be considered by including the appropriate blending constraints to meet contract requirements.

Jan 1, 1983

By Gilman Y. Murray

The problems connected with the development of economically acceptable water supplies in arid regions are discussed. The techniques for capture and retention of runoff from infrequent desert storms are described and the major factors involved are emphasized. The exploration and planning for a typical water development in southwest United States is described, including an analysis of capital and operating costs for the proposed system.

Jan 1, 1963

By S. D. Thompson, L. Adler

Several researchers in the last 20 years have developed computer simulation models for designing coal mine belt systems. A careful review of these reveals that each omitted or oversimplified important factors, especially in belt loading. To remedy this, the coal mine belt capacity simulator (CMBCS) was developed to include various types of probability distributions, delays, and longwall and continuous haulage. CMBCS is computer coded in FORTRAN and employs the Monte Carlo simulation technique. Basically, the model simulates the loading and corresponding flow of coal through a belt system. By recording spillage and belt stoppage statistics for the simulated flow, belt and surge bin capacities can be evaluated. A complete user's guide is available. The modeling and verification of CMBCS are briefly described, and its major advantages and disadvantages are explored.

Jan 1, 1987

By Silas Li, Michael Harris-Gifford, Jason Choi, William H. Hansmire

Twin-bore tunnels with a single track in each tunnel are currently the most common subway tunnel configuration. However, a large diameter single-bore tunnel with two tracks separated by a center wall could replace twin-bore tunnels and introduce potential benefits but require necessary modifications to the subway system. In particular, a nominal 40-foot-diameter single-bore tunnel can be considered in lieu of nominal 20-foot-diameter twin-bore tunnels. This paper discusses the benefits and modifications introduced by replacing twin-bore tunnels with a single-bore tunnel, with respect to various elements of the subway related to the tunnel, stations, track, and tunnel systems.

Dec 1, 2022