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By T. Ogasawara, J. P. Barbosa, A. J. Monhemius, F. T. Da Silvia

A thermodynamic analysis of the sulphation of rare-earth phosphates and the water-leaching of rare-earth sulphates was used to guide experimental work on the sulphation and leaching of concentrates from Pitinga. It was concluded that the sulphuric acid digestion of xenotime is technically feasible and could be used industrially to produce yttrium and other rare-earth oxides. Yttrium extractions of more than 90% were obtained by digestion at 503 K for 4 h at an acid:concentrate ratio of 2:1 with particle size -0.053 mm. The apparent activation energy at temperatures less than 473 K, as determined from the Arrhenius plot, was 11.0 kJ/mol, indicating that the reaction is controlled by the diffusion of the reactants or products through the sulphate layer

Jun 19, 1905

By N. Chow

The recovery of manganese from lower grade resources has been studied for a number of years. Of key importance of prior work, was the discovery that higher valent manganese resource can be readily leached with sulfurous acid. This eliminates the need for high temperature reduction roasting that is conventionally used in processing high grade material. High temperature roasting is energy intensive, emits a large amount of carbon dioxide, and would not be economical for processing lower grade material. While the prior work provides important information to extract manganese from lower grade resources, the production of unwanted by-products, and high water and energy usage has limited its commercial use. This paper describes the results from laboratory work that demonstrate solutions to problems, which to this point preclude commercial development. Preliminary mass and energy balances show that a significant opportunity exists in producing manganese with this hydrometallurgical scheme in a low cost, environmentally friendly manner. Emphasis of the work is on low water use, low overall energy use and economic destruction of unwanted by-products.

Jan 1, 2011

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

By John L. White

Vibratory driver/extractors do more than drive and extract sheet piles. I would say more than sixty percent (60%) of the time, vibratory pile driver/extractors are engaged in work that has nothing to do with sheet piles. This is the main reason I refer to this tool as a "driver/extractor", and omit the word "pile". I have spent the last twenty years applying the technology of the vibratory driver/ extractor to all areas of foundation construction. As you will see, the only limits are humankind's ingenuity.

Jan 1, 1997

Cyclone Process for Heavy Metals Decontamination of Sediments

Sep 13, 2010

By Kenneth H. Johnston

This publication describes a thermal-recovery project and two waterflood projects in Carter, Garvin, and Stephens Counties, Okla., that will be visited during the 1966 annual tour by the Bureau of Mines in cooperation with the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects arc (1) the movement of heavy (15° to 28° API gravity) crude oil through the reservoir and into the well bore with energy furnished by burning a portion of the crude oil therein; (2) the use of an inverted nine-spot pattern with dually completed injection wells, to produce oil from deep (8,200 to 10,200 feet) reservoirs; and (3) the flooding of five sand lenses separately by using controlled water injections through multizone completed injection wells. Discussion of the individual projects includes information on their early history, method of completing and operating wells, source and treatment of injection fluids, oil production decline curves, and the results obtained from the development.

Jan 1, 1966

By Mohamed Yusuff

Modern transportation systems are one of the most important achievements of our civilization and provide us with tools for broadening individual and social freedom of choice. The transportation system initiated today is handed dawn to the next generation, probably with little choice because of the enormous expenditure of monies involved, and influence their way of life as to where they should live and where they should work. The ever increasing antagonism between the citizens and the planners of the transportation systems necessitates a careful review of the entire planning process. The planning process can be broadly classified into: the goal formulation and decision making process; the plan development process; and the plan implementation process. THE GOAL FORMULATION AND DECISION MAKING PROCESS Goal formulation and decision making is one of the vital phases of the planning process and is primarily based upon social values. In measuring social values, the planner must employ an appropriate scale of measurement since in the absence of this yardstick, these values tend to became vague and abstract ideals. The need for major social programs and concerns (poverty, etc.) of the urban areas should be analyzed to determine the type of transportation system which would contribute to the solution.

Jan 1, 1974

By Frank E. Cash

The work of the United States Bureau of, Mines is concerned primarily with the prevention of accidents in the mining, petroleum, and allied industries. This report analyzes the fatal accidents in the coal mines of Tennessee and gives the pertinent factors in tabular and descriptive form, with interpretations and suggestions to operators, workers, and the State Division of Mines for the future prevention or reduction of accidents in coal mines. ACKNOWLEDGMENTS This study was made possible through the cooperation of A. W. Evans, chief mine inspector of Tennessee, and his secretary, Miss Hiliary Penny, who made available the department records and assisted in the segregation and assembly of the data.

Jan 1, 1935

By Dennis J. Callaghan

This report is the result of information obtained from a review of related literature, personal inquiry and on-site examination of active surface coal mining operations. Four improved surface coal mine systems are described in detail and evaluated for feasibility, implementation requirements, environmental benefit and costs. Engineering feasibility emphasizes equipment availability, compliance to design requirements, practicality and industry rating. Implementation potential emphasizes immediacy, ease, acceptability and constraints. Special attention was given to environmental responsiveness, both with regard to the solutions to mined-land reclamation problems and to the concurrency of reclamation. Each system description includes a hypothetical model mine with a depreciation schedule, capital summary, estimated annual production costs, sales price computation, production and operating cost summary, and a sensitivity analysis of mine price to stripping ratio. A program plan and time schedule for demonstrating a selected mining system covers site selection criteria, mine data collection, criteria for controlling and budgeting costs and reporting findings. Ten additional mining methods and techniques are briefly described and evaluated. Common reclamation problems are listed and described. Sixteen state reclamation laws and regulations are abstracted. Sixty-nine references are listed in the bibliography.

Jan 1, 1976

Gravity-driven rock falls account for a large proportion of all fatalities and injuries in underground mines. Potentially unstable blocks of rock are found in the hanging wall of excavations, which may be delineated by natural joints or stress fractures. These blocks, referred to as keyblocks, will fail if their weight exceeds the support capacity or if they are located between support units. This paper describes a computer program which simulates blocks in the hanging wall of an excavation based on measured properties of fractures and joints. Keyblocks are identified and placed at random locations in a predefined excavation. The keyblocks are tested against the support to determine whether they fail the support, drop out between the support or are stable. By repeating the procedure several thousand times, statistics of the probability of failure of the keyblocks are obtained. This approach allows the relative hazard associated with different types of support or excavation orientations to be obtained. It is concluded that a probabilistic approach is suitable for the evaluation of supports effectiveness in situations where large numbers of discontinuities or stress fractures are exposed in excavations.

Jan 1, 1998

By H. K. Lin

The effect of metallic iron fines on froth flotation of a sulfide ore was examined by comparing the flotation results with and without iron fines present in the flotation feed. Mild steel and ceramic laboratory ball mills were used to grind 600 g sulfide ore charges. The mild steel ball mill generated approximately 4.6 g of iron fines (0.8% of the ore charge mass) when grinding to a product size of 80% passing 200 mesh (75 mm). When a low dosage of a weak xanthate collector was used in flotation, the impact of the iron fines on sulfide flotation was marked. Higher dosages of stronger xanthate collectors rendered the impact of the iron fines much less significant. Consumption of the collectors by the powdery iron fines is believed to cause the differences observed in the flotation results. A galvanic effect on flotation was not evident in this study. The impact of the iron fines on silicates depression was also examined.

Jan 1, 2008

By Rodney K. Morrison

MARTA, The Metropolitan Atlanta Rapid Transit Authority, is building a 53 mile heavy rail transit system to serve the City of Atlanta. Phase A of the Rail System, consisting of approximately 14 miles of at-grade, aerial and subway construction is underway. Metropolitan Atlanta lies in the Piedmont Geologic province of Georgia and is underlain by rocks of essentially granitic and gneissic nature. The soils encountered are primarily silty sands which are in-place weathering products of the parent rock and exhibit their relic structure. In general, these materials have presented no unique construction problems other than those created-by proximity of manmade structures, local availability of ground water, and top of rock elevation. The subway sections of primary interest in this paper consist of hardrock and soft ground tunnels and extensive cut-and-cover sections. The cut-and-cover construction includes excavations as deep as 80 feet. Temporary support systems in these deep excavations consist of soldier pile-timber-lagging or soldier pile-tremie concrete (SPTC) walls with internal bracing or tiebacks. In shallow cut-and-cover sections, where right-of-way economics permitted, slopes were laid back partially or fully to reduce or eliminate the need for bracing systems. Dewatering systems were required in most open cut excavations. Due to the close proximity of utilities and existing structures to the MARTA

Jan 1, 1979

By Robert L. Lappi

Eight interburden handling concepts are developed for multiple seam area mine stripping operations in central and western United States. They are based on data gathered and analyzed during field surveys, literature reviews and visits to state requlatory agencies in five states. It is concluded that improvement of reclamation practices through selective interburden handling techniques is possible at lower operating costs than currently incurred. Specific multiple seam mining systems are discussed in this report.

Jan 1, 1980

By Spencer S. Shannon

This chapter is concerned with the uses, geology, exploration, evaluation, preparation for markets, and future of 90thorium and 39yttrium, along with 14 rare-earth elements. The rare-earth metals or lanthanides were divided into three categories by Berzelius. The cerium subgroup is comprised of 57lanthanum, 58cerium, 59praseodymium, 60neodymium, and 62samarium. 61Promethium does not occur naturally. The terbium subgroup includes 63europium, 64gadolinium, and 65terbium. The remaining lanthanides are placed in the yttrium subgroup. Strictly speaking, yttrium is not a rare earth. Because the properties of yttrium resemble those of heavy rare earths, its name has been used as a designating adjective. The yttrium subgroup includes 66dysprosium, 67holmium, 68erbium, 69thulium, 70ytterbium, and 67lutetium. Rare-earth elements, especially those of the same subgroup, tend to occur together rather than in discrete minerals.

Jan 1, 1975

By Lewis M. McNay

The strength characteristics of hydraulic sandfill modified by varying quantities of type III portland cement and two flocculants were investigated by the Bureau of Mines. Three different sand-cement ratios were examined using different percentages of flocculant. Two other experimental variables were curing time and weight-percent solids for hydraulic mixture. Results of unconfined compression tests with strain are discussed. Maximum strength was achieved with 0.5 weight-percent of ferric sulfate per ton of solids when the slurry mixture was 75 weight-percent solids. The bearing capacity of hydraulic sandfill is reduced by increasing the water content and decreasing the amount of cement mixed with sandfill.

Jan 1, 1976

By Bali. D. D., S. Chattopadhyay

"The planning and construction of prime coking coal beneficiation plants in the nationalized mines in India are reviewed. Flow schemes, construction practice, materials consumption, and costs are detailed.Medium-capacity beneficiation plants with multiple loops are recommended under Indian conditions.IntroductionThe reserve of high-grade and easily washed metallurgical coal in India are quite limited. Prime coking coal constitutes approximately 22% of the total resources and occurs exclusively in the Jharia coalfield in the state of Bihar. Bharat Coking Coal Limited (a subsidiary of Coal India Limited (CIL) the nationalized mining sector of India) owns 80% of the Jharia collieries. The development of Jharia coalfield in the pre-nationalized period before 1971 has been characterized by a large number of small mines with primitive mining methods and low productivity. The production of prime coking coal to meet the demand of the steel industry in India has to increase from the existing level of 11.1 million tonnes to 43.4 million tonnes per annum by 2000 AD, thereby producing 5.61 million tonnes and 22.7 million tonnes of clean coal respectively. An ambitious program has been undertaken for development of bigger mines with an average production of 1 to 3 million tonnes per annum. With the fast dwindling reserves of good quality coking coal, more inferior grade coal seams, having difficult washing characteristics, are now being mined. All the coal from the future mines will have to be beneficiated to make it suitable for consumption of steel plants; the following washeries are being planned for construction by 2000 AD:"

Jan 1, 1986

By John Trefny

Although mining is currently one of the smallest academic units on the Colorado School of Mines(CSM) campus, it is alive and well, with nearly 100 undergraduate and graduate students. For many years, Mines has had undergraduate and graduate programs in hard-rock mining. The school has recently transferred its physical mineral processing activities to the Mining Department. The program has also expanded to include tunneling, underground construction and industrial minerals. There are current discussions about increased research activities on cement and other construction materials. The Mining Department also teaches its share of what is called the “distributed core” courses with curricular requirements common to related programs, as well as mining safety and health, in conjunction with our continuing education department.

Jan 1, 2002

By HENRY M. PARKS

THE total production of all metals in Oregon to date is estimated at $160,000,000; ~115,000,000 from eastern Oregon and $45,000,000 from the western part of the state. In 1916 the metal production of the state was approximately $4,000,000, while the present annual production has dwindled to a little less than $1,000,000. Western Oregon The state of Oregon contains several metal-bearing areas, widely scattered in different regions. More than half of its coast is fringed with a belt of auriferous sands which sometimes are rich in fine gold. A second mining field, the chief producing one of western Oregon, is situated in the southwestern part of the, state and includes Jackson, Josephine, Douglas, Coos and Curry counties. It may be considered as the northern extension of the gold and copper belt of California. A third region in western Oregon is that on the western slope of the great Cascade range in the Bohemia, Blue River, Quartzville, North Santiam and Ogle Creek districts-from the Siskiyous on the south almost to the base of Mt. Hood near the Columbia River on the north.

Jan 1, 1925

By J. -G. Swanson

Dust control in longwall coal mining depends primarily on the prevention of dust at the source and secondarily on the suppression of airborne dust. One of the primary methods for the prevention of dust is the wetting of the coal face prior to extraction, which can be achieved with water spray systems installed on the shield supports. The spray droplets must travel across the airway to the longwall face, where high ventilation air speeds can entrain water droplets and prevent them from reaching the face thus minimizing the dust control at the source. Through an evaluation of spray plume characteristics in a wind tunnel, the droplet size and droplet drift behavior was determined. This drift behavior was examined by evaluating the spray plume concentration drop and the droplet size shift near the nozzle exit at varying air speeds. Based on these evaluations, CFD modeling was applied to simulate the spray behavior for varying geometries. These results led to the selection of appropriate spray nozzles capable of carrying water droplets to the face at higher air speeds, resulting in an adequate wetting of the coal face and reduced dust generation.

Jan 1, 2012

By S. Banisi, M Nesari, J. A. Finch, N. Nobari, H. Javani

"The flotation circuit of the Sarcheshmeh copper mine, which processes 40,000 t/d of ore at 0.9% Cu, consists of rougher, cleaning and recleaning stages. Mechanical flotation cells are used in all stages. To investigate the amenability of flotation columns in the plant especially for cleaning and recleaning stages, a column was designed, constructed, and installed at the Sarcheshmeh pilot plant. The pilot plant, which has an identical circuit configuration compared to the plant, can process up to 2 t/h of ore. The overall rate constant of the ore along with the target recovery of 94% were used to size the column. A 26 cm by 550 cm column with two filter cloth spargers and a submerged froth washing system using perforated tubes was constructed. To detect the interface level a 180 cm conductivity probe consisting of 1.5 cm diameter ring electrodes was installed. The tailings flowrate controlled by a variable speed pump was used as the main control variable. The initial testing program revealed that the optimum superficial gas and wash water flowrate were 1.5 and 0.3 cds, respectively. It was observed that the cleaning stage grade when using the column could increase by 2-3% at constant overall copper recovery.IntroductionThe Sarcheshmeh copper ore body which may rank as third or fourth largest in the world contains 1 billion tomes averaging 0.90 % copper and 0.03 % molybdenum. It is in located south-east Iran and has been processing 40,000 t/d of ore since 1982. After three stages of crushing, the ore with a F80 of 12.7 mm is fed to 8 parallel ball mills in closed circuit with cyclones to produce a product 70% finer than 75 microns. The concentrate of the first stage of flotation is reground and the tailings constitutes the main component of the plant final tailings. A concentrate with an average grade of 31% Cu (chalcopyrite and chalcocite) is obtained after cleaning and re-cleaning stages in mechanical cells. Total recovery of the plant varies between 83-87 % depending on ore type and operating conditions."

Jan 1, 2000