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By D. E. Karvelas

Argonne National Laboratory is conducting research to develop a cost-effective and environmentally acceptable process for the separation of high-value plastics from discarded household appliances. The process under development has separated individual high purity (greater than 99.5%) acrylonitrile-butadiene-styrene (ABS) and high-impact polystyrene (HIPS) from corruningled plastics generated by appliance-shredding and metal-recovery operations. The process consists of size-reduction steps for the commingled plastics, followed by a series of gravity- separation techniques to separate plastic materials of different densities. Individual plastics of similar densities, such as ABS and HIPS, are further separated by using a chemical solution. By controlling the surface tension, the density, and the temperature of the chemical solution, we are able to selectively float/separate plastics that have different surface energies. This separation technique has proven to be highly effective in recovering high-purity plastics materials from discarded household appliances. A conceptual design of a continuous process to recover high-value plastics from discarded appliances is also discussed. In addition to plastics separation research, Argonne National Laboratory is conducting research to develop cost-effective techniques for improving the mechanical properties of plastics recovered from appliances.

Jan 1, 1996

By Chen-Luh Lin, Jan D. Miller, Sindhoora Puvvada

The depletion of good-quality phosphate resources, coupled by a need to supply acceptable products at a rapid rate, while meeting the specifications of fertilizer chemical plants, is of significant concern to the phosphate industry, particularly the production of concentrates with tolerable dolomite content. Tremendous efforts have been made in the past to develop an efficient and economical process that can effectively reject dolomite. However, dolomite removal continues to plague the phosphate industry due to several process-specific challenges being encountered with various beneficiation technologies. In this regard, detailed characterization of phosphate reserves is crucial to understand textural limitations and help design appropriate strategies to achieve quality products. In this paper, the development of procedures to establish dolomite rejection/francolite recovery curves for gravity preconcentration of pebble phosphate from Central Florida is described using high-speed X-ray computed tomography (HSXCT). The developed procedure is illustrated with the analysis of high MgO pebble phosphate samples (10.39 mm × 1 mm) received from South Pasture and Four Corners locations operated by the Mosaic company. The rejection/recovery curves were calculated for each sample for five different particle size classes to observe the trend in rejection/recovery with variation in particle size. In order to evaluate the reliability of the HSXCT data, analysis using the high-resolution X-ray computed tomography (HRXCT) technique was performed on one particular sample (FC-3-1). Finally, to assess the separation efficiency, the HSXCT and HRXCT rejection/recovery curves obtained were compared to experimental gravity preconcentration results reported in the literature. In this way, liberation limitations for gravity preconcentration in the processing of pebble phosphate have been established based on X-ray computed tomography analysis.

By Daryl R. Tweeton

This Bureau of Mines publication provides information to assist in selecting a lixiviant (leach solution) for in situ uranium leaching. The cost, advantages, and disadvantages of lixiviants currently used and proposed are presented. Laboratory and field tests are described, and applications of geochemical models are discussed. Environmental, economic, and technical factors should all be considered. Satisfying environmental regulations on restoring groundwater quality is becoming an overriding factor, favoring sodium bicarbonate or dissolved carbon dioxide over ammonium carbonate. The cheapest lixiviant is dissolved carbon dioxide, but it is not effective in all deposits. Technical factors include clay swelling by sodium, acid consumption by calcite, and the low solubility of oxygen in shallow deposits. Laboratory leaching tests can provide useful data. However, they can be misleading if, for example, the ore is allowed to oxidize before testing or if distilled water instead of formation water is used for making solutions for permeability tests. Geochemical models presently are more useful for indicating trends in solubility than in reliably predicting concentrations.

Jan 1, 1981

By Olav K1omstad1ien

The lean, but extensive iron ore deposits of the Dunderland Valley north of Mo i Rana, Norway, is the raw material for the Rana Mines which is a division of the state owned steel mill A/S Norsk Jernverk. Activities for the exploitation of the orebodies were commenced in 1902 by the English Dunderland Iron Ore Company. During its operating period the company constructed a total of two large scale concentrating plants. The activities were strongly marked by technical problems and labor disputes. Thus actual production was limited to the years 1904-1908, 1928-1931 and 1937-1939. During these periods a total of 1.9 million tons of crude ore was mined and 0.6 million tons of concentrates produced for export. The present plant commenced operations in late fall of 1964. Up to and including 1976 about 26.6 million tons of crude have been put through the concentrating plant and about 10.7 million tons of concentrate produced.

Jan 1, 1978

By Simon Lekakh, Von Richards, C. Hank Rawlins, Kent Peaslee

"Batch aqueous leaching and carbonation tests were conducted using industrial steelmaking slags to determine the effect of carbonic anhydrase enzyme as a catalyst. Calcium leaching is a strong function of particle surface area, and the extent can be expressed as a function of time and particle size. Carbonic anhydrase did not affect the calcium-leaching rate, however, it did catalyze calcium carbonate formation to achieve a neutralization time near the theoretical rate. Additionally, carbonic anhydrase modified the precipitate morphology due to accelerated particle nucleation. Time controlled tests in which the pH dropped to ~6 decreased the amount of carbonate produced, and this effect was exaggerated by carbonic anhydrase, while pH controlled tests (>8.5) exhibited the highest rate of carbonation. Because the leaching rate was ~50% faster than the carbonation rate, a further increase in the amount of carbonation may be realized by using carbonic anhydrase however pH must be >10.3.IntroductionSteelmaking slag contains high fractions of alkaline earth oxide based phases (i.e., CaO and MgO) that exothermically form carbonates. Thus, it is being considered as a means of permanent carbon dioxide sequestration. At current U.S. steel production rates, approximately 13-17 million tons/year of slag are generated from basic oxygen furnace (BOF), electric arc furnace (EAF), and ladle metallurgy furnace (LMF) processes [1]. BOF and EAF slag is used as high quality mineral aggregate or cement clinker, while LMF slag, produced at ~15% the rate of BOF and EAF slags, has limited use as blast furnace flux or acid mine neutralization with the majority going to landfill [2]. Based on slag’s chemical nature and immediate availability as a co-product from steel production, the steel industry initiated a project to investigate hydrous carbonate formation in steelmaking slag as a method of sequestering carbon dioxide emitted in steelmaking offgas [3]. The goal of this project is to determine the reactor parameters suitable for the design of an industrial system for treating steelmaking offgas with raw or minimally processed slag."

Jan 1, 2009

By M. Polat

A combined heavy medium-flotation process which incorporates the advantages of two widely employed cleaning methods, namely, heavy medium separation and flotation was used to achieve improved separation of coal from ash at fine sizes and to recover the heavy medium as a substantially recyclable product. The investigation was carried out in two successive phases. In the first phase, tests were performed to deter-mine the effect of different variables such as the medium density, flotation time, magnetite type, etc. on the efficiency of the process using in-plant samples from Homer City Coal Preparation Plant. In the second phase, the optimum conditions determined in the first phase were employed to determine the applicability of the process to a few Central Pennsylvania coals. It was observed that the process was very effective in recovering the magnetite. In most of the cases investigated, the magnetite was separated from the non-magnetic material at approximate-1 to 99 % recovery with a grade ranging from 95 to 99 %. The grade of magnetite decreased with increase in ash content of coal and with decrease in size of magnetite.

Jan 1, 1992

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

By Shinzaburo Kato

In 1977 Kawasaki Steel Corporation (KSC) built No. 6 BF (Blast Furnace) with an inner volume of 4 500m3 as part of our program to produce 8.5 million tons of crude steel a year at Chiba Works. As the primary raw material to be used in No. 6 BF, we decided to use sintered ore, because we were confident in the obvious advantages of our technology developed by that time on sintering and BF operation using sintered ore. At Chiba Works, however, we had no space for the construction of a sinter plant, so we decided to build it abroad. Sintered ore is easily crushed and degradated. Producing sintered ore at a point far away from the blast furnace and transporting it across the ocean was the world's first attempt. To successfully realize it, we conducted a series of fundamental surveys and studies with special stress on the real aspects of degradation of sintered ore caused by long-distance transportation and handling and the ways and means to prevent the degradation. As a result, we decided to build a plant on the Mindanao of the Philippines.

Jan 1, 1982

By Mario J. Arenas Figueroa

El presente trabajo señala la formación geológica del yacimiento minero de Julcani, el fracturamiento de esta estructura, como los principales controles de su mineralización. En este sentido, la estructura del yacimiento es epigenético con vetas del tipo de relleno de fracturas en volcánicos Terciarios, caracterizadas por una mineralización en rosario y con valores de plata altamente erráticos. De otro lado, el fracturamiento es complejo puesto que este atraviesa tres periodos, las cuales coinciden con el rumbo de las vetas principales. Los principales controles de mineralización son el tipo de roca encajonante, los diques, intersecciones, etc, señalándose sus características para una exploración sistemática de nuevas vetas y bolsonadas.

Nov 20, 1967

By Ellis S. Hertzog, James R. Cudworth

Tremendous interest has been evidenced in the subject of dewatering and drying ooal for the past 10 years, and yet little effort has been made to summarize the literature, at least so far as this country is concerned. Only a few published articles have dealt solely with dewatering and drying coal. In most cases the subject has been discussed briefly, either in general terms or as to specific installations. It is desirable that a compendium be prepared collecting in one place information on the dewatering and drying of coal, the needs for this process in various fields, the available equipment, and the current American practice in regard to it. This work was underta..lten by the :Bureau of Mines in cooperation with the University of Alabama. New coal-washing plants in which various types of dewatering and drying equipment were in operation were visited in-Pennsylvania; Ohio, India...~a~ and Illinois. The dewatering·and drying of coel has .been studied in this coimtry by the Surface Preparation ·Committee of the ·coal Operato~s• Committee of the .American Mining ·Oongress. In GermaIJY .it has received the special attention of the Reichskohlenr·at, and in Great Britain of the Utilization of Fuel Commi-t-tee of the Insti ti.ite of Min"ing Engineers.

Apr 1, 1938

By R. V. Ramani

In this report, the application of the Open Pit Materials Handling Simulator (OPMHS) to a mine located in Illinois using bucket wheel excavator (BWE) and a stripping shovel in tandem for overburden removal is described. The specific objective of the study is to demonstrate the application of the simulator to analyze mine planning and scheduling problems and to generate and analyze alternatives for increased production. On the basis of the simulations it was concluded that the maximum productive capacity of the system in raw coal was around 3000 tons per shift. At this production level, the equipment combination and availability also satisfy the match requirements for the stripping shovel and the BWE, and the overburden and coal removal systems. Several alternatives requiring new equipment are proposed and analyzed for increasing production. However, no economic analyses of these proposals were done.

Jan 1, 1977

By Joseph A. DeCarlo

The rapid growth of the organic chemical industry in the United States and abroad has focused attention on the future raw-material sources for this important industry. Chemical products are essential to modern civilization; and millions of tons of organic chemicals are used annually, ranging from basic raw materials to finished chemical products such as drugs, cosmetics, and soaps. Hundreds of chemical products are made directly or indirectly from coal, but in this report "coal chemicals" will be limited to crude tar, crud light oil, and ammonia recovered in the high-temperature carbonization of bituminous coal and the important principal products obtained by processing these materials. Specifically these include benzene} toluene, xylene, naphthalene, creosote oil, tar acid oil, pitch, and ammonium sulfate. Therefore the term "coal chemicals", wherever used in this report, includes only these products and does not include the secondary or intermediate products such as styrene, synthetic phenol, aniline, phthalic anhydride, or finished products made from these, such as synthetic rubber, plastics, and dyes. The United States leads the world in production and consumption of coal chemicals. In the past five years nearly one-fourth of the total output of coal-tar crudes in the world was produced in the United States. Consumption of some of the more important products derived from these crudes such as benzene, toluene, xylene, and naphthalene, however, ranged from about one-third to one-half of the world total because of imports and production of benzene, toluene, and xylene from petroleum. The synthetic organic chemical industry of the United States was established during World War I on chemical raw materials obtained by the high-temperature carbonization of bituminous coal but this source of supply currently furnishes less than 40 percent. More than 60 percent of the chemical raw materials used to produce organic and inorganic chemical is supplied by the petroleum industry and production of petrochemicals is rising rapidly.

Jan 1, 1960

"La presente investigación señala los trabajos exploratorios realizados en la superficie del sistema de vetas Santa Úrsula, así como el desarrollo de galerías y cortadas con fines de exploración y profundidad. También se indica el laboreo anterior observado -en tanto superficie como profundidad-, y el laboreo reciente en profundidad. El sistema de vetas Santa Úrsula, ubicado al Sur de las oficinas principales del campamento de las Minas Sucuitambo, Arequipa, comprende dos ramales principales paralelos hacia el NW que se unen hacia el SE, y una serie de ramales secundarios, de escasa potencia, al lado SW, de los principales. Es a partir del afloramiento y el desarrollo de labores en profundidad, que los ramales principales del sistema señalado, ofrecen posibilidades por encima del nivel +40. y se puede revisar el muestreo de todas las labores antiguas para tener un mejor interpretación de los sistemas de veta. "

Jul 20, 1957

Another major aluminum company announced intentions to follow other domestic producers recent price actions by raising its unalloyed ingot quotes by 3¢ to 44¢ per pound, effective June 1, 1976. COBALT: All final data for 1975 are included in the table for cobalt on page 23. Demand in March increased significantly for the second month in a row, signaling a recovery from the previous year's relatively low demand levels. Imports of cobalt tripled in March over those of February. This should partially offset reduced sales of cobalt excesses from the National Stockpile. Import projections for the next several months have been lowered because transportation difficulties in Zaire are expected to result in reduced shipments.

Jan 1, 1976

By C. Díaz

Roast-reduction smelting (RRS) of nickel concentrate, combined with flash smelting of copper concentrate, was one of the process options that Inco considered as a means of meeting its 1994 sulfur dioxide abatement target at its Copper Cliff operations. RRS involves deep roasting the nickel concentrate in fluid bed roasters. The roaster off-gas is heated in a sulfuric acid plant, and the low sulfur calcine is reduction smelted with coke in an electric furnace to yield a sulfur-deficient matte. The latter material is converted to Bessemer matte in Peirce-Smith converters, with minimal evolution of sulfur dioxide, and the converter slag is reverted to the electric furnace. Excellent nickel and cobalt recoveries are obtained. This paper discusses the development of RRS, including extensive commercial scale testing at Inco's Thompson Smelter, and its key operating parameters.

Jan 1, 1993

By V. H. Gottschalk

Sponge iron is a product resulting from the reduction of an iron oxide below the temperature at which the product melts. Commercial grades usually contain 80 to 95 percent metallic iron, 2 to 5 percent unreduced iron oxide, and an amount of siliceous gangue material depending on the pur.ity of the are used for reduction. The reducing agent may be gaseous or solid, and a large variety of procedures have been proposed for bringing the reducing agent into reaction with the iron oxide. Of the proposed procedures, the one that has the distinction of having been in continuous commercial operation for the longest time, from 1911 to date, was developed at a ceramic plant in Hoeganaes, Sweden, and yields? a product that has an enviable reputation as furnace feed wherever special, high-quality steels are made.

Jan 1, 1948

By Iván Espinoza

El yacimiento de Horizonte es un sistema de vetas auríferas de qz ± sulfuros del tipo mesotermal, que está emplazado en el Batolito de Pataz, un intrusivo Mississipiano localizado en el margen occidental de la cordillera Oriental de la parte norte de los Andes Peruanos. En ese sentido, el presente trabajo describe la exploración geofísica realizada en el primer trimestre del año 2008 en Parcoy, con la finalidad de encontrar nuevas zonas de mineralizaciones potenciales y completar el modelo estructural en la zona. Para ello, se elaboró el proyecto de exploración PD para Parcoy, a través del método IP, el cual es usado en la búsqueda de mineralización de oro, así como el uso de sondajes diamantinos a las nuevas zonas detectadas por la geofísica. Como resultado de ello, se determinó 6 zona anómalas de interés prospectivo para ser analizado por el departamento de exploraciones.

Sep 14, 2009

By Karl C. Dean

The current emphasis on environmental problems has focused attention on the massive nationwide accumulations of mine, mill, and smelter wastes that represent potential air and water pollution hazards. The pollution hazards can be reduced or eliminated by utilization or stabilization of these wastes. The U.S. Bureau of Mines, since the inception of the Solid Waste Disposal Act of 1965, has been conducting research to determine the practicality of various utilization and stabilization procedures. Investigations include partial extractions of desirable waste components and full utilization of the wastes as simulated soils or in ceramic or other structural products. Chemical, vegetative, and combined chemical-vegetative methods of stabilization have been actively studied. This report updates information previously developed by the Salt Lake City Metallurgy Research Center and presents the current status of antipollution solid waste work 1/,2/.

Jan 1, 1970

By K. Rajamani

The word adapt means "to change so that one's behavior will conform to new or changed circumstances." Applying this definition to process controllers suggests that an adaptive controller can change its behavior in response to changes in the dynamics and disturbances of the process. In the minerals industry there are many control cases where adaptive control will provide superior control as compared with more traditional PID (proportional, integral, derivative) control. A typical plant uses as many as 100 to 200 control loops for lprocess regulation. Therefore, the task of initially tuning and then periodically retuning these controllers is a formidable problem, During the time the controllers are "un-tuned", product quality may deteriorate and unstable operations may result. Adaptive controllers are capable of tuning themselves, thus avoiding this problem. The computers commonly used in distributed control systems are easily capable of implementing adaptive controllers. In addition to the possibility of using the control computer to implement adaptive controllers, many distributed control systems will offer adaptive control as a standard feature in the near future.

Jan 1, 1984

By August J. Kwitowski

This report presents the results of a joint Bureau of Mines-U.S. Department of Energy project that evaluated a newly developed low-coal mining system: the 4M miniminer system. The evaluation took place from April through October 1981 and determined potential health, safety, and productivity factors for the mining system using the surface test facilities at Bruceton, PA. The planning, testing, results of testing, and a summary evaluation of the 4M miniminer system are included in the report. The miniminer system was found to be a very good concept with future potential for safe, healthful, and economic production in thin-seam mining. The mining system was also judged to have considerable potential for use in some coal seams that are presently considered unminable by other existing mining equipment. The preproduction, prototype version of the miniminer system that was tested suffered from several safety and production problems. These problems are also described, along with suggested remedies.

Jan 1, 1989