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By M. Abdellatif

Successful demonstration of The Mintek Thermal Magnesium Process (MTMP) was achieved in November 2004 at the pilot-scale, About 30 tons of magnesium producing recipe was smelted in the DC arc furnace over a continuous operation of 8-days, Twenty-two furnace batching-tapping operations were carried out at a feed rate of 525kg/h and a smelting temperature of 1600-1700°C, The MgO content in the produced slag was as low as 6,7%, and averaged 9,2% MgO, resulting in an overall magnesium extraction of 77%, which reached 87% during good operating periods, Magnesium vapour was extracted at a rate of 70-85kg/h and was delivered to the condenser that was operated at 680-720°C, The magnesium was captured in the condenser crucible in a liquid state, allowing its prompt tapping, More than 3500kg of crude metal were produced over 15 on-line metal tapping operations, On average, a condensation efficiency of 85% was achieved during the entire testwork, which peaked at 87% during steady operations, The quality of the crude metal was similar to, if not better than, that of the Magnetherm's crude magnesium, A pre-feasibility study has indicated that the MTMP has the potential for lower capital and operating costs as compared to the electrolytic process, and therefore Mintek and its consortium partners are exploring opportunities for a commercial production facility.

Jan 1, 2006

By B. J. Moore

This publication contains analyses and related source data for 234 natural gas samples from wells and pipelines in 21 States and 1 foreign country. All of the samples were obtained and analyzed during calendar year 1975 as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and n special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the public in general. Seventeen previous publications have presented the results of 10,831 gas analyses prior to 1975. The first 3, Bulletins 486,4 576,5 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 14

Jan 1, 1976

By Edwin G. Sharp, Frank S. Gaunce, George M. Freeman, Denis J. Kemp, Eric Dulson, Paul Salmon, Ernest R. Hamilton, Carl E. Parden

"THE ECSTALL ZINC PLANT was built for the treatment of the Kidd Creek zinc sulphide concentrates. Construction proceeded throughout 1970-71, with operations beginning in April 1972. The two concentrate types treated differ principally in minor impurity and precious metal contents. Processing flexibility was required to allow efficient recovery of the by-products, especially cadmium, copper and silver. The conversion of the zinc sulphide concentrates to end products follows a sequence of operations that are common to most electrolytic zinc plants and typical of the ""Tainton- Jephson"" flowsheet.1. Roasting in air at an elevated temperature to convert the metal sulphides to soluble metal oxides (calcine) and sulphur dioxide. The sulphur dioxide is converted to sulphuric acid in a contad plant and shipped by train to market.2. Leaching of the calcine in spent electrolyte to effect extraction and recovery of zinc as zinc sulphate solution, leaving an insoluble residue.3. Purification of the clarified zinc sulphate solution by cementation with metallic zinc dust to remove impurities detrimental to the electro-deposition of zinc or detrimental to product purity. The solids from cementation are the starting materials for secondary metal recovery.4. Electrolysis of the purified zinc sulphate solution to reduce the zinc to the metallic state while coincidentally regenerating the sulphuric acid for recycle to the leaching step."

Jan 1, 1974

By Harold J. Bennett

The purpose of this study was to develop methods for the financial evaluation of mineral deposits. This includes the selection of the best alternative mining and processing methods and production rates. This was done by performing a financial evaluation through computer simulation using sensitivity and probabilistic risk analysis. The criterion used to measure the relative advantages of these investment and operating alternatives is the discounted-cash-flow rate of return. Included is a description of the theory and methods used in the probabilistic analysis approach, which is based on the premise that the expression of a range of values in establishing an estimate for a parameter is more realistic than the choice of a single value. Numerous simulations are made using randomly selected values of the input parameters resulting in a frequency distribution of the rates of return and their relative probability of occurrence. The sensitivity analysis method is described and combined with the probabilistic analysis to interrelate mineral reserves, capital investments, operating costs, and production rates. The ability to vary these input parameters on successive runs has permitted the selection of the best alternative mining and processing methods and production rates for a given mineral deposit. For illustrative purposes the evaluation of a mineral deposit was performed using three alternative mining and processing methods at three different quantities of resources and various production rates and prices. The computer program used in this analysis was written in FORTRAN II for maximum compatability and should run without modification on most computers having BK (8,000-word) core memory, a card reader, and printer (120 characters per line).

Jan 1, 1970

By Paloma Lazaro, Moe Momayez

Heat-related illnesses (HRI) are relatively common in both hot surface and underground mining operations. When workers are exposed to extreme heat or strenuous work in a hot environment, they become prone to heat stress. Heat strain is the result of the body’s response to external and internal heat stress. It is therefore vital for the conditions leading to heat strain be detected and treated in a timely manner. Heat-related illnesses are manifested by exhaustion and heat stroke. The predicted heat strain (PHS) [ISO 7933 (2004)] model has been developed to predict the health condition of the worker in terms of core body temperature and water loss. The PHS model tested in this study is based on eight physical parameters that are measured at different intervals during a work shift. They include air temperature, humidity, radiation, air velocity, metabolic rate, clothing insulation, posture, and acclimatization. The model predictions are then compared with a direct physiological measurement, such as core body temperature. We present the results of an extensive study that monitored and predicted body’s response to heat stress under different environmental and working conditions. The PHS model provided reliable results in most instances in comparison with other prediction methods currently in use in the field.

By W. B. Morrey

This paper deals with the development of the new cap-sensitive slurry explosives. The history and special features of these explosives are outlined, and recent field trials are described.

Jan 1, 1973

By S. Kodama

Starting on a small scale, the equipment for processing synthesis gas to form liquid hydrocarbons was expanded to handle 100 m) 3/hr. This reactor was successfully designed and constructed, and a basis for future design methods was established. Because, however, this work was carried out on an empirical basis, it is felt that a more thorough theoretical study should be made in an effort to increase the efficiency of the process, particularly in the development of a simpler converter.

Jan 1, 1951

By José R. Parga

In some parts of the Comarca Lagunera with population of about 2.5 million people, situated in the central part of northern México, chronic arsenic poisoning is endemic and severe adverse effects attributed to As exposure have been reported. Lifetime exposure to arsenic will develop classical symptoms of arsenic poisoning such as skin pigmentation changes, gastrointestinal disturbances and neurological changes. There are several methods available for removal of arsenic from well water in large conventional treatment plants, however a very promising electrochemical treatment technique that does not require the addition of chemicals or regeneration is Electrocoagulation (EC). The EC operating conditions are highly dependent on the chemistry of the aqueous medium, especially conductivity and pH. In this study, Powder X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Mössbauer Spectroscopy (TMS) were used to characterize the solid products formed at iron electrodes during the EC process. This study will provide an introduction to the fundamental concepts of the EC method. Finally the results of this study suggest that the presence of maghemite and magnetite particles can be used to remove arsenic (III) and arsenic (V). In the field pilot plant scale study more than 99% removal of As species from groundwater is achieved.

Jan 1, 2005

By Paloma Lazaro, Moe Momayez

Heat-related illnesses (HRI) are relatively common in both hot surface and underground mining operations. When workers are exposed to extreme heat or strenuous work in a hot environment, they become prone to heat stress. Heat strain is the result of the body’s response to external and internal heat stress. It is therefore vital for the conditions leading to heat strain be detected and treated in a timely manner. Heat-related illnesses are manifested by exhaustion and heat stroke. The predicted heat strain (PHS) [ISO 7933 (2004)] model has been developed to predict the health condition of the worker in terms of core body temperature and water loss. The PHS model tested in this study is based on eight physical parameters that are measured at different intervals during a work shift. They include air temperature, humidity, radiation, air velocity, metabolic rate, clothing insulation, posture, and acclimatization. The model predictions are then compared with a direct physiological measurement, such as core body temperature. We present the results of an extensive study that monitored and predicted body’s response to heat stress under different environmental and working conditions. The PHS model provided reliable results in most instances in comparison with other prediction methods currently in use in the field.

By Ernest W. Johnson, F. E. Cash

"INTRODUCTION Mine operators have long realized the importance of providing a satisfactory and dependable means of giving prompt warning to underground mine workers at the occurrence of a mine fire or other threatened disaster.Most underground mines of the Lake Superior district are prepared to inject a stench liquid into the compressed-air system quickly to give such warning. The liquid evaporates quickly and gives off an intense and easily recognizable odor even when present in minute quantities in the mine air. Workers in the mines studied have been fairly generally familiarized with the odor and instructed as to evacuation procedure when the warning odor is detected.In some mines provided throughout with electric lighting, including working faces, a prearranged light-flashing signal is given as a warning supplementary to that received from the stench.In a few mines, workers have been instructed to evacuate the mine immediately in the event the compressed-air supply is cut off, regardless of whether mechanical failure may be involved.Information obtained in observing a number of stench-injection tests is compiled and presented in the hope-that it will serve as an incentive to provide means of making stench injections at mines not now so equipped and for making similar tests at other underground mines, so that in case unsatisfactory results are obtained rectifying adjustments or changes may be made in time. It is further hoped that this paper will bring out the real importance of repeating these tests from time to time, at least once a year on each operating shift, so that in the event of an actual emergency, underground employees will receive a prompt warning."

Nov 1, 1945

By Sara Swiokla Korsikas, Toren Olson, Amado Guzman, Yuri O. Zepeda P

Ore agglomeration has been used as part of the heap leaching process for the last 40 years. However, industrial experience shows that the lack of a universal agglomeration standard has limited the benefits of this, otherwise, valuable unit process. The more complex the ore, in terms of the nature and relative abundance of fines (<74 μm), the more important that the agglomeration product satisfies some minimal requirements. This paper presents an agglomeration scale that identifies the quality standards for agglomerates and documents the resulting mechanical, physical, and hydraulic (hydrodynamic) behavior associated with each level on the agglomeration scale. The hydrodynamic properties of an agglomeration product are critical for the proper design of a leaching operation and, as shown in this paper, can be used to select the optimal pretreatment method for a given ore sample. Agglomeration as a unit process not only allows better conditioning of the hydrodynamic behavior of the ore but also creates an opportunity for optimized delivery of reagents to kick-start the leaching process which may ultimately improve the economic performance of leaching. Industrial case data is used to demonstrate the shortfalls associated with low-quality agglomeration and the benefits of improved agglomeration which range from enhanced porous structure (better percolation and drainage characteristics) to better metallurgical response (faster kinetics and higher metal recovery). Proper agglomeration has been used to render otherwise untreatable ores into valuable leaching resources.

Feb 9, 2024

By K Saito, M Hasegawa

In steelmaking processes, it is known that P2O5 in dephosphorisation slags often exists in solid solutions between Ca2SiO4 and Ca3P2O8, <C2S-C3P>SS, and thus the solid solutions play an important role in the dephosphorisation reaction. Hence, the knowledge of thermochemical properties, ie phase relations and activities of components, in slags containing <C2S-C3P>SS are necessary for the effective removal of phosphorus from hot metal. In this study, the P2O5 activities in <C2S-C3P>SS were measured through the gas equilibrium method. In the present experiment, oxide samples were equilibrated with Cu-P liquid alloys at 1573 K under a stream of Ar + H2 + H2O or Ar + H2 + CO2 gas mixture in which oxygen potential was fixed and then equilibrium phosphorus concentrations in the Cu-P alloys, [mass%P]Cu, were analysed with ICP-OES.

Aug 21, 2024

By Jay A. Carpenter

IN six years the construction of Hoover Dam and the power plants probably will have reached the operating stage and this vast new source of power will then be continuously available for industry. The height of the darn will be 580 ft. and the average annual flow of the Colorado River is calculated at approximately 24,000 cu.ft. per sec. If this full head and average flow can be maintained the year round, about one million horsepower will be generated. The U. S. Reclamation engineers, taking into consideration the probable range in flow and head, have set the figure for power contracts at 660,000 firm horsepower, which can be assured at all times of the year. During the months of heavy run-off of water from the Colorado River Basin the power plants should be able to generate the full 1,000,000 hp. capacity of the power plants, so there will be 340,000 excess or secondary horsepower. The cost of firm power at the switchboard will be close to 2.15 mills per kw.-hr., equal to $14.05 per hp.-yr., and the cost of the secondary or off-peak power will be close to 0.8 mills per kw.-hr., or $5.22 per hp.-yr. In no place in the country can such cheap power be obtained today. The electrochemical industry is in a state of flux because the power costs from its old sources have increased so much (to $30 per hp.-yr. at Niagara) that the industries have had to seek new sources, so they have gone to Canada and Norway and built new plants.

Jan 1, 1932

By M. P. Meehan

The purpose of this paper is to present the Anamax Instrumentation Department&apos;s: responsibilities, organization, preventive maintenance, test facilities, training and applications. The Anamax Mining Company is a general partnership between AMAX Arizona, Inc. (a subsidiary of AMAX INC.) and The Anaconda Company (a subsidiary of Atlantic Richfield). Anamax&apos;s product and by-products include: copper, molybdenum, and silver; uranium is to be added as a by-product in early 1980.

Jan 1, 1980

By W. J. Mitchell

During the months of April and May 1992, the Phelps Dodge Hidalgo smelter underwent a major turnaround. This was the third such turnaround in the life of the facility which was commissioned in 1976. During the third furnace campaign, the smelter processed 5.2 million tons of concentrate producing 2.6 billion pounds of anode copper over a 7.5 year period. The critical path on the fifty-nine (59) day turnaround schedule was the reconstruction of the Outokumpo flash furnace which integrated some modifications with standard rebuild practices. Modifications included incorporation of horizontal cooling jackets throughout the furnace settler as well as the installation of castable refractory in the reaction and uptake shafts.

Jan 1, 1993

By T E. Tibbetts

This paper deals with coal sampling in general and with mechanical coal sampling in particular. The necessity of obtaining representative samples is emphasized. Other sections of the paper are devoted to the design and selection of automatic samplers, with a consideration of the three main types, and the testing, operation and maintenance of these samplers. The cost of the installation of an automated sampling system must be related to the value of the material to be sampled, to the volume of coal involved, and to the savings in labour and economy which can be achieved. Introduction T HE Committee?:; on Coal Sampling of the Coal Study Subsection, Thermal Power Section (Eastern Zone), Canadian Electrical Association, was established in November, 1963, to "study the various problem areas of coal sampling." The first undertaking of the Committee was to at-tempt to survey the problem areas of coal sampling through an evaluation of coal sampling difficulties as experienced at both the plant design and operational levels within the electric utilities represented on the Committee. The results of this enquiry indicated that satisfactory answers to almost any conceivable

Jan 1, 1965

By Cadwallader Evans

MY endeavor in this paper will be to tell something of the accomplishments and current problems of the anthracite producer and to suggest some of the avenues for technical development that seem to me to be the most necessary and likely to bear fruitful results. The several subjects, that I find of most interest will be taken up individually with brief reference to the future trend. Underground Mining and Loading ?In this field great progress has been made in the last twenty years, beginning with the introduction of the scraper system. The electrical hoists for the operation of scrapers have been improved, and give little trouble, but there is an open field for the improvement of the auxiliary apparatus, particularly in the application of roller-hearing sheaves to the guiding of scraper ropes. Also notable in the last six or seven years is the introduction of shaker chutes, so that far more anthracite is now loaded over them than by scrapers. This trend should continue to be manifest, particularly if those who are looking ahead and who are charged with the development of this specialty continue constantly to study and improve the mechanical design of their shakers.

Jan 1, 1938

By John Nagy

Dust explosion data obtained in laboratory studies by the Bureau of Mines are presented for activated carbon, asphalt, charcoal, carbon black, coal, coke, gilsonite, graphite, lignite, miscellaneous carbons, pitch, tunnel dust, and mixtures of these materials with other ingredients. The explosion hazard is shown to increase as the volatile content of the dusts increases.

Jan 1, 1965

By G. W. Barton

Process Systems Engineering (PSE) can be defined as the integrated usage of computer-based design and analysis tools. As such, PSE is becoming increasingly important in the chemical and petrochemical industries. This paper shows how a range of PSE techniques have been applied to the zinc electrowinning process. Topics discussed include model development, parameter estimation, steady-state and dynamic model applications, steady-state optimisation and neural network modelling.

Jan 1, 1994

By John G. Hall

The unstable metal market during 1949, with resulting lower metal prices, has focused every mine operator&apos;s attention on the problem of reducing operating costs. Improvement in mining, methods, use of modern mechanical mining equipment, and increasing the efficiency of the labor force are the tools with which we will have to work. Careful planning is necessary to coordinate all phases so that no one phase is overdone. A mine may become over-mechanized if, for instance, capital charges against new equipment exceed the savings in labor costs, or where a large enough tonnage is not produced. The cooperation, of labor is essential to any mechanization program. There have been too many instances where mechanization and improvements have done nothing more than make up for a decrease in labor efficiency, thus bringing the production of labor back to its old standard. The operator has gained little and labor has gained only a "softer job." In any mechanization program there are gains to be had by both the operator and labor. By the efficient application of modern equipment and improved mining methods the operator should gain by decreased costs, and labor may profit by receiving a share of these decreased costs.

Jan 1, 1950