Search Documents

By K. J. Richards, W. J. Schlitt

A combination of industrial and laboratory data is used to explain the interrelationships between operating parameters and cementation plant performance as measured by copper recovery and iron consumption. The chemical factors considered are the relative concentrations of copper and ferric ions in solution, acid concentration, the possible buffering action of other dissolved salts and solution temperature. The effects of flow conditions, solution oxidation, the presence of metallic copper and retention time are also considered. Based on the various relationships developed, possibilities for plant optimization are discussed.

Jan 1, 1974

By Donald N. H. Chi

The unsteady, one-dimensional, compressible-flow equations have been solved numerically for a deflagration propagating through a gallery of finite length closed at the ignition end and open at the opposite end. These equations were solved for two situations wherein (1) the propagating flame was extinguished after 0.1 sec or before the return of aerodynamic disturbances reflected from the open end, and (2) the flame was allowed to propagate a full 0.8 sec until it was extinguished. It was found that the process of sudden flame extinguishment creates rarefaction waves that, upon entering the burned zone, produce resonance within the burned cavity. For the relatively small value of the product of the expansion ratio (8.5) and the effective burning velocities of 7.4 m sec-1 for the first experiment and 4.9 m sec-1 for the second experiment, it was found that the acoustic approximation provides an adequate estimate of the pressures developed ahead of the flame during the system's early history.

Jan 1, 1974

By D. R. Dixon

Since the critical role of oxygen in xanthate flotation of sulphides was established (1) subsequent studies have been concerned mainly with the galena-xanthate system. It is therefore surprising to find at the conclusion of a comprehensive review of the topic by Granville, Finkelstein and Allison (2) that it was not possible for them to draw unequivocable conclusions on the mechanism of xanthate adsorption. It was apparent that some new advances were likely if systems other than galena-xanthate (Pbs/x-) were examined. (2) Specifically a less reactive sulphide such as ZnS may interact with flotation reagents at a slower rate than PbS and more information per unit time gathered. Again ZnS is far less reactive electrochemically than PbS or stated equivalently, it is a poorer semiconductor than PbS. More importantly, the ability of ZnS to act as a semi-conductor can be controlled photochemically rather than by direct doping reactions for which it is difficult to assess the uniformity of doping. Thus the conductivity of ZnS can be made the same as that of PbS by irradiating the ZnS with ultraviolet light at circa 360 n.m. (3)

Jan 1, 1974

By H. J. Lechtenberg

This Bureau of Mines report investigates solvent injection as a means of increasing oil production from low-gravity oilfields; thus, wells in two California oilfields that produce from reservoirs having low-gravity oil were injected with highly aromatic solvents to increase their oil recovery. The wells were either allowed to soak or the solvent was circulated for a period of time. In some of the wells, the solvent was followed by a slug of water. The post-stimulation production rate was considerably higher than the prestimulation rate of the wells. Wells in which the solvent was not followed by water showed an immediate increase in oil production, and essentially all of the solvent was recovered. The wells in which solvent was followed by water essentially showed a delay in the increase in oil production, thus indicating a temporary water block. The results show that the production rate is usually increased by the injection of solvent, and the method may prevent early abandonment of marginal producers. Cumulative post-stimulation oil production indicates that cyclic solvent injection treatment can be an economic success.

Jan 1, 1974

By W. H. Eddy

The Bureau of Mines conducted laboratory batch-and small-scale continuous flotation processing tests on waste granite fines from Georgia, to determine the feasibility of recovering usable feldspar and quartz products by flotation. Two flotation methods were utilized for the removal of biotite and other iron-bearing minerals: One was in an acid-cationic circuit, and the other in an alkaline-anionic-cationic circuit. Feldspar was recovered using an acid-cationic method. To produce commercial-grade feldspar and quartz products it was necessary to employ either two sequential froth flotation circuits or one froth flotation circuit supplemented by wet-magnetic separation techniques to remove iron contaminants. Continuous flotation processing yielded a commercial-grade feldspar concentrate containing, in percent, 3.8 Na20, 5.4 K20, and 1.10 CaO, with recoveries of 77.8, 70.3, and 64.4, respectively. The feldspar tailing was high-quality glass sand containing 98.2 percent SiO2 and 0.024 percent Fe2O3. About 42 percent of the quartz was recovered at glass sand specifications. An effective separation of, potash feldspar from the bulk feldspar concentrate was achieved by batch flotation in a mineral separation cell.

Jan 1, 1974

By Charles R. Marek

There is an ever-increasing need for quality construction materials to provide the necessary housing and transportation facilities required for the protection and movement of people and goods. By the year 2000, requirements for housing in the United States will have doubled due to population growth. Requirements for transportation facilities in this same period will also have increased substantially. Further, all existing facilities for both housing and transportation will require substantial maintenance of one form or another. Aggregate is the basic material of the construction industry. There is some occurrence of aggregate source material in virtually every state of the United States, and in every country in the world. United States reserves of commercially useable aggregate have never been systematically estimated and are probably so vast as to be incalculable.1 However, in many areas its existence is largely negated by inaccessibility. Often it is lodged deeply or intricately in the earth or it is too distant from markets to offer a desirable "return on investment" under the present economic structure. Other factors that prevent its utility are the occurrence of small scattered deposits that individually are too small to justify the necessary capital investment for exploitation and collectively are too widely disseminated; also, the aggregate nay be deficient in certain desired chemical or physical qualitites.1

Jan 1, 1974

By Howard E. Parkinson

The mine pager phone to public telephone interconnect system permits mine paging telephones to be interconnected with the public phone system, thereby providing emergency and off-hours communications. The system, a push-to-talk, push-to-listen system, is compatible with any mine paging system utilizing dc voltage on the line to enable paging. A tone generator of the proper frequency enables an outside caller to page over mine pager system loudspeakers. A caller inside the mine can make an outgoing call to a preselected, preprogramed number with the use of a proper frequency tone generator. The system includes an automatic hangup timer that restricts the time off-line due to a wrong number or incorrect hangup to 20 seconds and 6 minutes, respectively.

Jan 1, 1974

By W. L. Dare

Land use planning is not a new concept in the United States but the emphasis has changed drastically since the early 1960's. Under the old interpretation we tried to expand our frontiers and develop our land, but as society has become more affluent and mobile the demand has grown to preserve those parts remaining undeveloped. There is something of a paradox inherent in this change of emphasis. While affluence has motivated our support to preserve the quality of the natural environment, industrial development is needed to support the affluence. Because we cannot accomplish all of each, sound planning and compromise will be necessary since it is unlikely that, the American people will want to surrender much of their life-style or their awakening environmental concern. Any industrial society, whether a goal reached or an aim yet ahead, is built largely on the use of mineral raw materials and energy, the physical base of nearly all activities and products. The standard of living which is important to us all is growing more dependent upon these minerals, metals, and energy fuels. Although reduction in consumption of raw materials may be acceptable to those at a certain economic level of a society, those who have not reached that level cannot be expected to accept a lowering of their present or anticipated standard of living.

Jan 1, 1974

By C. B. Manula, R. L. Sanford, R. A. Rivell

The large amount of computer code required for this simulation model dictates that reasonable limitations be placed on some of the input variables. The program permits the following maximum sizes: 1. Ten mine car stations 2. Twenty track intersections 3. Three hundred mine cars 4. Eight motors 5. One hundred profiles 6. Twelve intersections between stations 7. Forty-five profile changes between stations 8. Thirty station pairs (routes) These may be changed by the user providing the particular computer in use has available core storage. Major Array Descriptions This section is a detailed description of four of the major arrays used in the rail haulage simulator for data storage and logical control. Other arrays are used; however, they may be considered sub¬servative to the major ones. These major variables are explained on the following pages. Motor Control Array (XXXDEF). The first 99 locations in this array are arranged according to and are developed by data input. Unit conversions are made at input time which include: 1. Tons to pounds. 2. Rolling resistance in pounds/ton to percent/100. 3. Miles per hour per second (mphps) to feet per min. per minute. 4. Miles per hour to feet per minute. The following information is stored for each motor at the array

Jan 1, 1974

By R. L. Curfman

From January 1, 1965 through July 5, 1970, the very difficult potash ore body of Texasgulf Inc. near Moab, Utah was mined by conventional methods. The mine was gassy, the temperature was high and structural conditions precluded a satisfactory or economical extraction ratio due to the undulating configuration of the ore horizon. In 1966, 67, and 68, alternative mining methods were considered, among which was solution mining of the ore body. Cost studies indicated that the use of crystallizers to evaporate the large amounts of water attendant to solution mining offered no chance of economic success. In 1969 additional testwork and cost studies were carried out utilizing solar evaporation. These studies showed economic potential and justified additional investigation. As a result of these studies, Texasgulf now gathers potash solids from these solar evaporation ponds, (Fig. l), after pumping them from the underground mine as brine. The investigations were concentrated in four basic areas : (1) area evaporation rates and crystal growth habits; (2) underground solution tests including heat transfer rates; (3) accelerated evaporation tests to provide material for metallurgical testing, and (4) tests of evaporation pond lining materials and application techniques, along with area surveys to ascertain if sufficient earth was available in the near vicinity to con-

Jan 1, 1974

By Russell E. Griffin

Dielectric constants and dissipation factors were measured by the Bureau of Mines for 13 simulated lunar rocks over the 20-to 100-megahertz frequency range by means of the susceptance-variation method. Measurements were made at room temperature and normal atmospheric pressure. Results are presented and some comparison is made with data reported by others. The rocks used include a broad range of physical characteristics and chemical compositions from the large areas of volcanism in Oregon and northern California, and two nonvolcanic types. These rocks make up a suite of rock standards used by a group of laboratories engaged in lunar research. The data presented will add to the basic scientific and engineering knowledge needed to utilize extra-terrestrial mineral resources for support of future space missions.

Jan 1, 1974

By Frank Pilotte

Proper design characteristics for a seismic system to locate miners during a mine disaster are considered in terms of a total system concept. Field hardware, processing equipment, operating personnel, deployment, training, and supportive R and D are necessary elements of the total system. Each of these elements is discussed and an indication given as to the requirements necessitated by each one. Hardware must be portable, rugged, and fieldworthy. Processing equipment must be simple to operate, expandable for future processing improvements, and ruggedized for field use. A small well-trained team must be available for quick response in times of emergency. Alternative deployment procedures are necessary to allow for a variety of situations including both ground and air delivery. Supportive R and D is used to support training and upgrading of the system.

Jan 1, 1974

By Richard L. Sanford

The generalized rail haulage simulator described in this paper is an outgrowth of the need to expand a previously developed single level simulator to permit analysis of production problems where intermediate car storage is used. Many of the ideas of the former single level simulator, which is an integral part of an Underground Generalized Materials Handling Simulator (UGMHS), have been used in model development. In addition, experience gained in applying the earlier model to a variety of operating conditions has been heavily relied on. The generalized rail haulage simulation model can operate as an independent system and, as such, can be used to analyze rail haulage systems using production distributions as data input. In addition, this model is designed to replace the present rail haulage sub-assembly in the UGMHS model and the linking procedure has been integrated into the model. The flow of coal from production sections in UGMHS, for example, fill the mine cars and a condition of no empty cars at a loading station will shut down in by production systems.

Jan 1, 1974

By Ronald D. Hill, Elmore C. Grim

The cost of reclamation can vary widely, depending on the primary objectives of the restoration activities. statistics in this study originated from State files, publications, and personal communications relating to restoration and pollution control measures for previously mined lands (orphan lands) and active mines. Reclamation of orphan lands is generally considered a public burden and constitutes an economic problem. All work reported here was completed under government contract, by the lowest bidder, with money coming from State and/or Federal funds. Cost would have been substantially lower had the reclamation been concurrent with mining. Several persons connected with some of the projects have observed that costs could probably be reduced by at least one half, if the reclamation had been conducted along with the mining. The expense of clearing and grubbing of volunteer vegetation, disposal of buried trees and brush, loosing of compacted spoil, and re-establishing access to areas could be saved. In addition, a contracting firm doing the work for a government agency would have mobilization costs and receive a profit. Mining companies also are profit conscious and would consider these costs in anticipating their profits (e.g., overhead would be less if reclamation is integrated with mining). The data presented here should serve as a guide for estimating and determining cost ranges, however, it should be recognized that variations exist. Adjustments may be necessary from the standpoint of physical conditions, economic conditions, price changes, and more restrictive requirements of recent surface mining laws. Reclamation conditions, procedures and successes in the eastern United States, particularly in Appalachia, have no bearing on conditions to be expected in the western United States. The situations are wholly different. Reclamation in the West differs from th t in the East, primarily because of aridity especially a during the summer months 1). Because of the many variables and differences between reclamation in eastern and western areas, they will be discussed separately.

Jan 1, 1974

By Charles H. Ricker

Simulation models have been widely used to analyze the operations and characteristics of a variety of systems. Such models mimmick a projected reality by analyzing the interaction of the events, transactions, and facilities which combine to make up the system. The models are structured as a computer representation of the system components and their logical, precedence and timing relationships. The operation of the system is then simulated over some finite time interval to gather analytical and staistical data. This paper presents a method whereby bulk handling systems, either actual or proposed, may be analyzed by means of simulation models to project the enconomic consequences which may be expected from the system over some future time interval. An example is given to illustrate the construction of bulk handling simulation models, the derivation of performance data, and the analysis of the information with an eye to effective decision making.

Jan 1, 1974

By G. W. Eiger

Bureau of Mines laboratory tests show that ilmenite concentrates with titanium dioxide contents as low as 33 wt--pct can be beneficiated to produce a crystalline substitute for natural rutile suitable for direct chlorination. The synthesized product prepared by a three-step procedure was comparable with natural rutile in titanium content. Reduction smelting of ilmenite removes iron as a pig iron byproduct, and the remaining slag phase is greatly enriched in titanium. Oxidation of the slag in the presence of phosphorus¬bearing slag additive converts the titanium-bearing phases to discrete rutile crystals and a glass phase containing most of the associated impurities. Rutile is separated from the glassy impurities by attrition scrubbing ground slag in dilute phosphoric or sulfuric acid solutions. Tests made in a laboratory fluid-bed reactor show that synthetic rutile responds to chlorination at the same rate as natural rutile and that more than 95 pct of the titanium contained in the feedstock was extracted as titanium tetrachloride.

Jan 1, 1974

By Hsu-Hui Hsing

In several previous studies from this laboratory (1-4) the autophobicity concept of Zisman and co-workers (5, 6) has been extended to gas phase adsorption processes. Low molecular weight alcohols adsorb on silica or alumina to yield novel isotherms in that monolayer adsorption occurs at low relative pressures indicative of strong bonding, but subsequently multilayer adsorption is quite sparse and diminishes with molecular weight of the alcohol. Such isotherms fit no standard classification scheme, however, in the vacinity of monolayer coverage alcohol isotherms give an excellent fit to the Langmuir or B. E. T. , Type I model (7). Monolayer adsorption is relatively irreversible and it is thus possible to prepare these chemisorbed layers and perform subsequent adsorption studies thereon. All indications are that the adsorptive properties on such films is radically different from that on the underlying alumina (4, 8) and in one study finite contact angles for hydrocarbon fluids were observed. One perennial conceptual difficulty is that there is no observed upper bound to the adsorption isotherm which would be necessary for autophobic adsorption to occur. The cause for this has been studied, and it is currently believed that adsorption is complicated by reversible capillary condensation at contact points between powder particles. The evidence for this is that large particle powders give less "apparent" adsorption at high relative pressures and in one very tedious study adsorption on planar sheets, oxidized aluminum displayed similar reduced uptake at high relative pressures when compared with high specific surface area powders (3).

Jan 1, 1974

By A. J. Williams

"Whenever a decision is made to bring a mineral deposit into production, the Owner in actual fact has decided to convert substantial sums of capital into productive capacity with the intenti6n of making a profit from such conversion.Escalating costs of construction, frustrating and costly delays in comp1etion, the increasing tempo of technological change and the increasing size and complexity of mineral processing projects have convinced Owners that the best way of implementing their capital must be sought and utilized. This requirement has stimulated a search for ways and means of applying modern management techniques to the design and construction of mineral processing plants.This search by consulting firms has resulted in the evolution of the concept of project management and the development of planning and con trolling techniques with the result that Owners can seek and obtain better assurance that their project objectives will be fulfilled.This paper will attempt to outline how a mineral processing plant can be brought into production through the implementation of project management techniques.Definition And Objectives Of Project ManagementThe design and construction of mineral processing plants is subject to the restraints of three inter-related parameters -Quality, Cost and Time each of which influences and is influenced by the other two.Project management is a technique where the Owner delegates complete responsibility to a single organization for all phases of a project (design, procurement, construction and commissioning) for the above parameters but retains freedom for major decision making. Normally, the consultant under-takes full responsibility for all phases, but partial project management services can be provided when the Owner so desires.The objective of project management is first to devise and define and then to implement a program in which the relationship between the three parameters of Quality, Cost and Time is optimized, i.e., the desired functional and other requirements are attained (but not exceeded) at the lowest practicable overall cost in the shortest practicable time. The measure of success of a project lies in the degree to which this objective is achieved."

Jan 1, 1974

By L. C. Marchant

Results of detailed analyses of four cores from the Threemile Canyon area in the P. R. Spring tar sand deposit in Utah are reported by the Bureau of Mines. The cores were obtained by the Utah Geological and Mineralogical Sur-vey as part of a l7-corehole evaluation program in the P. R. Spring, Hill Creek, and Rim Rock tar sand deposits. Average properties of the oil zone in the Threemile Canyon area as deter-mined from these cores are as follows: Oil saturation, 67.4 pet of pore volume; porosity, 29.2 pct; permeability before oil extraction, 133 millidarcies; and permeability after oil extraction, 2,855 millidarcies. Average net thickness of the oil zone is 23.8 ft and average depth to the top of the oil zone is 189 ft.

Jan 1, 1974

By Clyde L. Smith

Since the early 1950's exploration in the Yukon Territory, Canada, has been confined largely to Selwyn basin where at least five large stratiform or massive sulfide Pb-Zn deposits have been discovered. The five ore bodies total nearly 100 million tons of 10-16% combined Pb-Zn with 1-3 oz./ton Ag. The only deposit currently in production is the Anvil Mine operating at 8,000 tons per day. Beginning in 1972, exploration in the Mackenzie Mountains, east of Selwyn basin and west of Mackenzie arch, resulted in finds of Mississippi Valley type Zn-Pb mineralization in a belt of Proterozoic and Lower Paleozoic carbonate rocks (Figure 1). Four districts have been located and intensive exploration by numerous Canadian and Arnerican mining companies is currently in progress over a length of 400 miles in the carbonate belt. The consensus is that a major new Zn-Pb province may be taking shape.

Jan 1, 1974