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By D. J. Crawford

The Lucerne Valley Operations of the Minerals, Pigments and Metals Division of Chas. Pfizer & Co., Inca, are located about 5 miles south of the town of Lucerne Valley, California. These operations consist of several limestone quarries, a whiting plant which produces finely pulverized limestone products, a-kiln which produces granular quicklime and lime products, and maintenance shops, warehousing, shipping, and office facilities. Construction of the Lucerne Valley plant began in 1961 as the result of a decision to utilize large undeveloped reserves of limestone in that area. Quarry development was started in the following year; and by 1965, Lucerne Valley had become the principle limestone and lime facility of the Western Operations of the Minerals, Pigments and Metals Division.

Jan 1, 1967

By James Paone

This report shows the feasibility of predicting drillability, analytically, by using regression analysis techniques. The approach is new in diamond-drilling research. Further, the study shows that this technique may be of value to drill manufacturers and others in mathematically delineating performance characteristics of new drills in specific rock types. Another application might be the prediction of penetration speeds in extraterrestrial material based on the physical properties of the materials as samples become available. Prediction equations for penetration rates are presented for 9 rocks drilled in the laboratory and for 20 rocks drilled under field conditions. The prediction equations are based on drill operating parameters and on characteristics of the rock penetrated. No single physical property appeared consistently in the best predictor equations, and all the physical properties were found to be highly correlated with each other.

Jan 1, 1966

By J. S. Hu

FTIR spectroscopy has been used for the characterization of adsorbed oleate at the fluorite surface. It has been found that modest changes in the adsorption density at high temperature and high oxygen potential do not provide a satisfactory explanation for the significant increase in the hydrophobic character of the system under similar conditions. Rather, FTIR spectroscopic measurements suggest that chemical interaction between adsorbed oleyl groups occurs at high temperature and/or oxygen potential and accounts for the increased hydrophobicity. Specifically, the intensity of the =CH bond of the adsorbed oleate diminishes at high temperature and/or high oxygen potential. Such a phenomenon was not observed in control tests with the calcium oleate soap. For extensive reaction at the fluorite surface, the presence of a new surface species has been identified. These results indicate that the fluorite surface catalyzes an oxidation and/or polymerization reaction between adsorbed oleyl groups which results in a more hydrophobic structure at the fluorite surface.

Jan 1, 1986

By W. J. Guay

Carbonaceous gold ores containing gold dispersed in sulfides are refractory to cyanidation because: ( 1) the carbonaceous materials adsorb gold during cyanidation; (2) a portion of the gold is so finely dispersed in the sulfide mineral lattice as to preclude contact with cyanide solution; and (3) a portion of the gold is chemically combined with carbonaceous material. Techniques which have been used to treat these ores are: (1) roasting or chemical oxidation to decompose sulfides and carbonaceous materials; (2) flotation to reject carbon; (3) the use of kerosene or other reagents to passivate the adsorptive carbon compounds; (4) carbon or resin in pulp; (5) flotation of a bulk concentrate which is treated by one of the above methods; and (6) the use of chelating agents which have a stronger affinity for gold than the activated carbon in the ore.

Jan 1, 1981

By Lloyd R. Nelson

The feasibility of producing low carbon (LC) ferromanganese (FeMn) by lime-'ore' melt refining of high-grade ferromanganese silicon (FeMnSi) was investigated. Thermodynamic simulations demonstrated significant benefits in moving from a single-stage ladle operation to a two-stage counter-current reladling operation (to emulate the commercial Penin Process). The theoretical alloy silicon content was predicted to be refined from 1.57 to 0.005 per cent silicon, at a 6.2 per cent higher manganese yield (yield predicted to increase from 82.3 to 88.5 per cent). Extension of this counter-current refining principle, to a multistage Counter-Current Reaction Launder (CCRL) was investigated using the Slag Metal And Gas Klnetics (SMAK) software to model the mass transfer kinetics of the multicomponent coupled reaction system. Simulation results suggested that commercial production of 50 000 tonnes per annum (tpa) of refined LC FeMn, containing less than 0.5 per cent silicon, at manganese yields of up to 90 per cent, should be feasible in a compact CCRL (7 m long by 0.7 m wide).

Jan 1, 1994

By W. C. Meyer

Surface tension and its control are important in the concentration of ores by froth flotation, both in terms of producing the proper bubble size distribution and to render the ore surface of interest hydrophobic such that adhesion to a bubble will take place. The influence a substance has on surface tension has traditionally been measured using static, equilibrium techniques. Yet many applications such as flotation involve rate-related effects of surface tension where equilibrium values are not reached. In the time frame of 1 - 300 seconds, aging effects have been noted for bubbles formed in dodecylamine acetate solutions; a slow decrease in surface tension occurs until an equilibrium value is reached, as studied by Finch and Smith (1972). Since stationary bubbles do not exist in flotation cells because of the turbulence generated by agitation and aeration, it is more likely that the chemical composition of the bubble is determined during its formation, under dynamic conditions. The chemical composition is extremely important because the induction time required for a particle-bubble entity to collide and adhere to each other is augmented by favorable surface tension (wetting) proper- ties between the surface of the particle and the bubble air-water interface or envelope, as considered by Mackenzie and Matheson (1963). Finch and Lyman (1976) have established that the probability of a "permanent" attachment taking place during this contact time is aided by the ability of an oil droplet (viz. bubble) to relieve non- equilibrium surface tension effects which are involved in the water-thinning process. This Maragoni effect, or surface elasticity, can be considered in the context of particle agglomeration addressed by Kao and coworkers (1975). Water drainage leads to the formation of a collector-frother meniscus appearing between the colliding entities, arising from their combined partial immiscibility in the water phase and promoted by hydrophobic bonding within the interface. Together they constitute a liquid bridge whose force of attraction drawing the particles together is proportional to the interfacial tension existing between the water phase and liquid bridge. This adhesive force shows an approximate linear decrease with separation distance until rupture occurs, that is, FX = Fmax (1 ? X/Xr) (1) for a distance of separation X and rupture distance G. The greater the surface elasticity of the bubble, the greater will be the rupture distance and the better will be the force of adhesion. Since van den Tempel (1965) has related surface dilational properties of bubbles to the elasticity, E, of the film as

Jan 1, 1983

By Anupam Madhukar

The essence of an atomistic unified kinetic model of strained thin film growth and defect initiation is presented along with a comparison of its consequences obtained from computer simulations with experiments. Within the competing kinetics of a strain dependent activated incorporation of atoms and an asymmetry between upwards and downwards inter-layer migration, the model provides a consistent description of 2D versus 3D morphology evolution accompanied by the appearance of surface vacancies and steps at no energy cost. The correlated migration of these precursor defects offers an atomistic mechanism for the emergence of surface half-loops from the growth front (thus accounting for configurational and thermal entropy) governed by activation energies closer to their correlated motion under the evolving strain fields and thus substantially less than those calculated with respect to the perfect crystal as the reference state. The essential mechano-chemical nature of the problem is compared and contrasted with the historical literature of such phenomenon as precipitation hardening and sintering in metallic and ceramic composites.

Jan 1, 1994

By Dolf W. Fieldman

Most recently the geologic setting of the mineral deposits in the Silver Cliff district is described by William M. Sharp in ?Geologic Map of the Silver Cliff and Rosita Volcanic Centers, Custer County, Colorado?, (U. S. G. S. Map I- 1081). The discussion will relate only to the southern half of the Silver Cliff volcanic center and differences in geologic interpretation, which are largely structural, will be pointed out as they arise. Only the manganese/silver zone of the Kate Area will be discussed in detail.

Jan 1, 1980

By L. Bichler

Utilizing thermal analysis techniques, pioneering research into the solidification mechanism of a popular magnesium alloy AZ91E cast by the Lost Foam Casting (LFC) process was carried out, Foam characteristics, section thickness and application of vacuum were seen to have profound effect on the cooling rate, thermal gradients and casting temperature profiles.

Jan 1, 2005

By G. W. Mannard

The large massive sulphide deposits present a formidable challenge to the economic geologist. They represent such huge concentrations of iron, sulphur, base metals and precious metals that it is difficult to conceive how they were derived from the crust or mantle of the Earth. The problem of the origin of massive sulphide deposits has generated a geological controversy which has lasted two hundred years and shows no sign of abating. The economic incentive to solve this problem is great, as the massive sulphide bodies are the moat important source of the world's zinc, lead, and silver, as well as yielding large amounts of copper and gold. Using the criteria of abundance, size, age distribution and gross value of contained metals, the predominant sub-group of the massive sulphide deposits is that which comprises the crudely conformable pyritic (or pyrrhotitic) deposits which occur in stratified volcanic and sedimentary rocks or their metamorphosed equivalents. Examples of this sub-group are: the Buchans, Bathurst, Noranda, Kidd Creek, Flin Plon and Sullivan deposits of Canada; the Mt. Isa and Broken Hill orebodies of Australia; the Cyprus, Rio Tinto, Meggen and Rammelsberg deposits of Europe; Ducktown and the United Verde in United States; and the Kuroko deposits of Japan.

Jan 1, 1973

By A. Aly Selim

This report describes the feasibility of predicting percussive drilling rates by equations derived from statistical regression analysis. The least squares statistical method was used and the analysis was performed both by direct and by stepwise linear regression analysis. The predicted penetration rate is a function of the drill power and the physical properties of the rocks penetrated. The results show promise that the technique may be of value in providing a mathematical model by which percussive drill manufacturers and users can predict the performance of a given drill. Experimental work involved two mining type percussive drills. Penetration data for these drills were determined from nine rocks drilled in the laboratory. Drill work rates (power) were determined in a separate series of experiments. Rock physical properties were measured from diamond-drill core samples taken from the same blocks used for percussive drilling.

Jan 1, 1970

By Edward M. Downs

This paper is a brief review of the lubrication requirements of enclosed gearing on earth moving equipment, particularly as they apply to intermediate and large draglines and shovels used in open pit mining operations. It discusses the requirements of spur, helical and herringbone gearing in both horizontal and vertically mounted applications. The effects of base stock, oil viscosity, additive treatment, quantity of oil and method of application are considered. In addition, a newly designed circulating oil system for enclosed swing gear cases and the reasons for its development are discussed.

Jan 1, 1968

By Beatrice L. Lukens, David Schlain, John D. Prater

"The electrolytic manganese process developed by the Bureau of Mines4/ and now in use in the commercial plant of the Electromanganese Corp. at Knoxville, Tenn., and in the Bureau of Mines pilot plant5/ at Boulder City, Nev., involves the electrolysis of a solution of manganese sulfate and ammonium sulfate in a diaphragm-type cell. Metallic manganese is deposited on the cathodes, and sulfuric acid is produced at the anodes.. The spent electrolyte contains, in addition to the sulfuric acid, approximately 30 percent of the manganese and most of the ammonium sulfate originally present in the feed solution. This spent solution is used to leach fresh ore that has previously been given a reducing roast. The resulting leach liquor is purified and returned to the cell.Since the presence of small amounts of certain impurities in the electrolyte may be very detrimental to the electrodeposition of manganese, the purification of feed solution is a very important step in the process. According to the purification method6/ now in use in the Bureau of Mines pilot plant at Boulder city, Nev., cobalt, nickel, iron, arsenic, lead, copper, etc., are removed by precipitation as sulfides at a pH of 6.0 to 6.5. Residual sulfides and colloidal material are removed from the resulting solution by ferric hydroxide formed by adding a small amount of iron sulfate and passing air through the solution. Feed solution purified in this way contains less than 1/2 mg.-per liter-of such impurities as arsenic, iron, cobalt, nickel, copper, etc., and is pure enough to give consistently excellent manganese deposits.Although this purification scheme has given satisfactory results at the Boulder City pilot plant knowledge of the specific effects of various impurities would be valuable. Such information would be useful in diagnosing the causes of cell room operating difficulties, and might aid in the recognition and correction of impurity difficulties arising from the use of new ores.. The purpose of this investigation was therefore, to study the effects of various concentrations of some common impurities.Since the effects of some impurities may not be apparent during short deposition periods and since harmful impurities often cause erratic results rather than consistently poor ones, it was believed that conclusions concerning the effects of impurities should be based upon the results of a fairly large number of 20- to 24-hour tests. Because of the time required for such tests, it was necessary to limit the scope of the work to a few of the more common impurities."

May 1, 1946

By C. E. Reistle

The generation of steam for drilling operations has visually been accomplished in the past by the use of portable locomotive-type boilers without the aid of auxiliary equipment or advanced for economizing fuel or water consumption. This has been due primarily to the fact that the steam-generating plant of a drilling well must necessarily be of temporary and portable design, and the amount of steam generated has not been considered sufficient to justify the additional expense necessary to obtain more economical operation. However, with the constantly increasing depth to which oil wells are being drilled and the use of larger and heavier equipment, the steam requirements have reached a point where equipment and methods that were previously considered as applicable only to permanent plant installation can be and are being used to a decided advantage by the more progressive operators. As an example of the present-day requirements and the rapidly increasing steam consumption in rotary drilling, a comparison between the requirements during the intensive drilling period in the Seminole end Oklahoma City fields of Oklahoma is of interest. In the Seminole field. There the approximate depth of rotary drilling was 3,500 feet, the general practice was to use three 85 to 90 or 100 horsepower A. P. I. code boilers operating at a working pressure of 175 to 200 pounds per square inch. The fuel end water consumption was approximately 450 to 500 thousand cubic feet of gas and 700 to 750 barrels of water per day. In the Oklahoma City field, where the average drilling depth is approximately 6,500 feet, the general practice is to use either four 100 or 116 horsepower or three 123 horsepower A.P.I. code boilers, operating at a pressure of 250 pounds per square inch. The fuel and water consumption varies from 550 to 750 thousand cubic feet of gas and from 1,000 to 1,500 barrels of water per day.

Jan 1, 1930

By G. Bitsianes

An experimental procedure was developed for studying magnetic roasting on a accurately-controlled laboratory scale. The loss-in-weight method was used and the course of reduction could be followed under a reducing gas atmosphere containing as many as five different components. Some important variables of the operation were checked on a marginal Mesabi iron ore containing porous and dense varieties of hematite as well as pure goethite. The conditions simulated were those for the grate roasting of a coarsely-sized ore burden. Temperature was maintained at 600°C; gas composition at 4.25% CO, 4.25% H2, 17.0% CO2, 15.0% H20, and 59.5% N2,, and gas flow rate at about 1,5 lineal feet per minute. The ore charge was composed of quarter-inch cubes. Under these conditions, the ore porosity was found to be one of the governing variables of the operation. Results showed that an ore size limitation existed as a function of this ore porosity. For efficient magnetic conversion, the size limit was 3/8 inch for very porous ores and about 65 mesh for very dense ores. An anomaly was noted in the weight losses incurred during actual magnetic conversion. For goethitic ores, these were generally about 13 per cent higher than could be accounted for theoretically. The effect was attributed to possible non-stoichiometric structures forming during the reduction process.

Jan 1, 1960

By Thomas H. Heine

"The Rabbit Lake uranium deposit is located at 58° 11’00”N.. 103°42'36""W., close to the west side of Wollaston Lake, and approximately 800 km north of Saskatoon. The orebody is hosted by Aphebian Wollaston Group rocks, initially deposited as a series of shallow-water marine sediments consisting, in part, of carbonates and possible saliferous petites. Metamorphism during the Hudsonian Orogeny, peaking at about 1850 Ma, recrystallized the sediments to upper amphibolite grade paragneisses. This was accompanied by partial anatexis. The waning stages of Hudsonian orogenesis appear to be marked by minor granitic intrusive activity.The post-Hudsonian period was marked by a long interval of physical and chemical erosion, resulting in the unroofing of the Wollaston metamorphic complex. The entire region underwent extensive lateritic weathering under tropical to subtropical conditions. Carbonates were especially vulnerable and, in the Rabbit Lake area, suffered extensive solutioning with accompanying formation of collapse breccias. Old zones of weakness also underwent periodic reactivation.It was during this period that uranium was leached from the surrounding meta-sediments by oxidizing meteoric waters, and transported into the karsted and fractured rocks of the Rabbit Lake doline.Athabasca Group sediments eventually covered the deposit, their diagenesis taking place at about 200 °C and 900 bars. This allowed the partial to complete recrystallization of the initial mineralization, resulting in a minimum age of 1281 ± 11 Major ""first""-generation pitchblende. Periodic fault/fracture reactivation modified the hydrologic regime within the deposit, resulting in episodic mobilization and recrystallization of pitchblende and other uraniferous species. This is clearly shown in the open pit at the present time: uranium is being mobilized and recrystallized on damp pit walls as bayleyite and liebigite due to the modification of the hydrologic system by mining activities.The uranium mineralization occurs mainly as fracture fillings, coatings, and impregnations within breccia zones and intensely altered metasediments. Lesser mineralization is intimately associated with phyllosilicates which form the matrix of a carbonate-col/apse mega-breccia. The primary ore mineral is pitchblende, consisting of five generations, and from which a large suite of secondary uraniferous minerals have formed. On a gross scale the metal content of this deposit appears to be simple, consisting almost exclusively of U, but minor Ni, As, Cu, Se, Fe and Co are also present. The eastern limit of the mineralization is defined by a vertically-dipping microgranite dyke - breccia complex, containing high-grade uranium values. The orebody is truncated to the west and at depth by the Rabbit Lake reverse fault. Minor mineralization occurs as fracture fillings in unaltered plagioclasite in the footwall of the ore body. Precipitation of uranium from solution could have taken place by a number of processes. A mobile reductant (methane, carbon dioxide, etc.) may have been generated from graphite present in some of the host rocks of the orebody. Sulphides are also a common accessory and may have aided in the formation of a reducing environment. Phyllosilicates may have acted as adsorbants for uranium, allowing for its fixation. This metal has also been incorporated into the phyllosilicates themselves."

Jan 1, 1986

By Louis E. Reber

Jan 1, 1922

By W. M. Houston

The phosphate formations of the Pliocene epoch were deposited along the coastal shelf of the eastern seaboard. The deposition of the phosphate is thought to be somewhat contiguous along the early shoreline, and the deposit can be more or less traced over an 800 to 930 mile path from the Florida Gulf Coast, near Ft. Myers, to the Pamlico Sound of North Carolina. This is illustrated in Figure 1. Three areas of commercial importance are currently being exploited from this extensive known deposit: 1 - The so-called ?Bone valley? in Central Florida (multiple operations) 2 - Hamilton County in North Florida (Occidental Corporation operation) 3 - Beaufort County in North Carolina (Texas Gulf Sulphur operation)

Jan 1, 1966

By J. Hamilton Duffy

This is the first of, a series of papers describing dredging methods and costs in recovering sand and gravel from the beds of rivers throughout the United States and deals directly with the methods employed and costs obtained by the Ohio River Sand Co. near Louisville, Ky. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. R. Thoenen, mining engineer of the Bureau of Mines, in the collection of data and compilation of this report.

Jan 1, 1931

By Theodore Kootz

Manufacture of high-grade ferromanganese; as a rule; requires a low-phosphorus-manganese ore with 45 to 55 percent Mn, chiefly obtained in the Soviet Union, the British Dominions, and Brazil. Also, low-manganese ores have already been used for ferromanganese production, especially in North America .and Germany. During World War I, a process was developed in which a high-phosphorus ferromanganese or spiegeleisen was prepared in the blast furnace from law- or high-phosphorus manganiferous ores, then low-phosphorus manganese slag was prepared by refining under an acid slag, and this material was, worked into a low-phosphorus ferromanganese in the blast furnace.9/ Manufacture of useful manganese ores from a phosphorus-bearing spiegel with 12 to. 15 percent Mn, 4.5 percent C,, and 0.5 percent P by slagging in a refining furnace was reported by Joseph, Barrett, and Wood.10/ The spiegel was refined to 0.75 percent Mn, 3.4 percent C, and 0.45 percent P. Thereby, a slag with about 43 to 58 percent Mn and, about 10 percent Si02, was obtained. Hotter melts gave a smaller phosphorus content in the slag than cold melts. In addition, the phosphorus content of the slag varied with the manganese content of the intermediate metal.

Jan 1, 1952