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By C. Flores, L. G. Twidwell, T. S. Jordan

It is well known that manguniferous silver ores containing manganese intimate) associated with silver are not amenable to conventional extraction methods. The segregation process has been applied primarily to the recovery of copper from oxidized and oxide-sulfide ores. A new alternative process, consisting of segregation roasting followed by flotation to recover the silver from refractory manganiferous silver ores, was studied using a 23-factorial experimental design. Laboratory investigations were conducted on a manganiferous silver ore analyzing 0.02% copper, 0.09% lead, 0.33% zinc, 12.55% manganese and 187 g/t silver. The investigation was designed to study the effects of the addition of salts, coke and copper (11) oxide on silver recovery. The results indicated that 79.3% of the silver can be recovered in the absence of copper oxide and 88.4% of the silver can be recovered with a copper oxide content of 1.5% at 750°C, 2% salt (NaCI). 1 % coke and 30 min of roasting. It was concluded that the addition of copper oxide improves silver recovery.

Jan 1, 1996

[Trans. No. Place Date Vol. Page 1. Wilkes-Barre, Pa.* May, '71.. 1 3 2. Bethlehem. Pa Aug., '71.. 1 10 8. Troy, N. Y Nov., '71.. 1 1S 4. Philadelphia, PaFeb., '72.. 117 5. New York, N. Y.*May: '78.. 120 5. Pittsburgh, PaOct., '72.. 125 7. Boston, MassFeb., '78.. 128 8. Philadelphia, Pa.* May, '78.. 2 3 9. Easton, POct., '78.. 27 10. New York. N. YFeb.. '74.. 2 11]

Jan 1, 1946

By F. W. Bowdish

Analysis of data on the equilibrium exchange of sodium ions from salt solutions for calcium ions, from various fractions of an oxidized calcareous iron ore from Lorraine, France, strongly suggests that the calcium may be attached to the solid by only one of its bonds. Nearly equal values were found for the equilibrium expression from data covering concentration ranges of 1000 fold for the salt and 235 fold for the ion-exchangeable calcium. Differences indicated between the exchangeable calcium contents of the slime and the sandy portions of the ore, as well as the equilibrium relationship itself, are of importance in the flotation of the ore. During an experimental program on the flotation of oxidized calcareous iron ores from Lorraine, France, ion-exchangeable calcium was found in the ore. Because this source of calcium ions, if not controlled, could thwart all efforts at flotation, an extensive study was made of the phenomenon. The part of that study reported here was to obtain data on the equilibrium established between ore solids and solutions of sodium chloride, and to analyze the data to try to understand better the physical chemistry of the exchange. The ore contains oolites of goethite and quartz grains embedded in a matrix consisting of calcite and a brown cement believed to be the residue from oxidation of the silicate minerals found in fresh unoxidized ore. When ground, a substantial fraction of the ore becomes a fine slime in which is concentrated more than half of the alumina content of the ore. It is believed that the alumina occurs as unidentified clay minerals with which most of the ion-exchange capacity of the ore is associated. A preliminary experiment on the exchange of ions from the ore for sodium ions from solutions of NaCl showed that calcium was about ten times as abundant as magnesium in the exchange solutions. Thus calcium was the predominant ion in causing difficulties with flotation, and it was the only one for which data was obtained in this study. It is believed that the omission of magnesium ion exchange from consideration does not invalidate the results. It is possible, however, that inclusion of magnesium in the analyses and calculations or its prior elimination from the samples would have improved the consistency of the results. EXPERIMENTAL Data about the equilibrium exchange of sodium from solutions for calcium from the solids were obtained using two different samples of material. The solids

Jan 1, 1963

By R. J. Snoby, J. K. Alderman

Although once fairly common as a method of coal preparation in the United States, dry cleaning has virtually disappeared. Low-rank coals used for power generation in the western U.S. are suited for dry cleaning because water has limited availability in the American west. Surface moisture added through wet cleaning offsets energy improvement achieved from mineral matter reduction. Information will be presented on the commercial application of dry cleaning in North America, the historic development and current status of the technology, and the introduction of modern processing theory and control technology to the design of dry cleaning equipment and plants.

Jan 1, 2001

By B. J. Huls

The commissioning of a Distributed Digital Control. System for the grinding circuit at Cuajone, was completed by mid August, 1985. Development of a successful strategy, excellent operator acceptability and the visual aspects offered by the display of the central console, improved mill throughput significantly. The inherent features of a digital system enhanced the flexibility in grinding control and allowed the mills and classifiers to be operated at maximum capacity. This paper discusses in detail the strategy development, the production restrictions encountered, and evaluates the overall performance of the digital control system. 1.0 Introduction In November 1976, the Cuajone Concentrator, located on the western slope of the Andes in Southern Peru, was commissioned to treat a nominal 41,000 TPD of ore. A systematic elimination of production restrictions has resulted in a continual increase of concentrator throughput to 48,700 TPD before the grinding control was in- stalled.

Jan 1, 1986

Sphalerites from Devonian cassiterite-sulphide deposits and Pb-Zn-Ag fissure veins have similar ranges of Cd contents, but the average Cd and Fe contents could indicate a small initial difference in availability of Cd between the Zeehan-Renison Bell district and the Mt. Bischoff-Waratah district. Sphalerites from banded Pb-Zn deposits (Rosebery and Hercules) are characterized by low Cd content which is a world-wide feature of such deposits in exIrusive rocks, and may indicaIe a genetic relationship between ore deposition and vulcanism.

Jan 1, 1968

By W. Bakiewicz

The Lower Indus Basin deposits form a substantial unconfined alluvial aquifer of excellent quality. This aquifer contains basically highly saline groundwater, overlain in places by considerable amounts of freshwater whose origin can be traced to the present and historical courses of the River Indus. In the past the main source of groundwater recharge has been direct river seepage and water tables were generally deep. Since the establishment of a perennial irrigation regime however, deep percolation from the increased irrigation supplies has predominated and the water-table has risen to within a few feet of the surface. The river system itself is being progressively developed for irrigation and very shortly a situation will arise where the entire low winter flow will be utilised. Fresh groundwater will then be exploited to supplement the surface supplies, and at the same time a drainage system, mainly based on wells will be used to stabilise the water-table at safe depths. This paper discusses some of the methods used to ensure optimum-economic development of the fresh groundwater and describes the general design philosophy evolved by the authors firms for both irrigation and drainage wells, with respect to both well configuation and operation. Water quality standards are discussed in as much as they affect subsequent use of the groundwater. A few particular aspects are considered, including that of the values of the relevant aquifer constants, the construction of wells and the determination of screen losses. A major problem solved during the Lower Indus Project investigations has been the design of wells to-produce fresh water from layers overlying saline water. This solution is also discussed.

Jan 1, 1967

By John Newby, Edward Kennedy, Ulf Gwildis

Alluvial deposits of major rivers often provide relatively uniform tunneling conditions. However, these conditions pose specific challenges due to the tunneling behavior of the granular soils as flowing ground, if unsupported. This paper describes the design considerations and construction experiences gained during the Tunnel Boring Machine (TBM) drives for the Annacis Island WWTP New Outfall System in the Vancouver, B.C. metropolitan area. Meeting the design criteria for connecting two (2) deep on-land shafts with an in-river riser manifold required advancing a 5-meter-diameter slurry TBM through the Fraser Rivers sands and at a tunnel invert elevation with a baseline hydrostatic head of 3.4 bar.

Dec 1, 2022

By P. M. Dranchuk

"""PLANET EARTH seen from space appears as a fragile and limited life-supporting system in a vast emptiness. That such a view is, in fact, an accurate one is now more widely accepted than it was not long ago, before Earth's problems of over-population, overconsumption, limited resources and environmental degradation attained the limelight. The danger is that a government and public now deluged by doomsday prophecies and bemused by equally confident reiterations that technology will cure all may hesitate in coming to grips with the problem, in the hope that, given time, it will go away."" With these words, Preston Cloud begins a recent editorial, in Science(l), in which he presents a brief resume of some of the findings of the Committee on Resources and Man of the National Academy of Science-National Research Council(20.Their report, which is based on a two-year study by an extremely competent group and consists of some 250 pages of text, is even more far-reaching and sobering than the report on Energy Resources(3). It begins by quoting Sir Macfarlane Burnet as follows:""There are three imperatives: to reduce war to a minimum; to stabilize human population, and to pre-vent the progressive destruction of the earth's irreplaceable resources.(4)"

Jan 1, 1971

By R. G. Fleck, W. R. Webb

Iron ore mining in the Adirondack region of northern New York dates back to the Revolutionary War. It is recorded that Benedict Arnold in his campaigns in the Lake Champlain area during the American Revolution utilized the local ores to produce armament and cannon balls. Through the efforts of early pioneers, the iron mining industry in northern New York gained impetus so that in the 1880's mines in the area accounted for nearly one fourth of the iron ore produced in the United States. Both magnetite and red hematite ores were mined during this period. With the discovery of the Lake Superior ores, the iron ore industry in New York started to decline and remained relatively unimportant until 1938. Modern day methods of mining and beneficiating sufficiently high tonnages of low-grade ores to justify the large expenditures for plant and equipment prompted a resurgence in northern New York mining. During the past several years, the production of iron ore from the Adirondack magnetites has greatly increased, and production which amounted to .6%, of the United States total during the 1918-1928 period (Mining and Metallurgy, November 1943) has been increased to 2.85% of the total in 1948. Today, Republic Steel is mining in the Port Henry-Mineville and Lyon Mountain areas; the

Jan 4, 1950

By Juan Carlos Zevallos

Ante un escenario incierto y de gran tensión como consecuencia de la pandemia del COVID-19, el sector minero peruano ha venido desarrollando tareas sociales fundamentales y comprometiendo grandes esfuerzos en ayuda económica, operativa y logística. Las acciones descritas en este artículo demuestran que en los últimos años las empresas mineras en el Perú han dado un salto importante en la dinámica de su relación con el entorno, la comunidad y el Estado, lo que ha facilitado coordinar aportes y establecer sinergias.

Aug 30, 2020

By D. W. Frommer, M. M. Fine

Mineral dressing research showed that iron concentrates of commercial quality could be produced from the Pea Ridge deposit near Sullivan, Mo. Magnetic separation and flotation, on a laboratory scale, yielded concentrates ranging from 60.0 to 71.4 pet Fe at recoveries of 89.9 to 97.6 pct. Early in 1957 St. Joseph Lead Co. announced discovery of three new centers of iron ore deposition in east central Missouri.' The discovery resulted from exploratory drilling in the vicinity of a magnetic anomaly or high. A deep hole, drilled into the Pre-Cambrian porphyry to determine the cause of anomaly, penetrated a magnetite-rich deposit.' The magnetic surveys that revealed the anomalies were begun by the Missouri Geological Survey in 1929 and were continued into the 1930's.3 At that time an area in Crawford County known as the Bourbon magnetic high was located. A second anomaly, similar in size and intensity, was discovered about six miles to the northeast in Franklin County in the vicinity of Sullivan. This area was not studied in detail until the early 1940's. To determine the cause of the anomalies, the USBM drilled four holes at the Bourbon site in 1943-1944.4 The most productive hole penetrated four mineralized zones having a total thickness of 127.5 ft. These zones contained magnetite in rhyo-lite porphyry at depths between 1600 and 2000 ft. Additional iron ore below 2000 ft was considered a possibility at the time. Some years later, the USGS, Missouri Geological Survey, St. Joseph Lead Co., and others cooperated in sponsoring an aeromagnetic survey of the Bourbon-Sullivan area which resulted in discovery of a third high, about eight miles distant at Pea Ridge. This deposit, with an estimated reserve of 50 to 100 million tons of iron ore, is considered the main find, although other orebodies in the same general area are of definite interest.' When this discovery was announced, St. Joseph Lead also revealed plans to exploit the deposit jointly with Bethlehem Steel Co. A new corporation, Meramec Mining Co., was established, and 1962 was set as the target date for completing physical plant.2 Annual production goals of 2 million tons of beneficiated and pelletized iron ore were proposed. Preparation of the site for shaft sinking was begun in June 1957. Orebody and Character of Samples: Drilling to date has established the Pea Ridge orebody as a crescent-shaped pipe about 300 ft wide. Some drillholes were bottomed at 2800 ft in very good iron ore.6 he orebody is predominantly magnetite, although hematite and a mixture of hematite and magnetite occur in the upper areas and peripheral walls. Drillhole cores representing ore from different areas and depths of mineralization were grouped into composites for testing. These composites consisted of: 1) medium grade mixed hematite and magnetite, 2) high grade mixed hematite and magnetite, and 3) high grade magnetite. The medium grade ore came from three holes with depths of i350 to 1900 ft. The high grade mixed hematite and magnetite cores came from the 1790 to 2812-ft interval of one hole. Partial chemical analyses of the three samples, given in Table 1, reveal that all are excessively high in phosphorus and sulfur, and sample 1 is

Jan 1, 1960

By F. L. Grammer

The analyses given in Table I. were made several years ago at my request at a plant using Lake ores. They are of two furnaces, one making basic, the other Bessemer pig— they gave 6 casts each in 24 hr., also two flushes of cinder between each cast. They are offered simply for the sake of reference as, so far as I know, it is unusual to find so frequent full analyses made and none are on record. The variations in manganese-content in the first and second flushes on the basic furnace are interesting, if no more than a freak—the first flush being invariably higher in manganese. The iron-content of the two slags from an average of 12 flushes shows: Basic. Bessemer. Per Cent. Per Cent. Total iron...................................... 2.85 1.70 Combined iron................................ 0.72 0.52 Free iron....................................... 2.13 1.18 The greater iron-loss in the basic slag, while known, has never heretofore been so clearly set forth. This may modify the arrangement for handling slag; heretofore usually determined by proximity of the dumping-heap. If a nearby heap is used on contiguous territory, in the past, tilting molten-slag pots were used. If the Pittsburg flood-records for 30 years are a fair criterion the government regulations were inadequate, and molten slag was dumped in such a manner as to throttle the Monongahela at the time of the spring thaws. At Pittsburg the slag, where it is carried to a distance, is frequently granulated in pits and then removed in cars to which it is conveyed by clam-shell buckets. This practice is also quite customary where the slag is intended for the manufacture of slag cement. The production of 500 tons of cast-iron daily means about 300 tons of- slag and at 2.113 per cent. equals 6.4 tons

Jan 1, 1914

By Robinson T

The paper describes a spreadsheet system that enables selection of projects and companies that meet the user's corporate exploration and/or acquisition philosophy. A regularly maintained commercially available database has been used as the basis for this system. It provides an easily accessible efficient com- prehensive search method. The technique enables ranking by various criteria, both technical and financial, to provide groups of projects/companies that are of interest. Initially, target size parameters such as reserves, production and mine life are applied together with geological criteria such as age and deposit type; the significance of the targets in the context of the Australian gold industry is addressed.

Jan 1, 1988

By G. H. K. Schenck

Weather changes of a daily, weekly, or seasonal period affect mineral production and cause significant losses that are considered unavoidable. Private weather forecasting services are available on a contract basis that can significantly reduce the uncertainty associated with weather-induced changes in the production of and demand for minerals. This paper provides examples of current practice and reviews the opportunities that await those producers who incorporate weather services as an integral part of their operating, scheduling, and planning procedures. Private weather forecasts can be highly accurate because atmospheric trends such as conditions and movement tend to persist and are related to previous meteorological events. Commercial meteorological services are prepared to deal specifically with a mineral producer's special problems (Table 1). Tactical use of private forecasts is a major advance over the severely restricted value of public forecasts which, of necessity, are general in nature and cover a dispersed geographic territory. Private weather services provided on a consulting fee basis offer the mineral producer the opportunity for tactical and strategic response to weather conditions at an acceptable cost. This contrasts with the too-frequent current tendency to view weather as a random variable the costs of which are unknown and about which nothing can be done.

Jan 1, 1970

By Yoshio Waseda, Tetsuya Uda, Tom H. Okabe

"Halide salt has been tested as a reductant for producing titanium powder directly from TiCl4. From the results of thermodynamic investigation for several rare earth chloride systems, DyCl2 was found to be used for the reduction of TiCl4 instead of the conventional metallic reductant. When TiCl4 was fed into molten salts containing DyCl2 at 1073K, titanium powder of several ten micron meters in diameter was obtained. In contrast to the sponge titanium produced by the conventional Kroll process, the present new process using a halidothermic reduction in a reactive molten salt appears to be suitable for producing metal powder. From the thermodynamic point of view, the resultant DyCl3 can be reduced to DyCl2 by magnesium. By utilizing the multivalent halide redox couple, some possible ways of titanium powder production directly from TiCl4 by magnesiothermic reduction are shown to be feasible. This can also be applied to the development of a new continuous titanium reduction process.1 IntroductionTitanium and its alloys show attractive mechanical properties such as strength-to-weight, rigidity-to-weight ratios and excellent corrosion resistance. Nevertheless, the application of titanium alloys is limited compared to other structural materials (e.g. steels, aluminum alloys) because of its high cost of production. Currently, almost all of titanium is produced by metallothermic reduction of TiCl4 by magnesium (Kroll process)[1] in an airtight metallic reactor. This process is batch type and labor intensive. Therefore, many attempts to develop new process for producing titanium are investigated so far."

Jan 1, 2000

By V. Kamavaram

Ionic liquids are novel salts used as potential non-aqueous electrolytes for aluminum electrolysis at low temperatures. In the current research di-alkylimidazolium chloride ionic liquids such as 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) and 1-hexyl-3-methylimidazolium chloride ([HMIM]Cl) were investigated for aluminum electrolysis. Melt formed by mixing ionic liquid with AlCl3 is termed as chloroaluminate and is composed of several polymeric chloroaluminate anions. Ionic liquids are studied as electrolytes for aluminum electrowinning and electrorefining of aluminum based materials (A356, A360, & Al-MMC) at low temperatures. Mechanism of aluminum electrodeposition in these chloroaluminate ionic liquid electrolytes was investigated using electroanalytical techniques such as cyclic-voltammetry and chronoamperometry. Aluminum electrodeposition on pure copper substrate in AlCl3-[BMIM]Cl (1.5:1.0) electrolyte at 30°C melts was found to be quasi-reversible process with a charge transfer coefficient ( of 0.40. Chronoamperograms obtained at different voltages in the range (-0.1 to -1.0 V) revealed that the initial stages of aluminum deposition in AlCl3-[BMIM]Cl melts was instantaneous nucleation followed by diffusion controlled growth of three-dimensional aluminum nuclei. The diffusion coefficient of electroactive species Al2Cl7¯ in AlCl3-[BMIM]Cl melts was found to be 6.5×10-7 cm2 s-1 from Cottrell?s equation and 3.9×10-7 cm2 s-1 from the dimensionless current-time transients.

Jan 1, 2006

By Robert M. Mann

The Ag/S specific ion electrode has been evaluated for analysis of both free and total cyanide. Metal cyanide solutions were prepared from reagent grade compounds and by stoichiometric fixture of the metal with a potassium cyanide solution. Solutions containing Cu+1, Ni+2, Fe+2, Fe+3 and Zn+2 complexes were analyzed prior to and following EDTA pre treatment. This effort provides an understanding of the effect of each metal cyanide complex on the SIE analysis of free and "total" cyanide.

Jan 1, 1981

By George J. Young

DURing the spring of 1910 1 visited a number of open-pit brown-coal mines and underground workings in the vicinity of Halle, Halberstadt, Leipsic, Cologne and Bonn. The notes which I took and the observations which I made at the time have been condensed and make up the principal part of this paper. Certain supplementary information has been taken from several sources which are given in the paper. The mining of brown coal is one of the important industries of Germany. The coal varies in color from dark brown to almost black and is soft like loam. Pieces of wood and strips of bark and even parts of tree trunks are frequently encountered in the excavation although the coal for the most part consists of a pulverulent, more or less matted mass of small particles of vegetal matter. It is a product between peat and lignitic coal. An analysis, taken from Coal Resources of the World shows the approximate composition of the material: Moisture, 53.73 per cent.; ash, 4.98; fixed carbon, 18.08; volatile carbon, 23.31 per cent. Thc principal characteristic is the amount of moisture. This seldom runs less than 48 per cent. The ash is usually low and ranges from 5 to 10 per cent. The sulphur content is usually less than 0.5 per cent. The heating effect of the fuel ranges from 2,000 to 2,500 calories. The commercial deposits are confined to the Tertiary period although

Jan 1, 1916

By R. Q. Shotts

Nitric acid oxidation rate analyses of three coals, previously studied microscopically by the Bureau of Mines, revealed three components. Relative quantities agree with those found for the four components given by the Bureau and results are consistent with current ideas of coal constitution. Possible multi-component composition for bright coal and a reactivity-rank relation are suggested. THE physically dissimilar components of bituminous coals often are easily recognized mega-scopically. Under the microscope, reflected light or light transmitted through thin sections reveals the presence of the different components, even when these are intimately mixed. Optical methods for the quantitative estimation of the relative abundance of the various components, both by means of thin sections and by particle count, have been fully described.'. ' It has long been recognized that there are chemical and physical differences between the various petro-graphic components of bituminous coals, although analytical differences usually are small.:'. ' Only in the case of fusain have chemical differences been used for quantitative determination of a component. C. C. Hsiao and associates, at the Mineral Industries Experiment Station of the Pennsylvania State College, have described a method of analysis which is based upon the differences in the rate of nitric acid (8N) oxidation, fusain, and the other components of coal."," The reproducibility of their method and its applicability in checking microscopic determinations of fusain content have been supported by several independent investigations.'. " The writer has proposed the use of differences in oxidizability for the estimation of other components." "' The results of the oxidation of whole coals and of float-and-sink fractions of coals were reported. In most cases the plots of the logarithms of the percent dry, non-fusain, organic residue from oxidation, against time, revealed the presence of at least two distinct components. Both components appeared to oxidize according to a first order law, but the reaction constants for the components were distinctly different. One or more of the dull density fractions were found to contain but one component, and some of the lower rank coals oxidized in such a way as to suggest the presence of three components. A suitable way to check the identity and significance of the components delineated by oxidation would be to analyze a sample of coal both by the nitric acid oxidation procedure and by a microscopic method. The writer was wholly unfamiliar with either of the microscopic techniques commonly used, and to make such a comparison it was necessary to rely upon microscopic analyses made by someone else. It is hoped that some laboratory which is equipped to make both types of analyses will some day make them upon identical samples. During the past 20 years, four Alabama coals have been analyzed petrographically and the results published by the United States Bureau of Mines. They are: 1—Flat Top mine, Mary Lee bed; 2—Empire mine, Black Creek bed; 3—Wylam No. 8 mine, Pratt bed, all in the Warrior field; and 4—Soot Creek mine, Fairview bed, in the Coosa field."-" Of these, only the Flat Top mine is still operating. Because of the closing of these mines, it first appeared necessary to rely upon the indirect and unsatisfactory procedure of sampling the beds in other mines located as near to the closed mines as possible. Upon investigation, however, it was found that the Bureau of Mines still had, in storage, the very same samples which had been used in the published petrographic studies. The Bureau very generously furnished about 2000 g each of the Pratt, Mary Lee, and Fairview bed coals, largely lumps but with some fines. The blocks of coal, when received, still were covered by the paraffin coating which had been placed on the polished surface, in the case of the Mary Lee coal almost twenty years ago. Procedure The procedure for oxidizing the coal sample and removing the alkali-soluble humic acid has been described. In the present study, oxidation periods of 1/6, 1/3, 1/2, 3/4, 1, 2, 3, and 4 hr were used. All oxidations were made in triplicate. After the paraffin had been removed in boiling water and the coal washed carefully with cold benzene, the entire sample of approximately 2000 g, obtained from the Bureau of Mines, was crushed to pass a No. 4 sieve. About 200 g of this material was pulverized to pass

Jan 1, 1954