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Differentiation of a basaltic (?) magma occurred in an active volcanic area during the late Miocene and Pliocene, and a change in the general mode of extrusion from fissure flow for the basalt to explosion for the andesite reflects an accompanying increasing magmatic viscosity. A caldera formed after the flow phase was completed and was filled with coarse agglomerate, much of which has a fused appearance. After an erosion interval its shape was modified and it became gradually deeper as repeated explosions from growing andesitic volcanoes caused large quantities of pyroclastic material to be deposited. At the close of this phase the floor abruptly collapsed when a, large block of the underlying crust was engulfed. The incompetent pyroclastics filling the caldera steepened in dip and the ensuing fractures were filled by the rising magma as dykes and sills and a chonolith formed below the caldera at a shallow depth. The ensuing activity reveals a further stage in differentiation and biotite is an important new ferromagnesian to be observed in the new rocks.Fracturing of the surrounding basalts was most intense in the rocks forming the periphery of the caldera where steeply and flatly dipping faults resulted from increasing horizontal pressure directed towards the caldera.Further differentiation resulted in the increased crystallization of orthoclase felspar, as evidenced by the numerous intrusives of trachy andesitic composition. Magmatic freezing caused mineralizers to accumulate at the top of the chonolith. These eventually escaped and auriferous pyrites, tellurides, quartz, and calcite were deposited in the surrounding rocks.The flatly dipping fractures are the most important and can be expected at various depths in a zone about 4,000 ft wide surrounding the caldera. Latest movement along these was controlled by magmatic consolidation rather than the shape of the caldera. Some flat faults were able to remain open during mineralization and acted as a feeder for the shallower fractures, thus limiting the depths to which the steeper dipping fractures were mineralized with the possible exception of one particular Nw.-striking lode (the Crown-Crescent).INTRODUCTIONThe gold deposits of the Tavua district were discovered in 1932 and from 1935 to June, 1961, 1,985,041 fine ounces of gold were produced from 4,202,504 tons of ore. Of the original three producers, only the Emperor remains active in the...

Jan 1, 1962

By E. Maré

Some of the members will probably ask themselves what close relationship exists between hydro-metallurgy and a wet scrubber, but we are sure that as soon as deeper thought is given to the matter it will be realised how vital scrubbing, operations are in metallurgical plants. In ordinary metallurgical installations or pyro-metallurgical processes ore concentrates are first of all shifted from place to place and dust is created. In other cases the ores or concentrates are crushed or dried or roasted, and in each one of these operations dust and fumes, are created. All suspended particles and fumes originating from the abovementioned conditions not only, in many instances, provide health hazards which disrupt production and endanger the personnel in the plant, but also are the source of economic losses through extra maintenance and wear to moving machinery due to abrasion and corrosion. Further losses are incurred by the waste of fine, very often valuable, components. The Party who once said that in several metallurgical plants the bulk of the profits was discharged into the atmosphere by the stack wasn't stretching the truth. There is a place in Africa where a gold producing concern used to lose over 5 oz. of fine gold per day out of a total production of 3000 oz. per month. In another instance, copper concentrate going as high as 80% Cu was discharged into the atmosphere at the rate of 4 tons per day. Realising the value of removing and collecting solids and fumes created in metallurgical plants, a thorough study was made of the available plant and equipment offered on the market. Some units were found very efficient, but very expensive; some others also very efficient but with temperature and maintenance limitations. Some others were also efficient but prohibitive from the point of running costs.

Jan 1, 1963

By G. Stephan Derrickson

Any type of agitation within a confined vessel is primarily concerned with two parameters: 1) A level of agitation describing the homogeneity of the constituents (whether it be suspension or mixing) and, 2) the energy efficiency with which this level of agitation is accomplished. The following is an attempt to present a solution to the problem of adequately defining and optimizing these properties. First included is a discussion of the application of good design practices to the determination of a mechanically efficient shape to the blade elements of the propeller. These practices, excluding several appropriate modifications, have been known, but not well understood, in aircraft fluid mechanics for a number of years. Secondly, having optimized the direct impartation of energy to the medium being agitated, attention is turned to one of the more perplexing phenomena of multi-phase systems - definition and prediction of agitation levels. The result of recent study and testing is a method of scaling which the authors feel provides a lucid understanding of governing physical parameters within the agitator itself, allowing one to scale up and down with confidence.

Jan 1, 1982

By G Ryan, Yu Nazimova

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. This paper aims to highlight the global exploration opportunities that exist in connection with Ural-Alaskan (UA)-type intrusions. The key economic importance of UA intrusions is the existence of metallic platinum (mainly iron-platinum alloys) associated generally with chromite mineralisation and located within a dunite core, especially its coarse-grained part. Being very dense and resistant to erosion, platinum can form rich placers as the intrusion erodes. Big multimillion ounce placer platinum deposits of this type have historically been successfully mined for many years (eg Russia, Colombia and Alaska).However, large-scale exploration and mining of platinum placers currently occurs only in the Russian Far East. Outside of Russia, there is now little or no understanding of this type of deposit and its economic importance. Using successful operations in Russia as examples, it is demonstrated that there are many opportunities for similar discoveries all around the world, especially around the Pacific Rim, where such intrusions tend to be concentrated. Examples of highly prospective areas in eastern Australia and New Zealand are given. There is also excellent potential in British Columbia (BC) Canada, South-East Asia (Philippines, Indonesia, Papua New Guinea and New Caledonia) and South America (Colombia and Ecuador).CITATION:Nazimova, Y and Ryan, G, 2015. Platinum potential of the pacific rim of Ural-Alaskan-type intrusions, in Proceedings PACRIM 2015 Congress, pp 665–670 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Eugene H. Cowles

The German silver industry of the United States amounts in value to upwards of $6,000,000 or $8,000,000 annually. Several thousands of people earn a livelihood pursuing it, and the beautiful goods and articles manufactured from this time-honored and valued alloy are everywhere visible. German silver enters largely into our street signs, harness and house hardware, and all manner of table-ware, solid or plated. There is scarcely an hour in the day that German or nickel-silver is not before our eyes. The composition of this alloy is a very uncertain thing, and depends largely on the honesty of the manufacturer and the price the purchaser is willing to pay. It is composed of copper, zinc and nickel in varying proportions. The best varieties contain from 18 to 25 per cent. of nickel, and from 20 to 30 per cent. of zinc, the remainder being copper. The more expensive nickel-silver contains from 25 to 33 per cent. of nickel, and from 75 to 66 per cent. of copper. The nickel is used as a whitening element; it also strengthens the alloy and renders it harder and more non-corrodible than the brass made without it, of copper and zinc. Moreover, it reduces the odor emanating from brass, which is so disagreeable if it occurs about the dining-table. Of all troublesome alloys to handle in the foundry or rollingmill, German silver is the worst. It is unmanageable and refractory at every step in its transition from the crude elements into rods, sheets or wire. As a white-headed furnace-man recently said to the writer, in one of our large mills, " you can put eight crucibles into the fire, each containing exactly the same mixture of German silver, and when you take them out and pour them into slabs for rolling, seven will be a mass of scum or slag, or the stuff will swell up like rising bread and overflow the moulds, and be so full of blow-holes that it will look like a sponge. The eighth crucible will contain perfectly good metal. On remelting the next day, the bad stuff will, in nine chances out of ten, come out just as good metal as the eighth pot the day before, and under apparently the same conditions." With nickel at seventy or eighty cents per pound, German silver

Jan 1, 1890

By Tracy Morris, Weldon Read, Luis Navarro

"Bismuth is a recognized contaminant in the electrolytic refining of copper that can render many cathodes to be outside ASTM standards and unsuitable for copper rod and other downstream products if not carefully controlled. This paper portrays the performance of Molecular Recognition Technology (MRT) for bismuth removal at the Amarillo Copper Refinery (ACR) and describes how the highly selectivity gel has been successfully used to achieve good bismuth removal and how many pit falls and draw backs have been overcome.IntroductionASARCO operates one of the largest copper refineries in the world at Amarillo, Texas. The main feed for this refinery is produced at the Hayden smelter in Arizona. During the operation of this smelter a variety of metals are carried as impurities in the copper anodes because of the diversity of concentrates and residue products used as raw materials in the smelter feed mix. Even though the impurities are concentrated enough to be detected at the smelter, it is difficult to remove them completely. A simple way to control impurities at the smelter is to minimize the addition of material with a high concentration of impurities to the charge in order to reduce the output of this metal species. All this leads us to have a ""refinery problem"" [1,2,3]."

Jan 1, 2012

By Thomas N. Walthier

Ocean miners seem prepared to commit upwards of $50 million, spread over the next 10 years, to develop a deep ocean capability. More and more large companies, Kennecott, Inco and Tenneco, to name a few, singly or through consortia, are spending money, often big money, to obtain a viable and profitable marine mining industry. Much of the current involvement of the mining industry in the oceans is concerned with either exploration for or engineering studies of manganese nodule deposits and most of it is considered highly proprietary. Thus, the scope of the total effort can only be surmised. The following provide a good indication as to the magnitude of the over-all effort: (1) Hughes Tool Co., Oil Tool Division, announced last March it has been performing engineering studies and ocean surveys (in collaboration with Global Marine, a subsidiary of Tenneco Oil) for the purpose of developing deep ocean mining equipment and techniques. As a result of these studies, Global Marine will build a 35,000-ton prototype deep sea mining ship for Hughes. (2) Deepsea Ventures, Inc. has been "assiduously compiling data on the location. depth, and composi-

Jan 1, 1971

The notes from which this paper has been prepared were set down at the time of the author's departure from Australia in 1935. Mr. Frank Forman, Government Geologist of Western Australia, who has very kindly read the paper in manuscript, affirms that the views here set forth are now accepted by most geologists. Thus, Forman's recent presidential address before the Royal Society of Western Australia (1937) mentions sediments in the Kalgoorlie Series "including banded jaspers and jaspilites."While it may, therefore, be superfluous to belabour the question further at this time, Mr. Forman has encouraged the author to publish this paper as a summary or both past and present views.To those specially interested in the subject of the paper, a study of pertinent Plates attached to Western Australian Geological Survey Bulletin No. 71, 1917, is suggested.The type of rock which is variously called "jasper bar," jaspilite, or "ferruginous quartzite" is familiar to all mining men who have worked in the West Australian goldfields.In its typical form it is a "striped" rock consisting of alternate layers of white or pinkish silica with red to brown bands of iron-bearing silica.In the course of geological work in many parts of Western Australia I studied exposures of jasper bar and was repeatedly impressed with the similarity of much of the material to the sedimentary "banded iron formation" of Canada. It was, therefore, a surprise to learn that the jasper bars were not generally regarded in Australia as sedimentary horizons. It is true that Honman offered convincing evidence of the sedimentary origin of the jaspers...

Jan 1, 1939

By Robert L. Hautala

In 1978, Congress established a series of mineral institutes for a limited time to assist financially in mineral industry education and research. Later, education and research were separated, establishing generic institutes for specialized research that transferred the former research budget from the base mineral institutes program. One of the generic institutes is the Mine Systems Design and Ground Control (MSDGC). It provides for research funding specifically for mining. Other parallel generic institutes were established in pyrometallurgy, comminution, waste management, etc. MSDGC was established at Virginia Polytechnic Institute and State University(VPI). The founding group included the University of Alabama, University of Kentucky, University of Nevada Reno, University of Idaho and University of Alaska reporting through VPI to the US Bureau of Mines (USBM) and Congress. Other universities also participated on an ad hoc basis.

Jan 1, 1996

By G. E. S. Lima, J. V. B. Lemes, F. G. D. Machado, S. Monteiro, L. G. Pedroti, L. A. F. Fioresi, W. E. H. Fernandes, R. C. S. S. Alvarenga

With advances in industrial processes, new products have emerged and become essential in everyday life. These activities generate different types of wastes, which can be harmful tothe environmentif not properly disposed. Having this problem in sight and considering the importance of concrete in the construction industry, this study analyzes the behavio of Reactive Powder Concrete (RPC) with addition of granite processing waste. Scanning Electron Microscopic (SEM) tests, compressive strength and Young’s modulus tests after 1, 3, 7 and 28 days of production and shear and flexural strength after 28 days of production were performed during the analysis. The results indicated that incorporation of this residue into RPC does not affect its performance. RPC was still able to present high compressive and flexural strength.

Mar 1, 2017

By A. J. Barry

Recent developments in mechanizing longwall it mining in Europe have aroused considerable interest among American coal-mine operators because this method provides an opportunity to improve safety, production, efficiency, and recovery. The success of longwall mining in Europe has depended to a large degree on development of effective roof-control systems. One of the major contributing factors in designing these systems is development off improved supports, which combine high load-bearing capacities with controlled yield characteristics, to use in the face areas. Other factors that relate to successful longwall mining involve knowledge of the structural properties of the strata above end below the coal bed being mined, movements of these strata induced by mining, and effects of the strata movements on the strata itself, as well as on the support system used. Extensive studies of the above factors relating to long-wall mining have been made in coal-mining countries abroad, and corresponding studies (1, 2, 3, 4, 5)3/ of room-and-pillar operations have been made in this country. Although descriptions and results of experiments of mechanized longwall operations in the United States have been published (6, 7, 8), this is the first instrumented study of roof behavior on a longwall operation. In view of the possible widespread application of this method of mining to American coal mines, where underground mining conditions are different from those found in European mines, an investigation was conducted at a mechanized longwall operation inn the Lancashire No. 15 mine, Barnes & Tucker Co., Cambric County, Bakerton, Pa., to study the factors that affect roof control. This report describes this investigation and discusses the results. ACKNOWLEDGMENTS This investigation was made under a cooperative agreement between the Bureau of Mines and the Barnes & Tucker Co., Barnesboro, Pa., end was conducted in the Lancashire No. 15 mine located at Bakerton, Cambria County, Pa. The authors acknowledge the cooperation given by Richard Z. Todhunter, Sr., president, Richard T. Todhunter, Jr., general manager, and other mine officials and employees of the Barnes & Tucker Co. Mr. Edward Thomas, chief, Roof Control Section, Bureau of Mines, Washington, D. C., and Dr. Leonard Obert, chief, Applied Physics Branch. College Park, Md., collaborated in the planning and promulgation of the program investigation.

Jan 1, 1954

By Donald D. Carr

Four counties in Indiana--LaPorte, Vigo, Vanderburgh, and Switzerland--have potential for deep underground limestone mining because they are in or are near high population areas and have no surface-minable limestone de- posits. The principal markets are Gary-South Bend, Terre Haute, Evansville, and Cincinnati. Minable seams suitable for aggregate are 120 to 150 meters (400 to 500 feet) below the surface in LaPorte and Vigo Counties, about 90 meters (300 feet) below the surface in Switzerland County, and about 600 meters (2,000 feet) below the surface in Vanderburgh County. Some deposits are also suitable for high-purity uses or for cement raw materials, which enhances their potential for exploitation.

Jan 1, 1980

By Shailin Lalloo, Allan B. Nesbitt

"Gravity separation by centrifugal equipment, particularly in the mineral processing industry is a novel approach of optimising product recovery. The manufacture and sale of centrifugal equipment by recently established companies is now beginning to have a significant impact on the industry. Some benefits of operating at increased gravity include: reduced environmental issues, a shorter lead time, lower capital cost and improved recoveries of elemental mineral before entering the grinding circuit.Of topical discussion is the use of centrifugal separators for the recovery of less valuable minerals that will form a greater proportion of the feed compared to traditional scalping circuits where the gold content is extremely low. This ultimately results in the centrifugal system having to have a greater mass pull. In addition, the relative density difference between gangue and valuable mineral is likely to be less and therefore modelling and optimisation of this separation process will be necessary. Some researchers have muted using fluidisation models to model the forces present in the separation zone of a centrifugal separator2. It is not unusual for the manufactures of centrifugal separation equipment to use fluidisation terminology to describe what happens in the separation zone. Most fluidisation models are based on the empirical/classic relationship between superficial fluid velocity and voidage postulated by Richardson and Zaki. However, no researcher has proved the effectiveness of this relationship in an increased gravity Environment."

Jan 1, 2003

By Peter Amelunxen, Javier del Río, Marcial Medina

Este documento técnico describe las iniciativas de mejora y nuevas tecnologías implementadas en la planta concentradora de la mina Constancia, que permitieron incrementar en forma sostenida los principales indicadores de producción: troughput, recuperación, disponibilidad y utilización. Constancia es un yacimiento de pórfidos de cobre-molibdeno que incluye mineralización tipo skarn, ubicado a 4,100 msnm en los Andes sur-este del Perú, región Cusco.

Jul 30, 2020

By A. E. Back, S. F. Ravitz

When manganese ores are leached with sulphur dioxide, a large part of any zinc in the ore usually is extracted with the manganese.1 In the dithionate process,2,3 in which the manganese ore is leached with dilute sulphur dioxide gas and the manganese is subsequently precipitated by adding lime to the pregnant solution, the zinc is precipitated with the manganese. These facts suggested the possibility of applying the dithionate process to the recovery of zinc from oxidized ores or calcined sulphide concentrates. Accordingly, an investigation was begun, and preliminary tests were made on several ores and concentrates. The results were encouraging, but the need to devote available funds and personnel to other projects made it necessary to drop the work before the various factors involved in the process could be studied in detail. A brief mention of the process,4 however, elicited a number of inquiries, so that it appeared desirable to report the results of the preliminary work. The dithionate process as applied to zinc may be summarized briefly as follows: The ore or calcined concentrate is leached with dilute SO2 gas to dissolve the zinc, largely as zinc sulphate, in accordance with the following equation in which [ZnO] represents the "oxide zinc" in the ore or calcine: [ZnO] + SO2(g) + 1/2 O2 = Zn++SO4— [1] If, in the leaching step, the ore or calcine is suspended in calcium dithionate solution, the sulphate ion, as it is formed, is precipitated immediately as calcium sulphate, which is subsequently filtered off with the insoluble ore residue: Zn++SO4— + Ca++S2O6— = CaSO4(s) + Zn++S2O6- [2] An alternative procedure is to suspend the ore in water, filter off the insoluble ore residue after leaching, add calcium dithionate to the resulting zinc sulphate solution, and then filter off the calcium sulphate precipitate. In either event the zinc is obtained in the form of a pregnant solution of zinc dithionate, from which it can be precipitated as relatively pure zinc hydroxide by adding milk of lime: Zn++S2O6— + Ca(OH), = Zn(OH)2(s) + Ca++S2O6- [3] The zinc hydroxide precipitate is calcined to form the final zinc oxide product: Zn(OH)2 = ZnO(s) + H2O(g) [4] Theoretically the process is completely cyclic with respect to dithionate ion, the calcium dithionate required for reaction 2 being replaced by that formed in reaction 3. In practice, of course, small amounts of dithionate would be lost in the various filter cakes, depending on the economic washing limits. In the leaching step, however, some of the SO2 is oxidized to dithionale instead of sulphate, accord- ing to the following overall reaction: ZnO + 2SO2(g) + 1/2 O2(g) = Zn++S2O6-, [5] so that the dithionate losses are made up, at least in part. Ores and Concentrates Tested The analyses of the ores and concentrates tested are summarized in Table 1, which also includes the analyses of the calcines produced from the concentrates. The concentrates were roasted in a laboratory muffle furnace at the temperatures indicated until evolution of SO2 could no longer be detected; shallow clay dishes ordinarily were used; but calcines 2a and 2c were prepared in iron dishes, with the result that these two calcines were badly contaminated with iron scale. The "complex" concentrate, sample 1, consisted essentially of sphalerite grains containing inclusions of pyrite and other sulphide minerals too minute to be liberated by grinding within economic limits. In the " marmatitic" concentrate, sample 2, the iron was present largely as marmatite (that is, as iron sulphide in solid solution in zinc sulphide) rather than as pyrite inclusions. The zinc was present largely as the carbonate in the two "oxidized" ores, samples 3 and 4, and as the silicate in the "willemite" ore, sample 5. Leaching Tests The leaching cell was a 3-liter glass beaker placed in an electrically heated water bath manually controlled to maintain a temperature of 35°C in the leach slurry. The slurry was agitated by means of a flat paddle-type stirrer

Jan 1, 1950

By J. L. Fuller

This paper contains a brief summary of design descriptions and generally accepted designations for longwall ventilation systems. Various ventilation systems for longwalls developed using single-entry and multiple-entry systems are discussed. Design considerations specific to longwall mining are included.

Jan 1, 1989

By Sahendra Ram, Arnn Kr Singh, Dheeraj Kumar, Rajendra Singh

"Inherent existence of different rooms (openings) along the extraction line in a depillaring panel provides an easy path for the goaf to encroach the working area. Each of these openings in a mechanized depillaring (MD) operation along the extraction line is supported by the roof bolt-based breaker line support (RBBLS) to restrict the goaf encroachment. Different field studies by Council for Scientific and Industrial Research - Central Institute of Mining and Fuel Research (CSIR-CIMFR) found that the RBBLS works effectively during the depillaring under the shadow of stable surrounding ribs/fenders only. It is observed that, generally, these natural supports experience high value of induced stresses after a large amount of void creation inside the goaf. The induced stress creates spalling/loosening of the sides of the natural supports. Field studies also found that the positions of the RBBLS at the goaf edge need to be adjusted according to the depth of this spalling/ loosening. However, a systematic study in field for the correct positioning of the breaker line as per the spalling/loosening under different site conditions is difficult. Therefore, on the basis of the data and guidance provided by these field investigations, a detailed parametric investigation was conducted in the laboratory on simulated models for an effective design of RBBLS in a MD panel. FLAC3D is used for the simulation of the depillaring, and the available empirical formulations for Indian coalfields are used for subsequent calibration. An analysis of stress redistribution for different stages of the MD in simulated models showed the significance of the nature of overlying strata/induced stress for the RBBLS design. Discussing some results of field studies, this paper presents results of the laboratory investigations for an effective design of the RBBLS.INTRODUCTIONContinuous Miner (CM)-based mechanized depillaring (MD) is an important issue for Indian coalfields, where huge amounts of coal are locked up in standing pillars (Dixit and Mishra, 2010). Considerable variations in site conditions of these developed pillars bring a number of technical challenges into consideration during their final extraction. One of these challenges is goaf encroachment/overriding during caving of the competent roof strata. Goaf encroachment/overriding can effectively be controlled, mainly, by suitable design of natural supports (rib/snook/fender). However, there is a requirement of applied supports against the immediate roof as a considerable portion of this roof is exposed due to the presence of different openings along the line of extraction. These applied supports act as a fulcrum at the goaf edge between the working area and the goaf to facilitate the break out of the hanging roof inside the goaf. This is called breaker line support. An effective breaker line support is important for the efficiency of a depillaring operation. Generally, MD adopts roof bolt-based breaker line support (RBBLS) at the goaf edge (Singh, et al., 2014). For the first time in India, roof bolts were applied at the goaf edge as RBBLS in a CM-based MD (Leeming, 2003). In the beginning, three rows of roof bolts were installed as primary and secondary breaker lines support. On the basis of the observations of instrumented bolts, only two rows of roof bolts were used as secondary RBBLS (Ram, et al., 2014). Now, most of the MD operations in India are using only two rows of bolts as RBBLS (Table 1). However, the strata mechanics studies at different MD operations showed interesting characteristics resulting from this support (Ram, et al., 2015)."

Jan 1, 2016

By K. K. Kelley, W. W. Weller

This report contains experimentally determined heat capacity data for four crystalline sulfides -- AsS , GeS , NiS , and Ni3 S₂ -- over the temperature range from 50 ° to 298.15 ° K. The heat capacity data were used to evaluate the entropies of the sulfides at 298.15 ° K. Entropies of formation from the metals and rhombic sulfur and from the metals and diatomic sulfur gas are also included .

Jan 1, 1964

By A. Deepatana

Bioleaching of nickel laterite ores is based on the use of heterotrophic fungi organisms and their metabolites (organic acids) to dissolve nickel and cobalt from oxide minerals to form metal-organic complexes. Metal recovery from this process using an aminophosphonic acid based chelating resin (Purolite S950) was investigated as a function of metal concentrations, complexing agent including citric, dL-malic and lactic acids. Batch adsorptions were conducted using synthetic leachate solutions of nickel and cobalt with concentrations from 15 to 2000 mg/L prepared in 0.01 and 0.1 M organic acids. Adsorption equilibrium data were interpreted using the Langmuir, Freundlich and Dubinin-Kagner-Radushkevich (DKR) models. The results showed that equilibrium adsorption data for nickel-organic complexes followed the Freundlich model and those for cobalt agreed with the Langmuir model. It was observed that the maximum adsorption capacities of nickel and cobalt were 3.26 and 10.48 mg/g resins respectively. These were achieved in metal complexes prepared from 0.01 M lactic acid. Metal elution was conducted using 2 M nitric acid. High metal recoveries were achieved from low metal concentrations but were found to decrease with increasing metal concentration. The results suggest that effective recovery of nickel and cobalt from low concentration of metals, such as those generated from bioleaching operations, can be achieved suitably using chelating resins.

Jan 1, 2006

By L. Ross Weber

Gentlemen and guests of the Rocky Mountain Coal Mining Institute: This is the thirty-second regular meeting of our Institute, and rather than try to make some extemporaneous remarks, I thought it best to write them out, so I could in that way give them to you, and probably give you a new thought for the future conduct of our Institute. The thirty-first regular meeting of the Rocky Mountain Coal Mining Institute was held in Salt Lake City, June 22, 23, and 24, 1932, and due to rapidly changing conditions in the coal industry, subsequent meetings have been postponed from time to time, as many of our members and our Secretary have been tied up with code and labor matters. Since our last meeting, at which was discussed problems of vital interest to all of us, especially the production and marketing of coal safely and economically, and the stabilization of our industry, which has already suffered two years of deplorable conditions, almost two more years have been added to the record, but during the past six months miracles have happened, and an industry which formerly was unable to govern itself, has now, through the aid of our Government, at least learned how to make a proper start in that direction. Whether we like it or not, and whether or not the things being done are in agreement with our various political beliefs, without doubt, we are in a much better position today than prior to this transformation. However, it is a pleasure to all of us to note that safety has not been lost sight of in the interim, and without doubt, as later papers and statistics will substantiate, the period since our last regular meeting has probably shown the most remarkable safety achievement of any period in recent history.

Jan 1, 1934