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By D Beahm

Introduction The Energy Metals Corporation (EMC) holds numerous mineral properties in the northern portion of the Great Divide Basin including the JAB Property, one of several potential properties being planned for development as a satellite facility to the greater Antelope Uranium Project. A National Instrument 43-101 Technical Report has been completed for the JAB property. This report estimates total measured and indicated mineral resources on the property totaling 3,555,022 pounds U3O8 contained in 2,400,875 tons at an average grade of 0.073 % U3O8 at a .25 GT cutoff in accordance with CIM Standards on Mineral Resources and Reserves. The JAB Property is located in Sections 13, 14, 15, 16, 21, 22, and 23, Township 26 North, Range 94 West, approximately Latitude 42o 14’ North and Longitude 108o 00’ West (Figure 1, Location Map). This property consists of unpatented mining lode claims and Wyoming State mineral leases comprising approximately 2,100 acres.

Jan 1, 2007

By Z. Yu

The effect of particle size on coal dewatering has been well recognized However, there are no systematic studies on ultrafine coal dewatering. The results discussed last year revealed the effect of flocculant type and coal wettability on the filtration of ultrafine coal In this paper, the differences in dewatering between -25 µ m ultrafine and -500 µ m fine coal with addition of flocculants, surfactants and oil-emulsions in vacuum filtration are further investigated Significant differences were observed in the reduction of the cake moisture. The utilized emulsions were found to be very powerful and promising filtration aids for both ultrafine and fine fractions of hydrophobic and hydrophilic coal

Jan 1, 1995

By Floyd M. Thorman

Gypsum is the crystalline chemical compound CaS04?2H20. A close chemical relation - and frequently occurring with Gypsum ? is Anhydrite which is Cask. Gypsun has wide commercial use because relatively simple heat processing reduces it to Plaster of Paris. While Anhydrite can be converted to Gypsum and thence to Plaster of Paris, the procedure is not simple and is quite costly. Anhydrite, however does have use in the agricultural field and in the Portland Cement industry. Occurrence of Gypsum in the earth structure is usually near or at the surface. Most underground mining is at 60 to 100 feet although one mine in southwest Virginia reaches a depth of 1300 feet. Gypsum is one of our softest minerals, rating only 2.0 on the Mohs scale of hardness. Specific gravity is 2.3 to 2.4. It is soluble in water but only slightly so. Interestingly, it is more soluble in cold water than in hot. For example, one part Gypsum dissolves in 370 parts water at 106° Fahrenheit while at 212°F. the water requirement is 452 parts. Compressive strength of massive Gypsum runs about 3000 lbs. per square inch. Color ranges from grey and brownish-grey to white.

Jan 1, 1973

By Robert J. Rothwell

Underground mining of coal by longwall mining methods has not been a predominant technique in Ohio. To date, only five mines in the state utilize this method, however, the technique has sparked a certain amount of controversy. As a mining technique, longwalling was introduced into southeastern Ohio in the early 1970's but it did not attract public attention until the mines began moving into privately held surface lands. This occurred coincidentally at about the same time that the state of Ohio began to regulate the environmental impacts of underground mining. Prior to the passage of the Surface Mining Control and Reclamation Act in 1977, (SMCRA), Ohio's reclamation law, Chapter 1513 Ohio Revised Code (O.R.C. 1513) did not regulate underground coal mines. As a result of SMCRA, the Ohio Statute was amended in 1978, to include regulation of the surface effects of subsidence. The inevitable result was that existing mines were immediately subject to regulations that were not considered during the initial mine planning process. (For an excellent survey of Ohio Laws that deal with coal mine subsidence, see Zima, 1985. ) The problem faced at that time by both the coal industry and the Ohio Division of Reclamation (the agency within ODNR charged with implementing O.R.C. Ch. 1513.1, was that of attempting to superimpose permitting requirements, and design performance standards onto mines that' had been operational for a number of years.

Jan 1, 1986

By John R. Gaines

I am not a member of AIME, and this is my first annual meeting. As a lifelong member of the non-ferrous metals industry I have enjoyed listening today to speakers point with pride and view with alarm the public relations activity or lack thereof in the halls of government, as well as at the grass roots. There is much to be alarmed about, to be sure, but also some accomplish¬ments to be viewed with pride. Other speakers have given a broad overview of our industry's relations with their several publics. I will be specific about two incidents in which The Anaconda Company faced the loss of confidence of a large portion of its publics: the nationalization of our properties in Chile in 1971 and the closing of our under¬ground mines in Butte, which was announced last October. If I have a minute left over, I will speak about our concern for the loss of confidence in business institutions which has been re¬vealed in recent public opinion polls.

Jan 1, 1975

The viability of physico-chemical purification methods such as selective flocculation for separation of two components having similar chemical composition and same crystal structure but different surface properties is demonstrated. Loss of selectivity was observed in a dolomite-dolomite mixture with Polyethylene Oxide (5 million molecular weight) as the flocculant. Hetero-flocculation was minimized using a low molecular weight PEO (MW -105) as the site blocking agent (SBA). Near complete separation was achieved at pH 10.5 at 100% recovery level.

Jan 1, 1993

It is widely accepted that particles stabilize flotation froths and that stable froths result in improved flotation performance. Predicting the effect of particle addition on froth stability is, however, challenging. Furthermore, there is currently no technique that allows the prediction of the effect of different flotation reagents on froth stability, without carrying out froth stability experiments.

By L. Bloom

"Man-Made Parameters" refers to the importance of selecting appropriate analytical procedures to acquire useful chemical data. The correct procedures are particularly critical at the sample preparation stage where decisions concerning pulverizing equipment, sample size, contamination and dissolution will impact on the final results independent of the instrumental method of analysis. Several experiments were designed to quantify the impact of these approaches.

Jan 1, 1993

By Robert M. Valentine, Randall L. Lentell

Interpretive geotechnical investigations were performed for the construction of approximately 15,250 m (50,000 ft) of wastewater interceptor tunnels in Austin, Texas. Subsurface materials consist of claystone (or clay shale), siltstone, altered volcanic tuffs, chalk and limestone. Special conditions include multiple crossings of Onion Creek with cover ranging from about 1/2 to 3 m (2 to 10 ft.), and the potential for mixed-face conditions consisting of water-bearing gravels overlying clay shale or siltstone. The methods and results of the geotechnical investigations are discussed and the inferred construction conditions are compared to those encountered during tunneling. A suggested format is presented for interpretive geotechnical reports for underground construction projects.

Jan 1, 1985

By Martin Herrenknecht

After the successful breakthrough at the end of 2006 of both TBMs into the multifunctional site Faido (MFS), in the middle of 2007 the two tunnel boring machines resumed the 12 km long section between Faido and Sedrun. In the roughly a 10 month interval both approximately 465 m long tunnel boring machines were partly dismantled, pushed through the 2.5 km long MFS, rebuilt for the new larger diameter of 9.5 m and reassembled to be ready for operation. In the rebuilding phase, improvements were made to the equipment, especially as a result of experience gained from the previous 14 km long drive in the section Bodio and taking into account the latest information regarding the upcoming 14 km section Faido. Both TBM drives are currently in the rock formations of the Lucomagno gneiss, which stretch over a section of 3.5 km from the MFS Faido to the predicted Piora Syncline. This section is divided into two fold axes of the Chièra Synform, where the Lucomagno gneiss pass from a sub-horizontal into vertical bedding. The drives, with current rock overburdens exceeding 1,500 m and, as known from the excavation phase of the MFS, in part highly disturbed rock formations, are characterized by the locally intense rock squeezing conditions with large convergences in the vicinity of the driving TBM as well as backwards due to the interaction of the two drives. High expenditure for the support measures, reduced driving performances together with extensive extra work associated with deadlines and increased costs are the result. In the paper the previous experience with the TBM drives in the section Faido and the challenges still awaiting us are presented and discussed.

By Duane B. Jorgensen

The two calcium sulfate minerals, gypsum and anhydrite, occur in many parts of the world, and gypsum has long been of economic importance in the family of industrial minerals. Gypsum, the dihydrate form of calcium sulfate (CaSO, . 2H20) and anhydrite, the anhydrous form (CaSO,) are frequently found in close association, and it is seldom that a calcium sulfate deposit will consist exclusively of one mineral or the other. Although known gypsum deposits are extensive, anhydrite makes up the larger part of total calcium sulfate resources. Although it has very minor economic use, it is important to the understanding of gypsum deposits and is referred to frequently in the following discussion. Calcium sulfate is one of the principal constituents of evaporite deposits, and when pure, has the following composition: [ ] Deposits of pure gypsum or of pure anhydrite which are large enough to be considered commercial have not yet been found because of both the metastable relationship between the two minerals, and the presence of impurities such as calcium or magnesium carbonates, chlorides, other sulfate minerals, clay minerals, or silica. Most gypsum produced ranges from 80 to 95% pure and beneficiation is normally limited to selective mining or quarrying or upgrading by crushing and screening during mill processing. END USES The largest use for gypsum is based upon the unique property which calcium sulfate has of readily giving up, or taking on, water of crystallization. With the application of a moderate amount of heat in a process known as calcining, gypsum is converted to plaster of paris, the hemihydrate of calcium sulfate (CaSO4 ½ H2O), which when mixed with water will set or harden as the calcium sulfate returns to the stable dihydrate form. This semifinished product, usually called stucco, is then manufactured into a large variety of plasters, wallboard, and block for construction use, or into plasters for industrial applications. About 75% of the gypsum used in the United States is calcined for these purposes. Uses of uncalcined gypsum are principally as a retarder for portland cement, as a soil conditioner, as a mineral filler, and other minor industrial applications. About 25% of the gypsum mined in the United States goes into these markets; however, in other countries with building practices different from those in the United States and Canada, relative usage varies widely. Calcium sulfate deposits are the world's largest sulfur resources; minor quantities of gypsum and anhydrite have been used to produce sulfur or sulfur compounds. This use is accompanied by a unique site-specific set of economics because sulfur is generally available from non-gypsum sources at lower cost.

Jan 1, 1994

By S. -H. Kim

This work investigated the effect of the concentration of CO2 and lead contamination on the forest ecosystem. Changes of the plant growth, lead concentration in soil, plant, and soil microbial community caused by CO2 concentration (380 ppm and 760 ppm) and lead contamination (500 mg/kg) were measured. Plant growth was inhibited by 50% due to lead contamination. Particularly, shoot growth was inhibited more than the root. However, the root elongation was not affected by the CO2 concentration increase. The diversity of microbial population with AWCD (Average Well Color Development) and PCA (Principle Component Analysis) showed that the lead contamination has an effect com-pared to CO2 concentration. The Shannon index calculated from DGGE profiles was high in soil with Pinus densiflora, while the effect of CO2 concentration was not significant (P<0.5). The similarity of microbial community from each treatment showed that lead has an effect on plant growth and microbial community rather than the CO2 concentration.

Jan 1, 2006

By O. Alonso-Gonzalez, F. Nava-Alonso, A. Uribe-Salas, C. Jimenez-Velasco

"Most of the gold produced worldwide is still obtained by cyanidation, in spite of the difficulties encountered in the processing of some gold ores such as the dissolution of copper-bearing minerals in cyanide solutions. The leached copper forms complexes with cyanide and causes several operating problems, which have led to the development of copper removal/recovery processes, among them the industrially accepted SART process (sulfidization, acidification, recycling and thickening). Although the SART process is in use in gold production plants around the world, new challenges are appearing with the continuous varying of the mineralogy of ores (such as higher copper grades, changing the solution composition and complexity). The optimal SART operating conditions for a specific solution are not the same when the composition of the solution changes; consequently, the efficiency of this process can decrease.The present study is a thermodynamic approach, corroborated by laboratory experiments, to explain how the main variables of the process affect the efficiency of copper precipitation as cuprous sulfide (Cu2S). The variables considered were pH value, copper concentration, cyanide/copper molar ratio and sulfur/copper molar ratio, all of which werevaried within the limits encountered in typical cyanidation solutions presenting the problem of copper.It was found that the variable that most affects the efficiency of the process was the pH value, since poor or no control of it can cause cuprous sulfide redissolution. The S/Cu molar ratio is also important: raising this ratio increases copper removal, but high ratios will also cause sulfide and cyanide losses. The effect of changing the CN/Cu molar ratio was negligible between 4 and 8. For a solution containing 300 mg/L copper and 490 mg/L cyanide, copper removal as high as 98.8% can be obtained with the addition of 0.6 moles of sulfide per mole of copper at pH = 6.IntroductionThe main process for gold production is cyanidation, because it is the most economical and efficient process so far. Precious-metal leaching occurs when the ore is placed in contact with a dilute alkaline cyanide solution. The dissociation of cyanide salts provides free cyanide ions, which allow the formation of the aurocyanide complex Au(CN)2 -. This complex can be retrieved from the solution by adsorption on activated carbon or by zinc precipitation. Although the use of cyanide represents an issue to health and the environment, there are technologies for its management and treatment that can be easily applied. Furthermore, it is a low-cost process compared with other methods that are available or under development."

Jan 1, 2015

Laboratory tests were conducted in a full-scale continuous miner test gallery to evaluate resulting dust levels for changes in face airflow, spray water quantity and pressure, and mining height. The minimum and maximum values tested for each parameter were as follows: airflows between 1.42 and 6.14 m3/sec, water flows between 56.8 and 132.5 lpm, nozzles pressures between 413 and 1379 kPa, and mining heights between 1.52 and 2.74 m. Each of these parameters were evaluated for four common spray system designs. Respirable dust samples were collected in the operator&apos;s cab on the miner and in the immediate return. Second-order polynomial models were used to represent expected dust levels and multiple stepwise regression was used to identify significant control parameters for inclusion in the models. Separate models were developed for dust levels at the operator and return locations and for each individual spray system. Interaction between control parameters and curvature effects were found in most models. The analysis indicated that at the operator location, airflow and mining height had the most significant impact on respirable dust levels. In the return, airflow and water pressure were typically the most significant parameters. The models developed for each spray system design can be used by mine operators to guide application of control parameters for a variety of operating conditions and mining heights.

Jan 1, 1994

By S. S. Wang

Dialkyldithiophosphinates are a new class of flotation collectors for base metal sulfide ores. Structurally, they are quite different from the conventional collectors such as mercaptans, xanthates, thionocarbamates and dithiophosphates. Collectors Structures [Mercaptans R-SHS Xanthates R-OCS-M+ Thionocarbamates R-OCNH-R Dithiophosphates 2 R-CCNH-R&apos; Dithiophosphinates (R) 2-PS-M+ ] In the above structural formula, R and R&apos; stand for a hydrocarbon radical, and M+ is an alkali metal or ammonium cation.

Jan 1, 1982

By Sidney A. Hiscock

INTRODUCTION Lead and zinc are today rightly regarded as sister metals. Historically, however, they differ markedly with lead being known and in general use as the metal since 3000 BC in several countries which at that time might have been described as mature economies. Zinc was not isolated and recognised as an industrial metal with distinct and valuable properties until about 1700-1800 AD (although it had, of course, been utilised as a constituent of brass for some 2000 years previously). c were well established as industrial metals by the beginning of the 20th century. The present paper briefly reviews the overall growth in world consumption* and changes in the three main areas which today represent the mature economies or industrialised areas, i. e. ,Europe, the United States and Japan. Trends in overall consumption are determined by the demands for the individual uses for lead and zinc. The changes in patterns of use in the industrialised areas - individually and collectively - and reasons for the changes are also considered. LONG TERM TRENDS - 1900-1984 The World Picture Since the beginning of the 20th century the world consumption of lead (3.9 million tonnes in 1984) has grown almost fourfold and that of zinc (4.7 million tonnes in 1984) is almost eleven times greater than it was in 1900. The long-term trend has been one of continuing expansion for both. metals although the pattern has been severely disturbed at certain periods, for example in the years immediately following the two world wars and at times of marked recessions in industrialised areas. Apart from such major setbacks, new levels of consumption have been established regularly every few years. Recently, however, consumption has not really grown and with only a slow and partial recovery in world industrial activity at present, there is no indication that the peak consumptions of 4.2 million tonnes of lead, set in 1979, and 4.8 million tonnes of zinc (1973) will be exceeded in the near future. The growth in world lead and zinc consumption since 1900 is shown in Figure 1 (which includes changes in copper and aluminium for comparison). Overall growth over the period 1900-1984 has been about two percent a year for lead and about three percent for zinc (annual growth for copper has also been about three percent). Increases in tonnage consumption and growth rates by decade for lead and zinc are summarised in Table I. However, the growth rates by decade sometimes conceal very large individual annual increases and decreases. For example, in 1975 lead consumption fell by 13 percent and zinc consumption by 22 percent compared to 1974. In 1976 consumption of lead and zinc rose by 12 percent and 18 percent respectively. The years when consumption &apos;landmarks&apos; (ie one, two, three and four million tonnes) were first reached are shown on Table 2. Clearly, the pattern of shorter periods being required to attain each extra million tonnes of consumption was broken in the 1970&apos;s. The consumption of zinc overtook that of lead for the first time in 1940, and since 1946 has always been at a higher level. Trends in industrialised areas The two key industrialised areas at the beginning of the 20th century were Europe and the United States which between them accounted for some 95 percent of world lead consumption and 98 percent of zinc consumption. Figures 2 and 3 show the growth in lead and zinc consumption, and Figures 4 and 5 the percentage shares for each area since 1900. Europe has usually been the major user of lead except for some years in the 1920fs, most of the 40&apos;s and early 50&apos;s when consumption in the United States was larger. In 1900, Europe accounted for about 64 percent of world lead consumption and the United States just over 30 percent. Currently, Europe takes about 40 percent of world consumption and the

Jan 1, 1986

By N. L. Dorset, K. L. Heasley

Unfortunately, mining and mining accidents have gone hand-in-hand since man first started to extract ore from the ground. In the first published treatise on mining, De Re Metallica, Georgius Agricola (1556) stated that cold, water, dust, stagnant and foul air, roof falls, falls from ladders and demons all caused injury and death in the mines of his day. Although demons are no longer considered a cause of accidents in modern mining, the other factors remain with us still. The United States government started keeping track of fatalities with the establishment of the federal Bureau of Mines in 1910. Successor agencies, such as the U.S. Mine Safety and Health Administration (MSHA) continue to track fatalities today. Looking at the records, it can be seen that coal mine fatalities dropped from 2821 in 1910 to only 27 in 2004. The reduction in fatalities and injuries didn’t “just happen.” It took concentrated effort from the entire mining industry: miners, supervisors, safety officials, mining inspectors and mining researchers. But first, specific hazards must be identified before they can be corrected. In past, coal mining accidents have been analyzed by: type (roof fall, electrical, etc), mine attribute (location, seam height, etc.), and aspects of the mineworker (work experience, job classification, etc). Much of this research helped to direct the industry’s attention to where additional vigilance and safety training was needed. No doubt this directed effort has led, at least in part, to the decrease in coal mining fatalities. This paper takes a novel look at coal mining fatalities: it examines the risk of fatalities based on how long the mine has been open.

Jan 1, 2006

By M. W. Ryan

The US Bureau of Mines investigated cold-cutting alternatives to oxyacetylene torch cutting of metal. The alternatives examined were a pneumatic circular saw with an abrasive cutting wheel, a handheld abrasive water-jet cutting tool, an ultrathermic-cutting system, hydraulic punches and cutters, and a pneumatic reciprocating hacksaw. Sparks generated with the pneumatic circular saw or ultrathermic-cutting system were not completely eliminated with the use of water sprays. The water sprays also reduced the cutting rate of the pneumatic circular saw by 70%. The safety and performance of a handheld abrasive water jet cutting system requires additional research. The hydraulic cutters and punches are readily available and do not introduce any hazards. However, they are not comparable in price to the oxyacetylene gas torch and many different attachments would be needed to replace the torch. The pneumatic reciprocating hacksaw, which did not produce any sparks, is an acceptable alternative in terms of cutting rates. However, the price of the saw and blades is not comparable to that of the oxyacetylene gas torch. The results of this study will further the advancement of safe, efficient alternatives to oxyacetylene gas torches, which will improve miner safety.

Jan 1, 1996

By M. K. Han, K. N. Han, P. B. Queneau, W. J. Dawson

The development and scale up of hydrothermal synthesis processes for manufacture of high performance materials is discussed. Traditional hydrometallurgical processes are reviewed, leading into a discussion of process development concerns for manufacture of modern materials. Three case studies are presented, including a piezoelectric ceramic, barium titanate for multiyear capacitors, and high purity chromium metal. Factors for selection of reactor design are presented, as well as results of scale-up studies on the three products.

Jan 1, 1993

By G. A. Kordosky

The literature contains several references to the influence of copper solvent extraction reagents on crud formation, but, there is disagreement as to whether the reagent has an influence on crud generation. The results of three pilot plant campaigns, where crud generation was studied as a function of the copper solvent extraction reagent, are reported. These pilot plants were run at operating copper solvent extraction plants using the aqueous solutions being treated by the commercial copper solvent extraction plants. Two of the pilot plant studies showed that the copper solvent extraction reagent had a significant influence on the extent of crud formation while the other pilot plant study indicated the copper solvent extraction reagent had a lesser influence on crud generation.

Jan 1, 1996