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By James S. Grichar

Interest in mergers in the nonfuel mineral industry developed when 5 were listed among the 50 highest valued mergers in the United States in 1981. This report presents a Bureau of Mines study of trends in merger activity from 1960 to 1979 and explores motives for mergers in the nonfuel mining and mineral industry. The objective was to determine precedent for or a trend toward the 1981 acceleration in merger activity and to examine certain financial motives for non fuel mineral mergers. Data indicate that the relative value of non fuel mineral mergers has grown since 1972 although the number of mergers has remained proportionate to historical trends for all mergers. Since 1974, the assets acquired in "large," nonfuel mineral firm mergers, those of $10 million or more, have comprised at least 93 pct of assets acquired. More nonfuel mineral firm mergers involved mineral companies as the acquiring firm than vice versa but mining and minerals firms acquired were of higher value than nonmining firms. A major motivation for mergers involving large mineral firms was the acquisition of assets at less than replacement costs. Univariate statistical testing, a methodology chosen for its applicability to the data, confirms this hypothesis while rejecting other financial motives. The remainder of the work is devoted to a discussion of suggested areas for future study.

Jan 1, 1984

By George Fumich

The Office of Coal Research has been supporting the development of processes for producing synthetic pipeline gas from coal since 1964. .Some of this work has also been jointly supported by the American Gas Association. The work has progressed through laboratory investigation, to bench scale, to pilot plant. It was far from a crash program, generally being fund-limited.. As of one year ago, we had reached the following position: 1. The Institute of Gas Technology HYGAS. process pilot plant in Chicago, Illinois, was in the process of being finally completed. This plant is designed to produce about 1,500,000 cubic feet of pipeline-quality gas per day from 75 tons of coal. 2. The Consolidation Coal Company, CO2 Acceptor Process pilot plant in Rapid City, South Dakota, was well._ on its way to completion. This plant, designed primarily for lignite and subbituminous coals, has about one-half the design capacity of the HYGAS plant. Additionally, the initial construction did not provide for cleanup and methanation; only the preliminary synthesis gas is produced. 3. The Bituminous Coal Research, Inca, BI-GAS pilot plant was in a preliminary design stage. A site had been selected near Homer City, Pennsylvania, to build this plant, planned to consume 120 tons of coal per day. Meanwhile, as you are all well aware, a natural gas shortage was developing in this country. Much has been published about it, so I will not. bother you with further details. Suffice it to say that the reserve-to-production ratio has been steadily declining, because we have been using.-as-faster than we have been find-

Jan 1, 1972

By E C. Holloway

"The financial valuation of mining assets has a number of fundamental differences to the valuation of many other asset groupings. One such difference is that typically, the greater proportion of both the cost and revenue sides of the cash flow are inherently governed by systemic market forces.As a result, the range of outcomes for the valuation of each mining asset is more unpredictable, with higher levels of risk and uncertainty. In contrast, the management function of many other non-mining businesses or industry groups can control at least a portion of the cash flow by maintaining the margin or controlling the sales price. The management teams of mining businesses and operations typically have limited options, and are thus price-takers for both costs and revenues. As mining is an inherently cyclical industry, large, long-life operations can exist through several price cycles, making valuation both subjective and challenging.The outcomes of both static- and stochastic-based valuations, as well as the internal probabilities of the associated cash flow statements, are significantly impacted when the correlations between the appropriate parameters are quantified, modelled and incorporated into the valuation framework. The appropriate parameters for correlation modelling primarily include those that are governed by systemic market forces. Applying this process results in a different risk profile for the asset by allowing the risks resulting from systemic market movements to be more accurately quantified and then objectively minimised. This process also reduces the level of residual uncertainty in the valuation outcome.This paper presents a valuation methodology to pragmatically incorporate this level of valuation sophistication and statistically quantify the associated increase in the level of confidence of the valuation outcomes reported.CITATION:Holloway, E C, 2016. Correlated valuation methodology, in Proceedings Project Evaluation 2016, pp 181–200 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By O. P. Hood

The spontaneous combustion of coal lies at the bottom of the subject of storage. It is useless to store coal that is to be lost by fire from spontaneous combustion. Every engineer is familiar with the phenomena of the self-heating of coal, yet, for all that, spontaneous combustion is relatively rare. If we counted the times a portion of cod was stored where it would be undisturbed for a few weeks, the number of such storage operations in any one year would mount into the millions. Of these, a relatively small number show the phenomena of spontaneous combustion and time risk per ton is very small. It is extremely rare that in the smaller operations involving; only a few tons there is any heating. There is no spontaneous combustion of anthracite, and very rarely does the domestic consumer of bituminous coal find troublesome heating. The main interest in the subject lies in the large piles needed as reserves for public-service utilities, and the industries. Everyone desires to have directions for storage that are perfectly simple and yet will insure against loss. Unfortunately, the problem is too complicated for a simple solution. Many of the factors involved are difficult to determine, as we have no practical means of quantitative measurement. The factors involve chemistry, physics, and engineering, and the man who is

Jan 1, 1939

NICOR Mineral Ventures, Inc. retained Neyer, Tiseo and Hindo, Ltd. to evaluate the potential effects of a planned dewatering operation at NICOR's proposed, 258-acre silica sand mining facility near South Rockwood, Michigan. The ?orebody? is a horizontally extensive, friable, quartz sandstone from the Sylvania Formation which also serves as an aquifer for some of the rural, residential development near the site. We conducted an aquifer test on the site which identified the important aquifer properties. Using these data and an analytical model, we determined that the radius of influence would be expected to range up to 6000 feet from the quarry during its final development stage. An inventory of water supply wells revealed that most wells had sufficient available drawdown and would not be adversely affected. A long-term groundwater monitoring program was recommended to monitor the possible effects at some of the closest wells.

Jan 1, 1987

By Kirk Ellison, Eric S. Lindquist, Peter Faust, Stephen M. McLandrich

"The 181 Fremont Tower will be an 800-foot high-rise with a 60-foot deep basement located in a dense urban part of downtown San Francisco. The design and construction methods of the subsurface elements navigated a variety of site constraints such as loose fill and soft estuarine soils, shallow groundwater, contaminants, historic obstructions, small work area, proximity of adjacent buildings, and the on-going excavation and build-out of the adjacent Transbay Transit Center (TTC) train box. Design of the approximately 260-foot-deep drilled shafts (some of the deepest foundations ever constructed in San Francisco) was proven by a full-scale load test that provided unique data on the frictional capacity of the deep soil and Franciscan Complex bedrock in the region. Design and construction of the shoring system for the 5-story basement excavation was exceptionally challenging because of the on-going construction for the TTC. To allow for flexibility during construction, hydraulic rams were placed in a transfer waler along the shared TTC shoring wall that could adjust the forces transferred through to the TTC excavation if required. Open and steady communication between the shoring engineer, the geotechnical engineer, and the shoring/foundation contractor was crucial in order to satisfy the complex constraints of this site.INTRODUCTIONThe 181 Fremont Tower is a new build mixed-use tower, currently under construction in the dense urban core of the South of Market District of San Francisco, California. This high-rise will consist of 54 above ground floors with the roof level 700 feet high. Atop the roof will be some architectural features including a spire that will top out at just over 800 feet, which will make it the second tallest building in San Francisco upon completion.The tower is being developed by Jay Paul Company and the architectural design is by Heller Manus. The structural engineer and geotechnical engineer for the project is Arup North America Ltd (Arup). The shoring designer is Brierley Associates (Brierley). The general contractor is Level 10 Construction (Level 10) and the specialty foundation contractor and excavation contractor is Malcolm Drilling Co., Inc (Malcolm)."

Jan 1, 2017

By H. 0. HOFMAN AND W. MOSTOWITSCH

I. INTRODUCTION. THE mineral gypsum, CaSO, + 2 H2O, has been used for many years as a sulphurizing and basic flux in several smelting¬operations. Thus, in smelting oxide nickel-ore in the blast furnace, it is commonly added to the charge to furnish the sulphur necessary for collecting the metal in a matte, and a base for slagging the siliceous gangue. In the concentration of lead-copper matte in the reverberatory furnace it has been used for years at Freiberg, Saxony1 for a similar purpose, and for producing at the same time a copper-matte with less than 0.15 per cent. Fe. The latest use gypsum has been put to is in the blast-roasting process of Carmichael-Bradford.2 The term "blast-roasting," given by A. S. Dwight3 to the Dwight-Lloyd method of roasting and agglomerating ,I is a happy generic term which covers the ground better than the " lime-roasting" of Ingalls' or the " pot-roasting " of Austin,6 in that it leaves the operation independent of the character of the flux and the form of apparatus, and retains the characteristic feature of this class of processes-namely, that of using forced draft. In the Carmichael-Bradford process the dehydrated material, mixed with galena-concentrate, acts as a diluent and a flux. The process differs in this from the Huntington-Heberlein7 and the Savelsberg8 processes, in both of which limestone is used.

Jan 1, 1909

By C. H. Hitchcock

History In approaching the subject of diamond-drilling practice, a brief history of the origin and development of the diamond drill may be of interest. The use of black diamonds for boring holes in rock was discovered in 1863 by Rudolph Leschot, a French engineer. In 1864, he employed a diamond bit to bore holes for blasting purposes in the construction of the Mont Cenis tunnel between France and Italy. The method was introduced and developed in the United States in the late sixties. The first deep hole was drilled for coal in 1870, near Pottsville, Penn., by M. C. Bullock. This hole was seven hundred and fifty feet deep. It can be inferred that the diamond drill was introduced into Canada in 1871, when a bore-hole, known as Harper's bore-hole, was drilled for coal at Springhill, Cumberland county, Nova Scotia; and at the old Silver Islet mine, near Port Arthur, the diamond drill was in use as early as 1872. Diamond Drills While M. C. Bullock was developing the diamond drill for exploratory work, the Sullivan Machine Company, of Claremont, N.H., was developing the diamond channelers and gadders for quarry work. These quarry machines were very successful until the high price of black diamonds became prohibitive. In 1878, Albert Ball, chief engineer of the Sullivan Machine Company, designed the Sullivan diamond drill so well known today. The first of these drills went to the Lake Superior iron ranges. After 1880, use of the diamond drill expanded rapidly and spread to all parts of the world where exploratory work was being done. In recent years, the type of diamond drill has not changed much, but better material is going into its construction. Steel castings have replaced cast-iron. Ball and roller bearings are now used instead of brasses and babbits. Gun lubrication has eliminated the oil-can. These improvements make a drill that can be operated for long periods without expense for repairs.

Jan 1, 1933

By Stephen van Duin

As productivity in coal extraction demands increase in underground coal mines, the industry is faced with finding new ways to support production without jeopardising safety. In modern mines the capacity and scale of longwall coal extraction has steadily increased to a point that support processes are failing to keep pace. In particular, roadway development is continually placed on the critical path of activities which maintain mine production, so any inefficiency in this area is quickly exposed. Original equipment manufacturers are under immense pressure to modify their machines to be more interconnected with each other, with machine communication and logistical sharing of space becoming a known requirement. This paper looks at the changing trends in mining practice, analysing available technology as well as currently emerging research into hard automation and discusses the need to integrate machinery and processes in order to see increases in productivity and safety.

Aug 1, 2013

By A. Eilers

A MARKED peculiarity of most of the smelting-works of the Far West is the looseness with which accounts of the operations are kept. Indeed, probably over half of the works do not keep any detailed accounts at all, the yearly gross statement of profit or loss being considered sufficient for all purposes. The reasons for this must apparently be sought in the as yet unsettled state of all business relations, and in the deplorable fact that only in isolated cases educated metallurgists are in charge of the smelting-works. Continual and regular assays of the ores, by-products, and slags, are almost unknown, so that it is impracticable to ascertain, even approximately, the losses in the smelting processes. Of cases where regular accounts are kept of the quantities of ore smelted, of the composition of charges, and of the fuel consumed, I know only two or three. Under these circumstances it is extremely difficult to collect figures which cover the operations for a considerable length of time, and which are so valuable for the metallurgist, who wishes to get an insight into the economy of smelting operations, as shown by practice. Figures obtained by personal observation, which can of course cover only the brief space of the visit of the travelling metallurgist, must, therefore, be made to replace the more valuable data. The writer has had occasion, during the last and the preceding summer, to visit the larger number of the Western lead-smelting works, and offers, in the following pages, such data relating to the economy of lead-smelting in the blast furnace at various works, as he has been able to obtain. The only object in doing so is to place these figures on record, so that they may be from time to time supplemented with other data, which are now wanting. I. EUREKA CONSOLIDATED COMPANY'S SMELTING-WORKS. These works smelt the ores from the mines of the same company on Ruby Hill, Eureka, Nevada. The supply is almost unlimited,

By Eli T. Conner

(Wilkes-Barre Meeting, June, 1911.) My connection, under a commission from the Councils and Board of School Control of the city of Scranton, Pa., with a recent investigation of mine-caves and the resultant damages to surface-improvements, has led to the preparation, at the invitation of our Secretary, of the present paper. It is notorious that there are, in the anthracite-fields, frequent subsidences of the surface, due to the removal of the coal beneath. No particular attention is paid to such occurrences, unless they happen to injure surface-improvements. Many caves have happened in Scranton and its vicinity, which have excited but little remark, since they have generally caused no serious damage. In August, 1909, a cave occurred in the Hyde Park section of the city, generally known as the West Side, which nearly destroyed school-house No. 16 and considerable adjacent property. 'Fortunately, there were no pupils in the building at the time; but the thought of the possible result, bad the usual number of pupils and teachers been present, aroused the public to the gravity of the situation; and the School Board employed engineers to investigate the case. Two reports were made by separate sets of engineers, which differed in some particulars. These differences were pointed out in the public press and magnified, and the consequent agitation of the subject was taken tip and greatly exaggerated by some of the metropolitan newspapers, giving to uninformed people the very erroneous impression that the whole city of Scranton was in danger of sinking into the bowels of the earth. All this tended to affect the credit of the city and to depress real-estate values. The matter was considered at a joint meeting of the Board of Trade, the Councils, and the School Board. The Hon. J. Ben. Dimmick, a former Mayor, suggested that it

Sep 1, 1911

By Verya Nasri, Jaeseoung Lee, Ashish Bhargava, Shashank Gupta

This paper presents the unique design and construction challenges for the Technoparc Station, located in downtown Montreal as a part of Réseau Express Métropolitain (REM), a light rail rapid transit system. The station is located 15 m below the street with rock-bearing secant pile wall as the primary structural system working as both the retaining and gravity structure. The paper highlights the challenges related to the support of excavation structure, invert slab resisting high hydrostatic forces, waterproofing tightness etc. It also focuses on the importance of Building Information Modeling (BIM) in underground tunneling projects for effective coordination, clash-free, optimized design and costs.

Jun 13, 2021

By Denby B, Hollands R. Schofield D

Surface mines are in operation worldwide, the vast majority employ large haul trucks for the transfer of material both to the outside world and around the site. The sheer size of these trucks and the operating conditions means there is a high

Jan 1, 1998

By AIME AIME

CERTAINLY in point of attendance, and doubtless in several other ways as well, the 147th meeting of the A.I.M.E. was the best ever held. In times of depression, mining engineers and metallurgists have plenty of time to come to the Annual Meeting but money is scarce; at the height of industrial activity they have plenty of money but no time. "The current period of transition seemed to provide ideal conditions for' both the preparation of papers and attendance at their presentation. The weather made even the Californians present envious though the weather man gets no credit, for rain and snow was what he willed. Among the elevator men, the miners have the reputation of being the toughest crowd to handle, though the best natured, withal, of all the engineering groups that meet in the Engineering Societies Building. This year Your inquiring reporter was told, "it was the damnedest meeting I ever saw; they

Jan 1, 1937

By Norman R. Paterson

In November 1980 a combined airborne electro-magnetic (INPUT.) and magnetometer survey was conducted by Questor Surveys Limited in the State Line Area, Colorado-Wyoming. The survey was the result of discussions over a prolonged period between the authors and various investigators of the State kimberlite occurrences. As a result of these discussions and literature studies, it was decided that airborne geophysical methods would be potentially useful in the exploration for new kimberlite occurrences. The survey was designed by Paterson, Grant and Watson Limited and conducted by Questor Surveys Limited over an area in which more than 15 kimberlite bodies were known and on some of which ground geophysical surveys had been conducted. The survey was designed primarily to determine the airborne electromagnetic and magnetic responses of the known occurrences and to deter- mine whether these responses would be detectable under similar conditions in other parts of the State Line District and elsewhere.

Jan 1, 1984

By S. J. Pearce

The need for a simple, very sensitive, and accurate method for the determination of benzene in blood and urine was evident throughout a recent study of chronic benzene (C6H6) poisoning conducted cooperatively by the United States Bureau of Mines, The Barrett Company, and the producers of benzene. A combustion method which will be described in a later publication, end a previously described5/ adaptation of Smyth's method were developed and used during that investigation. The adaptation of Smyth's method gave satisfactory results when dealing with exposure conditions that produced chronic poisoning in a comparatively few days, but it was time-consuming and lacked the accuracy necessary for a study of the absorption, distribution, and fate of benzene in the body during exposure to threshold concentrations of benzene vapor in air. The combustion procedure was satisfactory from the standpoint of sensitivity but was cumbersome, intricate, time-consuming, and required the use of special and somewhat expensive physical and. chemical apparatus. Following the termination of this study of chronic poisoning, possibilities for developing better methods occurred, and these have been investigated by the Bureau of Mines with the aid of Relief Works Division personnel. A microcolorimetric method for the determination of benzene in air has been described recently.6/ The present report deals with the adaptation of this new colorimetric method to the determination

Jan 1, 1936

By J. Rostami, J. Brune, S. Slouka

Respirable dust poses long-term health issues to personnel working in mining and civil projects where mechanized mining and tunneling machines are used for hard rock excavation. Machines, such as longwall shearers, roadheaders, or continuous miners, use consumable picks to cut rock. However, rock dust is generated in the work environment each time the pick tip contacts the rock surface. Additionally, the generated dust can be reintroduced into the air further down in production, such as at transfer points. The purpose of this study is to characterize respirable dust particles generated at the pick tip at two stages of pick wear: new and moderately worn. Understanding dust characteristics in terms of concentration, size distribution, and particle shape throughout the life-cycle of the pick will provide a basis to mine and tunnel operators for changing out picks to mitigate dust generation at the source. This paper discusses the dust characteristics generated from preliminary full-scale cutting tests in a laboratory of an igneous rock block cut with conical picks at new and moderately worn levels of wear. The moderately worn pick generated a size distribution that favored smaller particle sizes compared to the new pick. The moderately worn pick also generated more overall dust, as the concentration level in mg/m3 was over double the amount of the new pick. Lastly, both picks generated particles that had similar aspect ratios and roundness measures.

May 18, 2022

"Quiet, please!" is the newest directive being thrust at industry by guardians of the environment-with good reason. In countless cases, industrial noise is literally deafening its listeners, and sooner or later the volume must be turned down. Noise control is already mandatory for many companies under a Federal regulation that went on the books when the Walsh-Healey Act was revised last May 20. The new rules impose specific noise limits on any plants supplying the Government with goods under a contract valued at more than $10,000.

Jan 1, 1970

By G. Swan

"The selection of material comprising a backfill is, of economic necessity, site dependent. Nevertheless, given the existing range of typical components-coarse waste, alluvial sand, tailings a balanced or optimal choice is no straightforward matter. A new design approach toward deciding what constitutes an optimum combination of backfill material promises to be useful. In particular a 'binder ' number, based on the mean distance between aggregate particles, specific surface and cement content, is proposed. Using this number, related empirically to compressive strength, the expected mechanical performance of any cemented fill can be predicted.IntroductionOver the years a considerable volume of information has accumulated on mine backfill material design. The principal aggregate component has been deslimed mill tailings, though more recently admixtures of rock waste, sand and tailings are quite common. For these materials uniaxial compressive strength and percolation rate properties are known to be controlled by, among other things, aggregate grading. While empirical formulae exist for relating grading to percolation rates, considerable uncertainty exists concerning strength development."

Jan 1, 1985

By Gunnar Nord, Per-Anders Persson, Duri Prader

The paper gives a short resumé of the findings of the joint US - Swedish "Mechanical Boring (MB) or Drill and Blast Tunneling (DB) ? Workshop" in Stockholm December 1976. New developments and trends in both MB and DB techniques in Europe since 1976 are described, and information is given on some interesting new projects. Differences in contracting principles between the US and Europe lead to different practices for preinvestigations, design, excavation and arbitration and legal affairs. It is shown that this often leads to a higher cost in the US than in Europe for similar excavation jobs. A typical US tunnel job also has more men on the site than a similar job in Europe. This adds to the cost difference and is only partly balanced by a slightly higher rate of excavation in the US. A comparison is made between two quantitative methods of predicting MB penetration rates. These are in reasonable agreement. A probable future development in machine design is an increase in cutter load towards perhaps 25 tons per disc where the tunnel diameter is large enough to house the machine size dictated by the size of the very large electric motors required. Recent European developments in drill and blast technique include improved methods for cautious blasting, precision hydraulic drilling of small diameter holes, and non-electric interval blasting techniques. These developments still keep the drill and blast method ahead of mechanical boring costwise for tunnels in igneous rock whereas for most sedimentary materials mechanical boring has a lead, particularly for long tunnels.

Jan 1, 1979