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By H. O. Hofman

(Canal Zone Meeting, November, 1910.) I. INTRODUCTION. IN a previous paper,1 The Behavior of Calcium Sulphate at Elevated Temperatures with Some Fluxes, we published the results of our investigation, into the behavior of calcium sul-phate in air; that, is, under oxidizing conditions. The results as a whole hold good for a neutral atmosphere, or one which has no chemical effect upon calcium sulphate. The present paper deals with the behavior of calcium sulphate under reducing conditions, the reducing-agents employed being carbon monoxide and carbon, and the changes the calcium sulphide formed undergoes when it is subjected to an oxidizing-roast. Technical literature deals very sparingly with the subject. The information furnished by the recent leading chemical manuals is general. Thus Dammer,2 Moissan,3 and Abbegg,4 quote Berthier as having reduced, in 1823, calcium sulphate with carbon, and Stammer as having done the same in 1851 with carbon monoxide; Gmelin Kraut 5 add Leplay and Laurent (1848) as third investigators. Metallurgical authorities confine their statements to the known fact of reduction by carbon. II. PREPARATION OF RAW MATERIALS. 1. Calcium Sulphate.-This salt was prepared in the same manner as described in our previous paper,6 and was found to be chemically pure. * Professor of Metallurgy, Massachusetts Institute of Technology. + Metallurgical Instructor, Imperial Technological Institute. 1 Trans, xxxix., 628 to 653 (1909). 2 Handbuch der anorganischen. Chemie, vol. ii., part 2, p. 309 (1894). 3 Traité de Chimic Minérale, 1904, vol. iii., p. 543. 4 Handbuch der anorganischen Chemie, vol. ii., part ii., p. 116 (1905). 5 Handbuch der anorganischen Chemie, vol. ii., part 2, p. 233 (1909). 6 Trans., xxxix., 630 (1909).

Nov 1, 1910

By Alicia E. Ares

316 L Stainless Steel samples were solidified directionally under conditions which produced the columnar to equiaxed transition. The position of the transition was located in each sample and the distance from the bottom of the ingot was measured. During solidification the distribution of temperatures were measured by means of thermocouples located strategically. From the measured temperatures the following parameters were derived; the local temperature gradient, the cooling rate and the velocities of the liquid and solidus fronts. Comparing the location of the transition and the values of these parameters it was found that the temperature gradient reaches negative values of as low as -13.44 "C/cm, and velocities of the fronts of around 0.1 cm/s. Also, a supercooling of 5.81°C were measured which was associated with the supercooling for the nucleation and growth of the equiaxed grains ahead of the columnar front. In addition the primary and secondary dendritic spacing was measured in both regions. The spacing was compared with the predictions from available models. The results are presented and discussed in the frame of the results obtained for other alloys

Jan 1, 2002

In order to analyze and quantify distinct environmental properties in the vicinity of sites, the Site-Specific Natural Resources Information System (SARIS) has been developed based on a Geographic Information System (GIS). SARIS is one of the fundamental databases of a collaborative research program aiming at the resource orientated analysis of metallic raw material flows with aluminum and copper serving as exemplary case studies. The spatial database incorporates all present production sites of ore extraction, refining and smelting. Environmental data for each location were derived from global digital survey data covering land cover, soils, morphology, climate, topography and population density. The main application of this database is the characterization of environmental safeguard objects, which may be affected by the activity of concern. This site-specific environmental impact assessment is used to determine the relevance of environmental issues based on the distribution pattern of sites in a global framework. The derived results are used to suggest a tailored indicator approach to measure progress and performance of industrial developments relative to the predetermined site-specific conditions.

Jan 1, 2003

By B Olsson, C Glassock

Computer simulation modelling (discrete event) has been used at Olympic Dam (OD) to model the handling of ore from the point of extraction at the stope drawpoint through to the ore stockpile on the surface. Computer simulation is a well accepted tool for modelling the behaviour of such large and complex operating systems. It is a particularly useful technique in complex operations where there are multiple interactions between the inputs and outputs of various unit operations. In this instance it can be utilised during the early stages of a project, for example, as part of the business case definition phase or the early engineering phase. A well constructed and tested simulation model provides a sound base upon which informed business decisions can be made. Furthermore, the behaviour of the model with varying inputs can help build a solid understanding of how the asset behaves when varying inputs and constraints are imposed upon it and, as a result, the major points of leverage that designers and operations personnel have to affect the real world behaviour of those assets. Better decisions can be made when the right facts can be examined, various options explored and conclusions tested. Simulation modelling is one of the tools available to make this process work.

Jan 1, 2005

By Cleo G. Rall

The value of brine analyses in the study of petroleum-engineering problems was recognized early in the history of petroleum. The Bureau of Mines before 1928 had indicated in several reports.3/ ways in which analyses might be used. Because of the confusion resulting from attempts to correlate the work of different chemists using greatly varying methods of analysis and systems of computation and expression of results, a paper presenting the methods used by the Bureau of Mines was prepared and published in 1928. This system of determining the characteristic constituents of oil-field waters and of calculating and reporting results has been widely adopted by the petroleum industry. The earliest and most obvious use of water analyses is determination of the source of water infiltrating into petroleum and natural-gas wells. For this purpose it is necessary that an analysis of the connate water of the formation from which the oil is produced be available and that an analysis of the contaminated water be made. By comparing these analyses with those of connate waters from formations higher in the structure, the formation from which the infiltrating water comes may be identified.

Jan 1, 1953

Orebodies in the Mt. Charlotte-Hannan's North area N. and E. of the town of Kalgoorlie provide a marked contrast to the pyritetelluride lodes of the Golden Mile, although both groups of orebodies appear to be fundamentally related.These highly siliceous telluride-free orebodies N. of the Golden Mile are closely related to strong oblique faulting. The Golden Mile lodes, while possessing an apparent overall relationship to the oblique faults also have a close relationship to E. dipping strike faults.INTRODUCTIONThe Mt. Charlotte-Hannan's North area lies N. and E. of the town of Kalgoorlie and is separated from the Golden Mile by the Golden Pike fault. The orebodies discussed lie in an area approximately 3 miles long by 1 mile wide (Fig. 1).The area includes the site of the original discovery of gold in the Kalgoorlie district in 1893. There have been numerous mining operations over the years, the bulk of the production coming from two orebodies, Mt. Charlotte and Hannan's North. These have provided approximately 900,000 tons of the 1,100,000 tons of ore mined in the area.Production to date from the principal orebodies in the area has been as follows.1. Hannan's North orebody, 582,000 tons of ore for 275,000 oz of gold2. Mt. Charlotte orebody, approximately 230,000 tons for 75,000 oz3. Pharlap and Golden Goose orebodies, each orebody approximately 8,000 tons for 2,700 oz4. Maritana Hill orebodies, approximately 170,000 tons for 70,000 oz...

Jan 1, 1965

By David Mast, Irwan Halim, Brian Hagan, Kaveh Talebi, Jason Edberg, Amanda Foote

On June 14, 2023 Jay Dee Contractors’ Tunnel Boring Machine (TBM) “Phoenix” holed through and completed mining the second drive of the I-75 Segment 3 Storage and Drainage Tunnel. Completion of the tunnel came only after overcoming several challenges, including a groundwater intrusion event which deposited thousands of cubic yards of wet ground material into the tunnel. This paper will discuss the events which delayed completion of the tunnel by over nine months, the risk management and construction approaches assumed by the Design-Build team during bid, several challenges faced by Design-Build teams when building stormwater resilience tunnels using traditional Department of Transportation standards, and recommendations for improving risk allocation and proposal documents for future similar Design-Build tunnel projects.

Jun 23, 2024

By John C. Machisak

INJURY data and experience, with related employment statistics, at coal mines in the United States for 1958 are presented in this publication under the following general sections: (A) General injury experience: Tables 1 to 6: Current data on number of injuries, degree of injury, frequency and severity rates, average severity, and related employment and production data by work location. (B) Selected injury experience: Tables 7 to 38: Current data on principal agencies of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines. (C) Injury experience by States: Tables 39 to 43: Current data on injuries, their causes, rates of occurrence and severity; employment and production data by work location, by States. (D) Major disasters: Table 44: Data on major disasters from 1949 to 1958. A major disaster is defined as a single accident in which, or as a result of which, five persons or more are killed instantly or die at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 45 to 49: Data on fatalities and their causes at bituminous coal, lignite, and anthracite mines from the earliest records through 1958.

Jan 1, 1961

By C. G. Williams

IN preparing this paper on Canadian mine taxation, there has been no attempt to detail the requirements of the various taxing bodies; but rather to consider the matter from the standpoint of its underlying principles and give a general idea of the methods adopted. I have added an Appendix setting forth the principal features of the various Acts, which should be used for general reference only, since new rulings alter minor details from time to time. In current legislation, many important points are left to the discretion of the Ministers and their deputies. We are, indeed, fortunate in having in Canada an able and conscientious body of permanent officials, who bring a sense of justice and courtesy to their work which is most commendable, and which has done much to simplify the working out of general problems. The production of metals may rightly be deemed a form of manufacture, but differs from the average manufacturing business in three important respects: (1) In its early stages, it is wholly speculative, since it is impossible to make any definite appraisal of value or possibilities. (2) The principal asset of any mine, i.e., the ore in the ground, is a wasting asset, and is irreplaceable. (3) Any additional burden by way of taxation cannot be passed on to the public but must be borne entirely by the producer. Having regard to the first of these differences, it is apparent that, since the risk of loss is great, the reward in case of success must be correspondingly great. This fact seems to be constantly overlooked by those who regard the all too few outstanding successes in Canadian mining history as fit prey for predatory legislation. As an illustration of the speculative nature of early mining development, let us consider the Province of Ontario-and I take this illustration simply because I am more familiar with conditions there, and not because I believe it differs greatly from any other province. From 1907 to 1933, 165,243 claims were staked and recorded, from which 43 mines were developed which paid one or more dividends. There was, of course, some duplication through re-staking; also, on some claims very little work was done, and most mines have more than one claim. But, since staking and recording cost real money and effort, each of these claims must have been considered to have had merit.

Jan 1, 1935

By W. Roggenthen, Z. J. Hladysz, G. D. Callahan, W. G. Pariseau, W. Weinig, C. Randolph-Loar, R. Popielak

A Deep Underground Science and Engineering Laboratory (DUSEL) is being planned at the site of the former Homestake Gold Mine in Lead, SD, under the sponsorship of the U.S. National Science Foundation (NSF) in cooperation with the Department of Energy (DOE). This national facility will host a variety of multidisciplinary science and engineering experiments, including physics experiments that require shielding from cosmogenic radiation. Current plans include construction of large rooms (up to 55 m in width) at depths of 1.48 km (4,850 ft) and 2.25 km (7,400 ft) below the surface. Preparation of the preliminary design required the development of a geotechnical characterization program, including preliminary drilling and coring, core logging, drill hole mapping with a televiewer, drift mapping of the geology and rock structure, in situ stress measurements, and laboratory testing of the mechanical properties of the rocks and discontinuities. Overall rock quality is very good to excellent. Site investigations included geotechnical assessments for the construction of caverns and laboratory modules. The results are favorable and reaffirm selection of the Homestake site for establishment of a Deep Underground Engineering and Science Laboratory.

Jan 1, 2011

By B. E. Davis

The Bureau of Mines conducted tests on samples of two Florida phosphate slimes t6 devise a technique to recover phosphate currently dis-carded because of its fine size. A flotation technique was devised to recover the phosphate contained in two fractions of each slime: the plus 37um fraction and the plus 20-um fraction. The technique involved conditioning the flotation feed with sodium silicate and a fatty acid-fuel oil emulsion, floating a rougher phosphate concentrate, and cleaning the concentrate in two cleaner stages with sodium silicate added to each for gangue depression. Concentrates containing 21.0 to 32.3 pct P20S were produced with recoveries of 68.1 to 84.2 pct of the P20S con-tained in the flotation feed.

Jan 1, 1987

By J. A. Abols, P. M. Grady

Recovery via gravity is one of the oldest mineral processing methods available. Unfortunately, the use of gravity techniques for gold recovery has been in decline for the past century as more effective chemical processes such as flotation and leach/CIP have been developed. Recently, with the push towards more sustainable environmental outcomes, the benefits of gravity separation have become more apparent. While gravity as a unit process is not usually capable of achieving as high a recovery as flotation or whole ore cyanidation, a combination of gravity devices alone or in conjunction with these processes can offer significant advantages to the operator. This paper reviews the range of gravity devices available, their application and the results that can be achieved by maximizing gravity through the use of a combination of gravity recovery devices. Three case studies are provided.

Jan 1, 2005

By L. A. Baker

The presence of goethite in a hematite ore has been shown to strongly affect the time of heating to the firing temperature. The investigation of spalling of single pellets and of packed beds has enabled free water and goethite spalling to be identified as separate phenomena. In addition, it has been shown that even for an 18 inch deep bed of green balls the free water and goethite drying periods can be considered separately. Based on this observation, a method of predicting production rate and hood temperature profile is presented. The method required knowledge of the ore goethite content, ore grind and the green pellet bulk density. Laboratory results were found to be in good agreement with actual plant practice and have led to improved process performance.

Jan 1, 1972

By Louis A. Panek

Using an approach based on the theory of similitude, the author develops a general equation and related concepts that provide new insights to an old problem. The load-bearing capacity (strength) of a square, rectangular, or cylindrical prism of a brittle material such as rock, coal, or concrete is expressed as the mathematical product of a size effect, a shape effect, and a function of the mechanical properties (deformability, cleat/joint spacing, and friction) of the pillar, roof and floor materials. Through an application of multivariate statistical analysis, the results of assorted tests and observations of failed pillars can be combined into a fundamental scaling equation, which provides a unified, consistent approach to the estimation of mine pillar strength. The form of the equation is sufficiently general to be able to incorporate refinements in the characterization of the basis factors, as they become available through future experimentation and analysis.

Jan 1, 1979

By Norman D. Harte, George W. Holl

The development of the most important tool used in Site Testing is reviewed briefly and the application of the information gained is described. The operation of Site Testing and pregrouting of underground excavations is dealt with in detail. Practical experiences (and pitfalls into which the inexperienced might fall) are recorded. But for the application of Site Testing and grouting of shafts, tunnels and other excavations, vast areas of the present goldfields in South Africa would remain unexploitable.

Jan 1, 1981

By M. L. Harris, J. Organiscak, S. Klima, I. E. Perera

"The National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using an untreated rock dust and a rock dust treated with an anti-caking additive. Using PDM 3600s and 3700s, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH’s Bruceton Experimental Mine (BEM) using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners’ exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device. INTRODUCTION Two factors have combined to renew concern regarding respirable dust measurements and compliance. This renewed recognition is due to two regulations that have modified operators’ rock dust schedules. First, the 80% incombustible requirement in intake entries has increased both on-section and outby-the-section rock dusting. Secondly, the recent respirable dust regulation change that has increased the number of respirable dust samples taken per sampling cycle. Previously, when only 5 samples were needed bi-monthly, rock dusting could be scheduled to not interfere with the respirable dust sampling schedule. The significant number of samples now required under new regulations combined with the need to maintain 80% total incombustible content in active mining areas require the schedules for respirable dust sampling and rock dusting to intermix. This raises concerns about the amount of rock dust that potentially is included in the sampler weight gain. Additionally, the respirable dust maximum was lowered from 2.0 mg/m3 to 1.5 mg/m3 (effective August 1, 2016) increasing concern that rock dust contamination may be an issue. Currently, the acceptable practice is to apply administrative controls such as keeping the miners upwind during rock dust application or to schedule rock dusting during a maintenance shift when the number of miners present is lower. NIOSH’s research examining the quality of rock dust has led to the development of hydrophobic rock dusts."

Jan 1, 2017

Industrial minerals enjoyed a fairly successful year in 1978, despite the sluggish economy, inflation, and environmental restrictions. A glance at US Bureau of Mines statistics shows that, in general, production of industrial minerals increased from + 1% (salt) to as much as 26% (sulfur, other than Frasch or recovered). A few industrial minerals showed a decline; fluorspar production, for example, registered a 23% decrease in 1978 from 1977 due to the closing of three domestic mines. Bromine, natural sodium sulfate, Frasch sulfur, and vermiculite also had production decreases of 2-6% in 1978.

Jan 5, 1979

By Yongjun Xian

The release of fluid inclusions has a strong potential for the unintentional activation of pyrite during flotation. The present study aims to characterize fluid inclusions in a natural pure pyrite. The results indicate that a certain amount of fluid inclusions exist in the pyrite. The fluid inclusions assume a variety of shapes, including long strips, oval shapes and irregular shapes, with sizes that range from a few microns to dozens of microns. From the EDS results of hollow positions that resulted from the fracture of the fluid inclusions on the pyrite surface, certain amounts of Al, Cr, C, O, Ag and Cu were clearly detected; these elements were not detected in FeS2 pyrite itself. The contents of the inclusions were released into solution when the sample was subjected to a grinding process. Under experimental conditions of 2 g of pyrite cleaned in 40 mL of pure deionized water under an inert atmosphere, the concentrations of Cu, Fe, Cl- and SO4 2- released from the inclusions reached concentrations of 3.29 × 10-6, 32.52 × 10-6, 51.57 × 10-6 and 75.90 × 10-6 mol/L, respectively. These values are significantly greater than those from the experimental nonoxidative and oxidative dissolution of the pyrite. The fluid inclusions of pyrite were, therefore, concluded to represent the dominant sources of Cu, Fe, Cl- and SO4 2- in the aqueous solution. The present investigation provides a new understanding of the source of the unavoidable metal ions in the pulp and may benefit understanding of the flotation theory and environmental geochemistry.

By A Fitzpatrick

An integrated and dynamic water balance and water quality model for a proposed base metal mine has been created using the GoldSimÖ software package. The model was initially developed to address the water quality of the Tailings Management Facility pond and how pond discharge would potentially affect downstream water quality. However, due to changing project objectives, the modelling has expanded over time through an iterative process to encompass the full mine site and all receiving environment water quality. The model results have been used as part of the mine planning/design process but are also intended to be used for the environmental impact assessment and permitting process. The model has been built to allow for changes to input terms to be readily made as additional data becomes available. The model results serve as a prediction of water quality and the potential project impacts to the receiving environment water quality. This paper presents the process by which data from a wide variety of sources was used to construct the model and how the model results were used to guide development of a conceptual water management plan. In addition, the role of the model in establishing proposed discharge criteria will be highlighted. The model has been delivered as a fully functional application with the intent that the end-user can be other than the modeller, the development of this aspect shall also be covered. CITATION:Fitzpatrick, A, 2012. Predictive site-wide water quality modelling as a tool for mine planning and permitting - A recent Canadian example, in Proceedings Life-of-Mine 2012 , pp 71-78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By R. L. Beatty

IN INDUSTRIAL and domestic daily life carbon monoxide is the most frequently encountered toxic gas. hazardous concentrations of carbon monoxide may be present in the vicinity of many industrial operations, such as metallurgical processes, coke ovens, and fuel- and synthesis-gas producers, and may be encountered in confined spaces, such as dwellings, garages, workshops, vehicular tunnels, and mining operations, in connection with the use of heaters, boilers, internal-combustion engines, after blasting operations, and after fires and explosions. Evaluation and control of the health and safety hazard caused by carbon monoxide depend primarily on the analytical detection of the presence of carbon monoxide and determination of its concentration in air and in various gaseous mixtures. The choice of method of analysis in any particular situation depends on such factors as required accuracy, range of concentration involved, convenience, speed of analysis required, quantity of sample available, qualitative composition of sample or atmosphere to be analyzed, and possible effects of interfering gases. Some of the methods described require only adequate understanding of operational techniques, whereas others require thorough appreciation and skill in applying the principles involved. The instruments and analytical procedures commonly used for detecting and determining carbon monoxide are described in detail, and reference is made to more specialized methods:

Jan 1, 1955