Search Documents

By G Morgan, C Kemp

In December 2010, a trial of borehole radar technology was conducted to test the usefulness of the technique in better refining the position and geometry of narrow vein orebodies away from the primary data sources of drilling and mapping of development excavations. This paper summarises the reasons why the technique was applied, describes the testing methods selected and summarises the outcomes of the trial.Poor reconciliations of recovered metal from a section of an orebody at Jundee mine site, Western Australia, led to an investigation that identified insufficient understanding of the geometry of a narrow vein orebody as a potential cause. This orebody was situated between mapped development excavations and away from surrounding drill holes. Borehole radar was identified as a possible technique that could supply information on vein location and continuity away from other data sources allowing more accurate orebody modelling and subsequent stope optimisation.A borehole radar instrument (10 - 100 MHz frequency) was inserted into pairs of purpose-drilled boreholes on either side of relatively well-constrained mineralisation and the radar reflection data was collected. This process was repeated in five locations across the mine to represent the most common geological settings, lithologies and orebody varieties encountered at Jundee to determine the suitability of applying the technique in each of these settings. Collected, processed and interpreted radar data was compared to other geology data collected independently for verification and interpretation.Conclusions drawn from the analysis were that the technique could effectively determine the following features of the mineralised veins in the majority of test environments: geometry of veins, magnitude of offsets where structures intersect and orientations of planar structures with short strike length. The technique was very useful in selecting the appropriate structural interpretation where available data could lead to multiple, equally likely, interpretations.CITATION:Kemp, C and Morgan, G, 2012. Using borehole radar to refine orebody interpretations in a narrow vein gold deposit, in Proceedings Narrow Vein Mining 2012 , pp 121-130 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By H. E. Pawson

Giant Yellowknife is located 600 air miles north of Edmonton on the north shore of Great Slave Lake in the Northwest Territories. In its 24 years of operation some 7,730,000 tons of ore have been treated to yield $175,000,000 worth of gold.The gold ore occurs at irregular intervals throughout a fold-like sericite schist zone cutting Precambrian rocks. The ore is characterized by 40 to 80% quartz - carbonate and about 10% pyrite and arsenopyrite. Considerable amounts of stibnite and antimony sulpho-salts are also present. Gold is finely divided in the native state existing in complex association with the sulphides. In most instances stibnite is barren but minor values are evident on occasion. Visible native Fold, quite prevalent in the early operating years, is, practically non-existent today. It was readily apparent from mineral dressing investigations conducted in .1944 that Giant ore would be difficult to treat. By 1948 a flow sheet had been established and operations began. In the ensuing years, changing ore characteristics necessitated modifications to some process steps and complete abandonment of others. By 1962 the major metallurgical problems were solved and all that remained was the refining of operating performance to its highest level.With one or two exceptions today's operation follows the practice established by 1962 (Fig. 1 - Flowsheet).

Jan 1, 1973

By Qinghua Gu, BUQING XUE, XUEXIAN LI, JIANGSHAN SONG, Qian Wang

To solve the problem of time-consuming and low precision in updating the open-pit vehicle transportation network, a high precision road network model construction method for unmanned vehicles in open-pit mines is proposed. This method can be divided into two steps. In the first step, an improved deep learning image processing model named DeepLabv3 + C (DeepLabv3 + Concat) is presented. Then, the road information extracted by the DeepLabv3 + C network is used to construct a three-dimensional model of the open-pit mine road network. In the second step, aiming at the time-consuming problem of unmanned vehicle meeting in open-pit mines, a vehicle meeting strategy was proposed. This strategy is used to guide the navigation of unmanned vehicles in open-pit mines. Besides, the DeepLabv3 + C network is verified by comparing the mIOU (means Intersection Over Union), accuracy, and continuity of road image extraction with the mainstream networks. The road network model constructed in the first step is quantitatively analyzed, and its performance is compared with GPS trajectory clustering methods. At the end of the paper, vehicle running simulation is carried out on the road network model by using Unity (a 3D visualization simulation software). The results show that the road network model constructed by this method can meet the navigation requirements of unmanned vehicles in open-pit mines, and the feasibility of the vehicle meeting strategy is proved.

Jan 11, 2022

By A. D. Hahn

The Federal Bureau of Mines examined ilmenite-bearing sands in southern Texas as part of a program to discover sources of supply for the domestic titanium industry. Deposits were examined from May 1956 through January 1959 in the outcrops of sandstone beds in the Jackson group of Eocene formations in Lee, Burleson, Fayette, and Starr Counties on the Gulf Coastal Plain; in alluvial valley fill in Brewster County in southwest Texas; in the sand beaches of Matagorda Peninsula and the Galveston, Padre, and Brazos Islands--part of the offshore chain of barrier islands along the Texas coast; and in unconsolidated sediments in Willacy County on the Rio Grande delta in the southeast Texas.

Jan 1, 1961

By H. E. Peterson, W. L. Anderson

"INTRODUCTION The great demand for tungsten incident to the war has led to the exploration of a large number of low-grade tungsten deposits. To properly evaluate the low-grade deposits it is essential to have available a dependable method of analysis applicable to all types of low-grade tungsten ores. Results reported on the tungsten content of the ores have often varied quite widely and have led to confusion. The Bureau of Mines has been requested by Government lending agencies and by companies interested in the production of tungsten to publish a general method for the determination of tungsten in low-grade ores. To meet this need, the Bureau of Mines is herein submitting two methods for analysis that have been proved on a large number of tungsten-bearing ores various types in the Bureau of Mines laboratory in Salt Lake City. Also, a third method was developed that requires no cinchonine and has proved to be applicable on most tungsten ores. The cinchonine method is the generally accepted for analysis of tungsten ores. Very reliable results can be obtained by this method if certain precautions are taken, as outlined in this report."

May 1, 1943

By Rod L. Norfleet

Cemented tungsten carbides are a sintered powder - metallurgical product essential to modern industry. Because of their moderate unit price and our dependence upon foreign sources for the component raw materials, a growing recycling industry has developed in the United States. There are two basic approaches taken to recycling cemented carbides; those which leave constituting materials unaltered or direct-reuse and those which separate the constitutes back to the raw components. To separate the carbides back to their raw components usually requires expensive chemical processing and is thus confined to the lower value materials such as grinding sludges. The direct-reuse methods recycle cemented carbides back to an intermediate level, a powder capable of being recompacted and resintered into a functional end-product. The three most commonly used methods of direct-reuse recycling, the coldstream process, bloaching and the Bernard or zinc process, are reviewed,

Jan 1, 1984

By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller: Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone. Another example of the waste of large volumes of gas is in the Turner Valley field of Canada, 6 where 250,000,000 cubic feet of gas is being burned daily in flambeaus, as there is no present outlet except at prohibitive cost.

Jan 1, 1931

By D. L. Blakeman, Trimble. J. W., S. W. Banning

Noranda's Grey Eagle mine and mill, in the Siskiyou Mountains of northern California, began shakedown operations in the late fall and early winter of 1982. This paper describes some of the unique features in mineralogy, milling, and water treatment operation at Grey Eagle. In addition, major start-up problems in the mill and water treatment plant are discussed along with measures taken to correct these problems.

Jan 1, 1986

By Frank Marotta, Louis B. Lesem, Frank Greytok, John J. McKetta

Although one of the primary variables in the calculation of the flowing bottom-hole pressure in gas wells from surface measurements is the temperature at any point and its distribution in the flow-string, only few experimental data are available in the literature and little attention has been given to analysis of the problem. Virtually all of the recently published methods of calculating flowing bottom-hole pressures depend on the assumption that either the temperature is constant at some average value or that the variation is linear with depth. The purposes of this work are to analyze the problem theoretically and to verify the analysis by comparison with experimental data so that practical problems in the analysis of the behavior of gas wells can be solved with greater accuracy, reliability, and ease. MATHEMATICAL OUTLINE OF PROBLEM Assuming that: 1. The mass velocity and chemical composition of the gas stream are constant and in normal gas well operations, the change in linear velocity in the entire flow-string is trivial, 2. The product of the density and heat capacity of the gas is constant, 3. No horizontal temperature gradient exists in the gas stream, 4. Net flow of heat by conduction within the formation and in the gas stream in the vertical direction is trivial in magnitude and can be neglected, 5. The regional vertical geothermal gradient is constant, and 6. The temperature of the gas entering the borehole is constant, and equal to that of the reservoir, a set of two simultaneous, linear partial differential equations with appropriate boundary conditions was derived to describe the temperature distribution in the gas stream and the surrounding formation. These equations were solved by operational techniques for the distribution of temperature in the gas stream. The resulting integrals were evaluated numerically on an IBM 604 at the Machine Accounting Div. of the Railroad Commission of Texas. DERIVATION OF FUNCTIONS FOR THE DISTRIBUTION OF TEMPERATURE The physical system is a circular hole of radius a in an infinite medium with thermal conductivity K, density p8, and heat capacity c,. Under shut-in conditions the well is in thermal equilibrium with the surroundings and the increment in temperature is given by - ?T3/L x. Gas of density pg and heat capacity c.. flows upwardly through this hole in the direction of increasing x with a linear velocity W. Writing a heat balance on an element of gas ?x in thickness, convective heat transfer + conductive heat transfer + energy required to lift a unit mass of fluid = change in energy content. pa2W po Co To - pa2Wpo Co To x+xx - 2apK?x ?T8/?r r=a - Wpa2 po?x/778 = CoPopa2?x?To/?t... Dividing by (copopa2?x) and taking the limit as ?x tends to zero, -W (?To/?x + 1/778Co) + 2 K/a Po Co ?T3/?r r=u = ?To/?t

Jan 1, 1958

By G. B. Sazuyer

DEVELOPMENTS respecting beryllium during the past year have been sufficient to center attention on it as likely to be the most important of any of the chemical elements that have recently found a place for themselves in technical industry. This importance is only potential, however, largely because adequate supplies of beryllium ore will be necessary. The beryllium industry will be only as great as the mines which support it. To find and develop large mines will be the problem. Chief of the immediate commercial developments in the United States is beryllium-copper and its espousal by Anaconda and Riverside even at present high prices. According to the pamphlets of these companies, it ap¬pears that beryllium is to copper nearly what carbon is to iron. When one considers that the tensile strength of pure copper is about 33,000 lb. per sq. in., but that the addition of 1.5 to 2.5 per cent of beryllium produces a heat-treatable alloy with a maximum tensile strength of 220,000 lb. or over, the analogy to carbon and iron is made strikingly, clear. Striking among the properties of beryllium-copper is its resistance to fatigue, claimed to be equal or superior to that of spring steel. It needs little imagination to foresee a great industry for this alloy alone.

Jan 1, 1934

The Nak?azdli First Nation and the municipality of Fort St. James are located in the Stuart Lake/Nak?al Bun area and are not unfamiliar to mining. These northern British Columbian communities have been associated with the historic Pinchi Lake Mercury mine and today are closely linked with British Columbia?s newest mine, the Mt. Milligan mine. Prior to the construction of Mt. Milligan, community health and social service providers were concerned about potential impacts that would occur from new mineral development activities. This concern has led to a partnership between the above communities and researchers with expertise in the area of mining and health. This paper describes: the current mining and health environment with a focus on British Columbia; mining trends in the Stuart Lake/Nak?al Bun area; the current community-based health research project funded by the Vancouver Foundation and the Canadian Institutes of Health Research, and; a suite of community-based health recommendations to mining companies on key issues to consider when developing projects near municipalities and Aboriginal communities in Canada, based upon one of the newest mines under development in Canada.

Aug 1, 2013

By Cheng Fang, Zhou Lie-xing, Peng Jin-hui, Guo Sheng-hui

This article discusses the behavior of temperature and microwave thermo gravimetric analysis characteristic of ammonium paratungstate in a microwave field. Experimental results show that when 12g of material is place in a microwave with 900W of power, paratungstate’s temperature rises at 70°C/min. This results in paratungstate’s temperature being 980°C after 14 minutes. Compared with thermo gravimetric analysis characteristic, former two-step process of paratungstate microwave calcined completed ahead of schedule, after two-step process reaction is more intense,Paratungstate warming is more rapidly, the reaction time is much shorter; According to XRD and SEM, the product is high purity, the crystal particle size is uniform, and the grain size is fine.

Jan 1, 2015

By M Paakkunainen

Sampling is often the most critical part in process analysis. When the mean of a continuous lot, such as a process stream within a given time interval, is estimated by calculating the mean of several samples, the uncertainty of the estimated mean depends usually on the sampling strategy. Three different strategies can be used: systematic, stratified or random sample selection. The standard deviation of the lot mean is different for these methods so that systematic sampling usually gives the smallest and random sampling the largest standard deviation. Pierre Gy developed a method where the sampling errors of one-dimensional lots for these three strategies can be estimated from a variogram, which is calculated from a variographic experiment, ie from a set of one-dimensional time series measurements with fixed sampling interval. While variogram is an excellent tool for characterising and displaying the variability of autocorrelated processes as function of time, the sampling error estimation from it is quite laborious, however. In this work an alternative method for estimating the sampling errors was developed. The process is divided into strata of equal sizes, varying the length of strata similarly to variographic analysis. For stratified sampling the standard deviation estimates are obtained by analysis of variance and for systematic sampling by fitting a linear regression line to each stratum and calculating the residual variances. By pooling the individual variance estimates the variance estimates that are corrected for autocorrelation are obtained. The new method was tested with simulated and real data sets having periodic, random and/or drift fluctuations. For stationary processes the results agreed well with the results of the GyÆs variographic method. The method can probably be generalised to estimate the sampling variance of higher-dimensional lots.

Jan 1, 2005

By S. Noh, T. K. Kim, B. O. Lee

Future nuclear reactor systems such as a sodium-cooled fast reactor are being designed under severe conditions in terms of operating temperature and irradiation fluence compared to current commercial reactors. For realization of such systems, it is necessary to develop an advanced structural material having both high strength and irradiation resistance at high temperatures. Oxide dispersion strengthened (ODS) steel is considered as one of the most promising structural material because of its excellent creep and irradiation resistance on the basis of uniformly distributed nano-oxide particles with a high density. Up to now, ODS steels have been intensively studied and developed to apply these materials to the in-core structural component of future nuclear systems. Several advanced ODS steels were designed and fabricated by a mechanical alloying, hot isostatic pressing and hot extrusion processes. This study focuses on the effects of heat treatment parameters during the fabrication process parameters on the microstructures of ODS steels for future nuclear system applications.

Jan 1, 2015

By K. R. Miller

In recent years, surface mine equipment operators in the Campbell County region of the Wyoming Powder River Basin have found new ways to solve old problems. This paper will examine overburden stripping equipment and techniques by focusing on evolving applications for draglines, shovels, and dozers.

Jan 1, 1998

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1963 to June 30, 1964 are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1964; in general, the research reported in these publications antedates the report period. Part 3 describes a short-term investigation into safety problems associated with shipping of molten sulfur; this investigation is not at present destined for publication elsewhere.

Jan 1, 1965

By E N. Sparg, O D. A Deuchar, F Needham

Decline shafts are an attractive option to both new and existing mining operations where there is a need to access an inclined orebody deposit via on-reef development so as to generate a return in the shortest possible time. There are many different technologies that are available to transport men, material and rock in incline shafts. This paper focuses on the applicability of two hoisting technologies for decline shafts, namely endless and direct rope systems. The pros and cons of each system are reviewed. A common concern with direct rope haulage systems is the possibility of generating slack rope during deceleration. This paper illustrates the issues involved in designing a system so as to avoid the possibility of slack rope. In conclusion, the key factors relevant to the selection of endless or direct rope haulages for a particular decline application are reviewed. The paper is a joint submission by FFE Minerals-Vecor and Qualter Hall UK.

Jan 1, 2005

By Armin W. Stuedlein, Jim Zammataro, Bernie Hertlein, Daniel Belardo, Qiang Li, Antonio Marinucci

"An experimental program focusing on four drilled shafts was conducted to determine the effect of high strength steel reinforcement bars on lateral resistance, steel casing on axial and lateral resistance, and steel casing without internal reinforcement on lateral resistance. Thermal Integrity Profiling (TIP) Thermal Wires and crosshole sonic logging (CSL) access tubes were installed in each shaft, and thereafter the corresponding non-destructive testing (NDT) was performed on each shaft to assess the integrity of the shafts and to compare the results from the different NDT methods. The results of the CSL tests using scored PVC tubes are compared against those conducted in 73/56 fully-threaded steel hollow bars, whereby the results indicated that the threaded bars served as a good host for performing the CSL tests. The data from the TIP Thermal Wires is compared against the results from the CSL tests for each of the four shafts, and the similarities and discrepancies between the two methods are discussed. This paper will serve as a reference to those interpreting the measurements and data obtained by performing nondestructive integrity tests on drilled foundations.INTRODUCTIONNon-destructive tests (NDTs) embody a set of critical tools for the evaluation of the integrity of constructed deep foundations, particularly for cast-in-place foundation elements. Construction defects may require the rejection of the foundation element by the owner’s representative, resulting in costly repairs or replacements and delays to the project schedule. The use and appropriate interpretation of the results from the NDTs provide the information required when evaluating the integrity of these constructed elements. A cooperative research program was conducted to assess the effects of various construction variables on the axial and lateral performance of drilled shaft foundations, which provided an opportunity to compare the established Crosshole Sonic Logging (CSL) test method to the newer Thermal Integrity Profiling (TIP) Thermal Wire method. This paper presents an overview of the experimental program performed at the geotechnical test site at Oregon State University (OSU), details of the CSL and TIP installation and testing methods, and the results of the NDTs on the constructed drilled shafts. Because one of the shafts was constructed with fully-threaded longitudinal steel hollow bars, this experimental program also allowed the assessment of the use of the hollow bars as access tubes for the CSL tests. Both the CSL and TIP test methods indicated that the shafts were of good quality and free from defects or anomalies; the data obtained using the TIP method also provided an estimate of the as-constructed shaft diameter and the reinforcement cage alignment, which will prove helpful when back-calculating axial and lateral load transfer during future loading tests."

Jan 1, 2016

By George A. Packard

THE experiments here described were made under my supervision while temporarily acting as head of the Department of Metallurgy at the Missouri School of Mines, at Rolla. The work was done by Messrs. W. E. Brown, W. C. Richards, and F. L. L. Wilson, and the description of the results forms a portion of a thesis presented for the degree of Bachelor of Science. These results are submitted because I have seen no description of the application of pot roasting to the treatment of a copper-concentrate. This work followed that already described in the discussion of the ' Lime-Roasting of a Galena-Concentrate,"' and was similarly occasioned by the lack of a furnace of the reverberatory type in which the copper-concentrates could be smelted. The material for the tests was a mixture of three lots available. The first consisted of 8-mm. jig-concentrates and the second of 0.5 mm. table-concentrates, from the San Juan district, Colo. Both contained pyrite, chalcopyrite and galena. The third was a lot of copper-ore, found in the laboratory, which had been crushed through 8-mm. screen, and had at some previous time, before the laboratory roasting-furnace was torn down, received a partial roasting. The analyses of these ores are given in Table I. In order to determine the applicability of pot-roasting as to each lot of ore, and the effect of varying proportions of lime, six preliminary tests were made in a " size N " Battersea crucible, 9 in. high by 6 in. in diameter at top, with a 5/8 in. hole bored through the bottom. The crucible was set in the upturned elbow of a 2-in. pipe, the joint being luted with clay; and air was obtained from a receiver supplied by a compressor. The

Jan 1, 1908

By R. F. Pearce

The paper in based on laboratory and pilot plant investigations which led to the development of a series of processes for production of high purity metals from nickel-copper-cobalt mattes of a wide range of composition. The selection of ammonia pressure leaching or acid pressure leaching for various mattes is discussed. This is followed by discussion of various methods for leach solution purification and metal separation. The metals of high purity are produced by reduction with hydrogen from purified solutions. Examples are given of complete flowsheets for a number of mattes. Drawing upon those examples, general principles for the selection of the most suitable treatment process for particular material are outlined. Under certain circumstances, those processes may replace part of the pyrometallurgical treatment and all of the electrolytic refining steps which are customary in the treatment of nickel-copper-cobalt mattes.

Jan 1, 1959