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Low Zinc Prices Close Alcoa Mine Alcoa Mining Co., announced that it will suspend operations at its Hutson mine, near Salem, Ky., because of low zinc prices, January 15. The Aluminum Co. of America subsidiary announced that the low market has made zinc mining un- profitable. About 70 men were employed at the mine, with a production of about 5000 tons of zinc annually. Alcoa said the shutdown would not affect other company operations, with most of the men at Hutson absorbed in the mining firm's fluorspar operations in the same area.

Jan 2, 1953

By T. Hidayat, D. Shishin, S. Sineva, M. Shevchenko

The effects of the slagging components Al2O3, CaO and MgO on the thermodynamics and phase equilibria of the gas/slag/matte system with major elements “Cu2O”-“FeO”-SiO2-S are characterised using an integrated experimental and thermodynamic modelling approach. The experimental technique included high-temperature equilibration experiments using a spinel substrate in controlled gas atmosphere (CO/CO2/SO2/Ar), quenching of the sample and subsequent measurement of the compositions of equilibrium phases with Electron Probe X-ray Microanalysis (EPMA). Thermodynamic modelling is undertaken using the computer system FactSage. In previous experimental studies on this system, the separate effects of Al2O3, CaO and MgO were determined. In the present investigation, the combined effects of these additional components are investigated at 1200oC and P(SO2) = 0.25 atm and a range of P(O2)’s. Special attention is paid to ensuring chemical equilibrium is achieved in each case, for this reason possible kinetic factors are systematically analysed. The results obtained are presented in the form of graphs showing the compositions of matte and slag phases as functions of copper concentration (matte grade). The new experimental data are used for the improvement of the thermodynamic database for multicomponent copper-containing systems. The effects of the slagging elements on this multicomponent system will be presented in the paper. INTRODUCTION Whilst Fe-O-Si form the principal components of copper smelting and refining slags, additional impurities are present in industrial practice typically at 2–5 wt.% Al2O3, 1–4 wt.% CaO and 1–2 wt.% MgO levels (Davenport, King, Schlesinger, & Biswas, 2002). These elements are introduced into the slag as impurities in concentrates and other feedstocks, in fluxes added to the process and in refractory materials. Understanding, and accurate description, of the changes that take place in the smelting process in the presence of these additional elements is of major importance to the optimization of industrial operations. Although experimental data are available on slag/copper matte equilibria, further work is needed to accurately characterise the influence of Al2O3, CaO and MgO on phase equilibria and elemental distributions of elements in gas/slag/matte systems. The individual effects of the Al2O3, CaO and MgO slagging components on equilibrium phase assemblages under selected conditions have been quantified in a recent series of studies on the Cu–Fe–O–S–Si-(Al, Ca, Mg) gas-slag-matte-metal system (Fallah- Mehrjardi, Hayes, & Jak, 2018; Fallah-Mehrjardi, Hidayat, Hayes, & Jak, 2017a, 2017b; Hidayat, Fallah-Mehrjardi, Hayes, & Jak, 2018a, 2018b; Jak et al., 2016; D. Shishin, Decterov, & Jak, 2018; Denis Shishin, Hayes, & Jak, 2018). Since, thermodynamically, the condensed phases do not behave ideally, it is to be expected that the effects of individual elements may not be additive, and the additional interactions between the Al2O3, CaO and MgO slagging components will also have to be taken into account. These additional effects are expected to be smaller than those of the individual components, so higher accuracy is needed. The present paper describes analysis of the precision and accuracy of the experimental technique on multi-component, multi-phase equilibria in these systems to enable the combined effects of Al2O3 + CaO + MgO on slag/matte/spinel equilibria, i.e. for high Fe/SiO2, to be accurately measured. The effects of Al2O3, CaO and MgO on the gas - slag - matte are analysed using a thermodynamic modelling approach with the computer package FactSage.

Jan 1, 2019

By Robert H. Ridgway

This circular outlines salient facts regarding the manganese-ore industry in the United States and the world. It is founded chiefly upon published information available in the literature of the subject. The Bureau of Mines has in its files additional, more detailed data upon many of the topics presented very briefly here, and will endeavor to assist the mineral industries and public by giving further information in response to individual inquiries. The Bureau will welcome comments, criticisms, and contributions of data that may assist in making later additions of this circular more accurate, or in developing more fully its mineral files pertaining to manganese. In reporting the production of manganese-bearing ores in the United States the following classification has been adopted by the Bureau of Mines: (1) Metallurgical-grade ores, under which have been classified manganese ores containing 35 percent or more of manganese used in the manufacture of iron and steel, ferruginous manganese ore containing 10 to 35 percent of manganese, manganiferous iron ore containing 5 to 10 percent of manganese, and manganiferous zinc residuum; (2) battery ore; (3) fluxing ores, under which are classified ores that may contain a few ounces of silver and are rich enough in manganese to make them valuable chiefly for fluxing purposes in nonferrous smelters; and (4) miscellaneous ores, under which are classified the ores shipped to brick manufacturers, glass makers, and manufacturers of manganese chemicals.

Jan 1, 1933

By Edward W. Parsons

Conventional rock-bolt anchors often fail when installed in weak formations. The purpose of this work was to develop an anchor that would utilize an explosive charge to secure anchorage in any type of rock. Laboratory work to develop a rock-bolt anchored by explosive forming was initiated using rock-bolt models which had a drilled explosive chamber and were composed of various metals. This was followed by the use of several types of seamless tubing which were expanded with a water-coupled explosive capsule. By attaching a length of solid bolt to the anchor tube, a prototype explosive-anchored rock bolt was made. More than 150 laboratory models were expanded during this phase of development, During two field tests in underground mines (A and B) and one in an open- cut mine (C), 87 explosive-anchored bolts, 9 slot-and-wedge bolts, 2 bolts anchored with expanding grout, and 28 expansion-shell bolts consisting of three types of shells were installed and subjected to pull tests. The field tests were run to determine the effects of variables such as the amount and placement of the explosive charge, design changes in the bolt, and the effect on anchorage of different pull-test techniques. The field tests revealed the following: Mine A. The explosive-anchored rock bolt was feasible, but changes were necessary in bolt materials and in some details of bolt design. Mine B. The design and materials of the bolt gave excellent results in hard fractured rock, but no information was obtained concerning variations in the dimensions of the anchor unit or in the explosive charge. Nine C. Varying the explosive charge to produce a beaded surface on the bolt tube and tightening of the anchored bolt before pull-testing were found to increase significantly the anchorage obtained in soft ground.

Jan 1, 1963

By Dale Preece, Ayman Tawadrous

This paper presents a number of examples of three-dimensional blast modeling in both surface and underground environments that include time-delay explosive decking. These examples include: 1) quarry blasting, 2) coal seam protection blasting, 3) mineral mine blasting with high energy time delayed decks, and, 4) underground single-level/single-shot drawbell blasting.

Jan 1, 2014

By W. T. Benson

The Bureau of Mines has examined selected deposits of titanium minerals throughout the United States. The titaniferous magnetite deposits in the western San Gabriel Mountains, Los Angeles County, Calif., were among those selected for study, and in 1956-58 field work was conducted to determine the extent and character of the titaniferous magnetite deposits occurring in the area. This report describes this work and summarizes earlier work in the area by the Bureau and others. The titaniferous magnetite occurs disseminated as seams and lenticular pods in an anorthosite belt 4 to 6 miles wide that trends about. N. 80° W., extending from sec. 13, T. 3 N., R. 12 W., to the west boundary of R. 14 W., at which point the titaniferous magnetite-bearing rocks disappear beneath the sediments in the Santa Clara River Valley.

Jan 1, 1962

By Oliver Finn

Gold dredging has made such rapid strides of late and there is such a widespread interest in this branch of mining that I venture to contribute a detailed account of the way in which a Keystone driller was used by me in California to loosen, by blasting, a very tight gravel deposit, preparatory to dredging. There is a great difference between “cemented gravel” and “tight gravel.” A truly cemented gravel is not a dredging proposition, while the tightest possible gravel, where there is no cement, can be made easy working by the following method of blasting:

Jan 1, 2008

By Y. M. Jubeli

"Abstract - Gamma-ray spectrometry, an effective tool in geological mapping, was used to define boundaries between various lithological formations in three adjacent areas of Central Syria, namely, the Syrian Desert, Ar Rassafeh Badiayat and the Northern Palmyrides mountains. This paper describes the role of an airborne gamma spectrometric survey which was orginally undertaken to assist uranium exploration. Interpretation of the total count data obtained through the survey has led to significant modifications and corrections to the previously published distribution map of the palaeogene phosphate rocks.Another important result of the survey is the discovery of four previously unknown phosphorite horizons in the Rasm Al-Aawabed area of the Northern Palmyrides. In addition, previously unknown phosphatic horizons are outlined in the other study areas. The importance of this technique as an effective prospecting method, not only for U but also for exploring for the economically important phosphorite formations in Syria, is emphasized. Furthermore, its role in geological mapping is stressed, especially in areas that lack sufficient geological data."

Jan 1, 1997

OZ Minerals Limited owns and operates the Prominent Hill Copper-Gold Mine, located 140 km southeast of Coober Pedy in far north South Australia. The Prominent Hill mine comprises an open cut mine with an initial 10 year mine-life and an 8 Mtpa conventional grinding and flotation plant to produce high quality copper-gold-silver concentrates, which are exported by road to local customers and by rail to the port of Darwin for shipment on to Southeast Asian smelters. Mine and process operations at Prominent Hill are licensed to abstract a water supply of up to 26 ML/d, sourced from a borefield located 40 km and extending to 80 km east of the mine. The arid climate of the broader Prominent Hill region means that groundwater is important for sustaining community and pastoral industries in the region, and security of water rights for third party users is a critically important water management issue posing a significant challenge to the development of Prominent Hill. Depth to water table and the typically high salinity of groundwater in the region means there is little environmental dependence on groundwater within the immediate Project area (mine lease and wellfields). The Prominent Hill mine and associated infrastructure lies within the South Australian Far North Prescribed Wells Area (FNPWA), which was principally defined to ensure the ongoing security of the ecologically, socially and culturally significant GAB springs, of which the closest are found around 150 km northeast of Prominent Hill, and only 50 km northeast of the water supply borefield. Prescribing of the FNPWA meant that OZ Minerals was required to demonstrate to both State and Federal Government agencies that the mine's water supply is independent of that which supports GAB springs and other third party water users in the region. Recognising these potential obstacles, OZ Minerals successfully defined and developed a previously unknown industrial quality groundwater resource, separate from other important groundwater resources in the region that supply community, pastoral and environmental users, ensuring third party water user sustainability.

Jun 1, 2010

Some 800 analyses for Cu, Zn, Pb, Ag, Fe, S, CaO, MgO, C02, Si02 and Al203 were used to examine the elemental constitution of the Mount Isa ores, and, for comparison, those of the Northern Leases area.Lead: zinc relations show little order from sample to sample, but means of large zones (Le. individual orebodies) show a highly linear inverse relationship. Lead: silver ratios are fairly constant from sample to sample, and means show a highly linear direct relationship.Sulphide sulphur appears to be related to carbonate and alumina abundance, sulphur decreasing systematically with increase in the ratio CO2:AI203. In all graphs involving members of the group CO2-A203-S the lead-zinc and copper ores conform to the same simple trends, confirming that the two ore types and their host rocks are genetically closely related. The earlier deduction of a volcanic-sedimentary origin for the sulphides of the Black Star orebodies appears compatible with present findings.On the basis of such an origin, the pattern of sulphide occurrence and mineralogy in the Mount Isa district is possibly related to the configuration f the upper surface of the "Eastern Creek Volcanics", the facies patterns of the overlying sedimentary rocks, and to the oldest faults affecting the two.INTRODUCTIONStanton (1962) described and interpreted the chemical constitution of the Black Star No. 2 lead-zinc and the 650750 copper orebodies at Mount Isa. The investigation has now been extended to the other principal orebodies of the area.The earlier study showed that the host rocks of the two adjacent Black Star orebodies were constitutionally closely related, and suggested that this was probably due to their original formation in contiguous zones of sedimentation. On this basis the silica-dolomite of the copper ore appeared to represent the slightly more shoreward, "limey" member, probably a fairly massive algal calcareous sediment laid...

Jan 1, 1963

By Frank Firmstone

IN the early decades of the past century the method of starting iron blast-furnaces by "scaffolding-down" seems to have been in universal use for coke-furnaces and, at least in this country, for charcoal-furnaces also. It was likewise used at some of the early anthracite-furnaces, as is stated in the important "Reminiscences" printed by the late Samuel Thomas. I It had been generally superseded in Great Britain as early as 1850, by some variations of the plan now used, and was rarely used when Percy wrote.' On the Continent it was still followed in the 60's,3 and was elaborately described by Valerius in 1852. I have never read any statement as to when and by whom '4 scaffolding" was first dispensed with, but the following extracts from journals of my father seem to fix an authentic date for an instance in this country:

Mar 1, 1907

By Y. S. Sun, Northeastern University, W. B. Li, P. Gao, Z. Y. Zhang, J. W. Yu

"The boron-bearing iron concentrate was extracted from ludwigite ore by the process of magnetic-gravity separation. In order to fully utilize the refractory ore and meet the boron consumption of China, a novel process for separation of boron from iron in boron-bearing iron concentrate was proposed in this paper. In particular, laboratory scale experiments of improving boron reactivity were performed. Fine boron-bearing iron concentrate briquettes were reduced by bituminous coal completely at 1125 °C for 150 min. The effect of sodium carbonate, which was used as an additive in the roasting process, was investigated. The addition of sodium carbonate decreased the boron reactivity and facilitated the volatilization of boron. The influence of diverse cooling methods of the reduced samples on the boron reactivity was studied. The results indicated that boron reactivity could reach up to 80.76% when the reduced samples were cooled by rapid water quenching. In addition, the magnetic material containing 92.71 % Fe with a recovery of 95.11 % and boron-rich non-magnetic material containing 14.51% B2O3 with a recovery 88.85% could be obtained by low-intensity magnetic separation. The magnetic material and boron-rich non-magnetic material were good raw materials for steel-making and borax production, respectively.INTRODUCTION Ludwigite ore is abundant in Liaoning province of China, with 28.43 Mt B2O3 accounting for 57% of the boron resources of the country (Liu et al., 2006). However, it has not yet been utilized on an industrial scale due to its complex mineralogy and fine mineral dissemination (Wang, Wang, Ding, Ma & Xue, 2012). At present, boron-bearing iron concentrate and boron concentrate can be obtained from ludwigite ore using magnetic-gravity separation. The boron concentrate contains B2O3 12%~16%, which can be used as a high-quality raw material for the boron chemical industry after activated roasting, but the B2O3 content in the iron concentrate reaches up to 4%~6%. In order to further separate boron and iron from boron-bearing iron concentrate, a blast furnace and a solid pre-reduction followed by electric arc furnace melting have been proposed (Liu, Cui & Zhang, 1998; Wang et al., 2012). However, both of these two current routes face the same crucial problem that molten boron-rich slag has to be cooled slowly to obtain the alkali-dissolution activity of boron, which affects the yield of boron resource."

Jan 1, 2016

By Eric E. Ungar

Some fundamental facts regarding noise are summarized. Guidelines for reducing plant noise are indicated, and simple means are discussed for determining, whether quieting of specific equipment items will reduce plant noise significantly. Design and installation recommendations are made for quieting chutes by means of dams, impact cushioning pads, impact shields, and damping materials, and for quieting; screens by means of resilient decks, lined screen bottoms, drive mechanism enclosures, and side plate additions. A brief account is appended of the wear and productivity performance of resilient materials observed in three cleaning plants.

Jan 1, 1976

In 2005, CANMET-MMSL used its pool of expertise in ground control, open pit and underground mine engineering, mineral processing, information technology and applied mineralogy to launch a mine-to-mill research project. The objective of the project was to optimize the distribution of rock breakage energy among blasting, crushing and grinding activities, thereby maximizing the efficiency of energy utilization within comminution processes. Tests were designed to demonstrate that this approach could reduce energy consumption, thus contributing to the reduction of green house gas (GHG) production in the Canadian mining industry. The project was accomplished in collaboration with DynoConsult and Dyno Nobel Canada Inc., a world leader in commercial explosives. Data analysis from 12 blasts (six with electronic and six with pyrotechnic detonators) in three different geological formations of a quarry (soft, medium and hard rock) shows that electronic blasting technology increases rock fragmentation by 15% (in hard rock) to 20% (in soft rock). A more uniform rock fragment size distribution is also obtained. The impact of the improved quality blast product on downstream processes of the quarry is a productivity increase of 5% in rock excavation and transportation, an energy reduction of 10% at the primary crusher and an increase of 15% of the primary crusher throughput. Extended to the Canadian mining industry, such results would represent a GHG emission reduction of about 0.05 Mt/y. A soft-sensor prototype, based on primary crusher data (i.e., energy consumption, throughput, feed and product size distribution) and a simplified computerized process model, was developed for on-line measurement of the rock operating work index. Additionally, 385 rock samples and specimens were collected and prepared to determine the tensile and compressive strength of the rock material, to evaluate the aggregate crushing work index and to examine the development of micro- and macro-fractures by means of binocular and SEM microscopy. Blast-induced rock damage was evaluated at the end of the laboratory-testing program. Even though a reduction of rock hardness of around 30% was observed after blasting, the impact of the blasting method (i.e., use of electronic or pyrotechnic detonators) on the induced rock damage could not be observed. It is either absent or not perceptible with the accuracy of the measuring techniques and the number of samples analyzed.

Jan 1, 2008

By William Van Impe

A most renewing and promissing soil displacement screw pile is called the O-pile. The O-screw pile is a soil displacement auger pile based on a screwing in - screwing out procedure. The displacement auger head consists of a discontinuously diameter - increasing steel tip, on top of which the continuous screw flange with variable pitch is mounted. The soil displacement is kinematically ensured by downwardly oriented slots mounted on the auger head at different well chosen locations on the flanges. This leads to a very efficient lower energy screwing-in sequence of the pile and consequently to a high penetration rate. A test loading program of instrumented O-piles has been carried out in order to evaluate the load settlement behaviour, the shaft and tip capacity of the O-pile, including its specific installation parameters.

Jan 1, 1996

By Thomas J. Lien

Granitic Pegmatite deposits are the chief source of commercial feldspar, micas, lithium minerals, tantalum-columbium, beryl, and certain types of kaolin. The output from pegmatite mines in the United States is small compared to other mineral products in terms of bulk or value, and much of it comprises only minor metals and nonmetals. Nevertheless, pegmatite minerals play a vital part in our domestic industrial economy, particularly in the ceramic and electrical industries. Numerous special purpose uses also are important, even though they require small quantities of raw materials. In recent years, realizing the potential importance of the pegmatite minerals, the U.S. Geological Survey, the United States Bureau of Mines, several state Bureaus of Mines, and a few private companies have carried on extensive programs of pegmatite studies in the New England and southeastern states, in the Black Hills area of South Dakota, in the Rocky Mountain region of Wyoming, Colorado, and New Mexico, and in various parts of Washington, Idaho, Utah, Nevada, Arizona, and California. Currently, some of the pegmatite minerals such as micas and spodumene are selectively separated by the flotation process. To a lesser extent a few plants are selectively floating feldspar and quartz. Much of the credit for the above progress goes to the fine work done by U.S. Bureau of Mines (1), and companies such as Foote Minerals (2). Additional research efforts by the New Mexico Bureau of Mines (3) has successfully demonstrated selective separation of micas, beryl, spodumene, lepidolite, microlite, quartz and feldspar from a complex Pegmatite containing all these minerals. Since the nature of the mineralization of various valuable components of a pegmatite deposit is such that selective separation of some of these can be carried out at a coarse size using the Heavy Media Separation technique, it was felt that such a system should be investigated for selective preconcentration of their minerals. It was also felt that of all the :MS systems available, the DYNA WHIRLPOOL (DWP) device which allows a close control and adjustment of specific gravity should provide a means of achieving the above goal. Once the desired preconcentration of one or more of the pegmatite mineral assemblage is achieved, the available selective flotation techniques should provide effective recovery of various minerals into marketable products. This paper presents technical and economic aspects of selective preconcentration of some of the pegmatite minerals followed by selective flotation to produce marketable products.

Jan 1, 1978

By Richard E. Thill

Elastic wave velocities and moduli were determined by both the pulse and resonance methods in a large number of specimens of St. Cloud Gray Granodiorite and Tennessee marble under the same moisture, temperature, and stress environment. Long cylinders were first tested by the resonance method to obtain longitudinal bar and torsional wave velocity. The cylinders were then sectioned in half and tested by the pulse method to obtain the transient pulse velocity. These velocities were later used to obtain various moduli for comparison. Statistical comparisons between the Young's, shear, and bulk moduli and Poisson's ratios obtained independently by the pulse and resonance methods indicate that the methods do not give equivalent results in nearly isotropic rock. The amount of difference varies for each modulus, with the least difference (less than 5 pct) occurring in the shear modulus and the greatest difference (as high as 34 pct) in the bulk modulus. Moduli determinations in aluminum show much closer agreement between the pulse and resonance methods than in rock. The discrepancy in pulse and resonance results probably is caused by frequency dispersion effects and by differences in error sensitivity in the various formulas used to calculate the moduli.

Jan 1, 1974

By Carlos Pineda

El presente trabajo describe la integración de las herramientas Whittle. 4X en la planificación a largo plazo de la mina Pierina. El uso de la informática en las etapas de planeamiento se realiza a través de software especializados con aplicaciones CAD y comunes: Kedit, excel, access, etc. Asimismo, la planificación a largo plazo se vincula a las fases del minado, cuyo objetivo es la optimización los recursos conocidos de la mina, así como los resultados economicos de la explotación del yacimiento a través de la optimización del límite final.

Aug 25, 2002

By Richard D. Lang

Introduction Argyle is located in the Kimberley region in northwest Australia (Fig. 1). It is a significant diamond discovery by world standards and is the first major diamond find in Australia. The deposit consists of a pipe and associated alluvial deposits. Before the 1970s, diamonds were known to exist only sporadically in Australia. They have been found occasionally in association with gold deposits in Western Australia. There is a small deposit near Copeton in New South Wales. Some alluvial occurrences have also been found in Victoria, South Australia, and New South Wales. The first indicator minerals in the Kimberley region of Western Australia were discovered in January 1973. Production from the alluvial deposits at Argyle began in 1983. A $430-million construction program to develop a mine and treatment plant capable of producing 25 million carats per year was completed in December (1 carat = 0.2 grams). Ownership and management Participants in the project are known as the Argyle Diamond Mines Joint Venture. The group consists of CRA Ltd., 56.8%; Ashton Mining Ltd., 38.2%; and the Western Australian Diamond Trust (formerly Northern Mining Corp.), 5%. The project is managed by Argyle Diamond Mines Pty. Ltd., a wholly-owned subsidiary of CRA. Marketing is undertaken separately by the Western Australian Diamond Trust and by Argyle Diamond Sales Ltd. (for CRA and Ashton Mining groups). History Ownership of the Exploration Joint Venture has changed over the last 12 years as various parties changed their shareholdings. The original Kalumburu Joint Venture was formed in 1972 with five participants, each holding a 20% interest. By 1983, a number of ownership changes had occurred. The end result is that two original participants have sold out. CRA now holds a 56.8% share and the Ashton Mining Group holds 38.2%. CRA also assumed project management in January 1977. Table 1 demonstrates the long lead times involved in developing a project.

Jan 1, 1986

By DeVerle Harris

The enthusiasm with which individuals have participated in mineral exploration in the development of this country testifies to the fact that there was once a very real probability of making a worthwhile discovery. Over the years, the discovery and subsequent exploitation of the accessible ore deposits have made the finding of new deposits progressively more difficult. Present day mineral exploration has evolved from the lone prospector with the grubstaker behind him to a very costly and complex business, involving large sums of money and a staff of experts in the fields of exploration technology. Exploration today must be carried out on a large scale to be profitable. With the involvement of large amounts of capital, there has been a good deal of interest in methods of optimization of the allocation of the resources of a firm 'engaged in mineral exploration. As a step toward this, mathematical models have been formulated which are designed to quantify those variables of mineral exploration in such a manner that they can be integrated with all phases of the firms operations so as to optimize its profit objective or more simply, to make exploration more efficient and effective.

Jan 1, 1964