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By Chris Howell

PotashCorp?s Aurora phosphate mine, in Beaufort County, NC, operates four low pressure boilers and four high pressure boilers to meet its process steam requirements. Maintaining these boilers is critical to meeting production demands. Processing phosphate ore into phosphoric acid requires large amounts of sulfuric acid and steam. Ore is mined from the phosphate deposit with large bucket excavators after 9 to 30 m (30 to 100 ft) of overburden is removed. The phosphate ore is mixed with water to make a slurry that is pumped to the mill. Elemental sulfur is burned in the presence of air to make sulfuric acid. This process is highly exothermic and boilers produce steam while cooling the process. The phosphate ore is reacted with sulfuric acid and the resulting products are refined into different grades of phosphoric acid for fertilizers, feed stock and food additives. Plant operators at the mine were challenged with boiler feed water that was high in silica and other contaminants. As a result, boiler operations were experiencing difficult, labor-intensive operations and equipment deterioration. This resulted in higher operating costs and diminished processing performance. The facility was operating an aged boiler feedwater pretreatment system that included warm lime softening followed by pressure filtration and a cation/anion/mixed bed demineralizer system. The demineralizer required frequent regeneration and chemical usage was high and costs were difficult to predict. Depressurized well water (DPW water), used for plant utility water and boiler makeup, is very high in silica, in the range of 60-70 ppm. Silica can form scale at pressures below 600 psig. Above 600 psig, silica starts to volatize, carrying over with steam to potentially form deposits on downstream equipment and processes. Mine officials decided to upgrade the boiler feedwater pretreatment system to a state-of-the-art reverse osmosis (RO) membrane system. This new system, which started up in March 2009, has improved operating performance and reduced water consumption and overall operating expenditures.

Jan 1, 2011

By Claude Bodeving

The present steel economy drastically increases the financial strain on blast furnace operators. As a consequence, the importance of reliable cast floor operations is increasing drastically, which has a direct influence on the required clay mass and tapping equipment performances. When using modern high performance clay masses, pneumatic taphole drilling machines quickly reach their performance limits, which has made fully hydraulic drill hammers a standard in modern cast house operation. Besides the well-established hydraulic TMT hammers with high impact energy, an alternative version with lower impact energy, but high impact frequency was developed by TMT in the past, in order to achieve improved taphole protection. TMT’s recent research has shown that the drilling requirements inflicted by the taphole condition change over the taphole length, which has triggered the development of a new hammer, capable of switching between a high impact frequency mode and a high impact energy mode.

Aug 17, 2017

By R. H. Storch, D. C. Holt

During reconnaissance investigations of more than 300 stream areas in Idaho to determine the potential value of ilmenite in black - sand placer deposits 46 deposits were explored by churn drilling , trenching , test pitting , or shafting . The component mineral content and total black - sand content were determined for more than 8,690 reconnaissance and exploration samples . Data compiled during the investigation indicate a good potential for large , low- grade deposits containing ilmenite , monazite , columbite , euxenite , uranothorite , and other radioactive black minerals and accessory black - sand minerals . The data also indicate most deposits will be economic only if several component minerals can be recovered as coproducts .

Jan 1, 1963

By Gian Carlo Ticona

El presente estudio plantea una metodología para realizar el criterio de caracterización geomecánica de macizos rocoso alterados, empleando información geomecánica de la franja metalogenética de Andahuaylas – Yauri, este sector es importante para la industria minera en el Perú, actualmente cuenta con el desarrollo de grandes operaciones mineras y tiene una buena perspectiva para el desarrollo de futuros proyectos mineros. En el cinturón de Andahuaylas – Yauri se tiene yacimientos mineros del tipo pórfido – skarn de Cu, Ag y Au principalmente

Sep 30, 2022

By D A. Williams, P J. Chapman

The acceptable rate of rise of the tailings beaches on upstream-raised tailings storage facilities (TSFs) is critical to life of mine planning. This is illustrated through a case study in Western Australia presented in this paper. Accurate estimates of expected beach slopes, the maximum rate of rise at which the tailings can be placed, and the dry density that the tailings solids will achieve after deposition (stored density) are required in order to design TSFs that will allow upstream raises to be constructed safely and economically. Where operations have been occurring for some time, these three parameters are able to be measured and can be well-defined. If process plant throughputs are proposed to increase through mine expansion, for example, increasing the rate of rise of the tailings can compromise the potential for upstream TSF raising, thus influencing the viability of such an expansion, the timing for its implementation, and significantly increase costs.This paper outlines how rate of rise can be a key constraint, and that ‘rules of thumb’ that are typically applied may not result in the outcomes they were meant to achieve. An example of an experimental method to justify an increase to the ‘rule of thumb’ ~2.5 m/year limit for gold tailings in a semi-arid climatic setting is discussed, followed by rate of rise modelling that ultimately framed the decision-making process for a mine expansion. The rate of rise modelling method was adopted to carefully distribute tailings deposition across four TSFs, comprising nine separate tailings cells, in order to maintain appropriate rates of rise. The implications resulting from various deposition splits are presented, including the need for expansion. In addition, this paper outlines the effect of rate of rise on the state (density) of the tailings after deposition, and provides commentary on how anecdotally acceptable rates of rise, based on the aforementioned ‘rule of thumb’ of 2.5 m/year may not provide assurance of geotechnical stability through the tailings achieving a dilative state, as has been thought in the past. An example of the influence of rate of rise on the state of the tailings, with respect to air-drying and the critical state line (CSL) for the material, is presented. The data indicate that reducing the rate of rise may allow a higher dry density to be achieved through air-drying (evaporative desiccation), sufficient to move the material from the contractive to the dilative zone (i.e. from above the CSL, to sufficiently below it).CITATION:Chapman, P J and Williams, D A, 2018. The importance of rate of rise in life-of-mine planning of an upstream raised tailings storage facility – a case study, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 350–360 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Jr. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Jan 1, 2012

By O. S. North

As recently as the late 1920's there Were few indications that a 15-million-dollar-a-year industry would ever grow out of the mineralogic curiosity vermiculite. Today, it is an important industrial commodity, used primarily as an insulating material and lightweight aggregate, but with a wide range of other applications. The quantity of crude vermiculite produced and used in the United States increased 14-fold in the 17 years between 1935 and 1951. The vermiculite minerals are of secondary origin, formed by hydrothermal alteration of an ultrabasic igneous rock, generally pyroxenite, or by alteration of phlogopite or biotite mica or possibly other similar minerals. According to different authorities, vermiculite may originate either by direct hydrothermel means, by the weathering of biotite or phlogopite, or by a combination of these two agencies. Vermiculites frequently occur at or near the contacts of an acid intrusive rock, especially a pegmatite dike, with a basic or ultrabasic country rock.

Jan 1, 1953

By AIME AIME

At the Annual Meeting of the Institute, February, 1908, the following amendments to the Constitution were proposed for action at a future business meeting (see Trans., XXXIX, xxvii) To Art. II. After the first sentence of this Article, add the following sentence « These classes may be subdivided by the Council, according to profession, length of membership, nationality, or other conditions not inconsistent with the provisions of this article." To Art. III. In the first line, substitute " fifteen " for "ten " dollars. At the Annual Meeting of February, 1909, action upon these amendments was postponed to the next business meeting (see Bulletin No. 27, March, 1909, p. xiv). Of these two amendments, the first has been withdrawn, as unnecessary-the subdivision thereby authorized being already practicable without such amendment. The second amendment will be acted upon at the next Annual Meeting, February 15, 1910, and the Secretary has been instructed to call the attention of members to the subject in such a way as to secure a general vote upon it. A special circular, now being prepared by the Secretary, will shortly be sent to all members. Year Book of the Institute. The Year Book of the Institute for 1910 is sent to all members and associates with this issue of the Bulletin. In addition to the lists of members enrolled Jan. 1, 1910, and arranged both alphabetically and geographically, this annual contains lists of officers, council, corporation, past officers, meetings, and notices concerning publications; also the constitution and by-laws of the Institute, and blank forms for proposal of mem-

Jan 1, 1910

By J. Mark Richardson

The use of an integrated software package to simulate and optimize the performance of mineral processing circuits is illustrated by three examples. Each represents application of the software and associated techniques to optimization of an existing plant. In the first example, a South-western U. S. copper company employs the method to simulate and improve performance in crushing, screening and SAG milling. A second copper producer evaluates equipment changes and flowsheet alternatives in a closed-circuit ball mill-cyclone operation. A Southeastern U. S. aluminum refinery optimizes performance of a dry milling and classification circuit for production of carbon particles used in anode casting. Graphical and tabular data describe the circuits simulated and the results achieved in each example.

Jan 1, 1990

By Luis de la Pe[n]a Porth

The present process refers to a method for efficiently obtaining high purity metallic copper from copper ammonium sulfite. Essentially, this process consists of submitting the copper ammonium sulfite to the action of heat and pressure with the object of obtaining by the decomposition of it, metallic copper, ammonium sulfate, sulfur dioxide, and sulfuric acid.

Jan 1, 1974

By André Chagnon, Yvon Héroux

"Résumé - Cette étude porte sur l'altération de la matière organique et des argiles dans les boues carbonatés dévoniennes du faciès ""F"" de la Formation de Pine Point et ses équivalents stratigraphiques la Formation d'Evie et l'unité bitumineuse de la base de la Formation de Horn River. La matière organique se compose principalement de bitume solide et de quelques fragments de fossiles (organo­ clastes). La majorité des échantillons ne renferment que de l'illite et des interstratifiées illite/smectite.Si on compare les températures d'homogénéïsation (Th = l00°C) des inclusions fluides de la sphalérite et des dolomites associées à la minéralisation aux températures estimées à partir de la réflec­ tance de la collinite (84°C à ll7°C), l'on ne peut pas conclure à la présence d'une anomalie ther­ mique dans le district minier de Pine Point. De plus, la réflectance des organoclastes n'est pas plus élevée dans le district minier de Pine Point que dans les localités plus éloignées des gîtes. L'analyse des minéraux argileux conduit à la même conclusion : aucune anomalie thermique n'est décelable dans les unités échantillonnées à l'intérieur du district minier de Pine Point quelque soit l'indicateur utilisé.La kaolinite et la matière organique altérée, affichant des valeurs anomales de sa réflectance, se trouve essentiellement en présence de soufre et de sulfures. Cela suggère une origine authigène de la kaolinite et une altération de la matière organique reliées au phénomènes de minéralisation.Abstract- The alteration of organic matter and clays is studied in the Devonian Pine Point Formation carbonate muds, ""F"" facies, and its lateral equivalents the Evie Formation and the biturninous unit at the base of the Horn River Formation. The organic matter is mainly composed of solid bitumen with few fossil fragments (organoclasts). Most samples contain only illite and mixed layer illite/smectite.If we compare the Th(l00°C) from fluid inclusions of sphalerite and dolomites associated with mineralization to the temperatures calculated from the reflectanœ (Ro) of the collinite (84°C to 117°C), we cannot detect a thermal anomaly in the Pine Point mining district. This result is based on the reflectance values of organoclasts from the mining district that are not higher than those reflectance values measured on organic matter (OM) away from the ore deposit. A similar conclusion is reached from the clay study: none of the parameters used allow us to identify a thermal anomaly in the samples from the mining district.The kaolinite and the altered OM showing anomalous Ro values mainly occur with sulfides and sulfur. This association suggests an authigenic origin for the kaolinite and an alteration of the OM due to the mineralization events."

Jan 1, 1994

By IRVING H. WENTIVORTII

(New York Meeting, February, 1912.) THE little town of San Nicolás, Tamaulipas, Mexico, lies approximately 60 miles east of Linares, situated in the State of Nuevo Leon, and 150 miles SE. of Monterey, as shown in the sketch-map. Fig. 1. The place is reached from Monterey by the Tampico train as far as Linares, a distance of 92 miles, and then by coach the rest of the way. It is situated in a narrow valley between low hills, the houses forming one main street and a plaza. It is peopled by about 500 inhabitants. The climate is temperate, the thermometer ranging from 90° in summer to a few degrees below freezing-point in winter; but this severe weather only lasts a day or two at a time, when the " northers " blow. There are no streams in the vicinity, but water sufficient for the use of the people is obtained from wells. The rainfall is about the same as that in the rest of NE. Mexico. The rainy months are July, August, and September. The rest of the year is practically dry, with an occasional showery day or two during the winter, when a " norther " is blowing. Timber is abundant in many localities. There are two varieties of oak, besides mesquite, ebony, "maguira," "patol," and a number of other kinds of trees indigenous to this region. I. HISTORY. On the discovery of the silver-lead hearing veins occurring in this district, the mining-camp of San Nicolás was founded in 1767 by the Spaniards, and numerous mines were opened and worked for a distance of abort 3 miles east and 5 miles west of the town. At the western extremity and near the Carrolena mine, a small town called San Pedro was built. The ruined walls of the houses form a single street, and all is over-

Aug 1, 1912

The last issue included a discussion of recent indications of a 1983 recovery and a brief analysis of the contribution of the U.S. mining industry to the gross national product (GNP). In this issue we present sales and other data indicating the strength of the 1983 recovery and quantitatively analyze the structural shifts that have taken place in the U.S. economy and mining industry since 1972, and changes in electricity consumption by the mining industry. U.S. Economic Recovery The tentativeness in the February/March issue of Minerals and Materials regarding the strength and sustainability of the U.S. economic recovery can now be replaced with a note of increased confidence. Real growth of GNP on an annual basis in the first quarter of 1983 was 2.5 percent, compared with 1.4 percent predicted in the Economic Report of the President.1/ Preliminary second-quarter 1983 data provide further cause for optimism. Recently released data indicate that consumer spending is playing a key role in the recovery. Retail sales have increased significantly across a wide array of goods, especially consumer durables, where sales increased 4 percent from March to April (table J) and were 12 percent higher in April [ ] than the 1982 monthly average. Consumer durable sales were led by sales of building materials spurred by the growth in residential construction, motor vehicles and parts, and household durables, including appliances and furniture.

Jan 1, 1983

By C Caris, K Fowle, M Schmid, E van Wyk, D Schofield, A Squelch, M S. Kizil

This paper has been written collaboratively by members of the International Mining VR Group. It is the first of a series of papers. Mining in the 21st century is a high technology industry that strives to reduce risk and improve safety through the use of improved processes and procedures. This risk reduction process is aligned with the innovative use of technologies often developed for other industries. Computer-based visualisation systems and their content are such innovative technologies, in particular the use of virtual environment systems and mixed reality. A primary objective of developing virtual environment systems and the mixed reality content displayed in them for the mining industry is to allow mine workers and operators to practice mine processes and demonstrate competency in tasks that will be encountered in day-to-day mining operations at mine sites. It is anticipated that providing easy access to virtual environment systems will facilitate the avoidance of high-risk situations through improved knowledge, skills, understanding and decision making. Via virtual environment systems mine workers will also be able to practice infrequent or emergency events and maintain preparedness for such events. Day-to-day mining practices can also be evaluated. The rapid pace of technology innovation and the decreasing cost of simulation hardware and software present a plethora of technology to the uninitiated. This can be confusing. In this paper taxonomy is presented that classifies hardware, what it can display and also content that can be included or displayed on the various computer-based visualisation systems. The taxonomy provides insight into where technology can and may be implemented in the future as virtual environments are a dynamic and evolving technology. The taxonomy should also assist in the decision making process when scoping or selecting technology for a particular purpose.

Jan 1, 2008

By E. M. J. Alenius

This paper describing the mining practices at the United Verde open-pit mine at Jerome, Ariz., is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts in the United States. The purpose of this paper is to present the methods used in developing and operating the mine, and to discuss the problems encountered.

Jan 1, 1930

By G. L. Oldright

This paper is the fourth of a series of preliminary papers on smelting in the lead blast furnace.4 The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation and to correlate these conditions with operating factors, furnace behavior, and metallurgical losses. ACKNOWLEDGMENTS The authors wish to express their appreciation to the management of the International Smelting Co. at Tooele, Utah, for their whole-hearted cooperation in this investigation.

Jan 1, 1929

By M. J. Raffaldi, K. W. Harris, K. A. Perry

"Highwall miners have been widely used to extract additional coal reserves from existing surface operations, particularly on contour operations in the Appalachian coalfields. Using a continuous miner cutting head, coal may be extracted from significant depths (such as 150 m), leaving behind an array of web and barrier pillars with the purpose of maintaining highwall stability. This method inherently involves elevated risks to both equipment and personnel due to proximity to and increased exposure time near highwalls. As a result, modern operations should actively design web and barrier pillars to maximize extraction while providing adequate stability. The ARMPS-HWM software, an empirical-based program created for the design of web and barrier pillars at highwall mining operations, is one such approach. The calculated stability factor is compared with empirically established guidelines produced from examining case histories.The ARMPS-HWM program is a handy tool for initial design, but understanding the site’s structurally significant geologic features and geomechanical behavior is important and may potentially increase extraction. We created a two-dimensional numerical model using FLAC3D and calibrated it to ensure pillar strength, closely following the Mark- Bieniawski formula for a typical range of pillar geometries and overburden properties. The development of pillar stresses along a highwall panel was then numerically investigated as mining progressed, and the stress distribution between barrier pillars was found to be asymmetric, which can result in an over-design of the closeout web pillars if tributary area loading is assumed. Finally, the importance of adequate barrier pillar stability is highlighted."

Jan 1, 2014

By J Nell, J Petersen, X C. Goso

The feasibility of increasing the deportment of titanium species and the stability of the pseudobrookite solid solution (M3O5) in a titaniferous slag was investigated, to facilitate the valourisation of titaniferous slags. Thermochemical simulations using FactSage™ software, ver 8.3 (by Thermofact/CRTC and GTT-Technologies), and equilibration-quench experiments were conducted using an appropriate synthetic titaniferous slag composition in an oxygen partial pressure (pO2) ranging from air to 10-16 atm under non-isothermal conditions. The temperature-pressure phase stability diagram for the synthetic slag containing 37.19 per cent TiO2, 19.69 per cent SiO2, 13.12 per cent Al2O3, 16.00 per cent CaO and 14.00 per cent MgO showed that the spinel solid solution (M3O4) was the primary phase until a pO2 of 10-10.5 atm, thereafter M3O5 was the primary phase until a pO2 10-13.2 atm. M3O4 again was the primary phase between a pO2 10-13.2 and 10-16 atm. The changeover of the primary phase coincided with an increase in the liquidus surface. When cooling the slag in a pO2 of 10-16 atm, M3O5 crystallised as a ternary phase that showed a rapid increase in mass while that of the primary M3O4 phase decreased and that of the secondary perovskite (CaTiO3) phase increased at a slower rate. At 1300°C under sub-liquidus conditions, the contents of M3O5, M3O4 and CaTiO3 were about 20 per cent, 15 per cent, and 11 per cent, respectively. Experimental results showed that the Ti3+/Ti4+ mass ratio in the M3O5 phase, ie a measure of the reduction of titanium species, is not considerably sensitive to equilibration temperature in the reviewed range. Slow cooling and minimum/no oxidation during cooling of titaniferous slag would increase the deportment of titanium species to, and the growth and stability of the M3O5 phase.

Jun 19, 2024

Structural analyses of oriented bore core sections from the West Wallsend No.2 Colliery Holding together with investigations in adjac- ent collieries and on the surface delineated structural phenomena. The rocks examined are anisotropic due to strongly developed bedding planes and the presence of penetrative joint planes. Joints, in this context, are regarded as mechanical discontinuities, they are genetically identif- ied wherever possible and their spatial attit- udes are determined and geometrically related to the regional structure. Identifiable anisotropies in the roof- and floor-strata of the Borehole Seam render favour- able mining directions for longwall and bord and pillar layouts.

Jan 1, 1972

By W. H. Kerns

The Taylor Creek lead-zinc deposit is on Taylor Creek, approximately 1-1/2 miles from tidewater, at the head of Duncan Canal, on the east side of Kupreanof Island, Petersburg district, southeastern Alaska. The property was located in 1903, and a 30-foot discovery cut was put to the west tank of the creek. Very little prospecting end developing has been done since that time. The property was examined by J. C. Roehm, associate mining engineer, Territorial Department of Mines, Juneau, Alaska, in June 1946. From exposure n the creek, a mineralized zone with possible dimensions of 1,700 feet by 1,000 feet was indicated. The general strike was northwest, and the dip was low and variable to the northwest. During September through November 1948, the Bureau of Mines conducted a project on the property. Four diamond-drill holes, totaling 770.5 linear feet, were drilled from the surface and 280 lineal feet of hand trenching done. The mineral deposit was found to occur as patches that appear to be a replacement in dolomitic limestone. The patches of mineralization are small, irregularly shaped, and irregularly distributed. Maps showing the location of the drill holes and trenches, analyses of the cores from the drill holes, and anal lee of the samples from the trenches accompany this report (see, also, appendixes A, B, and C).

Jan 1, 1950