Search Documents

By H. P. Cole

A team of researchers at the University of Kentucky, working under a USBM contract, developed over 65 simulation exercises for teaching and testing problem-solving and decision-making skills to miners and mining engineers. These skills involve both improving judgment and decision making in mine emergencies and enhancing the learning of real-world engineering design principles. The exercises are ideally suited for either latent image format or for computer-aided instruction. Exercise features are summarized, the structure and field testing of typical exercises described, and sample frames of individual exercises presented. Empirical data are summarized that describe the effectiveness of using these short, time-efficient performance tasks that simulate real problems and that provide immediate corrective feedback for teaching and testing critical skills. I

Jan 1, 1991

By S. K. Kawatra, Harrison R. Cooper

In the last 30 years, on-¬stream slurry analyzers have proven to be of great use in the control of mineral processing circuits. This review discusses the two most popular methods, x-ray fluorescence and neutron activation analysis, and also considers techniques which are still under development.

Jan 1, 1986

By Clyde M. Pearce

This paper describes the facilities at Pointe Noire, Quebec that Wabush Mines utilizes for the receipt, distribution, stockpiling and shipping of iron ore concentrate and pellets. The main topics to be covered will be: 1. - General description 2. - Concentrate receiving facilities 3. - Conveying circuits 4. - Stockpiling 5. - Vessel loading GENERAL DESCRIPTION The map of the eastern Quebec - western Labrador area as shown in Appendix #1 shows the location of Wabush Mines properties. You will note the Scully Mine located at Wabush Lake, Labrador, 235 miles north of the town of Sept-Iles, Quebec. Our neighbors, the Iron Ore Company of Canada have their properties further north at Shefferville, near by at Carol Lake and at Sept-Iles. To the Southwest, our other neighbors, Quebec Cartier Mining, have their iron ore processing facilities and their terminus on the St-Lawrence at Port Cartier. Concentrates are prepared at the scully Mine by mining, crushing, grinding, concentrating, drying and high tension separation for shipment by rail to Pointe Noire, Quebec. Pointe Noire is situated across the bay from the town of Sept-Iles, Quebec on the North Shore of the St-Lawrence River. The concentrate consists of 66% iron, 2 ¼ percent silica and practically no moisture, permitting the use of specially constructed railroad cars and handling facilities to convert the concentrate into pellets, the final product.

Jan 1, 1967

By Joseph W. Leonard

By combining statistical methods with specialized coal technology, novel and widely applicable procedures are developed which are useful for making important decisions based on coal seam structure. By analyzing such properties as ash in visual coal types of seam cross sections and by processing the ash data to 100 gram increments of coal ranging from the top to the bottom of the seam, intraseam comparisons between data populations of samples from a given seam and a reference seam can be made. Moreover, illustrations are presented for estimating the number of drill cores required to purchase a specified level of sampling accuracy together with procedures for determining the probability that different coal scan cross sections are not unlike and by inference are therefore comparable. Such comparisons can be valuable when making important, costly and long prevaling decisions involving coal exploration, mining, preparation and utilization.

Jan 1, 1969

By Leon D. Keller

Fine screening, as discussed in this paper, pertains to the use of the Rapifine DSM Screen to make a 65 to 325-mesh separation at production tonnages. The greatest number of Rapifine Screen installations are in magnetic taconite plants where the unusual relationship between the grinding mill, cyclone classifier, magnetic separators, and fine screens makes the Rapifine Screen application unique. Since the initial fine screening installation on magnetite in 1961, (1) additional installations and further testwork have contributed to the fund of information which is the basis of this paper. The addition of fine screens to the grinding-classifying circuit of a magnetic taconite plant creates a change that effects all components of the circuit. Pine screens in a non-magnetic plant have also been investigated, but here the benefits have not' been as clearly defined. Screens classify according to the particle size. Hydrocyclones classify by a combination of particle size and particle weight. The change in the type of classification minimizes overgrinding of the mineral. The resultant savings in grinding power can be used to increase the throughput, upgrade the product, or increase recovery.

Jan 1, 1971

By J. Duran

Mining at Phoenix is currently done by surface operation in the Fortitude and Bonanza Pits, at a combined rate of approximately 110,000 tons per day. A portion of the ore bodies targeted by these pits was mined previously by underground mining methods, dating back to the mid to late 1800?s. Most of the underground workings (voids) are located in the west central area of the Bonanza Pit. The surface operation requires excavation through voids, and there is a risk of pit floor subsidence that has to be addressed. This paper presents a review of the risk mitigation measures that were implemented to reduce risks to people and equipment working in the area.

Feb 23, 2014

By James L. Hendrix

This paper is intended to give the reader an update on the work being done at the Mackay School of Mines about the fate of cyanide on precious metals mill tailings waste. During the last two years several tailings impoundments have been sampled and analyzed for total and free cyanides. From our sampling program we are beginning to learn valuable information concerning the fate of cyanides in precious metals mill wastes. Included in this paper is a detailed description of our sampling and analytical techniques. Also, some of the data obtained from five sites are given.

Jan 1, 1986

By O. W. Kamper

To most of you present here the word "refractories" is not new and you are familiar with the materials and use. To many people though the question is asked, "What are refractoriness and what are they used for?" Refractories are non-metallic products which are so resistant too melting at very high temperatures that they can be used for building or lining furnaces of all kinds. A large variation occurs in the size, form, and composition depending on the service for which they are intended. They are made from a wide variety of raw materials, of which fire clay and quartzite are used in largest quantities. Other refractory raw materials include magnesite, chrome, diaspore, bauxite, kyanite, sillimanite, olivine, zircon, and many others. Most of these are assembled from-widely-'separated points in the United States while others come from the far corners of the earth. Chrome is imported from the Philippines and South Africa, and, to a lesser extent, Turkey and Greece Kyanite and sillimanite come: from India and bauxite from the Guianas. And there's "magnesite from brines," produced in chemical plant's by treatment of sea water or inland deep-well brines with hydrated lime. The proportion of magnesia available in sea water is so small, less than one pound from 500 pounds of water,, that millions of gallons must be pumped and processed each day in a sea water magnesite plant. The realm of refractory raw materials, therefore, is very extensive and continues to grow because of the endeavor to find-better raw materials from which to produce better products for refractory service.

Jan 1, 1960

By F. M. Benavides

The mining complex being analyzed consists of four mines and two processing plants located in an area where there are several existing modes of transportation. Figure 1 shows a map of the general layout of the four proposed mines and the two existing processing plants. The mines are identified by the numerals "I" through "IV" and the plants by the letters "A" and "B". A proposed overland conveyor would collect the product from all four mines and convey it to Processing Plant A. Alternate transportation systems are as follows: Railroad transport from Mines I and II to Plant B; Highway trucking from Mines I and II to Plant A; Off-the-road truck haulage from Mine III to Plant B and from Mine IV to Plant A. River transportation from the mines to the processing plants was not considered in this study under the assumption that the high capital investments for the loading and unloading facilities, in addition to difficult traffic problems, would make this mode of transportation unattractive.

Jan 1, 1980

By Prescott Greene

AVAILABLE MACHINES Machines discussed in this section include only rubber tire mounted kerf cutting machines of a self¬propelled electrically powered design. Such machines handle bars up to 4.6 m (15 ft) in length, cutting kerfs of from 115 to 191 mm (4.5 to 7.5 in.). The basic design concept of all machines currently in production is very similar. The chassis features dual driving wheels on the cutter-bar end, fixed directly to the main frame. The steering wheels on the outby end of the frame are articulated in some manner to keep all four wheels on the floor over uneven bottom. Machine power for tramming, and all other functions except powering the cutting chain, is furnished from a pump motor that drives the specific pump or pumps required by a given machine. The cutter chain is driven through a mechanical drive train from a separate electric motor having no duty other than driving the chain. The general arrangement of a cutting machine is shown in Fig. 1; two types of machines, with their specifications are shown in Figs. 2 through 5. A hydraulically powered cable normally is included to eliminate the need for manual cable handling and make this a one-man machine. A bug duster, though optional, is needed for most applications. The bug duster is an hydraulically driven scroll conveyor located directly behind the cutter chain drive sprocket. Its function is to move the cuttings away from the sprocket to prevent them from packing up in this area and consuming a lot of machine power to further pulverize them. Available machines vary from models 610 mm (24 in.) high that can cut horizontally only from 203 mm (8 in.) below ground line to 229 mm (9 in.) above, to machines 1143 mm (45 in.) high that can cut in any plane from 178 mm (7 in.) below the ground line to 3.7 m (12 ft) above it. Most currently manufactured machines fall in the 17 200 to 20 400 kg (38,000 to 45,000 lb) weight range, but can be dis¬assembled for underground installation where weight and size are a problem. Maximum teardown results in all pieces having a weight of 5400 kg (12,000 lb) or less and a size allowing passage through a 1.2 x 2.1-m (4x7-ft) opening. Further reduction in either size or weight of the parts becomes a serious problem. Machines currently being manufactured are avail¬able for use with power supplies of 250 v dc; 500 v dc; 440, 550, or 950 v ac (60 Hz). Also available are machines for use on 415, 500, and 950 v 50 Hz. De¬signs to allow operation on other voltages of either 50 or 60 Hz can be made available without any serious problems. As of September 1977, a typical medium-seam ma¬chine without the extra options needed for unusual conditions, but fully equipped to operate, was selling for about $185,000. CAPABILITIES Materials That Can Be Cut The problem of deciding before a machine is put on the job whether it can work effectively is an old one that has never been completely solved and probably

Jan 1, 1982

By E. L. Piper

Natural graphite has been known for many centuries, having first been reported as a distinct mineral form by Gessner in 1565. At that time, graphite was used extensively as pencil "lead" because of the ease with which it marks paper. It is a black, unctuous material found as flakes, lumps, or needles in scattered locations throughout the world. The less crystalline, or "amorphous", natural graphites are thought to have been formed from coal under conditions of high temperature and pressure. The more crystalline varieties, such as those mined in Ceylon, probably were precipitated from molten solutions or were pyrolyzed from gaseous carbon compounds. Recognition of the good thermal and electrical conductivity of graphite, together with its highly refractory nature, led to an increasing number of appli¬cations for this material. Clay and pitch bonded natural graphite has been used in crucibles, refractories, foundry facings, and other high-temperature appli¬cations. These forms constitute the most important current uses for natural graphite in the United States. Other products containing natural graphite include batteries, lubricants, pencils, brake linings, etc.

Jan 1, 1973

By A. R. Negele

Kaolin-based pigments are the most widely used pigments in the paper industry. Several types are available and include standard hydrous, delaminated, calcined, chemically-structured, and most recently, composite pigments. Within each category, a spectrum of products is available to satisfy the application requirements of paper producers. The paper industry has a broad range of applications including fillers in woodfree and groundwood-containing papers, pigmented size press applications, ultra-lightweight and lightweight coated papers, coated merchant papers, cast coated papers and coated paperboard. Each application has its own set of performance criteria and suppliers must work with mills to identify appropriate product(s) to fulfill these requirements.

Jan 1, 1993

By S. R. Titley

Results of regional analyses of precious metal habits in Arizona ores lead to interpretations of a fundamental ore control related to geographic location that corresponds with crustal contrasts. Measurements of isotopic and trace element characteristics of Laramide ore-related intrusions lead to interpretations of crustal derivation of apparent ore-related magmas. Interpreted regionally, the numerous kinds of Laramide ores, which include porphyry copper deposits of this southern cordilleran region appear to be phenomena of a specific crustal lithology characterized by a basement of Proterozoic turbidites and (an interpreted) lower crust of amphibolite. This association with a specific basement terrane may be extended in principle from the United states into Mexico where faulted offsets of this basement are similarly favorable to formation of Laramide porphyry ores -to the exclusion of adjacent terranes. Whereas plate tectonic mechanisms may have triggered evolution of these ores, it is hypothesized here that crustal setting and crustal composition are more profound influences of metallogenesis.

Jan 1, 1992

By R. Mensah-Biney

The adsorption of gold-thiourea complex onto a cation exchange resin, Amberlite 252, has been evaluated in a batch stirred reactor. The observed non equilibrium saturation capacity was 3.20 meg Au/g dry resin (620 kg/t) whereas the equilibrium ion exchange capacity was only 0.53 meq/g (103 kg/t). The enthalpy of adsorption was 4 -25 kJ/mole under equilibrium conditions and increased to 20-200 kJ/mole under non equilibrium conditions. Under non equilibrium conditions, the adsorption capacity of the resin decreased with increasing temperature and increasing thiourea concentration and increased with increasing gold concentration. This dependence of adsorption capacity on thiourea concentration and temperature may be a useful tool for elution of gold from the loaded resin. Scanning electron microscopy revealed evidence of deposition of elemental gold on the loaded resin under non equilibrium conditions. The proposed mechanism for "adsorption" of gold-thiourea complex onto this cation exchange resin consists of an ion exchange reaction followed by a reduction of the exchanged gold complex to elemental gold on the surface of the resin.

Jan 1, 1997

By M. R. Yalamanchili

Recently, noequilbrium electrokinetic measurements using laser-Doppler electrophoresis were reported by Miller et al. (1992) for alkali halides and the sign of their surface charge thus determined. These results are generally as expected from simplified lattice ion hydration theory with KCI, under normal circumstances, being the most significant exception. In this regard, lattice defects (F centers and oxygen imperfections) have been found to influence the surface charge of KCI and its electrophoretic mobility. In particular, the presence of oxygen defect states in the crystal lattice has been found to be responsible for KCI's unexpected behavior. The concentration of oxygen defect states in KCI, as characterized by UV/Vis absorption, was varied in order to study their influence on the electrokinetic behavior and subsequently on the flotation response of KCl. At low oxygen contents « 60 ppm) KCI is positively charged as expected from lattice ion hydration theory. However, typically, KCI contains substantial oxygen (>300 ppm) sufficient to impart a negative surface charge which accounts for the selective flotation of KCI from NaCl by hetero-coagulation with oppositely charged alkyl amine hydrochloride collector colloids.

Jan 1, 1994

By J. A. Organiscak

Two types of airflow splitting methods for improving longwall dust control were investigated by NIOSH's Pittsburgh Research Laboratory. These methods included a translucent mesh barrier and a staged spray barrier system to confine the shearer-generated dust to the coal extraction side of the long wall face while maintaining a cleaner split of airflow on the opposing worker walkway side of the longwall face. The translucent mesh barrier was shown to provide notable dust control effectiveness up to 60 m downstream of the shearer in both the laboratory experiments and a long wall field evaluation, provided the mesh barrier remains relatively parallel to the airflow. The staged spray barrier system showed marginal dust control effectiveness in the laboratory and subsequently was not field tested.

Jan 1, 1999

By W. E. Benton

Diatomite or diatomaceous earth is a siliceous sedimentary rock principally made up of the skeletal remains of the diatom, a microscopic, single-cell aquatic plant related to algae. The unique structure, chemical stability and physical properties are the major attributes of diatomite not met by other forms of silica. The production of diatomite was down in 1982 vs. 1981, reflecting the worldwide recession. The principal markets for diatomite products continue to be basically filtration and fillers. The outlook is for small but steady growth into the 1990s.

Jan 1, 1983

By Daniel A. Wasson

A review of the history of boosters is given with examples of the prominent types that have been made commercially. The performance and design features of protected core boosters are discussed in detail. A new gel booster is discussed with its advantages to the mining industry. Booster size, hole configuration, performance and safety aspects are reviewed. Important features of boostering in above ground and underground blasting are related to an economic analysis. This presentation will cover different types of boosters commonly used in mining. However, for the purpose of this paper a few terms need to be defined to clarify the action of different parts of a priming system. Booster* - "Any unit of explosive or blasting agent to be used in a charged hole for the purpose of perpetuating or intensifying the initial detonation". Primer* - "A unit, package or cartridge' of explosives containing a detonator or detonating cord which is used to transmit detonation to other explosives or blasting agents". Detonator - A device for initiating a detonation from a flame or a small electric current, the former being represented by a fuse cap and the latter an electric blasting cap.

Jan 1, 1981

By E. J. Wade

My subject is gold price forecasting and monitoring as an important aspect of gold marketing. While I 'm specifically addressing gold, it is understandable that many other commodities could be readily substituted. Gold marketing must be studied as three distinct processes, and it is my intention to cover each of these processes in turn. First I?ll cover the process of gold price monitoring and forecasting in some detail. In order to select a method, or combination of methods, to be used to sell gold a determination of the future price profile is essential. The profitability of the sales effort will be determined, to a large extent, by how accurately the future price behavior of the gold market has been forecast.

Jan 1, 1985

By C. Hanson

Two modes of potential loss of oxime extractants in liquid extraction processes for the extraction of copper have been studied. In loss "by chemical degradation, two mechanisms of acid hydrolysis are possible, some reagents degrade primarily in the organic bulk phase, Others at the interface between the organic phase-- phase protects the oxime but salts added to the aqueous acid phase can promote the rate of degradation. The reagents reported on are the LIX series (Henkel Cpn), SME529 (Shell Chem.Co.) and P5100 (Acorga) Loss by organic entrainment in the aqueous phase leaving mixer-settlers has also been studied, parameters investigated including impeller/tank geometry and the phase inlet arrangements. The consequences of extractant loss by the above mechanisms...are commented upon. They include the direct economic cost, the possible environmental problems and the implications for downstream operations such, as electrowinning.

Jan 1, 1980