Search Documents

By Iván Ibañez

An essential aspect of energy efficiency is determining the opportunities to improve a system or machine's performance from the energetic point of view. For the mining industry, it's a classic problem that mainly all the equipment manufacturers face today to produce the same results with the minimum energy requirements. Existing research focuses on light-duty vehicle energy losses. However, heavy-duty off-road machinery is understudied. This article presents an energy balance assessment of a mining vehicle utilized in an open-pit mine in Colombia.

Sep 29, 2023

At a meeting of the Board of Directors, held Jan. 21, 1916, the following resolution was adopted: Resolved, that this Board has learned with indignation and sorrow of the unprovoked and brutal murder of 18 American citizens on January 10, in the State of Chihuahua, Mexico, and laments especially the death of Messrs. C. R. Watson, C. A. Pringle, H. C. Hase, and W. J. Wallace, who were members of the American Institute of Mining Engineers. As these men and their companies were engaged, in the lawful prosecution of their work, we trust that nothing will be allowed to prevent or delay appropriate action by our Government concerning the outrage by which they lost their lives;

Jan 3, 1916

By G. L. Oldright

This paper is the third1 of a series of five papers that is to appear on smelting in the lead blast furnace. The objects of this investigation are to determine the conditions obtaining within the blast furnace be direct experimentation, and to correlate the behavior of the furnace at various times with the main factors governing the operation of the blast furnace, and metallurgical losses. ACKNOWLEDGEMENTS The writers wish to express their appreciation to the management of the international Smelting Company at Tooele, Utah, for their kind cooperation which made possible the assembling of these data.

Jan 1, 1929

By W. Dingley, G. R. Hoey

"AbstractWear of six types of grinding balls was compared with and without corrosion inhibition in grinding Ni-Cu sulphide and hematite ores in laboratory ball mills. Forged steel balls (Rc 60 to 65) and three types of white cast iron balls (Rc 50 to 65) were susceptible to corrosive wear and two types of stainless steel balls [AISI Type 440C (Rc 65) and AISI Type 302 is; 35)] were relatively immune. The relative wear rates of the five types of hard balls (Rc 50 to 65) were dependent on the corrosivity of the ore. Ranking of the hard balls with respect to wear resistance was consistent for the sulphide and hematite ores in the presence of corrosion inhibition, whereas their ranking was different for the two ores in the absence of inhibition.The electrochemical potential of the grinding balls was measured during grinding and was found to be a useful measurement for assessing the susceptibility of an alloy to corrosive wear. Reduction of ball wear for forged steel and white cast irons with corrosion inhibition was concomitant with a shift of ball potential to less active values. Ball potentials in the presence of inhibition were indicative of non-corroding metal surfaces.IntroductionA PREVIOUS STUDY by the authors (1) showed that corrosion inhibitors - sodium nitrite, sodium chromate and sodium metasilicate - reduced wear of forged steel grinding balls by up to 49% in grinding Ni-Cu sulphide ore. Although the mechanism of wear reduction was not elucidated, it was concluded that corrosion must play a significant role in the wear of grinding media. Remark and Wick (2) of Battelle Pacific Northwest Laboratories have also evaluated corrosion inhibitors for the reduction of metal wear using abrasive and n on- abrasive te sting procedures. Their research was sponsored by 16 companies throughout the world. Preliminary results indicated that anodic inhibitors prevent from one-fourth to one-half of the loss due to corrosion."

Jan 1, 1977

By S. J. Aparo

Phosphate mining and beneficiation in the State of Florida are presently being carried on by 12 different mining companies with a total of 21 mining and flotation plant locations. Their combined production of both washer rock and flotation concentrate was approximately 28,000,000 long tons in 1968. This accounted for 70-72% of the total U. S. production and close to 30% of the world's output of this mineral. From this extensive activity in the Florida phosphate field, one basic flow sheet for beneficiation of the ore has developed over the years as the most commonly employed. In fact, all of these plants with the exception of two beneficiate Florida pebble phosphate using a basic operation as illustrated in Figure I. The two plants which differ from this general approach are not using raw matrix as feed. In one instance, +14 mesh pebble is ground in a rod mill to release free silica which is subsequently removed in a cationic froth flotation circuit using an amine acetate blend and kerosene. This technique generally results in a 4-7 BPL unit upgrading of the feed pebble. The other exception to the standard flow sheet illustrated in Figure I is an operation which is beneficiating tailing piles. In this case, the material is first subjected to cationic froth flotation in order to upgrade the feed to a point comparable to normal matrix. Thereafter, after, the phosphate is floated in an anionic rougher circuit followed by cationic flotation of the silica in a cleaner circuit.

Jan 1, 1969

By M. E. Charles

The use of water flowing as a lower layer to reduce pressure gradients in petroleum pipelines was investigated using 17.5 deg. A.P.I. Lloydminster crude oil in a 1-inch laboratory pipe-line and a 21h-inch field pipeline. The method was found to be very effective in reducing the pressure gradient below that for the oil flowing alone. The factor by which the pres-sure gradient was reduced varied with the percentage of water added, and in general exceeded 10 for water contents ranging from 40 to 60 per cent. Within this range of water content the pressure gradient reduction factor was independent of the oil flow rate.

Jan 1, 1960

By William H. Bassett, C. J. Snyder

Cable sheaths made from common lead have been used to protect underground cables since the beginning of the power-cable industry. Only within the last few years, however, has a systematic study of the production methods and of the causes of failures in cable sheathing been undertaken. Recent increases in the use and demands for service made upon power cables have emphasized the importance of high-quality cable sheaths. It was customary for the users to attribute the cause for their sheath failures to the lack of purity of the lead, but this contention has not been borne out by field and laboratory inspection of the sheaths. During the past two years the writers have had an opportunity to examine various types of sheaths that were removed from power cables after failure. These samples were obtained from various parts of the country and represent, it is supposed, the production of the principal cable manufacturers. Aside from corrosion, the common field difficulties can be classified either as mechanical or structural, as outlined below, and when structural irregularities are found they can all be attributed to manufacturing causes and in no way reflect the purity of the lead. Clasxification of Cable Sheath Failures Other Than Corrosive Mechanical Irregularities A. Splits caused by excessive internal pressure B. Injuries such as nail holes, cuts, tsars, etc. C. Intercrystalline cracks caused by vibration Structural Irregularities A. Splits C. Voids in wall of sheath a. Caused by imperfect welds a. Blisters 13. Holes through sheath b. Laminations a. Caused by yellow oxide inclu- D. Questionable structures sions in sheath wall a. Prominent flow lines b. Blowouts by entrapped gases b. Large areas filled with suboxide during manufacture c. Scattered yellow oxide or dirt C. Caused by inclusions of dirt and

Jan 1, 1933

By Linsheng Xu

When coal seam is under the integral thick sandstone (or conglomerate), the structure of thick sandstone is integral and its strength is rather high. After coal is extracted, the roof is hanging and caving is difficult. When the method of full caving is adopted in the longwall working face to control this kind of hard and difficult caving roof, the effect of roof-controlling affects directly the production and safety. In China Datong Coal Mines the extracting coal deposit is Datong Jurassic period. Most of the roof is sandstone and conglomerate. It is hard and difficult to cave. Having used special hydraulic power supports and other special ways to deal with the roof, the hard and difficult caving roof has been controlled.

Jan 1, 1986

By Reed W. Hyde

SOME information has been published on the sulphur dioxide concentration of gases from Dwight-Lloyd machines sintering lead ores but most of this relates to the customary practice in which the charge is relatively high in lead and is sintered in two passes over the machine. It is thought, therefore, that the following observations on sintering in one pass a low-lead, low-sulphur charge may be of interest. The data were obtained in sintering lead sulphide flotation concentrates mixed with minus 20-mesh oxide ore, the mixture carrying 16.8 per cent Pb and 5.3 per cent S. No returns were used because of the limited amount of sulphur available as fuel, but the mixture pelletized readily to make a satisfactorily permeable bed on the sintering machine. As there was a possibility that the SO2 might be utilized, a series of runs was made to determine the concentration of SO2 in the gases at different points along the wind box, and the effect on this concentration of changes in the wind-box vacuum. Several runs each were made with vacuums (as measured in inches of water at the wind box) of (1) 2 to 1 3/4 in., (2) 4 to 3 1/2 in. and (3) 6 to 5 1/8 in. The averages of the determinations from each series are platted on the graph (Fig. I). The vertical scale shows the percentage by volume of SO2 (as determined by the Reich method), and the horizontal scale shows the time expressed as percentage of the total sintering time. Sintering was considered to be complete when no SO2 could be detected in the gases. In all cases the depth of bed was 4 1/2 in. and the weight of dry charge per square foot of hearth area was 45.2 lb. Other data are given in the table. The volume of gases corresponding to the several points along the wind box at which SO2 determinations were made could not be measured, but has been calculated from the SO2 content and sulphur elimination on the assumption that the volume is uniform throughout the sintering period. This is not strictly true, as with a given vacuum the volume will usually drop slightly toward the middle of the period and increase toward the end. However, this assumption is a reasonable approximation. Several interesting features are brought out by these data. In general, the published data on SO2 concentration in sintering under ordinary conditions show a high SO2 concentration in the early stages followed by a rapid decrease in concentration and with relatively little SO2 in the gases from the last half or third of the operation. In other words, the greater part of the sulphur elimination is obtained in the first third or half of the period. In these runs, the 6-in. vacuum, which approximates the usual operating condition, gives a curve that follows this customary pattern. Maximum SO2 concentration is obtained 2 ½ min. after

Jan 1, 1942

By J. P. Burland

The paper describes a number of recent case histories in the United Kingdom where field instrumentation and measurements have played a major role in the design and construction of excavations, piles and foundations. It is shown that the design and construction procedures for deep excavations in London Clay are based almost entirely on the results of field measurements. Examples are given of successful application of such measurements. The present understanding of the behaviour of bored piles in stiff clays and their design is based on a number of instrumented pile loading tests. The results of these tests have led to a radically new concept of pile design in which the piles operate at their full shaft capacity under working loads thereby resulting in considerable savings in design and construction. Some examples of the successful application of this concept are given. Finally it is shown that the present knowledge of the stiffness properties of chalk is based entirely on field observations. An example is given of how direct field measurements were used to solve a foundation problem at the base of a coffer-dam in chalk.

Jan 1, 2010

By A. E. Petersen

To reduce U.S. dependence on imports of titanium, the U.S. Bureau of Mines has investigated the recovery of titanium from perovskite (CaTi03). Domestic perovskite deposits represent a significant, but untapped, titanium resource. An acid sulfation method was developed that will extract about 97 pct of the titanium and the columbium and 70 to 90 pct of the rare-earth byproducts from perovskite concentrates. A flow-sheet for recovering titanium as pigment-grade titanium dioxide (Ti02) is discussed. Test work performed in developing each unit operation is described. The first three unit operations have been demonstrated using laboratory-scale continuous methods of operation: acid sulfation of perovskite concentrates, leaching sulfation residue to dissolve metal values, and precipitation of titanium oxysulfate monohydrate (TiOS04?HP) from the resulting leach flltrate. Batch testing of other unit operations was performed: TiOS04?H20 redissolution and iron reduction, precipitation of Ti02 by hydrolysis, and regenerating recoverable acid with rare-earth byproduct recovery. Cost evaluation results are provided, indicating that processing perovskite concentrates by acid sulfation may be an economically viable means of producing Ti02.

Jan 1, 2010

By S. K. Kawatra, A. K. Bakshi, T. C. Eisele

An on-line rheometer, suitable for use with slurries, has been developed at Michigan Technological University. This rheometer can be used with both Newtonian and non-Newtonian slurries, and produces complete shear-rate/shear stress curves which characterize the time-independent rheology of the slurry. The sensor utilizes the Hagen-Poiseuille equation and Boyle's Law to calculate the shear rate, slurry flowrate, and shear stress from a series of pressure measurements. The design of the unit allows the measurement sample to be continuously collected from operating process streams in the often-hostile on-line environment. The shear rate/shear stress curves can be used to conveniently calculate the apparent viscosity at any given shear rate, and also to measure any yield stress or other deviations from Newtonian behavior.

Jan 1, 1999

By C. Denis Thibodeau

Outline Introduction 402 OB Mining Sequence Trial to Verify Sequence Change Monitoring Observations Numerical Modelling Conclusion

May 1, 2013

By John J. Henn

An economic evaluation was made of the Bureau of Mines incinerator residue separation process to update the one published in 1971 to a mid-1.974 cost basis. This evaluation includes a modification of the glass-recovery operation used In the original plant design as well as a unit to bale the ferrous scrap product before shipment. Products from the plant are ferrous metal, aluminum and copper-zinc scrap, and a mixed-color glass cullet. The estimated capital and operating costs for four plant sizes are as follows : [ ] The operating costs do not include credits for recovered metals and glass.

Jan 1, 1975

By A. Zangooi, J. A. Finch

Flotation is a separation process based on the collection of particles on the surface of bubbles. Flotation machines disperse air into bubbles using a variety of techniques. The characteristics of the bubble population are strongly affected by the selection of frother type and concentration. As metallurgical results depend on the bubble distribution, the measurement of frother concentration is vital to understand and control performance. A previously developed colorimetric technique was refined to work with low solubility frothers and to increase daily analysis rate. Field-testing demonstrated that the method is robust, reliable and accurate. As well as relating frother concentration to gas dispersion measurements, the results can be used to answer operational questions including: how well a frother dissolves, how reliable and stable frother delivery is, how evenly frother is distributed down a bank, and whether frother distributes between the pulp and froth zones. Some of these points are illustrated from plant experiences. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists ofCIM Sudbury, Ontario, Canada Edited by

Jan 1, 2009

By S. K. Murphy, S. M. Spottiswoode, A. M. Milev, D. Geyser

A portable, stand-alone instrument especially designed for recording strong ground motion was used in this study to create a large database of peak particle velocities measured underground. A total number of 39 sites located in stopes mining Carbon Leader and Ventersdorp Contact Reefs were investigated. Peak particle velocities whith values up to 3 m/s were recorded at some sites. The data recorded on the skin of the excavations were compared to the data recorded by the mine seismic networks to determine the site response. The maximum site response was obtained for source radii of between 5 m and 30 m and events locating within 200 m of the site. The extreme values of peak particle velocities were obtained in cases were the face-area lay within the source radius. Un instrument portable unique spécifiquement conçu pour enregistrer les mouvements dynamiques des terrains, a été utilisé dans cette étude pour créer une base de données importante sur la vélocité maximum des particules, mesurée en souterrain. Un nombre total de 39 sites situés dans les excavations exploitant les récifs appelés ‘Carbon Leader et Ventersdorp Contact Reefs’, a été investigué. Une vélocité maximale avec des valeurs allant jusqu’ à 3 m/s a été enregistrée sur certains sites. Les données enregistrées sur le bord de l’excavation ont été comparées aux données enregistrées par les réseaux séismiques de la mine pour déterminer la réponse du site. La réponse maximum du site a été obtenue pour des sources de rayons entre 5 m et 30 m et des évènements situés dans les 200 m du site. Les valeurs extrêmes de vélocités maximales ont été obtenues pour les cas où la zone de face se trouve à l’intérieur du rayon de la source. Ein mobiles, alleinstehendes Instrument, speziell entworfen um starke Formationsbewegungen aufzuzeichnen, wurde in dieser Studie verwendet um eine große Datenbank von Partikelspitzengeschwindigkeiten, die Untertage gemessen wurden, aufzuzeichnen. Eine Gesamtanzahl von 39 Aufstellungsorten in den Schichtabbauorten vom Carbon Leader und Ventersdorp Contact Reef wurden untersucht. Partikelspitzengeschwindigkeiten mit Werten bis zu 3 m/s wurden an einigen Standorten aufgezeichnet Die an der Oberfläche des Grubenraumes aufgezeichneten Daten wurden mit jenen Daten verglichen, die vom seismischen Netzwerk der Grube notiert wurden, um die örtliche Reaktion des Standortes zu bestimmen. Die maximale Standortreaktion wurde für Ursprungsradien von zwischen 5 m und 30 m erhalten und Ereignissen die sich innerhalb von 200 m vom Standort befanden. Die extremen Werte der Partikelhöchstgeschwindigkeiten wurdenin jenen Fällen erreicht wo sich der Abbaubereich innerhalb des Ursprungsradiuses befand.

Jan 1, 2003

By T. R. Ellis

Many appraisers/valuers believe that the only valuation method available within the cost approach category for real property appraisal is the depreciated replacement cost method. Some valuation and financial reporting standards setters also believe the same. This paper introduces the minerals appraiser to a number of useful methods for mineral property appraisal that are based primarily on the principle of contribution to value, the predominant economic principle in the cost approach. Most of these cost approach methods discussed are primarily for use in valuation of exploration tracts and resource properties that have no defined reserves. However, the powerful rural cost method can be used to calculate the contribution of categories of resources, reserves and other property components to the value of a mineral property. This method can be applied to mineral properties at all stages of development, including producing properties. The author reasons that standards and regulations pertaining to real property valuation should be modified, and underlying principles should be expanded, so as not to inhibit appropriate application of these cost approach methods.

Jan 1, 2011

Two new inorganic-organic hybrid polymers, Al(OH)3-polyacrylamide (Al(OH)3-PAM) and Mg(OH)2-polyacrylamide (Mg(OH)2-PAM) were synthesized and successfully applied for the treatment of oil sand tailings. The results indicate that both Mg(OH)2-PAM and Al(OH)3-PAM were unaffected by the change in pH, and could be applied to oil sand tailings with varying sand-to-fine ratio (SFR). The optimum dosages for the Mg(OH)2-PAM and Al(OH)3-PAM were about 330 g/ton and 650 g/ton, respectively for SFR 3.75. The flocculated oil sand tailings dewater quickly producing 66-68% solids. The flocculated tailings produced similar filtration rate before and after shear. Mg(OH)2-PAM treated oil sand tailings produced twice the filtration rates (220 ml/min) compared with Al(OH)3-PAM. This study clearly indicates that Mg(OH)2-PAM and Al(OH)3-PAM is a viable solution while decreasing the mass-production of tailings and increasing the rate of water-recycle.

Jan 1, 2012

By Manuel Viveros J.

This paper will deal with the type of rocks so called evaporites, which are sedimentary rocks produced by water evaporation from seas, lakes or marginal lagoons, in warm and arid climates. Salts derived from these deposits are precipitated according to their solubility; that is, the more soluble precipitates first, overlain by other sediments like silts, shales, limestones, sands, etc. The most common evaporites, according to their chemical composition, are : Chlorides Sulphates Carbonates Nitrates Borates Common salt, or halite, sulphates like anhydrite and gypsum, are the most important. Potassium chloride (silvite and carnalite) and potassium sulphate are of great commercial value.

Jan 1, 1974

By Edgar T. Gregory

A quiet revolution has taken place in the conveyor belt industry, Man-made materials, improved production facilities, better splicing techniques and emphasis on repair and maintenance have all contributed substantially to lowering material handling costs for the mining industry, It wasn't too many years ago that the rubber industry had only cotton for a belt carcass and tree grown rubber for the protective cover. Then came the development of monofilament rayon. This material had desirable elongation and elastic properties and was the first synthetic fiber to be used in place of cotton. But wet strength and other limitations restricted its use, and the conveyor belt industry turned to nylon. Initially, nylon was considered suitable only for the cross threads or filler threads of a belt carcass. Then technical advancements in heat setting and fabric weave created a major change in belt construction. As a result of these advances the industry was able to take advantage of the full tension strength of nylon cord. Another breakthrough in the use of synthetics was the tremendous increase in adhesion resulting from a chemical bond, rather than the limited physical bond available with cotton. But the advantages of nylon had a more Car-reaching effect, We were able to design a two-ply nylon belt that did the work of a four- or five-ply cotton or rayon belt. A six-ply nylon belt now replaces a twelve-ply cotton elevator belt. Arid nylon resists moisture, acid and mildew, It also has excellent resistance to impact and can be produced with controlled elongation and elastic properties that work to great advantage in reduced-ply belt constructions.

Jan 1, 1971