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By D. Harrington

Probably over 95 percent of the coal production of the United States depends upon the use of explosives before it can be placed in the railroad car at the mine, and up to the present time it has been impossible to obtain Pry kind of practicable explosive that isn't dangerous unless handled carefully. In other words, no "foolproof" explosives have been found to date and inspection of the accident records of the coal mines of this country indicates that the use of explosives in coal mines has taken a sad toll of lives. ACCIDENTS PROM EXPLOSIVES IN COAL MATES Of the 2,000 to 2,500 persons killed annually in the coal mines if the United States, 100 to 125 have been killed from explosives without an explosion of gas or dust; these accidents have been due to misfires, hangfires, premature blasts, or accidental setting off of explosives through carelessness or otherwise (but chiefly through carelessness in some form). In this type of accident the flame character of the explosive is not necessarily involved, although an unexpected or premature blast is initiated much more easily with black blasting powder, which has a long flame, than with a permissible explosive, which has a flame much shorter and of briefer duration. By far the greater number of such accidents are caused by black blasting powder or dynamite rather than by permissible explosive.

Jan 1, 1936

If one can embrace the medical analogue, much of the mining industry currently suffers from a massive bacterial infection. When pyrite-bearing or sulfide-bearing rock formations, tailings, or mine wastes are infected by Acidithiobacillus ferro-oxidans, the likelihood of forming acid rock drainage (ARD) is almost guaranteed. The ?pharmacy? of antibiotics available is extensive, ranging from solid alkaline amendments like limestone to liquid ?medicines? such as sodium lauryl sulfate, sodium thiocyanate, waste milk, and bipolar lipids. Unfortunately, the ?geo-medical? teams of geochemists, microbiologists, engineers, and mine managers lack the tools to surgically apply these active ingredients where they are needed most with a minimum of waste. Distribution of fine grained limestone on the surface of an acidic mine waste dump is analogous to applying a bandage soaked in antacid to treat an upset stomach. The implementation of up-to-date best management practices has not healed the patient; an equivalent combination of hypodermic needle, cyber knife, and arthroscopic probe is clearly needed. Using an engineered, flow-able or pumpable foam or pHoam? as the medicinally analogous ?dextrose delivery solution? for solid and/or liquid ?geo-antibiotics?, the authors have combined off-the-shelf technologies that have been previously applied in solving geotechnical problems in the mining industry. A patent for the innovative process is pending. This paper discusses method concepts and the advantages it could provide over conventional BMPs.

Jan 1, 2012

By P. J. Hancox

Heavy mineral deposits have been known from Liberia since the1950s from both river and beach placers. The heavy mineral content of beach sands ranges between 28?62% and the suite includes ilmenite, rutile, zircon and magnetite. These occur together with kyanite, sillimanite, staurolite and garnet. The average ilmenite content is 82% with minor zircon (11%), rutile (6%) and monazite (1%). The ilmenite is, however, of poor quality with haematite intergrowths and a titanium content ranging from10?42.4% (average ±25% TiO2). The amounts of rutile and zircon, while of suitable quality, have also previously been deemed too low for economic exploitation.

Jan 1, 2000

AMONG the multifarious duties which fall to the lot of a mining engineer it is safe to say that there is none of more fundamental importance than the study of the ore-deposits on which it is thefunction of his profession to operate, inasmuch as the whole business of mining in all its complicated ramifications rests first of all on the existence of something to mine. -When the ore supplies in a mine fail, the enterprise comes to- an end, and nothing, therefore, is of more importance than a thorough understanding of the conditions under which the ore occurs, so that everything possible may be done to open up the mines well ahead of their immediate output requirements, and develop new ore reserves to take the place of that which is raised from day to day. The great aim which the mining engineer has to keep before him in his study of his ore-deposits is to obtain such a knowledge of them that he will have sound grounds for prediction as to how they will behave in parts of the mines which are well beyond the point of the pick. It is on his judgment of probabilities in this respect that mining operations are entered upon, and the more thorough his knowledge of all the factors affecting the problem, the more is the judgmentlikely to be a sound one. The test of any theory is experimental confirmation of the truth of predictions based upon it, and our aim should be to try to perfect our knowledge of the rules governing deposition of ores, so that our theories may prove themselves equal to the task of successful prediction.

Jan 1, 1909

By T. S. Heah, S. T. Bishop

"The Lorraine property is located in the northern Intermontane Belt, north-central British Columbia. The property is underlain by intrusive rocks of the Duckling Creek Syenite Complex, an Early Jurassic, alkaline phase of the Late Triassic-Early Cretaceous Hogem Batholith. Two significant zones of copper-gold mineralization have been explored to date; the Main zone (historical Upper and Lower deposits) and the recently discovered Extension zone. A combined geological resource was estimated in 1975 for the Main zone deposits at 10 million tonnes averaging 0.7% Cu, and from 0.1 g/t Au to 0.34 g/t Au. The Extension zone, still at an exploration stage, is estimated to be considerably smaller than the Main zone.Copper-gold mineralization at Lorraine Mountain exhibits characteristics suggestive of both magmatic and hydrothermal origins, and may be related to orthomagmatic-hydrothermal fluid flow contemporaneous with magmatism and development of migmatitic fabrics. A depth greater than the depth of formation of classical porphyries may explain many of the variations displayed by mineralization at Lorraine. These characteristics distinguish Lorraine from other members of the alkalic suite of porphyry Cu-Au deposits in the Canadian Cordillera.IntroductionThe Lorraine prospect is located in the Omineca Mountains, at the headwaters of Duckling Creek, 56 km northwest of Germansen Landing (Fig. 1). The property is centred at latitude 55°55'N, longitude l25°26'W on NTS mapsheet 93N/14W. The area is typified by mountains of moderate relief, with elevations ranging from 1150 m in the valleys to peaks of 2000 m. Valleys are U-shaped and blanketed by glacial till which give way to steep, talus covered slopes and sharp ridges. Outcrop is generally limited to elevations above 1600 m (Fig. 2)."

Jan 1, 1995

By S. J. Frank

Ferroalloy furnaces are well known to be extremely difficult to control from a metallurgical perspective. Mostly metallurgical control is still reactive in nature, causing a significant amount of reworking and product blending to achieve a proper product specification. Despite numerous efforts towards the model based control of primary smelting operations, actual metallurgical feed forward control seems to remain elusive. One of the key reasons in the failure to model these metallurgical reactors well, is that fundamentally orientated pyrometallurgists, statisticians, data miners and control engineers very often have diverging ideas how to model these systems. Furthermore, metallurgists have often come to rely on their ability to develop empirical regression models of furnace behaviour, as they have lost their faith in the ability of thermochemical and metallurgical engineering fundamentals to accurately predict the outcomes from furnaces. This paper shows how good thermochemical modelling can be combined with proper technological and systems analysis, as well as a proper inventory model, to predict the alloy and slag chemistry with good accuracy one tap into the future, at a time horizon of typically around 4 to 6 hours. For this modelling approach, a number of tools will be used, such as data reconciliation, thermodynamic modelling using Fact Sage®, inventory and heel estimation, neural networks and statistical data exploration. Furthermore, systems identification theory will be combined with the approaches given above to develop a truly dynamic predictive model. This paper seeks to demonstrate the need for a hybrid approach, which incorporates plant data and readily accessible thermodynamic data to develop a proper dynamic model.

Jan 1, 2004

ON mineral lease 38 of the Sulphide Corporation Limited, Broken Hill, a shaft was sunk in the early days Ior prospecting purposes and at the present time it is accessible as far as the 1000-ft. level where a connexion exists with the main workings of the Corporation's Central Mine, mineral lease 9. About the year 1895· a crosscut was driven east from this shaft at the 1330-ft. level cutting the Central Ore-body in mineral lease 9 and the shaft is supposed to extend a further depth of 25 ft; but no records of any of this work are in existence, the whole of the evidence being based on hearsay and memory:Fig. 1 shows the position of the Extended shaft in relation to the main workings. The shaft filled with water to the 1000-ft. level where it overflowed through the crosscut to the main shaft and was pumped to the surface, but when the South drive on the 1300-ft. level was pushed to the southern boundary, it was deemed advisable for safety, to tap the water at this level and so relieve the...

Jan 1, 1919

By Kul Bhushan

This paper presents the results of lateral load tests on 0.61-m to 1.27-m (24 to 50-inch) diameter drilled and cast-in-place piers in San Diego area residual/formational soils. The test piers were installed and tested in the following soils: Decomposed Granitic Rock (Ktd), Stadium Conglomerate (Tst), and Friars Formation (Tf). Lateral loads of up to 845 KN (190 kip) were applied to the piers in residual granitic soils, and loads up to 1780 KN (400 kip) were applied to the piers in Stadium Conglomerate and Friars Formation. The tests were conducted by jacking against adjacent piers and monitoring the lateral load and lateral deflection at the ground line. Test results indicate that ultimate lateral pile capacities of up to 1800 KN (400 kip) can be obtained for 0.61 m (24-inch) drilled piers with penetration of 3 to 6 m (10 to 20 ft) in the residual/formational soils tested. Lateral load analyses using p-y curves for very dense sand significantly overestimate the observed lateral deflections. For lateral load analyses using dense sand p-y curves, p-multipliers that increase the lateral soil stiffness (p-y curves) by 2 to 8 times are required to match the load-deflection behavior measured in the test piles. When applied to the dense sand p-y curves, the p-multipliers provide a more accurate prediction of load-deflection behavior in the residual/formational soils, and can result in shorter required pier penetration and significant savings in foundation cost.

Jan 1, 2002

By C. Ringas

Pipelines are used extensively in industry to convey various products. Internal corrosion of pipelines can lead to perforation and leakage of the product. A growing problem, not often accurately recognized, is internal corrosion of pipelines caused by bacteria. Microbiologically-induced corrosion (MIC) refers to corrosion caused by a variety of micro-organisms. This form of corrosion is not widely recognized in many industries, although it is widespread and causes many corrosion problems in pipelines, both internal and external. Sulphate-reducing bacteria (SRB) are responsible for the bulk of the corrosion problems caused by MIC. Corrosion caused by SRB is found extensively in water pipelines conveying raw, potable and waste water, as well as in pipelines conveying slurries. This problem also occurs in pipelines conveying crude oil. This paper describes internal corrosion problems of slurry pipelines caused by bacteria and outlines mitigation methods to improve slurry pipeline integrity, thereby extending the life of such pipeline

Jan 1, 2007

High Pressure Grinding Rolls Scale-Up and Experiences

Sep 13, 2010

By A. Pratt

Portland cement is primarily used to solidify backfill in underground mine workings and it represents a major cost in mining operations. CANMET-MMSL has invented an alternative binder technology that does not contain any amount of Portland cement and is made using waste materials, such as development rock and smelter slag. The technology has been successfully tested with many types of base metal and ferrous slag. Research conducted in collaboration with several mining operations in Canada has shown that the CANMET-MMSL binder has considerable potential as a replacement for Portland cement in mine backfill. An integral part of the overall mining operation, backfill is used for two main purposes: safety and environmental remediation. Depending on the mining method used, backfill provides a working surface, stabilizes stope and pillar walls, as well as the surrounding rock mass, and controls caving of stope backs. There are several benefits associated with the replacement of Portland cement in backfill, including reductions in (i) the footprint by placement of slag waste underground, (ii) the environmental effects and long term liability resulting from disposal and containment of slag waste on surface such as acid rock drainage, (iii) GHG as a result of reduced Portland cement usage (the production of 1 ton of Portland cement produces 1 ton of GHG), and (iv) the significant costs associated with reduced Portland cement usage.

May 1, 2010

By K. Najim, D. Hodouin

"The raw ores which are processed in mineral processing plants exhibit very strong variations of their physical and chemical properties. As a consequence, the performances of the comminution and separation processes vary greatly from time to time. Model-based control strategies improve the performance of the plant; however, they require some form of adaptation to cope with the variations of the are properties.This paper deals with the use of adaptive techniques for the control of mineral processes. It begins with a survey on adaptive control algorithms including parameters estimation aspects. Then several examples dealing with crushing, rod, ball, autogenous and semi-autogenous grinding, flotation , drying and calcination processes are reviewed.IntroductionThe operation of the various processes of mineral processing plants (crushing, grinding, flotation, dewatering, etc.) is generally controlled using empirically tuned regulators of constant structure, such as PID controllers. To improve the operation performance, mineral processors try to implement specifically designed controllers, i.e. controllers based on plant dynamic models. Most of the time, these techniques improve the control of the mineral processing installations. However, modelling is a complex procedure because of the problems of measurement and data management, specific to this industry, and because of the variations of the model parameters. In this context model-based control strategies do not always bring the expected improvements or are sometimes discarded and replaced by more conventional techniques .The sources of variation of the dynamic behaviour of mineral processing systems can be classified into three categories: (I) the inherent changes of the raw ore properties (composition, grindability, mineralogical texture, etc.); (2) the process tuning modifications (grinding media loads, number of hydrocyclones, slurry level in flotation cells, agitation speeds, etc.); (3) the feedrate variation of the ore, water, chemical reagents, etc. All these factors change the fundamental properties of the process dynamics such as the grinding or flotation rates and the residence time in the equipment. The simplified linear models which are used to describe the process dynamics are not able to track the complex behaviour of the mineral processing systems when the amplitude of the sources of variation are too large. The mismatch between the model and the plant behaviour is then frequently a cause of model-based controller failures."

Jan 1, 1992

By P. J. Rowsell, M. D. Waller

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993. The applications of artificial intelligence systems in the upstream petroleum industry are reviewed. Particular emphasis is placed on current and potential applications in drilling engineering. Several recent advances in drilling technology have led to a large increase in the quality and volume of data available. This combined with the escalating cost, particularly of off-shore operations, is testing the traditional reliance on the skill and judgement of rig operators. AI systems offer enormous scope in enhancing and aiding the performance of these operations

Apr 1, 1994

Jan 1, 1967

By R. Poisel, C. Scavia, Preh A., W. Roth, M. Pirulli

ABSTRACT: Two methodologies for the three-dimensional simulation of the run out of rock avalanches are presented: one based on a granular approach and the other based on a continuum equivalent approach. An evaluation of the possible run out area of the Oselitzenbach landslide (Carnic Alps, Austria) has been carried out applying the two methodologies. The combined use of these two approaches makes it possible a comprehensive assessment of the run out area. RESUME: Deux méthodologies pour la simulation tridimensionnelle de la propagation des avalanches rocheuses sont présentées: la première est basée sur un modèle de type granulaire et la deuxième sur un modèle du continu équivalent. Une évaluation de la propagation éventuelle de l’avalanche de Oselitzenbach (Alpes Carniche, Autriche) a été réalisée en utilisant les deux méthodologies. Les résultats obtenus montrent que la combinaison des deux approches rend possible une analyse plus complète de la phase de propagation. KURZFASSUNG: Für die dreidimensionale Modellierung eines Felsmassensturzes (sturzstrom) werden zwei Methoden, eine granulare und eine kontinuumsmechanische Methode, vorgestellt. Beide Methoden wurden zur Abschätzung der Ausbreitung (runout) der Massenbewegung Oselitzenbach (Karnische Alpen, Österreich) herangezogen. Die kombinierte Anwendung beider Methoden ermöglichte eine umfassende Beurteilung des möglichen Ausbreitungsbereichs.

Jan 1, 2003

By Hae-Moon Choi, Sang-Don Lee, Chang-Ha Ryu

The purpose of the study presented in this article is to establish a standard blast pattern to yield optimum blasting performance along with an attempt to reduce a difference between design and construction. A series of test blasts were carried out at two tunneling sites of Central Inland Highway crossing in Korea. Long-hole blasting was tested in rock mass whose RMR value is over 60.The blasting results were evaluated by measuring degree of fragmentation, advance rate,muckpile distribution, overbreak, etc. Based on the results of test blast, several patterns were proposed for a two-lane highway tunnel.

Jan 1, 2006

By A. J. Forney

The hot-gas-recycle process, for the hydrogenation of carbon monoxide, was investigated in a 12-inch-diameter reactor. Initially because the distribution of gas was poor, hotspots developed in the catalyst bed. After the velocity profile of the gas flowing through the bed was studied, the method of packing the catalyst was altered. Because this change improved the distribution of gas, temperature control was excellent. The l2-inch-diameter reactor was operated successfully in the synthesis of gaseous and liquid fuels. When high-Btu gas was synthesized in two stages, parallel-plate assemblies of Raney nickel were almost as active as granular Raney nickel in the second reactor. The pressure drop through the second reactor, however, was reduced 90 percent by the use of these assemblies.

Jan 1, 1962

GOLD has played a part in the development of Australia. The total yield exceeds SIX hundred million pounds sterling, while the glamour of gold-mining and the unfailing demand for the product have enhanced its influence. The production is still considerable, but the yield is less than one-quarter of that twenty years previously, while the number of men employed has dropped from 70,000 to 11,000. Not only has there been a marked decline in production, but it is anticipated that thisdecline will continue, and continue more markedly. It is therefore desirable to ascertain the causes of the decline and inquire into means for diminishing or preventing it.The problem under discussion is far from being only local. Finlay states: The grand feature of the history of the business has been the progress of an economic cycle unfavourable to gold milling. The USA yield fell from $101,000,000 to $44,000,000.South Afriea has for some time produced one-half of the world's gold; yet in the Mining and Scientific Press of 11th February, IH22, General Smuts is quoted as saying that if the premium disappeared entirely 24 out of 34 mines would shut down. The solution, however, might be either general eg, a great advance in the metallurgy of gold; or local eg, a bonus; but before discussing any of the proposed solutions it will be advantageous to review the situation.STATISTICS OF THE PAST AND PRESENT PRODUCTION OF THE WORLD AND OF AUSTRALIAThe inquirer soon finds that there is a good deal of uncertainty, and that much care is needed in collating figures. In some cases a considerable part of the output is not officially reported, and returns...

Jan 1, 1924

By Jack Magtoto, Lysa Voight, Tom Martin, John Forero

SUMMARY Commitment by all parties to partnering goals established early in the contract aided Affholder, Inc. in constructing 2,360m (7,700') of soft ground tunnel in Rancho Cordova, CA. Despite two zones of known contamination, encountering a zone of loose cobbles and boulders in a matrix of flowing sand, some perched water tables and a flooded tunnel after 2 upstream safety plugs failed, the Contractor finished the work 33 days early and only 1.91% over his original bid.

Jan 1, 2007

How did you get into mining; were you from a mining town or mining family? Not at all. I grew up in northwest Kansas. I liked to hunt and fish, so I thought it would be fun to work for a company that made knives or guns. It seemed like metallurgical engineers would be something those companies could use, so I started in physical metallurgy. I got a summer job at the great Climax molybdenum mine near Leadville, CO shoveling muck onto conveyors. I was hooked. I loved everything about mining, so in the fall, I changed majors from physical metallurgy to mineral processing. For many years you actually discouraged young people from studying the mining disciplines. Could that be right? That’s true.

Jan 1, 2007