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By Cadwallader Evans

MY endeavor in this paper will be to tell something of the accomplishments and current problems of the anthracite producer and to suggest some of the avenues for technical development that seem to me to be the most necessary and likely to bear fruitful results. The several subjects, that I find of most interest will be taken up individually with brief reference to the future trend. Underground Mining and Loading ?In this field great progress has been made in the last twenty years, beginning with the introduction of the scraper system. The electrical hoists for the operation of scrapers have been improved, and give little trouble, but there is an open field for the improvement of the auxiliary apparatus, particularly in the application of roller-hearing sheaves to the guiding of scraper ropes. Also notable in the last six or seven years is the introduction of shaker chutes, so that far more anthracite is now loaded over them than by scrapers. This trend should continue to be manifest, particularly if those who are looking ahead and who are charged with the development of this specialty continue constantly to study and improve the mechanical design of their shakers.

Jan 1, 1938

By Leonard Obert, Wilbur Duvall

"INTRODUCTION 'The investigation reported herein is part of a comprehensive research program being conducted by the Metal Mining Research Section, Mining Division, Bureau of Mines, on pressure problems in underground mines. This program was initiated in 1937 and for the first 3 years was concerned primarily with measurement of the pressure on mine pillars and supports and their strength. 4/ 5/ During this period, investigations were conducted in both the laboratory and the field in the comparatively shallow load and zinc mines of Missouri and Oklahoma. As a result a seismic method of determining the pressure on mine pillars was developed.Before this research program was initiated, Chas. F. Jackson, chief of the Mining Division, suggested that rock under pressure might give rise to noises inaudible to the unaided ear - that is, subaudible noises. As a result of this suggestion, listening tests were made concurrently with the routine pressure measurements to see if any rock noises were present; with one exception, it was found there were no rock noises in any of these shallow mines. At the same time, pressure measurements disclosed that, with one exception, pillars were not under pressure amounting to more than 10 percent of the crushing strength of the rock. The one exception was a pillar in the Big John mine of the Eagle Picher Mining & Smelting Co. in the Tri-State district, which showed some physical evidence of failure, such as small cracks and spalling; it was reported that the pillar had been heard to crack or snap at intervals. Listening tests in this pillar disclosed that subaudible noises of comparatively small intensity were present and occurred at 1- to 2-minute intervals, on the average. Unfortunately, owing to the shortness of this pillar it was impossible to make any pressure measurements."

Jul 1, 1942

By Raquel Costa, Aldino Campos, Frederico Carvalho Dias, Pedro Madureira, Patrícia Conceição, Ana Filipa Marques, Andreia Afonso, Maria Ana Martins, António Calado, Luísa Pinto Ribeiro

Since its formation in 2004, the Task Group for the Extension of the Continental Shelf (EMEPC) has been collecting hydrographic, geological and geophysical data to support the extension of the continental shelf beyond 200 NM. In 2008, the EMEPC acquired a 6,000 m rated ROV named "Luso" and has been cooperating with several national and international institutions to increase and improve its operational capabilities to conduct research on deep-sea minerals. The Portuguese continental shelf corresponds to a broad area of the seafloor encompassing different physiographic domains: the mid-Atlantic ridge system, abyssal plains and numerous seamounts. From 2008 to the present, the mid- Atlantic ridge and seamounts have been the most visited sites with the ROV "Luso". Several hydrothermal vent sites are known to occur along the mid-Atlantic ridge to the south of the Azores archipelago and mostly within the Portuguese EEZ. Vent fields were also discovered in the extended continental shelf, namely the Rainbow and the Moytirra sites located to south and to the north of the Azores archipelago, respectively. The most studied seamounts correspond to those forming the Great Meteor chain and the Madeira- Tore rise. All these visited sites are related either with the occurrence of polymetallic sulphides or cobalt rich Fe-Mn crusts and the opportunities to further pursue their exploration will be discussed.

Sep 1, 2014

By Tony Moore, Peter Riccio

"MMG (Minerals and Metals Group) operates the LXML Sepon’s mineral processing facility located 40 kilometers north of the town of Sepon, in the Savannakhet Province, Lao PDR. The Sepon copper plant produces 70,000 tons/year of LME grade A copper cathode using leachautoclave- SX/EW-flotation technology (Baxter et al., 2003). Pyrite recovery in the flotation circuit is critical to the operation, as it is used to generate acid and soluble ferric ion for the leach circuit. Low pyrite recovery has been an on-going challenge in the flotation circuit. Final tailings characterization work done by Ian Wark Research Institute (Bassell et al., 2006) showed that the pyrite losses to the tailings are made up of a combination of coarse liberated particles and finer particles that have been coated by clay fines.In December of 2005, a joint Cytec-MMG technical program was initiated to address the pyrite recovery issue. A series of diagnostic tests were performed in the Cytec Stamford Research Facility using synthetic plant water showing that the collector was precipitating as a metal salt and was unavailable for mineral attachment. The tests also identified several collector chemistries that would likely be robust in the low pH (< 1), high dissolved metal ion environment and will not complex with metal ions in solution. With the support of the Sepon on-site engineers, an extensive, successful laboratory program was completed, which was subsequently followed by on-plant testing that showed a step wise improvement in pyrite recovery.INTRODUCTIONLow pyrite recovery has been an ongoing problem in the flotation circuit at Sepon. Sulfur recovery (indirect measure of pyrite) was improved from 40% to 65%-75% in mid-2005 when on site laboratory work confirmed that AERO® 8045 Promoter was a more effective collector then AERO® 407 Promoter. However, sulfur recoveries above 65% could never be achieved. Sepon requested the Ian Wark Research Institute to complete a surface analysis study using Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, and Time-of-Flight Secondary Ion Mass Spectroscopy to determine if clay coated pyrite played a role. It was concluded that the pyrite losses to the tailings are made up of a combination of coarse (+ 100µm) liberated particles and finer (-74µm) particles that have been coated by clay fines. The majority of the losses appear to be due to the former. In December of 2005, a series of diagnostic tests were performed in Stamford using synthetic plant water in order to identify what chemistries would likely be robust in the slimy low pH and high dissolved metal ion solution environment. Results showed that several chemistries would not complex with ferric, ferrous or copper in solution and therefore should perform well in the Sepon flotation. The incumbent collector, AERO® 8045 Promoter was complexing with metal ions in solution. This resulted in the collector not being available for adsorption onto pyrite."

Jan 1, 2011

By Jay A. Carpenter

THIS preliminary report from the Committee to Study Relations Between Students and the Institute is submitted to our member- ship for consideration and discussion before the general subject comes up for action at the Annual Meeting in February. At present, the A. I. M. E. has a dual relationship with mining students, each relationship in no may connected with the other. To the individual student the Institute offers for $2 a year a Student Associateship in the Institute which carries with it a subscription to MINING AND METAL- &apos;LURGY, a watch fob, and the privilege of becoming a Junior Member after graduation without payment of the -first year&apos;s dues, if one&apos;s application is accepted. To the student&apos;s college society it offers the privilege, upon application, of becoming &apos;an Affiliated &apos;Society, which brings with it no specific supervision or aid, and in turn requires no specific conditions as to membership, fees, or rules. This Affiliated Society is distinctly a school organization which Student Associateship in the Institute can he given special status or ignored, is the local .society sees fit.

Jan 1, 1934

By John Convey

This paper, a follow-up to an earlier study, gives the history of Canadian developments in mineral processing from 1921 to the fall of 1964. It deals extensively with comminution and flotation, and then goes on to cover the fields of gravity concentration, magnetic concentration, cyanidation, the processing of uranium ores, and instrumentation. Several outstanding examples of installations are given. The paper concludes with a discussion of present-day trends in mineral processing. Introduction T HE history of the developments in mineral processing in Canada from its earliest times to 1920 has already been published by one of the authors (1). The present paper is thus a logical follow-up to bring this history to date. From 1834 to 1920, mineral processing in Canada, as elsewhere in the world, was in its formative stage. This, however, prepared the ground for developments that have resulted in a mining empire from the Atlantic to the Pacific, a mining empire which could be said to be almost on par with that in the United States.

Jan 1, 1965

By Colin Lawrence, Michael S. Schultz

Due to the planned deepening of the NY Harbor, NYCEDC/NYCDEP is planning to replace two existing water lines between Brooklyn and Staten Island with one deeper water pipe. The crossing, just north of the Verrazanno Bridge is 1.75 miles long. The new pipeline will be tunneled using gasketed concreted segmented liners. Apressurized face machine will be used through the soft ground. This will be the first subaqueous application using this technology in New York City. This paper discusses the planning, design and risk issues associated with the crossing and the challenging soil conditions that resulted in the decision to use a pressurized face machine.

Jan 1, 2007

By D. Harrington

United States newspapers of 25 or 30 Years ago ran headlines every few weeks telling of some mine disaster. Each disaster was a first-page attraction for a day or so then was forgotten until the next sensational event, frequently another mine disaster, a few weeks later. Interspersed with the large mine disasters were the so-called ?snipping? mine accidents that caused the death of one or two mine workers. The summation of mine fatalities of all types usually exceeded 3,000 a year, and nonfatal accidents to workers in mines of the country approximated 250,000 annually. From 1906 to 1910, inclusive, there were 84 major explosion disasters (about 17 per year) in. United States coal mines. The resulting fatalities totaled 2,388 for the 5-Year period. These frightful catastrophes helped the number of fatalities in coal mines of the country to reach the enormous total of 13,288 for the 5 years, or an average of 2,658 per year.

Jan 1, 1940

By V Ser, R Crosbie

To date, Anglo American Research Laboratories (AARL) has carried out several projects, based on the techniques developed in AMIRA International LimitedÆs (the mineral industries research association) AMIRA P9 project, to develop models for several Anglo Base Metals flotation plants. Further detailed analysis of the data which was generated has realised additional benefits: the various hydrodynamic measurements were useful in comparing cell operating parameters to literature sources, while the laboratory batch tests give an indication of plant recovery potential. A detailed cell by cell mass balance, which is a critical feature of the modelling process, is in its own right a valuable diagnostic tool. Several examples of how this can be used to highlight potential improvement areas in the plants are presented. The added understanding gained from sampling each cell is clear and this is shown to more than compensate for any necessary modifications needed to allow sampling to take place. The model fitting process generates an ore floatability distribution, which is used in the JK SimFloat simulation package to assess the effect of possible changes to each of the circuits. An example of an actual circuit change as a result of this approach is presented. The current limitations of and the potential improvements to the modelling process are also briefly discussed. Future models will be extended to include enhanced size and mineralogical information where the basic models suggest this has potential to improve understanding.

Jan 1, 2005

By S Döpp

Commencing with early experiences in iron ore beneficiation made at Beeshoek Mine, the paper follows through the process of extensive mineralogical and metallurgical investigations carried out during feasibility study. The paper will discuss the design process and logic followed over the last years, the challenges and decisions the design team faced in order to draw the conclusions that ultimately resulted in today’s value add approach at Assmang’s Khumani Operations.As integral part of the benefi ciation concept, a focus is set on the jigs, explaining the plant concepts, planned expansions and their contribution to the overall value add approach at the mine.The case study is intended to describe the outcomes of the design versus the actual achieved and the further value add projects to be implemented. As for future prospect, the incorporation of Wet High Intensity Magnetic Separation (WHIMS) demonstrates Assmang Khumani’s pursuit to maximise productivity and overall recovery.DMS was evaluated as an alternative to jigging within a comparative test work study, but in conclusion the option had to be excluded due to its inability to achieve the high density cut point required to achieve the sales specifi cations. In contrast, the investigation on producing an additional middlings fraction on the lumpy ore jigs prove to be an adequate option for further improvements of overall mass yield. With further liberation, a saleable product will be achieved by secondary beneficiation on Fines Jigs and WHIMS.Concluding, jigs are considered the most viable and cost effective benefi ciation process for off-grade ore +0.8 - 32 mm at Beeshoek as well as at Khumani, while WHIMS is the process under consideration for super fines recovery.

Jul 11, 2011

By A. G. Loomis

Although secondary-recovery methods have not been applied widely in California, it is apparent that increasing attention and effort must be given to this phase of recovery if the State is to maintain its high rank as a petroleum producer. Steadily increasing demands for petroleum products and decreasing rates of discovery of new oil fields, with rapid depletion of existing reserves, emphasize the prospect of an adverse situation of supply and demand in the not-far-distant future. If the trend of discoveries becomes more favorable or if more complete economic recovery of the oil in place can be obtained by secondary recovery, this situation can be averted. Not only are these reserves of economic importance to the petroleum industry for meeting increasing market demands; but economic reclamation of such reserves is an important conservation measure, which will prolong the productive life of many fields. Accordingly, progressive operators in California are alert to the possibilities of secondary recovery and have done much to implement such operations wherever feasible. Most current operations are of the pressure-maintenance type, in which the reservoir pressure is maintained or partly maintained by injecting natural gas to in-crease oil recovery. The possibilities of recovering additional oil from stripper fields by gas drive and water flooding (including water disposal) also are being tested in experimental field projects. Table 1 summarizes current gas-and water-injection projects in California.

Jan 1, 1952

By W. W. de Graaf, M. J. Ntsekhe

Klipspruit Colliery is experiencing coal losses, which leads to a negative impact on coal production and subsequently loss in revenue. This study aimed to identify the possible causes of coal losses in the No. 4 upper and lower seams. The objectives were to identify potential sources of coal losses through a literature survey, to identify areas where the coal losses occurred, to determine factors affecting coal losses, and to identify the most cost-effective methods to reduce coal losses. Highwall losses, top-of-coal losses, and coal edge losses were identified as the major areas of coal loss at Klipspruit. These losses were mostly attributed to the drilling and blasting practises of the pre-split, interburden waste, and the coal seams. Recommendations include re-visiting the current pre-split design and the tolerances adopted for the interburden and coal seam drilling and blasting design. It is furthermore recommended that Klipspruit implement a continuous improvement plan for the drilling and blasting and refresher training for the blasting crew and operators.

Jun 10, 2024

By Gregory M. Dexter

Recent litigation in Pennsylvania between three coal-mining companies and a private water company resulted in the payment by the coal companies of the equivalent of about $500,000 to buy a new water supply to replace that which had been damaged by acid drainage from strip mining. An investigation of the relevant facts indicates that the water could have been treated by spending about $40,000 on equipment and $15,000 yearly for chemicals, labor, and power until the contamination could be reduced about 80 pct. The water company&apos;s supply, furthermore, had deteriorated largely by reason of dry weather before stripping was begun by the coal companies. Payment to the water company should not have exceeded $300,000 and could have been as low as $100,000. Strip mining of coal is common in Pennsylvania. The most important objection to it in Pennsylvania is generally acid pollution of runoff water. An outline of the methods, therefore, that could be used to reduce such pollution, to compare acid-contaminated waters, and to treat such waters to make them satisfactory for public and industrial use is worth-while. The watershed of the West P~M Water Co. covers about 4.5 square miles, 20 miles west of Pittsburgh, and has two 90,000,000 gal reservoirs sup- plying about 1,300,000 gal daily for public and industrial use of which 450,000 gal daily are for two railroads. The pollution arises from weathered derivatives of typical "Coal Measures"

Jan 1, 1949

By Mao Bai

In predicting the integrity of under-mined structures, surface horizontal displacements and curvatures are frequently of greater importance than the more homogeneous vertical displacements. Accurate evaluation of mining induced subsidence and horizontal displacement further requires that the predictive model adequately represents the subsurface geology, mining geometry and extraction sequencing. The following documents an extension of the Subsidence Prediction and System Identification method (SPASID) to the evaluation of horizontal strains. Comparisons are made between predictions from SPASID and two other empirical methods against measured data from a case study. The system identification method is illustrated to predict horizontal displacements and strains most consistently with the in situ data.

Jan 1, 1989

This manual provides basic practical instruction on the inspection of driven piles. It covers the essential components of pile driving, such as the pile driving hammer, hammer accessories, the pile and soil, and frequently encountered test methods in an uncomplicated, yet knowledgeable, and practical manner. Insight is given into the methods of installing the foundation, dealing with the cranes which do the lifting, the hammers which do the driving, the leads that guide the hammer and pile, the compressors which provide the external power when required, and finally prevalent analysis tools and testing instrumentation and procedures which enable you, the Inspector, to do your job. This DFI Inspector&apos;s Manual for Pile Foundations will help the Pile Inspector who has limited knowledge of pile foundations. Perhaps this Inspector has been pressed into service at a moments notice; a few helpful hints and suggestions to him are desperately needed and he can look here for the basics. It is also useful for the experienced Pile Inspector as a reference guide. However, this manual is not a detailed check list of every possible scenario and detail which could ever be encountered. There are other sources available which give more detailed descriptions (and should be consulted by the Inspector when appropriate; a list of this additional reference material is provided and suggestions made in appropriate chapters of this text). The current manual is more a brief "textbook overview" with some of the more important aspects given at least some emphasis so that the Inspector has some direction and hopefully helps to produce a safe, yet economical, foundation.

Jan 1, 1997

By G. R. Fitterer

In the manufacture of steel by any process the refining period involves the partial elimination of the metalloids carbon, manganese, phosphorus, and silicon, by virtue of their reactions with ferrous oxide. At the end of this refining stage the metal consists chiefly of iron in which small amounts of these materials are dissolved. Unless some deoxidizer is added to the steel at this time, the reaction between carbon and ferrous oxide will continue with such force that it is impossible to form sound steal in the ingot molds. Instead, the product will exhibit a marked porosity due to the formation and trapping of carbon monoxide-the product of the reaction mentioned. However, if deoxidizers are added, steel may be obtained which is dense and free from gas bubbles. At the same time the deoxidation products will remain in the steal as impurities. For example, silicon additions form Si02 or combinations of Si02 and FeO. Additions of manganese form deoxidation products consisting of various proportions of MnO and FeO. It is also quite obvious that simultaneous additions of manganese and silicon will form oxide combinations either in the binary system MnO-SiO2 or in the ternary system FeO-MnO-SiO2. Work at the Pittsburgh Experiment Station of the United States Bureau of Mines, in cooperation with the Carnegie Institute of Technology and the Metallurgical Advisory Board, involved the study of such deoxidizing reactions and their products. In this connection considerable information is necessary concerning FeO, MeO, Si02, and Al 203, and their various combinations. Some of the most needed data are the melting points of all of these materials. At the outset of this work ordinary methods of melting point determinations were found to be inadequate for various reasons, and the procedure finally selected involved the use of the micropyrometer with occasional corroboration by quenching methods, The reasons for this selection, together with a description of the apparatus, are given in the following pages.

Jan 1, 1932

By Luis E. Vallejo

The strength measured by the uniaxial compression test is a parameter that is widely used for the engineering classification of rocks. Sedimentary rocks such as shales, however, are difficult to evaluate by uniaxial compression tatting because the rocks slake during the preparation of the standard samples required for the tests. Indirect methods such as the point load test have been proposed to determine the unconfined compressive strength of shales and other soft rocks. It is current practice to use 24 as the conversion factor between the point load strength, Is, and the unconfined compressive strength, sf (sf = 24 Is). The present study investigated index-to-strength conversion factors for shales and sandstones obtained from surface coal mining sites in the Appalachian region. Regression analyses indicate that a conversion factor of 12.5 best correlated the strengths obtained from the point load and unconfined compression tarts in the case of shales. For the sandstones, a value of 17.4 best correlated the strengths.

Jan 1, 1989

By Paul Hatmaker

Lime was a highly useful commodity thousands of years before the simple chemistry of its manufacturing process was known. The employment of lime for agriculture, building, and even certain essentially chemical purposes is so old that its origin is among the unrecorded details of man&apos;s first ventures into the manufacture and use of prepared substances. Lime is a most versatile material and consequently has come to be widely utilized in modern civilization. Immediately before the depression of the early 1930&apos;s the annual production of lime in the United States was more than 4 million tons, valued at 33 to 42 mil-million dollars. This output was sold to many industries, so many that mere enumeration becomes tedious.

Jan 1, 1934

By D Tuazon, M Powell, M Ziemski, G D. Corder

Although mining companies have made broad corporate-level commitments to adopt sustainability, there continue to be problems when attempts are made to adopt higher-level sustainability aspirations and translate them into appropriate targets and methods at the more-specific operational level. The integration of sustainability principles into minerals processing operational decision-making processes has unique challenges that are not addressed adequately by current tools and methodologies, yet impacts from operational decisions can have longer-term effects realised at closure and rehabilitation.This paper describes a proposed methodology to achieve the integration of sustainability at the operational level through a systematic and rigorous process of identifying and qualifying sustainability issues and opportunities in an operation. The methodology, starting from a sustainability point of view rather than an operational one, guides the identification of process issues and opportunities by examining the operation, unit-by-unit, similar to a Hazard and Operability (HAZOP) process. Each issue or opportunity is qualified according to its measurability, scopes of impact and consequences so that it may be understood fully and the correct engineering problems are formed. Through improved decision-making to account for broader sustainability factors, operations can better address environmental and social expectations and pressures (both corporate and community, as well as immediate and in the longer-term), whilst still delivering on operational and business goals.The methodology has been tested with two case studies at minerals processing operations. At one site, the methodology identified a dust issue which had considerable business risks (loss of valuable product) compared to conventional engineering analysis processes. The other site also benefited from using the methodology as an opportunity to improve the operation of the milling and flotation circuits was identified. The opportunity not only showed a potential to improve operational efficiency, but also potential improvements in water and energy efficiency and a resulting increased resilience against water and energy supply risks. It was important to utilise the holistic approach of the methodology in the identification of opportunities at this site; the goals of the operation showed a strong coupling between water and energy issues which would be difficult to overcome using the operationÆs current organisational model, which deals with such issues separately of each other.CITATION:Tuazon, D, Corder, G D, Powell, M and Ziemski, M, 2012. A practical and rigorous approach for integrating sustainability principles into decision-making processes at minerals processing operations, in Proceedings Life-of-Mine 2012 , pp 233-242 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By Blanchard R

The discussion submitted by Drs. Stillwell and Edwards is at once helpful and gratifying to the authors. Their contribution deals with two phases of the problem-(I) an additional suggestion for the relative solubility of galena and marmatite, and (2) submission of an alternative explanation for the greater leaching of the Northern ore-body. With the first we agree in principle, and herewith present recent data which will help to substantiate the idea, though the mechanism is not believed to be as simple as indicated by Stillwell and Edwards. Concerning the second suggestion, the original explanation put forward. in the paper is held to fit the facts more closely.In view of the influence, as shown by Garrells&apos; paper,in which the presence of Cl&apos; ion may have upon the relative solubilities of lead and zinc, it is perhaps worth noting that Broken Hill mine water carries a higher content of Cl&apos; than has been reported from many of the other lead-zinc districts.Since our paper was published, an analysis of water issuing from the newly-opened Northern ore-body on the 2,600-ft. level has been made (12/1/43). It is compared with that quoted in the original paper as follows:

Jan 1, 1943