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By HOWARND N. EAVENSON

THE year 1930 resembled the preceding one in the coal industry in continuing the era of falling prices and 'of the abandonment of unprofitable mines. Practically all coal prices fell, and in the steam sizes during the last half of the year this was particularly true, due to the small industrial demand. No new mines of any size were opened in the bituminous coal industry, but there was a steady increase in the number of cleaning plants of all kinds built in all fields. It is estimated that at least nine million tons per year were added to the previous total of washed coal. The largest washing plant started during the year was that of the Buckeye Coal Co., at Nemacolin, Pa., with a capacity of 650 tons per hour. Fig. 1 shows - the mixing-bin, conveyor galleries, washing-plant and skip hoist, and Fig. 2 the 120-ft. Dorr thickener for collecting the 48-mesh material from the wash water. Dryers are used for drying the steam coal product. The following statement by J. R. Campbell shows the effect of cleaning on Pittsburgh coal in Greene County: "With the advent of the 650-t.p.h. efficient washing plant in Greene County at the Nemacolin mine of the Buckeye Coal Co., it has undoubtedly been demonstrated that the potential coking-metallurgical coals of the county can be brought within the pale of the highest grade high-volatile coals for steel manufacture. A few months' operation indicates that 9% per cent ash in the raw coal can be easily reduced to under 7 per cent ash in the washed coal and the sulfur from 1.60 per cent in the run of mine to 1.20 per cent sulfur in the washed coal.

Jan 1, 1931

By Robert Linton

M ETHODS by which Americanization is developed among the foreign workers at the mines in the United States, with particular reference to mines of the Pennsylvania coal region, were discussed in a most constructive way at the Wilkes-Barre Meeting of the Institute. Arthur Notman, of the Phelps Dodge Corpn., as chairman, guided the discussion. Americanization was defined by E. E. Bach, !chairman of the Institute's Sub-committee on Americanization, who said: "Americanization applies either to the native-born or foreign-born and is that process of assimilation which guarantees the full functioning of American citizenship. Naturalization papers merely entitle one to the privileges of citizenship."

Jan 1, 1921

By D. S. Sanders

IN the four mills of the Cerro de Pasco Copper Corp. in Peru, some 3000 tons of complex sulphide ores are treated daily, with four kinds of concentrates produced: copper, lead, zinc, and pyrite, each containing values in silver, gold, bismuth, and some other metals. Copper occurs in the various ores as chalcopyrite, enargite, tetrahedrite, tenantite, bournonite, and chalcocite; lead as galena; and zinc as sphalerite and marmatite. Small amounts of silver and tungsten minerals are also present. The gangue consist mainly of shale, quartzite, calcite, rhodochrosite, pyrite, and pyrrhotite. In general the values are freed with a relatively coarse grind, about 70 prr cent minus 200 mesh being the finest to which the pulps are ground. In Morococha and Casapalca however. sphalerite particles much finer than this contain inclusions of chalcopyrit r. At Cerro de Pasco the silver and gold are present in all sizes of the ground pyrite.

Jan 1, 1945

By Paul M. Tyler

THE winning of metals from Nature has been advanced to a degree of efficiency that commands admiration even in this Machine Age. Economy of human effort underground, in surface plants, and in treatment works, and better means of performing all manner of operations have cut costs and im¬proved products to an extent that seems far beyond the wildest imagin¬ings of those that labored in the days of hand mining and muscular metallurgy. Principles and methods borrowed from other professions and sciences - mechanical engineering, chemistry, and physics-all have con¬tributed to the rapid development of ore production and treatment, but no small part of the achievements must be credited to the free exchange of ideas within the industry itself and mass attack upon problems of mutual concern. The esprit de corps or class consciousness that has contributed so effectively to the progress of the metal industries has been less apparent among nonmetallic mineral producers. As a class they have been handicapped by inadequate contact with the metal-mining fraternity as well as among themselves.

Jan 1, 1935

By Partha Sircar

"For Berth 22 modifications at the Port of Oakland, nearly 600 octagonal 24-inch ‘diameter’ precast-prestressed concrete piles were driven, some piles over 160 feet long. Prior to production pile driving, an indicator/test pile program was performed, which included extensive use of dynamic load testing with (Pile Driving Analyzer (PDA) & CAPWAP analyses. The indicator test-pile program resulted in requiring significantly longer piles than the original design based on subsurface borings. The cause of this discrepancy is investigated in light of the available geotechnical information, soil mechanics principles and standard techniques for pile capacity computations. Several interesting phenomena emerged. These include relatively low resistances offered by crushed rockfill than would conventionally be assumed, non-homogeneity of an apparently uniform formation and the effects of jetting on pile side friction. Also revealing was the significant increase in capacity between 1 and 3 weeks of driving for long piles in clay. Recommendations were developed for pile capacity for future use as “lessons learned”.IntroductionThe foundation for the replaced Berth 22 structure at the Port of Oakland in California involved driving approximately 570, 24-inch octagonal precast prestressed concrete piles. A plan and a section for the pile locations are presented in Figure 1.The ultimate loads on the piles used in the design are presented in Table 1 – the loads are quite heavy.The foundation design was followed by an extensive Indicator Pile Program. The contractors (Manson Construction Co. of Richmond, California) opted to use a Delmag D62-02 diesel hammer (Rated Maximum Energy – 165 kip-feet). Per the project specifications, the same hammer was used for both indicator and production pile driving. The production piles of appropriate lengths were ordered based on thr results of the Indicator Pile Program. A number of interesting results were found from the Indicator Program, which is discussed in this paper."

Jan 1, 2015

By AIME AIME

OVER-ALL operations of the oil industry, as measured by production of crude oil and consumption of products, are almost exactly of the same magnitude as a year ago. Does this mean that the great oil industry has been undisturbed by the war? Has this industry, so vital to the prosecution of the war and to the maintenance of our way of life, been unaffected in its operations? No indeed - changes within the industry are great. It has been called upon to revamp its trans¬portation methods so as to move about one fourth of the total amount of crude and refined products by railroad tank car instead of by ocean-going tankers. Its fundamental internal economy, based on maximum gasoline yield from a barrel of crude, has been relegated to memories of the past. Rationing of oil products, which has been forced upon us in face of an abundant supply, is not only disagreeable medicine but is in itself completely disruptive to the marketing end of the-business.-

Jan 1, 1942

By Georgc E. Collins

SEVERAL years ago, I estimated the total stock of gold in the world to be about a thousand million ounces, of which rather over one-third was available for monetary uses. Robert H. Ridgway has estimated the world's production from 1493 to 1927 as slightly over this amount. Of this total, 1.5 per cent was produced between 1493 and 1850 (before the Californian and Australian goldfields began to flood the world with gold), 331/2 per cent from 1851 to 1900, and 511/2 per cent from 1900 to 1927. Allowing for loss by attrition and permanent consumption in the arts, and for loss of buried treas¬ure, my first-mentioned estimate is perhaps not far from the truth; but my estimate of the monetary stock was certainly too low. Of the total production stated by Rid-way. 28 per cent came from North America. 26.9 per cent from Africa, 1.6.8 per cent from Australasia, 12.4 per cent from South America, and 11.2 per cent from Asia. Excepting that from the African conglomerate beds, the ultimate origin of which is still the subject of controversy, by far the greater part of the total production was derived from alluvials. Weighing all contingencies, it is improbable that any such production as has been made during the last forty years will be repeated in any similar period, if the present price level is maintained. The gold standard today seems firmly established except for temporary digressions. Nevertheless, no well-informed mining engineer will venture to assert the probability that the material for its maintenance throughout future generations can be furnished.

Jan 1, 1932

By AIME AIME

PRACTICALLY all the Section delegates as well as a sprinkling of Institute officers and mere members were on hand for the annual business meeting of the Institute on Monday afternoon of the Annual Meeting. President McAuliffe presided, with C. H. Mathewson as associate chairman. Americo Albala was first called on to discuss the work of the Pan American Institute of Mining Engineering and Geology. C. Will Wright said that the need for such an organization was evident, and a resolution was passed asking the incoming President to appoint a committee to investigate cooperation with that body, of which Mr. Albala is executive secretary.

Jan 1, 1943

By John Mould, Gordon Chen, Michael Oakland, William McElwee

"This paper will discuss the design analysis of sheet pile cofferdams for static and dynamic blast loads. Following construction of the new Willis Avenue Bridge across the East River between Brooklyn and Manhattan, in-river piers No. 9 and No. 10 from the former bridge were demolished, partially by explosive charges. The blast at Pier 10 was conducted first and though the demolition charge was relatively small, it gave confidence that the sheeting could be designed to resist the blast load. This paper primarily summarizes our analysis and performance of a sheet pile cofferdam at Pier 9 used to withstand the larger blast loads, contain the blast debris, and allow excavation of the pier below the existing river bed mudline. The program NLFlex was used to predict stresses and deformations of the cofferdams under dynamic blast loads, using simplified equations to estimate the underwater blast pressures. Specifically, the analysis focused on the stresses in the struts, waler beam, sheet pile interlocks and connection of the sheeting to the waler beam. Design included allowing plastic deformations and limited rupture of the sheet pile interlocks under the blast loading. Comparisons are made between stresses assessed by the dynamic finite element modeling and empirical relationships used within the industry. The performance of the system after the actual blast is discussed as well as details of the performance of welded vs. bolted connections within the system. IntroductionThe Willis Avenue Bridge is one of the major access ways from the Bronx into Manhattan. The location is shown on Figure 1. The original bridge constructed in 1901 was a swing bridge over the East River. The bridge was in disrepair and outdated with regards to its ability to handle the flow of traffic resulting in numerousaccidents.In 2007, Kiewit Constructors Inc./Weeks Marine, Inc., A Joint Venture was selected to construct a replacement bridge. The $612 million project included construction of a new bridge just to the south of the original bridge. The most notable aspect of the construction was floating and lifting the new 350 ft. long swing span in place as a single piece. However, another significant challenge was using blasting to demolish two of the abandoned piers which were within the East River. The blast would be near existing structures in both Manhattan and Brooklyn and would be within 30 ft. of the new bridge."

Jan 1, 2017

By Courtenay de Kalb

THE Exposed Treasure gold-mine has, for the past four years, been one of the largest producing mines of Southern California, its annual output having constituted 1 per cent of the total gold and silver production of the entire State. At the present moment the property is idle, owing to the large quantity of water encountered oil the lower levels, which will require the installation of a powerful pumping-plant before operations can be recommenced. Moreover, a prompt change in the character of the ore has occurred at water-level, which makes imperative an extensive campaign of development in the region of the unoxidized ores before a plant adapted to their treatment can be definitely decided upon. The character of the changes encountered in these deeper ores makes the geology of this deposit a matter of importance, not only for the immediate district, but for the desert region of Southern California in general, where many mines exist having in the oxidized belt conditions that, in many respects, resemble those in the Exposed Treasure mine. The deposit is situated in an apparently isolated butte about 2.5 miles south from the town of Mojave, on the Mojave desert; The butte, though apparently isolated, is in fact geologically part of an extinct volcano, known as Soledad butte, which rises out of the plain 1,5 miles SW. of the mine, to an altitude of 4,650 ft. above sea-level. Other buttes also rise from the desert plain toward the south and east, and again to the westward, all being closely related geologically to Soledad butte,-the whole constituting a single system as to origin and time. Since the end of the period of active volcanism in this region, there has been extensive denudation, the ancient plateau having been dissected during an epoch of apparently exces-

Jan 1, 1907

By H. LIVINGSTONE LMAN

A GOOD DEAL of information concerning flotation has come out during the patent litigation of recent years, and the legal situation has cleared considerably, to the satisfaction of Minerals Separation, Limited. Hence, Mr. H. Livingstone Sulman, one of the originators of the successful process of that company, felt at liberty to explain, on Thursday, Nov. 20, his experience and his views in a "Contribution to the Study of Flotation," before the Institution of Mining and Metallurgy. He did not give technical details. He dealt with the physical problems, so simple, as he remarked, that he had wanted 96 pages to express his views. He presented much data, partly new and based on observations of his own, bearing upon the very complex flotation phenomena in an instructive wav and made frequent references to the valuable researches especially of Prof. Edwin Edser and Mr. Emil Hatschek.

Jan 1, 1920

By William B. Millar

IN ONTARIO development of the gold mines is being rapidly pushed, while the intensity of the search for new mines has probably not been equaled at any time in the past. Even to outline the results of recent prospecting activity in Ontario would be a big undertaking, but it would be timely and, I hope, interesting to Institute members to review some generalities regarding the work of the prospector and then to discuss in some detail the growth of Ontario's most promising prospect area, the Swayze district, where serious mining operations are already under way. Probably no one writing about prospectors and pros¬pecting can resist hoping that his article will not reach the eyes of a certain portion of the uninformed general public and cause a further influx of "prospective prospectors" into any given area. It is somewhat mystifying how so many people reach the conclusion that prospecting is in

Jan 1, 1933

By A. Ribeiro

The effective utilization of resources and process optimization play a crucial role in the sustaining and growth of overall businesses. This principle holds true in the mining sector, where particular attention is required during the comminution steps. This necessity arises from the fact that mining operations often consume substantial amounts of energy in mineral processing. Therefore, it becomes imperative to thoroughly study the integration of comminution steps. In many instances, an approach to be studied is the operation commencing with the drill and blast phase and culminating in the grinding product process. Nevertheless, establishing an optimal integration between drill and blast operations and the grinding phase is a complex undertaking due to the direct influence of rock characteristics on this process. And in many cases, the complexity and variability of such physical characteristics makes mining operations to ignore such influence. Consequently, Enaex Mining Technical Solutions (EMTS), in collaboration with Lundin Mining's Chapada Mine engineering team, and with the assistance of Hatch Consulting and Technology, has undertaken a comprehensive study aimed at enhancing mill throughput at the Chapada operation. The basis of this study lies in characterizing the rock masses present in the Chapada Mine to gain a deep understanding of the material that needs to be comminuted. Subsequently, the mineral processing team determined the most suitable size distribution for the Run-of-Mine (ROM) material. With this information, the drilling and blasting team built a site-specific blast fragmentation model, able to simulate various blast design scenarios. This approach enabled to optimize the utilization of available drilling and blasting resources while striving to achieve the optimum ROM characteristics. Since 2021, the Mine to Mill methodology has been progressively implemented at the Chapada Mine. As a result, the blasting engineering team now utilizes the blast plans generated by the fragmentation model simulations as a foundation for designing blast plans that align with the operational and financial capacities of the mine. Overall, it was predicted that this implementation could lead to an average increase in mill throughput of 13-22 % depending on blend feed, once all recommendations are implemented. Even with partial implementation, plant results demonstrate a 5 % increase compared to the period before the Mineto-Mill project, without any coarsening of the associated grinding product size.

Jan 1, 2024

By M. Arlandi-Rodríguez, and A. García-Berrocal, A. Alonso-Jiménez, C. Lopez-Jimeno

Spain is a major producer of dimension stone, which is one of the most important industrial sectors in the northwest of Spain. This justifies the maintenance of these industries, although the technical and environmental requirements for their continuity are increasingly demanding. The main target of this paper is to present a new methodology in order to obtain k-ratio stress values on the basis of flat jack measurements and finite element numerical back- analysis with Rocscience© RS2 software. Continuous iterations were performed to try to find a relationship between the k₀ and the measured stress in the tunnel roof and sidewalls. It focuses on technical aspects of the method for designing mine chambers in the slate industry that were previously mined by open pit methods. The size of the chambers impacts the operating cost, and the dimensioning of a correct support ensures better efficiency and safety. Correct knowledge of the k₀ therefore is critical for the design of the support. The proposed new method entails a simplification of the classical procedure for estimating the k-ratio.

Sep 1, 2022

By Massimilinao Svetina

In 2010 Danieli & C. S.p.A. put into operation a new Pickling Tandem Mill in Cremona (Italy) at Acciaieria Arvedi, the last Pickling line coupled Tandem Cold Mill (PLTCM) in Europe. The plant was tailor-made to suit the specific requirements of this customer; a very broad range of sizes and grades (IF to AHSS as well as DP and TRIP1000) including ultra-thin hot band can be processed, achieving a total capacity of 1.6 Mt/y. The Danieli & C. S.p.A. Turboflo® process was selected because of its proven efficiency and ability to handle ultra-thin gauges at speeds exceeding 400 mpm in the pickling tanks. All the equipment, i.e. pickling section and rolling mills was provided with the last generation of Danieli market-oriented technologies. Danieli & C. S.p.A. - with the support of Arvedi and feedback from the field - is continuously improving its technical design solutions and optimizing plant operations.

Aug 16, 2017

By Bo Liang, Hongmin Zhu, Kai Huang, Shafiq Alam

A new approach of recovering platinum and palladium from electronic wastes by hydrochloric acid leaching followed by selective adsorption on low-cost and environmentally benign biomass sorbent prepared from easily available agriculture waste is suggested. The obtained adsorbents were prepared by a combination of chemical modification and hydrothermal carbonization process with (NH4)2C2O4. It was found that the maximum adsorption capacity of hydrothermal carbonized garlic peel for Pt( ) and Pd( ) was 1.64 and 0.42 mol/kg respectively. The Langmuir adsorption isotherm was applied to describe the adsorption process. Kinetics of the Pt( ) and Pd( ) ions adsorption was found to follow pseudo-second-order rate equation. The adsorbents were examined by scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR). Based on the characterization results, a possible mechanism of Pt( ) and Pd( ) ions adsorption with the hydrothermal carbonized garlic peel was proposed. This study provides a promising adsorbent with efficient adsorption property for platinum and palladium recovery from the leach solution of electronic wastes.

Jan 1, 2016

By M. Le Roux, Q. P. Campbell, M. Fofana

The determination of densimetric information to predict coal washabilities is an important step in characterising the feed material, as well as the performance of operating plants. However, traditional methods like float-and-sink analysis are hazardous and time-consuming. This is especially true for finer particle size ranges, where very long settling times are required in a medium. De Beers Technologies recently developed a density analyser, known as the RhoVol, for use on diamondiferous kimberlite. Operating over size ranges from 25 mm down to 3 mm, it can determine the mass, volume, density, size and shape of all the particles in a given population and is thus able to provide information about the densimetric distribution on a single particle basis. A study was carried out to compare uncalibrated and calibrated RhoVol results to densimetric and size data obtained using traditional zinc chloride float-sink procedures, for three different coal samples in the size range 3 mm to 8 mm. The results indicate that the RhoVol can be used to provide simple, rapid and safe size-by-washability information for coal, provided proper pre-calibration is done, mainly to account for the effects of particle porosity in the density determination. Keywords: Coal washability determination, RhoVol, densimetric curve

Jan 1, 2020

By Huang Qiming

The CISDI-GreenEAF innovatively applies the top-side-chute for charging for improving the cold zone of electric-arc furnace (EAF) requiring preheating scrap. It can greatly reduce the operating power consumption during EAF melting by combined use of fume for preheating scrap. The enclosed charging mode and specially-designed structure contribute to less emission of dust and fume during charging while enhancing the metal yield. Thanks to the extraordinary fume temperature control at scrap preheating procedure and fume quenching technology as developed by CISDI, for restraining the regeneration of dioxin.

Oct 30, 2017

By C. J. Clayton, A. J. Haynes, D. A. Hickson, B. Thiele

The Meadowbank Gold Project, formerly owned by Cumberland Resources Ltd. and currently owned by Agnico Mines Ltd., is currently being developed approximately 70 km north of Baker Lake, Nunavut, in the eastern Canadian Arctic region. The Meadowbank Gold Project currently consists of a series of gold-bearing deposits within relatively close proximity to one another, which are planned to be mined primarily as a truck-and-shovel open pit operation using conventional gold milling and extraction. The mining plan indicates that approximately 20 million tonnes of ore will be mined over a mine life of eight to ten years. The operation will generate approximately 160 million tonnes of mine waste rock and about 20 million tonnes of tailings. The site is located in an area of continuous permafrost with mean annual average air temperature of -11°C and average annual precipitation in the range of 100 to 200 mm. Lakes cover a large portion of the site, including some of the ore deposits. The location of the site and the physical environment pose challenges to development. This paper presents some of the designs considered to effectively manage and utilize the waste products of mining at the project. Note that volumes, tonnages, construction concepts, and data presented in this paper are accurate for the time of writing and are subject to change and modification as the project progresses, additional modelling is carried out, and additional data are obtained.

Jan 1, 2007

By N. B. Aughenbaugh

Compacted clays are used as permeability barriers in many mineral engineering projects such as heap leaching, containment ponds, tailings disposal and earth dams. Source materials used for clay liners include a wide variety of sand, silt and clay admixtures that exhibit dramatically different engineering properties when densified. The permeability and plastic properties of fine-grained soils are reviewed with respect to the state of compaction as the water content varies. Be-cause they are weak in tension, compacted clays are susceptible to cracking when subjected to differential flexural movements. Designs of compacted clay liners must include an evaluation of their flexibility which is the ability of a fine-grain soil to bend plastically without cracking. This paper will also discuss the importance of flexibility with respect to soil types, compaction effort, failure mechanism and testing evaluation to the performance of clay liners in preventing seepage of pollutants from a containment site.

Jan 1, 1990