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By Carl Swartz

METALLURGISTS differ considerably in their opinions regarding the effect, if any, of small amounts of iron pyrites, or other iron compounds on zinc sulfide ores during the roasting operation. As a result, the literature on this subject expresses many conflicting ideas. The ore, previously crushed to pass through a one-millimeter screen, dries in the roasting kiln, losing water up to 200° to 300° C. At 150° C. iron pyrites begin to lose sulfur. As the temperature increases, while the ore is passing to the hotter part of the furnace, the sulfur burns to sulfur dioxide, leaving the metals as zinc oxide and ferric oxide. These two substances then interact to form zinc ferrite, a compound, yellow brown in, color, having the general characteristics of a spinet Like magnetite, another spinel, zinc ferrite is insoluble in alkalis and dilute acids. As a result, when leached with 10 per cent. sulfuric acid solution zinc values tied up in this compound remain behind. HISTORY In the electrolytic recovery of zinc from its ores, the roasted ores are usually leached with a 10 per cent. sulfuric acid solution. When the zinc ore contains iron pyrites as an impurity in an appreciable amount, the actual yield of metallic zinc is much lower than a theoretical calculation would indicate. Further, losses of zinc are, in a rough way, directly proportional to the amount of iron pyrites or other iron compounds present. When the iron is present in the ore in an isomorphous relation to the zinc, as in the case of a marmatite, a greater amount of zinc remains insoluble than when present as a true pyrite or marcasite. Work on the insoluble residues obtained from leaching of the calcines shows that the zinc lost is intimately tied up in this residue. Some investigators have suggested a definite compound, such as zinc ferrite, others merely a mixture of zinc and iron compounds.

Jan 1, 1927

By John L. Halls

Modern business practice dictates that in order to ensure the economic optimization of investment, the size of any investment venture must be such that every increment of capital invested in such a venture yields at least a corporate minimum acceptable rate of return. This practice is based on the premise that alternative investment opportunities capable of yielding the minimum corporate return are immediately available. If a mining corporation is to make the maximum use of its investment funds, any capital investment in a mining property must comply with the above practice. The most important parameter in estimating ore reserves is the cut-off grade which is used to separate material into ore or waste. The cut-off grade is calculated on the basis that material of cut-off grade produces sufficient revenue to cover the estimated costs of mining and processing through to sales, including depreciation and produce a pre-determined profit. Ore reserves so estimated are adequate for determining the magnitude of an orebody but do not provide a sound basis for determining plant size and therefore capital investment in a new property or for expansion consideration on an existing property. From a financial analysis of this one ore reserve it is impossible to ascertain whether each increment of capital investment is providing the minimum acceptable rate of return, Other difficulties associated with the calculation of a cut-off grade including the determination of depreciation and the amount of pre-determined profit to be included in the cut-off grade calculation are outlined in the text. The proposed solution to determine optimum ore reserves and plant size for new properties avoids the complication of calculating a cut-off grade by computing a series of ore inventories using arbitrarily selected cut-off grades. A comparison of the cash flows generated by production from such ore inventories using incremental financial analysis clearly indicates the ore reserve and plant size which will best serve the corporation's investment and metal production goals. Incremental financial analysis of a corporation's operating mines and prospects assists management in assessing the comparative expansion and investment possibilities of each property for increasing or maintaining metal production on a long term basis.

Jan 1, 1969

By J. J. Friel, E. S. Erickson

Dolomite-fluxed pellets of various compositions were made from magnetite concentrate, hematite concentrate and a concentrate containing a natural mixture of both. Physical properties and reduction test results were used to ascertain proper compositions and firing temperatures. These pellets were subjected to physical tests and to reduction tests. Petrographic and electron microprobe examinations were made to evaluate the effect of composition and fining on the phase assemblage. We interpreted our test results in terms of chemistry and microstructure and related these to properties. This approach enabled w to determine the composition best suited to each of the three concentrates. Compared with acid pellets, dolomite- fluxed pellets of the optimum compositions had similar physical properties but swelled less, softened at a higher temperature, and reduced faster and more completely.

Jan 1, 1983

By G. E. Viens, R. A. Campbell, G. N. Banks

A survey of the literature reveals wide differences in the procedures used in making iron ore pellets and in the properties of the pellets obtained. In this paper, the methods of production and the properties of pellets, as reported in the literature, are examined in an effort to determine what correlations exist between them. An attempt is also made to determine the levels of the properties of pellets which are considered acceptable and desirable in modern practice. M UCH has been written regarding the important changes which have been taking place recently in the iron ore industry. As the demand for ore has increased and the supply of direct-shipping ore has dwindled, tl1e problems associated with the utilization of lower grade ores ha\•e been intensely investigated and important advances in both beneficiation and agglomeration techniques have taken place. In particular, there has been a great deal of activity in connection with the pelletizing method of agglomeration. The superiority of pellets over raw ore has been demonstrated in blast furnace tests

Jan 1, 1962

By Alexandre Schultz Rizek

Esse projeto visou a substituição do sistema de controle instalado por um padrão RUSSULA, sistema esse que controla um laminador de barras e de rolos de 500.000 toneladas/ano na Usina Presidente Vargas da CSN em Volta Redonda, RJ/Brasil. Juntamente com o sistema de controle, RUSSULA forneceu um novo posto de operação para a cabine central, com novas telas de operação, sendo um posto “touch”. Equipado com controladores Siemens S7-400, IHM Wonderware InTouch, acionamentos ABB ACS800 e DCS800, o sistema se apresentava ineficaz, exigindo a otimização do processo, aumento de produtividade, diminuição de paradas, diminuição de perdas metálicas e maior confiabilidade no controle, o último através das ferramentas RUSSULA implementadas no software, como por exemplo detecção automática de sucata, controle de tração, controle de laço, rastreamento do material no laminador, otimização de corte das tesouras e barra fantasma.

Aug 17, 2017

The cables brought the news last spring that the Institute had lost by death one of its most distinguished foreign members, Hjalmar Sjogren of Stockholm. For thirty-one years, Professor Sjogren had been one of our number. He was elected in 1891, joining the Institute at the time he was in the United States, in attendance at the Fifth International Geological Congress, which was held in Washington in the late summer of that year. Professor Sjogren was once more in America in 1906 and again in 1913, and on both of those visits his friends in New York had the welcome opportunity of extending courtesies to him. He was thus well known to a wide circle in our membership. His keen interest in the geology of iron ores brought him in touch with the many Americans who have studied them and who have been active in the important productive districts which he visited. Our Transactions contain (Vol. XXXVIII) one very important paper of seventy pages on the Geological Relations of the Scandinavian Iron Ores, which he contributed. Sten Anders Hjalmar Sjogren, to give his full baptismal name, was born June 13, 1856, and was the son of Anton Sjogren, a mining engineer, at the time in charge of the iron mines at Persberg, in the east and west iron-ore belt of central Sweden, about 160 miles west from Stockholm. The Persberg orebodies yielded magnetite and specular hematite from schists, with which limestones. were interstratified as well as the peculiar Swedish rocks called "halleflinte." The mines were also well known to collectors and students of minerals. While Hjalmar Sjogren was yet a lad, his father was advanced to the superintendency of a number of famous mining localities in this same district of Wermland. Paisberg, famous for its native lead, was one; and two others, Langban and Nordmarken, were among the most prolific sources of interesting minerals in all Sweden. In several localities, the pre-Cambrian limestones had obviously experienced the recrystallizing influences of intrusive igneous rocks and had been charged with the so-called "contact" minerals, which have found their way to the museums of the world. Anton Sjogren, the father, was a keen mineralogist and Hjalmar, the son, grew up in a favorable environment for receiving training and enthusiasms of the same sort. One is not surprised, therefore, to find Hjalmar Sjogren, in the long run, turning to mineralogy and geology as his final career.

Jan 1, 1923

The cables brought the news last spring that the Institute had lost by death one of its most distinguished foreign members, Hjalmar Sjogren of Stockholm. For thirty-one years, Professor Sjogren had been one of our number. He was elected in 1891, joining the Institute at the time he was in the United States, in attendance at the Fifth International Geological Congress, which was held in Washington in the late summer of that year. Professor Sjogren was once more in America in 1906 and again in 1913, and on both of those visits his friends in New York had the welcome opportunity of extending courtesies to him. He was thus well known to a wide circle in our membership. His keen interest in the geology of iron ores brought him in touch with the many Americans who have studied them and who have been active in the important productive districts which he visited. Our Transactions contain (Vol. XXXVIII) one very important paper of seventy pages on the Geological Relations of the Scandinavian Iron Ores, which he contributed. Sten Anders Hjalmar Sjogren, to give his full baptismal name, was born June 13, 1856, and was the son of Anton Sjogren, a mining engineer, at the time in charge of the iron mines at Persberg, in the east and west iron-ore belt of central Sweden, about 160 miles west from Stockholm. The Persberg orebodies yielded magnetite and specular hematite from schists, with which limestones. were interstratified as well as the peculiar Swedish rocks called "halleflinte." The mines were also well known to collectors and students of minerals. While Hjalmar Sjogren was yet a lad, his father was advanced to the superintendency of a number of famous mining localities in this same district of Wermland. Paisberg, famous for its native lead, was one; and two others, Langban and Nordmarken, were among the most prolific sources of interesting minerals in all Sweden. In several localities, the pre-Cambrian limestones had obviously experienced the recrystallizing influences of intrusive igneous rocks and had been charged with the so-called "contact" minerals, which have found their way to the museums of the world. Anton Sjogren, the father, was a keen mineralogist and Hjalmar, the son, grew up in a favorable environment for receiving training and enthusiasms of the same sort. One is not surprised, therefore, to find Hjalmar Sjogren, in the long run, turning to mineralogy and geology as his final career.

Jan 1, 1923

By A Castillo, K Wiese, L Panduro Robles

For decades, organisations worldwide have been working to overcome challenges associated with new technology adoption while keeping up with rapid growth, development, and globalisation. In minerals processing, the challenges in developing and implementing solutions that contribute to the mining value chain are unique from other markets, as mining operations expect that world-class suppliers provide them solutions to gain a competitive advantage in their operation, production, performance as a financial asset, and as a long-term partner as we move into the future of mining. A simple shift in mindset is proven key to successful technology implementation. Change leaders must no longer think of their expertise in the area of application as their only responsibility; they must make a mental shift and see themselves in dual roles that strive to integrate the perspectives and needs of both developers and users. Successful change leaders must: (1) collaborate, seeking user involvement to ensure fit between product and operational needs, (2) demonstrate commitment to receive new technology, and (3) communicate to achieve an eventual shift of ownership from supplier to users that is seamless. Additionally, this strategy contributes to the mining value chain, as it allows developers and implementers to evaluate how change contributes to the asset’s position both within the company and in the commodities market. This paper will explain the shift in perspective for new technology implementation in detail and provide recommendations that operations can emulate, using examples of real challenges and lessons learned during a commissioning of the CYCLONEtrac™ Particle Size Tracking (PST) system at Cerro Verde’s C2 Concentrator. This concentrator has led technological change for plant optimisation, witnessed improved Net Metal Production (NMP), among other benefits with PST, the only technology in the market capable of providing real-time, online, and direct particle size measurement at the individual hydrocyclone level

Aug 24, 2022

By L. Semushkina

Next generation flotation agents of KSK series for the concentration of complex copper-lead ores and the new ferromagnetic nanosized depressor of galena are introduced in this work. The feature of the KSK flotation agents is that they exhibit both frother and collector properties. KSK-6 can successfully substitute the widely used in Kazakhstani industry reagent ?-80 at the reduced consumption of butyl xanthate by 30 %. The new ferromagnetic nanosized depressor of galena, besides a low consumption rate of 100 g/t, also makes possible to exclude sodium sulfite (3-4 kg/t) and ferrous sulfate (5-6 kg/t) from the separation process, and receive high metal grade concentrates. Keywords: complex copper-lead ore, flotation agent, concentration method, ferromagnetic nanosized depressor

Sep 1, 2012

By Basil B. Zavoico

PRODUCTION of crude it in the United States during 1939 totaled about 1.255,776,000 barrels, an average of 3,440,482 barrels per day, 3.41 per cent above the 1938 output of 1,214,355,000 barrels but 1.83 per cent below the record pro¬duction of 1,279,160,000 barrels, in 1937. However only the two-week shutdown of oil fields in the Southwestern States in August and September prevented the domestic crude production from establishing an all-time record in 1939. Demand for all petroleum products for the first ten months of 1939 showed an increase of 7.04 per cent over the similar period of 1938. Domestic demand for all petroleum products was particularly benefited by the increasing industrial activity, advancing 8.37 per cent above the like period of the preceding year equivalent to a volume increment of 256,810 barrels per day; with motor-fuel demand gaining 5.83 per cent and demand for all fuel oils gaining 12.15 per cent over the corresponding period of 1938. The export demand for the first ten months of 1939 was slightly below the export movements during the same period of 1938, declining 0.56 per cent. The European war was a major factor in 1939 for the petroleum industry in the United States, even if, at the end of the year, the war had not yet resulted in the expected large shipments to England and France.

Jan 1, 1940

By Louis H. Meece

The romance of the River lives on in the tales of Mark Twain; and many Americans still think of the Mississippi River in terms of the steamboats loaded with passengers, gamblers and cotton. Yet for many years, coal has been a major cargo on the American waterways. Currently, about 100 million tons a year of coal is handled in some part of its journey from mine to destination by barge. The bulk of this traffic has been on the Ohio River System and the Upper Mississippi River System in years past. Now we have a new entry. Over the past 10 years various movements of coal have developed down the Mississippi River to power plants at Memphis and along the Gulf Coast, and a small amount of metallurgical coal has moved down the Mississippi River for export to Japan since 1970. But in 1980 a brand new player came on the scene. 1980 was a momentous year for the American coal business. Historically, we have exported about 50 million tons a year of metallurgical coal to the world's steel mills. Just before and after World War I, we also had a fairly healthy export trade in steam coal; and again in the late forties, we supplied large amounts of coal to Europe until domestic production could recover from the ravages of World War II. But since the early fifties, the name of the export game has been metallurgical coal. Starting in the mid seventies, something began that was almost totally missed by the American coal industry; and that was the growth in the use of coal first in Europe and now in the Far East as a steam product and as an alternative to petroleum products. As these world coal markets began increasing, the U.S. at first was thought to be noncompetitive because ocean rates were still very low. For example, as recently as 1977, Australian coal could be moved all the way from Australia to the Gulf Coast for $12.50 per metric ton. Coal exporting countries were Poland, Australia and South Africa, except for the continuing exports of U.S. high quality metallurgical coal. But then came the second oil shock, and all of the sudden that $12.50 rate from Australia to the U.S. Gulf became $25.00. And then suddenly and almost unrecognized by the American industry, American coal was in fact competitive at overseas destinations because of the drastic change in trade patterns brought on by the doubling and tripling and quadrupling of bunker fuel prices for ships.

Jan 1, 1982

By AIME AIME

WITHOUT frills, but with an admirable program of technical papers and discussion, many opportunities for social contact, and all New York for a playground, the 142d Meeting of the Institute will make the Engineering Societies Building a lively place from Feb. 20 to 23. Prices are down, even in New York. Come and forget the depression listening to the stories of old friends. Hear at first hand what is going on in your professional world. The fare is varied, of wide appeal. The program on the opposite page has been arranged carefully to minimize conflicts between the subjects in which you are interested. If it is not possible to come for all four days, check over the sessions that are most important to you. No changes in the scheduling are likely.

Jan 1, 1933

By William T. Folwell

The Lucky Friday mine east of Mullan, Idaho, is an outstanding example of a property in the Coeur d’Alene district where a small and insignificant- appearing silver-lead-zinc vein at the surface has changed at depth into a large vein of great importance. The Lucky Friday vein has little if any surface expression and above the 1200 level the ore shoots are small and discontinuous. Between the 1200 level and 2450 level, the lowest developed level, the main ore shoot has shown remarkable improvement on each succeeding lower level, and today the mine is one of the major lead-silver producers in the Coeur d'Alene district. History: The Lucky Friday property is on the north side of the South Fork of the Coeur d'Alene River in sections 25, 26 and 35, T. 48 N., R. 5 E., Hunter mining district, Shoshone County, Idaho. This is about one mile east of the town of Mullan, which serves the eastern portion of the Coeur d'Alene district. The southern part of the property is crossed by a branch line of the Northern Pacific Ry. and by U. S. Highway 10. This highway is the principal road crossing the panhandle of Idaho and connects the district with Spokane, Wash., on the west and Missoula, Mont., on the east. The main portal and surface plant of the Lucky Friday mine is at an elevation of 3365 ft, only a short distance above the valley floor and a few hundred feet from U. S. Highway 10, so the mine is readily accessible for year-round operation.

Jan 12, 1958

By B. Dubé, R. Friedman, J. Oliver, R. Aubertin, M. Burson, G. Panneton, M. Hamilton, J. Ayer

"Abstract — The Detour Lake gold deposit is located within the northwestern limit of the Archean Abitibi Subprovince of the Superior Province. Mineralized zones are hosted by a sequence of pillowed and massive flows, hyaloclastite units, and altered ultramafic rocks, and are commonly oriented parallel to a series of high-strain zones that are co-planar to the regional-scale Sunday Lake Deformation Zone. Early in its kinematic history, the Sunday Lake Deformation Zone placed older (2.72 Ga) volcanic rocks of the Detour Lake Formation over younger (2.70 Ga) sedimentary rocks of the Caopatina assemblage. Gold mineralization is also parallel to the position of a laterally persistent siliceous rock unit, the 2.725 Ga ‘Chert Marker Horizon.’ The Chert Marker Horizon coincides with the boundary between the mafic-dominated upper Detour Lake Formation and the ultramafic-dominated lower Detour Lake Formation. Stratigraphic and geochronological data suggest that the Chert Marker Horizon is a deformed felsic volcaniclastic unit. At a cut-off of 0.6 g/t Au, the Detour Lake deposit contains 17.26 million ounces of Au within 445.9 million tonnes of rock grading 1.20 g/t Au. Gold occurs in shear-hosted and extensional vein arrays within rocks of the upper and lower Detour Lake Formation and within the Chert Marker Horizon. The Detour Lake deposit has many of the characteristics of a greenstone-hosted, quartz-carbonate vein deposit; its very large size may be attributed to large-scale rheological controls resulting in the formation of dilatant sites in permissive rock units. © 2012 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved."

Jan 1, 2012

By Gaifeng Xue, Lijun Lu, Honghui Fang, Jiannyang Hwang

"Steel slag has been stockpiled in many steel mills due to its poor performance in various construction related applications. Free lime in steel slag has been considered as a major barrier for its utilizations. Composite of steel slag and powders of granulated blast furnace slag have been found an excellent cementitious material for concrete. Portland cement is not required in this kind of concrete. Concretes with various amounts of steel slag and powders of granulated blast furnace slag additions have been investigated. Physical and chemical properties of the products were examined. High performance concrete can be obtained. Field testing of the concrete products was conducted for various applications, including buildings and pavements, and the results demonstrated the soundness of the concrete. Drill cores of field tested concrete, with ages up to 26 years, were examined for the microstructures under SEM.IntroductionIn the steel industry, a major source of the solid waste is steel slag. Steel slag has poor stability in construction applications. This is a major reason that only a small amount of steel slag has been utilized. Some of the reported applications include the land filling/creation in the sea, road base materials, soil treatment for acid neutralization and micronutrients supply, and sintering aid in the sintering plant of the steel industry [1].To solve the stability problem for using steel slag as construction materials, the common approach is to find a method capable of depressing or eliminating the expansion of steel slag. Free lime in steel slag is the major component that causes the expansion. Aging and hydration pretreatment of free lime in steel slag are the well known methods for increasing the steel slag stability. However, there has been limited success on these approaches due to that a large portion of free lime is locked in the grains during the pretreatment process."

Jan 1, 2012

By Hon-Yim Ko

The properties of coal from the Pittsburgh seam, procured from the Bruceton and Federal No. 2 Mines were found to be similar. Strength and stiffness properties of Beehive Mine coal were determined and the material found to be isotropic. Mechanical, index and geologic properties of roof and floor coal measure rocks from Beehive mines were measured and correlated. Analytic formulations are given for coal creep under uniaxial loading, while triaxial creep is being investigated. Results of testing of coal model structures are compared with predictions from using several material models.

Jan 1, 1976

By S. A. Willis

For over 150 years gypsum from Nova Scotia has been shipped via water to the United States east coast. The history of the movement has been one of continual improvements in quarrying, loading, and shipping. At the start, man-size rock quarried by hand auger and black powder was loaded into horse-drawn carts, hauled to the waterfront, and dumped into 100-ton sailing schooners. Last year the Canadian Gypsum Company completed the latest and most modern of these successive installations for the movement of this Nova Scotia product. The new system loads crushed gypsum into 11,600-ton vessels at Hantsport in two hours' time at high tide. At the head of the bay of Fundy are located vast deposits of gypsum. The tidal rise and fall of 45 feet twice a day, with its attendant swift currents, has always presented major navigation and shipping problems. When the tide is low, the Hantsport ship-loading pier is high and dry, with no water within 400 feet. Three hours later a large river has flooded in (running up hill) and large steamers can dock at the wharf. Before high water, the ship has been loaded and -there is a depth of 30 feet or more of water around the wharf. At high water, the ship sails away on the ebbing tide as the river runs in the other direction. Tides are caused by the gravitational attraction of the moon and sun on the ocean. When both celestial bodies are pulling together the 'spring tide' results, which means a 50-foot variation from high to low. This occurs at new and full moon. A week later, when the sun and moon work in opposition, the difference is only 32 feet between high and low water. The bay of Fundy, having a funnel shape (150 miles wide at mouth from Yarmouth to Portland, while the upper estuary at Hantsport is only one mile wide), builds up a tidal influence from 10 feet at the mouth to an average of 45 feet at Hantsport.

Jan 1, 1948

By Wei Victor Liu, Omer Faruk Ugurlu, Chengkai Fan, Bei Jiang

The accurate prediction of truck productivity plays a pivotal role in improving the efficiency and profitability of open-pit mining operations. However, predicting truck productivity is challenging owing to the complex nature of the working conditions of the mine site. This paper proposes a deep neural network model to overcome the challenge of predicting truck productivity in open-pit mines. The prediction model was built using eight variables and was optimized by considering different train-test split ratios, numbers of hidden layers and neurons, and activation functions. The proposed model's performance was evaluated using various metrics and was compared with other commonly used machine learning algorithms. According to the results, the proposed model outperformed traditional machine learning algorithms by achieving higher accuracy and lower error rates, with the best-performing model having four hidden layers with 70 neurons per layer and a scaled exponential linear unit activation function, resulting in a coefficient of determination value of 0.89. This demonstrates the potential of deep neural network models for predicting truck productivity in open-pit mine sites. Moreover, a single variable sensitivity analysis was conducted to investigate the impact of input variables on truck productivity. The results show that haul distance is the most influential variable for the prediction of truck productivity.

Feb 12, 2024

By R. Pipeleers

Recent experience has shown that all underground workplaces in the Campine Coalfield in Belgium will require controlled cooling within three years. Considering the socio-economic and legal importance of the climatic problems underground, IREA has undertaken studies in forecasting the climate of future workplaces, planning the necessary cooling equipment and optimizing efficiency in the existing cooling equipment. These studies are being carried out using the climate forecasting program of Bergbau-Forschung. So far, the German model has been obliged to utilize manually measured data from a few workplaces in the Campine. As the model does not fit very well with these measurements, it has been thought necessary to' develop a system of continuous data acquisition and transmission. This system is being tested in the Beringen mine of the N.V. Kempense Steenkollenmijnen. In the first part of this paper the digital tranmission system is described; in the second the sensors used to collect the necessary climatic data are presented, and in the third some results are given.

Jan 1, 1987

Heatings, fires and explosions in New South Wales (NSW) and Queensland coal mines since 1972, are reviewed. Geological and mine settings are outlined. Where available, gas analysis and critical decisions are discussed. This paper updates work by NSW Department of Mineral Resources (1995) and the Queensland Department of Mines and Energy in a report on fires and explosion in Queensland coal mines (Richardson and Ham, 1996). Incident data has important applications in terms of evidence-based risk assessment and identifying key issues to be integrated into competency based training programs. Predictive indicators are reviewed in terms of coal parameters in seams where the incidents occurred.

Jan 1, 2005