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By Detlef Sulzer, Winfried Rosenstock

"At the end of this century a great breakthrough in the field of blasting technology is finally going tobecome reality. That, in the true sense of the word, is the long expected and desired “HighTechnology Blasting”. So far trials have been carried out in Australia, Africa and Europe with remarkable results, that have been predicted by the authors. As a result, significant reductions of explosives and drilling expenditure are emerging for the future."

Jan 1, 1999

By Alan Bauer

In recent years there has been increasing interest in employing the technique of explosive casting in strip mines. Explosive casting, applied to dragline mining, describes the procedure whereby the overburden is horizontally displaced by blasting causing a portion of the material to be thrown into the previously mined cut. Therefore, it is not necessary to subsequently excavate this waste with the stripping equipment. In addition, allowing the overburden unrestricted movement during the blast most often results in improved fragmentation and enhanced machine productivity. The method is receiving attention because the capital and maintenance costs of stripping equipment has risen rapidly in relation to explosives costs. Improved productivity is necessary to maintain unit costs at an acceptable level.

Jan 1, 1983

By Numan Elmas

Barite deposits located in Dinek and surrounding region have important economic features with their large reserve capacity for Turkey. The objective of this study is to elucidate geological and depositional characteristics in terms of. site investigation and chemical analysis. In order to do this, geological area of about 300 km2 was examined and detailed geological map was constructed. It was observed that Barite mineralization in these deposits was occurred in carbonate and pelitic rocks of Lower Cambrian-Lower Ordovician. Deposits were exposed to advanced diagenesis regional metamorphism and tectonics that rotated and deformed the barites; therefore, barites shows secondary veins, brecciate and fracturing structure. Even though, a few light isotope values of barites may suggest hydrothermal and exhalative sedimentary characteristics or possible mixing with magmatic fluids, generally heavy isotope values indicate that the sulfate ions were supplied from coeval seawater and, many of sedimentary features and petrological, geochemical characters support dominantly sedimentary origin.

Jan 1, 2005

By A. Knoll, J. W. Beck, W. C. Brice, E. K. Lehmann

A cooperative study was undertaken in a neutral atmosphere by representatives of the environmental community, the mining industry and state government to identify and resolve environmental issues associated with base and precious metal mining before a commercial mining development is announced. The study included testing Minnesota's as-yet-untried nonferrous mining regulatory program using three hypothetical mining developments sited in environmentally sensitive areas where future mining could occur. Results include identification of critical paths for regulatory decision making, identification of particularly sensitive environmental issues that mill need continued deliberation before resolution and characterization of data necessary for environmental review and permitting decisions.

Jan 1, 1992

An outline of the circumstances giving rise to the current Commonwealth-States con- flict in relation to offshore mineral explor- ation and production is set out, together with an analysis of the Seas and Submerged Lands Act 1973. The bases of the claims by the Commonwealth and the States in this regard are discussed with relation to the territorial sea and the continental shelf.

Jan 1, 1974

By S. Markstrom

The Boliden AITIK copper mine is located 100 kilometres north of the Arctic Circle in northern Sweden. A pre-feasibility study was conducted in 2005 with the aim of increasing the capacity of the existing processing plant. After analysis, options to upgrade the existing plant were abandoned in favour of building a new processing plant, with higher capacity and therefore greater profitability. A new plant could be designed with greater flexibility to make potential future expansions easier. A feasibility study for a new 36 Mt/y processing plant including fully AG grinding circuits and flotation was completed in 2006. The project was approved by the Boliden board shortly thereafter. Construction started in the beginning of 2007 and was completed during 2009. Commissioning of the new plant was undertaken in the first half of 2010. The grinding circuit consists of two lines with each line consisting of a 22.5 MW AG mill and a 10 MW Pebble mill in closed circuit with a spiral classifier. The nominal production level is 2 200 t/h for each grinding line. This paper presents the start-up and operation of the grinding circuit.

Jan 1, 2012

By T. Stergiou

An extensive research is being carried out on the shaft furnace operation in order to minimize down-times and reduce operational cost. The need to increase the scrap percentage on the charging mix, together with the need of cheaper spare parts has led to the investigation of alternative materials for the burner system on the shaft furnace. This system consists of a burner block and a flame holder. Traditionally these items are constructed either from SiC ? oxide bonded or SiC-nitride bonded. A lot of problems have been confronted over the past 8 years of operation. Usually, large cracks are formed on both flame holders and burner blocks. This resulted in leakage of combustion gases to the back of the lining and a quick erosion of it. Additionally, the burner blocks suffer from chemical erosion, due to the increased amount of scrap used in the charging mix and the presence of slag inside the furnace. Alternative materials such as stainless steel for the flame holder and alumina-chromia refractory for the burner block have been tested in terms of life-time and resistance on chemical erosion. Furthermore, additional changes have been made on the burner block design in order to alter the flame shape and improve the scrap melting operation.

Jan 1, 2007

By H. J. Wasson, E. B. Hopkins

Throughout 1928, production of oil from Venezuela steadily increased, and at the close of the year, the output was at the rate of nearly 400,000 bbl. a day. The total for the year was approximately 106,500,000 bbl., representing an increase of about 66 per cent. over the 63,000,000 bbl. produced in 1927. Venezuela now stands next to the United States as the second largest oil-producing country in the world; and there is abundant evidence to suggest that this relationship will endure for a number of years. Reserves were notably increased in the Lake shore fields, and the potential output of the Maracaibo Basin is much greater than the current production. In spite of this, the percentage of production increase was comparatively moderate, and the rate of this increase continued to fall off slightly, as has been the case for the last three years. This does not suggest that further annual increases in Venezuelan output will not materialize; only that the rate of these increases appears to be on the decline, and that with every succeeding year the future tendency will be in the direction of a stabilized level of output. The following table shows the production trend of the country since 1925: 1925 increase over 1924, 132 per cent. 1926 increase over 1925, 80 per cent. 1927 increase over 1926, 75 per cent. 1928 increase over 1927, 66 per cent. Many factors will work to prevent a reversal of this trend, but the principal ones are strong ownership in large-acreage units, and the probable indisposition of the world market to absorb a more rapidly increasing Venezuelan output at prices profitable to the producers. The distress oil element is not a factor in Venezuela; also, any unforeseen jump, such as results in the United States from the discovery of a Seminole or a deep sand at Long Beach, or Santa Fe Springs, is impossible in Venezuela, on account of lack of means for transporting a sudden surplus of oil, and the slowness with which additional transportation equipment in the form of shallow-draft tankers can be obtained.

Jan 1, 1929

By Y. Fukunaka, Y. Kondo, Z. Asaki, S. Nakashita

The pyrite smelting process in which about half amount of sulfur is recovered from pyrite by thermal decomposition in an oxygen-free high-temperature combustion gas flow in the flash smelting furnace is being conducted at Kokkola Works in Finland. A mathematical model of this process was developed, and the rates of thermal decomposition and fusion of suspended sulfide particles in the reaction shaft of furnace was calculated. This model is thought to be appropriate because of a fairly good coincidence of the calculated length of reaction zone with the shaft height of the furnace at Kokkola Works. The calculated reaction zone in which the thermal decomposition and fusion of sulfide particles occur becomes longer when pyrite particles of larger sizes are fed. The feeding rate of pyrite particles and the gas velocity at the nozzle exit are also the important operating factors. These two factors are closely related to the volume fraction and the residence time of suspended particles in the gas stream, and the optimal combined levels of these factors at which the length of reaction zone becomes minimal were obtained.

Jan 1, 1976

By Tangstadm Merete, Eli Ringdalen

"This paper presents an overview of results from The Norwegian Research Institution SINTEF and the Norwegian University of Science and Technology, NTNU regarding new and ongoing research in silicon production. The main studies are related to condensation of SiO gas and cavity formation. If SiO gas condensation is increased at the top of the furnace resulting in SiO content in the off-gas closer to equilibrium, the Si yield will be increased significantly. Experimental work, simulating a cavity under industrial conditions, has shown that the cavity grows downwards from one layer. Physical appearance of zones in industrial furnaces, and selected reactions in these, are discussed based on results from excavation of industrial furnaces and results from laboratory experiments. Experimental studies of reaction rates for the formation of SiO are presented. Quartz properties are demonstrated to vary between differing quartz types and the effect of this is discussed.Introduction Both the theoretical and industrial issues associated with the production of silicon are described in detail in the textbook written by Schei et al [1]. This book covers the knowledge of silicon production process up to 1998. Together with the work by Myrhaug [1] and by Aasly[2], this is the main basis for this paper. Recent and ongoing research at SINTEF and NTNU focusing on production of Si and SiO in the high temperature zone, dissociation of SiO and condensate and cavity formation will be discussed."

Jan 1, 2012

By T. S. Fuller

THE experiments described in this paper constitute the preliminary work of an investigation outlined to determine the combined effects of steam and temperature on the endurance properties of certain steels. Essentially of a fundamental nature, it was found necessary, in order to make the investigation comprehensive, to test materials treated to give a wide range of properties. The work reported deals chiefly with nickel steel with one series of tests including nitriding steel. Such a study involves numerous variables, and requires an endurance-testing machine of rather special design.

Jan 1, 1930

By B. M. O Harra, George M. Fowler, R.E. Illidge

The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north- eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). Early Operations Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. Production The a.ggregate ore production from the Tri-State district was recorded at intervals

Jan 1, 1943

By George M. Fowler, B. M. O Harra, R. E. Illidge

The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north- eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). Early Operations Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. Production The a.ggregate ore production from the Tri-State district was recorded at intervals

Jan 1, 1943

By V. Jiricny

The novel spouted-bed electrode (SBE) is a cathode system where copper is deposited at a high current density in a moving bed of copper particles. Preliminary results on the deposition of copper from acidic sulfate electrolytes using this novel cathode system were described during Copper '95 conference. Despite a high current density, the electrical energy consumption was equal to or lower than that in the conventional electrowinning. The present paper describes more investigations on SBE. The SBE consists of copper particles with approximately 1 mm diameter onto which copper is deposited from acidic sulfate electrolyte whose composition is similar to conventional electrowinning. Three types of anodes were used in conjunction with the spouted-bed cathode, namely, DSA anode for oxygen evolution, and two novel anodes. One anode is less expensive than DSA; however it showed much promise in energy consumption. At a superficial current density of 2200 A/m2, the energy consumption was around 1.0 kWh/kg copper. The research activities described in this paper were supported by BHP Copper.

Jan 1, 1999

By Zvonimir Jam?ek

In Rudarski Institut Ljubljana (RIL), i.e. Ljubljana Mining Institute, we have developed CADRIL, a smaller CAD package which purpose is to overcome the difficulties by introducing Computer Aided Design in our mines. Program CADRIL is a graphics shell for several computer applications in mining. With the basic version of CADRIL all 2D working maps for daily use can be produced. Inserting different program blocks into CADRIL we get versions MAPRIL, TAHRIL, SECRIL and so on. The main purpose of all versions is graphics design. The main and most innovative feature of CADRIL is the screen four-word command menu. Not having pull-down or tablet menus is the speciality of this program. CADRIL contains 500 achievable commands. Each of them can be composed by choosing two to four expressions stored and shown in a specific four- column menu, sorted as objects functions, parameters and modes. Thus all commands are immediately accessible. As a result of its plainness and adaptability to the present working methods of mining engineers, CADRIL quickly attained a good reputation in our mines.

Jan 1, 1992

By R. G. Lett

Gaseous products resulting from rapid pyrolysis of coal and coal/inhibitor mixture's by a ruby laser and a flash-tube were monitored on-line by time-of-flight mass spectrometry. The distribution of stable gases from the coal is not Greatly influenced by the addition of small quantities of powdered flame inhibitors. Preliminary studies of the reaction of elementary radicals with coal and coal/inhibitor mixtures are described. The different types of experiments are discussed with regard to possible modification and application to studies of flame inhibitor action.

Jan 1, 1973

By Percival Roberts

It may seem necessary to offer an apology for presenting for consideration a process which is conspicuous by its absence in the literature of the Institute, and which may be thought by some to belong to the past in metallurgy, and to have been already superseded. But the large capital invested in puddling calls for a careful consideration of the question whether the time has certainly arrived when the puddling furnace must be replaced by the converter and open-hearth furnace. May there not still be a place for puddled iron alongside of molten iron and steel, and is not the improvement of the puddling process itself worthy the attention of engineers equally with the Bessemer and open-hearth processes? The changes involved in the conversion of pig iron into wrought iron are well understood and need only be briefly alluded to. The patent of Henry Cort bears the date of 1784. Since that time * the improvements in the process have mainly consisted in the replacement of sand by iron bottoms by Samuel Baldwyn Rogers in 1818, and the still more recent substitution of iron oxide for the refractory materials used for the rides and bridge of the hearth, which distinguishes the wet or boiling process from the dry or pnddling process. Chemically, the process consists in the removal of the metalloids from the pig iron, a result effected mainly by the iron oxide. Silicon is first oxidized, then the phosphorus, and finally the carbon. The silicic and phosphoric acids produced pass into the cinder and the carbonic oxide burns as it escapes from the bath of metal. It is interesting in this connection to note the effect of temperature on the removal of the phosphorus from the iron. As is well known, no phosphorus is eliminated under the oxidizing influences prevailing in the Bessemer converter, while from 70 to 80 per cent. is removed in puddling. But we find, if in working cold short irons

Jan 1, 1880

By Charles Miller

Natural carbon dioxide has recently been exploited in the United States in consequence of oil and gas developments in the Western States and the growing demand by transcontinental and transoceanic shippers for solid carbon dioxide. The discovery by drilling of commercial deposits resulted in consideration of its geographic and geologic distribution and occurrence. Its wide distribution in nature is evidenced by its occurrence in the atmosphere, hydrosphere and lithosphere. The question of origin of carbon dioxide involves consideration of theories similar to those concerning natural hydrocarbons, although available evidence favors an inorganic rather than an organic source. Areas favorable to development of commercial production appear to be those in proximity to igneous rocks or in the vicinity of decadent volcanic activity, where, it has long been known, the gas is evolved either free or dissolved in the waters of fumaroles, geysers or mud pots. Structure contour maps are presented showing the Wagon Mound anticline in New Mcxico and the Farnham anticline, Utah. A well drilled on the latter supplies gas to a 20-ton plant manufacturing solid curbon dioxide at Wellington, Utah, on the Denver and Rio Grande R.R., whence it is shipped to surrounding territory and to the West Coast. Before funds are invested in a plant for the manufacture of liquid or solid carbon dioxide, whether supplied by wells or springs, an effort to ascertain the volume of gas available is advisable. The use of present methods of estimation of gas reserves with modifications to account for the quantity absorbed by any water present in the producing formation is recommended. The Farnham anticline is used as an example and computations are made of the probable volume of gas originally present in the structure. No attempt was made to compute reserves in the Niland area, California, for the reason that in such areas it is believed the volume is indeterminate. Introduction Carbon dioxide, in liquid and solid form, has found a wide variety of uses other than its primary application in carbonating beverages. It is now used in more than 40 different ways, ranging from cooling or freezing to use in gas or liquid form for mechanical purposes, chemical industry, explosive, fire extinction, and tire manufacturing. Undoubtedly the chief supply of carbon dioxide is obtained from industrial plants or artificial sources and until recently natural deposits of the gas have received little consideration. Few will question the utility and perhaps dependability of artificial sources, which possess the advantage over

Jan 1, 1938

By Charles Miller

Natural carbon dioxide has recently been exploited in the United States in consequence of oil and gas developments in the Western States and the growing demand by transcontinental and transoceanic shippers for solid carbon dioxide. The discovery by drilling of commercial deposits resulted in consideration of its geographic and geologic distribution and occurrence. Its wide distribution in nature is evidenced by its occurrence in the atmosphere, hydrosphere and lithosphere. The question of origin of carbon dioxide involves consideration of theories similar to those concerning natural hydrocarbons, although available evidence favors an inorganic rather than an organic source. Areas favorable to development of commercial production appear to be those in proximity to igneous rocks or in the vicinity of decadent volcanic activity, where, it has long been known, the gas is evolved either free or dissolved in the waters of fumaroles, geysers or mud pots. Structure contour maps are presented showing the Wagon Mound anticline in New Mcxico and the Farnham anticline, Utah. A well drilled on the latter supplies gas to a 20-ton plant manufacturing solid curbon dioxide at Wellington, Utah, on the Denver and Rio Grande R.R., whence it is shipped to surrounding territory and to the West Coast. Before funds are invested in a plant for the manufacture of liquid or solid carbon dioxide, whether supplied by wells or springs, an effort to ascertain the volume of gas available is advisable. The use of present methods of estimation of gas reserves with modifications to account for the quantity absorbed by any water present in the producing formation is recommended. The Farnham anticline is used as an example and computations are made of the probable volume of gas originally present in the structure. No attempt was made to compute reserves in the Niland area, California, for the reason that in such areas it is believed the volume is indeterminate. Introduction Carbon dioxide, in liquid and solid form, has found a wide variety of uses other than its primary application in carbonating beverages. It is now used in more than 40 different ways, ranging from cooling or freezing to use in gas or liquid form for mechanical purposes, chemical industry, explosive, fire extinction, and tire manufacturing. Undoubtedly the chief supply of carbon dioxide is obtained from industrial plants or artificial sources and until recently natural deposits of the gas have received little consideration. Few will question the utility and perhaps dependability of artificial sources, which possess the advantage over

Jan 1, 1938

By Robert L. Lappi

Eight interburden handling concepts are developed for multiple seam area mine stripping operations in central and western United States. They are based on data gathered and analyzed during field surveys, literature reviews and visits to state requlatory agencies in five states. It is concluded that improvement of reclamation practices through selective interburden handling techniques is possible at lower operating costs than currently incurred. Specific multiple seam mining systems are discussed in this report.

Jan 1, 1980