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By K H. Esbensen

Sampling of grain, animal feeds (solid and liquid) including important mineral mixtures in the Danish agricultural sector is subject to an ongoing investigation with the objective of improving existing (suboptimal) sampling procedures. Results from the first six months are presented here; the project will continue for two more years and will include international collaborators (Australia and Canada). The Danish authorities have instituted a system of control analysis, which contains a set of mandated sampling and analysis methods. From a preliminary survey it was concluded that in fact all of the existing sampling procedures are not optimised in the light of Pierre GyÆs Theory of Sampling (TOS).

Jan 1, 2005

High pressure grinding roll (HPGR) technology is used in an increasingly diverse range of applications, predominantly iron ore, gold and diamonds. KHD Humboldt Wedag HPGRs are applied world-wide, and consistently prove to be well designed and reliable operating units, with their performance meeting the pre-set standards. This publication summarizes some of the features and experiences for recent applications in treatment of copper ore, coarse iron ore, and gold ore. Summary data of roll surface wear life and operating data are given, together with operational observations. In addition, effects of feed segregation and truncated feed are discussed, as well as the implications of a product recycle flow sheet.

Jan 1, 2012

By Yunqing Zhang

Weak shales refer to those with lower strength, thinly- laminated structure, sensitivity to moisture and weathering as well as significant time dependent behavior. It has been said that many future coal reserves with good quality have weak immediate roofs. Therefore their geo-mechanical properties and behavior must be known before an appropriate support plan can be designed. In this study, four types of shales collected from underground coal mines were tested in the laboratory. Their modes of failures in underground were observed and correlated with their lab behavior. The failure mechanisms of thinly-laminated weak shales were analyzed by the means of numerical modeling.

Jan 1, 2004

By Valentine Garfias

THE various phases of the Mexican oil industry have received so much publicity that there is little to add to the discussion of present and future production, extent and importance of prospective fields, and status of petroleum legislation, to mention but a few of the angles of the Mexican oil problem. However, out of this wealth of information, which is generally of contradictory nature, the average petroleum man is at a loss to know something definite regarding the various questions involved so, keeping the foregoing in mind, it has been the writer's aim to record in a concise form the most reliable and up-to-date information regarding the salient features of the Mexican oil situation. PRESENT STATUS OF MEXICAN OIL INDUSTRY Production During 1921 The Mexican oil fields, during 1921, produced in round numbers 203,000,000 bbl. of which 176,000,000 bbl., or 86 per cent., were exported, the bulk of -these exports, or about 73.3 per cent., going to the United States. The Mexican exports were divided by grades as follows: Light crude, 47.0 per cent.; heavy crude, 22.0 per cent.; tops, 3.5 per cent.; fuel oil from light crude, 24.0 per cent. The balance, or 3 1/2 per cent., includes the bunker fuel shipments and the coastwise trade in Mexico, which is not classified as to grades. The figures show that, in importance, the light-oil fields from about 755 per cent. of the Mexican petroleum industry.

Jan 4, 1922

By C McGuire, W Harris, S Arsenault, D Witow, B Rogers

Mining deep orebodies is increasingly becoming the norm as the ‘easy’ orebodies are depleted. Deep ore mining requires significant ventilation and cooling infrastructure to not only meet regulatory requirements for air quality but also to achieve acceptable workplace temperatures with the higher strata rock temperatures and increased auto-compression. At the same time, advances in battery equipment technology are turning the possibility of a battery powered fleet into reality. The switch from a diesel fleet to a battery powered fleet offers several positive opportunities for the design and operation of a deep mine.The potential to reduce ventilation and cooling requirements due to battery powered equipment results in significant cost savings for mine development and infrastructure. Battery powered fleets are not subject to the same dilution requirements associated with diesel fleets thus allowing lower ventilation rates. At the low ventilation volumes possible with a battery powered fleet, surface refrigeration plants are limited with respect to the amount of cooling that can be delivered to the workface. Considerations for calculating the optimum air flow and cooling requirements are presented. Considerations for locating the refrigeration plant are also discussed. This paper presents these opportunities and considerations; including a case study comparing the ventilation and cooling system design with a diesel fleet versus battery fleet for a planned mine in Northern Ontario, Canada.CITATION:Harris, W, Arsenault, S, McGuire, C, Rogers, B and Witow, D, 2017. Diesel to electric – creating a positive paradigm in underground ventilation and cooling, in Proceedings Australian Mine Vent Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By R. L. Andelin, J. D. Knight, M. Kahn

Self-diffusion in single-crystal tungsten and diffusion of rhenium tracer in single-crystal tungsten have been measured over the temperature range 2660° to 3230°C by direct sectioning and radio-chemical analysis of W185 and Re183 and Re184 tracers. The initial radioactive layer was produced on the diffusion specimens by bombardment with 9.0-mev deuterons. Diffusion heating of the samples in high vacuum was accomplished by induction heating. Temperatures were measured by optical pyrometry, and the system was calibrated ALTHOUGH a considerable body of experimental information has been accumulated on self-diffusion in solids, the major part of the detailed work has by reference to the melting points of tantalum (2996°C), molybdenum (2620°C), niobium (2468°C), and rhodium (1966°C). The diffusion coefficients for the two systems, obtained by least-squares analyses of the data, are well-represented by the equations thus far dealt with relatively low-melting systems. Diffusion studies on the high-melting elements niobium,1 tantalum,2,3 and tungsten4'5 have been limited to polycrystalline material, for which data interpretation and theoretical analysis are sometimes difficult. Only recently, a study has been made with single-crystal molybdenum.6 The present work deals with the measurement of self-diffusion in single-crystal tungsten at temperatures approaching the melting point (3410°c).7 Since the method chosen for producing the radioactive tracer layer-bombardment with deuterons—produced detectable isotopes of rhenium as well as of tungsten, the diffusion of rhenium was measured also.

Jan 1, 1965

By J. E. Johnson

The subject of blast-furnace slag is one which has had much consideration, particularly from the scientific standpoint, and several years ago technical literature contained many learned discussions on the oxygen-ratio of the acids and the bases, all on the assumption that acids and bases must be present in a ratio depending on molecular weight and chemical valency. Much work has also been don.e, sometimes in conjunction with the former, on the total heat and the temperature of initial fusion or softening of various slags. A wider knowledge of the blast-furnace now enables us to say that for practical purposes this work has been of almost no value. It is now generally admitted that on,the physical side the important point of a given slag is neither its total heat of fusion nor its softening-point, but its free-running temperature, since this is the critical temperature of the furnace. This temperature bears no definite relation to the softening-temperature, as determined by Seger cones, for instance, because some slags melt relatively like ice, with a very short viscous-range, while others melt relatively like tar, with a very long viscous-range. In one the difference between the softening- and the free-running temperature may be very small, as little as 100° F., while in another this difference may easily be 200' or 300°. The importance of this difference is so great in practice as to destroy completely the value of exhaustive investigations, even such as those of 0. Boudouard, published a few years ago.'

Jan 1, 1913

By A. R. Hekmat

Hypereutectic Al-Si alloys are used in applications that require high resistance to wear and corrosion, hardness and low coefficient of thermal expansion, To maximize the properties of these alloys, semi-solid processing can be utilized to modify the solidification structure of the primary silicon crystals as well as to reduce microsegregation and porosity, The transformation and spheroidization of primary Si crystals by shearing in the semi-solid state are not fully understood as they precipitate in the presence of other alloy phases, The objective of the present work is the determination the rheological characteristics of A390 (Al-17%Si-4,5%Cu-0.5%Mg) alloy using a Couette type (Haake RV12) viscometer and examining the microstructural evolution during continuous cooling and isothermal shear rate experiments, The effect of shear rate, solid fraction (temperature) and morphological evolution of the silicon crystals are investigated.

Jan 1, 2005

By W. W. Weigel

In "Mine Drainage, Southeast Missouri Lead District," Trans. AIME, (1943) 153, 74-81, the general water conditions in the lead mines of Southeast Missouri were described. Some comments developed from the experience of time and some further

Jan 1, 1949

By Carle R. Hayward

THOUGH recent months have seen a rapid decline in lead-smelting activity and consequent uncertainty as to the future, the first half of the year showed progress in keeping with similar activity in other metals. Demand for scrap increased and various lead-bearing materials found their way to plants producing secondary lead. Some of these materials introduced complications into normal smelting procedure and were the cause of many conferences among plant officials attempting to find the most satisfactory method of treatment. If a blast furnace is to do itself justice it must be run with an open charge. Troubles inevitably result when materials are added to a charge which tighten it up and pre- vent free burning of the coke and con- sequent rapid smelting with a clean hearth This fact has long been recognized by plants producing primary lead, but only recently only it received the attention it deserves.

Jan 1, 1938

By Y. Kurokawa, R. Kurosawa, I. Iwata, I. Fukuoka, N. Sugita

INTRODUCTION The Ningyo-toge Mine is located in the western part of Honshu, about 800 km from Tokyo. Since the discovery of uranium ore deposit at Ningyo-toge in 1955, different kinds of mining and milling tests have been carried out. A new pilot plant of milling and UF6 conversion is also being under construction. Operations are scheduled to start by the end of this year. In 1979, the uranium enrichment pilot plant was constructed at Ningyo-toge and test operations have started. Thus, the Ningyo-toge area is assigned to undertake the Research and Development of the upstream of the nuclear fuel cycle in Japan. PNC has been strengthening its security measures more than ever. This paper will focus on the disposal of wasted material, especially on the disposal of heap leaching residue, in Japan. URANIUM ORE DEPOSITS The uranium of the Ningyo-toge Mine is characterized genetically by epigenetic sedimentary type deposits. They occur in the host rock of Neogene tertiary fluviatile conglomerates and sandstones which unconformably overlies the Mesozoic-Palaeogene granitic basement covered with lucustrine deposits and volcanic ejecta. More than 12 deposits have been found over the area of approximately 160 km2, and distribution of the deposits are strongly controlled by the so-called channel structure, probably remnants of paleo-streams on the denudation surface of the underlying grantic basement. Each ore body has different shape and dimension respectively, but about 2-3 meters thickness with the average grade of 0.05-0.2% U308 is common feature of the ore bodies. The ore is soft and loose, and it is composed of common rock forming minerals of allogenic origin and their altered products. The chemical composition of the ore depends on the constituents of the country rocks or the pebbles. A primary mineral, ningyoite and secondary mineral, autunite are major ore minerals, although three primary tetravalent minerals and thirteen secondary hexavalent minerals have also been detected. MINING EXPERIMENT Since 1959, various types of underground mining tests have been carried out at Ningyo-toge Mine. The room and pillar method was safe and simple, although the uranium ore recovery was below 70%. After experiment of the retreating long-wall method and slicing mining method, it was found that the modified long wall method was the most appropriate for the underground mining of the Ningyo-toge uranium deposits. This method was completed successfully to increase efficiency up to 2 or 3 times, as compared to conventional methods. MILLING EXPERIMENT In 1964, a small test mill was constructed at Ningyo-toge, and a milling experiment using the Ningyo-toge uranium ore was started. Re-modelling of equipments and improvement of the process lead to the establishment of the technique of the so-called wet process, and produce UF4 directly from the ore. The flow diagram is shown in Fig. 1.

Jan 1, 1981

By Chris Searing

An underground room-and-pillar limestone mine in Western Missouri acquired a new primary crusher, physically larger in every dimension than the unit it replaced. Due to the space constraints within the mine, resetting the truck dump and feeder to account for the larger crusher was unfeasible. Mine management determined the most practical solution was to increase the available area for the new crusher via blasting. Fitting the new crusher into the existing area required the removal of 6 feet (1.83m) of limestone from the original floor grade. Blast parameters had to be designed to effectively break this shallow depth of rock while controlling movement to avoid contacting the mine back 23 feet (7.01m) overhead, an apron feeder 13 feet (3.96m) above the southern extent of the area, and the original crusher which was still in place 15 feet (4.57m) from the first pattern. Additionally, work needed to be completed within an aggressive schedule set forth by the mine, allowing little room for delay or error. This paper will examine the efforts taken to safely and effectively blast the rock while protecting nearby equipment and integrity of the mine back. Subjects covered will include blast design, adjustments made to account for drilling and equipment-related constraints, and how seemingly small changes in load parameters can significantly impact performance with small-diameter blast design.

Feb 6, 2023

By John W. Adams, W. D. Bensema, Motohisa Kanda

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating coal mine, Robena No. 4, located near Waynesburg, Pennsylvania. One technique measures noise over the entire electromagnetic spectrum of interest for brief tine periods. With present instrumentation, the spectrum can be covered from 40 Hz to 400 kHz. It is recorded using broad-band analog magnetic tape, and the noise data are later transformed to give spectral plots. The other technique records noise envelopes at several discrete frequencies for a sufficient amount of tine to provide amplitude probability distributions. The specific measured results are given in a number of spectral plots and amplitude probability distribution plots. The general results are that at frequencies below 10 kHz, power line noise within the mine is severe. Impulsive noise is severe near arcing trolleys, and at lower frequencies near any transmission line. Carrier trolley phone signals and harmonics are strong throughout the mine whenever the trolley phone is in operation. Additional information beyond that included in this report may be obtained from the authors, who are with the Electromagnetics Division of the National Bureau of Standards.

Jan 4, 1974

By Mario L. Villa

During 1938, oil activities in the Argentine Republic showed a favorable balance due to the increase in crude-oil production, the incorpora- tion of new producing areas and the discovery of deeper productive horizons. Drilling was as follows:

Jan 1, 1939

By Mario L. Villa

During 1938, oil activities in the Argentine Republic showed a favorable balance due to the increase in crude-oil production, the incorpora- tion of new producing areas and the discovery of deeper productive horizons. Drilling was as follows:

Jan 1, 1939

By M J. Davies, R S. Davies

Despite increased expenditure, the global discovery rate of world-class ore deposits has been in decline for over a decade (Schodde, 2017). Mineral exploration has traditionally followed an empirical approach, searching for evidence of mineralisation upon the surface of the planet, then drilling to define the extent of an ore body beneath the surface. As outcropping deposits in well-defined areas are depleted, there is a need for exploration to extend to less well-explored search spaces. One popular new frontier is exploration at greater depths beneath the Earth's surface. However, exploring for deep deposits with limited surficial evidence requires the implementation of predictive targeting methodologies (Hronsky, 2011; McCuaig & Hronsky, 2014). The Mineral Systems Concept (Hronsky & Groves, 2008; McCuaig et al., 2010) provides a framework for predictive exploration targeting. Ore deposit formation is recognised to be a focused mineralising event. These events represent self-organising critical systems and are underpinned by the interaction of complex, non-linear processes. Through the collection and analysis of datasets that map mineralising processes, it may be possible to predict the size and location of resultant ore bodies. CITATION: Davies, M J and Davies, R S, 2018. Beyond below-ground geological complexity: Developing adaptive expertise in exploration decision-making, in Proceedings Complex Orebodies Conference 2018, pp 95–98 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By J. Philip Neal

Feldspar is no example of special mineralization in isolated spots: it can usually be found within a mile or so of almost anywhere. Along with silica sand, it is a major part of our world's total mineral composition. This fact imparts to it an economic status different from a sulfide ore, or potash, or phosphate. While every feldspathic "stringer" does not possess economic potential, the generous distribution does yield a high statistical frequency of good feldspar ore bodies: the adjective "good" being subject to some flexibility of interpretation. The strong chemical bonds of this alkali aluminum silicate give it certain use advantages, but under present technology its individual elements cannot practically be separated to create aluminum, potassium, sodium, silicon - or their oxides. Its present uses rely upon chemical inertness - as in fillers; and on its physical melting characteristics and their effect in glass, enamel, or ceramics.

Jan 1, 1973

By J. Chipman, J. C. Fulton

BECAUSE of the great importance of the ternary system Fe-C-Si in ferrous metallurgy a considerable amount of attention has been devoted to the phase relations, particularly those occurring in the solid state.' The information on graphite solubility

Jan 1, 1955

By L. J. Moore

Introduction Hydrometallurgical solvent extraction (SX) processes – featuring large quantities of combustible or flammable organic solvents - are common in the mining industry for recovering non-ferrous metals such as copper, nickel, cobalt, uranium, tungsten, iodine and lithium. Recent fire loss incidents and the widespread use of sub-grade tank farms and piping trenches, plastic piping, poor drainage, and closely spaced buildings demonstrate opportunities to improve the use of Inherent Safety (IS) in this industry. The mining industry has designed and constructed facilities with an emphasis on personnel safety, production efficiency and cost effectiveness. The use of IS to eliminate or minimize property fire exposures has not seen widespread practice. Lessons learned from the mainstream CPI have not been communicated or applied. As an example, copper SX plants have consistently used design of gravity flow as a cost and production-effective solution for transferring liquids and minerals through the process. In fact, Jergensen1 recommends to “utilize gravity to the fullest extent possible” in design of SX plants. This philosophy has been achieved by laying out SX plants with process equipment at different grade levels so that solutions can flow “downhill”. Because of the use of large quantities of flammable liquids and the potential for these liquids - if released – to flow unimpeded into other areas – gravity SX processes represent severe inherent fire consequences unless costly barriers, drainage and channeling are also provided. It appears that little thought has been given to the fire protection consequences and challenges of this design feature during the evolution of SX plants and most copper SX plants constructed today use some form of a sub-grade processing area (tank farm) and one-way gravity flow. While this layout is used to assure a cost effective operation it has resulted in significant exposures to high value production. The use of sub-grade production units is an inherently unsafe layout where flammable liquids are used and is a layout that would rarely if ever be used today by the mainstream CPI. Gravity-assist layout is only one example where copper SX plants have been designed and constructed without IS in mind. The use of combustible and frangible corrosion-resistant materials – such as glass, wood and plastic - for flammable liquid storage, processing and piping systems has significantly increased the hazards of these facilities. These materials of construction are not rigorous and allow for rapid failure and release of flammable contents during fire exposure. The use of combustible or frangible systems to handle or transport flammable liquids is not a practice seen today in the CPI.

Jan 1, 2006

By Schoeman L., K. C. Sole

Evaluation and measurement of the influence of changes in conditions and electrolyte composition during early stages of a growing metal electrodeposit are crucial to predict changes in developing morphology. A galvanodynamic polarization technique was developed to reliably measure overpotentials for nickel electrodeposition from sulfate electrolyte. The validity of these polarization parameters as indicators of the relationships between changes in the electrolyte and resulting deposit morphology was evaluated for electrolytes of varying composition. Findings indicate that nucleation and plating overpotentials measured by the described technique can be used as indicative tools for monitoring, evaluating and ultimately improving control of the electrodeposition of nickel from sulfate electrolytes. The results predict that nickel deposits of desirable quality and morphology are obtained when plating overpotentials are higher than 700 mV vs. Ag/AgCl and nucleation overpotential is less negative than plating overpotential.

Jan 1, 2017