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By C. Mueller

Automation of mining operations is pushed by cost pressure and cyclical product prices. However, until now the different types of equipment were not able to communicate electronically with each other or with central computer systems. Therefore, the International Rock Excavation Data Exchange Standard (IREDES) was launched by major players in the industry. The task of this initiative is to define a ‘common electronic language’ for easy and standardized data exchange. As in other industries, this standard is expected to have significant impact on the use of automation in general and on the markets for third party components and software. The standard’s technical architecture is open and flexible for future applications. It consists of an ‘horizontal’ structure defining ‘Application Profiles’ for different types of data sets. An additional ‘vertical’ structure (‘Equipment Profiles’) implements equipment dependent definitions for each of the applicable Application Profiles. First profiles will be available for Drill Rigs. The standard bases on the XML language thus enabling easy data exchange with commercial databases. IREDES data sets may use storage media as well as networking infrastructures for information exchange. The IREDES work is carried out by the initiative members working jointly together in the IREDES work groups. It is open for participation of all interested organizations. First prototyping applications are expected to start during 2001, the first products may be available in the following year. Key words: Mine Automation; Machine Automation; Data Exchange; Rock Excavation; Standard; Remote Control; Teleoperation; Ethernet; TCP/IP; Internet Technology; Service; Quality Assurance; Control Centre;

Sep 1, 2001

By Anylmore M, Walker A, Fletcher A

Roasting of sulphide and sulph-arsenide gold ores produces unwanted emission of sulphur and arsenic oxides, and a less than complete recovery of gold. Pyrite loses sulphur and arsenopyrite loses arsenic at a useful rate at temperatures of 600¦C and above in an inert atmosphere. Sulphur and arsenic driven off can be condensed before entering the atmosphere. During the process, solid-solution gold redistributes itself on internal surfaces of the resulting iron sulphide. Two subsequent processing options may be used; direct cyanidation of the porous sulphide resulting from the anoxic pyrolysis, or a second-stage roast to oxidise the remaining iron sulphide. The first option may be viable under certain conditions of pyrolysis. The two-stage option has an environmental advantage over the traditional roast because it reduces oxide vapour emissions by 50 per cent. The second stage may provide nearly enough energy to sustain the entire process.

Jan 1, 1992

By John J. Egan

THE present list of problems relating to the physical chemistry of steelmaking has been prepared by the Committee on the Physical Chemistry of Steelmaking, from answers to a questionnaire Submitted to a number of metallurgists engaged in both industrial and educational work throughout the United States. The purpose of the project is to make available to research laboratories a list of problems, all reduced to their simplest terms, the solution of which would aid in creating a better understanding of the steelmaking process. It is not intended to restrict the problems to practical steelmaking. The list also includes the study of the properties, and their correlation, as well as the physical and chemical reactions, of all Substances that occur or that may be in any way associated with steelmaking operations, Such as metallic substances, refractories, nonmetallic inclusions, and the constituents of slags. Many of the problems can be carried out in university or other research laboratories. Others may be most successfully attacked by cooperation of the research men with the operating personnel. It is the Committee's earnest wish that this cooperation be fostered. It is requested that investigators who are working on any of the problems listed and who anticipate future publication of their results, notify the Secretary of the Committee that such investigation is in progress. Suggested additions to the present list are also requested. The Committee is undertaking to act as a clearing house for information regarding the topics in this field that are being actually studied. Interested persons are invited to correspond with the Secretary. I. Data involved in the state of equilibrium for the various systems (laboratory work, almost entirely). A. SPECIFIC HEATS, HEATS OF FORMATION, ENTROPIES AND FREE ENERGIES OF VARIOUS PURE ELEMENTS OR COMPOUNDS; ALSO CERTAIN TYPICAL SLAGS AND REFRACTORIES. I . Determination of specific heats and entropies of oxides, sulphides, nitrides, etc. over a wide temperature range. 2. Determination of free energies of oxides, sulphides, nitrides, etc. over a wide temperature range. 3. Determination of the heats of formation of the oxides, sulphides, nitrides, etc. 4. Determination of the thermodynamic properties of the more important mineralogical constituents of the basic open-hearth slags such as calcium silicates, calcium phosphates, calcium ferrites, manganese silicates, FeO and Fe2O3. 5. Determination of the specific heats of open-hearth slags, including liquid silicates, if possible.

Jan 1, 1941

By Hervé Le Bissonnais, Jean-Pierre Janin, Anne Bergère, Pierre Renier

"The most important impact on the environment of a tunnel excavation is the creation of surface settlements. Nowadays, the mechanized tunneling allows minimizing the settlements, applying a confinement pressure which counterbalances the ground de-confinement. It is thus essential to determine the correct amount of confinement pressure. In this paper, the authors present a 3D numerical study simulating the EPB-TBM excavation of a water tunnel, in the Flanders clays (north of France). Firstly, a simplified 3D simulation, based on the concept of instantaneous longitudinal settlement curve, was performed to predict the surface settlements for different values of heading confinement pressures. Secondly, the same pressures were tested by the EPB-TBM in a monitoring zone. The comparison between the prediction settlements and the measurements was very satisfactory and allowed validation of the numerical approach and the choice of the optimal confinement pressure value for a sensitive area of the project. INTRODUCTION The excavation of a tunnel can create displacements of the surrounding soil which may affect existing structures and generate unacceptable dysfunction. The development of the closed shield tunneling has permitted to reduce the volume loss generated around the excavation and consequently the surface settlements. In this case, as explained by different authors (Clough et al., 1985; Kastner et al., 1996; Mair and Taylor, 1997), the ground movements are influenced by the TBM works: the heading confinement pressure, the shield overcutting and conicity, the annular void grout injection parameters, the segment concrete lining rigidity, the consolidation of the grout. Hence, in the tunnel design, it is important to take into consideration these different processes of the excavation works to simulate correctly the tunneling process."

Jan 1, 2016

By Naj Aziz

n Australia, the common method of laboratory testing of bolt for load transfer capacity determination is by short encapsulation push testing. Some concerns are raised about the validity of the test methodology, as the method does not reflect on the actual load transfer characteristics of bolt in real field situation. Thus, laboratory testes were carried out to examine the load transfer mechanisms of bolts in both the push and pull conditions. Tests were conducted by shearing a short resin encapsulated bolt out of a cylindrical steel sleeve. Three types of bolts with different surface profile configurations were tested. The study was complemented with numerical simulation of the test methods. Irrespective of bolt type the average shear load and shear stress values were found to be greater in push test, and the displacement at peak shear load was greater in pull test. The average shear stifhess values were greater in push test. The numerical simulation of the bolts provided a clear understanding of the stresses and strains generated by different bolt profiles during both the pull and pull testing process, thus allowing a better appreciation of the load transfer mechanism process.

Jan 1, 2005

By Ali Akbar Mottahedi

Chromate conversion coating is a process for making a complex layer at the surface of zinc galvanized steel which makes the metal more resistant to corrosion, especially at marine atmosphere, and increases the adhesiveness of color. In this work the influences of various compositions on commercial zinc galvanized steel sheet to the color of chromate conversion coating has been investigated at normal temperature and the factors that affect the control and optimization of the process have been determined. A bath composition of 20 g/liter Cr203 and 10 g/liter NaOH and a dipping time of 50 seconds at room temperature (25-30°C) make a desirable color of chromate coating. A slow agitation at a constant pH of I (with additions of NaOH or H2SO4) assures a constant bath condition and develops the color. This kind of coating has more corrosion resistance and this bath condition and composition are also more economical.

Jan 1, 2003

By H. Sieber

Multilayer samples of tantalum and aluminum with the composition of Al-25Ta were prepared by cold rolling of elemental foils. The microstructure and phases were characterized by XRD, SEM and TEMISAED and the reactive phase formation was examined by DSC and DTA measurements in multilayer foils rolled for different deformation levels. The rolling procedure yields a decrease of the Ta particle size in the Al matrix and also results in the formation of a multilayer structure with a thickness of the elemental foils down to 200 nm in average. No phase formation is observed during the cold rolling procedure. While XRD and DSC measurements show no phase formation up to the melting of aluminum for samples rolled up to 40 F&R (fold and rolling) passes, in samples rolled for 50 or more F&R passes a first phase formation reaction yield an interfacial layer of TaAl3. Contrary to former studies in the investigated cold rolled Al- 25Ta multilayers the reaction starts at temperatures as low as about 340°C. The first stages of the reaction are associated with two exothermic maxima, that increase in amplitude and shift to lower temperatures with increasing number of F&R passes. At higher temperature the TaA13 reaction layer thickens very sluggishly and yields a third exothermic maxima at about 600°C. Isothermal DSC scans show the reaction is not finished for samples containing elemental particles larger than 1 pm after annealing at 550°C for 5h. In all the investigated samples no Al- Ta phase other than Tad3 was observed to grow for heat treatments up to 800°C. Multilayer samples heated up to 1400°C show a morphology consisting of small AITa2 particles embedded in a single phase TaA13 matrix. The multilayer microstructure and reaction product morphology are characterized by SEM and TEM investigations in cross-section and plan view geometry.

Jan 1, 1998

By D. Hnrrington

THE Dust Symposium was attended by approximately 100 persons, nearly all of whom remained from the starting hour (2 p. m.) until the use of the auditorium was demanded for another meeting at 5:30 p. in. In calling the meeting to order, D. Harrington made a few remarks as to the importance of the health dust problem in mining as well as in general industry and expressed gratification that the subject is now out in the open and that mining people are desirous of ascertaining the facts. B. F. Tillson acted as chairman of the meeting. The milling executive who desires to know what to do to prevent his workers from being unduly exposed to the dust hazard can get much out of the paper by D. E. Cummings, who has been doing much work in mines trying to keep -the dust in the air within safe limits. His recommendations indicate that the main protection of the worker in mines is by adequate ventilation, supplemented by the extensive use of water in drilling, as well as in water curtaining to condition air both in regard to dust content and to temperatures. Blasting was shown to be one of the chief causes for dust and it was recommended that whenever feasible all blasting should be delayed to the end of the working shift.

Jan 1, 1935

By S. J. Schatzel, J. D. Addis, V. Gangrade

In longwall mining, ventilation is considered one of the more effective means of controlling gases and dust. In order to study longwall ventilation in a controlled environment, U.S. National Institute for Occupational Safety and Health (NIOSH) researchers built a unique physical model called the longwall instrumented aerodynamic model (LIAM). The LIAM is a 1:30 scale physical model geometrically designed to simulate a single longwall panel. It has an 8.94 by 4.88 m (29 by 16 ft) footprint with a simulated face length of 220 m (720 ft) in full scale. LIAM is built with critical details of the face, gob and mining machinery, and scaled to preserve the physical and dynamic similitude. This paper discusses the gob-face interaction, airflow patterns within the gob, and airflow dynamics on the face for varying roof caving characteristics. Results are discussed to show the impact of caving behind the shields on longwall ventilation.

By W. A. Dixon Edwards

Industrial mineral production in Alberta, worth $468 million in 1997, comes from a dozen types of industrial minerals, mined by about 400 producers. Cement and lime from Paleozoic limestone formations exposed along the Rocky Mountains account for the greatest production value. Sand andgravel is the primary source ofmineral aggregate. Almost two-thirds of this aggregate is consumed in the Edmonton and Calgary regions. Sulphur produced at 48 sour gas processing plants and two oil sands plants was valued at $84.8 million in 1997 and accounted for 80% ofCanadian sulphur production. Four companies solution mine the Elk Point salt beds to produce chlor-alkali chemicals, industrial salt and sodium chlorate. Natural brine is also produced as a dust control product. Al $22 million, peat moss is a major industrial mineral product in Alberta. Other minerals with noteworthy production include shale, stone, silica and ammolite. The commodities with the greatest development potential are diamond, silica and oil sands tailings by-product minerals.

Jan 1, 2001

By Manuel Valerio Ortega

This Mexican amalgamation-process, invented in 1557, at Pachuca, by Bartolome de Medina, has been widely discussed in America and Europe, but thus far there is no universal agreement as to all the chemical reactions involved. Having been, after many trials, the first to succeed in effecting the amalgamation of silver-ores by the same mechanical means, but doing without one of the chemical substances which had been considered indispensable in the practice of 300 Sears, I am led to offer these notes as a contribution to the discovery of an exact theory concerning the patio process. My treatment for silver- and gold-ores being protected by letters-patent in this country, the United States, France, Peru, Bolivia and Chile, I may speak freely concerning its materials and manipulation. I. Patio-Amalgamation. The ore extracted from the mine is sorted by pepenadores, who break the large pieces with hammers, rejecting those which contain no ore, set aside the very rich to be smelted, and deliver the rest to be crushed and pulverized for direct amalgamation in the patio. The broken lumps, of about fist-size, are first ground in Chilean mills, and then reduced, in arrastras or tahonas, to fine slime. After the lama or slime has acquired a suitable consistency by the evaporation, through the sun's heat, of a part of the water which it contained, it is spread upon the patio or amalgamating-floor, where it is mixed with 5 or 6 per cent. of common salt. The next day a certain amount (depending upon

Jan 1, 1902

By Samuel M. Brock

In recent years society has become increasingly concerned with maintaining and improving the quality of environment. Thus, public interest and concern with pollution problems is now high. This is reflected in recent federal and state efforts to formulate new legislation to prevent pollution and strengthen existing pollution laws. In reviewing literature pertaining to pollution problems, it is possible to distinguish many common elements. The most outstanding of these is the failure of the market to guarantee that private firms responding to price signals generated in the marketplace will make decisions leading to optimal resource use. Cases of market failure in allocating natural resources according to the wants of society frequently are due to the presence of technical externalities, or side-use effects.59 These roughly and generally can be defined as interdependencies among production and consumption units, the impacts of which are exerted other than through the market. They are, in other words, extra-market relationships. The economic unit generating external effects does not take them into account in decision-making. Thus, the tendency is for the unit to produce either more than society desires or not enough. In such cases society often has intervened in the decision-making process. This intervention frequently has taken the form of legislation to regulate production and consumption activities. Thus, a body of institutions, which acts as a constraint in decision-making processes, has materialized. These institutions are often far more influential in their effect upon resource use than are the forces of supply and demand acting in the marketplace. The problem of environmental pollution is essentially the problem of handling residuals which are the byproduct of all production and consumption activities which take place in the economy.2 These residuals are emitted into the air and water and disposed of on the land. They are interrelated, in that efforts to control emissions into the air or water can result in the production of solid wastes, which then present disposal problems. It is convenient to separate residuals by the type of pollution they cause-air, water, and land while remembering that these problems are related and that solutions may require coordinated effort.1 Residuals may be produced in both production processes and consumption. Residuals produced in production by the mineral industry, or firms utilizing its products, range from emission of sulfur dioxide by steam generating plants to radioactive mill tailings produced in the course of mining uranium.. Residuals associated with consumption are generated mainly through transportation of members of the household, space heating, and in the disposal of solid wastes, including refuse and junk autos. Residuals associated with both production and consumption receive attention in ensuing sections of this chapter.

Jan 1, 1976

By Stephen John Brace

Increasingly, electronic blast initiation systems are being made available to the mining and construction community, both in South Africa and internationally. Indeed, in some parts of the world, perhaps half a dozen electronic products are being used, with a choice also of shock tube, electric and fuse and igniter cord systems. As these developments have taken place, improvements have been made in safety, reliability and accuracy, so much so that high performances in all these areas are now expected. However, disadvantages often seen by customers, other than : higher price, are decreased user-friendliness and loss of flexibility.

Jan 1, 1998

By Leonard Sargeant

The Pocahontas Coal Field consists of eight mineable seams of low-volatile coal in southern West Virginia and Virginia. The deeper seams, especially the Pocahontas No. 3 and No.4 Seams, under heavy cover and below drainage are notoriously gassy. Methane in the Pocahontas Field is generally thought of as being confined in the coal itself, rather than in mud slips or clay veins. Furthermore, it is characteristic of Pocahontas coal to retain its gas until the coal is broken and removed from the solid. Because of this inability for gas to escape from unmined coal, entries developed around large blocks are seldom of significant value in bleeding off methane before pillar extraction begins. This is evidenced by the fact that it is not uncommon to find gas liberated during the mining of chain pillars and barriers which have been developed for several years. The Pocahontas Fuel Company develops almost all solid coal by conventional methods with shuttle car haulage. To provide the maximum productive capacity without compromising ventilation and safety requirements, the Company has adopted standards for ventilating 5, 6 and 7-entry sections.

Jan 1, 1960

By Bruce E. Kester

The concurrent observation of the phenomena of alkali-aggregate reaction and development of efficient dust collection systems on rotary kilns made mandatory the process modifications to produce low alkali cements. Such low alkali cements as were available prior to these recent changes were either the rare result of low alkali raw materials, the loss of alkalies with dust loss from the kiln stack, or in some instances by the use of CaC12 in the kiln feed to increase volitalization of the alkalies and their subsequent loss or discard with the normal dust emission from the kiln. The relative slowly soluble nature of natural occurring alkali minerals in cement raw materials as compared to the very soluble nature of the alkali salts as present in cement kiln reaction products, either in clinker or in dust emission led to the development of the water leaching system. Two distinctly different problems of leaching are created by the two major systems of portland cement production, the wet and dry processes. The wet process is characterized by moderate dust loads and concentration of soluble forms of alkali in the dust. Further the return of the leached dust slurry does not materially change the characteristics of kiln feed on reintroduction and subsequently does not materially influence kiln operation. The dry process differs in high levels of dust emission and the presence in the collected dust of large amounts of unreacted kiln feed with its sparingly soluble alkali minerals. In the dry process reintroduction of leached dust slurry changes the dry process to what may be classed as a damp process. This change results in some decrease in kiln capacity and creates conditions of operation which are uncommon to either the wet or dry process.

Jan 1, 1963

By Lars O. Werme

Already the KBS Project proposed copper as a suitable material for encapsulation of spent nuclear fuel. The basis for this choice was the thermodynamic stability of copper in water and the fact that deep granitic groundwaters in Sweden are oxygen free. With a limited supply of oxidants, a copper canister would have the potential for a very long service life. The research and development work aiming at encapsulating nuclear fuel entered a new phase in 1993, when SKB launched its Encapsulation Plant Project. Within this project, SKB has: ? designed a facility for encapsulation of nuclear fuel, ? laid down the design premises for a canister for disposal of nuclear fuel, ? tested and developed fabrication methods for copper canisters, ? evaluated the long term chemical and mechanical behavior of the canister, ? made preliminary plans for a factory for the production of copper canister, ? constructed a canister laboratory for full scale testing of the key operations in an encapsulation plant. The conclusions of this project were that a canister consisting of an outer layer (50 mm) of copper over an insert of cast nodular iron would provide sufficient corrosion protection and would have sufficient mechanical strength. This canister can be produced by several methods of which forming from rolled plates, hot extrusion, and "pierce and draw" have been tested at full scale. The canister will be sealed by electron beam welding in the encapsulation plant, and the integrity of the weld will be verified by ultrasonic testing and' high-energy radiography. The final development work in this area will be performed in the canister laboratory.

Jan 1, 1999

By C. W. Schultz

The Mineral Resources Institute at The University of Alabama is engaged in a program whose objective is to develop a beneficiation system for Eastern oil shales. Prior experience (1,2) at The University had shown that the grind required for liberation of the oil rich kerogen was substantially below 20~m. Based on this fact and the rapidly emerging consensus that column flotation is the preferred method for ultrafine particle separation, efforts were focused on the column flotation of oil shale. This paper, which must be regarded as a progress report on a continuing MRI project, describes the observations made and the results achieved to date. The investigation is being conducted in two phases. The first phase has been completed and consisted of a factorially designed experiment conducted for the purpose of screening a set of primary flotation variables. The second phase, which is still in progress, is focused on optimization of the operating conditions and development of a flowsheet for specific shales.

Jan 1, 1989

By A. Yörükoglu

In this study, thorium mineral that found in the complex ore deposit bearing bastnasite, fluorite, and barite from Eskisehir - Sivrihisar district has been tried to extract by using HCl and H2SO4 leaching. Ore sample of approximately 3 tons taken from the ore deposit has been homogenized in order to obtain composite samples by means of ore preparation techniques for experiments. Results of chemical analyses of composite samples are as given; 40.8% CaF2, 35.35% BaSO4, 2.01 Ce, 1.5% La, 0.39% and 0.1% Th. HCl and H2SO4 leaching processes have been performed to gain Th in the ore. For determining the optimum particle size, the samples have been ground under controlled conditions and brought to the sizes of 0.065, 0.2, 1 and 3 mm. Leaching experiments have been carried out in both HCl and H2SO4 acids without roasting and roasting at the temperature of 900°C for 1, 3 and 6 h retention times for all particle sizes determined before. In the experiments, the highest Th recoveries reached are as follows; 78.74% Th when H2SO4 and 1 mm particle sized sample used, and 1 h roasting applied and 73.38% Th when HCl and 1 mm particle sized sample used, and 3 h roasting applied. Keywords: thorium, leaching, concentration, sivrihisar, roasting

Sep 1, 2012

By Valentine A. Chanturiya

The aim of this paper is basically to show progress in the study of nanosecond processes involved in the disintegration and breaking-up of mineral complexes with fine noble metals. We studied the influence of nanosecond High-Power Electromagnetic Pulses (HPEMP) on the physical and technological properties of refractory gold-containing ores and beneficiation products. Experimental data are presented to confirm the formation of breakdown channels and selective disintegration of mineral complexes as a result of pulse irradiation, which makes for efficient access of lixiviant solutions to precious metal grains and enhanced precious metal recovery into lixivia during leaching. Preliminary processing of gravity concentrate with a HPEMP resulted in significant increase of gold and silver extraction into lixivia during the cyanidation stage, with gold recovery increased by ~31% (from 51.2% in a blank test to 82.3% after irradiation). Gold recovery from stale gold-containing dressing tailings products increased after pulses-irradiation from 8-12% to 80-90%.

Jan 1, 2006

By J. T. M. Amphlett, C. A. Sharrad, M. D. Ogden, R. I. Foster

"A renewed interest in nuclear power around the world in order to reduce greenhouse gas emissions is going to increase demand for uranium as fuel. This will result in more uranium being mined, which will in turn increase associated environmental pressures, such as fresh water use. A move to lower quality waters containing impurities such as chloride would help alleviate these pressures. In this work, we determined the uptake characteristics of weakly basic anion exchange resin Ps-EDA towards uranium from saline solutions in a dynamic flow column. Breakthrough curves were produced, with suppression of uptake being observed for chloride concentrations above 5 g L-1. Calculated resin saturation capacities at zero and 5 g L-1 chloride are comparable with literature values for strong-base anion exchange resins, and exceed those published for weak-base resins up to 20 g L-1 chloride. Data has been fitted to multiple breakthrough models, with the modified dose-response model most effectively predicting uranium recovery. The results show that the ethylenediamine functionality could be suitable for use in future uranium processing flow sheets where a high-saline lixiviant is used. IntroductionIon exchange (IX) is a key technology in the uranium mining industry and is well established for the extraction of uranium from both acidic and alkaline leach liquors (Edwards and Oliver, 2000). It was first employed in 1952 at the West Rand mine in South Africa (Ford, 1993; Taylor, 2016). H2SO4 and Na2CO3 are the most commonly employed lixiviants used to solubilize uranium in acidic and alkaline leach conditions respectively. The chemistry of these systems causes uranium to form anionic sulphate or carbonate complexes, which can be taken advantage of by anion exchange resins.Another major technology for the extraction and purification of uranium from leach liquors is solvent extraction (SX). This technique involves the extraction of uranium from the aqueous phase into an immiscible organic layer. Although this is a commonly used method, there are major drawbacks to it, including the use of large volumes of flammable solvents, solvent loss, phase disengagement, third phase formation, and the production of problematic degradation products (Veliscek-Carolan, 2016). These problems can be circumvented through the use of IX resins."

Dec 1, 2018