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By J. Nakayama

For drilling large diameter holes for deep foundations, the common and distressing difficulty of long standing has been in coping with ground containing rocky formations and boulders. Where geological formation contains weathered rock or boulders, or deep rock socket is specified, drilling equipment occasionally is found to be unable to drill through and therefore will need supplementary equipment and procedures. Incentive of the MACH Drill Development has been to realize a capable drilling system for rocks of weathered to fresh rock without losing its applicability to usual overburden. Through seven decades' experience of manufacturing and operation of boring machines, the best features of all sorts of drillhead are known such as the drag bit, wing bit, auger bit, diamond bit, rock roller bit, down-the-hole hammer bit, etc.

Jan 1, 1988

By Larry A. Haas

The U.S. Bureau of Mines is investigating ways of enhancing the high-temperature softening-melting (HTSM) properties of domestic taconite pellets. These properties, which are important for determining the performance of pellets in blast furnaces, include pellet bed contraction, pressure drop, S-value (area under the pressure-temperature curve), and softening and metal-slag drainout temperatures. Experiments showed that HTSM properties were related to the physiochemical properties (fired strengths and reducibilities) of pellets containing different levels of limestone and dolomite flux. Flux additions resulted in slightly lower green and fired pellet strengths, but improved metallurgical properties, such as reducibility. The influence of reduction conditions on HTSM properties was evaluated by varying the pellet metallization starting temperature and the carbon monoxide content of the CO-N2 gas mixture. HTSM property change was more sensitive to flux addition levels when metallization was initiated at 1,100° C with 20 pct CO in the gas stream. The S-value and the metal-slag drainout temperature were found to be the best criteria for characterizing HTSM properties. The optimum flux addition level was about 8 pct (4 pct dolomite, 4 pct limestone) or a basicity of about 1. At higher flux levels, a higher metal-slag drainout temperature was obtained.

Jan 1, 2010

This paper sets out to examine the possible relationships between three factors, they are, the rate of growth of world production of minerals, the growth of Australian production and the growth of scientific and engineering knowledge.The first two are quantified, in terms of tonnes and value. The third, an abstract concept "knowledge", requires to be quantified, in terms of manpower.A mathematical model, which has general application, was derived to demonstrate certain axiomatic premises and to define, more precisely, basic concepts related to the philosophy of knowledge.Finally a summary is made of education-cum-industry issues.

Jan 1, 1981

By A. D. Hahn

The Federal Bureau of Mines examined ilmenite-bearing sands in southern Texas as part of a program to discover sources of supply for the domestic titanium industry. Deposits were examined from May 1956 through January 1959 in the outcrops of sandstone beds in the Jackson group of Eocene formations in Lee, Burleson, Fayette, and Starr Counties on the Gulf Coastal Plain; in alluvial valley fill in Brewster County in southwest Texas; in the sand beaches of Matagorda Peninsula and the Galveston, Padre, and Brazos Islands--part of the offshore chain of barrier islands along the Texas coast; and in unconsolidated sediments in Willacy County on the Rio Grande delta in the southeast Texas.

Jan 1, 1961

By F Hancock

A rainfall simulator was developed to assist with hydrogeomorphic research into the stability of engineered landforms associated with rehabilitated uranium mines in the Top End of Australia. It can be used in rough terrain with slope gradients up to 30o. The rainfall simulator is modular, utilises upward jetting nozzles, has a multiple head arrangement and is capable of delivering rainfall intensities between 60 and 300 mmh-1 over areas up to 1000 m2 and could be easily modified for larger areas. Rainfall uniformity is commonly in excess of 80 per cent and the kinetic energy approaches that of natural rainfall (The modular design utilises an equilateral triangular array of rainfall stands, constructed from galvanised steel water pipes and flexible plastic hoses. Total construction costs are low. The water supply reservoir is mobile and easily constructed. An example of its use at Ranger Uranium Mine, investigating the effect of cover on rainsplash and rainwash dominated processes shows that vegetation cover is likely to reduce the erosion rate by these processes by at least four times below that experienced on bare areas.

Jan 1, 1997

Economic Sustainable Power for Mineral Processing

Sep 13, 2010

By A. Roca, G. Ríos, I. Ruíz, M. Cruells

Flash Smelting Furnace (FSF) hot dust-laden is cooled in a waste heat boiler (WHB) and then dedusted in electrostatic precipitators (ESP’s) before being treated, together with the Peirce Smith Converters off-gases, in the sulfuric acid plants for SO2 removal. FSF dust is sulfated by SO2 and O2 in the WHB. Typically, 70% of the dust from the FSF drops in the WHB while the remainder is caught in the ESPs. The collected dust is recycled to the FSF for Cu recovery. Some smelters have developed hydrometallurgical treatments to recover Cu from the dust; impurities, such as As and Bi, are bled as leach plant residues. This paper presents a study (laboratory scale), of leaching the FSF dust, generated in Atlantic Copper Smelter using the weak acid bleed from the gas scrubbing/cooling section (GSCS) of sulfuric acid plants. Leaching was performed with 0.5 mol L-1 sulfuric acid concentration, 60ºC, and a solid/liquid ratio 1/3. After leaching, H2O2 was used for arsenic and iron oxidation. pH was adjusted for precipitation of arsenic and iron as scorodite or as scorodite and arsenical jarosite. The precipitation was carried out at 95ºC during 3-6 h. Liquids after precipitation are suitable for subsequent treatments of electrolysis. INTRODUCTION The copper smelter dusts are usually recirculated totally or partially to the flash furnace. This practice increases the amount of impurities feeding the furnace. Some authors have developed processes for treatment of these materials for copper and zinc recovery and for arsenic, antimony and bismuth inertization. The processes for the treatment of copper smelter dusts can be pyrometallurgical (Yu, 1987; Carter, Vance, Aldridge, Zaw, & Khoe, 1994; Fu, Jiang &Wang, 2000), hydrometallurgical, or mixed processes (Yin et al, 1992; Mulale, Mwema, & Mashala, 1999; Gorai, Jana, & Khan, 2002). Hydrometallurgical processes have been extensively studied and, in some cases, applied to an industrial scale. The most important chemical reagent proposed for leaching the dusts has been sulfuric acid (Roman-Moguel, Plascencia, Pérez, & Garcia, 1995; Gabb, & Evans, 1997; Larouche, 2001; Morales, Cruells, Roca, & Bergó, 2010; Cáceres, Cruells, Morales, & Roca, 2012; Ecometales, 2013; Yang, Fu, Liu, Chen, & Zhang, 2017). Processes developed in alkaline media, and in some cases with the presence of sulfide, have also been carried out (Gabler, & Jones, 1988; Morales, Hevia, & Cifuentes, 2009; Alguacil, Garcia-Diaz, Lopez, Rodriguez, & Alonso, 2013), as well as by using a bioleaching process (Massinaie, Oliazadeh, & Seyed Bagheri, 2006; Bakhtiari, Atashi, Zivdar, Seyedbagheri, & Fazaelipoor, 2011).

Jan 1, 2019

By William J. Rothschild

Ground water at construction sites can be controlled by properly placed wellpoint dewatering systems. Care must be taken in planning cofferdams to have adequate space for and access to pumps, headers and the points. A most important part of dewatering is protection of adjacent structures from movement. A checklist gives items to consider in bidding.

Jan 1, 1984

By Thomas M. Barczak

The resultant load vector is the representation of the forces applied to a longwall roof support element by caving strata into a single, quantifiable measure of support resistance. The relatively complex kinematics of the shield support prohibit a determination of support resistance simply by summation of leg forces. A method is being investigated by the Bureau of Nines to determine the resultant load vector by instrumenting supports with pressure transducers and strain gages to measure leg, canopy capsule, and lemnisoate link forces. This concept has been laboratory tested in the Bureau's Nine Roof Simulator. Functional relationships among variables have been assessed, and confidence intervals have been established for prediction of the resultant load vector parameters.

Jan 1, 1984

By T. W. Camm

"As engineers, we are trained to use logical, rational problem solving to insure our mines operate at maximum efficiency. We tend to use the same technical approach to design safety into all mining systems. This works well for machines, but not so much for the human component. Recent insights in the field of behavioral economics provide useful ideas for addressing the fact that we are driven by emotions more often than by rational thought. Understanding the nonrational aspect of human behavior is an important piece of any safety system design. INTRODUCTION The most common economic model is based on humans making rational decisions; that given the proper information, we will make a logical, rational decision based on what is best for ourselves (Ariely, 2009, p. xviii). In many cases this is an accurate description of how we make decisions. As an engineer, I was trained to apply the precision of mathematics and logic to solve problems. As an engineering professor, I now teach this approach to bright young minds preparing them for a life of professional effectiveness as practicing engineers. That said, we are not only rational. Daniel Kahneman, winner of the Nobel Prize in Economics, describes a model for how we think (Kahneman, 2011). System 1 is the part of our mind that is fast, intuitive, and emotional; while our logical, slower, and deliberative mind is System 2. According to Kahneman’s model, System 1 runs automatically, most of what you think and do originates in System 1. System 2 takes over when things get difficult, including the application of math and logic, and the resolution (or avoidance) of conflict. As engineers, we would typically assume that we operate in System 2 mode most of the time. This is where the model becomes useful, for Kahneman points out two important aspects of the dynamic between the two systems in our mind. First, System 1 has biases, systematic errors that lead to answering questions with an easier answer (rather than a right answer) before System 2 is engaged. Second, we can be blind to the obvious, and also be blind to our blindness. Complicating things further, System 1 cannot be turned off (Kahneman, pp. 24-25)."

Jan 1, 2015

By Tyler R. J

Methylene blue dye adsorbs on chalcopyrite concentrates slurried in aqueous solution. Saturation adsorption can be achieved within about 24 hours for dye equilibrium concentrations greater than about 10-5 M. The dsorption coverage is obtained from a measurement of the' colour change of the solution. Comparison with BET measurement of the concentrate surface area shows that 2.4 ± 0.1 µmol of methylene blue are adsorbed per square metre of surface accessible to the dye cation. The procedure described can be used as a single-point measurement and values for the surface area can be otained to within about 10 per cent with inexpensive instrumentation.

Jan 1, 1979

By David Dreisinger

The cyanidation of copper containing gold ores results in the co-dissolution of copper along with gold. Copper dissolution results in elevated cyanide consumption that may make the treatment of the gold ore uneconomic. Copper-cyanide species in gold mill effluents may increase the environmental toxicity of the gold mill solutions. The objective of this study was to examine the use of solvent extraction to recover the copper cyanide species from gold mill effluents. Solvent extraction with Cognis (formerly Henkel) reagents LIX 79 and LIX 7950 was studied. Excellent extraction of copper and cyanide was achieved using pH control in extraction. Copper and cyanide may be stripped from the reagents using basic eluants. Various routes for copper and cyanide recovery from the strip solution were studied. Excellent results were obtained using electrowinning in both divided (Nation membrane) and undivided cells. Cyanide recovery was obtained by AVR treatment of a bleed stream from electrowinning. Full results of solvent extraction, copper and cyanide recovery are reported.

Jan 1, 1998

By Sara Jane Boles

In recent years the interest in rare-earth compounds as refractory materials has exceeded the available literature on the subject. While some basic properties, such as density and melting point, of the more readily available rare-earth compounds have been reported in the literature, relatively few papers can be found that deal comprehensively and primarily with high-temperature refractory properties and applications of rare-earth oxides, carbides, sulfides, and nitrides. Therefore, this bibliography has been pre-pared for the use of the ceramic industry as a guide for locating and utilizing the scattered and frequently fragmentary information available. The term "rare earths", as applied in the literature search for this bibliography, is understood to include the following elements: cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, samarium, terbium, thorium, thulium, uranium, and ytterbium. (On the periodic chart, these elements appear as numbers 57 through 60, 62 through 71, 90, and 92.) It is emphasized that many of the abstracts included are from papers in which the rare-earth compound or compounds are treated along with several other ceramic materials, are mentioned only secondarily, with primary interest placed on a more commonly used refractory material, or are used as part of a mixture of materials formed experimentally and reported on in the paper. As the better known rare-earth materials, such as the oxides of uranium, thorium, and cerium, appear more frequently in the literature, they also appear more frequently in this collection. Articles abstracted include only information on the basic properties that are of interest to the refractories investigator. References to crystal lattices and related topics are generally excluded from this publication. The temperature 1,500° C. has been set arbitrarily as the lower limit for reported data on thermal properties. However, because of the scarcity of information, some reports are included in which data are limited to those obtained at lower temperatures. Many of the articles abstracted include lists of references that will be of additional assistance in pursuing specific lines of investigation.

Jan 1, 1962

By John Organiscak

A majority of continuous mining machines employ a water spray system and a machine mounted flooded-bed scrubber to suppress and capture dust during coal mining. These machine mounted dust control systems must be designed to function within the localized face ventilation system at the mining section to control both dust and methane. Spray systems can impede or improve the scrubber effectiveness in controlling dust or methane at the mining face. Laboratory experiments were conducted to examine the effect of spray type, spray pressure, machine body blocking sprays, and scrubber airflow on dust and gas levels while using a 12.2 m (40 ft) exhaust ventilation curtain setback from the face. These experiments were conducted with the mining machine positioned at the end of a simulated 6.1 m (20 ft) sump and slab cut. Results indicate that the hollow cone nozzles with blocking sprays best complemented the flooded-bed scrubber performance in an exhaust ventilation system. This external spray system notably reduced dust and gas levels on the off-curtain side of the mining machine for both the sump and slab cut as compared to the flat spray nozzles. Higher scrubber airflows reduced dust and gas levels on the curtain side and in the return of the continuous mining machine. The remote operator position, located on the off curtain side and parallel to the inlet end of the exhaust curtain, sustained the most stable and lowest dust levels around the mining machine.

Jan 1, 2010

By K Palmer, G J. Artmont

Alluvial gold is an ideal exploration tracer to bedrock source and indicator of bedrock mineralisation style because: (i) gold occurs in a wide range of deposit types, (ii) primary composition is sensitive to style of mineralisation, and (iii) it is a heavy resistate mineral that is readily preserved and easily sampled. In regional exploration of the Central Ranges of Irian Jaya, alluvial gold mineralogy has been applied to maximise the information return from panned concentrate sampling and to focus exploration effort. Primary gold is a solid solution of Au+Ag¦Cu¦Hg, ¦ trace Pd, Te, and Sb. In general Ag¦Hg increase and Cu decreases with inferred decreasing temperature of formation, and gold from particular mineralisation styles has signature compositions that can be used as indicators of bedrock mineralisation type. Furthermore, the abundance of alluvial gold is an indicator of the economic potential of a catchment. The convergent continental-oceanic plate geology of the Central Ranges is conducive to a wide range of mineralisation styles. Mineralogy of gold in ophiolite, skarn, porphyry, mesothermal vein and possible VHMS environments is characterised from alluvial and bedrock samples, and the use of gold mineralogy in prospecting at regional scale through prospect definition to drilling is demonstrated.

Jan 1, 1995

By D. W. Alexander

Researchers from the Office of Mine Safety and Health Research (OMSHR) of the National Institute for Occupational Safety and Health (NIOSH) completed field trials during coal mine rescue contests using simulated gas detectors in place of placards. The gas monitor simulator (GMS) devices replaced static, paper placards to deliver gas concentration data. Eleven teams were observed during the field contest, which was approved by the Mine Safety and Health Administration (MSHA). GMS devices were given to three team members, the captain, and both gasmen. Observation of teams revealed that team members changed behavior by acknowledging and sharing information more often while using the GMS. As a result of this research, it has been demonstrated that under the existing contest format, the newly developed GMS device may be used with no adverse impact on team contest performance. Furthermore, when GMS technology advantages are used, contest realism is improved. In the future, competency assessment may be incorporated.

Jan 1, 2011

By W. J. Kingwell

Where the equipment, technique and materials are available for the construction of large diameter rock socketted piles, this is frequently the most economical and environmentally acceptable method of supporting very large concentrated foundation loads in geoglogically appropriate areas. This paper outlines the current approaches in Australia to design and installation of large diameter rock socketted piles. The equipment and procedures described generally reflect those developed or used by Vibro-Pile (Aust.), a company which, while installing the usual range of driven and bored piles, specializes in the design and construction of large diameter rock socketted piles and possesses special expertise in drilling in high strength rock. A high capacity crane attached drill for large diameter drilling in rock is briefly described. Discussed in detail are the construction techniques employed and structural and geomechanical design methods adopted.

Jan 1, 1989

By F. Burat

Large reserves of feldspar ore exist in the Aegean region of Turkey. The main colored impurities in these ores are iron- and titanium-bearing minerals such as anatase, rutile, sphene and ilmenite. In this study, a potassium feldspar ore containing mainly quartz and coloring impurities was subjected to beneficiation tests involving magnetic separation and flotation, which were applied either separately or in combination. Bench-scale flotation experiments using cationic collectors G-TAP and Flotigam V-4343 and using HF and H2SO4 as modifiers were employed to separate feldspar from quartz and to remove part of the titanium impurities. The best results were achieved with a combination of high-intensity wet magnetic separation and flotation. A feldspar concentrate containing 16.28% Al2O3, 10.75% K2O, 2.84% Na2O, 69.97% SiO2 and 0.16% Fe2O3 was produced. A quartz concentrate containing 2.30% Al2O3, 0.48% K2O, 0.42% Na2O, 0.07% Fe2O3 and 96.20% SiO2 was also obtained

Jan 1, 2007

By P. A. Rey

Water recycle is an important part of the coal preparation process. This study was directed toward: (1) a survey of current practice and an evaluation of both the solid and liquid components of blackwater, (2) an experimental study of blackwater flocculation, and (3) a fundamental analysis of the flocculation process. The solids contained in the blackwater discharge to the fine refuse thickener of a coal preparation plant were found to contain, on average, 56% coal and 44% mineral matter. The mineral matter was largely illitic clay, while the water phase contained relatively large amounts of S04 and Ca++. Detailed studies were made of both natural and synthetic flocculants and the influence of polymer type and pH on the settling rate, turbidity of the supernatent liquid and sludge volume of the settled solids. More tundamental studies were made that clearly indicate the need for controlled mixing of polymer into the suspension to be flocculated, and the need to evaluate, more closely, the structure of the flocs formed during the process. Research recommendations are given.

Jan 1, 1983

By N. M. Safaya

Moderate to acute deficiency of plant available phosphorus is very common in western coal mine spoils and topsoils. Although some of the spoils are known to contain seemingly adequate amounts of total phosphorus, the plant available phosphorus is so low that it constitutes a serious plant growth limiting factor in the mined lands. For the revegetation of these spoils, the use of species, varieties and ecotypes exhibiting greater efficiency for P uptake and utilization, or conversely, lesser susceptibility to P deficiency would be highly desirable. To identify such plants, quick and adequate methods of screening germplasm should he available. In the present growth chamber study several plant species were screened using continuous flow culture and spoil culture systems to provide information on their relative susceptibility. In flow cultures, P was maintained at 0.25, 2.5, and 25 moles; while in spoil cultures it was applied at 0, 25, and 75µg/g to a P-deficient spoil. Phosphorus deficiency symptoms appeared in alfalfa cultivars, birdsfoot trefoil, emerald crownvetch and yellow sweetclover within 7-10 days upon transfer of their seedlings to U.25 or 2.5 µM P solutions. Burning bush and Russian thistle, found abundantly as pioneering species on mine spoils, showed no deficiency symptoms; their shoot dry matter yield in the 0.25µM P treatment was 24% and 36%, respectively of their maximum yield obtained with 25 µM P. However, the percent increase in the dry matter yield of legumes with 0.25 µM P ranged from 7-13% over their maximum yield. With the increase in solution P concentration, the root dry weight ratio in the legumes increased from an average of 0.22 to 0.43, while in the weeds from 0.14 to 0.30. The low susceptibility of Russian thistle to P deficiency was also demonstrated in the spoil culture experiment. Legumes showed greater response to P-fertilization on the spoil than did the two weeds. With increasing concentrations of P in the solution, the root weight ratio of all the species decreased. At 25 µM P, weeds invested only 14% of their total dry matter yield in the root fraction, where as legumes and grasses invested as much as 24% and 33% respectively. Weedy species averaged higher P concentrations than the legumes and grasses. The mean P concentrations of alfalfa cultivars were the lowest among legumes. In general, P concentrations increased with the increase in P supply. In the flow culture system, P supply increased the Ca levels of legumes. The mean Mn concentrations were highest in the weedy species. The increases in P supply decreased Zn levels in all of the species. File effects of P fertilization on the tissue concentrations of Mn and Zn in spoil culture were similar to that of flow culture system. From this preliminary study, it may be concluded that the continuous flow culture system is efficient in rapid screening of a large number of species under controlled conditions for their efficiency in adapting to mineral stresses.

Jan 1, 1982