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By Susana Bolhão Muiños, José Hipólito Monteiro, Martin Frank, James R. Hein, Henrique Garcia Pereira, Fátima Abrantes, Tracey Conrad, Luís Gaspar

In spite of all the work that has already been done on ferromanganese deposits, studies on the Atlantic Ocean occurrences are still in their infancy and there is a clear need for investigations concerning the origin, distribution, and resource potential assessment of these deposits. Nevertheless, studies already carried out on northeast Atlantic seamounts indicate the general presence of ferromanganese deposits of hydrogenetic origin, i.e. deposits formed by direct precipitation of colloidal, hydrated metal oxides that are scavenged from the water column on hard-rock substrates. The hydrogenetic precipitation promotes the enrichment of ferromanganese crusts in many trace metals, most of which are of economic interest, such as Co, Ni, Te, rare earth elements, and platinum-group elements and thus ferromanganese crusts are considered an important metal resource.

Sep 1, 2014

By Young-Dong Cho, Yonghun Jong, Dong-See Shim, Seokwon Jeon, Chung-In Lee

The most important operation in the tunnel blasting procedure is to create an opening in the face in order to develop more free surface in the rock mass. This operation is highly dependent on the cut holes. In general, the burn-cut or V-cut is commonly adopted to blast the cut section. But, these traditional methods often raise problems. There are instances (a) that the actual advance is considerably less than the designed advance depending on the rock mass, (b) that they cannot sometimes enlarge the free surface efficiently and (c) that the blast vibration resulted from the cut blast exceeds the allowable vibration level. In order to resolve the problems, many different kinds of the cut blast can be considered.

Jan 1, 2005

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network. and 2)development at a set pit digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the models and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated fur their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

By Louis C. Britcha

"The Phelps lease in Jasper County, Missouri, was first examined by the Bureau of Mines3/ in December 1943, at the request of Thomas Phelps of Joplin, the lessee. Owing to urgent war requirements for zinc and lead and evidence of favorable geological conditions and past productivity of adjoining properties, it,considered justifiable to explore for extensions of known ore deposits and possible undiscovered ones. In August 1944, funds were allotted for this work, which was started January 5, 1945, under the direction of the author.The provision of facilities and storage space on the property by the lessee during drilling operations is gratefully acknowledged.The Phelps lease is on land belonging to the Rex Mining & Smelting Co. It lies immediately southeast of the city limits of Joplin, Mo. It may be reached by going cast from Joplin on paved 20th street to half a mile beyond Range Line road. Twentieth street is the northern boundary line of the property, which consists of approximately 145 acres and includes the W 1/2, NE1/4, and all of the E ½. NW1/4 except 15 acres along the west side of that quarter section, of sec. 18, T. 27 N., R. 32 W., as shown on figure 1.The property is part of a 1,000-acre tract owned by the Rex Mining & Smelting Co., Paul D. Porter, president, Joplin, Mo. The lease was acquired by Thomas Phelps of Joplin, in 1937. At present the lease is controlled by a recently formed association known as the Eureka Products Co., Charles W. Madison, manager, Kansas City, Mo.Dependable skilled mine labor is scarce in the district at present, but there seems to be enough transient mine labor for small operations. The prevailing wages of the district run from 55 cents to 95 cents per hour for various types of mine labor.Living accommodations and markets to supply all domestic requirements are available in Joplin.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the and that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director."

Jul 1, 1946

By C. J. Hall

I would like to congratulate Professor Gershon on an idea that is obviously valuable and is certainly new to me. It has, however, to be further developed, in that one can get fallacious results by limiting oneself to positional weights. In the example problem, the positional weight of one block was 8.6 (the 8.0 value in the paper was incorrect) for 36 units in the cone, for a mean block value of 0.239. The positional weight of the second block was 4.4 for 15 units, for a mean block value of 0.293. Surely one would expect the second block to be rated higher. Additionally, the time value of money adjustment cannot be determined by depth, because the time that a block is mined is determined by the mining sequence, not depth. Figure 1 shows a slightly altered version of Professor Gershon's pit. The overall value of the pit is the same, as are the total values under each of his blocks. The values in the right-hand cone have been reversed top to bottom, and the values in the rest of the pit adjusted to keep the central cone total unchanged. All values have been multiplied by 10. Figure 2 shows the sequence of mining, at three blocks per year, for Professor Gershon's pit, and Fig. 3, the sequence for a pit under the other block. Table 1 shows the value and discounted value (15%) of Professor Gershon's pit, and Table 2 shows similar values for the second pit. It is apparent that the second pit schedule is more valuable than the first.

Jan 1, 1988

By R. C. Hall

We are pleased to confirm some of the mechanical data presented by Dr. Detert on the 18 pct Ni marag-ing steel.15 Bar 3 in. in diam and containing 0.02 wt pct C, 18.5 Ni, 8.9 Co, 5.1 MO, 0.55 Ti, 0.05 Al, and balance iron has been examined in our laboratory. Cylinders 0.5 in. high and 0.4 to 0.5 in. in diam were cold-compressed from 3 to 40 pct reduction in height. Table VI shows some typical data; deformation in-

Jan 1, 1968

By Reno Pressacco

Abstract- Agrium Inc. is a world leader in the production, distribution, and marketing of agricultural products and services in both North America and Argentina. The new phosphate mine and mill complex located southwest of Kapuskasing, Ontario, was constructed to replace an offshore supply of phosphate rock, and produces a high-grade phosphate concentrate. The Cargill Township Carbonatite Complex is one of a series of carbonatite complexes in the region that are hosted by the 1.9 Ga aged Kapuskasing Structural Zone. The carbonatites in the mine area have intruded Archean gneissic granodiorite rocks of the Wawa Subprovince, and metasedimentary rocks of the Quetico Subprovince. The Cargill Carbonatite Complex displays a typical concentric zonation pattern from an outer ring of alkalic pyroxenites, through an inner ring of sövite-carbonatite, to a central core of rauhaugite-carbonatite. The initial carbonatite intrusion and subsequent residual orebody have been modified by faulting such that the northwestern third of the complex has been displaced approximately 2.5 km northeast. The phosphate ores are composed principally of residual apatite sands that were formed by the weathering and dissolution of the soluble minerals of the carbonatite protolith. These ores are subdivided by their iron content into high grade (A ores) and lower grade (B1 and B2) ores. They are separated from the primary unweathered carbonatite by a layer of saprolite, whose thickness varies depending upon the composition of the underlying carbonatite. Cretaceous waste materials consisting of well-sorted silica/kaolinite sand and peat deposits are typically found to stratigraphically overlie the ores. A minor amount of the ore feed comes from cemented phosphate ores. All rock types are covered by Pleistocene glacial tills and clays.

Jan 1, 2001

By G. B. Harris, C. W. White

Cyanide has been used for the recovery of gold since the mid 1800s, but several jurisdictions have already banned its use, and environmental pressures are increasing to finding an alternative. Gold also forms chloride complexes similar to those of cyanide, but the use of chloride has never achieved widespread acceptance. This paper describes a chloride-based flowsheet, wherein the key unit process is the recovery and recycle of chloride ion. It is shown that the chloride-based flowsheet is competitive economically with the conventional cyanide-based flowsheets, and that it has a number of other advantages, particularly environmentally.

Jan 1, 2011

By Anthony Spencer

The mining industry internationally seems on the verge of a major underground support revolution as suppliers, mines, consultants and researchers develop, test and use thin support (structural) membranes (or superskins) Membrane support in the form of shotcrete has been used since the 1950s in underground mines. Shotcrete (sprayed concrete) is generally applied at a thickness depend on the need. There is, however, considerable confusion concerning such support technology, and this paper attempts to clarify certain aspects, and dispel certain misconceptions and myths about the support membrane needs and advantages influence the thin membrane uses underground.

Sep 13, 2001

The emergence of China as a global economic power has not been without its birth pangs and the current coal market is testimony to this. Traditionally the coal market has been controlled by mature economies that functioned along balanced lines of supply and demand. The emergence of China and India as major forces in the international market has shifted this balance of power from mature economies to the developing economies of China and India. Of late Chinese Central Government policy has caused wide swings in the supply of Chinese coking coal and thermal coal to the international Asian markets. This has resulted in huge increases in demand for coal from producers in Australia, Canada, Indonesia, USA and Russia. Additionally since the late 1990s the liberalised Chinese economy has been growing by between nine to 12 per cent per annum. The corresponding rise in the standard of living of their 1.4 billion people has resulted in a strong demand for raw materials, initially met by domestic production and more recently met by the importation of raw materials including iron ore, oil, coking coal and thermal coal. Commensurate with this growth in China has been the emergence of India (pop one billion) as another major developing economy in the region. Whilst the Indian standard of living is lower than that of the Chinese, this subcontinent still has some 300 million people with middle class consumption demands. India is a major importer of oil, coking coal and thermal coal. It exports iron ore to China with growth parallel to China (seven to nine per cent per annum). These combined new demands from India and China have put unprecedented pressure on the global supply of coking and thermal coals. These pressures are reflected in the current world spot prices for coking and thermal coals which are at historically high levels. Whilst current demand from China and India is high it is anticipated that new projects will partially satisfy this increasing demand. Expectations are that overall thermal and coking coal prices will rise steadily. This paper seeks to identify the potential effects of Chinese and Indian economic growth on the international markets for coal.

Jan 1, 2004

By A Self, B Robertson

During 2015 and 2016, the authors conducted a number of surveys, workshops and reviews of ventilation and gas management practices in Australian underground coalmines. The study was funded by ACARP with a brief to identify gaps in ventilation and gas management practices for current and future needs, and to prepare a road map for change that would assist in delivering improvements.The study found that despite many examples of leading practice, gas and ventilation management is not afforded the attention and priority that is warranted and that this must be remedied if future operational performance targets are to be achieved and the safety of the industry protected. This paper summarises the findings of the study and presents the recommendations proposed.CITATION:Robertson, B and Self, A, 2017. A review of ventilation and gas management in underground mines, in Proceedings Australian Mine Vent Conference 2017, pp 277–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By E Christodoulou, L Zoumpoulakis

The kinetics of the thermal decomposition of MgCO3 was investigated using isothermal experiments performed in a thermogravimetric analyzer under a nitrogen atmosphere at 380¦, 400¦, 450¦ and 480¦C. The weight loss data as a function of time were modified to give the fraction that reacted (ß) and the rate of reaction (dß/dt) vs. time (t). Kinetic analysis of the experimental results, using three different methods, showed that diffusion predominates the MgCO3 decomposition over the investigated temperature range, with the data being best fitted by JanderÆs equation ([1−(1−ß)1/3]2=kt). The activation energy was estimated by Arrhenius plots using both the initial reaction rates and rate constants from fitting the above equation. The values estimated were 27.1 and 171.4 kJ/mol respectively.

Jan 1, 2001

By S. Lubbe

South Africa and Australia are the biggest suppliers of zircon sand to the international zirconium industry. However neither South Africa nor Australia is well known for zircon beneficiation. Geratech Zirconium Beneficiation Ltd (GZB) continued with additional research on sodium hydroxide (NaOH) cracking of zircon sand during 2002-2003. In 2003 GZB started extracting zirconium from zircon sand by means of NaOH cracking on a commercial scale. Experience has shown that temperature profile and atmospheric control inside the furnace is crucial for the beneficiation of zircon sand. Silica carryover to zirconium chemicals could result if a high temperature is used. Once the sodium silicate is extracted from the sodium zirconate and dissolved in hydrochloric acid, two distinct routes can be followed to precipitate various zirconium chemicals. The most common route is to precipitate zirconium oxychloride crystals (ZOC), with subsequent purification from all contaminants (crystal route). Less known is the process (liquid route) that involves the direct precipitation of zirconium basic sulphate (ZBS). This route will yield a less pure product, with contaminants such as silica and titanium. An important factor in this route is the prevention of silica gel formation, which could hamper final product filtration. For applications like paint drying (zirconium octoate) or antiperspirants (zirconium hydroxychloride) low levels of contaminants have no effect on the final product. The advantage of the liquid route is fewer production stages compared to the crystal route. The disadvantage of the liquid route is that the market for the products will be significantly smaller. The optimum solution could be a plant design that could cater for both routes. Another example of an application of zirconium chemicals is the use of ammonium zirconium carbonate (AZC) in the paper industry. Zirconium basic carbonate (ZBC) is dissolved in ammonium carbonate to produce AZC solution. AZC is used mainly in European countries in the paper industry. For example, carton boxes were initially produced with formaldehyde as the binder, however, it has now been replaced with AZC since formaldehyde is considered toxic. AZC reacts with the cellulose fibres in the paper to act as the binder. The resulting product is not toxic, and printing ink dries very quickly due to the porous paper structure. Other applications of zirconium chemicals involve the use of acid zirconium sulphate tetrahydrate (AZST), zirconium orthosulphate (ZOS), potassium zirconium carbonate (KZC), and zirconium hydrous oxide (ZHO). Fluoride-based zirconium chemicals like zirconium tetra-fluoride (ZrF4) and hexafluoro-zirconic acid (H2ZrF6) are used in the aluminium industry. Zirconium oxide (Zr02) can be produced from any of the abovementioned precipitated chemicals via a high-temperature decomposition process. The physical properties of such oxides can differ tremendously, depending on the final application. The fired density of sanitaryware is typically 5.8 g/cm3, compared to milling media at >6.1 g/cm3. The required fired density is achieved by controlling the precipitation and decomposition conditions for these two oxides. The same applies to stabilized and mixed oxides, for example where zirconium oxide acts as an oxygen carrier in fuel cells.

Jan 1, 2012

By F. Hassani, R. Mikaeil, B. Ferdowsi

Two analytical solutions for estimating the ovaling deformation and forces in circular tunnels are widely used in engineering practice, due to soil-structure interaction under seismic loading. This paper discusses the discrepancy between the two analytical and finite difference methods. A comparison of the two analytical methods shows that the calculated forces and displacements are identical for the condition of full-slip between the tunnel lining and ground. However, the calculated lining thrusts differ by an order of magnitude when considering no-slip between the tunnel lining and the ground. The analytical solutions are compared to numerical analyses of the no-slip condition using the finite difference method to validate which of the two methods provide the correct method. To achieve the goal, numerical modelling, field data of the Kuhin railway tunnel and Manjil earthquake characteristics are used. Numerical analysis results agree with one of the analytical solutions that provides a higher estimate of the thrust on the tunnel lining, thus highlighting the limitation of the other analytical solution.

Jan 1, 2008

By Steve Stuart

Deep-sea mineral SMS deposits present some of the world’s most challenging conditions for drilling equipment. As robotic seabed drilling services mature so too the ways that clients engage with service providers to maximise their data requirements. This presentation reviews key considerations for planning and executing a successful seabeddrilling program in variable mineralised deposits. Some of the means of collaboration between robotic seabed drilling contractors and those hiring their services are explored; where improved efficiencies and recoveries over the period of a drilling programme could be achieved. Potentially new technology or methodology can be looked at to further improve these approaches.

Sep 1, 2014

By Glen Frank, David R. Chapman

Determining the number of boulders and cobbles that will be encountered in the tunnel envelope is one of the most difficult problems confronting the geotechnical engineer in the design of tunnels in glacial terrain. This issue is very important to the contractor, both in determining what methods will be used to construct the facilities and the advance rate that can be achieved for the chosen construction methods. The cost of constructing tunnels by pressurized face tunneling techniques is very sensitive to accurate characterization of the very coarse fraction (large cobble and boulder sized clasts), and no standard method is current available for characterizing boulders and cobbles. Careful use of large diameter borings and the sampling and analytical techniques outlined in this paper can provide a means to answer this difficult question. By performing large diameter borings and carefully recording and sampling the cobbles and boulders encountered, an estimate for the amount of these materials present in the formations sampled can be provided. Using this method allows the designer to communicate the expected geologic conditions to the prospective bidders in a manner that is both definitive and defensible. This paper describes the method as it was used in conjunction with the design of a large diameter sewer tunnel in the Columbus, Ohio area.

Jan 1, 2005

By C. -K. Fang

"Aging effect on the wear resistance of alumina particulate-reinforced 6061 aluminum matrix composites with a block-on-ring wear tester has been investigated. Specimens with various Al2O3 volume fractions of 0%, 10% and 20% were employed in this work. Experimental results indicated that over-aged monolithic 6061 Al had the best wear resistance, as compared with under-aged and peak-aged conditions. For the composite containing 10% Al2O3, over-aging and peak-aging resulted in similar wear resistance, which was higher than that for underaging conditions. For the composite containing a high volume fraction (20%) of Al2O3, the wear resistance reduced with the increase in aging time. Although longer aging time was favourable to the wear resistance of monolithic 6061 Al, it was detrimental to that for the Al2O3/6061 Al composite with high volume fraction of particles. IntroductionMetal-matrix composites (MMCs) have received attention in many engineering applications because of the demands for high specific strength (strength-to-weight ratio) and specific stiffness, good high temperature capabilities and wear resistance. The manufacturing processes of fiber-, whisker-, and particulate-reinforced MMCs have been well developed (Hosking et al., 1982). Because of the reduction in fabrication cost, the applications of MMCs have been widely extended to light weight-bearing sleeves, calipers, automobile parts (brake rotors, drive shafts, connecting rods, piston rings, and cylinder liners), sporting goods, aerospace components, tanks (wheels, speed brakes, and track shoes) and other industrial applications. Among the three types of metal matrix composites, particulate-reinforced MMCs are promising because of their homogeneous and isotropic material properties and low cost. Additionally, they can be formed using conventional metal processing techniques."

Jan 1, 2003

By Gordon Demetrick

3900 Yonge St. was not a typical site on which to build a condominium apartment. A steep hill covered the majority of the site. In order to use as much of this site as possible, the rear of the building was to have nine stores cut into the face of the hill. A permanent shoring system was required as the building structure was not designed to provide sufficient stabilizing elements to support the total earth pressure. The total excavation depth required was 36 m (120'-0") with the upper 12 m (40'-0") to be backsloped. The vertical face of soil to be supported was 24 m (80'-0'). The shoring system originally designed by the Structural Engineer was to support this face by installing soldier piles and inclined earth anchors. During bid preparation it became evident to us that the system as designed would be difficult and expensive to install due to wet soil conditions. An innovative design was required to overcome these problems. Anchor Shoring hired John Stephenson Consultants Ltd. to aid them in accomplishing this goal. After extensive investigation together with The Trow Group, a unique design was proposed which provided a practical solution to the shoring problem.

Jan 1, 1987

By N. C. Clarke, T. Wu, M. le Page, K. J. Henley

In 1994, Gold Mines of Australia acquired the rights to the historic Mt. Lyell copper mine, and commenced a feasibility study into expanding production. The ore was shown in laboratory tests to be amenable to single-stage, fully autogenous grinding (FAG) of underground primary crushed ore, and this route offered the maximum cost savings. Flotation performance was expected to be enhanced. However, batch flotation tests done on pilot-scale autogenously ground ore showed an unexplainable recovery loss of between 1% and 3% Cu. A second pilot plant trial was set up, with the ground product feeding banks of continuous flotation cells. Single-stage FAG, FAG/pebble and FAG/ball circuits were tested. Results confirmed a loss of about 3% recovery with single-stage FAG milling. The FAG/ball circuit eliminated the loss. Analyses showed that autogenous milling probably produced more chalcopyrite/pyrite composites and that recovery of these composites was lower than with ball milling. In size fractions below about 53 microns, where chalcopyrite is well liberated, copper recovery was less affected by milling method and flotation selectivity. It was concluded that for the Mt. Lyell situation, a FAG/ball circuit was preferable to single-stage FAG.

Jan 1, 2002

DML Resources Limited - Mining Division produced over 50 000 oz of alluvial gold in the 1995 - 1996 year from five operations located in the West Coast and Otago Regions on the South Island of New Zealand. DML Resources Limited - Mining Division have a twenty year history of alluvial gold mining development in New Zealand. Recent expansions have seen the establishment of two operations in Chile whilst exploration continues in Bolivia, Peru and Argentina. The overseas growth is based on a stable production base in New Zealand focussed on the West Coast and Southland/Otago present and future operations. DML Resources consider that the mining potential in the Arahura Valley on the West coast will be fundamental to their New Zealand operations for some time. Collectively the plants operating in this catchment are referred to as the Poutini Project. Recent and late Pleistocene gravels derived from the erosion of the Alpine Schists running parallel to the Alpine Fault located on the Pacific/Australian Plant boundary are thought to be the sources of the alluvial gold in the Arahura and adjacent catchments. These gravels have been extensively mined for the past 130 years yielding some six million ounces over this period. Production from the Poutini Project started in 1989 and stood at approximately 35 000 oz for the 1995 - 1996 year. This production was split among three plants each working different areas of the deposit. Recovery techniques from each of the plants are fundamentally the same. Gravels are fed to a floating treatment plant where, following screening, the gold is recovered using jig plants and knudsen bowls. Overburden to wash stripping ratios vary between zero and seven to one with plants treating between 80 and 250 cubic metres per hour. Restoration of the land following mining is undertaken progressively. All land in the Poutini Project area mined to date has been restored to a standard suitable for dairy farming purposes. The Poutini Project is a cooperative venture between the Maori landowners and DML Resources Ltd. The Arahura River has particular cultural significance to the Maori as it is the source of the much valued greenstone or pounamu a type of jade valued for jewellery and tools. The Poutini Agreement was signed in 1989 setting out the role of each party in the mining of the Arahura and adjacent lands. Current exploration and development should extend the resource to allow mining to continue on the Poutini project for an additional three to five years at current gold prices. Production within new Zealand beyond this point may be compromised by increasing difficulty in gaining access to prospective areas within New Zealand, lowered margins due to high New Zealand dollar exchange rates and the overall lowering of alluvial headgrades throughout the West Coast and Otago/Southland regions. To counter these effects DML has continued to improve on operational efficiency and performance monitoring to optimise the mining practices used. This paper detains the background to the Poutini Project, the geology, plant and equipment used together with descriptions of the current mining methods employed.

Jan 1, 1996