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This presentation is a 20 minute snippet of my professional career, and my progression in the mining industry, from a lazy uni student to an up-and-coming blast engineer in the middle of a mining boom.My name is Daniel Hepburn and I am a blasting engineer for Orica Mining Services. I graduated from Royal Melbourne Institute of Technology (RMIT), in Melbourne in 2003. I completed both of my final year projects with Orica Quarry Services and was offered an assistant shotfiring job, which I accepted and worked for eight months. Having missed the cut-off date for the Orica graduate program, I planned to work with Quarry Services until the following year where I hoped my marks and the experiences I had gained would secure a graduate position. I didnÆt have to wait long, as in August of that year, I was offered (and I accepted) a graduate position in Perth as a technical services engineer for Orica Mining Services. The Orica graduate program is based over two years, and consists of real roles from day one; however, there is also opportunity to fast track the program for high performers. There is a structured rotation, from site to site, interstate or even international if you are so inclined. This includes the backpacker program, which allows graduates to experience the Orica culture in countries of their choice. There are also opportunities to try cross-functional roles in the different Market segments within Orica. I was lucky in that I knew what I wanted to do and where I wanted to work, so I stayed in Perth for my entire graduate program. I was also lucky enough to be fast tracked and finished my graduate program in 15 months. At the end of 2005 I accepted a position as an open cut blasting engineer based in Perth and even in such a short period of time I have already completed a number of major accomplishments. Some of these accomplishments are described below. This paper is available as a PowerPoint presentation only.

Jan 1, 2006

By H. Boyd

Fluid energy grinding, or jet pulverization, refers to the process of entraining solid particles in high velocity gaseous or vaporous streams and reducing their size by impact and attrition against other particles or some sort of target. Since all desired size reduction is not achieved in one pass through the zone where energy is applied, some form of classification is necessary to return oversize particles to the grinding zone for further size reduction. Applications Fluid energy mills have normally been used to produce products where the particle size is basically finer than 325 mesh. Products having particle size distributions with a maximum size of 4 or 5 µm, and with a high percentage finer than I µm, can be produced using fluid energy mills. More recently, some fluid energy grinding units have been applied economically to produce ground products with 1 or 2% coarser than 200 mesh. It is also possible to consider usage of a jet-pulverizing zone, without the usual integrated air classi¬fier, operated either in open circuit or in conjunction with a screen. Feed sizes to be delivered to the fluid energy mill depend on the material involved, the type of jet pulverizer used, the finished product size requirement, and the upstream process. In some units feed sizes up to l in. or larger can be accepted, but practical economics usually require the starting material to be -4 mesh or smaller and some pulverizers are typically fed at 20 mesh top size. It is not unusual to find feed materials at essentially -325 mesh when extremely fine products are needed, since capacities are improved with finer feeds. Conventionally the fluid energy grinding process has been used for relatively soft and nonabrasive materials. This includes very low¬melting-point and temperature-sensitive materials or coatings, since there is no measurable temperature rise during fluid energy milling. More recently, however, jet pulverizers are being used on highly abra¬sive materials such as silica, feldspar, glass, zircon, calcined alumina, coke, boron carbide, and similar materials. Since the primary energy application is by impact of particles against themselves, there is a low rate of wear resulting in a small amount of product contamination and in low maintenance costs. Usually the fluid energy pulverizer produces a more narrow particle size distribution than other mills provide, and this is useful where such a requirement exists. It is possible, within limits, to adjust classifi¬cation and other functions of the overall fluid energy system to vary the particle size distribution curve and thereby approach the broader distribution obtained from other grinding methods. By controlling the temperature, composition, and humidity of the fluid used, it is possible to incorporate other functions with the size-reduction process. These include drying or adding moisture, coating, mixing and blend¬ing, and even oxidation or reduction and other chemical reactions or their inhibition. The finished product is discharged in the fluid stream and is conveyed pneumatically to the desired point, where a suitable dust collector must be provided. Operation and Mechanical Features One of the earliest fluid energy mills is the Micronizer now manu¬factured by the Sturtevant Mill Co. Similar units are also manufac¬tured by Jet Pulverizer Co. and others. As shown in Fig. 81, the micronizer consists of a shallow circular grinding chamber with noz¬zles arranged at the outer periphery to discharge tangentially inward. Fluid (usually compressed air or superheated steam) is provided to the nozzles from a manifold at pressures normally in the range of 100-150 psig and at temperatures up to 800°F or higher, depending on the raw material, required results, and economic factors. The com¬pressible fluid expands to high velocity through the nozzles and gener¬ates a spiral flow pattern in the grinding chamber, and discharges

Jan 1, 1985

By H. J. White

Haynes International, a world leader in the manufacture and production of nickel, and cobalt base alloys has invented and developed a low cost high temperature material, with a unique combination of superior oxidation resistance and weldability/ fabricability. HAYNES® HR-224TM (Ni ? 27.5Fe ? 20Cr ?3.8A1 ? 0.3Si ? 0.3Ti) forms a planar/ continuous/ adherent aluminum oxide film at high temperatures which has been shown to effectively limit chromium poisoning in solid oxide fuel, cell, systems. A 20,000 pound vacuum induction melted (VIM) + electroslag remelted (ESR) heat has been melted and converted into various product forms: sheet, plate, bar, welded tubing, wire, etc. The alloy was designed for service in severely oxidizing environments recuperators, automotive catalytic converters, wire strand annealing furnace tubes, etc. and has been of great interest to solid oxide fuel, cell, manufacturers as a materials of construction in balance of plant (BOP) design. This manuscript presents the physical, properties, mechanica, properties, and oxidation resistance of the alloy compared to other materials being considered for solid oxide fuel, cell, design

Jan 1, 2010

By B. Stewart

Recent ore pass failures have underlined the need for improved designs, standards, structural monitoring methods, and better hang up prevention and removal techniques. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) are investigating methods to improve safety during transport of ore in ore passes. Design criteria and hang-up prevention and remediation strategies involve studies of the effects of static and dynamic ore and waste rock loads on chutes, walls, gates, and support structures. Particle flow analysis methods were used to simulate the response of various ore pass designs to a wide range of ore loading conditions. A full-scale mock-up of actual ore pass and chute assemblies was duplicated and tested for load response. Data from a particle flow code and the mock-ups were com-pared. Loads on an active ore pass chute were measured.

Jan 1, 1998

United Engineering Trustees, Inc. WILLIAM H. BASSETT H. G. MOULTON R. M. ROOSEVELT The Engineering Foundation GEORGE D. BARRON E. DEGOLYER R. M. ROOSEVELT Engineering Societies Library Board ROBERT PEELE H. K MASTERS A. B. PARSONS, Ex-officio F. F. SHARPLESS R. H. SWEETEST

Jan 1, 1934

By R. V. Tomkins

Introduction In the past fifteen years, bentonite production in the United States has increased very rapidly. From l50,000 tons in l934, it rose to 400,000 tons in l 942 and to a record 920,000 tons in 1948. Occurrences of bentonite ?in western Canada were described in the early part of the century by Ries and Keele (3), Ells (2), Spence (4). and other officer of the Dominion Department of Mines, and, in Saskatchewan, Professor W. G. Worcester (6), of the University of Saskatchewan has explored and carried out tests on deposits of the material at various times during the past thirty years. Nevertheless, Canadian developments have not kept pace with those in the United States. Exact figures for total Canadian production are not released, but it is probably under l0,000 tons annually. There are a great number of uses for bentonite, but in the United States three alone account for 90 per cent of the consumption. These are for drilling gel, foundry sand bond, and oil decolorizer. The tremendous oil exploration programme on the Canadian prairies has increased the possibility of an adequate domestic market for drilling gel. Therefore, in Saskatchewan, our efforts have been directed mainly to the production of a good drilling gel, with a minor part of the project devoted to activation of bentonites for oil decolorizing.

Jan 1, 1952

By M. J. Saarivirta

A high-purity copper-zirconium alloy system was imesti-gated. The zirconium content of the alloys studied varied from 0.003 to 0.23 pet. The solid solubility of zirconium in copper and some physical and mechanical properties of the alloys have been determined. By proper heat treatment, Cu-Zr alloy can develop a high electrical conductivity and resistance to softening at temperatures up to 500°C (930°F). This combination of desirable properties makes this alloy superior, to other com-merzcrrl copper base alloys for- use in the electrical conductor field. DEMAND for high conductivity copper alloys that retain their mechanical properties at elevated temperatures is growing rapidly. At present, copper-base alloys such as copper-silver and copper-chromium are used where these characteristics are required. As an example, commutators in electric motors are often made of these alloys. However, the life at elevated temperature of commutators made of copper-silver alloys is much shorter than the life of the same part made of copper-chromium and copper-zirconium alloys. Copper-silver alloys are subject to creep and subsequent failure when the service temperature exceeds several hundred degrees centigrade. Use of copper-chromium alloys has been known for the past several years, but little information is available in the literature concerning the properties of alloys in the copper-zirconium alloy system. Some work had been directed toward determining the solubility of zirconium in copper as well as determining properties of the Cu-Zr alloys. These investigations have revealed the superior high-temperature and electrical conductivity properties of copper-zirconium alloys over copper-chromium alloys. The United States Metals Refining Co., Carteret, N. J. has recently produced OFHC R copper-zirconium alloys for experimentation and evaluation. Because OFHC R copper contains no appreciable oxygen, no harmful oxides are formed and the full benefit of Zr as an alloying addition is obtained. This paper describes the results of this work. It contains room-temperature and some high-temperature data which have been obtained after various processing techniaues. Actual elevated temperature properties are being determined and will be reported in a separate paper. Preliminary results obtained at elevated temperatures suggest that the Cu-Zr alloy is superior to other high conductivity copper-base alloys. WORK PROCEDURE The high-purity oxygen free (OFHC R) copper-zirconium alloys with zirconium content ranging from 0.003 to 0.23 pct were cast into 4-by 4-in. wirebars by both continuous casting and conventional casting methods. Zr was added in the form of a master alloy containing 30 pct Zr and 70 pct Cu. Castings were analyzed for zirconium and nine bars containing various amounts of zirconium were selected for this study. The results of analyses and the sample numbers are given in Table I. Typical analyses of OFHC R copper are also shown. The following properties were studied: A) Solid solubility of zirconium in copper. B) Effect of zirconium on properties of copper. C) Effect of combined working and heat treating on properties of Cu-Zr alloys. The solid solubility of zirconium in copper was determined by metallographic techniques. Specimens for this phase of the investigation were hot rolled at 900oC (1650oF) to 0.250-in. rod. The rolled rods were cut into 2/3-in. long specimens and solution annealed at 950 °C (1740°F), 980°C (1795 °F). and 1020 °C (1870 °F) for 6 hr and quenched in water. In order to find the solid solubility limits at lower temperatures, the homogenized specimens were reheated at various temperatures for 1 hr and quenched. The physical and mechanical properties were determined on 0.250 in. rod, 0.132- and 0.081-in. wires. The wires were cold drawn from the 0.250-in. rods after they were solution annealed at 980 °C (1795°F) and quenched in cold water. Mechanical and electrical properties were determined on cold drawn and

Jan 1, 1961

By K Rees

In the ideal world of an underground mining engineer, all narrow vein orebodies would be perfectly straight and continuous, thus would be a dream to mine. However, this is usually not the case. Narrow vein orebodies generally occur in association with shear zones and while shear zones do form linear trends, they most commonly preserve undulating expressions that need to be closely monitored, particularly when overprinted by post-formed structures. The surge in mines using fibrecrete as a primary form of ground support effectively reduces the time available for geological interpretation down to a 30 minute window between bogging and shotcreting. Thus, if the quality of the data collected is not up to scratch, then there is only a limited ability to reassess using 2D face photographs. To negate this, Xstrata Nickel AustralasiaÆs Cosmos mine has upgraded its data collection procedure. Geological information is now collected using photogrammetry survey, producing 3D images of the drive. Once created, the digital image of the drive is loaded into Vulcan, thus enabling geological interpretation to be carried out along entire drives, between levels and in association with all other data (eg drill holes, seismic data, etc). In addition to this, the 3D image can be used to accurately model the location of the ore, enabling stoping panels to be confidently positioned to maximise grade and minimise dilution. However, with the focus at Cosmos changing from narrow vein mining, to bulk mining methods in a more geotechnically complex terrain, the use of the 3D images has become paramount in understanding the structural geometry. Continual interpretation of the data has enabled drive profiles to be maintained through the increased use of ground support in poor ground and the redesign of development to enable optimal intersection of structures. Nevertheless, while the collection of quality data is important, it is only the effective use of the data, which enables significant gains in understanding.CITATION:Rees, K, 2012. The benefits of using photogrammetry in the geological interpretation of the Cosmos nickel mine, in Proceedings Narrow Vein Mining 2012 , pp 145-148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By J. A. Ede

The property of the Spring Valley Coal Company, situated in Bureau county, Ill., comprises something more than 30,000 acres of coal-lands, on which have been opened four mines, designated as Nos. 1, 2, 3 and 4. Figs. 1, 2, 3 and 4 are plans of the first three; and Fig. 7 is a view of the surface-plant at No. 4, the workings of which it is not necessary to illustrate, as this mine has been practically merged in No. 2. No. 4 shaft is only 500 feet from No. 2, and both are ventilated by the same fan, and are in the same circle of air-supply. In speaking of No. 2, we now include No. 4. The system pursued in all the mines is " long-wall advancing," and the shafts are all vertical. The seam worked is locally and commercially known, in the Illinois series, as No. 3; but its position in the geological series is that of No. 2. It averages in thickness about 42 inches, arid has no partings, but mines in rectangular lumps, which stand a large amount of handling before breaking. An analysis made from Colliery No. 1 gave the following : Per cent. Moisture,.......... 1.45 Volatile combustible matter,.47.27 Fixed carbon,.........41.97 Sulphur,.........2.46 Ash,....... .. .. .. 6.85 Plate 6 shows a photographic view of this seam. The staff seen in the view is 37 inches long. The table on page 188, recorded in my office, which I presume to be correct, may be of interest. The bottom is fire-clay, varying in thickness from 6 to 24 inches. It affords what is considered good mining-ground. The roof immediately above the coal is a dark shale, lying in small bands, from 4 to 9 inches in thickness. Between the

Jan 1, 1900

By E. S. Shaw

Utah continues as a very unimportant factor in oil and gas production. During the year 1933 there were no developments of noteworthy significance. There were no completions of either producers or dry holes during the year. The only commercial production in Utah has been from the five fields listed in Table 1 and mentioned briefly in the following paragraphs. Virgin Field.—Oil was first discovered in 1907 in a well drilled in sec. 13, T.41S., R.12W. Of the first 15 wells drilled, all but three were failures. In 1920 production from four wells from 550 to 600 ft. deep was about 20 bbl. per day. San Juan Field.—The majority of drilling in this area was done during the years 1908 to 1911. Probably the first commercial well in the field was that drilled in NW.$i sec. 6, T.42S1 R.l9E., in 1909. Farnham Dome.—The discovery well was drilled by the Utah Oil Refining Co. in April, 1923. A number of years later a second well was drilled by The Carbon Dioxice a mica1 Co., the present operator, which markets the gas in the manufacture of "dry ice" and allied products. The eslimated production, as indicated in Table 1, includes 500 million cubic feet estimated to have been lost while drilling the discovery well. Cisco Dome.—The discovery well was drilled by The Utah Oil Refining Co. in November, 1924. The Crystal Carbon Co. markets the gas in the manufacture of carbon black. Ashley Valley Dome.—The discovery well was drilled by the Utah Oil Refining Co. in April, 1925. The Uintah Gas Co. markets the gas in Vernal, Utah, for fuel. Woodside Structure.—In February, 1924, gas was discovered in a well drilled by Utah Oil Refining Co. in sec. 12, T.l9S., R.l3N., on the Woodside structure. This gas is reported to contain an appreciable amount of helium. It is being held as a helium reserve by the United States Government. Salt Valley Structure.—The test of the Utah Southern Oil Co. in sec. 31, T.23S., R.21E., on the Salt Valley structure has been shut down for some time at 6120 ft. This test has passed through more than 5000 ft.

Jan 1, 1934

By Bill Dershowitz

Consider a deep gold orebody with grade of 4 g/t (0.11 oz/st). At the time of this writing, with gold prices at historic highs, it could be a good, but not great, prospect. But if it is a vein deposit, and those veins are 200 g/t (5.8 oz/st), it would be significantly more attractive if there was a way to produce directly from those veins, leaving the rest of the rock in place. [Figure 1 The red around each of the four injector wells shows areas of high pressure, where the lixiviant fluid is pumped into the rock mass, with orange and yellow indicating dissipated pressure. The black lines indicate some of the fracture pathways through which the lixiviant, with absorbed metal, flows toward the central recovery well where low pressure is indicated in blue. Lixiviant is pumped out through the recovery well. Image courtesy of Golder Associates.] There is a way to do this, in situ leach (ISL) or solution mining. It has been a viable commercial technology for more than five decades.

Jan 1, 2011

The paper concerns an unconventional, yet promising, use of waste magnesite dust and fines. In India a significant amount of this dust is generated from some of the integrated iron and steel industries, refractory and cement plants, during calcination of raw magnesite. However. it is possible to utilize this dust, which is normally a waste, conveniently and economically for the production of magnesium. chemicals. A bench scale study was carried out to determine the rate of formation of sulfated com¬pounds of Mg.Ca,and Fe, inter alla, present in the dust system containing MeO constituents (in which Me=Mg.Ca,Fe,Si,Al etc.) Effects of various process parameters, which affect the reaction rate as also the purity of the product ,were also studied. Some work carried out to develop the process flow charts involving the salient steps to produce magnesium chemicals commercially is reported in the paper .

Jan 1, 1992

By R. P. King, L. C. Woollacott

To date developments in the simulation of carbon-in-pulp (CIP) adsorption circuits have focused primarily on the modeling of adsorption. This series of three papers describes a development in a direction that has received less attention, i.e. the need for a detailed description of the movement of carbon and slurry in continuous CIP and carbon-in-leach (CIL) plants. A new simulator has been developed based on the population-balance approach for modeling the movement of carbon and slurry. Existing adsorption and leaching models are evaluated in this paper in order to establish which are appropriate for use in the new simulator. The details of the simulator are given in Part 2 of this series.

Jan 1, 1990

By D. J. McAdam

IN a recent survey of the literature, the author has found evidence incompatible with prevalent views regarding the technical cohesive strength and yield strength of metals. Some of the evidence regarding the technical cohesive strength was presented in a previous paper,21 and views were presented that are believed to be in better accord with the evidence. In that paper, it was shown that the technical cohesion limit (contrary to prevalent views) varies with the combination of principal stresses,† and that the influence of plastic deformation on the technical cohesive strength is not in accordance with prevalent views. In this paper, consideration will be given to both the technical cohesion limit and the yield stress as affected by the combination of principal stresses. Evidence will be presented that the variations of the yield stress and the technical cohesion limit with the combination of principal stresses are not in accordance with prevalent views. Consideration will also be given to ductility and work-hardening capacity, which depend on the initial difference between the technical cohesion limit and the yield stress. By the "technical cohesion limit" is meant the mean stress at actual or potential* fracture. An example of a technical cohesion limit is the "true" breaking stress of a tension-test specimen, the breaking load divided by the sectional area at fracture. The cohesion limit thus obtained for a ductile metal, however, has been greatly altered by the plastic deformation. It is important to consider the cohesion limit of the metal prior to this deformation, and the variation of the cohesive strength with plastic deformation. The relation between the cohesion limit and the corresponding flow stress† determines the ductility of a metal and the energy that it will absorb before fracture. In this paper, as in the previous paper,21 tensile stresses will be viewed as positive and compressive stresses as negative. The algebraically greatest principal stress will be designated S1, the least principal stress will be designated S3, and the intermediate principal stress will be designated S2. In the previous paper, attention was confined to stress combinations with two of the principal stresses equal (with the intermediate principal stress S2 equal either to S3 or S1). In this paper, consideration will also be given to the effect of stress combinations with all three principal stresses unequal. In the earlier sections of the paper (pp. 1 to 14), attention will be confined to stress combinations with

Jan 1, 1942

By Guihong Han, Wei Wang, Chaolei Lv, Yongsheng Zhang

Silica aerogels are promising in many applications because of their excellent properties. However, the real applications of pure silica aerogels are limited because of their fragile network structure. We have prepared silica aerogel composites using humic acid as a composite material for improving the performance of silica aerogels and valorization of humic acid. The silica hydrogel composite was prepared using sodium silicate as a precursor and humic acid as a composite material by acid-base catalysis and sol-gel method. The hydrogel was followed by freeze-drying to obtain composite aerogel. The microstructures, specific surface area, and functional groups of silica and composite aerogel were characterized using scanning electron microscope (SEM), brunauer-emmett-teller (BET) and fourier transform infrared spectrometer (FTIR). The results demonstrated that the specific surface area of the silica composite aerogel was 307 m2/g under the condition of pH at 6, the mass ratio of silicon to humic acid (HA) at 3.82 and the molar ratio of N, N-dimethylformamide (DMF) to silicon at 0.9. X-ray diffraction (XRD) showed that the silica (composite) aerogels were amorphous. Thermogravimetric analysis (TGA) revealed that the silica aerogels lost weight from 150 to 250 °C and humic acid decomposed between 350 and 500 °C, and then the mass of the sample remained stable.

Mar 1, 2018

By Wasyl Kunda

High grade jig and low grade flotation concentrates used in the following experiments, are produced from silver ore at the mine. The study was carried out to recover the silver and other metals from these concentrates by hydrometallurgical methods. The concentrates were subjected to two stage oxida¬tion leaches in a HNO3-H2SO4 medium. The dissolved metals were recovered by selective precipitation of: (a) silver chloride, (b) iron-arsenic-bismuth residue, (c) copper sulphide, (d) cobalt-nickel sulphide. The effluent solution contained only ammonium sulphate and ammonium nitrate. The silver chloride was further processed to the high purity silver powder by the AgCl ? Ag2S ? Ag2SO4 ? Ag° route. The recovery of silver from the concentrates was over 98% and other metals from 95 to 99%.

Jan 1, 1984

"This model specification includes sample text shown in normal font with commentary in italics. The commentary is intended to highlight project-specific items the specification writer should consider during development of the specification. In some sections, typical values are presented to indicate common practice, and these values may be changed to reflect project-specific requirements. The commentary should be removed before using the specification for a project. 1. SCOPE The work consists of designing, furnishing, installing, and testing helical piles used to support foundation loads (compression, tension and lateral), and any ancillary materials (e.g., load transfer devices, etc.) according to the project plans provided and these specifications. Unless otherwise noted, the installing contractor shall provide all labor, tools, equipment and materials necessary to install the required piles. The parties referred to in this specification are as follows: • The Owner is the property owner. • The Owner’s representative is the individual or firm hired by the Owner to design and oversee the overall project. • The pile designer is the individual or firm generally hired by the installing contractor to design the helical piles. • Installing contractor installs and tests (if necessary) the helical piles, and possibly tasks associated with the project. It is important to clearly define the roles and responsibilities of every party on each project to promote good communication and reduce potential for contractual misunderstandings. Different types of contractual vehicles (design-build, value engineering, etc.) require different roles and responsibilities for the various parties, which should be considered in specification development. The Owner will provide suitable access to the construction site for the installing contractor’s personnel and equipment. Unless specifically noted otherwise in the contract documents, the Owner will remove and replace any structures, utilities, pavements, landscaping or other surficial improvements in the work area as necessary to facilitate the work. The Owner will be responsible for overall construction oversight to minimize potential for developing unsafe conditions. The work may include post-construction monitoring of pile performance if required by the Owner or the pile designer to confirm performance of the piles subsequent to their installation. The work may also include installation of additional piles if the initial installation does not meet specified capacity or performance requirements. Responsibility for providing subsurface investigation shall be addressed in the bid documents. The Owner is responsible for providing to the installing contractor all available subsurface soils, rock and groundwater information and geotechnical testing data."

Jan 1, 2015

By E Deucker, A White

Gold Fields Australia (Gold Fields) has identified that improving productivity through more detailed shift planning and operational control of mining activities is a key driver to the success of their business. The Hamlet mine was chosen as a pilot site to trial a system that would allow production engineers and shift bosses to align the execution of short-term activities with the longer-term goals of the organisation.Gold Fields partnered with Deswik to introduce an on-site, collaborative, web-based system to allow mine planners to quickly build-up a detailed, activity-based, shift schedule for the coming week from the 13-week plan. Multiple stakeholders could then review and alter the plan, and then track and manage the execution of the activities.The system is designed to be integrated with production data capture systems to allow tracking of progress towards completion for each activity, as well as to plan and monitor the equipment operating in the mine. Integration of systems allowed engineers to use the large quantities of production data being captured to make informed decisions in the operations environment.The system replaced a complex set of spreadsheets that required expert users in Gold Fields to maintain. By capturing the data in a central database, the planning process is transparent and historic data from the execution of activities is available for analysis to improve productivity in the future.The system has ensured that the highest priority and critical path activities for the business are completed at the right time, improving the efficiency of operations.CITATION:Deucker, E and White, A, 2017. Productivity improvement through collaborative shift planning and tracking, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 225–234 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

The Macraes Mining Company Limited was listed on the New Zealand and Australian stock exchanges in January 1990, and the proceeds of the float were used to purchase a 70 per cent interest in the Macraes Gold Project, previously owned by BHP Gold Mines (NZ) Limited. Macraes Mining has had a 30 per cent interest in the project since May 1984, when it was incorporated. Project financing in the way of a gold loan was secured in February 1990 and construction commenced shortly afterwards. The mine construction activities were completed within nine months and the mine commenced operations in October 1990.

Jan 1, 1991

By Dino Kartofilis, Rick Deschamps, Giovanni (John) Bonita

"Anew condominium complex in Arlington, Va., presented some formidable constraints. One was the requirement for a permanent retaining wall to support a 48.5-ft (15-m) cut and an existing 16- story building on top of the slope. Another was the adjacent property owners’ refusal to allow tieback anchors to encroach on their property. The General Contractor (GC) proposed an innovative design incorporating vertical concrete load-bearing elements (LBEs) supported by post-tensioned tiedowns. The owner accepted and the project was successfully completed in 2007.The original designer had proposed a system that included a temporary, raked soldier pile and lagging wall and a permanent cantilever retaining wall with a large piled footing. The system was potentially costly and its constructability questionable.The GC then asked for a design-build alternative to reduce costs and enhance the schedule. The first idea was a diaphragm wall with vertically anchored T-sections. However, configuring a crane to excavate perpendicular sections using grab equipment seemed impossible. There were also utilities approximately 25 ft (9 m) from the existing building, two tiered retaining walls down the slope and a large swimming pool at the base. However, the GC was committed to providing a stable bench 20 ft (6 m) wide along the wall alignment to support the crane.The design evolved to single bite panels using diaphragm wall technology, commonly called LBEs, or barrettes, when they carry vertical loads. For this project, 44 LBEs were horizontally spaced at 9 ft (2.75 m) on center, oriented perpendicular to the wall, extending into bedrock and anchored vertically on the upslope side to resist overturning moments. They were essentially large soldier piles that provided both temporary and permanent support of excavation.An unusual formal agreement was established with the GC to complete the work based on pricing, and prior to completion of final design. This arrangement allowed for an exchange of ideas that increased project efficiencies and lowered costs — without the fear that design concepts would be “shopped” to competitors."

Jan 1, 2009