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By E Skinner, G Lane

Project delivery strategies are determined by project context, business case requirements, scale of project, market conditions, ownerÆs capability and preference, contractorÆs experience, resource and skill availability, project location and type of project or facility.Successful project management requires the setting of coherent, effective and realistic business objectives and success criteria. The management team needs to lead, prioritise, resource, align, plan, track and communicate the processes that enable the realisation of these business objectives and success criteria.For any given project there is a unique balance between selection of a simple project delivery strategy that minimises interfaces and a complex strategy that necessarily engages the use of expertise and experience from numerous parties. The right balance for a project between these "book-end cases" is a function of how the project owner or managing contractor defines its objectives and chooses to manage risk, cost, schedule and project quality, in the context of the conditions affecting the project.Selection of an effective project delivery strategy requires a detailed appreciation of the range of external and internal environmental / shaping factors which influence the project. These factors include the project constraints imposed by the business, market or operational environments and the selection of an effective mix of primary (head contract), secondary (mix of vertical and horizontal packages) and tertiary (type of individual contract) strategies. The selection of the primary, secondary and tertiary strategies also shapes the project, the size and responsibilities of the ownerÆs team and the framework for delivery of outcomes.How does an owner or prime contractor decide? What is the optimum for a given project? Those with operations management backgrounds will have different views to those with project and construction management backgrounds.Is the simplest practical approach the best approach? Each and every interface needs to be managed.The owner will want a very experienced team that is engaged directly with the owner. The team will have a track record of successfully performing projects using contractors skilled in their respective disciplines and selected using competitive tendering on brilliantly designed scopes of work and good contract terms, with a fully defined project scope and appropriate schedule, for which all significant risks have been addressed and no scope changes are outstanding. Budget and schedule will be expected to have been developed with a full understanding of the scope, situation, risk management requirements etc.The problem is that these conditions rarely exist. The challenge in selection of a project delivery strategy is to resolve how best to address the inadequacies between the ideal case and the present reality. The mechanism for addressing the inadequacies defines the likely outcome of the project.CITATION:Lane, G and Skinner, E, 2013. Project delivery, in Proceedings MetPlant 2013 , pp 50-65 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By R. H. Grau, S. B. Robertson, R. B. Krog, T. P. Mucho

Due to the difficulties of ventilating large opening stone mines, the effective dilution of diesel particulate matter and noxious gases has often been problematic. Since stone mines have large openings that develop low air resistances, and propeller fans are designed for low pressure-high volume applications, main mine propeller fans may be a feasible option for ventilating underground stone mines. This paper describes the results of a case study where researchers from the National Institute for Occupational Safety and Health have demonstrated that significant increases in total mine airflow can be achieved and the ventilation improved in a large-opening stone mine by replacing an axial-vane mine fan with two 12-ft diameter propeller fans and adding a line of stoppings. In this study, the use of the propeller fans more than doubled the air quantity from 300,000 cfm to 750,000 cfm, while operating at 50 horsepower less than the original axial-vane fan.

By Les Gutzwiller

Fan applications in the mining industry have changed during the last 70 years. In 1922, J.R. Robinson authored a technical volume entitled Practical Mine Ventilation. At that time, atmospheric control had only recently shifted from natural to mechanical. The large, mechanical draft fans that were used then were centrifugal. The fans ran at low speeds, about300 rpm. Most were steam-engine driven. In the late 1920s and early 1930s, mines became larger, increasing the pressure and volume requirements of the fan equipment. Axial fans were designed to run at much higher speeds (710 to 880 rpm) and were driven by electric motors. They were also smaller and less expensive to install than the cumbersome centrifugal units. However, changes in mining have resulted in progressively higher static-pressure requirements. So centrifugal fans are once again proving to be a good choice.

Jan 1, 1999

By E. Douglas, V. M. Malhotra

"This report presents the results of a laboratory study undertaken to evaluate ground granulated blast-furnace slag from Algoma Steel Corporation, as a replacement for Portland cement in cemented mine backfill. The evaluation was based on the results of compressive strength tests performed on cylinders cast from mixtures made with a granulated blast-furnace slag and tailings from four different mines in the Sudbury basin. Various percent¬ages of slags and various binder to tailings ratios were used.Tests results show that, in terms of compressive strength, the slag performs as well or better than Portland cement as the binding agent in cemented mine backfill. Lime was found to be a poten¬tially good activator for ground granulated slag in mine backfill applications.A field test was conducted at one of the mines, consisting of placing a mixture of 95.5% ground granulated slag and 0.5% lime into a stope, and inspecting the floor slab as it hardened. The slag performed as expected, considering the backfill mixture proportions used and the preparation of the test site."

Jan 1, 1989

By R S. Hamilton, S R. Grobler, M E. Greenway

The progressive development of underground mines frequently requires increased ventilation flow rates through mine shafts that were originally designed for lower rates. Where these shafts are equipped with conveyances running on rope guides, the higher air flow rates adversely affect the lateral motion of conveyances and could cause conveyances to collide with the shaft walls or with one another. Hence the safety impact of higher flow rates requires proper assessment. This can be undertaken by use of computer simulation models to predict the dynamic motion of the conveyances during hoisting. It can also be undertaken entirely by field testing, or using a combination of simulation and field testing. This paper discusses these techniques and makes cautionary remarks about setting an absolute generic maximum flow velocity for all shafts. Approaches to assess existing shafts for increased ventilation flow rates are also discussed.CITATION:Greenway, M E, Grobler, S R and Hamilton, R S, 2017. Safety impact of increased shaft ventilation on rope guided conveyances, in Proceedings Australian Mine Vent Conference 2017, pp 261–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

THE treatment by chlorination of the Mount Morgan Gold Mining Company's ores was first accomplished, early in 1886, by a works having a capacity of 25,000 tons per annum. Shortly afterwards another works was established, capable of dealing with 50,000 tons per annum. The extraction of gold was originally successful and satisfactory, but running expenses were high, averaging £2 19s. 6d. per ton of ore treated. These works were believed to be the largest chlorination pJants in the world at that time. As might have been expected, the mechanical details and chemical process had not been perfected, and, moreover, both works were hurriedly built, and operating expenses were not then considered of such prime importance, as the ore at that time was of very high grade the large quantities of low grade ore since dealt with not being then considered, since the bulk of it was not even known to be in existence.These two works consisted of lock-breakers, high speed rolls, screens, elevators, &c., for crushing; a large number of small handrabbled reverberatory furnaces for roasting; one-ton chlorination barrels and three-ton leaching vats for chlorination.

Jan 1, 1910

By Patricio Santis, Jacopo Seccatore

Artisanal and Small-scale Mining (ASM) is a prominent activity in the extractive industry: considering only gold, it produces about 20% of world market supply. Despite this fact, ASM is generally associated with negative aspects of its environmental impact, and operational research is generally neglected. This paper emphasizes the peculiarity of the drilling and blasting systems of small underground mines in selected South American Countries. Such Countries, while having large mineral deposits and well recognized large-scale mining activities, at the same time still present on their territory ASM activities that are archaic, highly inefficient and dangerous for the safety of its operators. This paper documents drilling and blasting activities from gold mining in Ecuador and Chile. First, are described the outdated and often non-rational techniques employed by miners, to provide a general framework of the current methods. Then, it is shown what can be improved and how the current methods can be modified. Finally, are shown some field applications and the comparisons of the results obtained. One case shows how blast pull efficiency can be increased of from 82% to 98% by changing non-rational applications of explosive products. Another case shows how, by rationalizing blast designs, drilling and blasting costs can be reduced by 9% per month, the advance by blasting increased by 29% and the blasting efficiency increased from 70% to 90%. Finally, it is concluded that examples of application show how operational improvements are easily applicable on the field, relying only on tools and resources of artisanal mining, but combining solid engineering bases with confidence-gain and respect for the experience of the miners.

By Pupazzoni P. D, Meissner D. C

Incorporating an iron ore pelletising plant, a MIDREX'"' Direct Reduction Plant, and a mini mill, the conversion of iron ore fines to high- quality steel slabs in Western Australia is among the lowest cost routes in the world. The cost and availability of iron ore and natural gas, government support, and proximity to the growing Southeast Asian market all contribute to the competitive position of the area. Owing to the lead-time required, this is an ideal time to develop a new project to supply semi-finished steel to Asia for rolling to a finished product. A project contracted now will start up in about three years, when the market should have recovered.

Jan 1, 1999

By Douglas Bartley, Jay Elkin

The state of Pennsylvania was at one time one of the leading coal producing states in the east. However, legislation and industry trends over the last 10 years have adversely affected the amount of bituminous coal mined in Pennsylvania and the whole eastern United States. The application for and approval of a new mining permit is a very costly and arduous task. When a new mining operation is established it is crucial that nothing within the operator’s control causes the operation to stop producing. This paper discusses the action taken by a small mine in Pennsylvania when their blast induced vibrations rose to levels that typically would have resulted in a total mine shut down by the regulatory body governing such operations.

Jan 1, 2003

By Dilip Khatri

Helical pile anchors have gained acceptance over the past sixty years. Most recently they have been commonplace in the 20th century for the power utility industry in anchoring transmission towers, equipment platforms, street lighting, telephone poles, and radio tower applications. They have a strong proven industrial track record in these industries. As the cost of conventional deep pile foundations rises, the practical benefits of helical pile anchors becomes evident as a practical alternative. Noted for their uplift capacity, helical piles demonstrate equally strong compressive capacity as a structural foundation element. This paper summarizes the history, practical benefits, and technical requirements for helical piles. Significant structural testing has been completed at various universities. The practical benefits of these tests are discussed. One case example of proven performance is presented to demonstrate the advantages and disadvantages of helical pile anchors as suitable foundation elements.

Jan 1, 2003

By F. Terblanche, M. Holton, A. Kruger

The paper presents an optimal mine planning system designed to simultaneously optimize all the underground mines of large South African gold and platinum mining corporations. The system, code named PlanIT-OPTIM, is a multi-stage solution involving the use of adetailed 3D CAD-based mine planning system (CADSmine™V4). The mine design and scheduling rules defined in CADSmine™ are responsible for simulating mining sequencing, rock mechanics, and ventilation, etcetera. Feasible production ranges generated by CADSmine™ and various high-level mathematical models are used as inputs to a mathematical optimization engine. The optimization engine produces optimal production profiles (i.e. key business indicators such as tonnages, mineral and areas extracted per time period) by maximizing net present value. Other objectives such as profit continuity, production continuity and maintaining available reserves can also be specified as optimization criteria. The final step in the PlanIT-OPTIM process is to convert the optimal production profiles into practical and attainable business plans. This is achieved through the CADSmine™ Detail Optimization Engine that modifies the original CADSmine™ schedule to match the optimal production profiles. With current methods it is an impossible task to find the best business plan for a mining corporation in any reasonable period of time should conditions change (e.g. gold prices, exchangerates, grade estimates, etcetera). The fast turn around time achieved through PlanIT-OPTIM makes it possible to do several ‘what-if’ scenarios in a reasonably short time. PlanIT-OPTIM has already been used in the gold mining industry to find optimal business plans for a mine.

Jan 1, 2003

By Lester G. Morrell

AGAIN in 1963, as in nearly every year since 1946, the Canadian mineral industry has established a new national record in value of mineral production. The 1963 estimated total value of $2,976 million is 5 percent higher than the 1962 value of $2,845 million.2 As in previous years, metals made up more than half the value of total production. For selected years since 1949 the category percentages and total value are as follows: [ ] Crude petroleum, Canada's most valuable mineral product, accounted for 21 percent of the total value of minerals in 1963. In descending order came nickel 12 percent, iron ore 10 percent, copper 10 percent, gold 5 percent, and uranium 5 percent. Asbestos accounted for 5 percent, sand and gravel 4 percent, and cement 4 percent. The complete list of Canada's mineral products includes more than 50 basic commodities.

Jan 1, 1964

By M. Ahrens, J. Gonser

Gearless mill drives are a well established solution for grinding applications in the minerals and mining industries. The paper describes the functionality and technical features of such drive systems as well as their advantages compared to other drive solutions. Due to the variable speed operation the grinding process can be optimized for ores with varying grinding properties. This leads to significant optimization potential for the plant design as well as for its operation. Furthermore, energy and cost savings due to optimized operation, high system efficiency and high system availability are shown.

Jan 1, 2007

By Caibin Wu, Bin Xie, Jiaqi Tong, Ningning Liao, Chong Zeng

Understanding the energy-size reduction relationship is vital to grinding process; therefore, this paper aims to show the energy-size reduction of magnetite-calcite binary mixture in a laboratory wet conical ball mill. Single magnetite, single calcite, and blended magnetite-calcite mixture at three weight ratios in four particle sizes were ground in a laboratory wet conical ball mill at four grinding time periods. The results showed that the particle size distribution of both fine particles and coarse particles of single and mixture ground product fitted well with the PSD computed by Rosin–Rammler-Benne function. The larger mass percentage of calcite is, the higher t10 of binary mixture ground product is. On the contrary, t10 in the mixture decreases as the percentage of magnetite in the mixture increases. The different breakage behaviors in blended samples are due to the hardness and particle size. The results of calculated ratio of energy absorption factor showed that the calcite consumed more energy in the breakage process of binary mixture than ground alone. The JK size-dependent breakage model based on the t10 method fits all the experiment data, be it generated from pure minerals, mixtures at different weight ratios, or each component separated from the mixture.

Jun 4, 2022

By Paul J. Ehret

With the passage of the Surface Mining Control and Reclamation Act (SMCRA), and the implementation of state permanent programs, underground coal mining operations are for the first time subject to government regulations regarding subsidence. These regulations now and in the future will directly affect the manner in which mining companies mine their coal. Since the promulgation of the original final regulations by OSM, numerous changes in those regulations have been made and many additional changes are pending in the near future. This paper will discuss state and federal approaches to regulating underground coal mines and examine issues surrounding future subsidence regulations.

Jan 1, 1986

By Lawrence J. Froisland

To aid in minimizing adverse environmental impacts of mining and mineral processing, the Bureau of Mines studied changes in soil characteristics in topsoil stockpiled during mining operations. Topsoil stockpiles in arid areas of New Mexico, Utah, and Wyoming were sampled over a 1- to 8-yr period to determine any changes in physical, chemical, or biological parameters in the top 15 ft of soil. Parameters examined in this study included soil moisture, pH, electrical conductivity, and cation exchange capacity; total nitrogen, organic carbon, carbon to nitrogen ratio, extractable potassium, and soluble phosphorus levels in the soil; general levels of bacteria activity in the soil; and productivity of the soil as measured by shoot yield in growth tests. Data were analyzed by multiple linear regression to determine possible effects of stockpile age and depth. Bacteria population counts, used as an indicator of goner l bacterial activity, was the only parameter found to be significantly correlated with stockpile age and depth at more than one site. Bacterial activity increased with depth at the two sites where it was measured. Activity increased with age at one site and decreased with age at the second. Significant changes in soil pH, electrical conductivity, and moisture were significantly correlated with stockpile age and depth at single sites. This study did not show significant, consistent deterioration in soil characteristics or growth yield of topsoil stored in stockpiles.

Jan 1, 1987

The estimation of the shear stress distribution around an excavation is important to the design of the excavation since shear stresses can generate cracks, loosen grain boundaries or otherwise degrade the mechanical and physical properties of the rock and lead to stability problems. In this study, the distribution of shear stresses in a pillar were back-calculated from the deformation measurements made from the SPDV (Site and Preliminary Design Validation) area at the Waste Isolation Pilot Plant (WIPP) site. A plausible pattern of shear stress around an excavation has been suggested based on the Zero Strain Boundary (ZSB) calculation, computer simulation using FLAC, and back-calculation using measured deformation rates in the pillars.

Jan 1, 1998

By S. S. Cole, C. E. Wood, T. L. Joseph

"INTRODUCTION Iron ore containing titanium was first used in blast furnaces over a century ago. It is well known that TiO2 is a slag-forming material that will increase the amount of slag produced by the usual gangue materials, silica and alumina. Increase in the volume of slag due to the presence of TiO2 and a lack of information concerning its effect on the properties of the slag have prevented the general use of titaniferous ore. Also rather com¬mon belief among furnace operators that the bottom of the furnace builds up when ores containing TiO2 are smelted has militated against the use of titaniferous ore. This building up of the hearth has been attributed to the formation of copper-colored crystals of titanium cyanonitride, which have been observed in the salamanders of blast furnaces. Until recently the availability of nontitaniferous iron ore has left little incentive to use ore containing titanium.The presence of vanadium in certain deposits of titaniferous magnetite in New York State has created new interest in problems connected with the use of titanium-bearing ore. It appears that most of the vanadium in this ore can be recovered in pig iron, which can be blown in a converter to produce a slag containing vanadium in amounts suitable for the production of ferrovanadium.The Titanium Division of the National Lead Co. recently erected a largo mill to treat ore from Sanford Hill, in Essex County, New York, about 50 miles west of Port Henry. The ore deposit was acquired from the MacIntyre Iron Co. and is often referred to as Sanford ore. It is one of the largest deposits of Iron-bearing material to be found east of the Lake Superior region and is being mined by open-pit methods."

Jan 1, 1943

By Pengfu Tan

Xstrata Copper at Mount Isa in Australia has operated one copper Isasmelt furnace and four P-S converters. The phenomena of foaming occur in above 10% of converter operations. A thermodynamic model of copper P-S converter and a viscosity model of converter slag have been developed to simulate the slag blow and copper blow. The model predicts the chemistry and viscosity of copper skims during copper blow. The effects of oxygen potential, charge of dirty materials, slag carry-over, under-blowing, over-blowing, and temperature on the foaming and viscosity of copper skims have been discussed. Some improvements of the industrial operations have been presented.

Jan 1, 2006

By E. D. Calvert

The objective of this research was to examine variations in melting and forging practice for four titanium-base alloys and to determine their effect on the resultant product. Of particular interest was the evaluation of the skull-casting technique. The data should serve as a guide to producers and consumers of titanium products. Physical properties of four titanium-base alloys in ingot form and in sheet form were evaluated and correlated, where possible, with variations in the melting and casting procedure. Consumable-electrode melting was used throughout, but arc current and furnace backfill pressure were varied, and ingots were formed both by melting directly into a water-cooled copper mold and by skull melting followed by pouring into a graphite mold. Alloying metal additions for the alloys tested were (1) 8 percent manganese, (2) 6 percent aluminum and 4 percent vanadium, (3) 6 percent molybdenum and 2 percent aluminum, and (4) 16 percent vanadium and 2.8 percent aluminum.

Jan 1, 1962