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By A J. Broome

Since 2003, there has been an unprecedented growth in the demand for engineering, technical and project services in the mineral industries. This demand for services became evident in Australia earlier than many other markets and has since spread globally. This growth has created significant issues for the strategic direction and planning by the service provider. Such strategic questions include:- how fast to grow, how to recruit, train and integrate new staff, what market sectors to service, the selection of targeted customer sectors and managing strategic growth with short term demands and commercial reality. These factors are discussed using in depth experiences and examples that illustrate these strategic approaches. The relevance of this new industry environment to New Zealand services will be highly discussed.

Jan 1, 2007

By W. F. McDermott

This paper covers the development, construction and operation of a 53-mile slurry pipeline operating in Tasmania, Australia. Special development techniques are discussed, as well as the operation of this line and its impact on transportation from remote areas.

Jan 1, 1970

By B Rouvray, R Bertuzzi

The development of a design-and-construct tunnelling project in Australia from its concept to its construction requires designs to be prepared and reviewed at several distinct stages prior to documenting ‘for construction’. On recent projects the post-tender stages have been variously called 30 per cent—70 per cent—100 per cent; or concept–substantial–final; or system definition–preliminary–critical. The design is reviewed at each stage by the designer’s internal reviewer, the contractor and its independent advisor(s), the owner and its independent advisor(s), the project’s independent certifier, proof engineers and often third-party stakeholders and their advisors. Documentation for each stage often dominates the design effort, at times distracting from design. This paper presents the authors’ experience of this design-and-review process. Comparisons of design budget and actual design spend and design program implications are presented. It is postulated that a subtle change has occurred in our industry that has diminished the value of the design dollar. Is there a better process? An alternative is suggested.CITATION:Bertuzzi, R and Rouvray, B, 2014. Reducing the cost of tunnel design in Australia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 501–506 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Luis Armando Espitia

AISI 410 martensitic stainless steel specimens were low temperature plasma nitrided at 400°C in a mixture of 75%N2:25%H2, during 20 h. Active screen technic was used to avoid any edge effect The nitrided case is composed of expanded martensite (a’N) and e-Fe3N iron nitride, whilst chromium nitride precipitation was avoided. Surface hardness reached 1275 HV0.01. The transverse microhardness profile shows a gentle hardness gradient with a NHT nitrided case depth of 28 µm. Nanoindentation tests were carried out in order to assess the hardness (H), the Young modulus (E), the H/E and H3/E2 ratios and the elastic recovery (We) of both nitrided and non-nitrided specimens. The cavitation erosion mass losses were measured as a function of exposure time. The results showed a decrease of 27 times of the mass loss compared to the non-nitride specimens. Wear rate decreased from 2.56 mg/h for the non-nitrided condition to 0.085 mg/h after nitriding. The increment in the elastic recovery and the higher hardness values are responsible for the greater cavitation erosion resistance exhibited by the expanded martensite. Such results showed that low temperature plasma nitriding and the formation of expanded martensite are effective to increase cavitation erosion resistance of AISI 410 stainless steel.

Jul 31, 2018

By R. V. Lundquist, A. E. Morris, E. L. Singleton

This experimental research was performed to determine rate - of - reaction constants on the MnO - C and Mn , C₂ - 3MnO systems at 1,100 ° , 1,150 ° , and 1,185 ° C. Reactions were conducted at atmospheric pressure under controlled flow of purified helium through the furnace chamber . The weight - loss method defined reduction percentages , and reaction products were identified by X- ray methods . The system Mn0 - C followed a linear reaction rate , and experimental results produced an apparent activation energy of 55.8 kcal per mole of Mn0 . The system Mn, C - 3Mn0 followed a parabolic rate of reaction law and yielded an apparent activation energy of 114.4 kcal per mole for the reaction .

Jan 1, 1964

By Eiichiro Mizushima

Catalyst systems comprising (Ph3P)AuCH3 and acid co-catalysts were found to be highly efficient for hydration of alkynes to give ketones. Methanol was the best choice of solvents. Introduction Hydration of carbon-carbon unsaturated bonds is one of the environmentally benign routes to the carbon-oxygen bond formation. Hydration of alkynes forming carbonyl compounds, an important variation in this category, is a well known reaction which has been extensively studied. The reaction by acid-catalysis is the most conventional method, while it is applicable only to electron rich acetylenes to obtain satisfactory yields (1,2). The hydration of simple alkynes usually requires another catalyst (co-catalyst), typically a mercury(II) salt (3), which is inconsistent with the guiding principle of Green Chemistry (4).

Oct 1, 2003

ABSTRACT Understanding process histories and worker exposures in nickel production operations is critical in determining the role nickel compounds play in respiratory cancer incidence. As part of a series on Vale Canada’s (previously known as Inco) nickel processing operations, this paper includes descriptions of Ni electrolytic operations at refineries in Port Colborne, Ontario (1922–1984), and Thompson, Manitoba (1961–present). Industrial hygiene measurements, by area and personal sampling, of workplace aerosols at these operations are reported.

Jan 1, 2014

By C. Burton Clark, J. Spotts McDowell

Refractories are defined as "materials having the ability to retain their physical shapes and chemical identities when subjected to high temperatures," or as "nonmetallic materials suitable for the construction or lining of furnaces operated at high temperatures." While resistance to "high" temperatures is thus the primary requirement for refractory materials, it is by no means the sole requirement. They must be able to withstand thermal shock resulting from rapid heating or cooling; other stresses induced by temperature change; pressures from the weights of furnace parts or contents; mechanical wear (abrasion) resulting from movement of furnace contents; and chemical attack by heated solids, liquids, or gases. Refractories of many kinds are needed for the many and widely diversified industrial applications. Those in greatest demand are classified on the basis of composition or properties into a few main groups, known as alumina-silica, silica, basic and insulating refractories. In each of these groups there are several classes. In addition to those included in the main groups, there are various special refractories, including silicon carbide, carbon, zircon, zirconia, alumina, and several others. Alumina-silica refractories comprise two main divisions: fire clay and high-alumina. The alumina content of fire-clay refractories covers the range from about 45 pct to 18 pct, and the silica content from 50 pct to 80 pct. The alumina content of fired high-alumina refractories ranges from about 99 pct to 45 pct, and the silica content from about 0.5 pct to 50 pct. Silica refractories of the different classes contain 94 pct to 97 pct silica. Basic refractories include periclase (magnesite), chrome spinel, forsterite, and dolomite. Refractory materials, including insulating firebrick, are supplied mainly as preformed shapes. Other products include bonding mortars and high temperature cements, ramming mixtures, plastic firebrick, hydraulic setting castables, dead-burned grain magnesite, and dead-burned dolomite. Refractory brick are classified on the basis of their physical form as Standard Sizes and Special Shapes. The Standard Sizes are brick of certain definite sizes and relatively simple design which are used in sufficient amounts to permit quantity production. The brick most widely used are the standard 9 in. X 4 ½ in. X 2 ½in. and 9 in. X 4½in. X 3 in. straights and corresponding series of sizes. All brick of nonstandard dimensions are regarded as "special shapes." They include a wide variety of brick regularly used for specific services, such as baffle tile for boilers, checker brick for regenerators, and others; together with shapes of special design manufactured on particular orders from designs submitted by the user. Not included in the broad classifications of Standard Sizes and Special Shapes are several specific-service refractory products, usually made by companies which specialize in their manufacture, or in some cases by the consumers themselves. These products include

Jan 1, 1960

By C. W. Owings, L. D. Tracy

"IntroductionMany bituminous coal-mining companies have inaugurated extensive safety Programs, but the failure to have approved or permissible equipment or safe practice in only one part of a mine has resulted in disaster. The necessity of using only equipment bearing the U. S. Bureau of Mines approval plate is emphasized by the fact that many accidents are the direct result of carelessness on the part of trusted employees using non-permissible equipment. A concrete example is found in the case of an explosion on October 26, 1926, in a mine in the Pittsburgh district, Pennsylvania.Story of the ExplosionAt about 10 o'clock on the night of the explosion an examination was made in No 2 butt left and parallel off 7o. 14 north, and was found to be clear of dangerous accumulations of gas. (See figure). Several hours later a crew of two men brought a self-propelling rock-dusting machine within 50 feet of the face of Po. 2 butt parallel before they examined for gas. The machine operator found an accumulation of explosive gas about 18 inches from the roof. He began to wave his arms thoroughly mixing the gas and air. Undoubtedly a highly explosive mixture was created, and as the men attempted to run the machine back to fresh air an explosion occurred.The helper dropped to the floor and was burned about the face and wrists. The machine operator ran down the entry and was more severely burned about the face, neck, and arms. He later developed pneumonia and died. Both men reached the door in the chute between No. 14 and No. 15 north. A pumper, who had felt the rush of air, found the men and helped them to walk outside."

May 1, 1927

By J. A. Organiscak

In the United States, respirable coal mine dust exposures are limited to a 2 mg/m3 time weighted average for a working shift. If the silica content of the sample exceeds 5 percent, the 2 mg/m3 standard is reduced according to 10- (% silica) to limit silica dust exposures to 100 µg/m3. Examinations of dust sampling data collected by the federal coal mine inspectorate showed that roof bolter occupations continue to be at risk for overexposure to respirable silica dust. Testing at the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health assessed the effectiveness of a canopy air curtain for controlling occupational exposures to respirable silica and coal dusts. Initial testing found that zones of higher velocity airflow shrank as distance beneath the canopy increased. This suggested that protection from occupational dust exposures would likely decrease as distance beneath the canopy increased. Further testing revealed that coal dust reduction efficiencies were most affected by changes in interference air velocity and, to a lesser extent, changes in canopy air quantity. However, respirable silica dust percentages under the canopy were not affected by such changes and, in fact, were not significantly different from silica percentages measured outside the canopy. This implied that the air curtain was equally effective on both respirable coal and respirable silica dust particles.

By Robert W. Bartlett

Biooxidation of an ore heap containing only a few percent of sulfide minerals requires insertion of a very large amount of oxygen either by natural air convection, forced air ventilation or gaseous diffusion. While shallow heaps, those with lateral distances much greater than their height, are of great interest for many heaped ore processing operations, natural convection is often ineffective for oxidizing them because of inadequate lateral flow into the heap's interior. Oxygen can diffuse into a shallow heap from its upper, horizontal surface in contact with air. Oxygen diffuses through the air-filled void space within the heap, driven by the oxygen concentration gradient resulting from internal oxygen depletion caused by mineral oxidation. Oxygen diffusion, coupled with the chemical reaction kinetics oxidizing the sulfide minerals, is analyzed for conditions of rapid mineral oxidation kinetics, requiring small mineral grain sizes, and for typical ore heap biooxidation parameters. Practical limits on heap heights are presented for effective biooxidation of the sulfide minerals within times of interest for heap biooxidation of refractory sulfide gold ores, one to three years.

Jan 1, 1995

By Holcombe R. J, Dobos S. K, Little T. R

Blue amphibole-bearing rocks in the North D'aguilar Block of southeast Queensland occur either as relict pods and lenses within regionally extensive greenschist facies phyllites and schists or as blocks entrained in serpentinite-matrix melange. Epidote + crossite-bearing varieties predominate and formed under conditions consistent with underplating and high P:T metamorphism in a subduction-related tectonic environment. Neither lawsonite nor jadeite has been observed and metamorphic conditions are estimated at 380-4500C for pressures of 0.5-0.8 GPa. High P:T metamorphism occurred during the earliest stages of deformation and was superimposed upon protoliths of inferred Late Devonian - Early Carboniferous age, including mafic volcanics, tuffs and coarse volcaniclastic breccias as well as pelagic and henipelagic sediments, all of which have undergone varying degrees of over-printing to the greenschist facies. Greenschist facies metamorphism occurred during the second phase of deformation and was associated with the formation of mainly flat-lying or subhorizontal structures; it followed the cessation of subduction and occurred in response to either thermal relaxation during uplift or the imposition of regional heating induced by crustal thickening and/or synkinanatic granite emplacement. Uplift and cooling of the high P:T rocks was completed by 260-265 Ma and may have occurred in response to the same extensional processes which gave rise to the onset of rifting in the adjacent Esk Trough.

Jan 1, 1990

By L. J. Gerber, O. D. Eniowo, L. D. Meyer, S. R. Kilambo

Artisanal and small-scale mining (ASM) operations continue to grow across sub-Saharan Africa and serve as a source of livelihood to many rural communities. Owing to safety, health, environmental, and social concerns, the occupation has been regarded as a menace in several sub-Sahara African countries. Recent studies in the field of ASM prescribe formalization as a way to tame its excesses while enhancing its potential. This paper explores the concept of formalization as it relates to ASM and how it is being affected by the funding situation. The paper seeks to address the question as to whether formalization of artisanal mining operations can achieve the desired results in view of the lingering credit constraints in this mining subsector. It is recommended that, as a way of extending the scope of formalization, focus should be placed not only on access to credit in ASM but also towards optimizing the creditworthiness of ASM firms, with the goal of improving the viability of the operations.

Mar 2, 2022

In redesigning the cyanide plant at Mount Torrens, in conjunction with Mr. L. W. Grayson, the manager, several minor alterations were introduced in order to have the operations under thorough control, and these having proved serviceable may be of sufficient interest to merit a description here. The lixiviation vats, though only 8 feet in diameter, were retained, but the pipes leading away from the bottom were reduced from two inches to half-an-inch in diameter, and had a fall to the zinc boxes of about 4 feet. As these small pipes were completely filled by the solutions fiowing away from the vats, they exerted a suction equal to their fall and thus hastened the rate of flow, so that tailings containing a larger proportion of slimes could be treated than was possible where the larger pipes were used, as, there not being sufficient fiow of solution to keep the latter filled, no suction could be obtained with them. It was found that with'most of the tailings treated a sufficient flow could be obtained from the half-inch pipes when the taps on, them were only one-third to half open. The lower end of each of these pipes was connected by means on indiarubber tubing with the sille hole of 11 in aspirator bottle, and to the mouth of this bottle a few feet of similar tubing was connected, so that the solutions coming through could be directed into either of the fixed tubes leading respectively to the waste water tank the strong solution zinc boxes or the weak solution zinc boxes.In working the vats, the following method was found to give good results. While filling the vats with tailings the taps were left open, so that the water might drain off into the waste water tank the surface of the tailings was carefully levelled. When the strong solution was run in at the top, the air contained in the interstices of the tailings was forced through the half-inch pipe at the bottom as a strong blast, instead of, as I believe js usual, escaping by means of channels formed by it through the tailings, and thus tending, it would appeal, to render the disposition of the tailings less even and to make.

By J. P. Coughlin

The U.S. Bureau of Mines has developed a monitoring system that acquires and analyzes data for use in determining the conditions that may precede mountain bumps in coal mines. Based on a UNIX workstation linked to an array of geophones in a working longwall operation, the system captures complete waveforms of microseismic events and simultaneously obtains continuous samples of the voltage levels of each geophone. Event rates and locations are calculated and displayed in real time on the UNIX workstation, which is situated in an underground instrumentation room. These results also are transmitted from the workstation to a display computer near the longwall face. The system runs continuously and has the capability to acquire, analyze, display, and archive microseismic (transient) data and single point data, such as closure and pressure changes, simultaneously.

Jan 1, 1993

By Agbo Chima

Low-lying sections of open-pit mines accumulate water, especially during the rainy seasons, preventing access to resource-bearing areas. To sustain mining operations, the water must be lifted out of the flooded pits at a high flow rate using pumps. These pumps need to be mobile so that they can be removed during drill-and-blast operations. Most mobile pumps rely on diesel engines with high maintenance requirements. A special pump design was developed to address the unique needs of open-pit mining while making the dewatering process more sustainable. Using the target flow rate and head data, an efficient pump was designed, encased, and deployed in the open pit. A variable speed drive (VSD) was installed in a protective skid so that the pump could be tuned to match the preferred flow rate at any point during its operation. This system was tied to the national electrical grid instead of being powered by diesel pumps, which reduced the carbon intensity per kilowatt-hour. The high availability, low maintenance requirement, and greater reliability reduced the use of spare parts, the fuel consumption, and the logistics associated with operating the pump. This further reduced the carbon footprint of the dewatering process. This paper provides some of the two-year performance metrics for a deployment in West Africa. With a focus on availability, maintenance costs, average cost per volume lifted, and carbon footprint, this encased pump system is compared to the diesel-driven pumps that it aims to replace.

Jan 1, 2023

By J-P Strydom, J P. Z, S. Schafrik, M. Beck, Z. Agioutantis

Developing a method to accurately determine the weight and distribution of the load within a shuttle car bed eliminates the need for manual activation of the flight chain. Accordingly, this experimental study characterized the thermo-mechanical response of two unique load cells in force shunt, implemented as an engineering control to quantify load position and distribution without human intervention. The influence of environmental and installation conditions on the measurement accuracy was quantified and determined to be indirectly dependent on the characteristics of the material load cells that are mounted to.

Feb 22, 2026

By Raymond M. Stateham

Calculations based on data obtained from measurements of smoke from coal-fired powerplants predict that infrared imagers will be useful tools for smoke vision. Infrared imagers operating in the 3-to 5-um spectral region have been evaluated for this purpose. A mine opening 110 meters long was filled with smoke from burning coal, and two men, wearing breathing apparatuses, moved through the smoke to serve as targets. The men were detected and identified at 80 meters.

Jan 1, 1976

By W. R. Ingalls

THE main objective of everybody, individually and collectively as the people of nations, is to earn their living and improve the scale thereof as much and as rapidly as possible. We are able to earn" our living only by working and producing. We I are able to rise to higher standards of comfort only by increasing our production of goods, or diminishing the waste of those that we do produce, or both. This statement is trite. It is equally trite to dwell upon the importance of increased production to be derived from increased efficiency of labor and improved manage-ment; and the good results that would accrue to every-body if employers and employees would work together to secure the maximum of production at the minimum of cost. All of this is nothing more than platitude, to which every intelligent person subscribes in the abstract; but what concerns us especially, and what is neither so easy nor so understandable, is to translate the expres-sion of the abstract principle into formulas for action. The national net income obviously may be increased in two ways, or by both together. One is to diminish the waste of the goods that we already have made available. The other is to increase the supply of goods. .Increasing the supply of goods may involve the elimina-tion of waste, but a distinction is to be drawn between the waste of things that we have and the failure to obtain those that we might have. If we limit the term "waste" to the careless and profligate use of the materials that have come into our possession, together with the absorption of labor in doing obviously unnecessary things; and if we character-ize by the term "inefficiency" the failure to accomplish in our industrial operations the best of which we are capable, we shall create a distinction that will be pro-motive of clear thinking. In this paper I am going to deal with inefficiency, not waste, observing the distinc-tion, arbitrary if you please, that I have made. Without any doubt the greatest inefficiency that exists in our economic affairs is that which causes hundreds of thousands, perhaps millions, of men to be idle a good deal of the time. The major reasons for such idleness are two-fold. One of them is the conse-quence of what for convenience may be called business cycles, although I do not hold to the hypothesis of business cycles as it is now being rather widely expounded. That hypothesis involves the idea of rhyth-mic undulations due to causes unknown, but which it is hoped may be ascertained. The movement of busi-ness in waves up and down is undeniable, but that there are recurrences of cycles every so often is purely imag-inary, I think. It is unnecessary-to digress into that subject. The extents of the rises and falls above and below a median line undoubtedly is less than is commonly supposed.

Jan 3, 1922

By Clarence Hall, CHARLES F. MUNROE

Of the common causes of the larger mine accidents, such as falls of roof and coal, gas and dust explosions, mine fires, and the misuse of explosives, all of which are often closely related, each must be studied and fought in a manner peculiar to itself. The last mentioned, the misuse of black powder and other explosives, is sometimes considered the least important of these causes of mine accidents; but its impor- tance is much greater than the statistics indicate, for the reason that the misuse of explosives is the true cause of many of the fatal mine fires, gas or dust explosions, and falls of roof that are credited to other causes. Both the quantity of explosives used and the number of purposes to which they are applied are increasing. They are now made at about 150 plants, in different parts of the United States, and the product of a single year is estimated at nearly 500,000,000 pounds. Nothing in all this material is a safe or "safety" explosive when in the hands of a careless or ignorant person; and this is true whether considered in connection with the shipment or the use of these explosives. In addition to the large losses of life and property resulting from an improper use of explosives in mining, the recent statistics of the railway bureau for the safe transportation of explo- sives have shown more than 400 persons killed or injured and over $3,000,000 worth of property destroyed by explosives in transit by rail. The fact that three years of cooperative effort under the wise supervision of this bureau has reduced these losses to almost nothing encourages the hope that similar cooperative effort may likewise greatly lessen losses of life and property from the use of explosives in mining. The additions to the large death roll of our mines make a recurring appeal to the public for fair treatment of the coal-mining industry, and to the miner and the manager that they join in every possible effort for greater safety. It may never be possible under conditions such as exist to-day to prevent mine accidents entirely. Little can be accomplished in that direction by either the operators or the miners working alone, but experience in all countries shows that

Jan 1, 1911