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By Rosengren KJ

Geotechnical conditions often have a critical influence on the design of new open pit and underground mines, but they are often considered of secondary importance in relation to other factors, such as detailed geology, orebody geometry and grade distribution. As a result, geotechnical studies may not be carried out during early project investigations or, at best, may be given only superficial attention, often to the overall detriment of the project. Technically and economically, it is logical that geotechnical studies should be integrated with geological investigations as soon as it becomes evident that the particular deposit may prove to be economic. The paper discusses the use of geotechnical information in the selection of mining methods and mine design for underground mines and for wall design and assessment of excavation characteristics in open pit mines. It then considers methods of obtaining the relevant data, with particular reference to exploration boreholes. Selected case studies on the application of geotechnical data to mine design are Included.

Jan 1, 1986

By Z. Manafi

Bioleaching of a copper sulfide ore containing "activated pyrite", using a mixed culture of mesophilic bacteria, was studied. This type of copper ore had been found unsuitable for flotation because it produces a concentrate containing relatively high iron concentrations and, therefore, a low copper grade. Microscopic observations showed that pyrite particles had been activated by the formation of a thin film of chalcocite. Hence, a bioleaching process was considered as an alternative to treat this ore. Following shake flask and acid consumption tests, column tests of the crushed ore (75% -12.5 mm) were initiated and the effects of culture medium, agglomeration, and irrigation type on copper recovery were studied. The results showed that all the columns containing bacteria had copper recoveries around 90% compared to the abiotic control column with a recovery of 50%. It was concluded that bioleaching could be successfully utilized to process copper ores containing activated pyrite.

Jan 1, 2007

By Greg Shapiro, Paul Dr. Worsey

Mining, quarry, and construction blasts are becoming more and more dependent on bench profiling. The use of accurate profiling gives the blaster better data for the most efficient blast results. So, we ask the question: What is the best method for measuring and analyzing burden?

Jan 1, 2019

By G. G. O. O. Uwadiale, M. A. U. Nwoke

The flotation of Azara barite tailings was investigated using crude rubber nut oil (RNOc), refined rubber nut oil (RNOR) and oleic acid as fatty acid collectors. Chemical characterization of the rubber nut oils indicated high acidity, high saponification values and high iodine indexes, which are indicative of a high fatty acid compositions. The Azara barite tailings analyzed 64.6% BaSO4 by atomic absorption spectrophotometry. Gravity and magnetic separation techniques yielded a BaSO4 concentrate with a grade of 74.8% and a recovery of 92.5%. Barium sulfate grades of 90.0%, 92.8% and 94.8% with recoveries of 80.3%, 85.4% and 86.7% were achieved with collector dosages of 750g/t crude rubber nut oils, refined rubber nut oils and oleic acid, respectively. Hence, rubber nut oils are effective fatty acid collectors for the flotation of barite tailings.

Jan 1, 1998

By G. B. Atkinson

Properties of catalysts prepared from intermetallic compound precursors were investigated by the Bureau of Mines as part of its mission to decrease U.S. dependence on foreign sources for scarce catalytic materials, such as nickel, cobalt, and chromium. Methods were developed whereby catalysts with surface areas of 30 to 40 m2/g were prepared from intermetallic compounds. Activity of these catalysts for the methanation reaction and methanol synthesis was deter-mined using a fixed-bed, single-pass, flow-through reactor. Catalysts prepared from rare-earth-nickel intermetallics had specific activity for methanation that was five times greater than that of commercial catalysts and were equal to or better than commercial catalysts with regard to sulfur tolerance. Under identical reaction conditions, catalysts prepared from thorium-copper intermetallics produced more than 10 times as much methanol as a commercial low-pressure catalyst and exhibited a high degree of catalytic stability.

Jan 1, 1982

By Martina Balic

Dynamic properties of the drilled shaft foundations supporting Doremus Avenue Bridge were determined by forced vibration testing. The main objectives of the substructure testing at Doremus Avenue Bridge were: (1) site evaluation with respect to the dynamic soil properties, and, (2) shaft evaluation for the purpose of definition of their dynamic stiffness. The site characterization entailed crosshole testing for the purpose of evaluation of the shear modulus profile. The drilled shaft impedance evaluation was done through forced excitation using an electromagnetic shaker. The responses of the tested shaft, as well as the response of adjacent shafts, were measured for the purpose of evaluation of the shaft interaction. To gain a better insight into the shaft dynamics, one of the shafts was instrumented with five triaxial geophones distributed along the full length of the shaft. The scope and results of the site characterization, shaft impedance and shaft interaction evaluation are presented.

Jan 1, 2004

By Matthew C. Pierson

Due to space limitations for transportation projects, many times sound walls must be constructed above mechanically stabilized earth (MSE) walls. These sound walls must resist lateral loads from wind or impact and must therefore be constructed on drilled shafts passing through the reinforced fill for the MSE Wall. Current design methods for the drilled shafts are believed to be overly conservative. Full scale lateral load testing of three foot diameter shafts contained within and solely supported by a 20 foot tall MSE block wall was conducted and the lateral capacity was evaluated. Shafts were tested individually and as a group. The data collected from full scale testing was then used to calibrate numerical models. This paper contains a discussion of how the facing type and stiffness affects the behavior of the numerical model as well as selected comparisons between the actual test data and selected model simulation results.

Jan 1, 2009

IT is not enough to know how to melt well and to have the bellows and charcoal for your purpose. If you wish to make small castings turn out well, on account of their thinness, it is necessary to aid the metals with unctuous and corrupting materials like tin, sublimate, arsenic, or realgar,

Jan 1, 1942

By R. H. Terhune

THE enormous production of pig-iron, together with the many difficult and interesting problems with which its manufacture is fraught, 11as secured to this industry the exclusive attention of scientists with reference to the chemistry of iron, while some of the minor departments of its metallurgy have suffered neglect. Particularly is

By D Stow, R Goodridge, K J. Molloy

A range of explosives has been specifically developed for soft ground blasting. These explosives can be used in both wet and dry blasting conditions, range in density from 0.3 - 1.2 g/cc and range in VoD from 2 - 4.5 km/s. This range of explosives has the potential to be tailored to ground type and is predicted to be suitable for a variety of applications which include: blasting in soft to medium overburden, coal blasting, wall control, and low vibration blasting. Trials have been conducted in several applications with encouraging results. Several cast/throw blasts have been conducted with these products partially replacing either ANFO or Heavy ANFO. The results from the blast have been equivalent in cast (per cent) and at reduced cost per unit volume. These products have also been used in presplit blasting and have again achieved equivalent or better results when compared to conventional presplit blasting at a lower cost per unit volume. This product has also been used in a vibration sensitive area replacing traditional explosive products, and generating excellent fragmentation and digging whilst maintaining vibration limits. This new range of products, NOVALITE, has shown great potential in many applications either reducing cost per unit volume, improving wall quality or improving productivity in environmentally sensitive areas.

Jan 1, 2001

The 76th Regular Meeting of The Rocky Mountain Coal Mining Institute convened at The Mark Conference Center, Lionshead Village, Vail, Colorado, and was in session at 9:30 a.m. A film-"Once Upon a Time" showing the stifling effect of unnecessary government regulations and the importance of protecting economic political freedoms was shown. Past President, Robert E. Murray, President, Western Division and Subsidiary Companies, The North American Coal Corporation, called the meeting to order. He introduced President Loren V. Linville, District Sales Manager, Industrial Products Division, Uniroyal, Inc. A biographical sketch follows: Loren V. Linville was born on December 29, 1925 on the family farm near Wiley, Colorado to Scott W. and Hazel Linville. He has one sister, a teacher in the public schools and a brother who is an optometrist in Gustine, California. Loren grew up in Lamar, Colo. graduating from Lamar High School in 1944 and spent the folllowing 2 years as a radioman in the US Navy. He graduated from Denver University in 1950 with a BS in Mechanical Engineering. On September 12, 1948 he married Norma. They have 3 children, Linelle, a teacher in New Mexico, Bruce an electronic technician in Colorado Springs and Kevin at home.

Jan 1, 1980

By John C. F. Randolph

Although China is believed to contain an enormous coal-area, but few memoranda have been published as to the character of its coals. Our belief as to the extent of its coal-fields rests mainly on the statements of travellers of all classes, religious, scientific, etc.,

Jan 1, 1887

By H. E. Powell

Over 5 million lb of chromium, 1 million lb of nickel, and 90,000 lb of molybdenum are lost annually in the dusts generated in the production of stain-less steel. Additional losses of these metals in the form of mill scale and grinding swarf may be double the dust losses. This Bureau of Mines report describes a process for recovering these and other metals in the form of an alloy steel suitable for recycling. Zinc and lead, when present in the wastes, are recovered as byproducts in the form of oxide fumes. The laboratory-scale process (10-to 25-lb charges) recovers up to 95 pct of the chromium, 100 pct of the nickel, and 100 pct of the iron. The resultant alloy contains from 10 to 20 pct chromium, 6 to 12 pct nickel, and 55 to 65 pct iron, with lesser amounts of molybdenum and manganese. The alloy is essentially free of zinc, lead, and sulfur. The zinc-lead fume obtained from the treatment contains about 40 pct zinc and 20 pct lead and represents essentially complete recovery of these metals.

Jan 1, 1975

By Michel Gamache

This paper describes a system that manages and assigns vehicles in real-time in an underground mine. Each dispatching decision takes into account the traffic on the road segments of the mine network, whether bi-directional or unidirectional, and ensures that each LHD (Load-Haul-Dump Vehicle) arrives in the right orientation at loading and dumping points. Such systems can be used for two main purposes: 1) as a strategic planning tool and 2) as a real-time managing and optimising system for operations. Using a simulator in conjunction with the fleet management system, it is possible to accurately estimate the impact on productivity of decisions such as the development of waiting areas (bays, sidings), or the addition (elimination) of vehicles to the fleet in operation. Moreover, when used in for real-time dispatching, routing and scheduling of vehicles, the system can optimise production with respect to various assignment criteria such as minimising the cycle time or minimising the deviation from an optimal production plan. Dispatching, routing, and scheduling are handled simultaneously, taking into account the mine status, operational constraints, and all available information.

May 1, 2001

ON p. 499 of the December issue Of MINING AND METAL-LURGY plans were announced for a memorial to en-gineers who died in overseas service during the World War and a gift to the University of Louvain on behalf of the engineers of America. In this connection it is proposed to erect a memorial tablet giving the names. of engineers who died in the foreign service. Members of the A. I. M. E. who gave their lives, so far as they are known, are listed below. It will be much appreciated if notice be given of any omissions and also if the name of some surviving relative be supplied in each case. Louis Baird, Lieut., Royal Field Artillery, British Army, killed on the battlefield, 1915. John H. Bellamy, Capt., Regimental Staff, 103rd Engi-neers, killed near Fismes, Aug. 9, 1918. Martin F. Bowles, Lieut., 1st Battalion, 355th Infantry, 89th Division, killed on the battlefield, Sept. 3, 1918. Andrew Burt, died in .active service, 1916. Stanley B. Carlisle, Machine Gun Battalion 346, 91st Divi- sion, died in France, Oct. 24, 1918.

Jan 1, 1928

Meeting of Mar. 26, 1915.-The following Committee on Nominations was appointed: Fred W. Bradley, Chairman; James F. Kemp, Past President; Frank M. Smith, Chairman Montana Section; R. C. Gemmell, Chairman Utah Section; Frank A. Ross, Chairman Columbia Section; Louis S. Cates, Arthur Thacher. The Committee on Precious and Base Metals and the Committee on . Coal and Coke were appointed, the personnel of which is shown in another part of this Bulletin. The President was authorized to appoint a Committee on Welfare with J. Parke Channing as Chairman. W. P. Cutter, Librarian of the United Engineering Societies' Library, was appointed a representative of the Institute on-the Committee oh Classification of Engineering Knowledge to co-operate with similar committees of other engineering societies. A vote of thanks was extended-to Edward B. Sturgis for his excellent work in arranging for the Annual Dinner. in February, of this year. The suns of $57.30 was appropriated to the New' York Section. It was resolved that in response to the courteous invitation from 36 members of the Institute in Arizona and the neighborhood, the 1916 summer meeting of the Institute be held in Arizona.

Jan 5, 1915

In this paper is given a general description of the Black Star copper orebody, its relation to the lead orebodies and the controlling factors in the mineralisation.Copper ore, in the form of chalcopyrite, was first noted at Mount Isa in 1930 during the surface drilling campaign to prove the downward continuation of the silver-Iead-zinc orebodies.Details of the occurrence are set out in table 1.Other sub-commercial widths were also disclosed and examination of these occurrences showed that commercial mineralisation could not be expected within 800 ft. of the surface. It was therefore decided that further exploration was not warranted until underground workings had advanced to this horizon.Detailed surface mapping showed two small outcrops of the host rock of the copper orebody. One occurrence, 50 ft. x 75 ft., was of quartz, with leaching suggesting former dolomite. Another outcrop, further north and west of silicified shale, with low grade oxidised copper, has recently been found. Both occurrences were above the hangingwall of the main copper orebody.When the workings in the silver-Iead-zinc orebody reached No. 7 level (875 ft. below the surface) further...

Jan 1, 1953

By J. Sjöblom

New copper and nickel processes, flash converting and DON, direct high-grade nickel matte smelting, have been developed in order to replace the conventional and not so environmentally friendly PS-converting process. With a laboratory scale laminar-flow furnace the combustion reactions of sulfidic feed particles can be investigated under simulated flash smelting conditions. In the present study, finely ground and screened feed fractions of a copper matte and a nickel matte were flash oxidized in a laminar-flow furnace. The experiments were carried out using 20, 21 vol% and 75 vol% O2 in nitrogen, at temperatures 1100 and 1300 °C and reaction zone length of 7.5-16 cm. The samples were quenched in a water film after a specified reaction time. The matte particle reactions were stopped after short residence time intervals in order to obtain a better understanding of the reaction mechanisms. Chemical analysis was used to determine oxidation degree, and optical and scanning electron microscope combined with energy dispersive analysis was used for characterization of the reacted particles. On the basis of the experimental results the reactivity of the mattes is discussed and possible reaction and dust formation mechanisms are considered.

Jan 1, 1999

By R. D. C. Shone

Consideration is given to the technical and economic feasibility of freeze desalination as a technique for the simultaneous provision of ice to cool deep mines and for the desalination of mine water. Freeze desalination has not been developed fully or commercially. For sea-water applications, it may not offer significant advantages over other methods of desalination but, for the unique mining application, a single dual purpose plant that produces desalinated ice could offer significant cost savings over combinations of separate desalinators and ice-makers. The current status 01 freeze desalination is reviewed, and the important aspects relating to mines are discussed. Some freezing processes that could be suitably modified are described. The possible use of conventional ice-making machines for desalinating mine water is also discussed.

Jan 1, 1987

By Gerard O'Brien, Douglas Comstock

"The construction of the Third Harbor Tunnel is the first major portion of the Central ArteryProject. The tunnel is designed to connect South Boston to East Boston to alleviateautomobile congestion through the downtown area. The 4000' long tunnel traversesBoston harbor as a cut and cover tunnel as opposed to a bored tunnel."

Jan 1, 1993