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By Duk-Won Park

A new gage for monitoring fractures in underground openings was successfully developed utilizing the reflection photo-elastic technique. The gage may be used to detect crack initiation in mine openings or tunnels so that remedial action may be taken to prevent further deterioration. Fringes concentrated around the cracks were spread by the use of rubber backing. Crack growth as little as 0.003 inch up to as much as 0.1 inch width were detected in this study. Variation of gage materials will provide alternative ranges. The feasibility of the method was tested and calibration was made in the laboratory study. Field study successfully demonstrated the capability of applications in detecting mine roof crack development.

Jan 1, 1982

By Kan Aketa

The Japanese iron and steel industry has been developed remarkably, supported by the increase of steel demand. In particular, progress in various technical aspects of the ironmaking process, including burden materials, equipment, and operation has greatly contributed to the increase in productivity and the reduction of the fuel rate in blast furnaces. With the recent rise in the price of petroleum, the conversion of the energy source from oil to coke has resulted in a temporary increase in the fuel rate of blast furnaces.

Jan 1, 1982

By R. F. Hadley

Alluvial valley floors constitute a valuable land resource and have been important to ranching operations in semiarid western United States. This resource may be in jeopardy locally if the alluvial deposits are disturbed by surface mining of coal deposits. Erosion problems caused by poor land-use practices can cause trenching of the unconsolidated alluvium with a consequent lowering of the water table and depletion of soil moisture needed to support vegetation. Historical evidence of this sequence of events is abundant in geologic literature and serves as the basis for assessing potential impacts of surface mining. The potential geomorphic impacts of surface mining on alluvial valley floors with regard to fluvial processes are: (1) disruption of the longitudinal profile followed by valley trenching and high sediment yields downstream and (2) replacement of the excavated alluvium with unconsolidated material that does not have similar physical characteristics and may be susceptible to erosion. Mining may disrupt the existing hydrologic framework affecting streamflow, ground-water levels and water quality of both surface water and ground water. Although functional hydrologic and geomorphic processes are similar, each valley represents a complex environment that does not submit to broad generalizations.

Jan 1, 1978

The 25th Peruvian Mining Convention (Convención de Ingeneieros de-Minas del Perú) was held Sept. 10-14, 2001, in Arequipa, Peru. The biennual meeting, sponsored by the Peruvian Institute of Mining Engineers (Instituto de Ingeneiros de Minas del Peru), is designed to showcase the Peruvian mining industry and to ?promote progress in the national mining sector.? The convention consisted of technical sessions, forums, field trips and social activities. The technical sessions featured 80 papers selected from more than 200 papers submitted. The well-organized 2001 meeting was held at the Tecsup Institute of Technology of Arequipa. The meeting was held in conjunction with Exposición Technologica Minera (Extemin), a mining trade exhibition. The2001 Extemin had representatives from more than 400 companies in attendance. In addition to the many Peruvian companies present, the trade exhibition featured pavilions representing the United States, Canada, Germany, Australia and Chile. Registration at the 2001 meeting was about 3,300, a conference record. The theme for the 2001 meeting was Mining: Society and Development. Mario Brescia was chairman of the organizing committee. He said in his opening remarks that ?this year?s meeting seeks to emphasize the commitment on the part of the [mining] companies to treat our natural resources responsibly, controlling any adverse impacts and giving priority to group benefits.? Consistent with this theme, many of the technical papers stressed environmental and social responsibility. Many successful examples of environ-mental and social responsibility on the part of the mining industry were presented in the technical sessions.

Jan 1, 2001

By Joseph Sopko, Xavier Lacourse-Dontigny

For the REM (Réseau Express Métropolitain) project, a 2500 m tunnel was built using a tunnel boring machine (TBM) under the Montreal Pierre Elliott Trudeau Airport (ADM). Although the geology under the Montreal Airport (ADM) would have been suitable for an excavation with a hard rock machine, the rst section reuired an earth pressure balance (EPB) TBM due to the soft soil located under wetlands. After excavating 280 m, the TBM was blocked in a transition zone of unconsolidated, water-bearing soils directly above the underlying bedrock. A free air intervention was not possible due to these geological conditions. After several failed attempts to create a slurry cake for hyperbaric interventions, a ground freezing system was designed and implemented, incorporating angled pipes drilled from outside the wetlands to directly in front of the cutterhead. This paper discusses the engineering reuired to form a frozen, water-tight zone in front of the cutterhead using liuid nitrogen. It also describes the complex method of replacing the disc cutters while holding the ground freezing system active in a manner protecting the health and safety of the workers.

Jun 23, 2024

By Hans E. Tausig

The economics of transporting minerals by sea in less than full cargo lots encompasses an analysis of production costs, sale and inventory calculations and a careful comparison of ocean freight costs all of which when pieced together will usually definitively indicate which of the ocean freight alternatives is the correct one for the economic factors involved. To illustrate: Let us assume that a production to be marketed yields 60,000 metric tons of copper concentrates over a twelve month period. Shipment is geographically viable through Vancouver, B.C. The production has been sold to a Japanese Smelter and the mine produces at a rate of 5,000 metric tons of concentrates per month. The copper has been sold CIF FO. The Seller has carefully investigated ocean freight rates Vancouver, B.C./Hibi, Japan and finds that he could obtain a twelve month freight contract at $15.00 per metric ton FIGS based on a loading/discharging speed of 4000/ 2000 metric tons per WWDSHEX (weather working day, Sundays and Holidays excluded) this freight rate being predicated on shipping in lots of minimum. 15,000 tons. A further freight investigation reveals that to ship at the same terms and conditions but in lots of 5,000 tons, and shipping each month (in accordance with the mine's actual production) would cost $20.00 per metric ton FIOS. The calculation that is now made is whether it is more desireable to pay a higher ocean freight by shipping in 5,000 ton lots or to pay the lower freight where here the ocean freight involves a difference of some $300,000.00.

Jan 1, 1979

By C. D. Buttgereit

A variety of mathematical techniques are available in the pertinent literature concerning the interpretation and reduction of aeromagnetic data. The quantitative methods applicable to this data en¬compass a wide spectrum including filtering, continuation, derivatives, reduction to the poles, spectral analysis, and "undraping" of flight line data. With the aid of the digital computer, the techniques listed, and others, can be computationally performed on a gridded data set. In addition, current sophisticated computer hardware permits the systems analyst greater latitude in the storage and retrieval of data and in the display of resultant naps on a digital x-y plotter than previously available. Although many interpretive techniques concerning magnetic data have been published and computer machinery has been on the market, little has been written incorporating both disciplines into a unified digital processing system. In the present paper, a general purpose system in given which in designed for routine use in the interpretation of aeromagnetic (and other potential field, etc.) maps.

Jan 1, 1970

By Jue Kou, Fazhao Sun, Jiang Liu, Cuili Gui, Baoqiang Yu, Chunbao Sun

A novel special magnetic separator was developed based on the special properties of precious metal-bearing alloy in highgrade nickel matte. The recovery of Au, Pt, and Pd was 77.79%, 84.79%, and 81.79% respectively at optimum operation conditions of magnetic separator feed of 2.5t/h, pulp density of 45%, and flush water of 1.5t/h, and the recovery significantly improved comparing with normal magnetic separator. Magnetic field simulation of the special magnetic separator indicates that magnetic intensity of 0.6 T can be generated on the surface of magnetic drum, which can strengthen the recovery of heavy alloy that contains precious metals. The alternate strong and weak magnetic field can also make magnetic particles rolling on the surface of drum, which will reduce the generation of magnetic agglomeration to a large extent and decrease the content of impurities in magnetic concentrate.

Jun 16, 2022

By Alcides Freitas

The great importance of aggregates as a basic building and maintenance material for both public and private projects makes the identification and availability of this valuable resource imperative for our economic and social well being. This was one of the main reasons that led the California Legislature to enact the Surface Mining and Reclamation Act of 1975 (SMARA). The Act requires the State Geologist to classify mineral areas in the state and the State Mining and Geology Board to designate mineral deposits of regional or statewide significance. What is the "Classification and Designation" process and how is it working?

Jan 1, 1984

By E. R. DeMen

In late 1965 General Mills announced the availability of a new liquid ion exchange reagent, LIX®-64, for the recovery of copper from various solutions, such as dump leach liquors. Acceptance of this material by the copper industry has been gratifying. A number of pilot plants have been operated, and at this writing there are four commercial plants either in operation or under construction. The properties and operating characteristics of this reagent have been described in previous papers.1,2 LIX-64 is quite effective and selective for copper extractions although partially limited in pH ranges, losing extraction efficiency as the acidity of the feed solution increases to below pH 1.0. Also, the LIX-64 content in the kerosine carrier was limited to about 10 volume percent (except for special cases) because of rapidly decreasing phase disengagement rates above this content. This in turn led to large plant capital costs, as the organic flow rates had to be in- creased (rather than LIX-64 content) to extract the copper from high content liquors. This was true in all circuits where the feed copper content ran above 2.0 g/l copper. A reagent was needed which would extract copper from more acidic liquors (or higher copper content liquors) and which exhibited improved phase disengagement characteristics with reagent contents up to 30 volume percent. General Mills is pleased to announce the availability in commercial quantities of a new and improved reagent, L+-64~. This reagent broadens the pH range in which copper can be extracted, and exhibits superior phase disengagement characteristics. The improvement in the reagent has been noted in laboratory circuits, as well as pilot plant runs and commercial operations.

Jan 1, 1970

By R. R. Klimpel

This paper demonstrates, using the results of an unusually complete industrial test sequence, what the various interactions are between grind size, collector dosage, and frother type. While particle size is universally acknowledged to be important in optimizing industrial copper sulfide rougher flotation circuits, many of the various interactions that do occur at the industrial level with particle size are still being identified and/or quantified. This study also presents, in a consistent manner, the changes in flotation kinetics that occur as a function of particle size, in a typical industrial circuit along with some insights as to how flotation operators can optimize rougher circuit performance.

Jan 1, 1993

By K. L. Ludeke

For many reasons it appears that deep-rooted, perennial shrubs offer potential for improved stabilization and provide maintenance-free vegetative cover to harsh sites where perennial grasses have not been successful. The very fact that a drought-adapted shrub has a massive root system that can use moisture from a greater volume of mineral waste soil materials suggests that long-range arid environment resource development may be greatly enhanced by utilization of desirable forage shrubs. An effort is underway to assemble information and plant materials of promising species from many arid regions of the world. Surprisingly, many of the better plants for arid sites are quite high in protein content, and with proper management, breeding, and selection may prove to be very desirable livestock feed. Advancements in arid-land solid waste stabilization hold favorable promise for many industries that mine and mill in arid regions for effective reclamation of disturbed areas. Particularly exciting is the possibility of establishment of high density maintenance-free vegetative cover of climax vegetation that reclaims the disturbed area back to its original land use. Because of high shrub productivity, stabilization potential, nutritional quality, and reclamation success, greater use should be made of shrubs in disturbed land reclamation associated with mining and milling operations in harsh arid environments.

Jan 1, 1984

By Edward C. Heistermann

The Falkirk Mining Company, a wholly owned subsidiary of The North American Coal Corporation, is located 80 kilometers (50 miles) north of Bismarck, North Dakota. Falkirk is under contract to provide 5.08 mil- lion tonnes (5.6 million short tons) annually to the Coal Creek Generating Station, an 1100 mega- watt electric plant owned by the Cooperative and United Power Associations of Minnesota. Coal Creek is located 2.4 kilometers (1 ½ miles) south of the Mine. Electricity from the plant is transmitted to rural electric customers in Minnesota via a 400-kilovolt D.C. power line.

Jan 1, 1982

By Jens Classen, Martino Gatti

"GENERAL PROJECT DATAThe Sparvo Tunnel is part of the “Variante di Valico” project, a new 65km (40mi) highway link between Bologna and Florence, designed to renew the existing A1 route which connects Bologna and Florence. It is composed of 2 x 2,5km (1,55mi) twin tunnels excavated inside a complex geological context, characterized by the presence of a series of surface landslides and methane gas.The inclination is 2,6 % and the minimum radius is 1.400m (4.600ft). The two tunnel tubes were excavated by a 15,6m (51ft) diameter EPB-TBM from summer 2011 to summer 2013. The internal diameter of the concrete lining is 13,6m (44,5ft), made up of precast concrete segments 2m (6,5ft) long and 70cm (28”) thick, being the largest and heaviest segments ever produced. Excavation went smooth apart from initial problems concerning clogging problems and a main bearing damage of the TBM, which are discussed in a further paper during the congress. No structural damage was observed until the end of the TBM drives.SITE OBSERVATIONS DURING THE POST-EXCAVATION PHASEThe first evidence of the stress state of the segmental lining appeared on November 20, 2013 inside the northern tube (1st drive). Ring No. 884 showed obvious signs of overstress, resulting in spalling and crushing of the concrete, and the subsequent bending of the reinforcement, as visible in figure 1.At this time the tunnel invert was already partially backfilled, and construction traffic was running through the tunnel. First safety measures included closing of the tunnel, and initial measurements of the displacements."

Jan 1, 2016

By W. L. Dare

Land use planning is not a new concept in the United States but the emphasis has changed drastically since the early 1960's. Under the old interpretation we tried to expand our frontiers and develop our land, but as society has become more affluent and mobile the demand has grown to preserve those parts remaining undeveloped. There is something of a paradox inherent in this change of emphasis. While affluence has motivated our support to preserve the quality of the natural environment, industrial development is needed to support the affluence. Because we cannot accomplish all of each, sound planning and compromise will be necessary since it is unlikely that, the American people will want to surrender much of their life-style or their awakening environmental concern. Any industrial society, whether a goal reached or an aim yet ahead, is built largely on the use of mineral raw materials and energy, the physical base of nearly all activities and products. The standard of living which is important to us all is growing more dependent upon these minerals, metals, and energy fuels. Although reduction in consumption of raw materials may be acceptable to those at a certain economic level of a society, those who have not reached that level cannot be expected to accept a lowering of their present or anticipated standard of living.

Jan 1, 1974

By G. K. Derby

Paper presents project results investigating current techniques for dragline wire rope removal and the development of less hazardous means of performing the task. The cannon is the most prevalent method used in American surface mines. A cannon test program was conducted that used 40-and 50-grain primer cord to establish force produced using a 56-pound projectile. Socketlwedges were separated to establish separation force data. Two alternative removal methods, pendulum ram and portable hydraulic pusher, were developed and tested. Both provide sufficient force to effect separations under normal conditions on draglines with up to 78- cubic yard buckets.

Jan 1, 1984

By E. A. Wieselmann

In 1970 Texasgulf (Australia) introduced natural gamma radiation logging of drill holes for exploration in the Hamersley Iron Province of Western Australia. Drill hole logs have allowed positive stratigraphic and structural correlations within complexly folded secondary hematite ore deposits and between individual iron ore deposits separated by distances in excess of seventy-five miles. A Neltronics model KPD logging system and gamma-ray sonde are being used to measure the natural gamma radiation of the enriched Brockman and Marra Mamba banded iron formations. The parent banded iron formations are composed of thick, chemically precipitated iron oxide, chert, iron silicate, and carbonate with thin intro-formational clastic horizons. These clastic horizons give a greater natural gamma radiation than the banded iron horizon, and each clastic horizon has a characteristic radiation profile related to its composition and thickness. Because the natural gamma-radiation profile is unchanged during secondary enrichment of the iron formation, the present stratigraphic position of each drill hole can be established and complex folding can be accurately traced in the sub-surface. Gamma ray logging of percussion drill holes has made feasible a significant reduction in diamond core drilling without loss of accuracy. At the same time, it has provided a means of rapid evaluation of complexly folded iron ore deposits.

Jan 1, 1975

By Raymond A. Bradbury

A significant news item appearing in a coal mining journal in November 1969 stated simply that a Caterpillar D-333-CNA engine had received Bureau of Mines Schedule 31 approval. This item occurring at the time a new mining property in Martin County of East Kentucky was being prospected and prepared for mining, resulted in the manage-ment of Martin County Coal Corporation asking the question, "Why not use diesel equipment in our new operation?" Martin County Coal Corporation is part of the A. T. Massey Coal Company, Incorporated organization. The property being developed is on a 17,500 acre leasehold obtained from Pocahontas Land Corporation and lies in the Wolf Creek area of Martin County. The Norfolk and Western Railway Company built a 24-mile railroad into this undeveloped section of Kentucky to tap a huge reserve of steam coal. Duke Power Company is the customer who will take all of the production from Martin County Coal Corporation mines which ultimately is projected to be 2,000,000 tons annually. Four coal seams, all above drainage, are included in the lease. The Middle Coalburg and Stockton are being deep mined now and it is in those mines that the diesel haulage equipment was introduced. This paper will endeavor to trace the steps loading to the introduction of the first diesel-powered Wagner Mining Equipment Company ScoopTram in a coal mine in America. It will further elaborate on the features which make this unit a very versatile and useful utility unit as well as the safety features which are incorporated in the machine. The success of this first unit led to the placing of

Jan 1, 1972

By R. Venkataramani

Even though the mining industry in 1966 produced more ore than ever before, current extraction rates are only a fraction of what is expected in the later years of the twentieth century. Nearly 90% of all metals and-mineral products consumed last year was recovered by open-pit mining. This has placed great pressure on this segment of the industry which has, consequently, resulted in some spectacular developments. With increasing size of projects, the need for increased sophistication of engineering, planning, management and administration of modern mining installations has never become more apparent. The design of complete systems for the mine and plant that fit the mould of today's business and social environments is undergoing an evolutionary process. Traditional concepts in mine development and operations are being sidestepped in favor of new ideas and principles. As the overburden thickness increases, materials handling presents a major problem to mining companies, especially those concerned with the mass production of ore and waste from low-grade deposits. The profit margin here is likely to be significantly less as to take chances with capital investment. 1 Constant efforts are needed to improve upon productivity if the ore is to be economically mined.

Jan 1, 1970

By Jerry L. Fuller

Fan performance graphs are generated by digital computer using two programs, RUN- FANS and FANPLOT. RUNFANS calculates fan performance data from stored specific-volume, specific-speed data for a given fan type with appropriate allowances for fan diameter, rotational speed and air density. FANPLOT accepts specifications for drawing the graph and accepts either user-supplied pressure-quantity data or RUNFANS- calculated data as input, Operational procedures for both programs are detailed and examples of their interactive query routines are included. The hardware necessary to generate the graphs is illustrated. Several hardcopy output options are discussed,

Jan 1, 1984