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By Theodore H. Budd, Douglas J. Heinz

This report concerns the successful construction of Contract No. 287 of the Northeast Side Relief Sewer System for the Metropolitan Sewerage District of the County of Milwaukee. The contract involved the construction of approximately 3316 meters (10,880 feet) of tunnel concrete lined to 1.83 meters (72 inch) internal diameter; 30.48 meters (100 feet) of 1.83 meters (72 inch) reinforced concrete pipe jacked-in-place; a river crossing of approximately 107 meters (350 feet); 197 meters (647 feet) of 1.83 meters (72 inch) reinforced concrete pipe in open-cut; several diversion and flow monitoring structures; and miscellaneous manholes and appurtenances. The contract proposal, which was extremely prescriptive, did allow alternative methods of primary support consisting of precast reinforced concrete segments, steel liner plates, steel ribs with wood lagging, and combinations thereof in designated areas. The specifications required the contractor to designate which support scheme it intended to use. The specifications also required compressed air as a means of ground water control for approximately 2316 meters (7600 feet) of tunnel. The alternative selected in the bid proposal was the support method consisting of steel ribs and wood lagging for 2263 meters (7425 feet) of tunnel and steel liner plates for the remaining section. Shaft supports, by specification, were designed to be steel liner plate with steel ribs varying in size from 4.27 meters to 6.10 meters (14 foot O.D. to 20 foot O.D. ).

Jan 1, 1983

By Theodore H. Budd, Austin M. Cooney

The paper discusses the background and theories of the conditions that led to the settlement of a Lovat TBM mining in an earth pressure balance mode on a recent project in Milwaukee, Wisconsin. The settlement occurred independent of human error and caused the cost of the project to increase 50 percent. The project was mined in the highly congested downtown area in alluvial and estuarine deposits, 7.6 m below the water table with a prescribed contract requirement that precluded dewatering in deference to concern for foundations of adjacent existing buildings.

Jan 1, 1989

By Hutchings AA

This paper describes MIM's experience in arranging and executing project financings for coal projects at Oaky Creek and Newlands and Collinsville and the port facility of Abbot Point.The financings had their origins in the late 1970's and culminated with the opening of these projects during 1983 and 1984.MIM's financing developments therefore span an important period in the development of resource projects in Australia.Resources projects have been growing in both scale and complexity of financing requirements.

Jan 1, 1985

By R. J. Reuss

Mina Maria is a high-grade, underground copper mine located in the Cananea district of Sonora, Mexico. The ore body is a massive sulfide breccia located in mountainous terrain. A major highway and an electric transmission line pass directly over the near-surface ore body. The mine is operated by Minera Maria SA de CV, a joint venture company that is 51 % owned by Empresas Frisco SA de CV and 49% by Cominco Resources International Ltd. Empresas Frisco is the operating partner. Production began in October 1990. The mining method used is undercut and fill. A continuous miner and a single-boom, hydraulic jumbo mine the ore. Backfill is a weakly cemented sand-gravel mixture that is pneumatically placed. The ore is treated by conventional crushing, milling and flotation. The Maria deposit is located about 40 km (25 miles) south of the Sonora-Arizona border and 11km (7 miles) northwest the city of Cananea and the Cananea Mine. The mine portal, at an elevation of 1780m (5840 ft), is on the east side of an important drainage divide. The mill site is situated about 800 m (2625 ft) northwest of the mine on the northwest side of the drainage divide where the drainage is more favorable. Its elevation is 1860 m (6100 ft) (Fig. 1).

Jan 1, 1992

By R. J. Reuss

The ore at this new underground operation is a massive sulfide breccia with high copper values. A major highway and electric transmission line pass directly over the near-surface orebodv. The mining method being used is undercut and fill. A continuous miner together with a single boom, hydraulic jumbo is used for the mining. Backfill is a weakly cemented sand-gravel mixture that is pneumatically placed. The ore is treated by conventional crushing, milling and flotation.

Jan 1, 1992

By S. Chatterjee, F. Suparno, A. Paithankar

Estimating reserves and quantifying resources stand as pivotal and intricate endeavours within the realm of coal mining operations. Intricate geological formations compound the challenges in resource estimation, thereby complicating reserve calculations. The uncertainties tied to geological attributes of coal, encompassing parameters like tonnage and coal quality, wield significant sway over resource and reserve computations within coal mines. This research delves into the domain of geological uncertainties, with a specific focus on calorific value, aiming to numerically characterise resources and reserves within an open-pit coal mine situated in Indonesia. To quantify resources, the coal seam geometry underwent simulation via a multipoint geostatistical technique known as single normal equation simulation. A geologically established coal seam served as the training image for generating 20 equiprobable coal models. To simulate CV, 50 realisations were generated for each simulated coal seam, utilising sequential Gaussian simulation. Deviations of the simulated coal seams ranged from -0.07% to 5.48% in comparison to the training image. The CV simulation yielded an average value of 5,920.29 kcal/kg, accompanied by a standard deviation of 586.54 kcal/kg. However, the average CV spanned from 5,305.26 kcal/kg to 6,526.55 kcal/kg across diverse simulations. For reserve calculation within the context of geological uncertainties, an algorithm rooted in maximum flow graph theory was employed to construct the ultimate pit for the coal mine. Within this final pit, the average stripping ratio was 1.62, coupled with a CV value of 6,019.66 kcal/kg. When juxtaposed with the deterministic model, the findings underscore that the stochastic ultimate pit delineates a more expansive excavation, accompanied by a heightened undiscounted cash flow.

Oct 2, 2025

By Cristhian Vía

El artículo detalla una experiencia de implementación de microequipos trackless para el minado de vetas angostas, orientada a mantener anchos de minado económicamente factibles, rentables y seguros y a reducir significativamente la sobredilución. Se explica el diseño geomecánico para dimensionar aberturas y paneles, y se describe la estrategia de minado en cada operación unitaria tanto como los parámetros de control. Como resultado, se reportaron mejoras en todo el proceso de minado y se redujeron a cero de los accidentes por caída de rocas. Se perfeccionaron los indicadores de seguridad de la unidad, se redujo la sobredilución de 30 a 10%, y el costo de minado disminuyó de 34.17 $/Ton a 20.63 $/Ton.

Dec 31, 2020

By Edward Medina

El presente trabajo señala el método de minado "sublevel stoping" aplicado a través de la perforación de taladros largos ubicados cada 50 cm. en el yacimiento minero de San Rafael, Puno. Esta perforación acorta el tiempo de ejecución y el costo se reduce considerablemente en la preparación de la labor. Asimismo, la perforación radial minimiza la perturbación al macizo rocoso debido a que se realizan menos voladura en los alrededores, como también se tiene menos área expuesta a deformaciones. Finalmente, el uso de los equipos de última generación, permiten controlar mejor la desviación del taladro a mayor longitud, que en años anteriores fue uno de los principales limitantes.

Sep 13, 2001

By Paul Gauthier

Aujourd?hui, avec un faible prix de l?or sur le marché, les opérateurs miniers doivent revoir leur façon de faire. La méthode de minage «Eureka» permet de réduire les coûts de production et d?accélérer la mise en production des chantiers. Les principales étapes du cycle de minage et les problématiques associées à l?utilisation de cette méthode à la Mine Bousquet y sont décrites.

Oct 1, 2001

By José Cipriano Vilca Valdivia

El presente texto describe el método Crys-Explo o Exploración Cristaloquímica -en tanto descubre mineralizaciones de estaño en lugares donde otros métodos no tuvieron éxito. El procedimiento ayuda a identificar las zonas con ordenamiento atómicos específicos relacionados con la ubicación espacial de mineralizaciones de interés económico importantes. Asimismo cuantifica la concentración de los elementos químicos en la cristal estructurada de los minerales como óxidos, sulfuros y silicatos y determina el grado de evolución y su función a nivel molecular específica de cada uno de estos Estado Cristalo-Estructural (ECE).

May 1, 2017

By COURTNEY DE KALB

IRON ore is the cause of the present trouble in Morocco. At least three nations are interested in the outcome and private syndicates have been active. The iron deposits are found in that mountainous northern coast line known as the Rif. This is an uplift that has been cut through, by the northward drainage, representing an ancient land surface. Erosion has produced .a fiordlike coast, which circum- stance has aided contraband' traffic to the tribes dominated by Abd-el-Krim, the chief of the clan of the Beni Urriaguel, near the center of 'the north coast, opposite Alhucemas. The iron deposits are extensive in the territory of the Beni Urriaguel. They were "located," if such a term is permissible, many years ago. The first arrangements, through direct contracts with the tribal chieftains, have been reinforced by compliance with the subsequent code under the Spanish protectorate in 1914. Under those terms, the location had to be made through the Arbitral Commission sitting in Paris. These locations, or "denouncements," were made by the I-louse of Mannesmann, of Hamburg.

Jan 1, 1925

By S. A. Scott

Mintek developed the MinataurTM leach-solvent extraction-precipitation technology as a cost effective, easily operated alternative to conventional gold refining processes. The technology was first commercialized at the Harmony Gold Refinery in 1997 to produce 99.99 per cent gold product and has subsequently led to development of various value-addition steps including the casting of various investment bars, gold wire drawing and gold potassium cyanide powder production. In addition to refining gold to high purity, if an appreciable amount of silver is present in the feed material it is also refined to 99.99 per cent purity. The major advantage that the Minataur? technology has over other gold refining processes is the relatively low gold lock-up and reduced operating costs. The operating cost1as at April 2001 for the expanded Harmony refinery (24-ton per annum gold production) was approximately half that of conventional smelting and toll refining. The extractant employed for solvent extraction is relatively cheap and highly selective for gold, making the technology attractive in situations where significant quantities of platinum group metals or base metals are present.

Jan 1, 2004

Today's largest producer of domestic beryllium oxide, Mineral Concentrates & Chemical Co., Inc., has recently disclosed the basic outline of its unique process of beneficiating beryllium ores to high purity BeO. This process, known as the Mincon process, is a thermic-flotation scheme which has reportedly resulted in a recovery ratio exceeding 90% and in allowing up-grading of beryllium concentrates to as high as 33%. Mincon borrowed a step from the iron ore industry by introducing a pelletizing and sintering stage in their flow sheet at the company's mill at Loveland, Colo. This mill, now operating at full-capacity with three-shifts a day, is still undergoing some minor changes and adjustments in the equipment and chemical reagents.

Jan 10, 1961

By K. D. Watson

"THE Mindamar zinc-lead-copper mine, owned by Mindamar Metals Corporation Limited, is at Stirling in Richmond County, near the south-eastern shore of Cape Breton Island, Nova Scotia (Figure I). It is connected by several roads with the Canadian National railway at Sydney and St. Peters.The deposit is said to have been discovered around 1895 as an outcrop in the bed of Copper brook, but the details are obscure. Not until 1925, when it was optioned by American Cyanamid Company, was it developed underground. Between 1927 and 1938, the 1-nine was operated intermittently by The British Metal Corporation (Canada) Limited, and yielded approximately 200,000 tons of ore averaging about IO per cent zinc, 2 per cent lead, I per cent copper, and small quantities of silver and gold. In December 1950, Dome Exploration (Canada) Limited made an agreement with Mindamar Metaî Corporation Limited, which was exploring the old mine, to assume management and prepare the property for production. Production started in April 1952 with a new mill and a new four-compartment shaft, and between that time and the end of 1954 it has totalled 545,347 tons of ore averaging 5·89 per cent zinc, 1·35 per cent lead, 0·66 per cent copper, 0·032 oz. gold, and 2 151 oz. silver.The Mindamar orebodies are irregular lenses and large veins lying within a wide, almost vertical shear zone of remarkable persistency. The shear zone consists mainly of well-foliated sericite schist derived from siliceous siltstone, and it contains a vast amount of dolomite and magne-site of hydrothermal origin. Most of the ore is extremely fine-grained and some of the high-grade material has a conspicuous thinly layered structure. The metallic minerals, in order of decreasing abundance, are pyrite, sphalerite, chalcopyrite, galena, and tennantite; the gangue minerals, in the same order, are dolomite and magnesite, quartz, sericite, talc, chlorite, barite, albite, and alunite.The geological setting of the deposit is shown in Figure 2. Except along streams and lake shores, almost all of the bedrock is concealed by glacial drift. The group of rocks in which the deposit occurs consists principally of greywacke, siltstone, tuff, brecoia, and Javas, and has been correlated lithologically with the Bourinot group of Middle Cambrian age. A short distance west of the mine, these rocks are in contact along the Stirling fault with conglomerate, arkosic sandstone, and quartzite belonging to the Middle River group of Silurian or Devonian (?) age, which elsewhere in the area overlies the Bourinot group unconformably. The large bodies of granitic rocks in the region, and the large lenticular masses of diorite and quartz diorite associated with them, have been assigned by Weeks (5, pp. 68-69) to the Devonian."

Jan 1, 1949

By B. Philip Shull, Allen W. Cadden, Johanna M. Simon, Michael S. Senior

A 670 linear meter (2,200 linear foot) large-diameter sanitary sewer interceptor installation at depths ranging from 3 to 10 m (10 to 30 ft) below existing grade in an area with a high water table requires careful attention to design and performance of the system during construction. Highly variable soil and rock conditions at the site necessitated the design and construction of various excavation support systems along the alignment. In addition to the subsurface condition challenges faced at this site, the proposed sewer pipe was to be installed between an existing active combined sewer main and a high pressure gas main feeding the nearby city. What better way is there to monitor performance of the system than to require a detailed instrumentation system? Instrumentation system specifications and designs are becoming more commonplace in the industry, but it is always important to sit back and take a look at the whole picture. What are you looking to gain from your monitoring? What pieces of information are useful? What interpretations can you derive from the instrumentation you have selected? This paper will address the instrumentation system used to monitor the 670 m (2,200 ft) excavation from the specification requirements to the implementation and interpretation. This case history will delve into the challenges faced and methods used to overcome those challenges on this particular support of excavation (SOE) project. A combination of soldier pile, lagging and sheeting, and shoring systems was used to achieve the necessary excavation support. In designing the systems, attention was given to the configuration of the bracing system to allow the sections of largediameter pipe to feasibly be installed in the excavation while maintaining the SOE system.

By Sarma Kanchibotla

In mineral industry operations the insitu ore is’separated from the waste rock and is subjected to a series ofprocesses to convert it into a valuable product. Profitability of any operation in this industry depends on how eficiently the insitu rock (ore -I- waste) is converted in to the final product and how much value @ice) it commands in the market. Traditionally, the total process in mineral industry is classt@ed into two groups as mining and milling, and optimised independently without considering the impact of one over the other. This paper investigates the impact of mining operations (especially blasting;) on downstream processes and demonstrates the potential benefits of the “Mine - Mill Blasting” approach through simulations and case histories.

Jan 1, 2000

By Jack A. McQuiston, Thomas A. Cross

Corrosion of equipment and machinery in the coal industry is usually the result of three main agents: acids, chlorides, and abrasion. Acids and chlorides are especially troublesome in coal preparation plants where soluble salts and sulfur in the coal produce a highly corrosive wash solution. Abrasion is common in all operations where coal is handled or conveyed. Together, the acid-chloride-abrasion combination results in some of the worst corrosive conditions found in any industry. The variety of equipment and structures in the coal industry calls for different corrosion control techniques. Table 1 lists the areas of concern for a number of items. Just as there is a wide variety of corrosion problems, there is a wide array of coating materials available. Tables 2 and 3 are selection charts to provide guidance in narrowing down the choices. Experience has shown that a limited number of coating systems work best on coal equipment and structures. These systems are described in Table 4. The good-better-best designation in the table refers to coating system longevity. Good indicates the least costly and shortest service life. In nearly all cases the lowest annualized cost can be achieved by using the coating system rated best, due to the avoidance of costly repaints and unnecessary downtime. The most expensive coating system, though, is worthless unless the coating system is properly applied. Field inspection to insure compliance with specifications is an important aspect, and is a service available from many coating suppliers. Even the best coating systems require periodic maintenance to achieve satisfactory results. Spot rusting from mechanical damage should be repaired annually to maximize the coatingsystem's results.

Jan 2, 1980

The 2-4D window shown above is the base startup window which allows you to begin a new project. ??Setting up the project is the first step ??The next step is to setup the properties to be used in this project

Feb 1, 2008

A case study of a landslide, which threatened vital infrastructure essential for the continuous operation of the Ok Tedi copper mine is presented. The paper presents a detailed description of the land- slide, outlines the assets at risk, and how the issue was addressed. This included the consideration of remedial options and the im- plementation of the most economically sound and geotechnically feasible remedial design which was completed within budget and on schedule. The paper is intended to highlight the responsibility of a mine based Geotechnical Engineering section in providing essential geotechnical investigations, design and professional advice on addressing stability issues in the infrastructure region.

Jan 1, 1997

By Donald N. H. Chi, Henry E. Perlee

Accident cost data bases for all mining sectors covering the period 1975 through 1980 have been created on the PDP-11/70 and VAX-11/780 computers at the Bureau of Mines Pittsburgh Research Center. The total expected costs of the following tangible elements are computed: (a) loss in personal income; (b) compensation of wages from State, Federal, and union funds for disabling injuries; (c) benefits for injuries resulting in death or permanent disability; (d) medical treatment and hospital care; (e) investigation of a fatal accident; and (f) production loss due to accidents involving fatalities or amputation injuries. Each cost record computed contains a reference to the original record in the Health and Safety Analysis Center (HSAC) accident files to permit concurrent analysis. The intended applications include examinations of annual trends in mine accident statistics on the basis of economic loss. This provides an additional perspective on mine accidents. Various examples of the use of these data bases are presented.

Jan 1, 1983