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The introduction of computer technology to the mining industry has produced many benefits for the mining engineer. The most significant is the dramatic increase in productivity realized by the individual user. This is important during times of competitive market conditions. Software for the minerals and energy industries has evolved substantially over the past decade. But even today it remains difficult to find a system that features the flexibility and integration capabilities to effectively (and cost-effectively) handle the needs of professionals in each phase of the mining industry - from exploration to reclamation. Several national software developers are now addressing this challenge. One Denver-based company, MINEsoft Ltd., offers a software package that is currently being used in each phase of the mining industry. The basic technology used in MINEsoft's database management system was developed in the 1960s. But during these early years of the computer industry, most of the technology was available only on mainframe computers, and then only as separate entities. MINEsoft's system unifies these various systems in one package that can be used on most computers manufactured today. Database Management System TECHBASE is a flexible, integrated database management system designed specifically for technical applications. The system features a database manager with no practical limit to the amount of data it can store, retrieve, and manipulate, according to the company. TECHBASE in¬cludes Applications Packages (TAPs) designed to meet the needs of professionals in a host of industries. Clients use the TECH BASE system to prepare many reports, including important EPA information. The package reduces data to a manageable level and enables users to increase productivity with a smaller staff. Mining engineers no longer need to do things by hand. What used to be a day's work can be accomplished in an hour or two. Exploration "Using the TECHBASE system to generate maps has probably saved us the expense of three or four draftsmen," says Ralph Fitch, regional manager and senior staff geologist with Chevron Resources in Portland, ME. "The system has great flexibility. You can treat it much like a spreadsheet. If you are halfway through with a particular project, the system allows you to add fields and calculations with ease but without starting over." Fitch uses TECHBASE for the "straightforward" plotting of results and generation of geochemical and geophysical profiles. "In exploration," he says, "these are the two key elements ... the generation of maps and data profiles. The system allows you to plot as many elements and variables in these areas that you like." Other aspects are important, too, says Fitch, including drill hole sections. "We use all the basic capabilities the system provides in the complete package," he explains. "When shopping for a system, TECHBASE was clearly dedicated to exploration in the

Jan 9, 1987

By T. Lilley

The use of membranes in wastewater systems has increased rapidly in recent years. Microporous or semi-permeable barriers augment conventional chemical or biological processes to meet stringent treatment targets. These developments enable elegant solutions to wastewater discharge challenges and extend the scope of water recycle redressing the overall water balance and operational economics Wastewater treatment processes are discussed by reference to the spectrum of waterborne contaminants and the respective membrane separation capabilities. The role chemical pre-treatment to enable physical separation of metals with micro-filtration (MF) is described and how integration of MF with reverse osmosis (RO) is used to control a broader range of dissolved contaminants Membrane configurations are considered apropos function, operational economics and sustainability. These features are exemplified with case studies. Firstly, MF alone following chemical precipitation for the removal of heavy metals, then MF onto two stages RO of different configurations for TDS reduction and waste volume minimisation and finally an open channel RO alone for the reduction of inorganic COD from a leach stream.

Feb 27, 2013

By D. C. McLean

One of the few innovations in hydrometallurgy in recent years has been the utilization of the chemistry of basic iron sulfates called jarosites. These have been used to make iron-zinc separations in the processing of zinc concentrates and are a very important factor in both the Duval and Cymet copper chloride processes as a means of preventing iron build-up in the closed leaching circuits. Copper oxychlorides are kindred compounds in that they are insoluble basic salts that form at low pH (1.5 to 3) and precipitate selectively from many base metal solutions. They have been reported in the chemical literature as far back as 1860, and a few of them are known in their mineralogical forms (particularly atacamite) usually as nuisance minerals because of their chloride content. Several patents describe their synthesis and use as fungicides and insecticides, and papers have discussed their formation as corrosion pro¬ducts on copper and brass piping (14).

Jan 1, 1979

By C. A. F. Pinto

In the present work compared flotation kinetics of apatite with four different collectors was established. Sodium oleate and rice bra~ oil were used to represent conventional collectors. The new collectors included a sulfosuccinate and a sulfosuccinamate. It was observed that the collection ability of each reagent was very dependent upon the mineral size ranges. The results-were analyzed in terms of size-by-size recovery curves. Flotation rates were also very dependent on size ranges of the mineral particles. One of the new collectors displayed higher flotation rates for coarser particles than the other reagents tested. Synergetic effects were also apparent when a conventional collector was mixed to a new collector.

Jan 1, 1991

By J. Weng

The equations of heat conduction are numerically solved for two kinds of artificial freezing- mechanical freezing and liquid nitrogen freezing. A two dimensional finite difference model simulating the freezing field is developed. The procedure introduces a way to simulate the effect of latent heat released when water transforms from liquid to solid. The procedure also produces a way to calculate the harmonic mean of heat conductivity used when dealing with heterogeneous material. The theoretically derived temperature distributions in frozen soil are given and compared with measured data. An analysis is made on the thermal design in shaft freezing. The average temperature of frozen soil is calculated by using numerical integration. The regularity of development of frozen soil radius is revealed and given in an appropriate mathematical model.

Jan 2, 1984

By Dan Eyde

Low levels of thallium were detected in the mine water drainages, and process water discharges of western mining and smelting operations. This required remediation under state regulatory standards, which allow discharges of no more than .0017 ppm thallium in mine water discharges. Influent streams containing thallium can be mitigated to state discharge standards after a single pass through the series of fluidized upflow columns. Test work to determine the optimal flow rates used pilot scale systems at two separate locations treating 5 - 25 gpm of effluent. The test system at the gold mine mimics the full-scale system, which will be based on the existing upflow carbon tanks that have been converted to zeolite columns. The system installed at ASARCO's East Helena smelter has a far more complex influent stream with a high loading of competing cations. Nevertheless the columns filled with CABSORB® are successfully mitigating the thallium contamination. CABSORB® ZS500RW is a product based on the sodium analog of the zeolite mineral chabazite named herschelite.

Jan 1, 1998

By R. A. Jankowski

Although the number of operating longwall mining systems has remained relatively consistent over the past five years, longwall production levels have increased significantly during this period. Longwall production currently accounts for approximately 50% of U.S. underground coal production. While longwalls are highly productive and offer other advantages, operations employing this method of mining continue to experience dust compliance problems. This increased longwall productivity has meant that far more dust is being produced. An improved understanding of the longwall face ventilation system and advancement of face ventilation technologies are necessary to ensure all face personnel are allowed to work in an environment that is free of excessive levels of airborne respirable coal mine dust. The Dust and Toxic Substances Control Branch of the National Institute for Occupational Safety and Health's Pittsburgh Research Laboratory has examined several basic principles of the longwall face ventilation system, and has evaluated the effectiveness of numerous improved face ventilation techniques for longwall mining systems. These include identifying improved techniques for measuring face ventilation parameters on longwall mining sections and investigating the fundamental relationship between face air flow and the entrainment and dilution of respirable coal mine dust. Studies have been completed to determine the impact on face dust levels from using belt entry air to ventilate the longwall. Novel methods have been identified to increase the amount of face air flow and to manage face air flow to most effectively minimize face workers' dust exposure. Unique systems of auxiliary face ventilation have been developed and evaluated at full-scale, simulated longwall test facilities. The theoretical and applied aspects of each of these principles and technologies are discussed. Application of these results, throughout the longwall mining industry, as documented from surveys conducted in the early 1980's and 1990's, have reduced the health hazard associated with excessive exposure to respirable coal mine dust.

Jan 1, 1998

By G. Jalkanen

Parameter estimation of the inverse distance estimation algorithm is presented. The objective function to be minimized is a sum of squared cross validation errors. The unknowns to be estimated are the exponent of the inverse distance estimator and anisotropic angles and ratios that are used in determining the distances in the algorithm. Examples are presented for both two and three dimensions data sets.

Jan 1, 2009

By A. G. Provost

On April 3, 1981, Harrison Western Corporation was awarded a contract by Amax Alloy - A Division of Amax Inc., to sink the Henderson #5 ventilation shaft. The project was located on the Henderson Mine site 88 kilometers west of Denver near the town of Empire, Colorado (Figure I). The Henderson No. 5 Shaft, located in an Alpine environment at an elevation of 3145 meters, was a 9.8 meter diameter concrete lined shaft with a total depth of 793 meters. Work started and continued with Harrison Western employees until January 15, 1982. At that time, Amax made the decision to continue the shaft-sinking with their own labor, and with Harrison Western providing supervision under a management service contract. Shaft sinking continued under this arrangement to October 1, 1982, at which time Amax put the Henderson No. 5 project on standby status until further notice.

Jan 1, 1986

By D. M. Jepsen

One of the first things we tell a potential new client is that they have only one chance to make a first impression with an Aboriginal community; all future communications and engagement will be predicated on that first impression. The key components of this most critical meeting are not your power point, your maps, or your draft plan for development ? they are instead a genuine, evident and clear demonstration of a sincere desire to develop a positive relationship that is based upon respect, and consideration and understanding of local communities and their interests, needs and desires. Relationship building is the foundation of proactive and positive consultation and accommodation with Aboriginal communities and the tone is set with the first meeting. C3 has refused more clients than we have accepted due most often to the fact that relationships between the company and the Aboriginal community have already devolved into a tense and toxic scenario. Land access and tenure certainty for exploration and mine development is critical to the foundation of a healthy, sustainable and environmentally and economically sound mineral exploration and mining sector. Without certainty confidence to invest in mineral exploration will be severely eroded. We all understand that substantive investments in exploration are required to increase the possibility of discovering, defining and developing new mines. The development of positive relationships based on a shared commitment of understanding, mutual respect and trust by Aboriginal Peoples and the mineral sector can provide the required business certainty and deliver social and economic benefits for local Aboriginal communities.

Jan 1, 2012

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 C. E. Capes

The spherical agglomeration process provides an attractive method for the cleaning and recovery of fine coals in the form of compact oil-bonded pellets. In treating a washery effluent containing 50% minus 20 micron material by this technique, the slurry was first mixed under vigorous agitation with oil to deash and dewater the fine coal. The flocculated coal pulp was then formed into larger agglomerates on a modified balling disc. The operation of a semi-pilot scale process is described and an analysis of some of the operating and system variables is given. A semi-theoretical expression to predict the final agglomerate size under various conditions is derived and compared with the experimental data. Coal producers are faced with a growing requirement to clean and recover fine mesh coals. Greater mechanization of the extractive and preparation processes has resulted in finer-sized products containing larger quantities of associated foreign matter and preparation plant effluents contain quantities of fine coals which are potentially valuable. These losses will probably increase with the expansion of production and will require the development of effective disposal and utilization processes under pressure of the lack of adequate disposal areas, the enforcement of air and stream pollution laws, and the economic need to obtain the maximum yield of salable product(1)

Jan 1, 1970

By Levent Ozdemir, Charles Merguerian

Between 1996 and 1999, a high-performance Robbins TBM [235-282] excavated a 5 mile long, 23´2? wide, and ~700´ deep tunnel through the subsurface of southwestern Queens. Low penetration rates (~6´/hr [actual] vs. ~9´/hr [anticipated])resulted from changed rock mass conditions mostly attributable to high-grade metamorphism of the rocks. Over a three-year period, as-built circumferential geologic mapping (scale 1?=10´) and digital imagery of the tunnel, fracture and fault analysis, structural, lithologic, and petrographic studies have shown that the rocks of the Queens Tunnel consist of orthogneiss of mesocratic, leucocratic, and mafic composition. These metaigneous rocks developed coarse-grained fabrics during Grenvillian (~1.0 Ga) granulite facies metamorphism, and retained their nearly anhydrous, poorly foliated character during subsequent high-grade Ordoviciande formation. Lacking a penetrative foliation, the coarse granoblastic rock texture and extraordinary garnet content (up to 50% in some zones) together proved animpediment to efficient chip production and resulted in bimodal production of blocks and excessive fines. TBM excavation of the Queens Tunnel was also hindered by geological conditions that included unexpected lithology and rock fabric orientation, a zone of crosscutting hypabyssal rhyodacite dikes, and unanticipated extent of brittle faults. The dikes and brittle faults produced blocky ground conditions and a collapsing face condition that produced cutter damage and decreased utilization. Such fundamental textural, mineralogic, and lithologic control over hard-rock TBM penetration can be predicted by careful pre-bid geological analysis. To determine the causes of lower than anticipated TBM performance, a detailed investigation was carried out that included analysis of operational data from the TBM data logger and an extensive laboratory test program on cores retrieved from tunnel walls. Integrated laboratory testing included punch, point load, tensile strength, Cerchar abrasivity, and linear cutting tests, independent petrographic analysis and machine performance analysis. These allied investigations have provided quantification that the rock mass exhibited an unusually high degree of toughness and rock directional properties and established geological causes for decreased TBM penetration rates.

Jan 1, 2003

By W. M. Middleton

The exploiting of geothermal steam is a new endeavor in this country and is for that matter a very new science in the world. With the majority of steam wells in the world having been drilled during the last twelve years relatively little experience and knowledge has been gained that can guide us as compared to the techniques the oil and gas producers have developed for their use. We few technical personnel associated with the field find it a continuous challenge to understand and explain what effects or causes the various unusual phenomenon experienced. We have had unending discussions attempting to formulate pet theories which we can use as guides. We know, so the geologists tell us, that the source of the heat is from the hot magmatic core of the earth. Theory has it that the magma is cooling off and that hot gases are given off as this magma cools and shrinks. In volcanic' areas along fault lines where the magma reaches closer to the surface than in other areas, there is a higher concentration of gas evolution; consequently, geyser or geothermal areas are developed. As these hot gases rise toward the surface they encounter various minerals, including overlying bodies of water. It is into these underground lakes that our wells are penetrating. As the heat enters these lakes it spreads out by conduction, convection and water migration. We can strike this hot water over quite large areas in many of the geothermal fields. At present there is one anomaly to this in the United States as there is in Italy where our wells do not penetrate a hot water lake. This is at The Big Geysers in California. Here superheated steam is produced with a heat content, so high that it could not have been boiled off of a fresh water pool. This puzzled us until last year when a well was completed into a large body of brine in the Imperial Valley. This brine exists at close to 500°F and at a hydrostatic pressure sufficient to preclude any boiling. It is now believed by some of us that a similar pool of brine must exist below The Big Geysers area, from which the steam is emanating. If there is such a brine pool, it offers a plausible explanation of the high-heat content, for brine boils at a higher temperature than fresh water. I am now beginning to think that a similar brine pool may exist under all the geothermal basins for if it is under two of them, it is highly probable that it is under the others. The partial understanding of what we are drilling toward, and formulating a theory to explain its behavior helps guide us in our steam well drilling.

Jan 1, 1963

By Peter I. Brooker

The turning bands method for the simulation of spatially correlated data in two or three dimensions requires that the relation- ship between the covariance obeyed by the realizations first generated on lines, and the covariance of the two or three dimensional process must be solved. In three dimensions the solution is immediate, but in two dimensions the integral equation relating the covariances of the one and two dimensional processes is more complex. This is solved in this paper and is applied to the most common model used in ore deposit description, the spherical covariance.

Jan 1, 1984

By C. W. Schultz

The Alabama tar sands of the Hartselle Sandstone formation present a more difficult problem in primary extraction than do the Athabasca tar sands. In contrast to the Athabasca tar sands, the Alabama tar sands are "oil wetted" and the contained tar, or bitumen, is of much higher viscosity. A physical beneficiation scheme was developed in which clean sand from an external source was used as a scrubbing medium. High intensity scrubbing liberated the tars which are readily recovered by froth flotation. Locked cycle tests have shown that, after the use of an initial ration of clean sand, the system produced enough new clean sand to be self sustaining.

Jan 1, 1992

By J. E. Urosek

In October, 1990, a fire started in a large underground coal mine in Western Pennsylvania. During fire-fighting activities, an explosion occurred and all personnel were evacuated. Safe re-entry into the mine was not possible and the mine was sealed. Recovery efforts began in January, 1991 and continued until March, 1991, when permanent underground seals were installed between the fire area and the mine openings. This paper describes an extensive atmospheric monitoring program conducted by the Mine Safety and Health Administration (MSHA), Pittsburgh Safety and Health Technology Center (PS&HTC) including the analysis of mine fire gases, natural ventilation, fan pressure and air quantity distribution.

Jan 1, 1993

By Brent K. Nelson, D. Lee Petersen, Charles R. Nelson

INTRODUCTION Tunnels are commonly constructed in the very weak St. Peter sandstone in the Twin Cities area of Minnesota. Historically, core recovery in this weak sandstone was very small in the critical weaker strata resulting in little preconstruction information on the ground conditions. Improved core recovery techniques have been utilized for recent projects, allowing rock quality rating methods to be developed for the recovered core. Down-the-hole tests, and the use of combination ratings between different types of core data provide for more detailed characterization of ground conditions. THE ST. PETER SANDSTONE The 45 m thick St. Peter is an unusually pure quartz sandstone. It underlies all the Twin Cities area, except where it has been eroded by the present day Mississippi River or by pre-glacial rivers. It forms conspicuous steep bluffs along the Mississippi River where the upper Platteville limestone formation protects it from erosion. Where the Platteville formation is missing, the sandstone slopes are often more gentle. Natural case hardening of the exposed sandstone bluffs often forms a resistant crust and reduces sloughing. This case-hardened surface is not representative of the sandstone back from the bluff.

Jan 1, 1987

By Warren D. Stanford Stanford

Introduction The Sleeper mine is a near-surface gold mine located in a remote area 56 km (35 air miles) northwest of Winnemucca, NV (Fig. 1). The deposit was discovered in 1984 by an Amax exploration geologist. Favorable drilling results led to feasibility studies and metallurgical testwork. Final evaluation of the mine potential proceeded very quickly. The project received Amax board approval in July 1985. Eight months later, the process plant was fully operational. The first gold ($1 million) was shipped one month later, in March 1986. Total plant capital was $27 million. Payback was achieved in six months. The Sleeper mine was expected to produce 1.6 t (53,000 oz) of gold and 1.3 t (41,000 oz) of silver annually. However, the ore body exceeded all expectations. Production for the first 10 months of operation amounted to 4 t (128,000 oz) of gold and 2.9 t (94,000 oz) of silver. Direct cash operating costs are in the $1.77/g ($55 per oz) range. Amax is actively conducting exploration nearby for additional reserves to extend the mine's life. (See update on page 242.) Geology The Sleeper gold deposit is located on the northwestern flank of the Slumbering Hills and in the Awakening Mining District. Rocks exposed in the vicinity of the deposit are interbedded siltstones, sandstones, and limestones of Triassic age. They are overlain by latite lava flows and tuffs of Tertiary age. Dikes and sills of latite and andesite intrude the sedimentary rocks. Quaternary deposits of mostly sand with minor gravel and clay cover a pediment containing the gold deposit. The sedimentary and volcanic rock units have been transsected and offset by extensive north- northeast trending faults and less abundant northwest trending faults. Both fault systems fractured and prepared the ground for subsequent invasions of mineral-bearing hot spring geothermal waters. The hot spring systems produced widespread hydrothermal alteration and gold mineralization at silicified centers near feeder fault structures. The deposit is hosted by siltstone and latite that have been hydrothermally brecciated. The main breccia is elongated north-northeasterly. The hydrothermal breccia zones appear to dip steeply to the west. Gold mineralization consists of native gold and electrum deposited in two or more high-grade quartz-breccia veins. Lower grade gold mineralization occurs

Jan 4, 1987

By Stephen P. Mulqueen

Searles Lake is an evaporite basin located near the community of Trona in northwestern San Bernardino County, CA. Searles Valley Minerals Operations Inc. (SVM), a subsidiary of Nirma Limited, currently manufactures more than 1.58 Mt/a (1.75 million stpy) of industrial minerals from natural brines produced from several lakebeds within the basin. The chemical manufacturing facilities in Searles Valley represent extremely complex operations involving solution mining and mineral extraction processes.

Jan 1, 2012