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By John F. Bryce, Fazley A. Azhar

With increasing economic pressures to produce more with less, the material handling industry is turning to engineered solutions to reduce the number of people required to operate its facilities, monitor maintenance trends, pin point problems, increase throughput, decrease downtime, identify weak links in the production system, and increase times between scheduled maintenance. One solution to these problems is to implement a Total Control Solution (TCS) using industrial computers, fieldbus networks, and distributive Input/Output (I/O) for control, automation, data acquisition, and analysis. This paper will discuss some of the control fundamental principles used by Technisys, Inc. (TI) to implement TCS.

Jan 1, 1998

By L. Xiao, P. Somasundaran

Using potassium oleate as a collector and alizarin red S as a modifying agent, selective depression of dolomite from francolite was achieved in an alkaline medium (pH > 9.0). Adsorption of alizarin reds alone on dolomite was found to be higher than that on francolite. Complimentary adsorption experiments of alizarin red S and oleate showed that oleate adsorprion was increased in the presence of alizaring red S. The results are explained in terms of comparative adsorption for the active sites on francolite and dolomite by oleate and alizarin red S and their interactions with dissolved mineral species in solution.

Jan 1, 1990

By C. Cigna, M. Patrucco, D. Savoca, E. Lovera

The paper deals with the activity program and the preliminary results of a research work commissioned by IReR Research Centre and Regione Lombardia to the Department of Land, Environment and Geotechnologies of Politecnico di Torino. The aim is to define measurement, analysis and control criteria for the emission of chemical and physical pollutants from non-metal mining industries, with particular reference to noise and airborne particulates. Such emissions are related to health risks and annoyance problems, both for the working crews and the neighbouring population, and so, in order to get an effective sustainability of the industry, suitable reduction methods and assessment tools are required. A simple technique for the evaluation and forecasting of both the emission levels and deriving impact has been tested at different mining and quarrying sites, considering their differences in terms of layout and exploitation method, the latter ascribed to a series of main typologies as present in Lombardia region.

Jan 1, 2005

By Joel Nonnweiler, David Young, John Hawley

The Sacramento Regional County Sanitation District has implemented a billion-dollar interceptor system master plan, including the 31 km (19 mile) long Lower Northwest Interceptor (LNWI). For the two LNWI Sacramento River crossings, pipe-jack/micro tunnel drives in excess of 300 meters (1,000 ft) from 30 meter (100 ft) deep shafts in mixed soil conditions below the water table were considered, as were600 meter (2,000 ft) tunnel drives utilizing pressurized-face tunnel boring machines. Operation and maintenance concerns, predicted flood scour, and levee concerns are discussed. A risk assessment process was used to select both profile and construction method. Construction will begin in mid 2004.

Jan 1, 2003

By Dale R. Ralston, Roy E. Williams, Gerry V. Winter, George L. Bloomsburg

INTRODUCTION This manuscript is based on site inspections of five existing mines and the detailed analysis of two of the five. The detailed analysis and mathematical models of the two mines are presented herein in order to demonstrate a method of predicting mine water inflow using existing mines as a data base. Water management procedures were studied at all mines. Our original criteria for mine selection were that the mines be less than five years old and have an inflow rate in excess of 2000 gpm (7.6 m3/min). Background hydrologic and hydrogeologic data were required so that two of the mines could be used for our computer modeling experiments. Our original criteria proved to be difficult to meet. We contacted numerous mines via various sources. Many mines were unable to meet the cri¬teria stated or were not interested in cooperating with us. Therefore, we allowed some flexibility in the application of these criteria to satisfy our orig¬inal requirements. Although the visitations at all the mines are not discussed herein the characteristics of the two mines simulated are presented. These simulated mines consist of a uranium mine in New Mexico and a lead mine in Missouri. The mines and owners will remain anonymous by request. URANIUM MINE-CASE HISTORY NUMBER 1 Mine Location The uranium mine that we simulated is located in northwestern New Mexico. The ground surface at the uranium mine is at an elevation of approx¬imately 7000 ft (2134 m) above mean sea level. The climate is arid to semi-arid with an average annual precipitation of approximately 10 in. (25.4 cm) (John and West, 1963). Geologic Setting It is essential that a conceptual model of the stratigraphy, hydrostratigraphy, and structural geology of a mine site be developed prior to simulation by a mathematical model. If such a conceptual model is not developed prior to simulation major errors are difficult to avoid. The uranium mine we have simulated is located in the San Juan Basin (Fig. 68), which is a structural basin located in northwestern New Mexico and adjacent parts of Colorado, Arizona, and Utah. The sedimentary rocks present in the deepest part of the basin are nearly 15,000 ft (4572 m) thick (John and West, 1963). The regional dip of the sedimen¬tary rocks in the Grants area is generally northward toward the San Juan Basin; the regional attitude is modified locally by normal faults and folds (Hilbert, 1963). The rocks of interest in this area are sedimentary in origin and range in age from Penn¬sylvanian to Cretaceous. They rest on the Precam¬brian core of the Zuni Uplift. Associated intrusive and extrusive rocks are of Tertiary and Quaternary ages (Hilbert, 1963). The deepest sedimentary unit of interest at this mine site is the Morrison Formation as described by Hilbert (1963). The Morrison Formation con¬sists of three members in the general area of the mine site; the deepest member is the Recapture. The Recapture Member consists of alternating beds of gray sandstone and grayish red siltstone or mud¬stone with strata up to several feet in thickness. Only a few small deposits of uranium are contained within the Recapture Member. The Westwater Canyon Member overlies the Recapture Member of the Morrison Formation. The Westwater Can¬yon Member is approximately 150 ft (46 m) thick and consists of light brown to gray, poorly sorted, arkosic sandstone, and some interbedded gray mud¬stone. The Poison Canyon Formation denoted in subsequent discussions, tables, and figures was de¬termined to be a part of the Westwater Canyon Member. The separate connotation is used for the description of mining operations and hydraulic properties but a separate physical description is not included. This member of the Morrison Formation contains many large deposits of uranium. This is (some pages in this article are damaged)

Jan 1, 1986

By J. J. Lewis

The chapter describes how several OR techniques assisted the planning of a major new UR project. A computer system was developed to analyze reserves distribution and potential of possible underground layouts, to assist in choosing the location and size of access points. Manpower requirements of each proposed working plan were assessed and matched with the potential recruitment of skilled and unskilled labor. Computer simulations were used to determine the optimum capacity for coal preparation plant and surface bunkerage. For the overall assessment of robustness, financial modelling and risk analysis techniques were adapted to the special requirements of new mines.

Jan 1, 1979

By Paul D. Chamberlin

There are many unit operations applicable to the processing of gold/copper ores. Deciding which are most applicable to your ore can be done using a series of tree diagrams. The diagrams show generalizations, not definitive rules. And the listing of process alternatives on the diagrams is very limited although there are dozens to choose from. Three questions help point the way to proper process selec-tion: 1. How much gold is in the ore? 2. How much copper is in the ore? 3, What is the cyanide consumption when leaching the ore?Halogens can also effectively leach gold ores and gold/cop

Jan 1, 1996

By Maria C. Jaime

Optimization of the rock cutting performance plays a major role in the tunneling operation. For a given set of tool and cutting environment, rock fragments may be chipped away in numerous manners and it is crucial to understand and be able to predict the dynamics at the cutter-rock interface. This paper presents rational and realistic 3D finite element modeling of rock cutting where typical computational issues ?such as contact formulation, appropriate rock material response, mesh distortion, and crack propagation? are overcome. Cutting forces and failure mechanisms in this finite element analysis are successfully validated by laboratory single-cutter scratching tests in sandstone.

Jan 1, 2010

By Robin B. Steven

Rio Tinto's Kennecott Bingham Canyon Mine is one of the largest open pit copper mines in the world. In 1988 they completed a $400 million project using a conveying system to transfer the ore from an in-pit crusher to the concentrator. The longest conveyor, C-6, was 17,352ft long and ran in a tunnel through the mountain-side to the concentrator. The belt was removed after 14+ years after carrying 700 million tons of 10 minus ore. The paper discusses the original G6 belt's performance and new splicing methods used to achieve a 60% dynamic splice efficiency on the replacement belt.

Jan 1, 2004

By John J. Mancini

Elastomeric liner products have been used for over two decades in a wide variety of uses including pond liners, hazardous waste barriers, dam face rehabilitation and mining applications. Asphalt blended with polymers is enjoying renewed interest in the engineering community because of its durability, high yield attributes, fewer CQA steps due to seamless installation, and ease of installation and repair. As in other lining technologies, advancements in polymer chemistry and improvements in installation techniques have had dramatic impact on the quality of fluid-applied asphalt (FAA) membranes. Membrane 6, man­ufactured by Deery Oil, Inc. for over 16 years is a hot-applied polymer modified asphalt membrane that can be applied to a variety of substrates in a reinforced configuration or installed directly on an asphalt surface. By blending thermoplastic polymers with asphalt, very favorable stress/strain characteristics can be achieved (Chambers, 1980). Typically the membrane will yield under rel­atively low stress and also exhibit high elongation capability. In service applications where puncture resistance is a concern, fluid applied asphalt materials have the flexibility and com­pressive strength under heavy loading that leach pad designers may find attractive. Additional security is achieved if long term service life is important as in the case of radioactive waste con­tainment. The Department of Energy selected Membrane 6 over seamed liners for a surface barrier that must isolate and contain radioactive waste for 1000 years. Asphalt has a long history of use as a water-stop material and it is believed that this natural construction material combined with SBS polymers will per-form for a millennium. (Freeman, 1994) The process of installing Membrane 6 varies according to job size and the type of surface to be protected. Lining applica­tions on compacted substrates require the membrane to be applied to a scrim cloth (fig 1). Some early pioneers in FAA technology neglected this step and therefore never achieved per­formance levels that satisfied regulatory guidelines. The scrim provides a cohesive surface that promotes membrane flow while achieving high impermeability (2Xl0 '11).

Jan 1, 1996

Due Dilligance does not only lie in the statistics, but rather in the practical process aspects, which is the window to understanding the statistics.

Jan 1, 2005

By Howard M. Graff

The Inland Steel Company operates five underground iron mines in the Lake Superior District. The two largest of these, from the standpoint of productive capacity, are the Sherwood Mine in Iron River and the Bristol Mine in Crystal Falls, both on the Menominee Range of Michigan. It is at these two mines that we have had our principal experience with belt conveyor installations underground, .At the Sherwood Mine, which has an annual capacity of about 450,000 tons, the first conveyor belt installationwas made in 1947 when conveyors were installed in the main haulage drifts on the 1200 ft, level, It was estimated at that time that approximately 5,000,000 tons would be mined from the stopes above the 1200 ft, level and. that if all this material could be moved to the shaft by belt conveyor, the entire cost of operation, including maintenance and the amortization of the equipment, would be about $,05 per ton, which was slightly more than half of what the cost would have been by conventional tramming methods employing locomotives and cars. Now, ten years later, the 1200 ft, level is almost completely mined out and we have actually removed. 5,200,000 tons and. the average cost of transporting this material to the shaft by belt conveyor has been $.095 per ton. Since there has been a substantial increase in hourly rate of pay and also in the cost of materials since 1947, we feel that the anticipated savings were very nearly realized., The 1200 ft, level installation at the Sherwood consisted of two 36" trunk line conveyors 815 feet long and 380 feet long, respectively, deliverying ore to the shaft. These in turn were fed. by three lateral 36" conveyors which paralleled the sides of the orebody, These gathering conveyors passed under draw points to which ore was brought from the stopes by mea S of scrapers or shaker conveyors, Shaker conveyors were used for a number of years in conjunction with the conveyor belt system of haulage but it was finally concluded that with this particular type of ore, the maintenance on shaker conveyors was excessive. Therefore, more recently, we have gone back to scrapers for the shorter distances and. are using belt conveyors in the scraper drifts for the longer distances. After this belt system had been in operation for about three years, it had proved to be so successful that it was decided to proceed with the same system or. a new level to be opened up 200 feet below. Instead of sinking the shaft and driving a horizontal drift to the orebody on the 1400 ft, level, an inclined conveyor drift was started near the shaft at the 1200 ft. level and driven downwards toward, the orebody at a slope of 15 degrees. The conveyor installed in this inclined drift is 36" wide, 990 feet long, is powered. by a 100 hp motor, and is capable of delivering 300 tons per hour to the 1200 ft, level shaft pocket. It is fed by lateral horizontal conveyors on the 1300 ft? 1400 ft., and 1425 ft, sub levels. Wien the inclined drift was started, the rock was scraped from the breast directly to the rock pocket at the shaft. As the distance increased., double scraping was employed, until the advance had reached 350 feet, At this point a portion of the final conveyor was installed, with a scraper slide near the breast, T e drift was then advanced be scraping on to the conveyor until a sufficient distance had been driven to permit the installation of an additional 200 feet of conveyor. This proved to be a very efficient and economical means of moving the development rock to the shaft and obviated the need of using cars or an inclined skip way, At the present time 85 percet of tie entire mine output is being mined below the 1200 ft, level and is delivered to the shaft via the inclined conveyor. The system appears to be working as well and as economically as did the conveyor systemonthe 1200 ft, level.

Jan 1, 1958

By J. B. Knapp, J. W. G. Betts, Scott L. Burreill, J. H. Bassarear, E. A. Lowe, W. J. N. Davis, John L. Bolles, Gaylord P. Dopson, William H. Keener, N. S. L. Steenkamp

This chapter contains moderately detailed descriptions of some typical and well known mills that treat predominantly sulfide copper ores, some containing secondary values in gold, silver, and molybdenum. The descriptions are general in nature, because most of the specific data will be found in tabulations elsewhere in this section, covering a large number of mills in such matters as flotation reagents, crushing and grinding equipment and steel consumption, thickener and filter operating data, power consumption, and many others, in a manner that the reader will find convenient and comprehensive for reference and comparison. On the other hand, the plant descriptions selected for this chapter emphasize the kind of information that cannot be readily tabulated.

Jan 1, 1985

By M. L. W. Tuttle, B. R. Berger

Our study focuses on the geology, hydrology, and geochemistry of a variety of molybdenum (Mo) porphyry systems. The systems are either high fluorine, granite, Climax-type, systems (e.g. Mount Emmons/Redwell Mo deposit, Colorado and Questa Mo deposit, New Mexico) or low fluorine granodiorite systems (e.g. Buckingham Stockwork Mo deposit, Battle Mountain, Nevada and Cannivan Gulch Mo deposit, Montana). The water quality of streams, natural springs, mine discharge, and ground water from drill holes were assessed in the region of these deposits. The ultimate goal of our study is to understand the environ-mental behavior of these Mo porphyry systems in the context of geologic setting, hydrologic regime, and climate.

Jan 1, 2004

By T. P. Weldum, W. Conger

"The objective of the study conducted by the authors is to determine what media size(s) addition will maximize any given plant ball mill’s grinding efficiency (Fig. 1). The functional performance parameters “mill grinding rate through the size of interest,” and “cumulative mill grinding rates” from both plant and smallscale tests are applied to this task. A plant media sizing methodology, and industrial case studies, are provided.BackgroundA previous article (“Ball mill classification system optimization through functional performance modeling,” Nov. 17, McIvor et al., 2017, Mining Engineering) described circuit classification system efficiency (CSE), equal to the percentage of coarse (plus circuit P80 target size) material in the ball mill. It can be measured and then increased through pump and cyclone adjustments. By so transferring the application of ball mill power from fine (minus P80 product size) to coarse material, circuit efficiency is increased and overgrinding is decreased.The other factor that determines overall circuit efficiency is how well the power that is applied to the coarse material grinds it. This is affected by design and operating variables like the media sizing and mill percent solids. From circuit functional performance (McIvor et al., 1990):Circuit production rate of new fine material (t/h) = Power applied to coarse material (kW) x Mill grinding rate of coarse material (t/kWh) (1)The power applied to coarse material is the total mill power multiplied by the CSE. Therefore:Circuit production rate of new fine material (t/h) = Total mill power (kW) x CSE (%) x Mill grinding rate of coarse material (t/kWh) (2) Production rate, mill power and CSE can be measured during a plant circuit survey. The mill grinding rate of coarse material is then calculated. At the circuit target P80 size, this is the mill grinding rate (of coarse material) through the size of interest. The objective is to maximize this rate. The mill grinding efficiency can also be calculated by taking the ratio of the mill grinding rate over the material’s grindability as measured in the lab. Mill percent solids optimization has thusly been achieved (McIvor et al., 2000). For media sizing, maximizing the mill grinding rate on a given ore is equivalent to maximizing the mill grinding efficiency. Ores of different grindability will be part of the discussion."

Jan 11, 2018

By Dwight K. Smith

Fly ash as an additive for oil well cement was introduced to the oil industry by the Halliburton Company in 1949. Since its early usage in the Illinois area of the U. S., the total amount of fly ash pumped into wells has exceeded 30 million sacks, The advantages of using fly ash-portland cement mixtures in wells are fundamentally the same as for concrete except the conditions of placement and curing are variable and the nomenclature of properties are expressed somewhat differently. In some instances deep wells have been cemented with mixtures of fly ash and hydrated lime together with an activator which functions as a catalyst for setting. This fly ash-lime formula has many advantages for high temperature-pressure conditions found in wells.

Jan 1, 1968

By John Ralston, Rossen Sedev, Nicola Richards, Quinn Anthony, Geoffrey Reynolds

Derivatised 2,4-diketopyrimidine groups have been anchored to planar gold surfaces as self¬-assembled monolayers (SAMs) for chemical and photochemical studies. Three derivatives, 5-methyluracil (thymine), 5-trifluoromethyluracil and 5-nitrouracil, were chosen for the specific moiety present at position C-5, which can exert strong or weak inductive effects on the adjacent aromatic ring. The measured acidity constants decrease from 5-methyluracil to 5-nitrouracil as the inductive properties of the group at C-5 position increase. When grafted to the surface the acidity constants increase, albeit still adhering to the expected inductive trend. The functionality also exerts an influence on the surface wetting properties. Surface wettabilities indicate that the orientation of the pyrimidine groups at the surface occurs so that the C-5 position has a direct effect upon the surface chemistry. Upon dimerisation the surface contact angles increase signifi¬cantly. At pH 11 the contact angle changes reflect that the dimer has a higher pKa than the monomer. The monomer surface is deprotonated at this pH while the dimer surface is partially deprotonated, leading to changes in contact angle of up to 22 degrees. Large changes in contact angle were observed for 5-nitrouracil which were independent of surface charge and were appar¬ently due to conformational changes alone. Electrowetting of three fluoropolymer surfaces by electrolyte solutions was studied with the sessile drop method. The electrowetting curve (contact angle/potential) is analogous to the elec¬trocapillary curve (surface tension/potential) and may be described by a combination of the Young and Lippmann equations. We demonstrate that for some specific surfaces a systematic deviation occurs at positive potentials. This departure is attributed to double layer effects, namely the adsorption of hydroxide and halide anions. pH, ionic strength and polymer composi¬tion can all influence electrowetting behaviour.

Jan 1, 2003

Industry and regulatory agencies have requested guidance on safe blasting near transmission pipelines. The US Bureau of Mines (USBM) and Amax Coal Co. studied surface coal mine overburden blasting near four steel and one PVC pipeline of 15 to 51 cm-diam (6-20 in.-diam), monitoring vibration, strain and pressure. Unlike tests of small blasts simulating construction, these were up to 1 t (2200lbs) per delay in 31-cm (12-in.) blastholes. Worst-case comparisons showed that 12.7 cm/sec (5 in./s) blasting vibrations produced strains about one fourth that of pressurization and 10% to 18% of the ultimate tensile strength. No failures occurred from blasting as close as 15 m (50 ft), which produced vibrations over 60 cm/sec (24 in./s).

Jan 1, 1995

By D. Panias

Alumina hydroxides such as gibbsite (Al(OH)3) and boehmite (AlOOH) are precursors of many types of alumina that find important industrial applications. The thermal decomposition of AlOOH, which is a more energy saving precursor compared to gibbsite, gives rise to the formation of ?-, d-, ?- and a-aluminas that are used for the production of catalysts. The applications of the aluminas are governed by their properties that are a function of the precursor material and its microstructure. The microstructure in turn is a factor of the method and conditions applied, as well as, in the case of soft chemical processes, on the anions present. Towards these ends, this study was focused on the effect of different anions on the physicochemical characteristics of the alumina hydroxides precipitated in the first 5 minutes after the perturbation of the stability of a supersaturated sodium aluminate solution (Bayer liquor).

Jan 1, 2006

By R. A. Speirer, T. C. Bettinger, L. P. Richardson

INTRODUCTION The Bureau of Mines (The Bureau) remote sensing researchers at the Denver (CO) Research Center, have been investigating computerized methods to detect and map surface linear features called "lineaments" for ground hazard assessment in mines. Many of these lineaments at the test mine site were found to correlate to subsurface geologic discontinuities such as faults, fractures, and joints that intersect coal seams at depth. These features adverse1 y affect the roof and rib integrity in underground mines, thus contributing to rock failures that may result in injuries to mine workers and loss of production. Advance knowledge of the existence of such hazardous geologic features can aid in mine planning and development. Lineaments may be observed in a variety of images of the earth's surface. Linear features that can be observed using Landsat mu1ti spectral scanner data (MSS) images range from regional (greater than 3 miles in length) to an intermediate length of from 1 to 3 miles. These images are recorded in discrete radiation bands in the green, red, and near-infrared portions of the el ectromaynetic spectrum. These data are acquired from the EROS Data Center of the U.S Geological Survey, Sioux Falls, SD, in digital format on magnetic tapes that are suitable for processing on certain minicomputers. Shorter lineaments length (less than 1 mile) can be observed in high- to low-a1titude aerial photography, radar, and infrared images with image scale ratios of 1:1,000,000 or less. These linear features can correlate to smaller dimensioned faults, and to fracture and joint sets at the local geologic scale. Other informational sources can help substantiate 1ineament analyses, such as well logs, mine naps, topographic data, and geophysical data acquired over the study site. These data must be in a digital format to process on the "DEC PDP 11/23 minicomputer system1". Data can be acquired in

Jan 1, 1986