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By Theodore J. Williams

Computer control has been one of the fastest moving and most glamorous fields of industrial development in the past decade. A review of this period shows some truly remarkable accomplishments in both system development and applications. In addition, work now under way promises results which will continue the rate of progress of the past. This paper will review the history and status of the field of computer control and point out the major breakthroughs which have occurred. It will analyze the present trends and extrapolate them to predict the early future developments in the field.

Jan 1, 1968

By James J. Fallon

The industrial minerals industry is defined loosely and a specific list is presented. Criteria by which to judge prospects and examples are provided. General trends of the industry are observed.

Jan 1, 1984

By Eugene M. Trisko

Presentation Overview State-Of-The-Art Scrub/Switch Analyses > Allegheny Power System > PSI Energy UMWA Phase I Coal Interests > 16 Phase I Scrub Plant Coal Profiles > Coal Price/Emission Allowance Interaction Southern Company Case Study > 2+ Million Ton Phase II Allowance Purchases > 10+ Million Ton Phase I Coal Switch > Georgia PSC Proposed Fuel Price Cap > Shift/Avoid Georgia Scub Costs Through System Allowance Purchases

Jan 1, 1993

By Arthur L. Raub

During the last decade, there haven't been any great innovations in the design features of a copper concentrator. What has worked well in the past continues to work well, so that major breakthroughs have been minimal. Conservatism in the ranks also plays an important part. As a copper concentrator is not designed and built everyday, Davy was elated to have an important part in this project. This is the story of the design of the oracle Ridge Project located north of Tucson on the back of Mt. Lemmon at an elevation of 5,900 feet on the N.E. slope of the Catalinas. The Oracle Ridge property, formerly known as the Control Mine, is owned by Oracle Ridge Mining Partners, a joint venture between Continental Materials Corp. of Chicago and Union Miniere of Brussels, Belgium; both or¬ganizations specializing in the non-ferrous metal industry.

Jan 1, 1979

By C. G. Cunningham

The Marysvale volcanic field of west-central Utah contains large areas of argillically altered rocks (fig. 1) that, in turn, enclose smaller areas of fine-grained, medium-grade, replacement alunite deposits and coarsely crystalline, high-grade vein-type alunite deposits. The largest replacement alunite deposits are [ ] located peripheral to a 23-m.y.-old monzonite stock called the Central Intrusive (fig. 1). The deposits formed in near-surface, highly oxidizing environments at the tops of hydrothermal plumes that were spaced irregularly around the stock. The deposits are horizontally zoned from alunitic cores through kaolinitic to propylitic envelopes. Vertically, characteristic alteration minerals progress from a pyrite-propylitic alteration assemblage at the base, upward through alunitic, jarositic, and hematitic assemblages to a flooded silica cap as shown on figure 2. The silica caps are cut by hydrothermal explosion breccias. d34Sso4 values of + 11.5 to + 15.4 permil indicate that sulfur in the hydrothermal plume was derived from underlying Mesozoic evaporites. The sharp upward transition from pyrite- propylite to alunite probably marks the paleowater table, and the top of the flooded silica cap represents the paleoground surface. Basin-Range extensional tectonism began shortly after alteration, and buried the replacement alunite deposits in basins beneath sediments eroded from uplands. The deposits were only recently exhumed.

Jan 1, 2013

By V. R. Degner

The minerals industry trend toward very flotation machines, exceeding 10 m3, began in the late 1960's and responds to the continuing desire to achieve better plant economics through improved plant floor-space utilization, power requirements, and operational /maintenance manpower heeds. In general, as process design tonnage increases, the benefits of the larger flotation machine becomes more evident. The development of the larger flotation machine can be distingushed from earlier, smaller, machines in demanding a rational "scale-up" procedure to guide the basic design, thereby producing a machine prototype capable of satisfactory-operational evaluation at minimum cost. Proven flotation machine "hydrodynamic" scale-up consideration, successfully applied in the development of both the WEMCO No. 164 (28.3 m3) and No. 190 (42.5 m3) machine will be reviewed, and the resulting economic benefits of large flotation machines in high tonnage applications will be summarized.

Jan 1, 1985

By Amri Priambodo, Ian Leslie, Valérie Laflèche, Agustina Ratnaningrum, Robin Paine, Andrianus Sinaga, Willem de Beer

Freeport Indonesia consists of surface, civil and underground mining areas exposed to numerous geotechnical risks and hazards. PTFI uses various monitoring systems (Micro-Seismic, Firefly Light System, Mira Geoscience machine learning, etc.) to effectively manage these risks. The significant volumes of data from these sensors must be integrated into actionable information to provide the expected risk management. This occurs at the GeoEngineering Integrated Monitoring Centre (GIMC), a centralized department within the GeoEngineering Division, tasked with the responsibility to manage all geotechnical monitoring systems. The main hazard the GIMC is responsible for managing in real time is mine seismicity within the underground mining areas and the potential impacts on safe operations. Seismic system engineers achieve this objective through 24 hours a day and seven days a week operations of the GIMC, providing a centralized point of communication, alerts, evacuations and control during seismic events and emergencies. This paper will describe how the GIMC achieves its goal using reliable procedures and strategies based on detailed Triggered Action Response Plan (TARP), concise communications, novel technologies (FireFly Lighting System), and proven seismic re-entry programs to manage risk within the underground mining operations. The integration of geotechnical monitoring and reporting into a centralized group has improved the effectiveness and management of seismic risks and hazards at PT Freeport Indonesia (PTFI) mining operations.

Apr 26, 2022

By Edmond J. O’Donovan

South Bulga is a new longwall operation located in the Hunter Valley coal-mining region in Southeastern Australia. The mine’s objective is to achieve productivity levels significantly higher than the current industry average. From the day longwall production began, South Bulga’s output was below both budget and industry expectations, primarily because of the poor performance of the conveyor system. In the past, conveyor systems have been seen as an adjunct to the mine plan, not as an integral part. At past production levels, this approach may have been acceptable. In today’s mining operations, the conveyor system must be treated as integral and vital to the mining operation. The conveyor system is analogous to the vascular or circulatory system of the human body. Of itself, the system does not do anything, but if it is not functioning satisfactorily, the mine cannot operate.

Jan 1, 1996

By Steve Kral

In recent years, junior mining companies, mostly listed in Canada, have taken a beating in the finance markets. Simply put, potential investors have been leery of sinking millions into exploration and mining projects due to volatile commodities prices and an uncertain regulatory climate in developed and developing countries. The 2014 edition of the Prospectors and Developers Association of Canada (PDAC), however, seemed to be a bit different for some juniors. Equity valuations have improved and metals prices appear to be stabilizing. So, for some of the stronger junior companies, there is some hope. Merger and acquisition (M&A) activity is picking up and, believe it or not, companies are raising some capital. Billed as the largest annual mining meeting in North America, the PDAC conference attracted more than 25,000 mining and exploration professionals from around the world. Organizers were anticipating attendance to break the 30,000 mark. But, given the state of the exploration end of the mining business, 25,000 is still a respectable number. Junior companies that are in the project feasibility stage, or have made promising discoveries that stand a good chance of proceeding to production, are being looked at by potential investors. Those are the survivors of the last three years of dismal M&A activity. On the other side are the juniors that are still around ? and there are plenty of juniors that were at the PDAC last year but have since disappeared ? but have little or no working capital. One analyst calculated that there are about 850 companies with less than $200,000 in working capital and about 600 with negative working capital. This will likely result in fewer junior mining and exploration companies as the year progresses but the ones that remain should be stronger.

By J. L. Moreno, A. L. Williamson, R. D. Bartlett

Large open pit mines in desert climates, such as the Phelps Dodge Morenci copper mine in Arizona, can create groundwater cones-of-depression of considerable size and stability. The hydraulic containment provided by the groundwater depression prevents migration of process solutions into the surrounding regional aquifer. Copper leach operations that fall within the groundwater depression may not require costly lining if passive containment can be demonstrated. An approach is presented in this paper that was successfully used to demonstrate passive containment. The approach includes a combination of groundwater modeling and a water balance analysis of leaching operations failing within or immediately near the open pit.

Jan 1, 1999

By S. Ragab

The objective of flotation models is to predict the recovery rate of minerals from a flotation cell. In this paper a CFD?based flotation models is presented. The model uses first order rate equation, and the collision frequency is estimated using Abrahamson [1] model with input from CFD two-phase simulations. Spatial distributions of dissipation rate and air volume fraction (also called void fraction) are determined by the two-phase hydrodynamic simulations. Knowing these parameters throughout the machine is essential in understanding the effectiveness of different components (rotor, stator or disperser, jets) on the flotation efficiency. Not only the average pulp recovery rate can be estimated but also the regions of high/low recovery rate can be identified. The CFD-based flotation model presented here can be used to determine the dependence of recovery rate constant at any locality within the pulp on particle diameter, particle specific gravity, contact angle, and surface tension.

Jan 1, 2012

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

Jan 1, 1986

By Peter Krag, Rob Henson

It is well known that titanium and zirconium alloys offer superior corrosion resistance in the oxidizing sulfuric acid environments present in sulfide pressure leaching operations. The use of these materials is limited, however, due to their pyrophoricity; several accidents attributed to titanium equipment have been described in technical literature, and other, minor incidents·occur regularly1 • We describe an application of a commercial titanium alloy, Nb-55 Ti, with suitable mechanical properties, corrosion resistance similar to Grade 2 Ti, and featuring a significantly reduced field of ignition conditions

Jan 1, 1992

By J. Eldridge, A. J. Carter, D. N. Leavell

Minpro International has developed an innovative, flexible¬shaft impact crusher that produces glass aggregate from mixed¬color, post-consumer glass. The crusher operates with low power and generates a subangular aggregate, with minimal fines. Output is screened to yield sized aggregate, which can be used directly as surfacing material in Owens Corning's shingle process. Metal, plastic and paper waste is preferentially removed by the Minpro system. Duval County and the City of Jacksonville collect more than 12,000 tons of glass bottle waste per year. It is anticipated that a successful end-use application by Owens Corning, will allow increased collection and cost-effective glass recycling in north Florida.

Jan 1, 2002

By G. V. Sullivan, B. E. Davis, T. O. Liewellyn

A technique was devised by the US Bureau of Mines to recover coarse [+1.2-mm (14- mesh)] North Carolina phosphate now discarded as waste. Concentration utilizes the difference in particle sphericity between the relatively flat calcite and the rounded phosphate pebbles. Sizing, treatment in a continuous hydraulic classification system, and grinding upgraded a 17% P,O5 reject to 4.5% P,05 with a phosphate recovery of 63%. The CaO: P2O5 ratio was reduced from 2.49 to 1.66.

Jan 1, 1987

By J. B. Gwiazda

In designing mine workings and adequate roof supports, it is indispensable to determine properties of the strata surrounding the workings. The proper selection of roof supports is based, before everything else, on a thorough knowledge of the roof rock strength, especially tensile strength. This parameter is a vital factor in the delamination of roof rocks and eventual cave-in. It is also important to know the properties of the floor on which the roof supports are set. While driving galleries, it is essential to know beforehand the strength of rocks that will be encountered in the near future during the work. The devices described will help to obtain this information.

Jan 1, 1987

By Richard Druesedow, Richard Ray

Tests at the VP-5 "C" shaft fan installation of Island Creek Coal's Virginia Pocahontas Mines were performed to determine pressure drop due to the design of the shaft collar and ductwork leading to the fan. Data from the test locations in the shaft, duct and fan indicate significant pressure losses in the system as well as significant turbulence in the flow. Data taken with a 3-D probe in the fan annulus confirmed the importance of using this type of instrument in turbulent flow applications. This data will be later supplemented with data taken after addition of turning vanes in the 45° turn adjacent to the fan inlet.

Jan 1, 1993

By M. S. Klima, A. P. Pinkerton

Solid-bowl (decanter) centrifuges are used extensively to dewater slurries in a wide range of industries. However, the application of decanters as classification devices is not as common. In this study, the performance of a continuous, pilot-scale, solid-bowl centrifuge was evaluated when classifying an ultrafine coal slurry containing nearly 60% material less than 10 µm. The test conditions included centrifuge howl and scroll speeds, volumetric feed rate, solids concentration and pond depth. Centrifuge performance was evaluated using size selectivity curves and the corresponding performance parameters, along with product yields and solids concentrations.

Jan 1, 2002

By St. E. Deák

Mining activities involve excavation from underground to the surface of large quantities of ore (e.g. uranium and its disintegration products) (Dumitrescu, 2002, 2007). Material with limited content of uranium, deemed as sterile or low-radioactive is mainly stored on the surface. These wastes modify the configuration of the disposal areas and affect the quality of the environment and the landscape. This paper presents both analytical and numerical models related to stability assessment of uranium mining waste dumps. It is focused on the calibration procedure of the numerical models, in order to minimize risk error during stability prediction and avoid long term environment pollution.

Jan 1, 2008

By Alfred W. Hefferan

A longwall face conveyor system serves the primary function as all material handling systems; i.e., to transport material between the source and its destination. However, the conveyor system must provide many other functions as opposed to the traditional belt conveyor system. In this paper, we will attempt to contrast the longwall face conveyor system with a belt conveyor system. In addition, the unique problems encountered along with the solutions to these problems will be covered. Table 1 lists the characteristics required of each conveyor system. The table demonstrates the contrast in the two systems. Both must be designed specifically to encounter its unique problems. The balance of this paper will explain how the longwall face conveyor is designed to address its requirements.

Jan 1, 2000