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By R. C. Corson

Modern microprocessor systems make it possible to use several variables to anticipate changes in the process and to react with responses before upsets can be magnified by the process or by control action. Through tighter control, "insurance" can be eliminated from process set points without affecting product quality. In actual operation with a traveling grate furnace this control philosophy has produced savings of up to 20% in fuel consumption and 8% in fan power usage while producing a more consistent quality product.

Jan 1, 1984

By L. Michael Kaas

On its tenth anniversary, the computer is a "fact-of- life" in the mineral industries. Its evolution as a practical mining tool was accurately summarized by Alfred Weiss, editor of the Proceedings of the 1969 International Computer Application Symposium, A Decade of Digital Computing in the Mineral Industry: "During the past decade, data processing and operations research developments within the mineral industry have evolved through states typical of any new technique. These have ranged from mere recognition, to cautious acceptance, to confident utilization, and in some instances, to substantial investment in computer hardware and software."

Jan 1, 1970

By C. W. Merrill

Minerals research by the U.S. Bureau of Mines embraces the mining and metallurgical problems of some 80 metals and nonmetals excluding the mineral fuels. It requires the energies and talents of about 1400 persons, almost half of whom are professionally trained in the physical sciences or engineering. Of approximately $13 million appropriated to the Bureau for minerals programs in Fiscal Year 1962, 76% has been allotted to technologic research and 24% to resources examination and appraisal. In addition, almost $2 million will be made available to the Bureau for minerals research from other Government sources and from private organizations that wish to utilize Bureau experience and capabilities in cooperative studies.

Jan 11, 1961

By G. Righettini, P. Mousset-Jones

Diesel powered vehicles have made underground mines more efficient, but with the advent of DPM regulations, in most cases, extra ventilation and/or engine emissions control technology will be required. Using fuel cell powered vehicles will not need these measures to be taken. Nine US underground mines of varying production rates and mining methods were studied to determine possible ventilation reductions if their diesel fleets were replaced with identical fuel cell powered vehicles. Factors that might limit ventilation reductions, such as heat and the effects on other pollutants were determined for each mine. The ventilation cost savings and other benefits of fuel cell vehicles show that when they become commercially available they have the potential of being viable alternatives to diesel vehicles.

Jan 1, 2004

By Shiels O. J

The paper reviews developments in general galvanising in Australia, including a brief history of the industry and its technology. The changes in galvanising process technology are covered, as well as developments in galvanising bath design, materials handling and pre-treatment. Developments in zinc management through the use of aluminium and nickel alloys are discussed. The paper addresses the cost components of general galvanising and relates this to the competitive position of general galvanising against other coatings used for protecting steel. The environmental aspects of the general galvanising industry in Australia are outlined with respect to the utilisation of process chemicals, problems associated with their disposal and developments in filtering and regeneration of process solutions. The current status of the industry is assessed in terms of zinc usage and usage trends. Likely changes in technology which may impact on the general galvanising industry in the future are reviewed.

Jan 1, 1993

By I. Sheinhartz, H. M. McCullough

DURING the course of a lubrication study in relation to the compacting of metal powders, it became desirable to measure the thickness of sprayed graphite coatings on steel dies for hot pressing. The thickness of these lubricant coatings ranged between 0.0001 and 0.002 in. In their particular case, the authors were interested in a method for measuring the lubricant thickness on tapered die inserts having curved surfaces. The lubricant was sprayed on the inserts at an elevated temperature and it was desirable to measure the thickness as soon as possible after application. Various standard types of commercial equipment were tried. Most of the available devices operated on either a mechanical or magnetic principle. The mechanical devices, such as micrometers, dial indi-

Jan 1, 1956

MR JOHN S Foxall wrote: Mr Clayton in his paper on the above subject (Proceedings, N.S. No. 34) made an assertion which should not be allowed to remain unchallenged. On the top of page 10 appears the following statement;- "By viewing the box at adepression angle of 45°, all the dimensions are disclosed and the box may be projected on isometric co-ordinates" and lower down on the same page:- "An isometric plan, being virtually a projection on a plane inclined at 45°, the nearer the dip approaches this figure so is the outline of the stoping more truly shown." Those statements embody an inaccuracy which would be misleading were an isometric plan to be constructed to suit a special case, ie the case of a mine whose lode dipped at 45°, or approximately 45° and it would be found that in such a plan the outline of the stoping would not be truly shown. The reason for this is that the depression angle at which an object is viewed in order to...

Jan 1, 1920

The occurrence is recorded of an indurated kaolinite claystone associated with red-beds in the Burralow Formation of the Narrabeen Group near Putty toward the north-west of the Sydney Basin. The claystone is similar in composition and structure to the Garie Member which immediately overlies the kaolinite-rich "chocolate shales" of the Bald Hill Claystone in the sofrthern part of the basin. Unlike the Garie Member however, the Putty claystone is lenticular and the associated red-beds contain abundant quartz and illite in addition to kaolinite.The source of the Putty claystone is not known. Possibly it is an extension of the Garie Member to the northwest or alternatively, it may represent fine outwash of detritus that produced the coarse-grained kaolinite claystones in the Triassic succession of the Merrygoen-Binnaway area. Although the material is suitable for the manufacture of aluminous refractories the limited size of the deposit precludes its commercial exploitation.

Jan 1, 1971

By David Leidel

A major characteristic that distinguishes modern society from its predecessors is the understanding that events are not driven by the whims of the gods, pre-ordained fate or nature, but are controlled to a greater or lesser extent by the actions, (or inactions), of people. The study of risk assessment is the basis for determining risk or the likelihood of an event occurring combined with the consequences of that event if it does occur. This study is indubitably linked to the mathematics of probability and statistics which permits the quantification of risk. As the Industrial Revolution significantly increased the exposure of persons to new types of energy sources, materials, equipment, and means of more rapid transportation of goods and people, quantitative risk assessment became a vital tool in protecting workers and the general public exposed to these new technologies.

Jan 1, 2007

By M. Georgescu

In the framework of the rapid development of contemporary society, the use of underground space represents an emerging opportunity because it can contribute to decreasing pressure of occupation of ground space while in the same time it can increase the economic value of the useful mineral substances, also through underground establishment of dangerous surface activities, contributing thus in environmental protection. This paper underlines the most important benefits of underground space utilization with the objective the exploit the potential of this real resource.

Jan 1, 2006

By Steven V. Crum, Willard E. Pierce

Concern has been raised about the adequacy of current regulatory guidelines designed to protect homes from unwanted blast damage due to low frequency ground vibrations; in particular those with predominant frequencies below 6 Hz. This report summarizes and updates the preliminary results of a continuing Bureau of Mines investigation which will be completed later in 1995. Four structures at four different surface coal mines have been studied by examining their response to ground vibrations created from overburden blasting. House response to ground vibrations with dominant frequencies down to about 3 Hz were recorded. Many of the blasts produced ground vibrations with peak amplitudes above expected crack-producing thresholds. Response motions were compared to those predicted by theoretical single degree of-freedom response models.

Jan 1, 1995

The commercial outcomes from new mining projects or brownfields expansions often fall short of feasibility study forecasts because of technical under-performance. This paper: reviews past feasibility study performance; identifies the key drivers of underperformance; and proposes actions that can be taken to manage the risk of underperformance. There have been a number of published reviews of feasibility study performance since the 1970s. The results of these studies are summarised together with recent unpublished data. Key drivers of underperformance include inadequate metallurgical testing, simultaneously pushing a number of project parameters beyond comfortable limits and a failure to recognise the linkage between mining rate and head grade. Actions can be taken during the data acquisition phase and during the feasibility study to manage project technical risks. These generally require a more flexible approach to study management than can be achieved under a ælump sumÆ contract.

Jan 1, 2003

By David R. Holberg

In the Kansas City metropolitan area, mineable Bethany Falls Limestone occurs 80 ft below river level under the 700 acre Park College Campus on the north bank of the Missouri River at Parkville. For 20 years prior to this project various firms passed over this opportunity to mine this property for construction aggregate because of uncertain costs, financial risk, and the difficulty of constructing an entry tunnel. This paper describes the drill and blast construction, rock bolting, and shotcrete lining of a 750 ft. long, 15% declining grade, truck tunnel through several Pennsylvanian limestones and shales.

Jan 1, 1997

By F. E. Heuze, R. N. Nilson, R. J. Shaffer, R. P. Swif

As part of the Unconventional Gas Program at the Lawrence Livermore National Laboratory, we are developing a model that allows for time-dependent tracking of the fluid front and flow pressures during the quasi-static or dynamic fracturing of jointed rocks. Application of the model is directed towards both short fast fractures (as in tailored pulse loading) and long hydraulically induced fractures (massive hydraulic fracturing). The thrust of this research is to determine crack extension characteristics due to specific joint systems and fluid properties and to correlate pumping records with crack behavior in jointed systems.

Jan 1, 1986

By H. Firmstone

Deposits of cadmia, or impure oxide of zinc, are of common occurrence in the upper parts of blast furnaces using ores containing zinc, and were very common in the charcoal furnaces of Virginia working the brown hematite ores found near the Cadent black slate. These deposits were known to the old charcoal founders as "sulphur rings," and the characteristic green flame of burning zinc frequently to be seen at the tymp of furnaces working ores containing zinc, was held by them to indicate the presence of a "sulphur fall." When zinc is burning in considerable quantities at the tymp, the

Jan 1, 1879

By I. Van de Voorde

In this paper, results are presented concerning the search to implement Supported Liquid Membranes (SLM) Technology for the recovery of copper, nickel and zinc from electroplating and other effluents to prevent metal waste. A study of the influence of the individual parameters and of their combined effect on mass transfer in small-scale laboratory equipment has been performed, enabling to set forward the appropiate operating conditions for a pilot plant installation. The SLM pilot plant has been tested extensively, including short and long term runs, with real process solutions. It was demonstrated that the SLM technolgy is applicable for solutions containing 800 mg/L of metal ions, but also to the treatment of solutions with low metal content of origin other than plating shops. It was demonstrated by system analysis that the recycled salts are usable to produce metal electrolytes (for example Watt's nickel bath).

Jan 1, 2003

By H. E. Parkinson, Y. P. Chugh

About 90 percent of the coal mined underground in the U.S.A. today is mined by the room-and-pillar system. The productivity of the system dropped from about 14,1t per man-day in 1969 to about 7,3 t per man-day in 1978. Since 1974, the U.S. Department of Energy (formerly the U.S. Bureau of Mines) has been engaged in research to improve the production and productivity of the room-and-pillar system. The effort involves the development of integrated, automated, and remote-controlled equipment and systems including remote-controlled continuous miners, automated miner-bolters, automated extraction systems, continuous haulage systems for use behind miners, and remote-controlled equipment for miners, bolters, and shuttle cars. These systems are discussed briefly, the discussion being related primarily to coal winning, although the concepts could be utilized in room-and-pillar systems in mines other than coal mines.

Jan 1, 1981

By Andrzej M. Wala

The purpose of this paper is to describe a data-acquisition system for mine ventilation surveys that was developed by the author. The system is composed of "off-the- shelf" components integrated through a custom- designed software package to form a user- friendly data acquisition system capable of operating as an unmanned base station or as an operator-triggered roving station. To demonstrate the applicability of the developed system, the author will present data collected during an experimental ventilation survey, which was performed in one of the underground coal mines of eastern Kentucky.

Jan 1, 1993

By Mark S. Stagg, Norman S. Smith, Rolfe E. Otterness, Stephen Rholl

Blast design parameters were studied in an attempt to quantify their relationship to rock fragmentation. The Bureau of Mines conducted a series of 29 reduced-scale shots at the University of Missouri-Rolla's experimental mine with bench size from 40 to 80 inches. Design parameters varied were burden, spacing, explosive diameter and stemming-explosive length. The shots had 3 or 4 blastholes fired at delays of 1-4 ms per foot of burden, based on previous tests that showed hole interaction could improve fragmentation by 12 to 20 percent over single-hole shots or simultaneous firing. All rock, 2000 to 23,000 pounds per shot, was screened and weighed to determine the fragmentation size-weight distribution.

Jan 1, 1991

By Travis Watts, Chris Prater, G. T. Lineberry

Moving overburden at minimal cost is becoming increasingly important to coal mining companies throughout the U.S. The coal market is currently doing well, with an average spot coal price for Central Appalachia product (12,500 Btu, 1.2 SO2) standing at $62.00 for the week ending November 11, 2005, so it is at this time that companies stand to achieve healthy rates of return on their investments. Cast blasting is one method of blasting used effectively by some surface mining operations. This method allows most of the overburden to be removed and placed (cast) directly in the spoil pile by the use of explosive energy. With the proper design of a cast blast, a high percentage of overburden material can be directed into piles without the use of earthmoving equipment, hence increasing production and lowering the cost associated with overburden removal.

Jan 1, 2006