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Various aspects of the history of mining at The Zinc Corporation, Limited (ZC) and New Broken Hill Consolidated Limited (NHHC) are examined. There are some discussions about the various methods used to mine the pillars left after the primary mining operations, with an enphasis being placed on the more modern pillar mining methods. Some new pillar mining proposals are presented. INTRODUCTION In the past, pillar reserves at ZC/NBHC have been scheduled for mining by labour intensive and high unit cost mining methods. These methods include both undercut and fill and overhand square set timber stoping. Recent technological advances in large diameter longhole drilling and high charge density explosives have culminated in the mechanised Vertical Crater Retreat (VCR) mining method and this method has been successfully used for the extraction of two pillars at NBHC and more stopes are planned. However the use of VCR methods for mining pillars at ZC/NBHC is restricted to approximately 50 per cent of the total pillar reserves and it appears that high cost methods will be needed to mine the remaining Pillars.

Jan 1, 1983

By T. A. O’Hara

SINCE May 1948, when tungsten carbide bits were introduced at the Flin Flon mine, they have been popular with the miners because of their fast drilling speed and low gage loss. The high cost of commercial carbide bits and tipped drill steel, however, prevented their use except for the hardest rock. In an effort to extend the use of tungsten carbide on a basis economically competitive with detachable steel bits, experimental work was begun in 1950 to test the feasibility of making tungsten carbide tipped drill steel in the mine drill steel shop. This work showed that tipped drill steel could be made locally at less than half the cost of the commercial product. The performance of the local tipped drill steel was comparable to that obtained with commercial carbide bits and tipped drill steel and the cost per foot drilled was much lower.

Jan 3, 1954

By S. G. Malghan

Flotation is the primary method for copper minerals separation from porphyry ores. The need to process difficult-to--float porphyry copper ores presents challenges to engineers and scientists in several areas. This paper is concerned with summarizing generalized problems faced in processing porphyry ores and treatment methods to overcome them. Though some of the problems are interrelated, they are classified into three broad categories. The case studies of some of the successful applications of innovative methods to solve problems related to ore mineralogy, metallurgical aspects of ore treatment, and process variables show that quite often the problems are solvable by a judicious choice of flotation variables.

Jan 1, 1987

By H. Herbert Hughes

In the years following World War II, L. de Roll S.A., Zurich, Switzerland, perfected its vertical kiln. De Roll first became interested in cement-manufacturing equipment in 1947, not only kilns but also the crushing, grinding, and handling equipment required for a complete cement plant. The parent company, Louis de Roll Iron Works, S.A., Gerlafingen, Switzerland, was founded in 1804. In its six plants, and with its associated companies, de Roll manufactures and installs equipment for a wide variety of industries-chemical and metallurgical operations, fats and oils plants, and municipal refuse incinerators and sewage disposal installations. Vertical shaft kilns, of course, are as old as Portland cement itself. Their fuel economy has long been recognized, particularly in Europe where fuel costs are high. But the disadvantages of old-type shaft kilns have been the lack of consistent quality of the clinker, the small capacity, and the relatively high labor costs.

Dec 1, 1956

By Sneyd R. J, Walton M. C

In early 1987 Minproc acquired a license from the inventor to engineer and construct acid plants incorporating the Fattinger technology. The process offers a simple and reliable method of producing sulphuric acid from metallurgical off gases at significantly lower capital and operating costs than the more familiar contact process. The process also offers the simultaneous production of nitric acid, if the NOx content of the off gases is high enough. A development of this latter process has other applications within the minerals industry, particularly in conjunction with refractory gold ore preoxidation.

Jan 1, 1989

The Bellambi Coal Company Limited com menced longwall mining at South Bulli Colliery in 1965. At present it operates three long- wall units in two seams. Although results to date have been less successful than planned, it is apparent that this type of mining has tremendous potential in the particular conditions at South Bulli. Massive sandstone strata above the Bulli seam is the controlling influence on face conditions. The earliest equipment proved to be inadequate and the Company has progress- ively replaced and upgraded the roof supports and ancillary equipment so that the present units are capable of producing high and consistent outputs.

Jan 1, 1976

TO THE BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN : Submitted herewith are the report of the Treasurer for the year 1944 and reports for the same year of the following standing committees: Membership, Ad- missions, Papers and Publications, MIN- ING AND METALLURGY (Magazine), and Library. To these reports you are referred for additional details.

Jan 1, 1946

By J. B. Hiskey, S. Chander, B. J. Scheiner

The use of selected iron complexing agents in preventing or ameliorating acid mine drainage was investigated. The experiments were conducted in weathering columns using refuse samples from a coal cleaning plant. It was observed that the treatment with iron complexing agents significantly altered the rate of oxidation. Some of the reagents tested reduced the rate of oxidation whereas the others even enhanced it. The results showed that a commercial reagent containing oleyl imidazoline was most effective in retarding the oxidation rate. In addition, a simple treatment with this reagent substantially decreased the rate of oxidation of pyrite in a column that was generating acid at a high rate. The effect of this reagent on the surface properties of pyrite was studied by cyclic voltammetry and zeta potential measurements. The decrease in the rate of oxidation resulted from suppression of both anodic and cathodic reactions at the surface of pyrite.

Jan 1, 1993

By Juan Eduardo Barrera

SUNNARY AND CONCLUSIONS Argentina presents to the foreign and local investors a mineral wealth that is largely unexplored, untested, underdeveloped and therefore incompletely evaluated. In view of the above, the new administration of President Raul Alfonsin through its Department of nines has designed and implemented a strategy ( Plan de Expansión Ninera P.E.M.), whose main objective aims at improving the "investment climate" in the sector. It is the Government's basic intention to apply the Mining Promotion Law with responsibility but with generosity to encourage the attraction of investment (local and foreign) to the sector. The establishment of a Data Bank system to evaluate possible new potential ore mining developments will help to connect the owners of potential projects with investors outside the sector. Argentina has an interesting gold ore potential. Estimated reserves of individual projects already known amount to almost 300 tonnes of gold for potential production. The government strongly believes and present information indicates that more systematic exploration has to be undertaken in the Jurassic areas that almost cover the whole of Patagonia. Two recent gold discoveries (Angela in the Chubut province, and Cerro Vanguardia in Santa Cruz province) indicate the potential of this area.

Jan 1, 1988

By Gerald H. Luttrell, Rick Q. Honaker

A coal preparation plant incorporates a variety of solid-solid separation processes that operate in relatively independent parallel circuits. Studies have shown that total plant performance can be optimized by selecting circuit cutpoints that maximize total clean coal yield irrespective of the performance of individual circuits. Although the optimum cutpoints can be determined using simulation programs, these mathematical routines require detailed washability data and empirical partition information that is not often available to plant operators. In addition, routine fluctuations in the washability characteristics of the plant feed make this approach impractical to implement in industrial facilities. As an alternative, practical optimization criteria can be developed for plant operators through a fundamental understanding of scientific principles involved in coal cleaning operations. This article provides an overview of the most important optimization criteria and presents several industrial case studies that illustrate the financial benefits of this practical approach m plant optimization.

Jan 1, 2005

By Noel N. Moebs

The Bureau of Mines measured surface subsidence above four small coal mine room-and-pillar sections in southwestern Pennsylvania, to obtain preliminary information on the magnitude and character of selected parameters, such as angle of draw and maximum subsidence, which are essential to the development of subsidence prediction methods. Data varied widely at the four sites; this is attributed to local geologic and mining conditions. Surface deformation at each site was of a magnitude normally associated with severe structural damage.

Jan 1, 1982

Basic premises for evaluating special characteristics of gold-bearing porphyry metal systems stem from their contrasts with properties of the class as a whole. Included features are differences in geologic, thus tectonic, environments, subtle but real differences in the proportions of accessory metals Mo-Ag-Au that are regionally and within some regions, tempo-rally distinct, contrasts in the Ag:Au ratios, petrological-geo-chemical as well as isotopic differences between intrusive suites, the age and nature of host terranes, contrasts in alter-ation style, and zoning variations of mineralogical and physical properties of rocks. These properties are linked in various ways in different regions and suggest that in large gold-bearing systems where gold may be uniformly distributed, environ-ments of emplacement, and compositions or sources of igneous "progenitors" may dominate in importance over processes, and that systems in which gold is zoned are processes-dominant.

Jan 1, 1990

By McCarthy P. L

With production at Olympic Dam scheduled to commence in June 1988, it has been necessary to install a complete underground ore handling system capable of removing two million tonnes of material annually from the mine. The system comprises mucking from stope drawpoints, truck haulage to underground storage, primary crushing, conveying and hoisting. On the surface, material is conveyed to stockpiles at the Metallurgical Plant. Mining of the numerous special excavations within the system was incorporated into the mine's ongoing development program prior to the underground construction phase. Utilisation of a decline from the surface enabled versatile construction equipment to operate at the underground sites as well as simplifying the transportation and delivery of construction Materials.

Jan 1, 1988

By Robert Carlson, Hugh McMillan

During 1967, the Metropolitan Sanitary District of Greater Chicago adopted a policy of land application as a method of using the solids produced in the wastewater treatment process. Research by the Agronomy Department of the University of Illinois, several demonstrations on farm land, reclamation of acid strip-mine spoils, fertilizing a land fill, and reclamation of an alkaline sand waste pit showed the value of using wastewater solids to reclaim marginal and submarginal lands. To launch the Solids-On-Land Program, 10,000 acres of land in Fulton County, Ill., was purchased, part of it previously strip-mined for coal. The Sanitary District initiated a water monitoring program, constructed holding basins, leveled the land, awarded a liquid fertilizer transportation contract, installed a distribution end application system, and began application and crop production. During 1972, the Sanitary District completed the first year of application and harvested the first corn crop. The corn yielded 60 bu per acre while the previous year in a demonstration field it yielded 56 and 13 bu per acre, respectively, on treated and untreated strip-mined land.

Jan 1, 1976

By John E. Udd

Introduction During the very long period in which man has mined minerals from the crust of the earth, falls of ground and collapes of under- ground workings have been the causes of a significant part of those accidents which have resulted in either death or in injury. At present, because of improvements in the approaches to the design of underground structures, in equipment, and in attitudes towards accident prevention, the proportion of accidents due to instability of rock is probably far less than it was historically. Nonetheless, in spite of the many advances which have been made, instabilities still account for about one-quarter of all fatalities, and one-tenth of all of the injuries, in the minerals industry. The means must be found whereby both the numbers of accidents and the accident rates due to falls of ground can be reduced to the lowest levels possible. At the outset it should be stated that, short of suspension of all mining activity, it will probably never be possible for us to eliminate accidents completely. Most human enterprise involves unknowns and risks, and mining is no exception. A certain number of accidents, then, must be viewed as the inevitable consequence of our attempting to work with unknowns and to make decisions that involve uncertainties. However, in retrospect, many instabilities can be attributed to factors which could have been within our control. The preventable accident must be eliminated. It should be our goal that we make every effort to direct our skills and technology to the creation of a safer working environment and should be constantly striving to

Jan 1, 1983

By J R. Kyle

The Deep Mill Level Zone (DMLZ) skarn Cu-Au deposit is the deepest explored part of the Ertsberg East Skarn System extending from the surface at 4200 m elevation to the DMLZ at 2900 to 2600 m. The DMLZ is hosted in an upper Cretaceous to lower Tertiary siliciclastic and carbonate succession adjacent to the 3 Ma Ertsberg pluton. Much of the DMLZ ore is hosted by mixed assemblages of siliciclastic and dolomitised carbonate strata that have been altered to Mg-rich skarn assemblages. Unaltered equivalent strata from a 300 m cored interval in the Yellow Valley Syncline were characterised petrographically and representative samples were analysed for major element compositions. These stratigraphic and chemical units are interpreted to be responsible for the varying skarn lithologies within the DMLZ. The dominant prograde skarn assemblages are controlled by protolith composition, notably the relative abundance of quartz, dolomite, and calcite within the protolith. Models based on isochemical metamorphism of mixed assemblages of quartz and dolomite suggest that the formation of the forsterite-diopside dominant skarn assemblages resulted in the greatest amount of pore space increase. DMLZ Cu-Au concentrations were locally controlled by host lithology, with structural features providing fluid pathways that focused the mineralising fluids. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By C Yates, S Jobling, Z Y. Yang

The current trend in the UK towards the adoption of retreat longwall mining methods and the associated rapid development of the access drivages have exacerbated the environmental conditions experienced within these workings. There is a recognised need to improve the efficiency of the design and operation of mine ventilation systems in order to maintain an adequate environment and climate within these workings. Any improvement achieved in the quality, quantity and control of the delivered ventilation will assist in the provision of improved gas and dust dilution and climatic control. The paper presents an analysis of the psychrometric data recorded during the execution of a series of comprehensive climatic surveys conducted within two representative deep underground UK coal workings. The surveys were performed across two high production retreat longwall districts within UK Coal Ltd collieries. The surveys employed intrinsically safe psychrometric transducers and digital data-loggers to collect a continuous record of the mine climate over designated weekday production and weekend non-production periods. The transducers and data-logging units are capable of simultaneously measuring and digitally recording changes in the dry bulb temperature and the relative humidity at regular time intervals for extended periods of time.

Jan 1, 2005

By Ernest Darby

WHEN bronze is melted in open-flame furnaces a considerable amount of slag is formed during the melting operation. This slag may be incidental to the melting practice or it may be formed intentionally by slag-forming constituents added to the furnace charge to provide a covering for the melted metal. When this slag is removed from the furnace, it contains, in addition to the free metal carried with it by the skimming operation, a considerable amount of metal as oxide either combined or mechanically mixed with it. By the usual crushing and washing methods this metallic oxide generally goes to the tailings pile, so diluted by other foundry waste that its recovery is economically impossible. If this furnace slag is not mixed with other foundry waste, practically all of the metal oxide as well as the free metal may be recovered by some form of smelting operation. The first side of the problem to be considered is the amount of slag produced. It may not be true that the majority of foundries have no record of the amount of slag made, but it is certainly true that a very great many either have no record or pay little attention to it. Usually the collection of furnace slag for one normal week's run will be sufficient to determine the advisability of its being handled in a different manner from the crushing and concentrating generally employed. If a large representative sample of the accumulation is crushed and concentrated and the recovery compared with the results of a careful assay, it will be found that a large percentage of the total metal content was lost in the washing process. The percentage of loss will be greater than the metallic oxide content, as some free metal in extremely fine particles always is carried away in grains of slag: From such a comparison, it may be determined whether or not the slag should be melted, sold or treated as before. An example of an actual test of this kind is given below.

Jan 1, 1928

By Seymour D

The disagregation and privatisation of the mining and power gene ration operations of the former State Electricity Commission of Victoria has being taking place over the past five years. This has transformed the service provision to the new organisations and has resulted in major change to the working lives and professional relationships of thousands of Australians. The authors wish to take this opportunity to explore the issues arising as the program of privatisation of public assets continues. Changes within the workplace which resulted from the outsourcing of the 'investigation and design' functions and more lately as a result of privatisation of the operating, generating and distribution businesses are discussed. The responsibility of managers retaining the services of design engineers has changed. There is an added responsibility of contract administration and an increased focus on intellectual property and strategic issues. The way in which the sectors are adapting is discussed and future directions are explored. We welcome this opportunity to explore the changes in professional life which have taken place over the last five years in the Latrobe Valley Power industry. Engineers and earth scientists have a pivotal role in the continuing successful operation of the three Latrobe Valley Mines of the generation companies. The Mines' collectively excavate annually over 13 million cubic metres of overburden and 48 million tonnes of coal for delivery to mine-mouth power stations and for briquette manufacture.

Jan 1, 1997

By Marshall GA

Structural fatigue damage of haul truck frames is a costly problem associated with the operation of large mine haul trucks. A monitoring programme is described which has been instigated to measure stresses in the frames of haul trucks under actual mine operating conditions. The instrumentation used and methodology employed in the computer analysis of the results is briefly described. The results of the monitoring programmes are reviewed, and the effects of various factors affecting structural fatigue damage of three common types of rear dump truck are considered. Factors discussed include the effects of haul route features (for example shovel, dump and crusher areas); the effect of operations such as turning, braking, loading and dumping; the influence of payload; the effects of malfunctions in suspensions; and the influence of haul route surface quality. It is shown that with respect to payload, while structural fatigue damage is increased with payload, the structural damage per unit of payload does not change significantly for moderate increases in payload above the nominal value. Finally, on the basis of these results, recommendations are made for haul route design and operational practices which will increase the structural fatigue life of haul truck frames.

Jan 1, 1986