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By K. F. Unrug

The method of coal pillar design involves primarily two aspects, the geometry of the pillar and the strength of the coal. However, the strength of the coal has to be emphasized with respect to the entire pillar dimension rather than isolated strength values of coal samples taken and measured from different locations. The presently applied pillar design systems do not specify clearly what the coal sample strength really represents. The intention of this paper is to introduce the concept of seam strength as opposed to the current practice of using coal strength as a prime design criteria in the formulation of pillar calculations. Seams are most of ten composed of multiple layers of coal, partings, and bone in different configurations, changing within the vertical section of the seam even in relatively close locations. The difference in strength between the weakest and strongest component of the coal seam could be as much as five times or more. An experimental approach based on multiple compressive tests performed on coal samples from the Coalburg and the Warfield seams from Eastern Kentucky was undertaken. The analysis of the results lead to the conclusion that for pillar calculations both the weighted mean of the seam strength and the strength of the weakest stratum should be considered rather than the relatively vague aspect of coal strength The design of pillar dimensions based on the above mentioned aspects should assure a more realistic design performance.

Jan 1, 1985

By P Stewart, S Cowie, A Offer, J Carpenter, E Jones

The Ban Houayxai Gold-Silver Operation is a producing asset for Australian-based copper and gold producer, PanAust Limited. The Operation lies within PanAust’s 2600 square-kilometre Phu Bia Contract Area in northern Laos. Commencing production in 2012, Ban Houayxai is operated by PanAust’s Lao-registered company, Phu Bia Mining. PanAust owns a 90 per cent interest in Phu Bia Mining. The Government of Laos owns the remaining 10 per cent. The Operation mines an intermediate sulphidation epithermal gold-silver deposit and comprises an open-pit feeding ore to a conventional carbon-in-leach process plant. Metallurgical recoveries for gold and silver are approximately 75-85 per cent and 55 per cent respectively. To year-end 2017, the Operation had poured 0.65 million ounces (oz) of gold and 4.7 million oz of silver. The Ban Houayxai Ore Reserve supports a mine life of approximately four years from the end of 2017. The Ban Houayxai deposit is in an early Permian volcano-sedimentary unit which is part of a late Carboniferous to early Permian (310–270 million years ago) volcanic-plutonic sequence of the Truong Son Fold Belt. The deposit formed when hot saline (240–415°C, 2.7–13.0 weight per cent NaCl equivalent) fluids ascended from a geologically fertile island arc porphyry into overlying volcanics along a fault or faults in the early Permian (290–256 million years ago) (Manaka et al, 2014). CITATION: Carpenter, J, Cowie, S, Stewart, P, Jones E, and Offer, A, 2018. Machine learning at a gold-silver mine: a case study from the Ban Houayxai Gold-Silver Operation, in Proceedings Complex Orebodies Conference 2018, pp 82–85 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By L. K. Weaver

The Bureau of Mines has started an engineering study of oil recovery by miscible-phase displacement. As a preliminary part of the investigation a literature and patent study was made to prevent duplication of work already done, to become acquainted with those actively engaged in research of this type, and to learn where the recovery method has been attempted. This bibliography gives results of this study. The bibliography includes 254 references to U.S. and foreign patents and published literature relating to miscible-phase displacement processes of oil recovery. It is divided into the following sections: (1) U.S. patents, (2) foreign patents, (3) literature references, (4) author index, and (5) publication and source reference. The patents and literature references are listed alphabetically by author by intervals of years. References to February 1963 are included.

Jan 1, 1963

During the latter part of 1937 consideration was given to the construction of a; local smelting plant for producing blister copper. Previously copper concentrates had been shipped to the United States of America. The proposition had the advantages of a saving in cost of realization, quicker financial return and reduced dependence on overseas shipping.The smelter was designed by the existing staff, who had difficulty in obtaining data on small plants, particularly on the reverberatory furnace. Construction was started in March, 1938, and the reverberatory was blown in on January 16th, 1939. One roaster had been operating for several weeks prior to this date.While results and operating technique on this new departure in small-scale smelting are barely beyond the experimental stage, it is felt that the experience gained to this time should be recorded to help fill the obvious gap in published information covering plants of this type.At present there are three copper smelters operating in Australia; the other two plants are equipped with blast furnaces.LOCATIONThe new smelter is situated in a position convenient to the concentrator and to the power plant. The site is traversed on two sides by a brick flue, from an old smelter plant, which connects with a 250-ft. stack. This stack and portion of the old flue are used in connection with the...

Jan 1, 1939

By M. C. Bétournay

? Prioritization of this research area identified through a CANMET-MMSL industry survey ? Possible technological breakthrough ? Prioritization of this research area identified through a CANMET-MMSL industry survey ? Possible technological breakthrough Disadvantages ? High cost and long time for equipment development ? Hard rock mining condition limitations ? Size of equipment ? Equipment set-up time, down time ? Performance does not meet financial return targets ? Ground control issues ? Drill and blast retains overall advantage

Feb 1, 2008

By E. G. Joe

"This paper summarizes the main conclusions derived from twenty-two technical presentations made at the 1973 meeting of the Canadian Mineral Processors. Results of two surveys with response from over seventy mines were reported on Canadian milling practice for water re-use and on elimination of cyanide from mill effluents. Water and solution recycle in Canadian mills were detailed for copper, copper-zinc, lead-zinc-copper, nickel-copper, iron and gold mines. Cyanide elimination from mill effluents was reported under current practice and under requirements for further treatment by various other processes. Three recent process equipment entries into Canadian mills have been the on-stream particle analyzer, the new gravity concentration tables for recovery of fine tin and other heavy minerals, and solution-jet slurry equipment for reclaiming ground ore from storage. The principles of operation of this equipment were described along with the practical limitations that were found in their application to mineral processing. Capital costs and milling cost reductions were shown in some operations. Computer control of flotation mill processing was a major item on the program. Four major mining companies outlined their mill process control strategy, computer programs and on-stream analysis equipment. Some capital costs and personnel changes were presented, together with gains in concentrate grade and mill recovery. Recent development work has shown the effect of the type of grinding and of aeration on the recovery of sulphide minerals in flotation. One mining company reported a significant depressing effect on copper sulphide flotation while floating ore ground with mild-steel balls; also, pyrite appeared to be activated in the subsequent zinc flotation step. One company with extensive experience in the application of aeration to copper sulphide flotation showed significant improvement to copper recovery by pre-aeration. Both the effects of grinding and aeration were subject to the constraints of the chemical condition of the ore pulp. The metallurgy of silver recovery by combination grinding - gravity treatment and of gold recovery from a complex gold-sulphide ore were reviewed in two papers on precious metals. The latter paper further described the recovery of gold from the Cottrell collectors and the final disposal of arsenic from the dust collectors."

Jan 1, 1973

By Fredrick M. Ryan

Present indications are that in about 2-3 years phosphor tags will be required in commercial explosives. A permissible 254 run ultraviolet lamp assembly has been developed to permit mine inspectors to detect such phosphor tags and therefore to establish if non-permissible explosives were used. This new lamp is powered by a Miner's cap battery without interference with the normal lighting requirements of the cap lamp battery. It is compact, light, and rugged with very high ultraviolet output.

Jan 1, 1977

By A. Gene Collins

The demand for lithium may increase because of its potential use id lithium batteries and in the generation of electrical power by fusion. Therefore, lithium abundance in some United States oil-field brines was surveyed. Oil-field brines from numerous locations were found to contain more than 100 mg/l lithium and several exceeded 500 mg/l. An area of 25,000 km2, with a reservoir thickness of 60 m, an effective porosity of 5 percent, and a brine with a specific gravity of 1.2 containing 100 mg/l of lithium, contains about 0.75 x 106 tonnes (1 tonne = 1 metric ton = 1,000 kg) of lithium in 7.5 km3 of brine. It is postulated that the brines were enriched in lithium by lithium-rich spring water or lithium leached from volcanic rocks followed by evaporation sequences.

Jan 1, 1978

By J. H. Hollomon, J. C. Fisher

THE fundamental problem concerning the fracture of both crystalline and noncrystalline solids is the divergence between the actual and the theoretically computed fracture stresses; the stress required for fracture, computed from the forces between atoms, is many times that actually observed with commercially available materials. Computations have been made1, 2 indicating that the theoretical fracture stress should be from 100 to 1000 times that actually observed. There are other incidental problems that have arisen, perhaps the most important of which is the problem of size effect often observed in the measurement of the fracture stress of non-metallic solids, such as glass. Another effect concerns the relation between deformation and the stress required for fracture. Experiments recently made with pearlitic steels indicate that the tensile fracture stress increases with increasing tensile deformation and decreases with increasing prior compressive deformation. This marked anisotropy of the effect of deformation on the fracture stress is in contrast with the essential isotropy of the flow stress. Early experiments on rock salt crystals by Joffé, et a13 have illustrated the effect of tensile strain in increasing the tensile stress required for fracture. A consistent theory must be constructed that will explain not only the divergence of the measured fracture stress from the theoretical value, the size effect, and the effect of deformation; but will also explain and predict the effects of combined stress, of temperature, of strain rate, and of metallurgical structure. With respect to this last variable, it has now been relatively well established that the carbide particle is the element of structure controlling the fracture of steels. In steels carbide particles vary in shape from plates to spheroids. It has been found that not only does the magnitude of the fracture stress depend upon the size and shape of these particles, but also its dependence upon strain is affected by changes in shape and size of the particles. The precipitate resulting from the age hardening of duralumin also modifies the fracture stress of this alloy. Nonmetallic inclusions greatly lower the fracture stress of all metals. The magnitude of the lowering depends on the size and shape of the included particles. In glass, the major source of the low fracture stress has been fairly conclusively demonstrated by Griffith4 to arise from real flaws or cracks present in the material. He showed that the stress concentration at the end of a defect was of sufficient magnitude to raise the stress at this location to a value comparable with the theoretical strength of the material. If the cracks were reduced in size, Griffith showed that the observed fracture strength increased by virtue of the decrease in stress concentration. He also pointed out that cracks disposed perpendicularly to the applied tensile stress would be more effective in lowering the fracture

Jan 1, 1947

By Andreas Brandner

"At the beginning of 2007 the Austrian contractor PORR was awarded with remediation works for a 48-km long part of the railway line from Campina to Predeal – part of the Trans European main Corridors TEN-T priority line 22 Bucurest – Brasov, connecting the southeast European countries with the heart of Europe.Due to partly new realignment and change of regular sections as well as protection against rockfall and slope slide a huge bunch of slope stabilization works became necessary, which were awarded to the contractor PORR and their designer IB-Brandner.Following the studies of the tender documents for the planned protection measures responsible managers of PORR decided to propose an alternative protection design by IB- Brandner. Changing the original design a more flexible and environmentally compatible solution consisting of high performance net, soil nailing and rockfall protection systems (fences) was elaborated and adapted to local needs. During design process, several critical areas were identified and additionally taken into account.In the paper examples of the design and erection process show how difficulties in implementation starting with the presentation of the idea continuing to the realization on site were managed and a technically more sophisticated and commercially competitive solution could be delivered to the customer Romanian Railway – case study.The European Commission awarded – following an election process in which all citizens of the EU could join - the remediation project Railway line Campina – Predeal in Romania as the environmentally best EU co-financed infrastructure project. GENERAL PROJECT EVALUATIONDue to original design slope stabilization should be done by concrete slabs fixed with prestressed anchors and shotcrete cover.The area to be secured was limited to a 12-meter strip left and right from the railway track without reference to nature and local needs. Discussions with the client and his designer and rising awareness for the hazards to address took several months. Site visits in Austria to provide insight in the problems of dealing with natural hazards helped to convince the client of the needs and our alternative design."

Jan 1, 2017

By L. W. McKeehan

IT is no longer necessary, if it ever was, for your annual lecturer to apologize for including in his remarks frequent references to the arrange-ment of metal atoms in crystals and for basing his arguments that metals behave as they do upon their crystal structure. Neither will any objec-tion be raised because the large metallic crystals of which we will speak are hard to prepare and of negligible commercial interest. The particular set of physical properties we propose to discuss-ferromagnetic proper-ties-may require more justification. Very few in this audience are primarily, or even remotely, interested in the ferromagnetic behavior of the metals they handle. By no means all of you ever deal, by choice or by necessity, with metals which display any ferromagnetism at all, and even those who study or control ferrous metallurgy must usually depend upon electrical engineers for assistance in ferromagnetic applications. My excuse for talking about such an obvious specialty is, like all Gaul, divided into three parts. In the first place, the members of the com-mittee who select the annual lecturer must wish the speaker to confine himself to matters he has at least thought about before he prepares his speech. In the second place, the study of ferromagnetism in crystals has, as you will soon realize, suffered in the not-too-distant past from inade-quate metallurgy. Further progress probably depends upon proper use being made of the skill and knowledge of some members of the Institute of Metals Division who have not, before today, been asked to think about the problems presented here. Finally, there is at least a sporting chance that the ferromagnetic properties of a few metal crystals will give some insight into the more generally interesting properties which they share with nonferromagnetic metal crystals.

Jan 1, 1934

By P D. Katsabanis

The dynamic tensile strength of geomaterials is known to be highly dependent on the strain rate of the load applied. This is significant in applications where the material is subjected to shock waves and impact loading. This paper proposes the use of a simplified method to determine the dynamic tensile strength of hard brittle rocks using an explosively impacted version of the Hopkinson Pressure Bar. A compressive stress wave was propagated in a sample, representative of the material of interest, by detonating a small charge at one end of a cylindrical sample. The tension wave, generated upon reflection at the free face, causes spalling in brittle materials. Strains at four points in the specimen were continuously measured and the dynamic tensile strength was determined by applying the one-dimensional wave theory.

Jan 1, 2010

The Savage River open cut magnetite mine is located in rugged terrain in densely rain forested northwest Tasmania. The mine and concentrating plant are both in the Savage River valley. Pickand Mather Incorporated (PMI) operated Savage River as an open cut magnetite mine between 1966 and 1996. Acid rock drainage (ARD) was first noted in the last ten years of the operation, leading to elevated concentrations of heavy metals downstream of the mine. When operations ceased in 1996, PMI returned the mine to the Tasmanian Government along with a remediation fund of $11.4 million. At that time, the assessed cost of remediation was in excess of $120 million. As a result of the ongoing ARD contamination and to facilitate both a new operation and effective remediation, Goldamere Pty Ltd negotiated an agreement with the Tasmanian Government in 1996, which resulted in the Goldamere Act and the Goldamere Agreement. The agreement has allowed Australian Bulk Minerals (ABM) to remediate the Savage River mine in conjunction with the Tasmanian Government while re-invigorating a previously closed mine by providing ABM with an indemnity against past pollution. ABM can configure its mine and waste planning activities to maximise remediation benefits without fear of future litigation for past mistakes. The effect to date has been the development of a long-term strategy to remediate the Savage River and short-term remediation works such as water management, which provide benefits to the ecosystem. After five years, the Savage River is no longer significantly impacted by ARD for 30 kilometres downstream and trout are now reported within the reaches of the mining lease. The arrangements between ABM and the Tasmanian Government are an example of a genuine WIN WIN situation where co-operative environmental management of the site results in significant improvements and where the æregulatorÆ and the æminerÆ are working together to achieve mutually beneficial goals. The end result is a significant benefit to Tasmania.

Jan 1, 2003

Spatial information Critical to a project since it underpins: ?Discovery of mineral resources ?Orebodydefinition and technical assessment ?Mine design and planning ?Profitability and project value Data ?Single most import asset. ?Good interpretation of quality data underpins project growth and success. TEAMWORK

May 1, 2002

TO THE BOARD OF DIRECTORS OF AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS Gentlemen:-I have the honor to present the following, report for the calendar year 1920. The activities which seem to call for special comment are: THE NEW FORM OF MAGAZINE MINING AND METALLURGY appeared every month during the calendar year and has been developed until it contains some ten departments. It has brought forth more commendatory letters than have been received at headquarters on any other subject throughout the year. Less than a dozen letters unfavorable to the change have been received, and the indications are that the magazine has met a want deeply felt, especially by members distant from headquarters. The technical papers printed by the Institute are published in abstract in the magazine and opportunity is given to members who desire them to receive full copies of any or all papers published. The Bound Volumes, as usual, contain all the papers in full and discussions thereof. FINANCES The greatly increased cost of paper and printing has put a tremendous burden on the Institute's finances, since the dues of $12 per year are only 20 per cent. greater than the members paid when the Institute was founded forty-nine years ago. This has resulted in a temporary deficit, similar to that encountered by many of our sister engineering societies. The fact that our Institute has lower dues and gives more in the way of publications to its members than any other of the national engineering societies has rendered the situation more difficult for us. MEETINGS The Annual Meeting in New York, the Field Meeting in the Lake Superior District, the meeting of the Petroleum and Gas members at St. Louis, and of the Institute of Metals Division in Columbus, Ohio, have all been described in full in the magazine.

Jan 1, 1925

By J D. Bryant

The Ernest Henry Copper-Gold mine, the third largest copper deposit in Australia, is located 35 km NE of Cloncurry in the Mt Isa-Cloncurry mineral district of NW Queensland. Ernest Henry Mining Pty Ltd (EHM), a wholly owned subsidiary of Xstrata Copper Australia, operates the mine. Approximately 10.2 Mt of ore grading 1.12 per cent Cu and 0.56 g/t Au were processed during the 2001 - 2002 financial year. The Ernest Henry plant produces copper-gold concentrate, which is trucked to Mt Isa for smelting. The Ernest Henry deposit is a member of the diverse Fe-oxide-(Cu-Au) class of deposits. The orebody is hosted within a sequence of moderately SSE-dipping, intensely altered Paleoproterozoic intermediate metavolcanic and metasedimentary rocks. Copper (chalcopyrite)-gold mineralisation occurs mainly within the magnetite-biotite-calcite ¦ pyrite matrix of a 250 m + 300 m pipe-like breccia body. The breccia pipe comprises two anastomosing lenses separated by a lower grade, clast-supported breccia zone. Several anastomosing brittle faults affect the macro-geometry of the orebody. Copper grade is proportional to the degree of matrix support in the breccia. The July 2002 Ore Reserve was 88.7 Mt @ 1.0 per cent Cu and 0.5 g/t Au. Resource estimation at Ernest Henry is based on a large database of predominantly diamond drill hole information. Drill spacing is typically 50 m + 50 m. Ordinary kriging is used to estimate Cu, Au, SG and IST (oxidation indicator) into model parent cells of dimension 20 m E + 20 m N + 16 m RL. The block model is comprised of five geological-geochemical domains represented by 3D wireframe surfaces. Zonal control, where samples and blocks are assigned the same domain number, is used to control grade estimation. The geometry of the domains defines hard grade boundaries across strike and soft boundaries along strike A Deep Drilling Project was initiated in August 2002 with the initial aim of testing the down-plunge extension of the orebody to a vertical depth of over 1 km. The encouraging intersections to date have resulted in a significant increase in the mineÆs open pit Mineral Resource together with the identification of an underground Mineral Resource. Added benefits of the project included an expanded and updated geological legend and an improved understanding of the host geological sequence.

Jan 1, 2003

By T. G. Decker, A. F. Witt, A. M. Gaudin

The historical development of the concept of contact angle hysteresis is reviewed. The measurements of contact angles reported in literature have all been made under static conditions. For the measurement of dynamic advancing and receding contact angles, four methods are described together with an evaluation of their precision. Three of these methods were adapted from devices already used for the measurement of static contact angles. The fourth method uses a new principle and apparatus and is the most accurate. While the relationship between surface tensions and the contact angle was extablished as early as 1805 by T. Young,' it was only in 1890 that the existence of contact angle hysteresis was reported by Lord Rayleigh. His observations, however, remained almost unnoticed. With the invention of froth flotation, the contact angle and its behavior became the subject of investigation. In 1907, L. Sulman and collaborators investigated the cause of discrepancies between recorded values of contact angles. They found that certain variations existed in most cases, but that definite maximum and minimum values of contact angles are obtainable. The difference between the maximum and the minimum contact angle in a given system was termed "hysteresis" by Sulman. First attempts to explain hysteresis were made by E. Edser. In the following years extensive studies of contact angles in various three-phase systems

Jan 1, 1963

By V. Svalbonas, M. Fresko

The present versions of the Welding Codes, such as BS7608, have long been known to be compatible with hand computations of membrane and bending stress, rather than detailed finite element solutions. However, in the last five years, in the mining industry, this incompatibility has been largely ignored, and the code interpretations have been pushed into the realms of ground welds, residual stresses, and even flaw growth. Such techniques have to be recognized as extrapolations not necessarily sanctioned by the original code documents. The safety of such extrapolations, as they are related to grinding mill fatigue design, is investigated herein.

Jan 1, 2002

By Y. Miyabayashi, K. Nishikawa, H. Nagai

JX Nippon Mining & Metals Group recovers valuable metals from end-of-life electronic products in an economical and environmentally-benign way, based on technologies that have been acquired in mining, smelting, and refining operations over time. End-of-life electronic products contain halogens and hydrocarbons. When such materials are treated in the copper smelting process, corrosion of equipment and discoloration of sulfuric acid occur. As a countermeasure to these problems, we have developed pretreatment processes that include an incinerator, exhaust gas washing towers, and a defluorination facility. By implementing these improvements, we have been able to treat a large volume of end-of-life electronic products efficiently in the copper smelting process.

Jan 1, 2014

By J. R. Cole-Baker

An independent technical audit by a consultant is part of the accountability process of publicly owned or publicly quoted companies when raising finance through share issues or loans or the sale of equity, and of banks or development funds when granting loans. Africa is undergoing a renaissance in investment in its mining industry. It is forecast that capital investment, in major mining projects in Africa, will be over US$ 4.4 billion, in the next few years. Most, if not all, of the capital to be raised will require an independent technical audit. The aim of this paper is to assist the management of mining companies seeking finance in appreciating the role of such technical audits. The reasons for such audits, especially to attract international investment, are listed. The role of the audit is explained in assessing the underlying robustness of the company as ?a going concern? and the viability of any ?expansion plans?. Its use is emphasised in establishing the underlying value of the company based on the mine life as supported by the mineral reserves. The independent consultant role is stressed as a representative of the parties in a finance deal who cannot, in practice, carry out their own detailed and specialized technical due diligence. The various components of a typical audit are examined with examples of critical matters which may require resolution. The definitions, which are used commonly in audits, in respect of competence and reserves and resources, as stated by various regulatory bodies, are compared.

Jan 1, 1998