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The January General Meeting of the Institute was held in Kelvin House, Johannesburg, on 15th January, 1969 at 4.30 p.m. Mr R. C. J. Goode (President) was in the Chair. There were also present eighteen Members, including Messrs F. P. Bath, H. Britten, J. K. E. Douglas, P. Lambooy, V. C. Robinson, W. T. Stobart and P. W. J. van Rensburg (Council Members), Messrs J. C. Hall, P. C. Pirow, Dr D. I. Legge, Messrs E. R. Rudolph, H. R. Reid, Dr N. Stutterheim, Messrs B. F. van der Merwe, L. W. P. van den Bosch, D. T. Watt, M. Youngworth and T. Zadkin. Two Associate Members, Dr P. R. Jochens and Mr D. A. Viljoen. Two Students, Messrs R. P. W. Henrard and D. Ossin. Sixteen Visitors, including Messrs I. Barnes, B. F. Bath, S. Botha, P. A. du Plessis, K. Edwards, Dr F. S. Fulton, Messrs H. Grant, B. Havenga, L. Kok, Dr D. Lasar, R. Sandler, C. W. Wolhuter and J. D. Young. Secretary, Mr D. C. Visser. Total present: Forty. MINUTES The President: "May we confirm the minutes of the meeting held on the 20th November, 1968, as published in the December, 1968, issue of the Journal?" Agreed. MEMBERSHIP The President: "I have much pleasure in announcing that the names of the under-mentioned candidates, having been published in accordance with By-Law 5.2.2, Council has elected them to membership of the Institute in the following grades: Members: Basil James Jackson and James Petrie Archibald. Associate Members: Ronald Creasy, Hugh Angus McCallum and John Barton Cunliff. Graduate: Hermanus Isak Johannes van der Merwe. Affiliate: Edgar Ramsay. Student: Petrus Daniel Wolmarans. MEMBERS TRANSFERRED TO A HIGHER GRADE From Affiliate to Associate Member: Neil Bradfield and Mervyn Bayard Allman. "I welcome the newly elected members to the Institute and congratulate those members who have been transferred to a higher grade." (Applause). GENERAL BUSINESS The President: "Are there any matters to raise under this heading? If not, we will proceed to the next item on the agenda which is the presentation of today's paper."

By Driver R. C, Moelle K. H R

This paper is dedicated to the memory of our friend Peter McKenzie who contributed much to the knowledge of the New South Wales Coalfields.ABSTRACTA fossil river system was recently mapped over parts of the Southern Coalfield, N.S.W. This river system occurs in the roof strata of the Bulli Seam. Sandstone of a fluvial nature was deposited in its course. The sandstone exhibits strong sedimentary vectorial properties and has a marked influence on strata-control in colliery workings.The sedimentary features analysed indicate an approximate S200W flow direction. Petrological studies reveal a clastic, well-cemented sedimentologically and structurally anistropic rock type. Washouts have been found and isopach maps of both sandstone and underlying roof-strata have been compiled. Relevant measurements were carried out in existing colliery workings and on bore cores.Optical determinations of feldspars revealed the presence of plagiocIase feldspars with few exceptions. Most of the feldspars are altered to clay minerals. It was found that a geographical trend exists in the distribution of feldspars, with more basic plagioclase in the northern part of the field.The source area of the fluvial sandstone lies to the north of the Southern Coalfield.Petrofabric analyses were done on several specimens of the fluvial sandstone. In the vicinity of major disturbances, penetrative fabrics were discovered.Calcites (e, 0112), micas (001), and quartz (crystalIo graphic c) show preferred orientations.

Jan 1, 1967

By C. K. Man

Coal dust explosions in underground coal mines are prevented by generous application of rock dust (usually limestone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents flame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of explosion experiments using various coal dust and limestone rock dust mixes have been carried out at the Lake Lynn Experimental Mine (LLEM). These were conducted in a single entry of about 1600 ft (488m) in length and initiated with a methane gas explosion. A consistent set of post-explosion floor dust samples were taken along the entry after each test. These dust samples have been analyzed in the laboratory using thermogravimetric analysis (TGA) and solubility to determine how the limestone rock dust behaved during the coal dust / rock dust explosions. The preliminary results are reported in this paper and indicate that the chemistry of limestone plays an important role in its capacity to inhibit coal dust explosions. The results also show that it may be possible to estimate the intensity of the explosion using these conventional methods of analysis. Disclaimer: The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.

Jan 1, 2009

The sulphide ores of the principal lodes of the Boulder Mines are mainly composed of a schistose guess with a varying proportion of silica and lime, containing tellurides of gold, silver and mercury, associated with iron pyrites. It is a great difficultyto obtain pure and homogeneous samples of the tellurides for analysis, and from a number of tests made with excellent specimens it was found hardly possible to procure two to agree in analysis, the precious metals being found to be combinedwith tellurium in most varying proportions indeed, a close inspection of a partially crushed specimen will reveal, even to the naked eye, the various shades of colour characteristic...

Jan 1, 1901

Standards And Laboratory Monitoring In Gold Assay Key Components Of Best Practice

Jan 1, 2005

By B. J. Kloppers, J. V. Z. Visser, C. J. Horn

"The long-term plan (LTP) in a mineral resource company is defined by the quality of the mineral resource and represents the result of a series of trade-offs to fulfil internal organizational as well as external business and legislative requirements, ensuring ultimate delivery on the defined organizational strategy.The LTP should as a whole align to a coherent and well-defined organizational strategy, working towards a clearly defined objective while still allowing a tactical response to short-term requirements of the organization. The ability to respond tactically to changes in environment, like the unprecedented five-month strike in 2014 on the platinum belt following the 2012 Marikana incident, is a measure of the flexibility of the plan given the agreed strategy.This paper describes the Lonmin process of linking company strategy with long-term planning, tactical planning, and the execution of the plan through an annual planning cycle to maximize organizational flexibility. This flexibility enables mining companies to respond to the many internal and external forces that impact on both strategy formulation and delivery of results that meet shareholder expectations."

Jan 1, 2015

By James C. Barker

In 1981 and 1985-1986, the Bureau of Mines conducted orientation studies of marine placer platinum-group metals (PGM). PGM are derived from the Goodnews Bay ultramafic complex and magnetic surveys show that the complex extends offshore at least four mi. The present seafloor was an emergent foreland as recently as 8000 years ago. High-energy ocean processes are transporting and depositing sediment such that PGM-bearing materials are reworked and later masked by barren littoral drift. Exploration targets include 1) placers formed since present transgression began, and 2) ancient marine and drowned fluvial deposits. Additionally, there is evidence of PGM solution transport and accretion. At least minor values of PGM in Recent lag-type placers and possible submarine strands are concentrated along an offshore scarp incised through glacial deposits into the preglacial surface between Flat Cape and Red Mountain. Other Recent PGM-bearing features include Flat Cape shoal, Chagvan Bay, Salmon River delta, and modern beaches. Ancient placers include possible N-S fluvial systems 2 to 3 mi offshore, a nearshore scarp 50 ft below sea level, and strands adjacent to projected ultramafic bedrock slopes. The existance of ancient placers is dependent on depth of glacial erosion. SEM studies show PGM are principally isoferroplatinum and osmiridium, with minor sperrylite, moncheite, and platiniridium. Gold is a co-product, and concentrates comprise chromite, ilmenite, and magnetite. Beneficiation tests successfully concentrated precious metals from natural blacksand accumulations, but failed to concentrate low-grade lag gravels.

Jan 1, 2011

A dedicated tunnel construction version of the Caterpillar 328D LCR compact radius excavator is proving highly productive on the A9 Autoroute construction project near Visp, in Switzerland. It is the first machine of its kind to operate on a Swiss contract and uses a special dedicated front attachment designed and constructed by German Caterpillar dealer Zeppelin. The machine offers a powerful, stable and compact solution for tunneling contractors. A rear overhang of just 305 mm (12 in.) provides a tail swing radius of just 1.9 m (6.2 ft). The 328D LCR is ideal for the restricted working areas within a tunnel construction site. The machine is equipped with the wide tracks from the 330D L conventional crawler excavator, ensuring maximum stability when operating. In addition, the boom mounting has been moved further toward the center of the machine for the tunnel model, creating an increased lift capacity over the front end compared with a standard 325D L. The boom itself features a robust box section construction, with high-strength steels, additional supporting struts and reinforced bearings for maximum durability. All pins have hard-chromium plating for optimum protection against wear. Stick digging force is a powerful 134 kN, with up to 212 kN of bucket digging force available, for maximum penetration in blasted material. The 328D LCR is also equipped with a heavy-duty dozer blade as standard. This ensures outstanding stability when working and providing a useful secondary tool for clearing and leveling within the jobsite. Two 45° tilting mechanisms in the boom construction, allow the boom to be swung to 45° on either side of the machine. So the specially designed attachment linkage provides increased rollback for access to the roof of the tunnel. A Caterpillar CW45S mechanical quick-coupler allows rapid changes between specialist tunneling attachments, standard Caterpillar buckets and a range of Caterpillar work tools. The machine is powered by a Caterpillar C7 diesel engine. This six-cylinder EU Stage IIIA diesel motor [ ] offers 8 percent more power than its predecessor, with 140 kW (190 hp) available at just 1,800 rpm. Caterpillar?s ACERT combustion technology results in lower fuel consumption and reduced exhaust emissions. However, the tunnel machine is also equipped with a diesel particulate filter as standard, to further cut exhaust gases within the tunnel working. The 328D LCR is designed for use in transport tunnels of 6.8 m (22.3 ft) in height. With the tunneling boom in place, the machine has an operating weight of 42,540 kg (93,783 lbs), yet retains a transport height with the tunnel boom of just 3.9 m (12.8 ft). Transport width with 600 mm (23.6 in.) track shoes, is just 3.2 m (10.5 ft). On the A9 tunnel contract, the machine is being used by a consortium of Swiss and Austrian companies working for the canton of Valais? Routes Nationals Construction (RNC) department. The 31.8-km (19.7-mile) A9 Autoroute construction project will connect Sierre in the west and the town of Brig to the east. The tunnel that is bypassing the town of Visp is just one of a number along the mountainous route.

Jan 1, 2009

By E. Z. Manos

The Detroit salt mine is operated by the Detroit Salt Co. It is one of the oldest underground room-and-pillar mines in the United States still in production. Mining at the Detroit salt mine began in 1906 with the sinking of the No. 1 shaft. Mining continued through the years, becoming progressively more modern in its equipment and techniques, until it was closed in 1983. In 1997, after a period of care and maintenance, the newly formed Detroit Salt Co. decided to reopen the mine. Upon completion of an extensive rehabilitation program, salt production resumed in 1998. Production currently continues at a rate of 910kt/a (1 million stpy). To date, the Detroit salt mine has mined more than 45 Mt (50 million st).This mine is unique because it lies under a heavily urbanized area within metropolitan Detroit. The mine and its history make a good case study for the continuing coexistence between the mining industry and its environs.

Jan 1, 2003

By Hamid-Reza Manouchehri

Mining & Sustainability? A Paradox?! ? Production: gradually or exponentially increasing (giant mining) ? Ore Grades: gradually declining, ? Open Cut Mining: now widespread, likely to be sustained in the future though the long-term is hard to predict as new mineral deposits are likely to be deeper ? Waste Rock / Overburden: increasing rapidly, likely to be sustained in the future and closely linked to open cut mining, especially for coal and base metals ? Economic Resources: commonly increasing but some remain stable or gradually declining, future is linked closely to exploration, technology and economics; Increasing population, changing life style and technology development, ultimately result in sustainability in mining industry to hang in the balance and continue.

May 1, 2013

By K. P. Black, G. W. Sevick, D. E. Hockley, K. S. Sexsmith, J. T. Chapman

Mineralogical analyses of carbonates in depyritized tailings and pyrite concentrate (from depyritization of the tailings) were completed as part of the tailings characterization for the Crandon Project, a massive sulfide deposit in northeastern Wisconsin. The mineralogical study was designed to determine the proportion of calcium and magnesium carbonates, and therefore the effective buffering capacity of carbonates in the tailings. The depyritized tailings are net acid consuming and will be stored in a surface tailings management area. The pyrite concentrate is net acid generating and will be used as backfill in the underground mine workings. The majority of carbonates in the depyritized tailings were ferroan dolomite containing 10 to 15% iron (by weight) and lesser amounts of siderite and magnesian siderite. The proportion of calcium and magnesium-rich carbonates corresponds to several independent tests of carbonate neutralization potential (CO3-NP) availability. The pyrite concentrate had less CO3-NP, indicating segregation of the carbonates during pyrite flotation. These carbonates reported higher iron contents, consistent with the relatively lower availability of CO3-NP in the pyrite concentrate.

Jan 1, 2002

By David V. Lewin

Heavy structures in central Cleveland, Ohio, are supported on raft foundations, driven piles, or caissons. Settlements can be predicted and structures are designed to accommodate such settlements. On one project the settlements were not provided for in the design of the structure. Soils are sands, silts, and varved clays to shale. A rift in a central area is 600 feet deep. Solutions to problems, and results, are detailed.

Jan 1, 1985

By John E. Wiegand

This study will discuss the AMAX Coal Co., Penndiana Pipeline Project, which was conducted in conjunction with the following parties: AMAX Coal Industries, (U.S.B.O.M.) United States Bureau of Mines, (I.D.O.R.) Indiana Division of Reclamation, Ohio Valley Pipeline, Inc., New Mexico Tech, and ourselves, VIBRONICS, INC., Evansville, Indiana. The purpose of this study was to find a safe vibration level for active gas transmission pipelines near surface coal operations.

Jan 1, 1994

By John J. Sammarco

Abstract- Emergency shutdown systems (ESDs) for mining machinery provide critical functions to safeguard miners. Traditionally, ESDs were realized with simple hardwired circuits; today, there is a growing trend to use programmable electronic technology such as programmable logic controllers (PLCs). This paper describes an analytical study to quantify the safety integrity of a PLC-based ESD and a hardwired ESD. The safety integrity level of each design approach was determined by quantifying the average probability of failure on demand (PFDavg) as described by the recommendations for programmable electronic mining systems published by NIOSH and the IEC 61508 international standard. The safety analyses addressed system architecture, hardware failure probability, proof test interval, diagnostic coverage, and human error probability. The results indicated that a same level of safety, safety integrity level 3 (SIL 3), could be attained when evaluating random hardware failures. Neither approach could attain SIL 3 if manual activation was used. Human error was the limiting factor where, using human reliability analysis, PFDavg < 1 x 10-1; thus, the ESD does not meet SIL 1. It is apparent that automatic verses human¬activation of the ESD is a very important safety consideration. Manually actuated ESDs can only achieve SIL 1 regardless of the technology; therefore, additional independent safety layers of protection are needed to exceed SIL 1. Secondly, it is apparent that the technology choice is very important. The PLC-based ESD was much simpler to design and to validate safety1.

Jan 1, 2007

By Julie Dénommé

Today few in business would argue with the idea that we are living in a world that is Volatile, Uncertain, Complex, and Ambiguous. Coined VUCA by the US Army War College, these four words define the ?turbulence? and ?continuous white water? that the business literature has been documenting for the last decade. This VUCA world became even more relevant to business in 2007 when the Institute for the Future fellow Bob Johansen published the idea of transforming VUCA into Vision, Understanding, Clarity, and Agility. We call this VUCA Prime (VUCA&apos;), and place an infinity loop (8) between them to show their dynamic interaction. This paper presents an exploration of the impact of VUCA 8 VUCA&apos; on business and the conditions under which these dynamic forces help to successfully navigate change.

Oct 1, 2010

By Steven C. Borell

For more than a decade, changes have occurred each year that have improved the regulatory and business climate for mining in Alaska. These changes have taken place during Republican and Democratic governorships as well as when the state House of Representatives and Senate were controlled by either party. During some years, the changes have been relatively minor. In others, including the 2003 legislative session, the changes could only be characterized as massive. These improvements have encouraged exploration. This, in turn, has resulted in some major new discoveries. But Alaska is essentially unexplored and tremendous opportunities remain.

Jan 1, 2004

By George Anagnostou

Time-dependent ground behavior may have important implications for the construction process or the life of a tunnel. The paper gives a concise overview of the influence of time on the deformations and the stability of underground openings, including topics such as face stability in soft ground or the time-development of pressure or deformations in squeezing or swelling rock. While keeping in mind practical questions of tunnel engineering, emphasis is placed on understanding the observed time-dependency, on the underlying mechanisms (such as pore water pressure dissipation or chemical processes) as well as on the respective inherent prediction-uncertainties and design-uncertainties.

Jan 1, 2007

By W. W. Adams

"The eighth National Safety Competition, that for 1932, conducted by the United States Bureau of Mines, was participated in by 322 mines and quarries operating in 34 States. Tables 2 to 6 show the relative standing of the various plants. Bronze trophies, known as the 'Sentinels of Safety,' which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines, were awarded to five companies, each company having established the best accident-prevention record within one of the five classes into which all companies were divided, - namely, anthracite-mining companies, bituminous-coal-mining companies, metal-mining companies, operators of nonmetallic-mineral mines other than coal mines, and quarries or open-cut mines. The trophies are awarded for one year and are then transferred to the winners of the succeeding year's contest.The trophy for bituminous-coal mines, which has been in New Mexico for the past year, was won by a mine in West Virginia. The metal-mine trophy goes to New York State for the first time in the history of the contest. Previously it had been won by mines in Minnesota, Michigan, Kansas, and Oklahoma. The trophy for nonmetal mines remains for another year at Retsof, N. Y.; that for quarries and open-cut mines is transferred to a quarry in Michigan. The trophy for anthracite mines, of course, remains in Pennsylvania, as all anthracite mines in the contest are in that State.In determining the relative standing of the various companies enrolled in the competition, all mines and quarries were graded according to their accident-severity rates, - that is, according to the number of days of disability of employees on account of accidents in proportion to the number of man-hours of work done by all employees at the plant. Reports of accidents and of man-hours worked were furnished by the companies to the Bureau of Mines. These reports were carefully examined and classified to insure uniform weighting of accidents according to the number of days of disability to be charged and to insure uniformity of methods of calculating the accident-severity rates for the various mines and quarries. When the relative standing of all plants had been determined in this way, a summary of the records of the companies having the lowest accident-severity rates in their respective groups was sent to the members of a committee of award for examination in accordance with the rules governing the safety contest. The members of the committee of award were W. H. Cameron, managing director of the National Safety Council; William Green, president of the American Federation of Labor; James F. Callbreath, secretary of the American Mining Congress; T. T. Read, Vinton professor of mining engineering of Columbia University; C. B. Huntress, executive secretary of the National Coal Association; A. J. R. Curtis, assistant to the general manager of the Portland Cement Association; and A. T. Goldbeck, director of the bureau of engineering of the National Crushed Stone Association. When two or more mines within the same group operated without an accident during the year, the contest rules provided that the trophy for the group should be awarded to the plant whose record showed the largest number of man-hours worked."

Jul 1, 1933

By C. Mosoane

ERPM was formed in 1893 and as a result of its age, a large volume of data exists in a paper-based format and it was decided to electronically capture data in one of two critical mining areas?namely at Far East Vertical (FEV) Shaft Area (Lower Areas) and Hercules Shaft Area (Upper Areas). The life of mine is dependent on tonnage and grade from these areas. Geostatistical evaluation of the gold reserves has been applied on an ad hoc basis in the Hercules Shaft Area and on a continuous basis in the FEV area. This is the first evaluation using geostatistics that was performed on the Upper Areas. This paper is based on the premise that regardless of cut-off grades, geostatistical estimation (kriging) estimates and locates reserves better than ?traditional? methods e.g. polygonal method, inverse squared distance method and it endeavours to estimate and locate the high grade reserves in the Main Reef Leader of Upper Areas.

Jan 1, 2003

When the first rush of miners took place on the Molyneux River, in the Dunstan Gorge, the gold was won by means of cradling the gravel, which was shovelled from the various beaches and crevices in the rock-bound sides of the river.The above method of winning the gold was only practicable when the beaches were not covered with water, hence the work was usually carried on during the winter months, the ordinary level of the river during spring and summer months being some ten or twelve feet above winter level. The melting of the spow in the Lakes water-shed being responsible for the high summer level of the river.As the available beaches were worked out, other methods of winning the gold were proposed and worked with more or less successful results the first advance being to work the bed of the river by means of a spoon dredge. The spoon was made with a round lip or ring of iron, having a steel cutting edge on one half of the circumference, at the opposite side a socket being forged to take a long spar or boom, which was securely fitted thereto. At intervals round the hoop, half-inch holes were bored to enable. a bullock-hide bag to be laced on to same. The spoon was worked from a pontoon which carried a crab winch, tackles and the necessary washing appliances to treat the washdirt lifted. In starting to dredge, a tackle was attached to near the upper end of the boom, and a line or chain was carried over a cat head from the crab winch...

Jan 1, 1901