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By Persifor Frazer

CONTENTS. PAGE 1. Committee House of Commons Report (1843).......521 2. Clark (1880).............521 3. Schröder and Schertel (1884).... . 521 4. Committee House of Lords Report (1887).......523 5. Vita (1890).............524 6. Irvine (1890-1)............524 i. Cramer (1891)............525 8. Bailey. Cohen. Tatham and Hartog (1891))......525 9. Morrison (1891)............525 10. Brunner (1891)............525 11. Bell (1892).............585 12. Oades (1892).............526 12a. Purcell (1892)............526 13. Sennett (1892)............526 14. Bulier (1892).............526 1.7. Wiesner (1892))...........526 16. Thomson (1892)............530 17. Fletcher (1892)............530 18. Committee Engineers' Club Report (1892).......530 19. Cohen and Hefford (1892)..........531 20. Discussion Soc. Chem. Ind. (1893). ..532 21. Reuss (1893).............532 22. Thomson (1894—5) ...........535 23. Clowes and Feilmann (1895). ...536 24. Callan (1895)...........536 2.5. Wright (1895)............536 25A. Mabery (1895)............536 26. Re- (1896). ..........536 27. Herman (1896)............ 537 28. Cohen and Russell (1896).......... 537 29. Dennstedt and A hrens (1896). ..537 30. Cohen (1897). ...........537 31. Drehschmidt (1897)........... 538 32. Pfeiffer (1898). .........538 33. Fritzche (1898)............ 540 34. Ost and Wehmer (1899)........... 540 35. Donkin (1899). .........541 36. Beilby (1899)............. 643 37. Berthelot (1900)............ 544

Jan 1, 1908

By C. T. Young, J. L. Lytton

In recent investigations,1,2 the strength and thermal stability of dislocation substructures prepared by 5 to 25 pct room temperature tensile straining and recovery annealing at 120°, 160°, and 200°C have been studied in randomly oriented polycrystalline high purity aluminum. The techniques of transmission electron microscopy revealed that a major source of the strength and stability of dislocation substructures was the formation, during room temperature straining, of well-defined cells bounded by dislocation tangles which rearranged into nearly perfect dislocation networks during recovery, forming the boundaries of subgrains. The strength of such substructures increases with decreasing cell or subgrain size,2"6 and the formation of fine subgrain structures can provide thermally metastable strength at low temperatures and can favorably alter the course of primary creep at elevated temperatures.7'8 For maximum benefit, however, sub-grain growth should be reduced or eliminated. It was, therefore, decided to investigate the use of heterogeneous precipitation on dislocation networks as a means of imparting increased strength and thermal stability to subgrain structures through effective pinning. C.T. YOUNG, STUDENT MEMBER AIME, and J. L. LYTTON, Member

Jan 1, 1970

By Met B. E

During the operation of the Parkes process of desilverising, and in the earlier days of the continuous process, gold and silver were removed separately from softened lead bullion. Gold was removed in the Parkes process by a selective zincing, and -in the continuous process by treatment with zinc in a special de-golding kettle, in each case a crust being obtained carrying the gold and a small portion of the silver. Actually the process could have been more correctly termed a de-copperising process, on accountof the relatively large amount of this metal present, and its affinity for zinc, which caused it to enter the crusts produced.The crust was treated in reverberatory furnaces, where the bulk of the copper and zinc was removed in by-products, and the resulting "gold bullion" cupelled to give adore bullion containing approximately 2,000 ounces gold per ton.For the purpose of parting this dore, a small Balbach-Thum plant of 11 cells was used, and once each six months a short campaign was conducted on the accumulated metal.With the development of the process of de-copperising smelter bullion by means of sulphur, when a bullion averaging about .004% copper was constantly available for refining, the need for a separate de-golding process disappeared.The de-golding kettle of the Continuous Process...

Jan 1, 1937

By Robert R. Walden, LeMont West

K ENTUCKY'S first acid-grade fluorspar flotation Kmill, shown in Fig. 1, was placed in operation Aug. 1, 1952, by the Pennsylvania Salt Manufacturing Co. at Mexico, Ky. During 1951 a critical shortage of acid-grade fluorspar developed and it became necessary for the company to produce part of its fluorspar requirements. In 1951 the company purchased the Crider and Lennen metallurgical fluorspar mill and an adjacent stockpile of tailing at Mexico, Ky. The tailing, assaying about 26 pct calcium fluoride, originated from log washer and jig mill concentrators in the area. As the mill did not have a fluorspar dryer or convenient rail facilities, the company leased the Burleson concentrator at Marion, Ky., where these facilities were available. At Marion, Ky., on the Illinois Central Railroad, dry acid-grade fluorspar is transported direct to the company's Calvert City, Ky., hydrofluoric acid plant. The Mexico flotation plant was reconditioned and designed to produce acid-grade fluorspar from the jig tailing stockpile. The new plant flowsheet is shown in Fig. 2. The ore feed, old tailing, which contains 10 pct of waste rock and coarse gravel assaying approximately 8 pct CaF,, is bound together by sticky clay

Jan 1, 1955

By J. G. Groppo, A. E. Bland, B. K. Parekh, W. F. Stotts

Many coal preparation plants discard fine coal (generally minus 100 mesh) because it is difficult to beneficiate economically. At the Kentucky Energy Cabinet Laboratory (KECL), the waste streams from several Kentucky preparation plants were evaluated for cleaning with counter-current column flotation. A series of performance evaluations were conducted using a 0.05 m (2 in.) internal diameter (I.D.) 7.9 m (26 ft.) high laboratory column. The objectives of these tests were to assess the performance in terms of recovery and percent ash in clean coal and to optimize the operating parameters relative to combustible recovery and grade. Refuse streams containing 30-50 percent ash were upgraded to 2-8 percent ash with Btu recoveries of nearly 90 percent. A pilot scale column flotation cell was installed at the Bell County Coal preparation plant. This pilot plant utilized a 5.79 m (19 ft.) high and 0.15 m (6 in.) I.D. column to verify the performance data of the 0.05 m (2 in.) I.D. column for two different waste streams. Performance evaluation and pilot plant testing results related to scale-up are discussed.

Jan 1, 1988

By D R. Peacor, J L. Mauk

Dioctahedral clay minerals in the volcanic-hosted Golden Cross epithermal Au deposit, New Zealand, have been investigated by petrography, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy/analytical electron microscopy (TEM/AEM) to determine the nature of these minerals in a hydrothermal ore deposit. Heterogeneity in the distribution of dioctahedral clays is observed from the hand-specimen scale to the TEM scale, indicating that primary rock textures and fluid pathways (related to rock type, porosity/permeability and fluid/rock ratios), in addition to temperature, are important factors controlling the distribution. As the proportion of illite in mixed-layer illite/smectite (I/S) decreases, TEM observations show decreasing layer stacking order, parallelism of packets, and packet size, and increasing apparent porosity. AEM structural data show a corresponding decrease in AlIV, AlVI, and K+, and an increase in Si, Ca2+, and Fetotal. The observations of this study indicate that local dioctahedral clay mineral reaction progress is controlled mainly by permeability and structure, but that this is superimposed on a predictable, system-wide clay mineral distribution that is controlled by temperature and fluid/rock ratio.

Jan 1, 1999

Impala Platinum?s No.16 Shaft mine is currently under construction and is expected to reach full production of 256 500 tons per month by 2014. Mining will start at 1 260 m below surface with a maximum mining depth of 1 535 m where virgin rock temperatures of 56.6°C will be experienced. As a result of depth, high virgin rock temperature and narrow reef mining, an expected total of 31.5 MW[R] of air cooling capacity will be required to achieve acceptable underground conditions. This will be achieved by cooling mine intake air in a single dedicated air cooling installation located on surface. The compact installation includes air cooling spray chamber, refrigeration machines, condenser cooling towers, evaporator and condenser water reticulation as well as all electrical and control systems. Construction and commissioning of the first phase of this air cooling installation has recently been completed on a turn-key contract basis.

Jan 1, 2009

By A. C. Dorenfeld

In most mineral enterprises, what is the progress, and shift in responsibilities, as the young engineer advances in the corporation? You are all familiar with the normal pattern-in mine production from level boss, to shift boss, to superintendent to manager; in milling from test engineer, to shift boss, to foreman, to superintendent and then manager; in engineering from surveying on to Chief Engineer; and all then aspire to the corporation presidency. Note the shift-from purely technical jobs, say in the first five to ten years in the profession, to administrative positions for 30 to 40 years. What is the average preparation given to mineral engineering students, who can look forward to about 30 years of administrative work? From the catalogs of 21 institutions, offering 36 curricula of four years length, in mining and/or metallurgy, requiring the equivalent of about 150 to 160 semesterhours for graduation, the following results were obtained: Average number of semester hours of economics, 3 hr. Range of requirements, 0 to 8 hr. Thirteen curricula do not require any economics. Accounting and business law, average: 1 semester hr, 26 curricula do not require business law or accounting.

Jan 2, 1955

By Dunkin H. H

Flotation tests in a laboratory flotation cell at pH 8-8.5 and other sui}plementary tests were carried out on sphalerite-quartz and sphalerite-pyrite-'quartz mixtures. Depression of sphalerite resulted vvhen the addition of copper sulphate exceeded an optimum value. Evidence that this depression was due to collector deficiency because of reaction between copper sulphate and collector is presented. It was not found possible to devise a direct analytical method suitable for .plant control of reagent addition. A possible means of control using potassium cyanide and a higher pH is discussed.INTRODUCTIONAt the Rosebery mill of Electrolytic Zinc Co. of Australasia Ltd., recovery 'of sphalerite in the zinc concentrate occasionally drops unexpectedly. Experiment in the mill and mill laboratory has suggested that one of the factors causing this may be the addition of more than an optimum amount of copper sulphate. On such occasions, an increase in the collector addition improves zinc recovery in the zinc concentrate, but only at the expense of sphalerite-pyrite selectivity.To examine the phenomenon more thoroughly, and if possible to find some means of determining the optimum addition of cepper sulphate and controlling the actual addition at this optimum, one of the authors (W. J. T.) was employed by the Electrolytic Zinc Co. of Australasia' to carry out investigations in the Mining Department, University of Melbourne, under the joint direction of R. B...

Jan 1, 1954

By Hisashi Takahasi, Hironobu Yamazaki

INTRODUCTION The slurry shield method was developed in Japan in 1963 and its experimental tunnelling work was performed in 1965. Although the history of this method is short compared with the conventional shield method in Japan, many companies such as Tekken Construction, Okumura Gumi, Nishimatsu Kensetsu, etc. are engaged at present in developing their own unique system of the slurry shield method. The ground of Japan is generally pervaded with ground water and a large number of districts are covered with soft ground, which is composed of fine sand, silt and clay, etc. Therefore, the conventional shield method has always used compressed air with various kinds of auxiliary methods. However, with this method there have been experienced numerous troubles such as ground settlements, lowering of ground water, oxygen shortage within the tunnel, and so forth. The slurry shield method has been developed with the above background. In recent years remarkable progress has been made from the engineering viewpoint in applying this method to driving various kinds of tunnels such as road tunnels, subways, water supply and sewer tunnels, and other tunnels. Apart from Japan, the slurry shield process using bentonite is carried out in England and Germany. OUTLINE OF SLURRY SHIELD METHOD (1) System of Slurry Shield Method Since the conventional shield method drives tunnels using com-

Jan 1, 1976

In several of the States of Australia, mining on private property has been seriously hampered by the fact that large areas of land have been alienated from the Crown before the discovery of gold or other minerals. In Western Australia this difficultyhas only occurred to a small extent, and has largely been overcome by an act entituled "An Act to Permit Mining on Private Property, No. XXIX., 'October, 28th, 1898." Under this act, the holder of a miner's right can apply for a gold mining lease on private land; such applicant may treat privately with the owner of such land as to the amount of compensation to be paid for surface ,damage, or the case may be brought before the Warden who will assess the damages. Private land used as a garden, orchard, or vineyard is exempt from lease, unless the applicant has authority from the owner, or such lease is limited to a greater depth than 100 feet from the lowest part of the surface.No lease shall be granted of any mines under any private land in any municipality unless either the applicant has authority from the owner, or such lease is limited to a greater depth than two hundred feet from the lowest part of the surface.The same regulation applies to leases of private land on which any hospital, asylum, or public building is situated or under or within one hundred and fifty yards laterally of any...

Jan 1, 1901

By Robert J. Maron, Mark Fernald, Alex Van der Spek, O’Keefe. Christian, Tim Bailey

"Sonar array-based non-invasive flow measurement technology is becoming an accepted and many times a preferred method of measuring challenging single and multi-phase flows in the mineral processing industry. This fundamental sensor and measurement technology has been extended to two developments that provide new measurement capabilities useful for monitoring and managing slurry flows and pipes.The first development is the non-invasive measurement of real-time velocity profile of slurry flow in horizontal pipes. Multiple non-invasive passive sensors measure localized velocities and are combined to provide a velocity profile measurement. This information can be used to determine the approach and onset of solid deposition on the bottom of the pipe. Having this information in real time can enable operation at lower velocities and/or higher solids concentration while avoiding solids deposition or plugging and its associated operational costs.The second development is the non-invasive measurement of pipe wear on slurry lines. Presently, such measurements are made by hand-held portable ultrasonic thickness gages. The numerous shortfalls associated with the manual method are overcome with a set of permanently or semi-permanently installed transducers clamped onto the outside of the pipe. This ring of sensors contains a series of conformable ultrasonic transducers spaced around the circumference, which are used to measure the thickness of the pipe under their respective locations. Compared to manual methods, this system and approach results in better repeatability and accuracy. It also decreases inspection labor costs and pipe access requirements. The minimal accuracy variations in the presence of varying environmental temperatures will be shown. Trending of pipe wall thicknesses in high wear pipelines will be illustrated. The benefits of significantly improved pipe wear monitoring in hydrotransport lines with abrasive solids, and associated improvement in the ability to insure safe operation and avoidance of costly environmental damage due to leaks caused by pipe wear will be discussed."

Jan 1, 2009

By David G. Almond

"Economies of scale and the variable characteristics of many large ore deposits have resulted in grinding installations having large SAG mills fitted with variable speed drives. Problems associated with effective operation of this equipment has created the need for better operator knowledge of mill load behavior and the need for new instrumentation capable of providing accurate information about load movement and composition. This paper discusses two performance enhancing instruments available to address these needs.INTRODUCTIONThe economic demands of new mining projects has resulted in increased equipment sizes and this is particularly evident in milling where there are now many SAG mills operating in the range of 28’ – 40’ diameter with installed powers of 8 – 22 MW. These mills are designed to process very high capacities of ore daily2 and the variable characteristics of many of the deposits mined results in the need to vary the mill speed during processing to cater for the changes in ore hardness. Mill speed changes often result in operational problems associated with high-energy impacts striking the mill liners reducing energy efficiency as well as degrading the grinding media through breakage, accelerating liner wear and in extreme cases even breaking liners. These operational problems have given rise to the need to have instruments aimed at providing operators with accurate information in real time about the load composition and movement within SAG mills.The original concepts for operating SAG mills were derived from past experience of operation of conventional fixed speed ball mills. However, the relatively stable conditions that applies with fixed speed and constant ball charge in ball mills supports theoretical approaches to the grinding process based on energy calculations such as Bond’s Work Index concept. Later a set of parameters Si and Bij were used for describing load kinetics, but all of these methods neglect the details of load movement and how the energy is actually used inside of the mill. It is now commonly accepted as a basic rule that SAG mills grind by impact whilst ball mills grind by attrition and consequently SAG mills are designed and operated to generate a large amount of impacts by the cataracting load without paying sufficient attention to where these impacts are actually occurring. Many mills are operated on the basis that as long as the mill is consuming the expected power there is little attention given to the class of bodies using this energy and this often results in the inefficient use of energy."

Jan 1, 2005

By SH. Shahsavari, H. Akbari, M. Noaparast, M. Oliazadeh

Mejel valley zircon ore in Iran is located in north part of Iran and was sampled to evaluate its concentration. The aim of this project was to define the mineralogy of this zone and separating zircon from other minerals using gravity concentrators and magnetic separators. It is constituted of various valuable minerals, mainly zirconium, niobium-tantalum, titanium, rare earth elements particularly cerium-bearing minerals namely zircon, sphene and rare earth elements oxides. We used statistical method for designing of experiments. Yates method used for analysis of basic experiments results. The grade of zircon in primary sample was 1.1%. Different experiments were designed to optimize all required parameters. The final concentration with 75% zircon was produced and final recovery was 79%. Finally, lab-scale based flow sheet was prepared using experiments results.

Jan 1, 2005

By Paul D. Klipfel

Introduction Mineral exploration interest, principally for gold, in the south-western Pacific has surged to new proportions. This is primarily due to the application of epithermal exploration concepts in the Australian-Oceana region. Other factors that have contributed to the high level of exploration interest include governmental policies supportive of mineral exploration, along with relative ease of tenure access and a relatively short bureaucratic process. This paper highlights exploration and development activities in the North Island of New Zealand, Fiji, Vanuatu, the Solomon Islands, and Papua New Guinea (Fig. 1). It provides a framework to understand the overall recent enthusiasm that has been brought to the south Pacific by explorationists. Through these recent developments, it is clear that the south Pacific region will become a significant gold producing area and thereby worthy of attention and study. Papua New Guinea alone is the free world's seventh largest producer (Table 1). And, with the addition of production from deposits presently being developed, this status is likely to be raised. History Gold was first noted on various Pacific islands in the late 1500s by Spanish explorers. They thought they had reached the legendary King Solomon mines. Since then, the history of prospecting in the southwest Pacific has coincided with the colonization of the region. Settlers in New Zealand extensively mined alluvial and lode gold deposits starting in the 1850s. The spread of European colonization to the more remote Pacific islands from 1880-1940 was accompanied by varying degrees of prospecting activity by planters, traders, and settlers. Some were successful, others may have been successful, but never returned due to hostile indigenous peoples or disease. In general, records of such prospecting activity are meager and exploration leads are, in some cases, gained through local village folk memory. Most early discoveries were alluvial finds. These led to placer operations, particularly in New Zealand, the Solomon Islands, and Papua New Guinea. Continued prospecting located lode deposits such as the Morobe Gold-field of Papua New Guinea, the Coromandel Peninsula of New Zealand, and the Emperor of Fiji. Some areas were prospected thoroughly. Yet others, such as Vanuatu, remained relatively unexplored until the present exploration surge began. During World War II, interest in minerals was diverted. It was renewed significantly until the middle 1960s and early 1970s when regional porphyry copper exploration was conducted.

Jan 10, 1987

By Ivette E. Torres

Aruba, formerly a. part of the Netherlands Antilles, separated on January I, 1986, and became an autonomous part of the Netherlands. Full independence of the island from the Netherlands is scheduled for 1996. In this chapter, however, Aruba's statistics are included with those of the Netherlands Antilles. Tourism continued to be the main industry of the island, which continued to depend heavily on imports, mostly from the United States. During the year, the Government was preparing legislation to regulate the exploration of oil deposits in the relatively shallow sea around Aruba.

Jan 1, 1989

By H. D. Kline

This publication describes mining and milling methods and costs at the Madison mine of National Lead Co., St. Louis Smelting & Refining Division, in the Fredericktown district of southeast Missouri and is one of a series prepared by the Federal Bureau of Mines on methods, practices, and costs of mining and milling throughout the United States. The are bodies of the Madison mine are known for the complexity and diversity of their are minerals. Sulfides of copper, nickel, and cobalt occur in commercial quantities with lead sulfide, which is the most valuable metallic mineral in are bodies of the Bonne Terre formation in southeast Missouri. Several attempts were made by various operators to mine the complex ores and separate the sulfide minerals before 1927 when National Lead Co. became interested in the Fredericktown district. Operating then as the St. Louis Smelting & Refining Co., the company began mining and milling ores from the Madison mine in 1944 and has operated continuously since then. A recently built refinery produces copper, nickel, and cobalt metal from a concentrate containing iron sulphides and small quantities of copper, nickel, and cobalt sulphides.

Jan 1, 1961

The results of precious metal exploration carried out by Amoco Minerals New Zealand Limited over EL 33-137 in the Longwood Range, Southland, are described. Widespread gold and platinum in alluvial deposits on the perimeter of the range and anomalous gold in stream sediments on its southern and south western flanks indicates that the precious metals were probably derived from erosion of the mafic rocks of the Longwood Complex.

Jan 1, 1983

By L C. Taylor, H U. Lesiste

This is a preliminary study of the statistical variation of the pressures on a target above a buried explosion. The data were taken at various distances from the charge centerline for three heights of the target above the soil and one charge depth of burial. All tests were conducted in saturated sand. They show that peak pressures and times of peaks are neither repeatable from shot to shot nor rotationally symmetric within a single shot. The peak pressure and time of peak at each location can be represented by cumulative normal distributions. The paper describes the means and standard deviations of these distributions at eight distances from the charge center for each height of target. These are used to determine the change in standard deviation of the distribution with distance from the charge centerline and height of target. The effect of scale on the mean peak pressures and times of peaks and on their standard deviations at a single scaled distance from the centerline of the charge are explored using various charge weights.

Jan 1, 2010

By Bill Shand

"Placer Dome - Campbell Mine is a gold mine located at Balmertown in the Red Lake District of North Western Ontario. During the last 50 years, the mine has produced over ten million ounces of gold.A change in ball mill grinding media was made in August 1998 from 1.5” diameter forged balls to 1.5” diameter, 18% chrome balls. This was done to reduce grinding media consumption and to potentially help flotation performance.A marked ball test done in September-October 1999 showed that, of the alloys tested, 18% chrome was the optimum for the ore at Campbell Mine. The test showed that consumption of chrome balls should be 3 times less than forged balls.In December 1999, the ball size was increased from 1.5” to 2” in an effort to reduce the amount of oversize rock discharging from the ball mill. This change in size was successful.Grinding media consumption for the ball mill decreased 73% from 1.20 kg/tonne before the use of chrome balls to 0.327 kg/tonne after the use of chrome balls. This clearly indicates that, for the ore at Campbell Mine, there is significant savings in grinding media by using chrome.Grinding ball costs were reduced by 59% from $O.88/tonne of ore milled to $0.36/tonne of ore milled representing a saving of $298,000 per year. This also clearly indicates that using chrome balls is a benefit at Campbell Mine.Test work to show that chrome grinding media is beneficial to flotation has been inconclusive so far but is still ongoing.No tests have been done to see if there would be a benefit with an even higher chrome percentage in the grinding media. Test work in this area is also planned for the future"

Jan 1, 2001