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In discussing Mr. Keller's paper, I quoted the results obtained by Mr. Allan Gibb, correctly crediting them to Mr. Gibb, with due reference to the report in which they were published. But in the table immediately following, and in my further remarks, following the table, I find that, by some clerical or other error which I cannot, after the lapse of time, explain, I spoke of Mr. Gibb as Mr. "Dean"—a metallurgist who had written on a related subject, but not on the point I was discussing. In short, my reference throughout was to the work of Mr. Gibb; and by reading a Gibb " for a Dean " in all places on pp. 832 and 835 where the latter name occurs, my remarks will be brought into accordance with my intention, and with the facts.

Jan 1, 1901

By W. G. Whildin

This paper will be confined to a discussion of the methods in use in the property of the Lehigh Coal & Navigation Co. in the Panther Creek valley. Only the methods used in mining the Mammoth vein will be .considered, as the methods in use in the smaller veins are adaptations of the same. Typical cross-sections of the coal basin are shown in Figs. 1, 2, and 3. The Mammoth vein varies in thickness. It is 21 ft. at one colliery, 50 to 125 ft. at another, and over 200 ft. at still another. Its normal thickness is 35 to 40 ft. At some points in the Panther Creek basin the Mammoth vein is made up of three splits-the Bottom, Middle, and Top, while in other portions the dividing strata between the benches amount to only 1 ½ to 2 ½ ft., and the vein is practically in one. The section of the Mammoth vein shown in Fig. 4 was taken at the Greenwood colliery, and shows a thickness of 60 ft. The miners know it by benches, as follows:. The Three-Foot, the Four-Foot, the Eighteen-Inch Slate, the Bony, the Grey Slate, the Grain Clear, the Five-Foot, the Seven-Foot, the Slaty or Dirty benches, the Blue Slate, and the Top bench. The present-day methods of mining are an outgrowth of the experiences of the last 100 years in this territory. The first attempt at mining, according to the company's maps, was made at Summit Hill in 1792, when open cuts and pits were made. Later the pillar-and-breast method was introduced. This and other methods will be discussed hereinafter. Drifts, slopes, and shafts, according to the requirements and physical conditions, are the main openings, from which the gangways are driven. The gangways (haulageways) and airways are driven along the strike of the vein; the gangways in the various veins on the same level being connected by tunnels through the intervening rock. The gangways and airways in thick veins are heavily timbered ;throughout. The sets of timber, consisting of a collar and two legs, are spaced 5 ft. apart, and later, after the ground :has settled, additional sets, called "liners" or "relief sets," are placed between, to relieve the strain on the original timbers, so that the result is a set of timber every 2 ½ ft.

Jan 12, 1914

By Brett K. Mainer

In the summer and fall of 2007, Drill Tech Drilling and Shoring, Inc. designed and built three 24-foot inside diameter shafts in Northern California using soil mix panels for support. The soil mixing was performed using the Bauer Cutter Soil Mix (CSM) method, by which rectangular soil mix panels up to 71 feet deep were arranged in an overlapping manner to form a 24-foot inside diameter circle. The shafts were then excavated to depths up to 51 feet. One of the shafts was a test shaft and used only the soil mix panels for support. The other two shafts were located immediately adjacent to the Mokelumne River and were used as access pits for a microtunnel drive under the river. These two shafts had wide flange beams embedded in the panels and were supported with several levels of ring steel placed during excavation. This project was the first use of the Bauer CSM method in the United States. The CSM method has been used extensively in Europe and Asia, but never for this application and never with this high a loading criteria due to water head and microtunnel reaction forces. Soil conditions at the river crossing shafts consisted of sands, gravels, and cobbles over top of sandstone and conglomerate bedrock ranging in strength up to 5,000 psi. Groundwater was within several feet of the surface. The shafts were successfully completed between October 2007 and January 2008, and the microtunnel was successfully completed in February 2008. This paper provides discussion regarding selection of the shoring type, structural design, the soil mixing method, and the mix designs. Shaft construction, shaft performance, and the capabilities of the CSM equipment are presented.

Jan 1, 2008

By J. C. M. De Souza

The Samarco pipeline, the longest in the world for iron ore slurry transportation, started operation in 1977 to transport concentrate from the Germano facilities, in the state of Minas Gerais, to the pelletizing plant, located 396 km away, in the state of Espirito Santo, on the south-east coast of Brazil. Designed for a nominal capacity of 12 million tons per year, the pipeline reached 15.5 million/year due to operational improvement and, in late 2005, it was resized to transport 16.5 million tons per year, with the installation of a booster station. In order to ensure the accurate performance of the system, a pipeline cleaning programme was carried out and, since it has been 29 years from the operation start-up, precise knowledge of the pipe condition would be fundamental to guarantee the success of the project. The cleaning programme demonstrated the potential of operational gains from this initiative, and its effect on the corrosion control and future measures, which should be permanently adopted to maintain the improved capacity. The intelligent pig runs provided essential data used to establish a pipeline integrity programme that allowed Samarco to develop a pipe repair plan based on the severity and significance of the features and to implement a future pipe replacement plan.

Jan 1, 2007

By P. Barnes

In vol.33 of the Proceedings of the Institution of Civil Engineers, London (part 2, for 1870-71), may be found a statement of the cost of two blast furnaces, together with a somewhat detailed description. The attempt will he made in this note to restate these items of cost, so that the information may be rendered perhaps more accessible to our members than in its present place of record, and also in order that the items may be more intelligibly compared among themselves, or with similar items in other cases.

Jan 1, 1879

Radioisotope X-ray and neutron techniques of analysis can be used for the determination of a wide range of elements in minerals. The most important applications of these techniques to the mineral industry are for on-stream analysis of slurries and solids, and for geological assay. The radioisotope X-ray techniques are the more developed ones and two installations for on-stream analysis are in routine use in mineral processing plants in Australia. Neutron techniques are being developed, and should prove valuable for geological assay of large numbers of mineral samples, for borehole logging, and for specific on-stream analysis when the cost of the equipment is warranted.

Jan 1, 1969

By J. Schlocker

The present emergency has greatly stimulated interest in the light metals - aluminum and magnesium - owing to their extensive use in airplane construction. The $63,000,000 plant being erected in the Las Vegas Valley by Basic Magnesium, Inc., under the auspices of the Defense Plant Corporation,

Jan 1, 1942

By William A. Hustrulid

INTRODUCTION Prior to the mid-1970's, the U.S. Radioactive Waste Disposal Program was focused on salt deposits as the geologic medium of choice, almost to the exclusion of other rock types. These efforts are illustrated by the Project Salt Vault experiment in a salt mine at Lyons, Kansas, in 1965-1967 followed by attempts to locate a repository site in central Kansas. Preliminary evaluation of other geologic media led, in 1978, to the GAIN (Geotechnical Assessment and Instrumentation Needs for Nuclear Waste Isolation in Crystalline and Argillaceous Rocks) Symposium held at the University of California (Berkeley), for the purpose of preparing a state-of-the-art document together with research needs for some of the other possible rock types. Because possible sites had not been selected, nor would they be for some time, the primary emphasis was for research and development focused on generic rocks and generic sites. A basic ground rule at that time was that the host rock formation should provide the primary containment for the waste. Also, the U.S. Nuclear Regulatory Commission (NRC) was just drafting the proposed rules regarding site suitability so that this input was not available. The collection of baseline data, conduction of some critical experiments both in the laboratory and field, and the performance of scoping studies were deemed needed. Such work was indeed undertaken; and to date, a great deal of information has been compiled and much has been learned regarding the characteristics of rock masses, rock behavior

Jan 1, 1984

By C. H. Perbix

[On Pier D in the Port of Long Beach, California, the Port of Long Beach has built a new bulk cement distribution terminal. The facility is operated by Pacific Coast Cement Corporation, who designed the complex and leased it from the Port of Long Beach on a 40-year lease. At one bulk cement is unloaded from vessels carrying from 12,000 to 30,000 t. The unloading is performed with pig speed mechanical unloading equipment and delivered into a concrete silo complex with, a capacity of 50,000 t. From the silos, bulls cement is loaded into trucks for delivery. The facility was completed in September 1981.]

Jan 1, 1983

By Cheryl Lee Vatter

The Lupin mine consists of a gold mining, milling, and refining complex located 400 km (250 miles) northeast of Yellowknife and 100 km (60 miles) south of the Arctic Circle on the southwest shore of Contwoyto Lake in Canada's Northwest Territories. (Fig.1). The mine was commissioned in 1982 and is presently producing 6 t/a (193,000 oz per year) of gold from 612 kt (675,000 st) of ore. The success of this operation is due to such factors as the continuity and grade of the ore body, the competency of the host rock, low mining costs, efficient milling, the transportation of people and materials to and from the mine site, and the unique work schedule resulting in a stable workforce. Echo Bay Mines operated a silver mine at Port Radium on Great Bear Lake, Northwest Territories, from 1965 to 1982. The company first obtained an option on the Lupin property from Inco in February 1979 and completed an underground exploration program in 1979-1980. Topographic relief is low and vegetation is sparse in the continental subarctic climatic zone, consisting mainly of moss and lichens. Temperature extremes are from 24°C to - 45°C (+75°F to -49°F) with an annual mean of -12°C (+54°F). Permafrost extends from near surface to 500 m (1640 ft) in the ore zone. Its remote location and harsh climate presented some challenging design and logistical problems. Construction began at the Lupin mine site in 1980. Before construction, a 1.5-km (5000-ft) gravel landing strip was prepared, suitable for landing a C 130 Hercules. The entire Lupin project took 20 months to build. All of the men and materials were transported to the site with some 1100 Hercules flights and several hundred Convair 640 flights. The Convairs transported construction crews, which numbered 400 at their peak, and also carried 3.2 kt (3535 st) of supplies during construction. The facilities were constructed and commissioned for a total cost of C$135 million. The operation was originally designed to throughput 860 t/d (950 stpd). Expansion in 1983, circuit refinements, and some capital projects brought the daily throughput to 1.7 kt/d (1850 stpd). The underground mine delivers 612 kt/a (675,000 stpy) of ore to the mill at an average head grade of 8.46 g/t (0.3 oz per st). The ore is nonrefractory and is processed in a conventional cyanide leach using the Merrill Crowe process. Gold recovery is about 95.0%. The average production cost is $US5.85/g ($US 182 per oz) based on 1987 figures. Mining at Lupin – Geology The Lupin deposit occurs in amphibolite grade iron formation overlain by mudstones (phyllites) and underlain by graywacke (quartzites). Contacts between the wallrock units and the iron formation are well defined. It has been folded and tilted into a megascopic antiform-synform-antiform structure (Fig. 2). Gold occurs primarily within the sulfide rich iron formation, with some minor occurrences in sulfide poor iron formation. The distinction between sulfide rich and sulfide poor iron formation is based on a visual cutoff of 5% total sulfide content. Mining widths are determined by an assay cutoff of 4.2 g/t (0.15 oz per st) gold. There are few tons between 1.7 and 4.2 g/t (0.06 and 0.15 oz per st). The amphibolitic iron formation at the mine ranges from 1.5 to 20 m (5 to 65 ft) wide and has been followed over a strike length exceeding 1.7 km (5600 ft). The wider portions of the ore body tend to occur at its north extent and south nose. The gold-bearing iron formation appears on plan as a Z-shaped structure made up of three zones: the West, Center, and East. The West and Center zones dip steeply to the East (75° to 90°). Each of the ore zones plunge at an angle of about 65°. Total strike length of the three zones is more than 610 m (2000 ft). The zones are confirmed at a depth of 650 m (2130 ft) below surface. The Center zone is the widest and varies from 4.5 to 20 m (15 to 65 ft) while the West is the narrowest, averaging 1.5 m ( 5 ft). The footwall is comprised of quartzites that are strongly jointed and locally grades into phyllite, which comprises the hanging wall. The hanging wall and footwall are reversed in the West zone. Mineralogy of the ore at Lupin consists of amphibole minerals (hornblende, cummingtonite, and grunerite), feldspars, quartz, occasionally garnet, pyrrhotite, arsenopyrite, minor pyrite, and trace chalcopyrite. Also found in minor amounts are scheelite, apatite, epidote, calcite, tourmaline, and some arsenides (notable loellingite). Quartz

Jan 1, 1989

By Ronald W. Utley

INTRODUCTION The ''Do's and Don'ts" of installing equipment in a comminution circuit begin during the study stage of a proposed project, continue through preliminary engineering, detail engineering, procurement, the actual placement of equipment at the job site, and end with turnover to the owner. Equipment supplied for a modern comminution circuit will be high quality, rugged machinery designed according to appropriate manufacturing standards for long hours of trouble-free service. However, certain precautions and procedures must be observed in plant design and layout, equipment handling, installing and servicing in order to obtain optimum performance. This chapter contains general installation "DO'S and Don'ts" for the major equipment in the circuit. •Primary Gyratory Crushers •Rock Breakers (Hammer) •Belt Conveyors •Apron Feeders •Weigh Belt Scales •Secondary Crushers •Vibrating Screens •Grinding Mills •Mill Liners •Open Gear Sets •Speed Reducers •Electric Motors •Cyclones •Slurry Pumps Some questions will not be covered in this chapter, or may not be applicable to the actual equipment purchased, as requirements do vary from manufacturer to manufacturer. Additional specific information can be obtained by contacting the manufacturer's local representative or the factory. All inquiries should be accompanied by the following information: •Unit size and type of equipment •Manufacturer's shop order number (after order placement) •Serial number (after manufacture) DO'S 8 DON'TS FOR INSTALLATION OF ALL COMMINUTION CIRCUIT EQUIPMENT Installation By Design DO obtain tables of weights and clearances from manufacturer. DO obtain WR2 forces from manufacturer to determine that the foundation is adequate. DO determine compression strength of foundation soil and/or rock. DO obtain manufacturer's recommended typical foundation drawings. If substantial alteration to manufacturer's drawings is required, check with the manufacturer before proceeding.

Jan 1, 1982

Host minerals for gold have been of great interest to exploration geologists and metallurgists for a variety of reasons. The depletion of high grade ores in many parts of the world requires that greater attention be given to the study of host min-erals for gold. Some host minerals have been employed in exploration as traces for gold. They are also essential in the design of extraction processes for treating gold ores.This paper reviews the mineralogy of important gold deposits of Papua New Guinea (PNG), Indonesia and New Zealand and focuses attention on the ore minerals and rock-forming minerals that host gold.

Jan 1, 1994

By Trevor I. Addenbrooke

Stress reducing piles were used for the first time at the Queen Elizabeth II Conference Centre near the Palace of Westminster in London, UK. The inclusion of these piles directly beneath heavily loaded columns was to reduce the high anticipated bending stress in the foundation raft, and to eliminate local yield of the London Clay beneath the column locations. Load cells were placed in one of the stress reducing piles during construction. The data showed that the pile carried about 30% of the column load. This can be contrasted with conventional piled raft design where the pile carries upwards of 80% of the column load. The build up of load on the pile and pile displacement have been accurately reproduced using coupled finite element analysis. These numerical results demonstrate the value of geometrically simple axially symmetric analyses for modelling a pile-enhanced raft. On site, excavation preceded construction of the raft and subsequent pile loading. Failure to model this construction sequence caused the shear strength to mobilize at the base of the pile first, during loading, whereas following the construction sequence caused the shear strength to mobilize at the top of the pile first.

Jan 1, 2002

By H. Senoh

For the purpose of clarifying the reason caused a drastic decrease of discharge capacity for MmNi3.6Mn0.4Al0.3Co0.7 electrode at relatively low temperatures, various factors influencing the charge-discharge processes were investigated in the temperature range of 25°C to -40°C. The charge efficiency obviously decreased at low temperatures less than 0°C due to a decrease in the rate of the charge-transfer reaction on the electrode surface. Moreover, both the rate of the hydrogen diffusion from the alloy bulk to surface and the rate of the charge-transfer reaction significantly influenced the high-rate dischargeability. The addition of Mo to MmNi3.6Mn0.4Al0.3Co0.7 alloy was found to be effective for improving the electrocatalytic activity, leading to the improvements of the charge efficiency and the high-rate dischargeability at relatively low temperatures.

Jan 1, 2002

By I. Orford, V. Rozon

"The Sä Dena Hes Joint Venture Mill was designed to process 450,000 tonnes per year of ore grading 11.3% lead and 13.2% zinc.Run of mine ore is crushed in a jaw crusher and then ground in a closed circuit SAG mill and ball mill. A standard differential float in conventional flotation cells produces quality lead and zinc concentrates. Dewatering of concentrates is achieved using high rate thickeners, lamella clarifiers and pressure filters. Process water is 100% recycle.Plant design was based on metallurgical test work performed on drill core samples. The plant is operating at better than design specifications.INTRODUCTIONSä Dena Hes Joint Venture was formed in 1989 to develop the Sa Dena Hes lead/zinc sulphide mine, located approximately 45 km north of the Town of Watson Lake, Yukon. The mine is owned by a Joint Venture partnership between the operator, Curragh Inc. (87.5%) and Hillsborough Resources Limited (12.5%).The project was completed in a record ten months, working throughout the severe Yukon winter and through an abnormally wet spring and summer. The first truckloads of concentrate were shipped from the mine on August 1, 1991.The mill currently processes 550,000 tonnes of ore per year grading 6.9% lead and 11.5% zinc. Ore is crushed in a jaw crusher and ground to 60% passing 75 microns in a closed circuit operation of one SAG mill and ball mill. Using conventional flotation cells a 150,000 tonnes of concentrate is produced in a year with lead concentrate grading 78% lead and a zinc concentrate grading 60% zinc at overall recoveries of 89% and 90% respectively.Concentrates dewatering is accomplished using high rate thickeners, clarifiers and pressure filters. The lead concentrate and zinc concentrate contain 5.4% water and 7.8% water respectively. Concentrates are trucked to Skagway, Alaska for subsequent shipping to overseas smelters."

Jan 1, 1993

By Lynn C. Fister

"Coal is rapidly becoming a major alternative to oil. According to the World Coal Study Final Report, total world coal trade could approach one billion tons annually by the year 2000. To facilitate the increased production and export market potential of the coal producing countries, advancements must be made to improve the transportation systems. Coal slurry pipeline systems could play a significant role in achieving these market forecasts.There are three major components to a coal slurry system the preparation plant, the pipeline and the dewatering plant. The experience and expertise gained from the Consolidation Coal Company system in Ohio, the Black Mesa system in Arizona and ETSI's Coal Evaluation Plant demonstrate that slurry pipeline technology is proven and available to meet the coal transport challenge.The costs of transporting coal by slurry pipeline can offer significant savings, as about 70 per cent of its costs are fixed. The reverse is true for railroads, where 75 to 80 per cent of the costs vary with inflation. All forms of transport-rail, barge and pipeline-will be required to move the massive volumes of coal. Coal slurry systems can provide a viable transport alternative.IntroductionThe importance of coal as a major alternative to oil is now well known and accepted throughout the world. Increasing oil prices over the last eight years have had a serious effect on national economics, particularly in those countries that are heavily dependent on oil. Coal can replace oil as the principal fuel source which could support world economic growth over the next two decades. This is the main conclusion of the World Coal Study (WOCOL) Final Report, published in May 1980.The product of that report was a result of considerable deliberation by key industry leader s and energy experts. The underlying message of the World Coal Study is that our energy and economic problems can be faced with confidence if coal use doubles by the early 1990s and triples by 2000, and if steam coal trade expand s considerably."

Jan 1, 1982

By M. Karfakis, K. Kim, R. V. de la Cruz

The in situ deformability of a closely jointed basalt rock mass was determined by two different methods: the NX-borehole jack method where displacements of opposing curved platens were related to applied hydraulic pressures, and the modified Goodman jack method where tangential strains on the borehole walls were related to induced tangential stresses. The modulus obtained by the modified Goodman jack method were much higher than those obtained by the NX-borehole jack method. To explain the discrepancy, the influence of fractures and test variables, such as depth, orientation, hole location, and applied pressure on the calculated modulus of the rock mass, were analyzed by factorial analysis. It was found that the orientations and measurement depths have statistically significant effects. The in situ deformability values obtained by nonlinear regression analysis were also found comparable with other measurements and empirically predicted values for the basalt rock mass.

Jan 1, 1984

By Phillips J. T, Hutton W. A

This paper discusses why Argyle Diamonds adopted thickened tailings disposal in 1985 and how the system was developed over the next seven years. A wide ranging review of the thickened tailings disposal system and the tailings deposit it was producing was carried out during 1992 and 1993. The results of that review led to the abandonment of thickened tailings disposal at Argyle because of serious concerns about the stability of the resultant tailings deposit. The exposure to the risk of liquefaction and an assessment of the consequences if this happened to the thickened tailings deposit are shown. The criteria for selecting the new tailings disposal strategy are then described. The final section of the paper discusses the management strategies that have been put in place. These are designed to: ò reduce the risk posed by the thickened tailings deposit to an acceptable level; ò safely store tailings to the end of mine life; ò produce a land form that can be decommissioned to the satisfaction of Government regulatory bodies.

Jan 1, 1996

Study on Flotation Experiment of Complex Copper-Lead-Zinc Polymetallic Sulfide Ore in High Altitude Area and its Industrial Application

Sep 13, 2010

By S. C. Libby

The amount of fine material (minus 60 Tyler mesh) generated during calcination and/or handling of calcined abrasive grade bauxite from Alcoa's operations at Moengo, Suriname, has recently increased relative to past production experience. Bulk samples of raw abrasive grade bauxite from three deposits in the Moengo area have been studied in order to determine the factors controlling the generation of fine material samples from the Jones IC and Tapira deposits, which generate excessive amounts of fine material, have been compared with reference samples from the Begi Gado deposit, which does not generate excessive fine material. Additional type samples of abrasive grade and marginal abrasive grade bauxite from deposits in the Moengo area which represent different bauxite textures found in the Jones IC, Jones I, and Begi Gado deposits have also been studied. Field observations in the Moengo area have indicated that abrasive grade bauxites with a dull, earthy appearance generally do not generate excessive fines. On the other hand, excessive fines are generally associated with coarsely crystalline bauxite in which the gibbsite crystals appear to sparkle in sunlight.

Jan 1, 1980