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By A. F. Spinks, S. P. Nicholls

"The Lower Orebody at Chingola Division of Nchanga Consolidated Copper Mines, Limited, is a stratified orebody that is mined by a continuous caving system. The accurate determination of the developed and semi-developed ore reserves has always been difficult. The new system proposed in 1971 is designed to update and, as new informa¬tion becomes available, to account for the depletion of, the reserves.There are three main inputs to the system. These are borehole data, survey data and extractions data. The borehole data are input to a geological borehole master file system, which holds every recorded detail of a borehole in an easily extractable form. These data can be extracted for ore reserve calculations or for contour mapping of orebodies and rock types. The grades for use in the ore reserve calculations are extracted from the relevant boreholes.The survey data are information on the position of the blocks and drifts, taken from plans, and information on the scraper drift and trough drive positions taken from sections. The information is extracted from the plans and sections using a D Mac pencil follower. The ore reserve is calculated from the survey data and the borehole data.Data on extractions are taken from scraper operators' logs, tramming records, skips hoisted records and accepted mill tonnages and grades. Using these data, the mill tonnages are reconciled back to the drifts, to deplete the current ore reserves.As new workings are brought into operation and further evaluation holes are drilled, the relevant data are input and the new developed ore reserve is calculated."

Jan 1, 2014

By Stanley M. Walker

Safety consciousness is not a constant for which a specific value can be assigned, but is a variable, which is frequently intangible. Its evaluation is not simple. We all know that safety consciousness is the most potent factor in the prevention of accidents. Safety consciousness may be defined as awareness of hazard and alertness to danger, which controls every action of an individual through his desire to remain alive and uninjured.

Jan 1, 1951

By Dale A. Zuck

Recovery of aluminum metal from drosses? is a major factor in the recyclability success story enjoyed by the United States aluminum industry. Today's modern dross processor uses the latest technology to maximize metal recovery at the lowest cost while complying with all environmental laws and regulations. Most dross processors, however, pay little attention to the resulting saltcake, the end residual of dross recyCling, and rely on landfills for .disposition of this material.. The alternative is to recycle the saltcake, but the success of this technology is dependent on the development of reliable outlets for each of the saltcake constituents. This paper discusses the evolution of an aluminum dross oxide processing technology that ,produces an economically attractive source of alumina for the production of portland cement.

Jan 1, 1995

By Ludwig Schmidt

Steel tanks often corrode rapidly in oil fields where the gas produced with crude petroleum contains an appreciable quantity of hydrogen sulphide. In many instances working tanks have been discarded after only six months of service because of failure induced by corrosion. Aluminum has been used for some time in the fabrication of certain equipment incidental to the handling of oils containing hydrogen sulphide gas in solution, and has exhibited no serious corrosive action. These uses indicated that aluminum tanks might be equally effective in counteracting hydrogen sulphide corrosion. Consequently, in the spring of 1928, an all-aluminum stock tank of 500 barrels capacity and a "composite" tank of equal capacity, having a steel bottom and bottom ring and an aluminum top and top ring, were placed in service on the State-Lassiter lease of the Gulf Production Co. in Crane County, Tex. These tanks were under observation for one year, the test being sponsored by the Gulf Production Co., the Aluminum Co. of America, rind the Parkersburg Ric and Real Co. The results of this preliminary test sustained the belief that aluminum is highly resistant to hydrogen sulphide gas and likewise indicated the type or grade of aluminum which could be most economically used for lease tankage. However, in this preliminary test the Wake were not subjected to contact with the large quantities of highly concentrated brines such as often are associated and produced with crude oil. Therefore, it was suggested by representatives of .the Aluminum Co. that additional tests be made to include production conditions in which large quantities of brine would be handled, for past experience had shown that aluminum often is susceptible to the corrosive action of brines.

Jan 1, 1931

By Ludwig Schmidt

[Steel tanks often corrode rapidly in oil fields where the gas produced with crude petroleum contains an appreciable quantity of hydrogen sulphide. In many instances working tanks have been discarded after only six months of service because of failure induced by corrosion. Aluminum has been used for some time in the fabrication of certain equipment incidental to the handling of oils containing hydrogen sulphide L; as in solution, and has exhibited no serious corrosive action. These uses indicated that aluminum tanks might be equally effective in counteracting hydrogen sulphide corrosion. Consequently, in the spring of 1928, an all-aluminum stock tank of 500 carrels capacity and a "composite" tank of equal capacity, having a steel bottom and bottom ring and an aluminum top and top ring, were placed in service on the State-Lassiter lease of the Gulf Production Co. in Crane County, Tex. These tanks were under observation for one year, the test being sponsored by the Gulf Production Co., the Aluminum Co. of America, and the Parkersburg Rig and Real Co. The results of this preliminary test sustained the belief that aluminum is highly resistant to hydrogen sulphide gas and likewise indicated the type or grade of aluminum which could be most economically used for lease tankage. However, in this preliminary test the tanks were not subjected to contact with the large quantities of highly concentrated brines such as often are associated and produced with crude oil. Therefore, it was suggested by representatives of the Aluminum Co. that additional tests be made to include production conditions in which large quantities of brine would be handled, for pact experience had known that aluminum often is susceptible to the corrosive action of brines.]

Jan 1, 1931

By Peter M. Herzig

In 1994 and 1998 the German research vessel R/V Sonne undertook detailed mapping and sampling of the largely uncharted offshore areas of the Tabar-Lihir-Tanga-Feni island chain in the New Ireland Basin of Papua New Guinea. The New Ireland Basin occupies a fore-arc position with respect to the formerly active Manus-Kilinailau arc-trench system and hosts a series of Pliocene to Recent alkaline volcanoes which are built on rifted Miocene sedimentary basement. Several of the volcanoes possess high-level porphyry stocks and active geothermal systems, including gold-depositing hot springs and the giant (40 million ounces) Ladolam gold deposit on the island of Lihir. On the southern flank of Lihir island, a group of three volcanic cones were discovered at water depths from 1.000-1.500 m. The volcanoes are located in a narrow zone of recent seismic activity and elevated heat flow (up to 100 mW/m2). The recovered volcanic rocks consist of fresh alkali-olivine basalts, clinopyroxene-rich basalts (ankaramites), porphyritic phlogopite basalts, and trachybasalts. Unusual gold-rich hydrothermal precipitates were recovered from the summit of the 600 m high Conical Seamount located only about 10 km south of Lihir Island. 1200 kg of sampled material systematically collected with a TV-guided grab from the top plateau (150 x 200 m, 1.050 m water depth) are intensely mineralized with pyrite, marcasite, minor sphalerite, chalcopyrite, galena, tennantite/tetrahedrite, and orpiment/realgar together with traces of anglesite, cerrusite, and amorphous silica in stockwork-like veins. Bulk samples of the vein mineralization consist mainly of clays, silica, and disseminated sulfides, and have an unusual high gold content ranging from 1.2-44.0 ppm Au. In some of these samples, grains of native gold (about 1 micron in diameter) were identified by SEM in pyrite and sphalerite. The gold-rich material also contains high concentrations of silver (up to 1000 ppm) and typical epithermal elements such as As (2.6 wt.%), Sb (0.2 wt.%), and Hg (34 ppm). Similar to epithermal deposits on land, which usually have only low base metal contents, the samples from Conical Seamount contain only minor amounts of Zn (max. 4.5 wt.%), Cu (2.0 wt.%), and Pb (2.0 wt.%). Many of the samples recovered from Conical Seamount are virtually identical to the gold ore at Lihir.

Jan 1, 1998

E. E. Russell Tratman, New York City (communication to the Secretary): Mr. Glenn's paper brings up again the question of the part played by coal-dust in colliery-explosions. In the discussion of Sir Frederick Abel's paper on " Accidents in Mines," read before the Institution of Civil Engineers,? much was said about the dangerous properties of coal-dust, and several instances were given of the successful use of a spray of water, water and compressed air, or exhaust-steam from an engine, to keep the mine SUEciently damp to prevent the formation of dust clouds. Methods of preventing shots from blowing out; of using water cartridges to prevent flame ; and of using lime cartridges, wedges and other means of breaking down the coal were also discussed. Mr. Emerson Bainbridge referred to the explosive termed " roburite " (ammonium nitrate and

Jan 1, 1895

By F. F. Hintze

Petroleum production in the Rocky Mountain district during 1929 registered a small decline from that of the previous year, conforming with a gradual decrease in the amount of oil produced during the last few years. A number of causes may be mentioned to account for this result, chiefly overproduction in other regions and the apparent desire of operators in this territory to conform to the policy of proration and retrenchment adopted by special agreement among operators in many of the fields. Unit operation has been adopted to control oil production from the Sundance sands in the Salt Creek field, Wyoming, in line with the general effort to stabilize this phase of the industry and prevent excessive drilling of new wells. Another factor which greatly retarded development in the Rocky Mountain region was the executive order of President Hoover issued in March refusing the award of new prospecting permits to future applicants and threatening cancellation of all existing permits upon which actual drilling had not been done as specified by law. Only four states in the Rocky Mountain region are important oil producers. In 1929 Wyoming led with an average daily output of 52,600 bbl., followed by Montana, with 10,730 bbl.; Colorado, with 6500 bbl., and New Mexico with 2700 bbl. daily average. These states bear the following percentage relation to total production in the Rocky Mountain district: Wyoming, 72; Montana, 15; Colorado, 9; New Mexico, 4., (Table 1.) The total average daily production was approximately 73,000 bbl. and the total production of all four states during the year was 26,534,606 bbl. This is 2.7 per cent. of the total oil production of the United States during this period. Colorado Although Colorado is not a large producer of oil and natural gas, its oil operations are widely distributed over the state. The Florence field is one of the oldest oil fields in the country, and there are good reasons for believing that the state will retain its place for many years to

Jan 1, 1930

By Philip Derbyshire, Dale J. Scheffler

"Continuous Flight Auger (CFA) piling is a variation of Augered Cast-In-Place (ACIP) or augercast piling. In both cases a continuous auger with a hollow stem is used to drill a hole and a pile is formed by injection of cementitious material through the hollow stem as the auger is withdrawn. CFA differs from conventional American ACIP by the use of concrete rather than grout to form the pile, and by the type of equipment used to advance the auger into the ground and withdraw it. CFA installation uses a European style rig (i.e. fixed mast and rotary system) which can produce greater crowd and usually has a larger rotator or drill motor than the standard augercast setup. A standard augercast setup will consist of a lattice-boom crane and a set of leads to house the drill motor and auger. The auger size will range up to 24 inches (610mm). With CFA rigs larger diameter piles can be constructed, 24 to 36 in dia. (610mm to 915mm) are common and the technique has been applied with diameters up to 48-inch (1220mm). CFA makes use of sophisticated computer controlled monitoring systems, which have more recently been introduced for conventional ACIP piling. Developments in CFA have taken place over the last 25 years in Europe and particularly in the UK, but are relatively new in the USA. One application is in the construction of secant (overlapping) piled retaining walls. D.J. Scheffler Inc. recognized the potential of the CFA system following visits to the UK and has introduced its use into California for both secant piling and other applications.BACKGROUNDThe high price of real estate in many of the favored areas of California has increasingly led owners to want to build basements under their houses to increase the floor space available on a lot. Many of these areas are by the coast where the ground conditions are predominately granular and the water table is high. Conventional shoring and dewatering systems have often caused problems with adjoining properties. Clearly tangent walls are not suitable in these conditions because of leakage and loss of ground. The secant pile system, using CFA techniques, has proved very effective at overcoming the problems experienced by other methods. Other applications for CFA secant walls have included use for an emergency job on a highway following erosion caused by unusually heavy rainfall.METHODThe concept of secanting piles, whereby primary(female) piles are installed first and then secondary (male) piles are cut into the primary piles is not new. The method has been known for more than 30 years. Originally ‘Benoto’ grabbing rigs, developed in Japan, were used together with sectionalized double skinned casing and oscillators.This early method was slow, although very effective. More recently high torque rotary machines have been used. Contractors in the UK have increasingly used CFA techniques to further improve productivity of this type of piled wall. The improved capabilities of piling rigs available, as well as developments in concrete technology and instrumentation, have made this possible."

Jan 1, 2005

By Verya Nasri, Mehdi Bakhshi

"Fiber reinforcement has emerged as an alternative to steel bars in precast concrete segments due to advantages such as saving cost and reducing production time while developing a more robust product with improved handling and long-term durability. ACI recently drafted a new report as the first design guideline on FRC tunnel segments to provide specific guidance for this emerging technology. ACI document offers general information on the history of FRC precast segments from tunneling projects throughout the world; a procedure for structural analysis and design based on governing load cases, and a description of the material parameters, tests and analyses required to complete the design. This paper summarizes the design considerations in this ACI guideline prepared by the authors of this paper as the main contributors. Application of this guideline to design of a tunnel with an internal diameter of 5.5 m (18 ft) results in elimination of steel bars.INTRODUCTIONPrecast concrete segments are installed to support the tunnel excavation behind the Tunnel Boring Machine (TBM) in soft ground and weak rock applications. The TBM advances by thrusting off the completed rings of precast concrete segments that provide both the initial and final ground support as part of a one-pass lining system. These segments are typically designed to resist the permanent loads from the ground and groundwater as well as the temporary loads from production, transportation and construction. Tunnel segments are generally reinforced to resist the tensile stresses at both the Serviceability (SLS) and the Ultimate Limit States (ULS). With traditional rebar, a significant amount of labor is needed to assemble the cages and place the rebar, which results in higher production costs.Fiber Reinforced Concrete (FRC) can be used to enhance the production, handling, and placement of precast concrete segments. This is because of the uniform dispersion of fibers throughout the segment to include the concrete cover, which is very advantageous for resisting the bursting and spalling stresses. These stresses develop as a result of the high loads induced on the segments during the TBM jacking process. The presence of fiber in the concrete matrix helps mitigate against unintentional impact loads during segment handling and tunnel construction operations."

Jan 1, 2016

"Mining with blast holes drilled upwards may be done to recover sill pillars, or for economic reasons when the distance between the levels is relatively large. If the rock is sufficiently competent to accommodate large stope size, the distance between sublevels could be increased to as much as drilling accuracy allows. The same drill drift can be used for the drilling of both down holes and up holes. In the case of down holes, the initial opening of the stope (drop raise) is not as much a problem as for the inverse drop raise for mining with up holes. This is because, with a drop raise, a lot of space is available at the toe for the blasted rock to expand. In addition, the raise can be blasted in many shots, thus allowing smaller blasts each time. Inverse drop raises are generally much more difficult to blast because of the limited space for muck flow, and must, therefore, be taken down in a single blast, requiring special considerations in order to ensure a success. A case study of a 29 m (95 ft) inverse drop raise successfully blasted in a single shot at Heath Steele Mines is described. The paper covers technical considerations such as drilling accuracy, hole deviation survey, delay extension and protection, initiation methods and initiation sequence. Finally, a novel method for creating the initial opening called ’slot drilling’ is presented. This method, inspired from LKAB in Sweden, consists of drilling a row of interconnected holes using a special guide mounted on a regular production drill hammer.With a case study of blasting an inverse drop raise of 29 m (95 ft) in one blast, this paper further discusses some technical issues that are critical for the development of inverse drop raises. A novel method for creating the initial opening with a slot of interconnected holes is also presented with the experience acquired at different mine sites across the Noranda group."

Jan 1, 2000

The visitors to the October meeting will be given opportunity to visit the coal fields in Illinois, adjacent to St. Louis, the steam-shovel operations near Pittsburgh, Kan., and the Oklahoma oil fields. The coal mines of Illinois, Missouri, Kansas, Oklahoma and Arkansas furnish fuel over all of the central region of the country. Especially at this time, this district is of importance because of the necessity of producing enormous quantities to meet the country's demand. Some of the mines produce as much as 5,500 tons in 8 hr., and. the total output of Illinois, alone, in 1916, was 63,000,000 tons. Visitors may see elaborate underground electric tram systems, large underground machine repair shops, surface plants equipped for rapid loading, and some of the most modern coal-washing installations. The conditions for mining here are somewhat simpler than in the east.

Jan 8, 1917

By Ivette E. Torres

The final 26 tables of this chapter, tables 24-49, extend and expand the statistical series on production that was started in the 1963 edition of the Area Reports: International volume of the Minerals Yearbook and that was subsequently updated and expanded in the 1965 and 1967-90 editions. Mainly because of the separation of the countries that formed the U.S.S.R., the column that provided a 5-year average, was deleted. The listing order of major producers, however, continued to be, as in past years, in descending order of rank in the year of review, 1992. This group of tables now includes each of the top 19 crude minerals in 1983 in terms of value of their output plus 3 others of lesser rank. These 22 crude mineral commodities accounted for more than 98 % of the estimated value of world crude mineral production in 1983. Coal production, included in the 1983 value of production table as two separated entries, is combined in one table in this chapter. World output of five key downstream products-aluminum, steel, cement, nitrogen in ammonia, and refined oil-is included because of their significance as products.

Jan 1, 1994

By W. F. Hazen

This paper describing the mining practices at a 100 per cent mechanized mine working the Pittsburgh or No. 8 coal bed in eastern Ohio is one of a series being prepared by the U. S. Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The purpose of assembling this data is to place before those interested in the mining industry the methods employed and the cost data on the items involved in the winning of the coal and its removal to the railroad car at the tipple. Mining costs are governed by the mining method used, which is selected for its adaptability to local natural physical conditions such as the nature and thickness of the coal, its dip, the character of the roof and floor, and the thickness of the overlying strata.

Jan 1, 1929

By M. Kanda, W. D. Bensema, J. W. Adams

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in and above an operating coal mine, McElroy Mine, located near Moundsville, Nest Virginia. The electromagnetic environment created by 300 volt dc and 480 volt ac machinery was measured. In one technique noise was measured over the entire electromagnetic spectrum of interest for brief time periods. The noise was recorded using broadband analog magnetic tape. The noise data was later transformed to give spectral plots. In the other technique, noise amplitudes were recorded at several discrete frequencies for a sufficient length of time to provide amplitude probability distributions. The specific, measured results are given in a number of spectral plots and amplitude probability distribution plots.

Jan 6, 1974

By Davi Silva Braga, Alexssander Lopes Sampaio, Rodrigo Carneiro de Oliveira

Vallourec was world pioneer in the deployment, development and consolidation of technology for the use of pulverized charcoal as the main energy source on the first Grate-kiln pelletizing plant in Brazil. The objective of this work was to delve into the subject and to bring more information about this innovative practice of Vallourec that has been attracting the attention of other companies in the steel industry. Industrial tests confirmed the technical feasibility, taking Vallourec ahead in the project of adaptation and investment. With consolidated data of two years and five months from the beginning of the implementation, the main benefits are the average reduction of CO₂e emissions by 50%, cost reduction higher than expected and return on investment in just 19 months.

Oct 1, 2019

By Ian Farrell, Josh Stowe, Eric Wingeard

Tailings transport system design is generally based on identifying the minimum and maximum process boundary conditions for pump selection and pipeline sizing. The approach is robust and well-proven. However, the approach has the potential to skew selections to operating scenarios that have a very low likelihood of occurring, such as the combination of high solids throughput and low tailings solids concentration. The approach can result in a tailings transport system design that is overly conservative. A probabilistic method-based approach captures the independent variability of design inputs and the combined likelihood of outcomes. This approach identifies the process conditions that have the highest likelihood of occurrence and are most applicable to equipment and pipeline selections. An outline of a probabilistic-based approach to tailings transport system design and the resulting selections is provided in this article. The probabilistic-based system design is compared to the outcomes from the traditional approach. The benefits and challenges to this approach are discussed and recommendations for utilizing this approach for tailings transport system design are provided.

Mar 31, 2021

By Bradley Stoughton

AT THE meeting of the Board of Directors on May 20, the resignation of Bradley Stoughton as Secretary of the Institute was presented and regretfully accepted by the Board. The letter of resignation follows : Gentlemen: About two years ago, I indicated to the President and some members of the Board my belief that the office of Secretary of the Institute should not be a permanent one. It is my observation of events, not only in our own Institute, but also in several sister societies, that too long a tenure of office by the Secretary inevitably leads to a situation which is not good either for him or for the society. After submitting this in writing to the Directors on February 17, 1920, I was overpersuaded by members of the Board to defer resignation until a more convenient time for the

Jan 1, 1921

By E. A. Zawadzki

The problem of pollution of water by mine drainage is at least as old as the mining industry itself. However, research on the formation, composition, treatment, and abatement of mine water is a relatively recent historical event. At Bituminous Coal Research, Inc., acid mine drainage control has been an important area of work since 1944, at which time BCR began sponsorship of research at West Virginia University. The work at West Virginia University involved a detailed study of the acid mine drainage problem and led to the identification of iron oxidizing bacteria as important factors in the formation of acid mine water. The results of this research were summarized in 1954 by Temple and Koehler (1) who concluded that "no practical solution for the problem" of controlling acid mine drainage is yet known.?

Jan 1, 1967

By Jorge Agramonte Bermejo

Dado que el Perú es un pais rico en carbón antracítico y con limitados yacimientos de carbones semicoquizables, la tecnología que predominará para una producción mayoritaria será en relación con el consumo de la antracita en la industria de acero y de otras que le signifiquen ahorro de divisas y petróleo. En ese sentido, el objetivo del texto radica en hacer conocer la potencialidad de los yacimientos, cantidad, calidad de recursos y reservas de los mismos.

Nov 8, 1982