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By H. N. Herrick

THE flow characteristics of drilling muds, as described in this paper, and the method given for solving problems relating to the flow of these muds through pipe and accessory equipment, are based on a conception that drilling muds are plastic solids like paints or greases; not liquids. The data presented in this report have been obtained from studies of California muds, chiefly those used in the Kettleman Hills field, by the Producing Department of the Standard Oil Company of California. Although no claim of scientific exactness is made for the formulas and diagrams, since the data upon which they are based, are not. complete even for California muds, the method has proved to be a convenient means for estimating, closely enough for practical purposes, the pressures required to force muds at various rates through pipe systems in which they are handled. Certain approximations have been made to simplify the procedures so that they can be used easily in the field.

Jan 1, 1932

By J. Partyka, Trevor R. J. Kelly

This paper presents the results on noise testing of a fan only, as well as the results of a steel silencer and of flexible silencers that were connected directly to a fan. On-site facilities and free-field method set by the British Standards Institution were used to measure and then compare the fan only and different practical silencer configuration setups. In order to determine the fan-silencer combination that would give the maximum noise attenuation, total noise intensity, noise contributed to by the fan motor only, as well as aerodynamical noise created through air interacting with the fan parts were considered to obtain decibel readings for the octave bands. Subsequently, the optimal configuration found was the setup with flexible silencers on the fan inlet and the fan outlet. If only one silencer is used, it should be installed on the fan inlet. The aerodynamic noise affects the low frequencies. The flow noise is then overtaken at 1 kHz by the mechanical noise.

Jan 1, 1995

In recent years there have been a number of excellent towns built for mining communities in remote parts of Australia. Planning has been thorough, and very large capital expenditures have been made by companies to provide high standards of accommodation, services and amenities. But so often the phrase 'company town' comes to be applied, expressing the frustrations of the residents, working for a single employer who dominates their lives, and of the company, which would prefer not to have to build and operate a town. The much-vaunted early success of some iron ore, bauxite and coal projects has led to a belief that the success of all mining projects is assured. Those holding this belief ignore the vagaries of mineral deposits and of markets, and the need to amortise large high-risk capital expenditures, much of which is spent on social and industrial infrastruc- ture. This expenditure on infrastructure does not have to be

Jan 1, 1975

The National Institute of Occupational Safety and Health has classified diesel exhaust as a potential human carcinogen. Though standards for diesel particulate matter (DPM) in the work place have not been established, concern for the health of miners is prompting mine operators to consider methods for reducing worker exposure to diesel exhaust. Approach One of many methods for reducing DPM being investigated by the Bureau of Mines is the use of additives in diesel fuel to improve combustion. Research Results Three fuel additives have been tested in Caterpillar and Deutz diesel engines which are similar to types used in underground mines. One iron-based additive containing ferrous picrate had no effect on emissions. A second iron-based additive containing ferrocene reduced DPM between 5 and 45 pet depending on engine operating conditions. The 37-pct reduction for an 8-minute duty cycle, which includes a wide range of transient loads and speeds, is considered to represent in-mine performance.

Jan 1, 1990

By Charles D. Hoyt

T IME studies and cost accounting were combined to increase the efficiency of the overall mining method and thereby reduce costs at the Titania mine of the National Lead Co. in southern Norway about 70 miles southeast of Stavanger. From these studies a more effective drilling system was developed, standards were adopted for setting base pay rates, shrinkage stoping was abandoned for open stoping, a new mechanical loading chute was adopted, and the loading and haulage system was changed. Ore minerals at the Titania mine are ilmenite and magnetite; gangue minerals are plagioclase and hyperstene with accessory minerals of biotite, pyrite, chalcopyrite, and spinel. The average content of the ore is 17 pct TiO2 and from 20 to 25 pct iron. The ilmenite crystals contain microscopic lamels of hematite, making it impossible to obtain a high TiO2 content in the concentrate. An ilmenite concentrate with 44 pct TiO2 and 36 pct Fe, and a magnetite concen-

Jan 9, 1950

By Robert A. Haney

Utilizing the recently developed laser velocimeter and a Pitot-static tube, the United States National Bureau of Standards (NBS), has calibrated various types of anemometers that are commonly used in the mining industry. This paper presents a summary of the performance characteristics including accuracy, precision, starting and stopping speeds of each instrument tested. The specific instruments that were calibrated by NBS have become Mine Safety and Health Administration (MSHA) primary reference instruments. These primary reference instruments are used in turn to calibrate secondary reference instruments for each Coal Mine Safety and Health District. Each District calibrates anemometers that are used by District engineers and inspectors. Calibration is accomplished through a substitution procedure in which the reading on the anemometer is compared to the true velocity determined by the reference instrument. Calibration is performed over the entire range of the instrument using an open jet wind tunnel to produce the various approximate velocities. Some specific details of the calibration procedure are presented in this paper.

Jan 1, 1980

By Ta M. Li

In Gila County, Ariz., the Jaquays Mining Co. still finds the mining of asbestos a worthwhile and economical venture. At a time when domestic productive capacity is being reduced because of rapidly rising costs and tough environmental dust standards, this firm has dramatically brought its mine and mill operation into full productive capacity and compliance with both Federal and State regulations. Jaquay's Mining Corp. owns four underground mines in the Tonto National Forest, located approximately 32 miles north of the Globe-Miami District in Arizona. Only one mine, the El Dorado, is presently active. It mines an estimated 45,000 tpy of ore and waste. From this figure about 3000 tpy of fiber (No. one crude to Grade 4T) and fiberized shorts (No, seven) are recovered at the firm's mill, located in Globe, Ariz. Based on current ore reserves, the El Dorado mine has an estimated life between 15 to 17 years, assuming current mining rates and stable market conditions.

Jan 3, 1975

By Glenn Southward

This describes a highly concentrated mining system consisting of a series of short faces arranged to get complete recovery of coal with the maximum protection for the men and equipment. A series of conveyors collect the coal from eight faces and discharge into mine cars at a central loading point on a main haulageway. The conveyor is sectional and, by a multiple-drive arrangement, the same standard parts are used to construct a unit of any length. THE. V system of mining used at the Norton mine of West Virginia Coal & Coke Co. was designed as a modified longwall with face conveyors, FIG. 1.-GENERAL DESIGN AND ARRANGEMENT OF FACES IN V SYSTEM. for use under roof conditions that would not permit regular longwall methods. This mine is in the Lower Kittanning seam, which averages about 6 ft. in height. There is from 20 to 30 ft. of slate and shale immedi-

Jan 2, 1924

By E. D. Attanasi

Exploration for non-fuel minerals has declined since 1988 as recessionary pressures have slowed growth in the industrialized economies. By most accounts, however, 1990 expenditures were still significantly greater than the low levels experienced in the mid-1980s. The Persian Gulf crisis introduced instability in energy prices and greater uncertainty into an already cloudy economic picture. As 1990 unfolded, the US savings and loan problems spread to the commercial banking system, leading to the failure of several major US commercial banks. The Japanese stock market also suffered significant losses as Japan's Central Bank raised interest rates. The Soviet Union experienced shortages of food and other basic items. Its government faces resistance to changes leading to a market economy. Individual Soviet republics also are seeking more control of their own destiny. The cost of German reunification, in terms of the capital required to bring the east's infrastructure and industrial base to western standards, also appears to have been underestimated.

Jan 1, 1991

[Adams, Douglas K General Electric Co., P.O. Box 2331, Denver 1, Colo. Adams, Kenneth L Peabody Coal Co., 301 N. Memorial Dr., St. Louis, Mo. 63102 Ahlborg, William Joy Mfg. Co., 1400 17th St., Denver, Colo. Allen, Dr. Harry C U. S. Bureau of Mines, Washington, D. C. 20242 Anderson, Robert Mine Safety Appliances Co., 1881 West N. Temple, Salt Lake City, Utah Archer, Bryan J., Jr Peabody Coal Co., 421 Glenwood St., Grand Junction, Colo. Arentzen, E. M W. RD 1, Charleroi, Pa. Arentzen, L. E. Lee-Norse Co., 6030 55th Pl., Arvada, Colo. Arentzen, Rolf F Lee-Norse Co., Box 582, Charleroi, Pa. Arnston, E. K Standard Oil Div. American Oil, Rt. 1, Box 504, Golden, Colo. Artis, Cliff E Big Horn Coal Co., 247 Sherman Ave., Sheridan, Wyo. Atchison, Lee Atchison Construction Co., Drawer D, Aztec, N. Mex. Audin, Clement, Jr Champion Coal Mining Co., Paonia, Colo.]

Jan 1, 1969

By Thomas F. Kerr

The La Quinua mill at the Yanacocha mine in Peru has a thickened tailings storage facility that is contained entirely within an active heap leach pad. In this respect, it is unique and unprecedented in the mining industry and provides the operator, Minera Yanacocha S.R.L. (MYRSL), with certain cost, land-use and closure efficiencies. The combined design requires that the leach ore embankments retaining the tailings provide the same high level of stability and security required of major tailings dams. Contrary to standard tailings dam construction, the leach ore in these embankments is placed in thick, uncompacted lifts so that they maintain adequate permeability for leaching. The resultant loose structure makes static and dynamic liquefaction a critical issue, and the key design principle for avoiding a liquefaction related failure is to keep the ore that is saturated or very near saturated when under leach well removed from the outer faces of the embankments and contained behind large unsaturated structural shells.

Sep 14, 2009

By Cathleen J. Webb, Arden D. Davis

Begun in 1992, an abandoned and inactive mine inventory in the Black Hills National Forest has resulted in a hazard ranking of the most severely affected sites. For purposes of the inventory, the Black Hills were divided into three main regions: the northern Black Hills, with primarily gold mines; the central Black Hills, with pegmatite mines and some gold mines; and the southern Black Hills, with primarily uranium mines. A computerized data base has been developed along with standard forms for field crews. The forms were designed to provide maximum compatibility with other abandoned mine inventories on various federal and state lands. Measures recommended for the most hazardous and heavily affected sites include regrading of unstable slopes, fencing of open shafts, and remediation of the most severe acidic mine drainage problems. Specific examples are illustrated where remediation and safety measures were recommended or have been implemented. The vast majority of the sites, however, needed little or no remedial action.

Jan 1, 1995

By Dawson RD

For the past 45 years, the casting of refined lead ingots by The Broken Hill Asso- ciated Smelters Pty. Ltd. (B.H.A,S,) at Port Pirie has been mainly by use of manually operated rotary casting wheels of Newnam design. This style of operation was quite satisfactory as far as standard of product was concerned, but was manually intensive and a relatively high cost operation. With most other large scale lead producers already using automated-casting equipment, an investigation which commenced in 1966, progressed through stages of enquiry, design and development until the present plant commenced trial operations in late 1973, and fully operative in late 1974. While certain features of the plant are sed on overseas practices the plant was signed and built within Australia to BRAS ecifications. As constructed it consists two almost identical casting lines each pable of producing 25 kg ingots at 25 tonnes r hour using straight line casting machines d automated stacking weighing and strapping

Jan 1, 1975

By R Milton, D Hake, H Sprague

The North Western Sewer tunnel extends over 11.5 km in the North Western suburbs of Melbourne.The $253 million tunnel project provides a critical link in the Melbourne Sewer Network. The existing sewers fail to service the increasing demands of the growing population of the North West regions of Melbourne. This project will protect the environment and improve the standards of service of the existing system. This paper concentrates on Section three of this project, consisting of the final 4 km of the Contract, three access shafts and a cut and cover section of tunnel.Transfield Tunnelling as Head Contractor constructed the tunnel for Melbourne Water Corporation, with Enetech Streamline, formally Streamline Australia, a trading arm of Melbourne Water acting as Superintendent.Excavation of Section three of this project commenced in September 1994 and project completion is scheduled for October 1998. The tunnel passes below the residential suburb of Essendon, through some of the most challenging ground conditions ever attempted to be tunnelled in Australia.

Jan 1, 1999

By Ronald J. Roman

The shrinking core model for coarse particle leaching has been generally accepted as describing the leaching of a copper oxide or sulfide ore. However, when a mixed oxide/sulfide ore-is leached this model can not be used in its simple form because at least two and possibly three separate leaching processes are occurring simultaneously (dissolution of oxide copper minerals, secondary copper minerals and primarily copper minerals). It has been impossible to isolate their individual leaching curves from the recovery/time curve generated by the column leach test. This paper describes a tests program carried out at the Groupo Mexico, Mexicana de Cobre's La Caridad operation in which the individual recovery/time curves for the leaching of copper oxide mineral, secondary copper mineral and primary copper minerals were developed from standard column leach tests. Once the individual recovery/time curves were developed scale-up of the column leach test results to the commercial heap leaching operation is possible by using the shrinking core model.

Jan 1, 1999

By L. W. Bahney

Many methods for the determination of gold or silver, or both, in cyanide solutions have been published, which with care in manipulation, and modification in some cases, will give results that are satisfactory. It is possible to classify or group these methods as follows: 1. Evaporating the solution in a porcelain or agate-ware dish containing litharge,l or in a "boat" made of lead foil. 2. Forming a lead sponge containing the precious metals by means of zinc shavings,2 zinc dust,3 or a piece of aluminum.4 3. Decomposing the cyanide solution with an acid and precipitating the precious metals by the use of one or a combination of some of the following: Copper sulphate,5 sodium sulphite,6 hydrogen sulphide,' cement copper.ll 4. Precipitating the silver by zinc dust held in a Gooch crucible and determination with a standard solution of sulphocyanate.9 5. Electrolysis.l0 . 6. Colorimetry.ll

Jan 1, 1915

By V. F. Swanson

A mathematical model is presented which allows the free or hindered settling velocity to he calculated for any size or- shape particle in any fluid, and at any percent solids up to the maximum. The validity of the model is supported by comparing calculated velocities (or viscosities) with measured values for 1073 data points contained in 80 sets of data encompassing a range of Reynolds’ numbers, from 0.002 to 770.000. The average error was 0.69%, with an average standard deviation of 6.65%. The derivation of the model is too lengthy to include in this paper, which will specifically present the application of the model to the free settling of minerals and spheres, prediction of the friction factor in wind tunnel tests, the viscosity of suspensions of spheres, the hindered settling of mono-sized spheres and closely sized minerals, and the settling of large spheres in suspensions of small spheres.

Jan 1, 1990

Provide sound battery safety guidelines for mine workers who maintain mobile surface mining equipment. Approach Battery-related accidents account for about 5 percent of all nonfatal disabling injuries in coal and metal nonmetal surface mines. These accidents occur despite the fact that appropriate battery safety technology (maintenance-free batteries, cable removers, fault detectors, hot-jumping systems, etc.) exists. Mine operators are not always aware of the safety measures that could be taken because this safety information is widely scattered in numerous unrelated technical reports, vendor brochures, and journal articles. A literature search of these reports and a review of relevant industry standards, handbooks, and references on battery safety, followed by discussions with mining company and MSHA personnel, provided the Bureau of Mines with the background necessary to develop procedures for proper and safe battery usage. These procedures were condensed and written in nontechnical language to serve as guidelines in assuring battery safety during maintenance of mining equipment.

Jan 1, 1986

By Seth C. Schaefer

The Bureau of Mines studied thermodynamic properties of Al-Ni alloys con¬taining 0.54 to 30.04 atomic percent nickel with the aid of the high-temperature galvanic cell Al(1) // Al+3 (AlCl3 in NaCI.KC1) // Al-Ni alloy (1 or s). Activities of aluminum and nickel (compared with pure liquid metals as the standard state) show pronounced negative deviation from Raoult's law at 1,273 K. The properties [?G, ?Gxs, ?G ideal, ?GA1, AGxs1, ?Gni , and ?GNixs] have been derived from the experimental data and are summarized in tables and illustrations. At 1,127 K, the thermodynamic stability for the invariant three-phase equilibrium consisting of a saturated liquid, A13Ni, and A13Ni2 has been uniquely defined by an activity for aluminum of 0.751. A free energy of formation at 1,127 K of -7,940 cal/g-atom was derived for the compound A13Ni.

Jan 1, 1975

Simple quotation of quantities of coal reserves neglects the relationship between qualities of coals and their efficient use. If exploitation of a deposit is contemplated, its life expectancy can be deduced only if its reserves are estimated according to the coal user's technological standards. A wide range in properties will satisfy a steaming coal, whereas a high vitrinite high rank coal would be preferred for coking and a low inertinite low rank coal for conversion. In competitive trading the buyer's commercial specification may require weighing against the producer's practical ideals, especially when beneficiation is critical. Differentiation of grades in quality of a deposit provides an intelligent understanding of the economic importance of the deposit. The Wongawilli seam of the New South Wales Southern Coalfield exemplifies the effect of quality criteria upon the extent of in situ, recoverable and marketable classes of economic reserves. Effective management of a deposit will result from simultaneous quotation of coal qualities and quantities in a statement of its reserves.

Jan 1, 1979