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Most people are familiar with Euclidean dimensions: zero for a point; one for a line; two for a plane; and three for a volume. Howeverbobjects are not actually Euclidean, but lie somewhere between Euclidean æend-membersÆ with a non-integer fractal (or æfractionalÆ) dimension. The fractal dimension D is a measure of the relative importance of large versus small. Consider the trace of a coastline on a map. It has a fractal dimension (1 =D =2) somewhere between a line (dimension = 1) and a plane (dimension = 2). The more tortuous the coastline, the higher the fractal dimension, and the closer it becomes towards a plane. The concepts of fractals and spatial geometry can be applied to a wide range of geologicaVmining problems as well as than those dealing with space. One commonly quoted fractal relation is the log-log relationship of ore-grade and tonnage. Until recently, we have never been able to define or measure spatial-geometry, but new developments in mathematics have provided a means by which to quantity and apply it to our problems.

Jan 1, 1992

By W. A. Rickelton

Trialkylphosphine sulphides, in contrast to their well known oxide analogues (1,2,3,4), have received comparatively little attention as metal extractants and previous studies have been biased toward analytical rather than commercial solvent extraction applications (5,6,7). The sulphides are soft Lewis bases and only from complexes readily with the limited number of metals in the periodic table which can be classified as soft acids (8) e.g. Ag+, Hg2+ and Pd2+. Consequently, these compounds tend to be more selective than the broad-spectrum, hard-base, phosphine oxide extractants such-as TOPO (trioctylphosphine oxide). The purpose of this paper is to describe a potential application of one phosphine sulphide, CYANEX® 471X extractant, in the selective recovery of silver from base metal sulphate solutions. CYANEX 471X is triisobutylphosphine sulphide (TIBPS).

Jan 1, 1984

This paper looks at the various stages of development of open stope drilling techniques. Due to the structural nature of the orebodies mined by open stoping it has been necessary to review mining methods. In-the-hole hammer drilling proved to be the solution to many problems encountered in horizontal percussion drilling.

Jan 1, 1977

By H. Ogasawara

Information on rock stress is important for safe mining in seismically active ground. On a major gold mine, a few tens of crews are continuously conducting geological drilling with small pneumatic machines. However, stress measurements are not often carried out in South African deep-level gold mines. One of the reasons is the drilling diameter that overcoring requires, which is much larger than the diameters used in regular geological drilling, e.g. Boart Longyear Metre Eater, which drills AQ or BQ holes. Larger diameter holes result in slower drilling advance, more load in transportation and handling at sites, and higher cost. In order to enable overcoring in BX size (60 mm diameter), we modified the compact conical-ended borehole overcoring (CCBO) technique that has been suggested by International Society for Rock Mechanics (ISRM) and was originally designed for NX drilling (76 mm diameter). With a single overcoring, the 3-D stress tensor can be determined. We tested this modified method at a depth of about 3 km at Moab Khotsong mine in South Africa. We worked with drilling crew who usually work at geological drilling with the Metre Eater. In January 2011, we tried using regular geological drilling tools (a sequence of a normal BX bit, reamer, and rod) without success. In August and September 2011, introducing stabilizers and thin BX bits, we succeeded. We could complete a cycle of procedures necessary for an overcoring, including shaping the borehole-end conically, glueing a 16-element strain cell, and overcoring, within 2.5 hours. Only 10 cm overcoring is needed, which increases the chance of successful overcoring in heavily fractured conditions. This modified method is suitable for up-dip holes to depths of 10-15 m from tunnels, and has the potential to be widely used at the initial stage of geological exploration drilling at many localities.

Jan 1, 2012

By Navid Hosseini

Several empirical equations to estimate coal pillar strength have been presented in academic studies. The development processes of these equations are similar and are usually obtained by fitting the mathematical function (curve) to field data. One of the best criteria to evaluate the quality of fitting for such equations is the correlation coefficient R2, which has limited applicability. It is necessary to calculate the correlation coefficient access to the initial data for which the equation is presented; this is impossible for many coal pillar strength formulas. This paper presents a new approach based on the analysis of uncertainty amplitude to compare the coal pillar strength. This approach utilizes a combination of parameters such as Mean Squared Error (MSE), Root Mean Squared Error (RMSE), function type and degrees of freedom. The confidence level of constants is subsequently formed and the correlation coefficient becomes more comprehensive. Therefore, for an effective comparison, the efficiency and accuracy of coal pillar strength formula can be used. Keywords: Coal Pillar Strength, Correlation Coefficient, MATLAB, Uncertainty Criterion

Jan 1, 2012

By Thorndycraftm R. B.

"PURPOSEThe purpose of this presentation to the Canadian Mineral Processors is to review gold heap leaching systems currently in use and discuss their applicability to Canadian ores. The author's experience with the development and operation of heap leaching spans the past four years at. Pinson, and visits to many ether heap leaches in the western United States.INTRODUCTIONBy way of introduction to the heap leaching system, I will describe in slight detail the method used at Pinson Mining in northern Nevada. This will be followed by a discussion of optional methods in use at other operations visited.The Pinson orebody is a finely disseminated, well-oxidized hydrothermal deposit. Gold particles are finer than 20- microns. The orezone hostrocks are metamorphosed and silici¬fied limestone and shale. Sulfides and carbonaceous materials are negligible.The Pinson open-pit mine has operated since June 1980. It produces 1500 tpd of C.I.P. mill feed averaging .10 oz gold per ton, and 1500 tpd of heap leach material averaging .025 oz gold per ton. Cutoff grades are 0.04 for mill feed, and 0.01 for heap leaching. Stripping ratio is 9 tons of waste and leach grade to 1 ton of mill feed.The project is located in northern Nevada at 4900 feet above sea level.,Winters are fairly severe, with freezing conditions affecting operations from early December through April. Although officially designated as ""high-mountain desert"" country, snow and/or freezing rain occur almost every week of the winter.To date, all Pinson production-scale heap leaching has treated run-90,000 tons of ore are stacked on 300 foot square clay leach pads. Cyanide leach solution is applied through ""wobbler"" sprinklers at .0025 gpm/sq ft for 60 to 90 days. The pregnant solution flows from the heap by gravity to plastic-lined ditches, into a collection sump and then through buried piping to the 2.2 million gallon pregnant solution pond."

Jan 1, 1984

By Hayes P. C, Matthew S. P

The product morphologies formed on the reduction of dense wustite crystals are classified into three types, A) porous iron, B) porous wustite covered with dense iron, and C) dense wustite covered with dense iron. The mechanisms of formation of these structures and the effects of impurity elements on the product morphologies are discussed.

Jan 1, 1985

By R. K. Mehta

An accurate, efficient and stable computation of the mill matrix function (eAt) is needed where mill matrix (A) is a real general matrix. Two important modeling cases in comminution where such need arises are: Heterogeneous comminution behavior of multi-component ores and ultra-fine grinding involving simultaneous attrition and fragmentation breakages. This paper presents the application of a novel splitting method in conjunction With similarity transformation technique in the form of "product formula" which is found to work in all cases and uses a most aggravating, yet interesting property of the matrix exponential in a restricted sense. Results are presented showing that this method can yield solution as accurate as those obtained With an analytical technique. The utility of this computational approach is demonstrated by parameter estimation analysis using a distributed component model in the liberation area through computer simulations.

Jan 1, 1992

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

CALCULATION OF MINE HEAD LOSSES FROM ALTIMETER SURVEY DATA USBM PENNSYLVANIA STATE UNIVERSITY - MINERAL ENGINEERING DEPARTMENT USBM USBM USBM THIS PROGRAM CALCULATES PRESSURE LOSSES USING THE USBM METHOD GIVEN USBM IN USBH IC 7809 BY MCELROY AND KINGERY.1957. THE MAJOR DIFFERENCE USBM BETWEEN THIS PROGRAM AND THE CITED REFERENCE IS THE TREATMENT OF AIR USBM

Jan 1, 1977

By E. A. Barrett, L. L. Rethi

Throughout all segments of the United States mining industry, 163 independent contractor employees were fatally injured between 1990 and 1997. Factors that contributed to these injuries were identified after reviewing descriptive information contained in Mine Safety and Health Administration fatality reports for each of the incidents. Thirty-three unique contributing factors were identified and multiple factors were noted for each fatality. Those most frequently discerned were "failure to follow `standard operating procedures"', (35% of the fatalities), "poor positioning of employee" (26% of the fatalities) and "failure to maintain equipment" (23% of the fatalities). Contributing factors were then associated with the accident and job classifications of the victims. Factors having the highest frequencies in the top five accident classifications where most fatalities occurred were as follows: powered haulage - "failure to maintain equipment"; machinery - "poor positioning of employee"; slip/fall of person - "inadequate fall protection" and "failure to wear safety line"; electrical - "equipment contact with power line"; and falling/rolling/sliding rock - "poor positioning of employee. " Among the job classifications in which most fatalities occurred, leading contributing factors were as follows: truck driver - "failure to follow standard operating procedures" and "poor positioning of employee"; laborer/utility man/pumper - "poor positioning of employee"; mechanic/ repairman and welder - "failure to follow standard operating procedures." Recommendations for utilizing contributing factor information as a basis for safety training are proposed. Training programs may be developed that inform independent contractor employees of factors which, in the past, have contributed to fatal injuries in their job classifications. Then, by combining this information with contributing factors identified in "related" accident classifications, a truly focused training intervention that addresses very specific workplace hazards may he developed.

Jan 1, 2002

By Frederick Laist

The ores received at the Washoe Smelter come almost entirely from the mines in Butte and contain the following minerals : Chalcocite, Cu2S; covellite, CuS; chalcopyrite, CuFeS2, (trace); bornite, Cu3FeS3; enargite, Cu3AsS4; malachite, Cu2CO4 + H2O (trace); pyrite, FeS2; sphalerite, ZnS; rhodo-chrosite, MnCO3, (less than 1 per cent.); rhodonite, MnSiO3, (less than I per cent.). The country-rock of Butte is of the granite family and is a quartz-monzonite containing a little less silica than typical granite. It is made up of the following rock-minerals in approximately the proportions indicated: Minerals. Composition. Per Cent. Quartz SiO2 20 Andesine 1/2 NaAlSi3O8; 4 CaAI2Si2O8 42 Orthoclase KA1Si308 23 Hornblende 1/2 Ca(MgFe)3Si4O12; & (MgFe)2(AlFe)4Si2O12 6 Biotite (HK)2(MgFe)2A12Si3O12 9 Titanite CaTiSiO5 0.1 Apatite (CaF)Ca4(PO4)3 0.05 Magnetite (FeO)(Fe2O3 0.15 Pyrite FeS2 0.02 99.32 The main country-rock (quartz-monzonite) is cut by dikes of aplite, a granite having the following composition: Quartz, 30; andesine, 20; orthoclase, 45; ferro-rnagnesian minerals, 3; pyrite, 0.1; total, 98.1 per cent. Closely associated with the copper-deposits are dikes and bodies of " Modoe" porphyry, technically known as quartz-

Jan 1, 1913

By H. C. Babbitt

The Effect of Arsenic.—A question involving the temperature of precipitation of ammonium phospho-molybdate, which was brought to my attention some time ago, led to the following experiment :*

Jan 1, 1893

In the Texas Panhandle 277 oil wells and 60 gas wells were completed during 1942, as compared with 647 oil and 52 gas wells completed in 1941. Fourteen dry holes were drilled in the Texas Panhandle in 1942, of which five were wildcats, resulting in four failures and one gas-field discovery in Sherman County; the latter being Hazy-Herrington-Marsh No. I Bivins completed for 5,600,000 cu. it. ol gas from 2989 to 3226 feet. During the year 1942 the Texas Panhandle produced, by counties, the following quantities of oil:

Jan 1, 1943

In the Texas Panhandle 277 oil wells and 60 gas wells were completed during 1942, as compared with 647 oil and 52 gas wells completed in 1941. Fourteen dry holes were drilled in the Texas Panhandle in 1942, of which five were wildcats, resulting in four failures and one gas-field discovery in Sherman County; the latter being Hazy-Herrington-Marsh No. I Bivins completed for 5,600,000 cu. it. ol gas from 2989 to 3226 feet. During the year 1942 the Texas Panhandle produced, by counties, the following quantities of oil:

Jan 1, 1943

While reaction to immediate demands may be required from time to time, the principal concerns of a Geological 'Survey should be proaction, with respect to the systematic production of maps, reports and data in order to meet exploration needs in the longer term, and interaction, which involves a complex matrix of relationships - firstly within the Department between disciplines and at various levels of responsibility, secondly with the exploration industry, thirdly with Commonwealth authorities particularly the Bureau of Mineral Resources (BMR), and fourthly with university researchers in related fields.

Jan 1, 1987

By Zhengbin Cheng, Wenguang Lu, Baoqi Sun, Jiaying Tang

This paper studied the flotation separation of feldspar, zircon and kyanite from quartz with a mixture of cationic and anionic collectors. Tests show that collector mixture has specially good effect, using it, the separation of these three silicate minerals from quartz can be successfully achieved at the natural pH value of tap water in the absence of any acid, fluoride and other inorganic reagents. The properties and characteristics of collector mixture were analysed. By means of IR-spectra, ESCA and AES, the action mechanism between collector mixture and minerals was throughoutly studied.

Jan 1, 1995

By M. Sciarone, B. Collins

The production, properties, and selection of ferrosilicon powders for heavy-medium separation by B. COLLlNS. B.Sc Eng. (Rand) (Fellow). T. J. NAPIER-MUNN. B.Sc. (Eng.). A.R.S.M. (Visitor). And M. SCIARONE. M.Se. Eng. (Delft) (Visitor). There are basically two types of ferrosilicon powder available to operators of heavy-medium plants in South Africa spherical and milled grades. The production processes are described, and the properties of the two types are examined and compared. Guidelines are given for the selection of the correct grade of ferrosilicon for any particular application.

Jan 12, 1974

By Ilmar J. Martens

The statistical information and cost data used in this report has been made available by NICKDATA INC. Since 1982, NICKDATA INC. of Toronto, Canada, has produced an annual comprehensive nickel industry cost study. Up to date information on 22 mines, 21 smelters, and 16 nickel refineries representing 30 nickel production operations in 17 countries are included in the computerized cost analysis. The report is compiled from information obtained through regular annual visits to major nickel operations and continuous monitoring of information on all nickel producers. The 1984 report which was completed this summer, reveals drastic changes in the nickel industry cost structures.

Jan 1, 1984

By Jeff Schwoebel, Dale Evans, Boyd Tangren

The Soldier Canyon Mine (the "Mine") degasification project demonstrates the ability to commercially recover coalbed gas to reduce overall mine costs associated with methane drainage. Gas is recovered from active and inactive areas of the Mine through an underground pipeline and surface compressors. Close inspection of gas quality is required due to potential contamination of air caused by excessive vacuum. Water must be removed routinely to enhance gas removal. This paper will review the operational and production procedures required to maximize gas recovery and insure safety at the Soldier Canyon Mine gas recovery project.

Jan 1, 1993

By E. G. Kelly, D. E. Walsh

The behavior of gold particles on a spiral was studied using radioactive gold tracers. The method allowed the effects of particle size, particle shape, pulp density, feed rate and splitter settings to be studied. Although the method has been successfully applied to other gravity concentrators, it was found that reliable results were more difficult to obtain on the spiral. However, these preliminary results show that, with suitable precautions, the technique is capable of providing valuable information, unobtainable from conventional studies, that could be used to better optimize spiral performance.

Jan 1, 1993