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By J. R. Campbell

It is the purpose of this paper to review somewhat in detail the literature on the subject that is extant, which ought to provoke considerable beneficial discussion. The value of 1 per cent. ash in blast-furnace practice was brought to the attention of the writer when he was connected with the U. S. Steel Corpn. Various groups of blast furnaces in the Pittsburgh district compiled a statement in which the average saving was about 6 c. per ton on pig iron for every 1 per cent. of ash reduction. Later, the same groups of furnaces, when materials had reached a higher price, compiled a statement in which there was a 30-cent saving on pig iron for every 4 per cent. ash reduction in the Pittsburgh district, which was equivalent to 7½ c. for every 1 per cent. ash reduction. In the Chicago district, on long freight hauls of coal and coke from the Pocahontas district, the set-up was 30 c. per ton of pig iron for every 2 per cent. ash reduction, or 15 c. for every 1 per cent. Some years ago, Ralph H. Sweetser, of the American Rolling Mill Co., presented a paper which provoked considerable comment.' To get the matter again before this body a résumé of his computations is given below: Comparison of Pig Iron Costs Ash in Coal. Ash in CoKe, Fixed Carbon in Coke peR Ton OB PIG Iron peN Day, Per Cent. PeR CeNt. Coke. Per Cent. PIG IRon. Lb. Tons 6.00 8.70 89.80 1800 365.0 7.00 10.15 88.35 1860 353.2 Coke with 8.70 Per Cent. Ash Ore mixture, 4144 It). = 1.85 tons @ $5.50.............................. $10.17 Coke, 1800 lb. = 0.90 ton @ $6.50..................................... 5.85 Limestone, 1000 lb. = 0.50 ton @ $1.50................................. 0.75 Labor, $365 per day on 365 tons....................................... 1.00 Supplies and service, $250 per day...................................... 0.68 Overhead, $200 per day............................................... 0.55 Reserve for relining and depreciation................................... 1.00 Total............................................................. $20.00

Jan 1, 1931

By J. C. Vreugdenburg, B. A. Dippenaar, J. Muller, T. L. de Vries

Iron ore fines are agglomerated in the sintering process to produce sinter: an important feed material for blast furnaces worldwide. A model of the iron ore sintering process has been developed with the objective of being representative of the sinter pot test, the standard laboratory process in which the behaviour of specific sinter feed mixtures is evaluated. The model aims to predict sinter quality, including chemical quality and physical strength, as well as key sinter process performance parameters such as production rate and fuel consumption rate. The model uses the finite difference method (FDM) to solve heat and mass distributions within the sinter pot over the sinter bed height and time dimensions. This method can further be used for establishing empirical relationships with measured sinter properties. Inputs into the model include the feed material physical properties, chemical compositions, and boundary conditions that vary over time. Sub-models describe relationships between applied pressure differential and gas flow rate through the bed of granulated fine ore particles, combustion of carbonaceous material, calcination of fluxes, evaporation and condensation of water, and melting and solidification. Four sinter pot tests were performed and the model predictions validated against temperatures measured at depths of 100, 230, and 420 mm. Differences between predicted and measured temperatures indicated the need for optimization of some model parameters that are uncertain. Optimization resulted in an improvement in the correlation between the predicted and measured temperatures for all tests, although an acceptable level of agreement was not achieved in all cases. Using these parameter values, reasonable agreement was found in terms of typical performance parameters for three out of the four tests.

Jan 1, 2014

By J. Satur

In copper mineral processing, pyrite coexisting with copper sulfide minerals like chalcopyrite is separated by flotation as tailings and its oxidation in tailing dams causes the formation of acid mine drainage. This paper proposes carriermicroencapsulation (CME) as a new method for suppressing pyrite flotability, as well as its oxidation. In this method, an organic carrier combined with Ti is used to form a thin Ti02 layer on pyrite, which gives a hydrophilic property and acts as a protective coating against oxidation. To form the coating, a ground pyrite sample was treated with Ti-catechol complex solution under various conditions. Bubble pick-up experiments and flotation experiments showed that the treatment of pyrite with Ticatechol complex changed the hydrophobic nature of pyrite into hydrophilic even in the presence of xanthate as a flotation collector. Oxidation testing of the CME-treated pyrite by 0.02 kmol m-3 HN03 showed that Fe release was suppressed by the CME treatment with respect to the control. This is assumed to be due to the formation of Ti02 coating on the pyrite surface. The effect of CME treatment on chalcopyrite wettability is also discussed.

Jan 1, 2007

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. This paper i8 a continuation of a series made in cooperation with the Coordinating Fuel Research (CFR) Committee of the Coordinating Research Council (CRC), Inc. The first of this series of reports presented data on motor gasolines sold during the winter of 1935-36, and succeeding reports described motor gasolines Bold during the summers and winters to and including the summer of 1941 Y. No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed.

Jan 1, 1951

By Brian Wingfield, Rick Givens, Greg Williams

Many technological advancements have been made in explosive products and applications over the last 15 years resulting in productivity and cost gains. However, the applications of total energy (engine horsepower) in the majority of rotary drilling technology, has remained virtually unchanged over that period. While advancements have been made in components, efficiency, and types of hydraulic systems used on drills, the application of current hydraulic technology to improve drilling productivity has not been interactive with end users. This paper will investigate how traditional design assumptions, regarding typical application of horsepower in current rotary drill systems, can actually limit productivity.

Jan 1, 1996

By L. C. McCabe

This paper is a progress report on a study of the distribution of the banded ingredients (Figs. 1 and 2) in Illinois screenings and the method of determining their distribution. Proximate analyses and screen tests1 have been reported and a further report on the washability characteristics of the screenings is in preparation. The microscopic study of the screenings is not yet far enough advanced to permit a conclusive report on the effect of mining, screening and washing on the distribution of the banded ingredients in the coals of Illinois. However, considerable fundamental data have been collected as a background for the screenings investigation and for a proposed study of fuels composed of known quantities of vitrain, clarain and fusain, the three common banded ingredients of Illinois coals. These fundamental data and the preliminary information now available from the microscopic study of screenings are broadly indicative of the reaction of the coals to the physical processes affecting them in mining and preparation. Proximate analyses of samples of vitrain, clarain, and fusain from several Illinois mines have been published2, but those given in Table 1 serve to show the differences that are apparent in proximate analyses. The vitrain samples are consistently low in ash, and the unit-coal value is uniformly lower than in clarain. The average fuel ratio (F.C./V.M.) of the vitrain samples in the table is 1.57 whereas the clarain average is 1.42. The fusain analyses vary considerably in ash and moisture. In the two samples from this mine the moisture values range from 8.99 to 22.80 and the ash from 4.86 to 16.91 per cent. Fusain has higher fixed carbon than either vitrain or clarain but the percentage is erratic from sample to sample. The relative proportions of the banded ingredients in the Herrin (No. 6) coal in Illinois is reasonably well known but detailed information

Jan 1, 1936

By L. C. McCabe

This paper is a progress report on a study of the distribution of the banded ingredients (Figs. 1 and 2) in Illinois screenings and the method of determining their distribution. Proximate analyses and screen tests1 have been reported and a further report on the washability characteristics of the screenings is in preparation. The microscopic study of the screenings is not yet far enough advanced to permit a conclusive report on the effect of mining, screening and washing on the distribution of the banded ingredients in the coals of Illinois. However, considerable fundamental data have been collected as a background for the screenings investigation and for a proposed study of fuels composed of known quantities of vitrain, clarain and fusain, the three common banded ingredients of Illinois coals. These fundamental data and the preliminary information now available from the microscopic study of screenings are broadly indicative of the reaction of the coals to the physical processes affecting them in mining and preparation. Proximate analyses of samples of vitrain, clarain, and fusain from several Illinois mines have been published2, but those given in Table 1 serve to show the differences that are apparent in proximate analyses. The vitrain samples are consistently low in ash, and the unit-coal value is uniformly lower than in clarain. The average fuel ratio (F.C./V.M.) of the vitrain samples in the table is 1.57 whereas the clarain average is 1.42. The fusain analyses vary considerably in ash and moisture. In the two samples from this mine the moisture values range from 8.99 to 22.80 and the ash from 4.86 to 16.91 per cent. Fusain has higher fixed carbon than either vitrain or clarain but the percentage is erratic from sample to sample. The relative proportions of the banded ingredients in the Herrin (No. 6) coal in Illinois is reasonably well known but detailed information

Jan 1, 1936

By George Burke

Of the three projects, particularly the extensive Nimitz II (downtown) project, a single system, which was part of the operation, was used to control the spoil. Spoil control was continuous with the work since a vacuum truck and crew was used to suck up the spoils as they came out of the borehole. So, the whole job was kept clean both during operations and at the end of the shifts. On the Sand Island project, a double system was used. Larger spoil quantities were contained within the shaft limits during the work and the cleanup or disposal of the spoils was performed during excavation.

Feb 10, 2003

By Meyer Klein

Decision theory is the formal theory of the logic of decisions in view of the decision maker's objectives, preferences, I beliefs, and available information, It usually deals with weighty economic problems involving irrevocable (or costly to reverse) decisions. Capital investment planning problems constitute an instance par excellence for application of the decision theory concepts. Decision theory as it is presently conceived has evolved in recent years. At first it concentrated on decisions in the face of total lack of information and on games with intelligent adversaries. The results of these efforts proved theoretically interesting, but practically of little applicability. In the last few years, stress has shifted to the introduction of subjective probabilities and preferences, and the results have been eminently successful in applications both in government and with- in business firms in the resolution of complex problems.

Jan 1, 1970

By H. D. B. Wilson, D. T. Anderson

"Canadian sulphide deposits generally have characteristic compositions. Metal associations in ore deposits and in igneous rocks are similar.Nickel: sulphur ratios, copper-nickel ratios, and nickel :cobalt ratios in copper-nickel sulphide ores are characteristic for most orebodies. Nickel, as sulphide, is highest in ores associated with ultrabasic rocks, whereas copper is highest in ores associated with gabbros. Cobalt is relatively constant. The metal ratios in copper-nickel ores are due, first, to the composition of the related igneous rock or magma; second, to the partition ratios of the metals into the sulphides when separating from the silicate rock or magma; and third, to the conditions at the time of deposition. Each factor is discussed and the evidence indicates the Frood orebody is a magmatic segregation in place and Falconbridge is an injected sulphide melt. Many Canadian orebodies containing copper, zinc, or lead also have relatively constant compositions. •Copper and zinc are concentrated in gabbro and diorite, and copper-zinc ores in northwestern Quebec are spatially related to gabbros and diorites. The same three factors con-trolling metal ratios in. copper-nickel deposits should control the metal ratios in copper-zinc deposits if the metals come from the gabbro-diorite intrusions.The ratios of base metals in common sedimentary rocks are not similar to the ratios in orebodies. Base metal elements are mobilized during high-grade metamorphism, but much fundamental research is needed before the relation between metamorphism and ore deposits can be established on a sound basis. The distribution of elements in sulphide orebodies suggests that cop-per, zinc, and lead are deposited simultaneously .in relatively constant proportions rather than successively in a paragenetic sequence. Zoning may be due to different ratios of metals being deposited under changing temperature, pressure, and chemical environment, or may be the result of other processes."

Jan 1, 1959

By John J. Friel

The addition of dolomite to iron ore pellets improves their high-temperature reduction properties primarily by increasing their reducibility and raising their softening temperature. In this study we prepared dolomite-fluxed pellets from three different concentrates; Hibbing, a magnetic taconite, Knob Lake, an earthy hematite; and Carol Lake, a mixture of specular hematite with magnetite. The composition n of the concentrates is given in Table I. The pellets were subjected to standard physical tests and the following reduction tests: low temperature degradation, swelling, softening, and thermogravimetric analysis. Petrographic examination and electron microprobe analysis allowed us to evaluate the effect of composition and firing on the phase assemblage. Further, we were able to interpret the test results in terms of chemistry and microstructure. This approach enabled us to determine which fluxed composition best suited each of the concentrates.

Jan 1, 1980

By Susumu Ukita

We have developed first a conveyor belt for transporting large lumps, i.e. Rock Belt successfully, in June 1976. The First Rock Belt had been delivered to Myodani site of Kobe City Developing Board in Japan, and its' successful operation has attract keen interests in customers from over the world as well as Japan. However, this First Rock Belt was removed in arch '81, viewing it has satisfactory expired its service life of about five-year, and also original location of this belt become to be far from the site due to long-years earth collecting work. Taking this opportunity, we introduce the Second Rock Belt applied for Rock Belt Loader as ell as three types of application of our Rock Belt working for rationalization of quarry of major company in Japan, and, view the prospect of Rock Belt:

Jan 1, 1981

Selection of mining methods, stope dimensions and stoping sequences is usually based on comparisons with other similar orebodies or rocktypes. Rock mechanics principles assist the process, which can be further improved by application of rock mechanics' models - in particular, computer based stress analysis techniques. These models vary in capabilities and potential application but, basically, can be subdivided into techniques which only model the surface of excavations, and those which model the total volume to be analysed. To address the wide range of geometries, stoping methods and sequences, and geomechanical environments at Mount Isa Mines, a number of models have been developed. By presenting examples of their actual and potential application it is demonstrated that appropriate use of these techniques will assist in the determination of mining parameters and improve ore recovery. Examples presented cover sequencing in tabular and massive orebodies, location of shafts and shaft pillars, and backfill and hanging-wall stability. It is concluded that surface techniques are more appropriate for regional analyses and volume techniques are more suited to analyses of detailed, local geometry. Colour computer graphics should be an integral part of data preparation, and results interpretation and Presentation.

Jan 1, 1986

By R. Perez

The consumption of grinding media forms a significant part of the operating cost of a mineral processing plant. An estimated half billion pounds of steel in the USA and over one billion pounds in the world are consumed each year in wet grinding alone. However, there is some conjecture as to the interacting roles of abrasion and corrosion. In order to provide a more complete picture of the conjoint action of abrasion and corrosion, marked ball tests were conducted on different grinding ball compositions in a laboratory ball mill and the metal losses were measured on varying the conditions, i.e., pH, PO2, in wet grinding a Cu-Ni gabbroic rock and compared with taconite grinding. Ball wear rates ere discussed with respect to ball composition and microstructure and the varying conditions used in the grinding tests.

Jan 1, 1984

By W. E. Hale

The Institute of Applied Geology (I.A.G.), a joint project sponsored by the University of the Philippines, the Philippine Bureau of Mines and the United Nations Development Programme (Special Fund) undertook during 1965-66 a number of field projects in Northern Luzon Island (Fig. 1). These field operations were of a two-fold nature: during approximately six weeks an orientation survey, involving, geology, geophysical surveying, and geochemical prospecting, was conducted over a partly developed, disseminated copper deposit at Sto. Nino (Fig. 1). The Sto. Nino study demonstrated (Hale and Govett, 19677 Govett and Hale, 1967) the feasibility of geochemical prospecting relative to other exploration methods for the location and delineation of disseminated copper occurrences, the major source of metal in the expanding mineral industry of the Philippines. A vein occurrence at Suyoc (Fig. 1) was similarly subjected to

Jan 1, 1968

By David S. Young

All pigments and extenders or fillers whether organic or inorganic fall into the following broad general classes: I. Colored II.-White III. Black IV. Metallic A pigment- is any particulate matter that is essentially insoluble and chemically unaffected by the media into which it is dispersed. According to this very broad definition, colored pigments, white pigments, fillers, extenders, and functional pigments would all be included. The particulate size range would also be quite broad ranging from very fine colloidal particles (~0.01µ) to relatively coarse particles (~100.0µ). This broad definition is usually subdivided into more practical divisions which tend to relate the classification of the pigment to its primary function in the system in which it is used. Hence, the word extender implies that its major purpose may be to extend the system.

Jan 1, 1985

By P. M. Lin

This paper presents an overall stabilization method to eliminate the potential of reoccurrence of subsidence over abandoned mine lands. The method considers column grouting at the specific locations inside the subsidence influence areas including the distressed and stress concentration zones instead of grouting' around and beneath the damaged structures. The later method is commonly used for AML subsidence abatement at the present. By using finite element method the conditions of stress distribution in the strata before and after grouting can be calculated. The design of grout pattern includes the location and number of the grouting holes. Based on the calculation, the proposed method significantly reduces the stress concentration, i.e., the potential of reoccurrence of subsidence can be reduced or eliminated. A comparative analysis including number of grouting holes, grout affected area, stress level, and potential of subsidence reoccurrence will also be presented.

Jan 1, 1990

By A. Perry Thompson

I. GENERAL DISTRIBUTIONS APPEARANCE, AND RELATIONS MINING in Butte has seldom encountered covellite in commercial quantities. The notable occurrences, extending vertically and laterally perhaps several hundred feet, presented scattered, bladed lenses of this mineral in a matrix of quartz, pyrite, enargite, bornite, and chalcocite. But under the microscope covellite is seen to be widespread in the Butte ores, though in such small quantity that megascopic examination will not discover it. In early mining operations covellite was found in the Gray Rock vein, a member of the Blue vein system. As described by Sales,1 it persisted as an occasional ore mineral, associated with quartz, pyrite, tetrahedrite, bornite, chalcocite, and minor amounts of sphalerite, from the 700-ft. to the 1,200-ft. level of the East Gray Rock and Diamond mines. Crushed quartz-monzonite and later quartz completed the vein filling between

Jan 4, 1915

By V. K. Gupta

A detailed experimental study of the variations in grinding rate with particle size, particle load, ball diameter, ball load, mill diameter, and mill speed was carried out for a soft cement clinker and a hard cement clinker. The effects of the ball diameter, ball load and particle load were observed to be material (hardness) independent, and those of the particle size, mill diameter and mill speed to be material dependent. A sharp change in the grinding behavior was observed for both the clinkers at about 150 µm size. Below this critical size: (i) the hardness difference between the two clinkers became insignificant, (ii) variation in the grinding rate with particle size became markedly more pronounced, and (iii) mill speed had little or no effect on grinding rate. The importance of these results in the context of process optimization and control is discussed.

Jan 1, 1987

By E. R. Bauer

The trend in underground room-and-pillar coal mining is to employ remote-control continuous mining machines and extended cuts, 12 m (40 ft) deep or more. This system of coal extraction, adopted by over 435 mines, can create additional worker-safety hazards. To address the ground control and worker-positioning hazards, a combination of statistical analyses and numerical modeling was conducted. Initially, the reported roof-fall incidents and fatalities were reviewed to delineate the ground-control hazards. Then, the application of the Coal Mine Roof Rating (CMRR) for estimating safe extended-cut depths was evaluated. Finally, computer modeling to predict roof displacements during extended-cut mining was completed. The paper describes the results of these studies and their impact on the safety of extended-cut mining.

Jan 1, 1999