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By E. P. Jennings

The iron-ore deposits of Iron county, Utah, which rival those of Lake Superior in extent, are situated 275 miles south of Salt Lake City, and 25 miles south of Lund, a station on the San Pedro, Los Angeles & Salt Lake railroad. The range of hills containing the deposits has a general NE-SW. strike, and rise from a few hundred to 2,000 ft. above the Escalante desert, the ore being included in an area of 5 by 20 miles. The basal rock of these hills is diorite-porphyry. The flanks of the range are covered with limestone supposed to be of Carboniferous age, underlain in some localities by quartzite. Both formations are conformable to the porphyry, and are the remnants of beds that formerly covered the highest peaks, but have been removed subsequently by erosion. In the central and southern parts of the range, beds of Cretaceous sandstone rest unconformably on the eruptives. Rhyolite-flows occur to the south and southeast of the iron-ore deposits; and dikes and sheets of post-Tertiary lava are common. With the exception of a few springs, the range is destitute of water. Sage-brush, stunted cedars and the common desert-bushes constitute the only vegetation. Large beds of coal of poor quality occur in Cretaceous sandstones 15 miles east of the ore-deposits.

Jan 1, 1905

By Richard L. Stowe

Four NX-diameter holes were diamond-drilled in competent granite. Samples of the recovered core were used in laboratory tests. A borehole, plate-bearing device known as a Goodman jack was used to perform load deformation tests on the rock in the core hole. The majority of samples used in the laboratory tests were taken from depths in the hole at or within 5 ft of those at which the plate bearing tests were made. Borehole camera records, compressional and shear wave velocities, and densities were measured. Dynamic elastic constants were computed for the in-situ material, while comparative data (except camera records) were obtained in the laboratory. These data were examined to evaluate the significance of the in-situ modulus of deformation (Ed), the value computed from Goodman jack tests. Average test results show an excellent correlation between in-situ and laboratory data. The ratio of laboratory to field deformation modulus ranges from 9.82 to 7.21 for 3,000 and 9,000-psi stress levels, respectively. The dynamic modulus ratio, ED field/Ep lab, is 1.02; the compressional wave velocity ratio, V8 field/V8 lab, is 0.94; the shear wave velocity ratio, V, field/V, lab, is 1.12; and the density ratio, field [y/y] lab, is 0.95.

Jan 1, 1973

By E. I. Larsen, A. S. Doty, F. R. Hensel

The alloy under discussion is a Pig. I shows results of heat-treating tests nickel-silicon bronze and is one of many on two typical nickel-silicon bronze castings age-hardening or precipitation-hardening of the type on which the observations were copper-base alloys. The hardening constituent is a nickel-silicon compound.l The quenching temperature necessary to produce hardening by a subsequent aging treatment is a function of the composition and extends from about 700°C. to 950°C.; the aging temperature range extends from 4000 to 600°C. The work carried out by the authors of this paper was confined to cast alloys having compositions within the ranges of: 1.5 to 3.00 per cent Ni; 0.4 to 0.75 per cent Sj: balance. comer. made. A quenching temperature of 750°C. produces almost as high a hardness on subsequent aging as do quenching temperatures of 850' and 900°C. Several foundries have spent years of active and intelligent effort in trying to control the casting and heat-treating variables of nickel-silicon bronzes and finally gave up the attempts because of the inconsistencies of results.2 This undesirable characteristic was not manifest in the ultimate hardness or conductivity but primarily in tensile strength and ductility, as shown in Table I. The variation in tensile properties was often much greater than that existing on the alloys

Jan 1, 1941

By K. Matsuda, H. Tanaka, M. Mamiya, H. Majima

Copper cementation was studied from both thermodynamic and kinetic aspects. The temperature effect of copper cementation, which has been recognized as an anomalous result, and the rate enhancement phenomenon observed after the initial linear step are, in particular, focused in this work. The main results obtained are as follows; 1) Free energy changes of copper cementation reactions, calculated by the use of the "Correspondence Principle" of Criss and Cobble are rather insensitive to temperature. 2) A Flow-cell assembly consisting of a special cupric ion electrode, a calomel electrode and a potentiometer is particularly useful for the continuous measurements of copper cementation rate. 3) Two first-order reaction rate constants for the CU2+- Fe system were successfully determined by the use of the flow-cell assembly. 4) Activation energies determined for the initial rate and the 9 maximum rate of CU2+ - Fe system are both 4.6 kcal/mole. This fact suggests that the mechanisms of the initial reaction and the final reaction are essentially the same and both reactions are rate controlled by the diffusion in a boundary layer. The difference in the rate constants of them may fie explained by the effect of the nature of surface deposits. 5) Qualitative explanation of the rate enhancement phenomenon from the initial rate was successfully made by applying Bockris "Penetration Model."

Jan 1, 1976

By A. S. Doty, E. I. Larsen, F. R. Hensel

The alloy under discussion is a Pig. I shows results of heat-treating tests nickel-silicon bronze and is one of many on two typical nickel-silicon bronze castings age-hardening or precipitation-hardening of the type on which the observations were copper-base alloys. The hardening constituent is a nickel-silicon compound.l The quenching temperature necessary to produce hardening by a subsequent aging treatment is a function of the composition and extends from about 700°C. to 950°C.; the aging temperature range extends from 4000 to 600°C. The work carried out by the authors of this paper was confined to cast alloys having compositions within the ranges of: 1.5 to 3.00 per cent Ni; 0.4 to 0.75 per cent Sj: balance. comer. made. A quenching temperature of 750°C. produces almost as high a hardness on subsequent aging as do quenching temperatures of 850' and 900°C. Several foundries have spent years of active and intelligent effort in trying to control the casting and heat-treating variables of nickel-silicon bronzes and finally gave up the attempts because of the inconsistencies of results.2 This undesirable characteristic was not manifest in the ultimate hardness or conductivity but primarily in tensile strength and ductility, as shown in Table I. The variation in tensile properties was often much greater than that existing on the alloys

Jan 1, 1941

By F. L. Holderreed

A choosy in what they would smelt. The furnace charge had to be coarse, and it had to be rich. They discarded fines in excess of about 1/10 the total weight. They wanted 10% copper content and fussed about anything with as low as 5%. They concentrated the copper content of the charge as much as they could by prior selection. They roasted off enough sulfur to further enrich the copper content of the succeeding fall of matte (a melt of cuprous and ferrous sulfides or Cu2S.FeS). Then they desulfurized the iron and fluxed it by carefully adding silica (quartz, not silicates) for a slag of lower density than the cuprous sulfide (Cu2S or white metal). After skimming off the slag, they further desulfurized the white metal by blowing the molten bath with compressed air. The result was blister copper. Yesterday Their techniques and furnaces? Some experimented with mechanically rabbled roasters, but their standard roasting practice was burning coarse sulfide ore in 250-ton heaps. These heaps, approximately 24 x 24 x 6 ft, were burned for about 75 days down to 6-10% sulfur. The turnaround time for a given roasting position was 100 days. Assuming the base was a hearth, the calculated rate of treatment was on the order of 0.004 tpd per sq ft.

Jan 1, 1971

By Franklin R. Carpenter

Pyritic smelting, so-called, as practiced in the Black Hills is pyritic smelting only in the sense that Dr. John Percy uses the expression in his " Metallurgy of Silver," where he describes a process for smelting dry silver-ores in connection with iron pyrites, to form a regulus. The ores treated by this process in the Black Hills are very siliceous, averaging about 74 per cent. of silica, from 10 to 20 of iron oxide, 4 or 5 of alumina, and from 2 to 4 of lime. In 1889, while Dean of the South Dakota School of Mines, I took up the question of their smelting. There were neither copper- nor lead-ores in the Hills; hence pyrite and pyrrhotite, of which there are large deposits, were employed to form a regulus. This mixture of pyrite and pyrrhotite, besides being absolutely barren of gold and silver, carried an average of 30 per cent. of silica. The only basic material available as a flux for the great excess of silica in the ores and in the pyrite was a dolomitic limestone. Moreover, the local coke gave 24 per cent. of ash, 60 per cent. of which was silica—as unpromising a set of conditions as can well be imagined. We had before us the examples of Mr. W. Lawrence Austin, of this Institute, who had experimented at Toston, Montana,"

Jan 1, 1901

By S. L. Couling, G. W. Pearsall

MOTT and Hainesl have summarized the available techniques for the examination of aluminum and some anisotropic metals under polarized light. Many of these techniques are rather complicated and cumbersome. This note presents a simplified procedure for using polarized light to obtain information about the crystallographic orientation of any particular grain in a magnesium alloy. Since other hexagonal metals are more anisotropic than magnesium, similar methods might well be applied to them. Ernst and Laves2 produced a double-refracting layer on magnesium alloy specimens by SuCCeSSiVe etches in solutions of perchloric acid in alcohol, magnesium perchlorate in perchloric acid and alcohol, and calcium and magnesium carbonates in water. They examined their specimens under polarized light and were able to determine the direction of the hexagonal axis in any particular grain from a measurement of the extinction behavior of that grain. The disadvantages of their technique were the complexity of the etching procedure and the explosive hazard of the perchloric acid-alcohol solutions. Results equivalent to those of Ernst and Laves were obtained in this investigation after etching specimens for 6 to 8 sec in an acetic picral solution containing 100 parts 6 pct picral, 10 parts distilled water and. 5 parts acetic acid. A. similar etch has been used by George3 in earlier metallographic

Jan 1, 1958

By P. Nelson, K. L. Gunsallus, A. R. Ingraffea, J. F. Beech

INTRODUCTION Fracture toughness, KIC, is an intrinsic material property and is a measure of the energy required to create new surface area in a material. Fracture toughness measurements can be made for a wide range of rock types (Ouchterlony, 1980). As a measure of energy of comminution, fracture toughness might be used for more sensitive predictions of Tunnel Boring Machine (TRM) performance than are possible with other index measures in current use. This paper describes part of an ongoing, comprehensive, analytical/experimental program aimed at evaluation of KIC in such a role. The program includes efforts to: 1. Provide a firm analytical basis for a test specimen geometry: the core-derived short-rod. 2. Develop simple, inexpensive testing equipment and techniques. 3. Evaluate the accuracy of the above by testing rock and other materials and comparing the measured fracture toughness with those obtained by other methods. 4. Measure fracture toughness of a substantial number of different rocks from three ongoing TBM projects. 5. Compare fracture toughness results with other strength measures. 6. Compare all test results with observed TBM performance in the three projects. Presented here are summaries of all but the last of these efforts. Comparative evaluation of KIC as a more senstive rock property for TBM performance prediction will be the subject of the oral presentation and a subsequent paper.

Jan 1, 1982

By Jackson R. Pellett

INTRODUCTION The Friedensville mine is situated in Upper Saucon Township, Le- high County, Pennsylvania, in the southern central part of the Allentown quadrangle of the United States Geological Survey, approximately 5 miles southeast of the City of Allentown and 4 miles south of the City of Bethlehem. Zinc was first discovered in the Friedensville area early in the 19th century and several mines were operating during the latter part of the century. Zinc oxide was produced in 1853 and zinc metal in 1859. All mining in the area ceased in 1893 chiefly because of an unfavorable economic situation caused by a severe ground water problem and competition from the higher grade ores in New Jersey. Property acquisition by the New Jersey Zinc Company began in 1899 and periodic exploratory drilling was carried on until 1940 when sufficient reserves were proved for development of a mine. Shaft sinking was undertaken in 1947 and, due to severe hydrologic conditions, was not completed until 1952. Production began in 1958 and today the mine is producing about 64,000 tons of zinc concentrate per annum. The concentrates are trucked to the Company's smelter at Palmerton, Pennsylvania, approximately 30 miles north of Friedensville. The mine also produces from its mill tailings industrial and agricultural grades of limestone for commercial markets.

Jan 1, 1970

By J. L. Gillson

Historically, rock deposits and sand deposits of titanium minerals came into production about the same time, although there may be some argument as to what is meant by production. Beach de- posits of heavy minerals in India (Figs. 1-4) and Brazil (Figs. 5) were worked for monazite about the turn of century, but as there was then no market for titanium minerals, these were thrown away. The rock rutile deposits at Roseland, Va., Fig. 6, were worked to supply rutile for titanium chemicals and for coloring ceramics long before there was a titanium pigment business. The pigment industry started about the middle twenties, both in Europe and the U. S., and almost simultaneously the rock deposits at Ponte Vedra Beach near Jacksonville, Fla., were worked for titanium content. Since those days, production from both types of deposits has continued to grow at a rapid rate; many deposits of both types have been found, and reserves have grown to very large figures. In total tonnage of reserves, there is no doubt that the rock deposits are far ahead of the sand deposits; nevertheless there is a very large tonnage of commercial sands available. It is the quality of titanium mineral in the sand and the relatively lower costs of operating sand deposits that have kept them abreast, at least in annual tonnage produced, with the rock deposits.

Jan 4, 1959

By E. T. Turkdogan, L. S. Darken, R. G. Olsson, H. A. Wriedt

Several aspects of the calcination of Michigan limestone were investigated: the rate of calcination of limestone spheres with diameters from 1.8 to 14 cm at temperatures from 800° to 1200°C by a thermogravimetric method; the temperature profile across limestone during calcination; the excess pressure developed in the interior of the stone during calcination; the pore surface area, pore volume, and effective gas diffusivity in burnt lime; and the microstructure of polished and fracture surfaces. It is found that, over a wide range of experimental conditions, the difference between the surface and center temperatures remains essentially unchanged during the latter half of calcination. From the rate of weight loss after about 50% calcination, the value 0.00126 cal per cm sec degree is found for the effective thermal conductivity of burnt lime. From the excess internal pressure measurements, i.e., 0.4 to 6 cm Hg at 800° to 1200°C, the permeability of burnt lime is estimated to be within the range 8 X 10-' to 5 X 10' sq cm. With increasing temperature and time of calcination, the pore structure of burnt lime coarsens as indicated by a decrease in the pore surface area, pore volume, and an increase in the average pore size. For the temperature range 600° to 835°C the ratio (effective gas diffusivity/molecular diffusivity) is about 0.18.

Jan 1, 1974

By Edward J. Way

+1KLEINFONTEIN GROUP CENTRAL ADMlNISTRATION, BENONI, TRANSVAAL, S. AFRICA. The cost and the speed of sinking a shaft are factors of so great importance in operating a mine, that the data given in Table I., herewith published, will be of interest and value to all engaged in practical mining; and for this reason the data are communicated for permanent and accessible record in our Transactions. The figures 'of cost cover the period from January 1, 1903, to May 31, 1903, during which time the total depth sunk was 858 ft. So far as I know, the cost of sinking per foot (£13,15s., 11.04d.) of a shaft of the dimensions 21 ft. by 6 ft. in hard rock, is the cheapest yet on record; and the speed of 213.5 ft. per month, which was attained during May, 1903, is also the best record for speed in sinking in rock so hard as that of this shaft. During the period from January 1 to May 31, 1903, there were 144 rounds worked, involving 4,032 holes, of a total depth of 28,963 ft. 2.4 in., which is equivalent to an average depth of 7 ft. 2.2 in. per hole bored. These data are of added interest from the fact that the work was done practically by native labor.

Jan 1, 1905

A joint statistical report released by the U.S. Department of Commerce and U.S. Securities and Exchange Commission indicates that business investment in new plants and equipment is expected to total $81.8 billion during 1971. This figure is based on the findings of a survey conducted in late April and May and reflects about a 1 ½ % decrease in investments from the $83.1 billion projected in February. Mining, on the other hand, is still in a bullish mood and is expected to spend $1.99 billion in 1971 compared to $1.89 billion in 1970 and $1.86 billion in 1969. Based on figures quoted above, mining investment in 1971 should show a 5.2% increase over 1970. Carl E. Bagge, president of the National Coal Association, was the dedicatory speaker at the new Milton R. Young Station of the Minnkota Power Cooperative in North Dakota. This new power plant incorporates many innovations which have overcome the problems of using the low-cost lignite abundant in the area. According to Bagge, this development and President Nixon's recent request for an extra $10 million for coal gasification plants is helping the region lead the way in providing for the power needs of the future. He also maintains that gasification of coal can reconcile coal consumption with the demand for cleaner air, and also assure the nation of adequate pipeline gas.

Jan 1, 1971

By A. F. Banks

INTRODUCTION Selective flocculation as a method of desliming potash flotation plant feed has been in commercial use since November, 1974.l It was installed to replace a 1ess efficient mechanical desliming process. While most plants operating in the Saskatoon area of Saskatchewan were designed for 4% to 5% insolubles in practise the quantity and quality of the insoluble materials in the ore has been variable. The variability of the ore has contributed to less than optimum efficiency in the desliming and consequently, the potash flotation circuits. This lower than expected efficiency contributed to the commercialization of a patented process2 through large scale pilot plant testing. Referring to published information and experience, the application of selective flocculation-flotation of slimes to sylvinite ores will be compared with the more conventional mechanical methods of desliming. THE ORE The ore beds being mined in the Saskatoon area of Saskatchewan have proven to be much less uniform than originally thought (Figure 1). The insoluble content of the plant feed is variable in both quantity and quality due to two factors, the presence of disturbances and the structural weakness of the mud seams immediately above the ore beds. Some alteration of the insolubles in the vicinity of disturbances has made them more difficult to liberate and makes ore from the disturbed areas less amenable to treatment.

Jan 1, 1980

By J. E. Metcalfe

Proceedings of the Fourth Empire Mining and Metallurgical Congress, Great Britain 1949. Part II published at the Offices of the Congress in London, England, 1139 pp. The price of these proceedings is £ 2. The parts may be purchased separately at a cost of £ 1 each.-Part I of this book covers a report of the organizing committee, the inaugural meeting and presidential address, banquet at Guildhall, welcome by Sir Richard Livingstone at Oxford. and final session. Technical session and papers are also covered in Part I. Part II covers such topics as coal, present-day trends in mineral dressing and metallurgy. Mining Engineer's Survey Manual. By J. E. Metcalfe. Published for "Mine & Quarry Engineering" by Electrical Press, London, 1951. 341 pp., illus., charts, diagrs., tables, 8 ¾ x 5 1/ in., cloth, 30s., available from Percival Marshall & Co., Ltd., London, and British Book Centre, 122 East 55th St., New York 22, N. Y. Beginning with a brief treatment of surveying fundamentals and a discussion of the correlation of surface and underground surveys, this practical manual continues with descriptions of surveying practice both above and below ground including stopes, inclined shafts; etc. Space is devoted to sampling and valuation, geological considerations, and descriptions of modern surveying instruments. The organization of survey operations is covered in the last chapter.

Jan 1, 1952

By Esteban Domic, Eugene O. Brimm

The Lo Aguirre ore deposit of Sociedad Minera Pudahuel is expected to have a life of 12 years, producing 16,500 mt per year of copper cathodes. The total copper content of the ore ranges from 2% in acid-soluble form to 2% as sulfides. Sociedad Minera Pudahuel chose TL leaching, solvent extraction, and electrowinning as the processing steps to give low investment and operating costs. Design and operating criteria of the TL leach plant have been obtained in an experimental program carried out since 1974. Bench scale tests indicated that 90% of the oxidic copper and 35% of the sulfidic copper could be extracted to give 5 gpl copper by treating crushed ore with acid, curing, and rinsing in a column with a dilute acid solution containing ferric sulfate which is requllred to solubilize the sulfides. These results were verified in a pilot plant which combined leaching, solvent extraction, and electrowinning. Raffinate was recycled to the leaching circuit after oxidation to regenerate ferric ion. Refinements in the processing have resulted in significant improvements in extraction to give 95% to 98% recovery of the oxidic copper and 55% and 60% of the sulfidic copper. The plant is expected to give this degree of recovery. As a consequence, the original plan to include a concentrator in the plant has been abandoned.

Jan 1, 1980

By C. J. Wilhem, J. M. Devine

A corrosion-testing apparatus which operates in the field and which will determine the comparative resistance of various ferrous materials to corrosion by gaseous hydrogen sulfide at ordinary temperatures is described. The principle of the uniform method of testing is to allow natural gas containing hydrogen sulfide, direct from its source in the field, to flow over the group of specimens for a given period of time, and subsequently to estimate the corrosion sustained by each specimen by determining its loss in weight. The comparative results obtained when specimens of 47 representative ferrous materials of described typical composition \\ere tested at ordinary temperatures with natural gas containing hydrogen sulfide are given in tables showing average penetration of metal, Inches per year. The primary purpose of the work Mas to determine the possible utllity to the petroleum and natural gas industries of ferrous materials that are commercially available, and no attempt is made to discuss the results of the tests from the metallurgical standpoint. The following is a summary of the results obtained: 1. Steels containing 12 to 27 per cent of chromium showed the highest resistance to corrosion. The presence of nickel In these high-chromium steels did not affect their resistance. 2. Steels containing approximately 5 per cent of chromium showed comparatively high resistance, but somewhat less than that of the high-chromium steels.

Jan 1, 1934

By Linn M. Farish

The reported production of petroleum in the Dominion of Canada for 1930 was 1,555,199 bbl., an increase of 455,373 bbl. over 1929. Alberta accounted for nearly all the production with Ontario and New Brunswick, the other two productive provinces, contributing less than 1 per cent, of the total. The completion of about 25 producing wells in Alberta was more than sufficient to offset the decline of the older wells in that province and the small decline in Ontario. The production of about 5000 bbl. in New Brunswick represents a restricted output to meet the market demand. Table 1 shows the production by provinces for the past 10 years. The consumption of natural gas for all purposes in Canada reached a new record of practically 40,000,000,000 cu. ft. in 1930, which was a considerable increase over 1929. The estimated value of the gas output was $10,500,000, against a little over $5,000,000 for the total petroleum production. Gas wells in Alberta accounted for over 75 per cent. of the total, with Ontario second and New Brunswick a poor third. The outlook for 1931 is for very little change in production of either gas or oil in Ontario and New Brunswick but for a substantial increase in both in Alberta.

Jan 1, 1931

By Keith E. Robinson, Brian Stimpson

INTRODUCTION In inclined sedimentary strata slope failure may occur by sliding along bedding and along a discontinuity or weak zone, as illustrated in Fig. 1. This mode of failure may be called 'bi-linear', as the failure surface is comprised of two linear or approximately linear segments. This type of failure has been suggested for the famous Frank Slide, Alberta, Canada (Cruder and Krahn, 1973) in which an estimated 90 M 5 tons (8.97 x 10 MN) of rock separated from Turtle Mountain and buried the town of Frank. Also, with the increasing depth of open pits and the construction of highways through inclined sedimentary strata this mode of failure is of major concern to the rock slope stability engineer. A computer program for calculating factors of safety for this slope failure mode is provided and includes the ability to vary shear strengths of potential slide surfaces, ground water elevations and wedge geometry. LIMITING EQUILIBRIUM MODEL The simple limiting equilibrium model used in the analysis is shown in Fig. 2. It is assumed that jointing is orthogonal to bed- ding and that the interface between the upper and lower wedges there- fore corresponds to a joint plane or planes. No shear strength is attributed to the interface so that the resultant force, P, from the upper wedge acts normally across the interface. The normal loads

Jan 1, 1983