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By D. R. Piteau, A. MacG. Robertson

Strength, permeability, and deformational properties of a rock mass are influenced and often controlled by the geological discontinuities within the mass. These properties are often determined by physical tests conducted within and on portions of the rock mass under consideration. Any extrapolation of these test results to other portions of the rock mass assumes that a similar pattern of discontinuities, having similar properties, exists throughout the region of extrapolaion. A survey in which various joint properties of interest are measured may be conducted to sample the joint population of the mass. Suitable data manipulation and handling techniques are developed to permit the definition of the joint population of the rock mass. The validity of the extrapolation of test results may then be assessed.

Jan 1, 1974

By J. S. Wakeman

The techniques of testing the physical properties of green pellets produced in a batch balling test are described. It has been found that these physical properties, i.e. drop resistance, wet compressive strength, and plastic deformation under load, are generally related to the moisture content of the wet balls. A "criterion" method of analyzing data from a series of batch tests is discussed. This method facilitates the comparison of results of various test series. A time-sharing computer program, which correlates the test data from a batch series, generates the "criterion" values for subsequent comparison and analysis, and produces X, Y plots of the various moisture-strength relationships, is presented. Examples of computer output and use of the "criterion" evaluation method are given.

Jan 1, 1973

By Walter L. Crow

MUCH has been published on highly technical phases of grinding. Very little has been written on how a mill man can improve his operations by determining the optimum size assortment of grinding balls that should be added as a makeup charge. This ball rationing is not to be confused with the ball ration used as an initial charge when the mill is started up. Ball rationing is considered for one or more of the following purposes: 1) to increase throughput of the mill, 2) to reduce the power required per ton of ore ground to the desired size, 3) to reduce steel consumption per ton of ore ground, 4) to improve product size, and 5) to lower retention time of ore in the mill.

Jan 7, 1957

By William C. Peters

The experiences of exploration crews with mineral land acquisition could be graphed to show a correlation with the natural law that everything tends to become more so. A single step, such as that of taking a series of deep soil samples, is sometimes delayed until some sense can be made from floating unpatented claims which are obscure in orientation as well as position-placer claims, overlapping lode claims, location posts with empty Prince Albert cans and claims with no apparent assessment work for ten years. Add to this some patented claims without monuments, a state or federal withdrawal area which may or may not invalidate preexisting claims, a loosely defined tunnel site, and some ranchers who understandably resent the separation of surface rights from mineral rights.

Jan 1, 1970

By William B. Phillips

It would be hard to find a mineral region that has been more beset with " processes" for the extraction of gold from auriferous sulphides than North Carolina. And it would be hard to find a mineral region less sought by capital. So many promising mines have come to grief here (perhaps because they were too "promising"), SO many "processes" have been tried and abandoned, so much expensive machinery has been bought and thrown aside, that to invite money here for investing in gold mines is almost sure to cause a smile of incredulity, or a sigh of disappointed hopes. Within the writer's personal knowledge, at least five disastrous failures have followed the introduction of as many processes. It would seem as

Jan 1, 1889

By G. Carman Ridland

Front Range, Colorado: The majority of the rocks comprising the Front Range of Colorado are pre- Cambrian schists, gneisses, and intrusives which have been elevated to form part of the Southern Rocky Mountain physiographic province. The region is noted mainly for its production of gold and silver, but ores of tungsten, fluorspar, uranium, copper, and iron have been worked. Geological literature describes pitchblende and other radioactive minerals occurring at Jamestown, Boulder County; Central City, Gilpin County; and Lawson, Clear Creek County (fig. 1). These three adjoining counties cover most of the highly mineralized section of the Front Range which extends from James- town to Breckenridge. As far as the writer is aware, uranium has been found only in the portion north-east of Lawson.

Jan 1, 1950

By S. C. Termes, P. E. Richardson, R. L. Wilfong

This paper discusses recent Federal Bureau of Mines research on the selective flocculation of various minerals with insoluble cross-linked starch xanthate (ISX). ISX is insoluble, has a shelf life of more than a year when kept cold, and has a higher molecular weight due to cross-linking than the soluble, non-cross-linked starch xanthate used in previous flocculation studies on nonsulfide minerals. ISX readily flocculates a number of sulfide mineral fines, but no silicious gangue. Floc formation, floc size, and settling rate are dependent on pH. The pH dependence, however, differs for each mineral. Bornite has been selectively flocculated from bornite-quartz mixtures, and the bornite-containing flocs were separated from the unflocculated quartz using decantation and washing procedures.

Jan 1, 1984

By C. L. Dake

RESIDUAL deposits occur both as products of weathering and as products of hydrothermal decay. PRODUCTS OF WEATHERING That climatic conditions affect greatly both the rate and the results of weathering, is shown. in temperate, polar, arid, and tropical regions, each of which will be considered separately. Weathering under Temperate Climates The decomposition of any rock is accomplished by the removal of the more soluble bases, and a concentration of the relatively insoluble oxides of iron, aluminum, and silicon. By reason of its some-what greater solubility, silica is much more subject to removal than iron and alumina. The two important residual end products of weathering are sands and clays, the former consisting essentially of quartz, and the latter of kaolin and limonite.1

Jan 5, 1915

By W. E. C. Eustis

During the last year I had occasion, on behalf of our New York copper works, to send to various chemists samples, intended to he accurate, of material which we were buying and selling, and I was astonished to find what differences were reported. After talking over the probable reasons for this with a number of chemists and metallurgists, it was suggested that it would be of real use and some scientific interest to send samples to the different chemists, and take such care in making up the samples that we could feel sure that each chemist had as nearly identical a sample as it was possible to make. After some consideration it was determined to send a mixture which should carry about 50 per cent. copper, and

Jan 1, 1883

By K. E. Niermeyer, J. A. Bratt, B. A. Fahm, B. A. Kennedy

The instrumentation, monitoring, and prediction of a major slope failure at the Chuquicamata mine are described. In December 1967, preexisting tension cracks on the south end of the east wall of the mine began to open. Various forms of instru¬mentation were installed for continuous monitoring. These systems included tension crack stakes, crack extensometers, linear extensometers, tape and transit lines, sliding wire contacts, and a seismograph. From the information obtained, the failure date was accurately predicted some five weeks before failure, enabling the mine to reroute truck and rail access; hence, causing a minimal mine shutdown of 21/2 days and preventing any injuries to person or damage to equipment. The shape and form of the sliding mass are analyzed, as are possible modes of failure.

Jan 1, 1972

By Frederic Benard

RECOVERY of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.1 During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature.

Jan 1, 1938

By E. L. Kapfer

A preliminary description is made of the field of automation and optimization of the oxygen blast furnace process. The concept of static and dynamic process control is illustrated. After a short general description of all factors concerning the optimization of this process, a learning system is derived which gives better results than models previously used. This learning or self-adaptive control system uses statistical methods with exponential aging of process data and requires derivation of multi-variable functions of the process for which measurements can be made available. The practical application of this new procedure and of additional measuring instruments are discussed, and results obtained in plants using the adaptive control system are described. A survey of European steel plant automation using the Siemens technique is presented.

Jan 1, 1969

By George C. Toland, Ronald E. Versaw

Most existing impoundment ponds and dams leak effluent into the soil or rock upon which they are constructed. However, proposed environmental legislation will require very stringent control of the release of toxic effluents such as cyanide. More exacting investigation, design, and construction techniques than have been used in the past will be required to satisfy these new regulations. The types of field and laboratory investigations required to develop the data for the design of an impoundment system containing toxic effluent are discussed, together with the technical considerations necessary to design this system. Design topics include reservoir sealing with natural and man-made materials; embankment sealing; embankment design considering stability, surface hydrology, capacity, and downstream catchment basins; and special implications of cyanide effluents.

Jan 1, 1977

By Kenneth Robertson

THEREi9 probably less known of this subject than of any other connected with the metallurgy of iron. In all the books that treat of this mattes, there are given analyses of slags, their chemical formulae, the loss of iron, etc. ; but few, if any, give the character of the iron made at the time ; none give analyses and physical characteristics of the ores and limestones used, and they present merely isolated examples from various furnaces, and consequently one is more frequently puzzled than enlightened after reading them. During two years I have had occasion to analyze the slags and many of the pig-irons from two furnaces, and for this article I have made analyses of all the different grades of pig made by them. A

By Owen S. Roberts

During the design phases of a conveyor system, the question arises regarding the type of drive required for each application. The paper shows that the correct drive for any particular application is the one that satisfies the criteria established for that application in the most economical manner consistent with such considerations as site location, availability of spare parts, area environmental conditions, power supplies available, etc. Following discussions of various mechanical arrangements for the drives, motor types and their characteristics are considered along with the control means of modifying these characteristics to satisfy individual requirements. These characteristics are all illustrated graphically. After selecting the motor and its starter, control accessories and interlocking arrangements as applied to material handling systems are discussed.

Jan 1, 1973

By D. F. Strong

Most Newfoundland mineral deposits can be clearly classified as within rocks formed either as accreting plate margins (ophiolitic pyrite-chalcopyrite massive sulfides such as Betts Cove, Whalesback, York Harbour, chromite at Lewis Hills, and asbestos at Baie Verte), at consuming plate margins (Kuroko-type polymetallic massive sulfides such as Buchans and Pilleys Island, porphyry-type Mo-Cu at Rencontre, fluorite at St. Lawrence), or within plates (zinc deposits at Daniels Harbour, sedimentary iron ores at Wabana, manganese in Conception Bay.) As these metallogenic patterns can be convincingly extrapolated southward into the Appalachians and northward to the Caledonides, they provide an important means of eliminating and selecting areas for particular exploration targets. Some criteria are described for the recognition of these environments of differing economic potential.

Jan 1, 1975

By Kenneth Robertson

THERE is probably less known of this subject than of any other connected with the metallurgy of iron. In all the books that treat of this matter, there ore given analyses of slags, their chemical formulae, the loss of iron, etc. ; but few, if any, give the character of the iron mode at the time; none give analyses and physical characteristics of the ores and limestones used, and they present merely isolated examples from various furnaces, and consequently one is more frequently puzzled than enlightened after reading them. During two years I have had occasion to analyze the slags and many of the pig-irons from two furnaces, and for this article I hove made analyses of all the different grades of pig mode by them. A

Jan 1, 1873

By R. S. Archibald

THE Blueberry mine is about 10 miles west of Ishpeming, Marquette County, Michigan. The property consists of about 2000 acres in sets. 3, 4 and 5, T. 47, N.R. 28W. and sets. 32, 33 and 34, T. 48, N.R. 28W., and, excepting one intervening 80-acre tract, contains the iron formation for a length of about 2 1/4 miles. The property is traversed by State Highway M-28 and is served by three railways, the Chicago & Northwestern, the Duluth, South Shore & Atlantic, and the Lake Superior & Ishpeming. The Northwestern transports the ore to a dock at Escanaba; the other railways, to Mar¬quette. Ore for Chicago goes via Escanaba and that for Lower Lake ports, as Detroit, Cleveland, and Buffalo, via Marquette.

Jan 1, 1935

By Theodore H. Eyde

The Superior Oil Co. drilled two holes, 4720 and 5940 ft, respectively, using conventional oilfield rotary drilling equipment. The results indicated that large rotary drills can be adapted to mineral exploration purposes with few modifications. The principal advantages are: a large hole diameter, excellent samples of cuttings, a geolograph which is a constant drilling record, rapid penetration even in hard rocks, and the ability to use electric logs for measuring the properties of the rock being penetrated. The disadvantages are the high cost of mobilization, drilling, and oilfield service at remote locations. Though the oilfield sampling techniques are adequate for identifying lithology, improvements are necessary to obtain representative samples for analytical purposes. As deeper targets are explored, mineral exploration organizations will have to resort to rotary drilling.

Jan 1, 1975

By J. O. Lewis

Oil wells usually reach their maximum daily output shortly after they are completed. From that time they decline in-production, the rapidity of decline depending on the output of the wells and on other' factors governing their productivity. The production curve of a well shows the mount of oil produced per unit of time for several consecutive periods; if the conditions affecting the rate of production are not changed by outside influences, the curve will be fairly regular, and, if projected, mill furnish useful knowledge as to the future production of the well. By the aid of this knowledge the value of a property may he judged, and proper depletion and depreciation charges may be made on the books of the

Jan 2, 1918