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By R. T. Saxon

Prior to November 1975 there were several failures of front -wheel spindles on large haulage truck s in B.C., attributed to fatigue cracks. Since that time, a non-destructive test program has succeeded in detecting the cracks before catastrophic failure, However, the author regards the failures as just one example of a. general unreliability in large high-strength steel castings and urges the industry to look to forgings for sensitive components of heavy equipment.

Jan 1, 1977

By Rob Jameson

"Although seismic retrofit is recognized as a key micropile application, widely-used reference documents do not clearly address design and testing recommendations for micropiles that are loaded primarily under seismic conditions. The principles of micropile design and construction and their application to seismic retrofit projects are well understood and executed by leaders in the field. As the micropiling market grows, a wider audience relies on the information presented by DFI and similar industry groups. State-of-practice updates appear periodically in conference proceedings, but examination of recent bid documents makes it clear that there are opportunities to improve the specification of load, deflection, testing and acceptance criteria on many seismic retrofit projects. Updates to the FHWA Manual or DFI Sample Specification that specifically address seismic retrofit cases would be useful tools to disseminate information and enhance the state of practice.Micropile Survey UnderwayAs one step in this process, I am distributing surveys to contractors and designers prior to DFI Super Pile ’09 (June 4-6, San Francisco) seeking recommendations for design and testing procedures applicable to seismically loaded micropiles. I am also requesting any existing references that could be promoted as a standard for these cases. Anyone interested in participating in this survey, should contact me at rjameson@malcolmdrilling.com. Seismic RetrofittingMicropiles are ideally suited to seismic retrofit applications. Their high-tensile and compressive capacity can sustain the large concentrated loads induced during seismic events. They can be installed within and around the access limitations of existing structures, and can be drilled through and grouted into the wide variety of soil and rock materials encountered in seismically active zones.Seismic retrofits have included micropiles since the early 1990s, and they are now widely specified in the Western U.S. In the San Francisco Bay Area alone, thousands of micropiles have been installed for seismic upgrades of highway and transit aerial structures, and retrofits of commercial, residential and public buildings. Micropile use is growing in both public and private sectors, with large-scale retrofit projects currently underway for both the Bay Area Rapid Transit (BART) system-wide upgrades and renovations at San Francisco Airport."

Jan 1, 2009

By G. Mellgren, O. Mellgren

The conductivity of a solution is often used industrially to control the salt concentrations of reacting systems, normally using electrodes made of glass fitted with platinised platinum electrodes. When a standard platinum conductivity electrode was used to control the acid fed to the leaching circuit for an ilmenite flotation concentrate at Titania, Norway, a deposit of calcium sulphate (containing some calcium phosphate) covered both the platinum electrode and the external glass fitting, rendering the electrode inefficient in the course of a few minutes. A new electrode consisting of a casing, two measuring tubes and an electrode stem is described and illustrated. A significant advantage of its design is that the useful range of conductivity measurement can be adjusted by adjusting the concentration of the electrolyte in the electrode. It has been in use at Titania for about four years with an electrolyte consisting of 0-1 n HCI. It is robust and demands little maintenance.

Dec 1, 1971

THE John Fritz Medal Board of Award, at its regu¬lar annual meeting Oct. 19, awarded its gold medal to Herbert Clark Hoover. Thus ended a process of selection begun a few years ago. The award was tentatively made a year ago by the Board, which is composed of sixteen recent past-presidents of the four national societies of Civil, Mining and Metallurgical, Mechanical, and Electrical Engineers, having together a membership of nearly 60,000. The sixteen members of the Board are: American Society of Civil Engineers : C. E. Grunsky, Robert Ridgway, George S. Davison and John F. Stevens ; American Institute of Mining and Metallurgical Engineers: William Kelly, J. V. W. Reynders, Samuel A. Taylor and E. DeGolyer; American Society of Mechanical Engineers: Fred R. Low, D. S. Jacobus, Dexter S. Kimball and Charles M. Schwab; American Institute of Electrical Engineers: Farley Osgood, M. I. Pupin, C. C. Chesney and Bancroft Gherardi.

Jan 1, 1928

By P. Beauvais

Philip Beauvais, from the Met Office's International Mining and Agriculture Department, explains the need to understand the impact of the weather and climate when developing future mine sites.

Mar 1, 2015

By John W. Graham

To start my talk, I thought it might be helpful for us to define the term "aggregate", so I went to the dictionary. Webster has several listings under "aggregate", and I found the following: "1. A mass or body of units or parts somewhat loosely associated with one another." Well, I didn't like that term "loosely" so I read on. "2. Crystals of one or more kinds of mineral or rock fragments." That sounded better, but I still read on. "3. Any of several hard inert materials used for mixing with a cementing material to form concrete or mortar." That sounded even better, but it should be a little broader. So I would like to define "aggregates" for you as follows: "Hard, inert fragments of rock or minerals used alone or with cementing agents to form products essential to nearly all types of construction." Usually aggregates are sand, gravel, or crushed stone, but other minerals such as clay or shale can be heated and become aggregates. What are some of the construction uses? Well, we've already mentioned concrete, as used in streets and highways, sidewalks and parking lots, airports and all kinds of building construction, not to mention bridges and swimming pools, and docks and breakwaters, just to list some of the uses. Our way of life couldn't exist without concrete. And you can't have concrete without aggregates,

Jan 1, 1977

By S. Yuan

A large-scale work scheduling algorithm has been developed in the Mine Management Support System (MMSS) for assigning workers to prioritized jobs on a shift basis. This study basically concerned the formulation of a reliable mathematical programming model to handle the problem, the achievement of an efficient solution of the model, and the implementation of the algorithm to the worker assignment problems of a large underground coal mine. The results showed that the work scheduling algorithm can make optimal assignments efficiently. It is believed it has potential significance in improving manpower utilization and can offer great help to coal mine managers in making efficient manpower allocations.

Jan 1, 1994

By Anderson, Burton E.

FOR several centuries diamond mining has been an adventurous, profitable and enticing industry in Brazil. Some of the world's most valuable diamonds have been found in this country. Two of the most famous stones are the "Estrella do Sul" (Southern Star), weighing 2541/ karats, and the "Branganca," weighing 1680 karats in the rough and 367 karats cut. For a great number of years the stones extracted and sold were mostly the white diamonds used for jewelry. Within the last thirty years black diamonds have been developed as an abrasive cutting material and in these black diamonds the State of Bahia, Brazil, has a monopoly of the world supply. Carbons, as they are commonly called, are being used for core-drilling, polishing, cutting, wire-drawing, and vari-ous other applications in which such a hard substance is required. Bernard Bandler & Sons, of New York City, have selected, graded and delivered these carbons to the United States markets.

Jan 1, 1932

By Louis Moyd

In the preparation of illustrations to accompany reports of investigations concerning particle shapes of various natural and manufactured materials proposed for use as fine aggretates in concrete structures, it was found that stereoscopic views of such materials presented the information much more effectively than the usual two-dimensional photographs. With the whole-hearted cooperation of the Photographic Section, a technique was developed in the petrographic laboratory of the Concrete Research Division, U.S. Corps of Engineers, at Clinton, Miss., for simple and rapid preparation of paired stereoscopic photographs and micrographs. The method requires only equipment which is usually part of the general stock of any laboratory, and it is adaptable for all purposes in which three-dimensional views would be found superior to ordinary photographs.

Jan 1, 1949

By Juptner von Jonstorff

A discussion of the paper by Messrs. Jüptner von Jonstorff, Blair, Dillner and Stead, read by title at the Lake Superior meeting, but presented first at the New York meeting of the Iron and Steel Institute (October, 1904), and here published under a mutual agreement between the two Institutes. Correspondence. MR. R. HAMILTON (Glengarnock) wrote to say that it was known for many years, that unless certain precautions were taken in dissolving the sample, there was a liability to obtain a solution from which the ammonium-molybdate solution would not precipitate the whole of the phosphorus. In 1877 Blair and Finkiner independently attributed this interference to the presence of carbonaceous matter in the solution, derived from the action of acids on the combined carbon of the metal, and they directed that the solution should be prepared in such a manner as to destroy these carbonaceous compounds. This was practically effected by evaporating the acid solution to dryness and roasting the residue. Adolf Tamm, in 1884, accentuated the same view. There are methods founded on the above-mentioned observations which leave nothing to be desired in point of accuracy, but the evaporation to dryness with subsequent roasting and re-solution consumes much time, besides the minor inconvenience caused by large amounts of acid fumes. In 1888 P. W. Shinier suggested that the incomplete precipitation of phosphorus was due to incomplete oxidation of -.the phosphorus, and proposed to render all the phosphorus precipitable by oxidizing the solution with potassium permanganate, etc. Experiments were made to test the accuracy of this view (details will be found in the Journal of the Society of Chemical Industry, vol. x., p. 904), and the results obtained seem to-prove that it is the correct one. It was first proved that carbonaceous matter in solution did not prevent the precipitation of properly oxidized phosphorus

Mar 1, 1905

By Robert B. Sosman

ONE of the most neglected fields for physicochemical education as well as for research is that of high-temperature phenomena. Few universities or technical schools give instruction in the physical chemistry of substances at high temperatures. On the contrary such instruction is almost entirely confined to the region between the freezing and boiling points of water. This field should be extended to a much wider range of temperatures, both low and high. Such an extension is logical, sound, feasible, and practical.

Jan 1, 1943

By D. Hnrrington

THE Dust Symposium was attended by approximately 100 persons, nearly all of whom remained from the starting hour (2 p. m.) until the use of the auditorium was demanded for another meeting at 5:30 p. in. In calling the meeting to order, D. Harrington made a few remarks as to the importance of the health dust problem in mining as well as in general industry and expressed gratification that the subject is now out in the open and that mining people are desirous of ascertaining the facts. B. F. Tillson acted as chairman of the meeting. The milling executive who desires to know what to do to prevent his workers from being unduly exposed to the dust hazard can get much out of the paper by D. E. Cummings, who has been doing much work in mines trying to keep -the dust in the air within safe limits. His recommendations indicate that the main protection of the worker in mines is by adequate ventilation, supplemented by the extensive use of water in drilling, as well as in water curtaining to condition air both in regard to dust content and to temperatures. Blasting was shown to be one of the chief causes for dust and it was recommended that whenever feasible all blasting should be delayed to the end of the working shift.

Jan 1, 1935

By AIME AIME

MANY producers have held that the only workable quicksilver ore is easily recognized by its .cinnabar content. In most cases this is true. A noticeable exception is a. particular opalite deposit where part of the ore now being mined in considerable quantity shows only the yellow mineral, calomel, or its alteration products. This mineral, on exposure to the sunlight, quickly becomes coated with gray or black layers that may be removed by scraping to reveal the yellow mineral beneath. The blackening of this mercuric chloride on exposure to sunlight shows reaction to form metallic mercury, which is usually plainly present in this class of ore.

Jan 1, 1929

By AIME AIME

MATTERS pertaining to mine ventilation were, taken up at the annual meeting Wednesday morning with E. A. Holbrook in the chair. In the absence' of its author, G. E. McElroy, the first paper, entitled "Economic Size. of Metal Mine %Airways," was read by title by the chairman. The second paper, "Intermittent Mine Ventilation," by Oscar A. Glaeser, was 'abstracted by Dan Harrington. It related to metal-mining practice, being inapplicable to coal mining, of course. B. F. Tillson asked how the ,quantity of air was measured and con- trolled in the different splits and Mr. Harrington stated that an anemometer presumably was used and that split- ting was controlled by adjusting the steel doors to the desired position by means of screws. George 'S. Rice asked if the fan were underground, and Mr. Harrington replied that it was. Although he had at, one time recommended that it be placed' on the surface, certain factors led the management to keep it underground, a. location that has several advantages in this particular case.

Jan 1, 1932

By H. Foster Bain

AFTER all, mineral sanctions are not a measure of peace, they are a measure of war, and we must regard them as such. We have had two examples now in the world-first, Italy, and secondly, Japan-where we have applied sanctions. When we got ready to apply sanctions to Italy that would hurt, they went to war. In the Far East, when we applied sanctions against Japan, in the latter part of 1941, there was a quick reaction, and the Japanese bombed Pearl Harbor.

Jan 1, 1944

By AIME AIME

H OWEVER extensively water-lines may be laid in the mine for fire fighting purposes, there are still, usually, points being worked temporarily, development, stoping or other work of a temporary or incidental nature where it is considered that the expense of laying fire-lines is not warranted. While the laying of water-lines in some sections of the mine may not be warranted, in most metal mines it is necessary to lay an air-line to all working places. In the mine of the United Verde Extension Mining Co., at Jerome, Ariz., advantage has been taken of this fact by providing a means of by-passing the water at the end of the water-line into the air-line in case an emergency arises. By this means the 2-in. air-line can be quickly converted into a water-line for fighting fire which might otherwise be beyond the reach of the water-lines.

Jan 1, 1930

By ALFRED KAUFFMAN

NO matter what position we hold, workman, foreman, superintendent, manager, president, or what not, let us fail to give or to make good products, then see how quickly we'll be called to account for- our work by the buying public. The waves of progress taught us that millions were wasted in unnecessary strikes-we also learned that many losses were due to neglect on the part of manufacturers to give the same consideration and attention to the human element of their factory as they gave to their machinery. The employees learned also that the employer was their agent who found purchasers for the product of their labor. So between the two we learned that many years of labor were needed in order for a worker to recover his wasted savings, or for the manu¬facturer to replenish his loss. Treat 'em rough, and tell 'em nothing, was not very far from the true relationship between management and employees in manufacturing plants in the early days. Today just exactly the opposite views are held by executives whose function is the handling of employees. Men today want to know what it is all about. They are intelligent enough to comprehend the facts, and to use them constructively, and it is good business to give them the information.

Jan 1, 1929

By E. A. Holbrook

LOCAL yearly taxes levied on bituminous coal lands in Pennsylvania have become a cost of first importance to the coal industry of the State. In Pennsylvania there is no State tax on real estate, but local taxation of real estate furnishes the greater part of the revenue necessary for the small governmental unit, as counties, townships, boroughs, and local school, road, and poor districts. Coal in place in the ground, whether or not title thereto has been severed from ownership of the surface, is assessed as real estate and on its supposed sale or market value. There are eight classes of counties in Pennsylvania, based on population; in populous counties of the first, second and third class, assessments are made by a county board appointed by the county commissioners and are fairly uniform throughout the county. In counties of the fourth to the eighth classes inclusive, property assessments are made by property assessors elected by and for each township within a county. In these counties the board of county commissioners acts as a board of equalization and review to hear appeals. In most counties, therefore, where there is a large unmined reserve of coal, assessments on that coal vary for each township, irrespective of the fact that the coal bed is continuous under many townships.

Jan 1, 1933

By William P. Blake

(Canal Zone Meeting, November, 1910.) A DEPOSIT of manganese-ore near Tucson, Ariz., merits notice by reason of the peculiar form in which it occurs, and as a striking. example of ore-deposition by vadose upward capillary flow of metal-bearing solutions with concentration at the surface of the country-rock. This deposit occurs at the northern end of the Coyote mountains, about 40 miles west of Tucson, upon the outcropping beds of porphyritic rock, which appear to be partly-metamorphosed strata of volcanic tufa, probably of late Secondary or of Tertiary age. The strata dip northward at a low angle, and present a series of basset-edges in parallel lines of outcrop, east and west, facing the south and extending over many acres. Successive groups of these outcrops, from 5 to 20 ft. in breadth, are coated with oxides of manganese in lustrous black films and crusts, shining in the sunlight like polished ebony, and covering the whole surface of the rock above the soil. Seen at a little distance, these croppings look like solid ledges of massive and pure ore; but closer inspection and a few blows of the hammer reveal their true nature as a superficial coating allied in origin to the blackened shining surface of rocks exposed in desert-regions, familiarly known as " desert paint" or "desert varnish,"' similar to the phenomena described by me in a former paper, but much thicker and heavier. * By reason of the death of the distinguished author, this communication, probably his last communication to technical literature, is published without revision of the proofs by him. A term first given y G. K. Gilbert. See Rocks, Rock-Weathering, and Soil; by George P. Merrill, p. 256 (New York, 1897). Superficial Blackening and Discoloration of Rocks, Especially in Desert Regions, Trans., xxxv., 371 (1905).

Sep 1, 1910

By X Li, R Chu, X Deng

The hot-dip galvanising industry is the largest consumer of zinc, with over 40 per cent of the world’s total annual production of zinc used for galvanised steel. The dross generated in the hot-dip galvanising coating process is a valuable co-product, since it contains high quantities of recyclable metal. A new method to recover the metal from the industrial galvanising dross was proposed using supergravity separation. During the hot-dip galvanising process, the presence of zinc dross has a serious impact on the surface quality of the hot-dip galvanised sheet, forming zinc dross defects. To reduce the impact of zinc dross, the zinc dross on the surface of the zinc pool needs to be manually or mechanically removed at regular intervals. However, during the dross removal process, a large amount of metal zinc is inevitably carried out, resulting in low zinc utilisation rate and high zinc loss rate. This article proposes an efficient and low-cost technology for the recycling and utilisation of hotdip galvanised dross, which uses super-gravity technology to recover hot-dip galvanised dross online. The metal in the hot-dip galvanised dross returns to the zinc pot in situ, while a small part of the dross remains in the super-gravity equipment, which can reduce the amount of zinc dross by more than 60 per cent and achieve a reduction in zinc loss from 17 per cent to less than 7 per cent.

Jun 19, 2024