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By Archibald Blue

JUST one hundred years ago, in a paper read before the Royal Society of London and published in its Transactions, Rt. Hon. Charles Greville established and named the mineral species, corundum, the crystalline oxide of aluminum; and we have it on the authority of Professor Judd that in an appendix to Greville's paper the Count de Bournon correctly defined the crystallographic characters of the species. The names of its

Jan 1, 1899

The problem of applying instrument control of variables associated with lead-zinc ore treatment has been under investigation for several years at The Zinc Corp. facilities in Broken Hill, Australia. In 1959 it was decided that there was sufficient knowledge of the problem to enable specifications to be drawn up for a system to automatically control at set conditions the roll crushing, ball milling, lead flotation and zinc flotation sections. In choosing between electrical and pneumatic control systems the broad principle was adopted that if the sensing system was pneumatic the transmission and control would also be pneumatic, whereas if electrical sensing was employed, electrical transmission and control would apply. In general. pneumatic systems were preferred owing to lack of experience with, and standardization of, the electrical systems offered at the time the specification was prepared.

Jan 12, 1964

By Robert N. McIndoo

A good tire program must begin at the top; management must have an awareness of the tremendous potential for cost saving that tires represent. At Reserve Mining Co., tires account for 33% of the cost of maintaining its 44 tractor-trailer side-dump haulers and 22% of its 32 rear-dump trucks. In comparison, engine overhauls account for only 6% of the maintenance dollar. Doubling the present engine life would save only 3%. The open-pit mine, located near Babbitt, Minn., moves about 46 million t/y with its off highway fleet. Mine roadways total in excess of 160 km (100 miles) and about 1200 tires are in active use at any given time.

Jan 3, 1978

By Alfred Wandke

The problem of vein formation has been of particular interest to the writer for years. As his work for a long time was confined largely to districts showing large deposits of copper ore, it was natural that the efficiency of replacement, as one if not the chief control of the emplacement of the ore, seemed a particularly attractive hypothesis. Of late years, in almost daily underground work in the Guanajuato district, he has collected evidence which makes it certain that in a number of cases the ore solutions were under sufficient pressure to force the rock walls apart and to hold them apart, thus offering an open space for the deposition of vein and ore-bearing material. This paper will concern itself with conditions frequently met with in hypogene ore deposits of the vein type, and will deal in particular with ore occurrence in precious-metal veins of the type classified by Lindgrenl as epithermal deposits, or metalliferous deposits formed near the surface by ascending thermal waters2 and in genetic connection with igneous rocks. To account for the emplacement of this type of ore deposit various writers have suggested the following agencies: 1. Shattering of the wall rocks. 2. Pressure of growing crystals. 3. Magmation, as treated at length by Spurr3. 4. Replacement. 5. Openings produced by folding. 6. Shearing due to gravity. 7. Shrinkage produced by the passage of pre-ore solutions. 8. Contraction joints produced by lateral secretion. To this list there may be added another agency, a discussion of which forms the basis of this paper: 9. Pressure of the ore-bearing solutions.

Jan 1, 1931

MINING AND METALLURGICAL SOCIETY OF AMERICA San Francisco Section The San Francisco Section of the Mining and Metallurgical Society of America held a joint meeting with the local section of the American Institute of Mining Engineers at the Engineers' Club, San Francisco, on Tuesday, Apr. 16, 1918. The meeting was preceded by a dinner. Letters from the parent body in NewYork asking for the consideration of the proposed bill before Congress, and an expression of opinion relative to the appointment of a Federal Administrator of Mines justified the joint meeting of the local sections of the two mining societies, in that a more representative opinion of the engineers of California could he obtained. The meeting was called to order at 7:15 P.M. by Mr. Frank H. Probert acting as Chairman. About thirty engineers were present. Mr. Probert read a letter of March 14, from Secretary Huntoon, asking that the meeting be called. He read excerpts from Bulletin 117 of February 28, 1918, of the Mining and Metallurgical Society containing a copy of the proposed bill, so that all present might be advised of its essential contents. He briefly commented on the urgent need of such legislation and invited discussion of the subject. After long and thorough discussion on the part of the members present, Professor Lawson made the following motion: I move that a resolution expressing the sense of the joint meeting of the local sections of the American Institute of Mining Engineers and Mining and Metallurgical Society of America be forwarded to the secretaries of the two societies to the effect that we heartily approve of the purpose and intention of the bill designed to promote and stimulate the production of minerals necessary for the successful prosecution of the war; and that we suggest prices should be fixed for the period of the war and two years thereafter, and that these prices, guaranteed by the Government, should apply at the nearest shipping point to place of production of the minerals. This motion was carried. The meeting then adjourned, and a telegram was sent by Mr. Probert, the Chairman, to Mr. Huntoon, notifying him of the motion that had been carried at the meeting.

Jan 7, 1918

By C. A. Heberlein

C. A. HEBERLEIN, New York, N. Y.-The results stated by Rey and Brevers are so startling that they are of great interest, as the concentration of a low percentage of cinnabar by differential flotation yields a high-grade concentrate in the presence of either arsenical or iron pyrite. The authors say: "Cyanide can thus be used to depress arsenopyrite and make a good cinnabar-arsenopyrite separation. A cinnabar-pyrite separation could probably be effected in the same way." Corrosive sublimate at the present price of mercury would be a very expensive reagent but the expense would be justifiable if a high rate of concentration could be obtained with a high extraction. On my request, special tests were made in the Punitaqui mill in Chile along the line suggested by the authors, without any improvement of either grade or extraction. As the recovery of the cinnabar in a complex sulphide of chalcopyrite and pyrite gave unsatisfactory results, I had tests made at the testing laboratory of the American Cyanamid Co. at Stamford, Conn. As these tests turned out to be highly satisfactory, not only at Stamford but later at the mine, they are presented here. [ ] The pulp had a density of 22 and a pH of 7.8. Total time of conditioning was one minute. The reagent added was Texas fuel oil, 0.116lb. of 33.7 Bé. gravity containing 0.9 per cent sulphur. Frother, 0.062 lb. of No. 5 pine oil. Rate of concentration of mercury was 25.7: 11. [ ]

Jan 1, 1941

By Nathaniel Arbiter, Edward L. Vickers

Complete automation of concentrator operations through computer control has been under increasing consideration by American engineers for several years. Although justification for full-scale automation of a mill must ultimately be economic- added profits exceeding instrumentation and development costs-the technical feasibility of automation will be determined by the availability of requisite, detailed knowledge of the various unit operations in the plant. This poses problems. BASIC PROBLEMS WHICH MUST BE CONSIDERED A hypothetical porphyry copper mill will be used here to illustrate these problems. Its flowsheet will involve: mining, crushing, storage, grinding and classification, flotation, product de-watering, and disposal.

Jan 8, 1962

By E. Miller, J. M. Eldridge, K. L. Komarek

The thermodynamic properties of- liquid Mg-Pb allojs have been determined by an isopiestic method from 18 to 42 at. pct Pb and by a thevmodynumic analysis of the phase diagram frofiz 0 to 100 at. pct Pb. In the overlapping composition range the magneszupn activity values derived by the two methods are in excellent agreement, thus mutually supporting the correctness of the Mg-Pb phase diagram previously determined by the authors and of the acticitzes deriz~ed isopiestically. SEVERAL studies have been made of the thermody-namic properties of liquid Mg-Pb alloys. Wagner and Engelhardt,1 Lantratov,2 Knappwost,3 Sryvalin et al.* and Wilson5 used the electromotive-force method, Scheil and Wolf8 and Schmahl and Sieben" applied the transpiration technique, and the present authors8 utilized the phase diagram to determine the activity of magnesium in the Mg-Pb system. The results of these studies are not in very good agreement and could not be incorporated into a general systematic analysis of the thermodynamic properties of the homologous series of the Mg-Group IV B systems Mg-Pb,8 Mg-Sn,° Mg-Ge,10and Mg-Si.11 The thermodynamic properties of the Mg-Pb system were therefore re investigated by an isopiestic technique which has been developed for similar studies in the Mg-SnB and Mg-Ge10 systems- Lead specimens, contained in iron or graphite crucibles, were heated in a temperature gradient in an evacuated and sealed titanium reaction tube and equilibrated with magnesium vapor of known vapor pressure to form alloys of compositions which depended on their temperatures, the temperature of the magnesium vapor source, and the thermodynamic properties of the system. EXPERIMENTAL PROCEDURE Magnesium (Dominion Magnesium Ltd., Toronto, Canada) of 99.99+ pct purity and lead (American Smelting and Refining Co.) of 99.999 pct purity were used. In the early experiments, Runs 2 and 3, the alloys were contained in uncovered high-purity iron crucibles. Alloys formed in the uncovered iron crucibles had to be chemically analyzed owing to the slight volatility of lead under the imposed experimental equilibration conditions. The compositions of these alloys were determined by a gravimetric analysis of lead as lead chromate. To avoid this problem, the remaining runs were made in covered graphite crucibles machined from high-density (1.92 g per cu cm) graphite rods (Basic Carbon Corp., Sanborn, N.Y.) which had a maximum ash content of less than 0.04 pct. The non- i reactivity of graphite with lead and magnesium has been previously established,' and the experimental procedure has been described in full detail.' In the runs using covered graphite crucibles it was found that the weight increases of the crucibles and their contents after equilibration equaled the magnesium contents of the alloys within the accuracy of the chemical analysis (i0.3 at. pct Pb). Clearly, the small lid openings of the graphite crucibles prevented significant lead losses during a run, and the weight increase was therefore taken as the magnesium content of the alloys. EXPERIMENTAL RESULTS At thermodynamic equilibrium the magnesium partial pressure of the specimens equaled that of the reservoir. Since the magnesium reservoir was always maintained at the temperature minimum of the system, the activity of magnesium of any specimen was given by the ratio of the magnesium reservoir pressure to the vapor pressure of pure magnesium at the specimen temperature. The standard state was chosen as liquid magnesium and the vapor pressure of liquid magnesium

Jan 1, 1968

At all business meetings of the Institute the President, or, in his absence, the First Vice-President, or, in the absence of both of them, any other Vice-President or Director, chosen by the meeting, shall preside. At all other meetings of the Institute the President, or, in his absence, one of the Vice-presidents shall preside. If none of these be present the meeting shall elect a Chairman. The President shall do and perform such other duties as may from time to time be assigned to him by resolution of the Board of Directors of the Institute. II. ORDER OF BUSINESS. At each business meeting of the Institute the order of business shall be as follows: 1. Reading of minutes of preceding meeting. 2. Report of the President. 3. Report of the Treasurer. 4. Report of the Secretary. 5. Election of Directors. 6. Reports of Standing Committees. 7. Reports of Special Committees. 8. Special Orders. 9. Miscellaneous business. This order of business may be changed at any meeting, by a vote of a majority of the Members and Associates present. At all sessions of the Institute, other than business meetings, the order of proceedings and the time of adjournment shall rest in the discretion of the presiding officer. III. SECRETARY OF THE INSTITUTE. The Secretary shall keep a record of the proceedings of all the meetings of the Institute, He shall be custodian of the corporate seal, of the minute books and of all the legal documents belonging to the Institute. He shall have charge on behalf of the Institute of all correspondence. He shall notify all Officers and Directors and all members of committees of their election and appointment; shall issue notices of all meetings of the Board, and of the annual and other business meetings of the Institute; and shall, in calling special meetings of the Directors, specify the objects of such meetings. He shall act as clerk at all the meetings of the Board of Directors and at all meetings of the Institute. The Secretary shall be custodian of all technical or scientific papers submitted to the Institute for its consideration and shall have general charge and supervision of the editing and proof-reading of all material published by the Institute, and of the distribution thereof. The Secretary shall be the custodian of all back numbers of the Transactions and other publications of the Institute. There shall be kept under his direction an account in ledger form of all such back numbers. He shall on the first day of January of each year submit to the Library Committee a statement of the number of copies of Transactions, magazines and other publications printed during the preceding year, giving the number distributed and remaining undistributed; also a statement covering additions to and withdrawals from the total stock of Institute publications, with the number remaining on hand at date of statement.

Jan 1, 1928

By D. R. Hanson

The acoustic vibrational spectra of impacted rock slabs were examined at the Denver Research Center, US Bureau of Mines, in an attempt to characterize the behavior of partially detached mine roof rocks. The ultimate goal of this study was to develop a technique or instrument that could provide a quick, accurate, quantifiable measure of mine roof stability. The power spectra of unstable rock slabs were found to contain more energy in the range of 200 to 1000 Hz than solid rock. Comparison of the power contained between 500 and 1000 Hz with that between 3000 and 3500 Hz provided a quantitative measure of rock stability. A lightweight prototype field instrument was designed, constructed, and field tested. This battery-powered instrument computes the power contained in the two frequency bands, compares their magnitude, and displays a number related to the stability of the block tested. Field tests showed the instrument provided reliable measurements of block stability even under conditions of noise that would have seriously degraded the accuracy of the standard methods of roof sounding.

Jan 1, 1986

By K. F. Unrug

Eastern coalfields have been extensively strip mined. In the past, contour mining left vast areas of post-mining highwalls and benches. Thin seams, which cannot be feasibly mined with conventional methods, quite often contain substantial reserves of high quality coal. Unconventional secondary recovery methods may permit economical production of that coal, increased use of reserves, and provide resources for restoration of orphaned land. Technical and rock mechanics implications of secondary mining methods are discussed to determine their limitations and the objectives of required research.

Jan 1, 1986

By R. H. Rice

Turbo blowers for blast-furnace blowing have now been in use for some years, and a review of the experience gained and the present state of progress may be interesting.

Jan 1, 1915

By Robert C. Collins, Clifford L. Jewett

The development and production of artificially colored roofing granules have been key factors in the success of the asphalt roofing industry. They provide protection for the asphalt from solar radiation and satisfy the home-owner's desire for a wide range of attractive colors. As a result, the asphalt shingle has become the most commonly used roofing material today. In addition to providing a stimulus to the asphalt roofing industry, artificial methods of coloring granules completely changed the nature of granule production from one of quarrying, crushing, and screening to a complex technical operation. Today's roofing granules are the result of many years of research, and they are produced in modern plants to exact specifications. History Asphalt roofing materials available today are the product of a long evolution of technological development. Forerunners of the present bituminous products, appearing as early as 1780, were primitive constructions of burlap saturated with crude tar or pitch. An early improvement to this basic effort was the dusting of talc, mica, or other finely ground material on the coated surfaces to keep the roofing from sticking to itself in storage. At times some pigmentation was added with the dusting material for initial color, but this was far from satisfactory. In fact, this early product possessed none of the qualifications of a good roof surfacing material. It was not economical; it was difficult to handle and apply; it was not attractive; it provided no resistance to fire; and it would not withstand the elements as well as other products then in use. Methods and machines were soon devised to saturate endless webs of felt with asphalt from the fast-growing petroleum industry. Even though saturated felt became available, this product of rags and wood fiber had almost the same limitations as burlap and tar. Even with heavier coatings of asphalt applied to both sides of the sheet for rigidity and longer life, the product still lacked color and fire resistance. Further, it was found that constant exposure to the sun soon caused the asphalt to become brittle, and it eventually cracked and leaked. This led to the first important use for crushed mineral products on asphalt-coated shingles and provided the key to the subsequent growth of the asphalt roofing industry. When a layer of crushed mineral was embedded in the surface exposed to the weather, the asphalt coating was protected from ultraviolet light and retained its elasticity over a much longer period of time. In addition to this protection, the mineral surfacing provided some resistance to fire. Fire resistance in the past had been found only in the expensive slate or tile roofs and the unattractive and expensive metal roof coverings which were then available. The most common mineral granule applied to the early asphalt roofing products as they began to make their first significant advances after 1900 was screened waste from slate quarries. Slate granules being available in dull shades of red, green, black, purple and a few other miscellaneous colors did provide a degree of color. Since slate has a flat platelike cleavage, it provides a cheap protective cover for the asphalt-coated sheets. Records show that coarse slate screenings were used for asphalt roofing as early as 1906. As the asphalt roofing industry developed, many other natural colored rocks and minerals were used to coat the surfaces of the roofing. The list included silica

Jan 1, 1975

NEW MEMBERS The following list comprises the names of those persons who became members during the period Dec. 10, 1918, to Jan. 10, 1919. ADAMS, W. W., Mine Supt., Cia. Minera Paloma y Cabrillas, Higueras,,Coah., Mexico. ANKENY, CLEMENT W., Golden Cycle Min. & Reduction Co., Colorado Springs, Colo. ARGUE, WILLIAM H Mech. Engr., Ohio Brass Co;, Mansfield, Ohio. ARTHUR, WALTER Chem. and Met., Garford Motor Truck Co., Lima, Ohio. BANGSER, WILLIAM, Supt., Treatment Dept., Bethlehem Steel CO., Bethlehem, Pa. BEACH, C: S Asst. Supt. and Engr., Kemmerer Coal Co., Frontier, Wyo. BEAVER, A. B., Chem. and Engr. of Tests, National Cash Register Co., Dayton, Ohio. BORRIES, WILLIAM J., Min. Engr., Gen'l Mgr., American Zinc & Slate Co., Picher, Okla. BOTSFORD, CLARENCE A., Acting Gen'1 Mgr., Mogollon Mines Co., Mogollon, N. M. BOTSFORD, GEORGE B., Asst. Supt., Sunrise Iron Mines, Colorado Fuel &. Iron Co., Sunrise,. Wyo. COLLINS, GEORGE N., Mine Shift Boss, New York & Honduras Rosario Min. Co., San Juancito, Honduras, Central America. COTS, HOMER, Resident Engr., Arkansas and Oklahoma Dist., Central Coal & Coke Co., Huntington, Ark. CRICHTON, WALTER CREIG, Min.. Engr., 20S Charleston National Bank, Charleston, W. Va.

Jan 2, 1919

By Charles O. Thompson

IN 1867 the city of Worcester walled in the Mill Brook for its main sewer. This stream, one of the important affluents of the Blackstone River, flows through the city in a southwesterly course from Salisbury Pond, and along its valley a considerable part of the heavy manufactories of the city are placed. At two points, a mile apart, a sufficient fall occurs to be turned to account for motive power, and at many points it was the right and practice of the riparian proprietors, prior to 1867, to use the water for steam and other manufacturing purposes. But the

Jan 1, 1881

record with the Royal Flying Corps was considered a remarkable one, for he was at the front within two months of the date on which he was granted a commission, during which interval he took the prescribed technical course at Oxford, and aviation training at Netheravon and Bristol. On Sept. 14, 1916, he took his first flight over the German lines, when his engine stalled and he had to volplane down, fortunately landing on the French side of the lines. On Sept. 16, he went over the lines with six others, and not returning immediately with the others, was lost. He tried to make for the sea and come back following the course of a river, but when he did descend he found that he was 60 miles west of Paris and 100 miles south of his lines. He flew over to Paris and stayed there for the night, going back to his squadron the next morning. Then on Oct. 4, he was sent up at night for the first time, and in making a landing he passed the flares just as he struck the ground, which put him in total darkness. He struck something and his machine turned a complete somersault, which accident put him in the hospital for ten days. In December, 1916, he left the 21st Squadron and was transferred to the 24th, as the 21st was made an Artillery Squadron and he preferred to remain a fighting scout. In the same month, he was made Acting Flight Commander for about 6 weeks, and about April 3, 1917, his rank of Flight Commander was confirmed. The beginning of May he started to introduce a number of new machines for his squadron, these being of an entirely new type. On May 19, he was up with one of the machines in the evening, practising sharp turns and dives, when the wings suddenly crumpled up and he fell 700 ft., being killed instantly. He was buried in a French Cemetry at Monchy Lagache about 8 miles southeast of Perronne, and about 25 miles east of Amiens. Sergeant Herbert Moore Harbach Herbert Moore Harbach was born in Lebanon, Pa., Apr. 4, 1891, graduated from the Lebanon High School in 1911, and entered State College from which he received his degree of Bachelor of Science in Metallurgical Engineering in 1915. He was employed by the Lackawanna Iron Co., at Buffalo, W. Y., and was later transferred to their Lebanon plant to start up the newly erected benzol plant. He was later made foreman of the coke ovens, which position he held after it was bought by the Bethlehem Steel Co., and until he enlisted in the service of his country in September, 1917. He was stationed at Camp Meade, Md., until the spring of 1918, when he was transferred to the C. W.

Jan 1, 1920

By B. L. Seegmiller

Horizontally stratified lithologies of certain open pit or strip mines create unique stability problems for mine operations. Such problems may result when specific lithologies, such as sandstone and shale, exist in final or long-term slopes. Slope instabilities may occur when a sandstone unit directly overlies a shale unit and ground water drains into the mine along the lithologic contact. In essence, the ground water erodes the underlying shales and undercuts the sandstone. Large sandstone blocks fail in a toppling mode and cause safety and cleanup problems. Use of rock reinforcement including chain link fencing, roof bolt mats, rock bolts, rock anchors, and shotcrete offers a possible solution to the problem.

Jan 1, 1985

Jan 1, 1934

Some 30,000 people attended from 50 countries. Over 600 exhibitors brought with them a billion dollars of mining technology, ranging from tiny high-precision valves to giant off-highway trucks. Twenty-seven technical sessions with more than 100 papers covered the gamut of mining advancements. It was a grand display of industry vitality just to power the huge exhibit area required 22,000 kW of electricity each day, and support services for the exposition created more than 1000 daily jobs for local labor. Unquestionably, Las Vagas knew the miners were in town for the American Mining Congress' International Mlining Show.

Jan 11, 1978

By A. D. S. Gillies

The effectiveness of coal mine face ventilation and the ability of airflow to maintain satisfactory methane and respirable dust levels in the working face area has been studied through the use of scale modeling techniques and underground testing procedures. In particular, consideration has been given to examination of the effects of operation of a high airflow, machine mounted dust scrubber unit on face air patterns. Results obtained through a cooperative study with the Peabody Coal Co. demonstrate that new mining cycles can be considered that increase production efficiency while maintaining satisfactory ventilation conditions.

Jan 1, 1986