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By Thomas M. Drown

IN a communication to this Institute at the Baltimore meeting, February, 1879,* on the "Determination of Silicon in Pig Iron and Steel," the method recommended was the treatment of the metal with nitric acid until action had ceased, and then evaporating with sulphuric acid until the nitric acid was nearly or quite driven off After filtration of the siliceous and carbonaceous residue, and washing with hot water and hydrochloric acid, a silica was obtained, on ignition, which was quite pure. Since this paper was read before the Institute, we have had large experience with the method, and * Transactions, vol. vii, p. 346.

Jan 1, 1880

The evaluation of suppliers of BOP linings included only magnesitic and periclase compositions. Ford utilizes some dolomitic compositions. Do you care to comment on this subject?

Jan 1, 1972

By Carville E. Sparks, Rollin Farmin

Edward Thomas (U.S. Bureau of Mines, Washington, D. C.)—This excellent article on an ingenious and successful installation of wooden rock bolts loses much of its effectiveness through an attempt by the authors to establish the general adaptability of this type of support. Possibly because they have only local experience as a guide, they imply erroneously in the first paragraph that the Bureau of Mines has been opposed to wooden bolting, although later in the article reference is made to a Bureau publication on the subject. In 1947 the Bureau of Mines decided to sponsor experiments in roof bolting in coal mines because the experience of the St. Joseph Lead Co. had indicated that this type of roof support appeared to be a roof-fall accident-prevention measure that might be adopted and also effect economies in operating cost. Justification for this belief has been borne out, particularly in coal mining. This program has been carried out under the following general program: 1—The Roof Control Section of the Bureau of Mines has advocated and initiated underground experiments under controlled conditions with many different ideas related to rock bolting since 1947. In no instance has cooperation in developing an idea been refused, no matter how ridiculous it may have seemed at first glance, if it has been requested by a mining company. 2—The Bureau of Mines has no police powers over the selection of roof-support devices and seeks none. 3—At the request of an operator, the Bureau of Mines will make comparative tests on various types of bolts underground and will submit resultant data for the operator's consideration. 4—Wherever possible, the Bureau publicizes successful installations, so that others may benefit from this experience; however, it is careful not to discriminate between manufacturers of bolts or bolt-installation equipment. Unsuccessful experiments probably should also be publicized, but from a practical standpoint it is usually not feasible. In other words, the role of the Roof Control Section of the Bureau is in line with the original purpose for which the Bureau was first organized: to serve industry through gathering, analyzing, and disseminating factual data. It would seem to be logical that the starting point for any experimentation on roof bolts in coal mines should be the time-proved practice of the

Jan 1, 1955

By J. N. Munro

At the present stage of geothermal technology and the still limited applications of geothermal energy, most of us consider any use of "things geothermal" to be something out of the ordinary. If in such a situation there can be a use of geothermal energy which is even more unusual, then the utilization of geothermal energy-or more precisely, geothermal heat--for the manufacture of salt is just such a use. This is the essence of investigations in the Fiji Islands, where experiments in the evaporation of seawater to product, salt have been conducted using geothermal heat emanating from the ground in an area of hot springs. The hot springs are located on the coast at Savusavu in a depression about GO ft wide. There are ten individual springs, but most of these are small and insignificant. The temperature of the water from these springs reaches 100°C.

Jan 9, 1964

By R. H. Sweetser

There are so many conditions affecting blast-furnace results that it is hard to get satisfactory comparative data on the working of two furnaces, and much more difficult to get comparable results from the use of two entirely different fuels. The several advantages of charcoal over coke as a blast-furnace fuel have doubtless been apparent to many managers; but probably the conditions for comparative tests of the two were never so favorable as during the year 1905, at the works of the Algoma Steel Co., Sault Ste. Marie, Ontario, which comprise two modern blast-furnaces, well equipped, though of comparat.ively small capacity. For four consecutive months one of these furnaces was run with charcoal and the other with coke. Then the charcoal-furnace ran for a while with part charcoal and part coke; and, still later, with coke only. The ore-mixtures were

Jan 1, 1909

By Hans E. Gustafsson

INTRODUCTION The Kiirunavaara iron ore mine is situated in northern Sweden about 150 km north of the Arctic Circle. The ore body has a sheetlike shape, stretches about 4000 m N-S dipping 60°E and has an average width of 85 m. The ore body is known to a depth of more than 1500 m. Mining at present has reached a depth of about 500 m. The mineral is a magnetite containing 66-68% Fe. The ore body was originally mined as an open pit from 1900-1957. From then on the mining method has been sublevel caving. Production for the last few years has been 20-25 million tons /year. Sublevel caving is a mining method with many merits. One of the most valuable is the ability of using a high degree of mechanization. Today, 25 years after sublevel caving was introduced at Kiirunavaara, the advantages of the method have been more or less exhausted, and the disadvantages are more obvious as the rock pressure increases with depth. One of the disadvantages is the high degree of waste rock in the hoisted ore. Today the waste rock content is about 25% by weight of which 20% comes from the caved rock. Second, we are calculating a relatively high loss of ore (20%). Third, selectivity is unsatisfactory when mining different grades of ore. Field testing sublevel shrinkage caving (MSTM) is primarily aimed at lowering the content of waste rock compared to sublevel caving. ECONOMIC TARGET A simple calculation shows that if the waste rock content can be lowered from 25 to 15% the operational costs of mining will be lowered by about 40 million SEK/year (US $9 million) at a production level of 20 million tons/ year. A 15% waste content is the target of the field test. In the long range a decrease in waste rock dilution will mean lower investment costs for deeper levels. DESCRIPTION OF THE MSTM MINING METHOD One reason for decision to carry out the field test was that with MSTM the development drifts from sublevel caving could be utilized and thus the project could start without delay. The only additional development work needed was the loading level. Fig. 2 shows a profile through the MSTM area 66-68% Fe. and Fig. 3 shows the loading level.

Jan 1, 1981

By V. Lessels, D. J. Buckwalter, D. H. Rose

At White Pine Copper Co.'s operation in the Upper Peninsula of Michigan, the company has been losing more than four lbs of copper in each ton of sand tailings. With an average rate of 12,000 tpd of sand going to the tailing pond daily, the company has been losing more than 14 million lbs of the red metal annually. With an eye aimed toward lessening this loss, White Pine engineers in 1959 initiated a study on techniques for recovering this "lost" copper from the sands. Inasmuch as the flotation operation was considered to be optimized, a logical approach seemed to be leaching. For various reasons ammonia, ferric chloride, acid, and biological leaching were ruled out as impracticable. This led to a consideration of cyanide leaching as practiced in the precious metals industry.

Jan 8, 1967

Geologist or Mining Engineer who has had sufficient experience to make examination of a large area and who can report upon economic value of any minerals found. Work will extend over a period of 2 or more years. Location, India. R-1660. Assistant Superintendent of malleable and gray iron foundry, young man. Must have thorough molding experience, especially on squeezers, knowledge of mixture control and operation of air furnaces, cupolas, and annealing ovens college graduate preferred. R-1727. Engineer thoroughly familiar with distilling, evaporating and drying machinery. Capable of taking charge of entire evaporator department, including engineering and selling. New Jersey. R-155C. Experimental Draftsman familiar with small automatic mechanisms, principally those produced in large quantities by punch-press methods, such as adding machines or typewriters. New York City. R-1566. Patent Draftsman.-At least 2 years' experience on perspective rend-ering of small automatic machinery. New York City. R-1570. Designer.-Familiar with hydraulic work and capable of going ahead with detail and design work without supervision. Pennsylvania. R-1575. Superintendent or Foreman. Knowledge of ceramics, clay products, electric porcelain, tile, factory materials, etc. New York State. Good salary to right man. R-1578. Designer. Experienced in designing mining machinery, including electric hoists. Canada (Quebec). R-1589. Construction and Operating Superintendent. Executive and thor-oughly experienced in the zinc melting industry. Will have charge of construction of plant and its operation. Salary $6000 to start; increase to $8000 later. India. R-1593.

Jan 11, 1919

By L. W. Sink, B. H. Kear, S. M. Copley, M. F. Hornbecker

IT is well known that under appropriate conditions of chill casting, many metals and alloys develop a columnar grain structure having a high degree of preferred orientation.' In cubic materials, this principle has been employed to produce shaped castings with a unidirectional cube oriented columnar grain structure as well as shaped single crystals with a cube axis parallel to the growth ais.' "he purpose of this note is to describe how this same principle can be enlployed to produce wires, rods, or more complex crystal Shapes with a variety of conlpositions in cube or random orientations by a single casting operation. The procedure for directional solidification of in Fig. 2. Examination under crossed polarizers indicated that the striations were a second phase (presumably the B19 phase) which frequently forms initially at primary grain boundaries and then grows toward the interior as thin ribbons. X-ray studies on filings of this alloy reannealed at 1300°C for 15 min indicated a strong pattern of the fcc phase together with a substantial pattern of the B19 phase. The un-annealed filings, however, showed only the pattern of a cold-worked, fcc structure. In these two-phase alloys it appears, therefore, that the B19 phase is transformed into a disordered fcc structure by cold-working. The mechanical properties of these alloys would be of some interest since a fcc structure might be expected to possess greater ductility than the or-thorhombic B19 structure from which it forms. The author wishes to thank Mr. Harvey Yakowitz and Mr. Richard Manuszewski for obtaining the photomicrograph in Fig. 2. This research was partially supported by Research Grant DE-02455 from the National Institute of Dental Research. columnar grained ingots involves pouring a melt into a preheated mold having a water-cooled copper chill at its base? and controlling the temperature gradient in the mold so as to maintain columnar grain growth from end to end of the ingot.4 This is illustrated schematically in Fig. l(a). It should be noted that the longitudinal temperature gradient promoting unidirectional columnar grain growth is maintained by heat loss primarily through the solidifying ingot to the chill, so that both the temperature gradient and the growth rate diminish with increasing distance from the chill. As the distance from the chill increases? the columnar structure coarsens, and the perfection in preferred orientation tends to increase progressively. Using this same procedure of gradient solidification, Fig. l(b) shows a simple scheme for producing a batch of crystals having the same cube orientation rather than an assemblage of columnar grains. Wires and rods are produced by cementing ceramic tubes to the wall of the mold. The steep temperature gradient produced in the central chamber is controlled by the mold heater to produce favorable conditions for crystal growth. Clearly the success of the operation lies in the selection of individual growing columnar grains by some kind of orifice at the base of each channel in the mold. Using simple constrictions, experience with nickel-base alloys has shown that 4 -in.-diam holes at a distance of -1 in. from the chill yield crystals within 7 deg of (100); closer control of orientation is possible by placing the crystal selector farther away from the chill.

Jan 1, 1970

By Edmund J. Pryor

DURING the war years restrictions on travel, pressure of work, and the irregular arrival of technical literature from abroad combined to severely isolate Great Britain in a period of intense war expansion of the art and practice of mineral dressing. Many British technicians were fully occupied with the day-to-day problems of improvising substitutes as regular sources of supply failed. and with mastering the strange demands and working conditions of wartime. After a long day spent between ones laboratory and production work, the rest of the waking hours were often filled with fire watching or home guard patrol activities, substituting for a night-shift manager, or "resting" in a dugout while the bombs came down. There was no time for serious study of such technical literature as survived the Atlantic crossing.

Jan 1, 1947

Jan 1, 1915

By H. W. Seamon

The data here given were obtained by 1500 tests made by the United Verde Copper Co. to determine the most economical air pressure for the operation of hammer drills under the varying conditions of use, and to investigate the variation in drilling speed at different air pressures. Twelve models of drills were used at gage pressures ranging from 40 to 130 Ib. No effort was made to harmonize theory and practice; but rather to formulate empiric rules that would cover the average variation of the results obtained. These rules on the performance of hammer drills, based on the air pressure as the main variable, however, are not necessarily of universal application, but they apparently satisfy the results obtained in this series of tests. The drilling conditions at this property vary widely; an average of twenty-one machine shifts to a 3-ft. (0.9-m.) round has been found necessary in some of the development work, while an advance of 56 ft. has been made in seven shifts in the "oxide" ground. This range precludes the adoption of one type of drill as a standard; consequently almost every kind of hammer drill sold in this country has been tested. At present, sixteen models are in use, of which two types of the heavy (150 to 160 lb.) mounted drills, one of the light mounted drill, one stoper, and two hand plugging drills are considered as standard. Method of Conducting Tests All machines were of the wet type, and were selected as being representative of the several types in use at this property; all had been in use from two to four months except the Waugh 66 and the Sullivan DX61, which were new. All machines were thoroughly overhauled before they were sent to the testing ground. Tests were made on the following machines: Ingersoll-Rand, No. 248 Leyner-Ingersoll, No. 18 Leyner-Ingersoll, No. 26 Baby Leyner, BCRW430 Jackhamer, and CCW11

Jan 1, 1922

By O. Hall

DIAMOND drilling has become a very important factor in mining. It is the most satisfactory method of obtaining proof of the existence of an orebody and of determining the character and extent of the body, in measures where a core can be made. Large investments are based on the information obtained. The method of development, the mine and reduction plants, and subsidiary essentials as railways are often built without other information. The Mond Nickel Co. has drilled about 50,000 ft. (15,240 m.) per yr. for several years and has given considerable study to the question of improving the methods and of overcoming the limitations of this means of securing information. One of the main limitations of the diamond drill has been its inability to drill a straight hole. To depths of 1000 ft. (304 in.) the deflection is often not large but all holes tend to curve and take somewhat erratic courses. A hole running at a small angle to a fissure plane tends to run, along the fissure. If the hole is at a large angle, the tendency is to penetrate the fissure plane at right angles. The face of the bit having one side in solid formation beyond the fissure, the other in the selvage of the fissure tends to turn, the rods curving to the extent of their clearance in the hole. Usually rock measures have somewhat regular fissuring or strata and holes take somewhat similar courses, usually at right angles to the fissuring or strata. Excessive pressure or short or worn core barrels increase curvature. Slow speeds, correct feeds, sharp hits, and core barrels the full size of the hit, tend to decrease curvature but do not prevent it Curvature once started increases rapidly. The disappointments from crooked holes have been numerous. Discoveries have later been found to be on the properties of others. One Canadian company had a hole, supposedly discovering ore 300 ft. (91 m.) from old workings, unexpectedly turn in 8 ft. (2.4 m.) of wooden core from a timber in the old workings.

Jan 9, 1919

By Wallace Ralston

DuRing the year of 1937, the East Texas district produced 211,194,467 hbl. of oil and marketed more than 22,329 million cu. ft. of gas; 3377 oil and gas wells were completed. During this same period 106 exploratory wells were drilled, discovering three new oil fields and one gas-distillate field. Fields East Texas Field.—The East Texas field again led the district as to production and number of wells completed. During the year, 2420 oil wells were completed, making a total of 24,382 producing wells, which produced 171,336,854 bbl. of oil, for a total of 1,156,352,834 bbl. since the beginning. During the year the average bottom-hole pressure dropped 49 lb., making the average bottom-hole pressure 1119 lb. Approximately 3500 wells are making salt water, 20 per cent of them making over 80 per cent of the water. During the month of December, the daily average production of salt water was 119,000 barrels. Talco Field, Titus and Franklin Counties.—The Talco field produced 9,780,948 bbl. of oil during the year, from 637 wells. During the year 472 wells were completed. All of the wells are pumping and 241 are making salt water. This field has followed a normal development and did not exceed the estimated number of acres reported last year. Rodessa Field, Cuss and Marion Counties.—The Rodessa field was extended about 13 miles southwest into Marion County, which added approximately 4000 acres to the field. During the year 260 wells were completed, making a total of 416 producing wells, which produced 12,646,-970 bbl. of oil. The author was unable to obtain figures for the amount of gas produced. The field has two gasoline plants, which had a daily average of 16,558,000 cu. ft. of gas during December, averaging 0.83 gal. per M cu. ft. As of Jan. 1, 31 wells were making salt water. The bottom-hole pressure varies greatly, depending upon the pay from which the well is producing. The average bottom-hole pressure from the Young

Jan 1, 1938

By Maurice Rey, H. Beavers

THROUGH circumstances connected with the war, the senior author lost his records, therefore it has been impossible to include numerical data in this paper. The arsenical quicksilver ore investigated had been roasted, with poor metallurgical results. The vapor-tension temperature curves of mercury and arsenious trioxide are similar, and the arsenical compound hampers the coalescence of mercury drops in the condenser and is the cause of large stack losses. The ore was a gray limestone carrying small amounts of carbon and mineralized with cinnabar and two arsenic minerals, realgar (As2S2) and arsenopyrite (FeAsS). The proportion of realgar often exceeded that of cinnabar; the proportion of arsenopyrite was smaller. The grade of the ore varied between 0.8 and 4 per cent Hg. The problem was to make a high-grade mercury concentrate, as free from arsenic as possible. The water used throughout the testing was hard, having a pH of about 8. FLOTATION OF REALGAR Realgar showed a very strong tendency to float. It formed a film at the surface of the pulp and floated in abundance with only pine oil. Therefore an attempt was made to float the realgar before the cinnabar, but this was not very successful; the percentage of mercury in the realgar concentrate could never be brought below 2 or 3 per cent. Cinnabar slimed easily and floated with pine oil, so that some of it always accompanied the realgar. There was also the question of the cinnabar-arsenopyrite separation. On further investigation it was found that realgar can be floated not only with pine oil but even better with a combination of hydrocarbons and pine oil. Washing the ore with ether revealed that it contained hydrocarbons, which helped to float the realgar. In this connection it belongs to the same class as carbon, sulphur and talc. It can be floated also with a xanthate, when activated by a heavy-metal salt. The conditions favoring the two types of flotation are opposed, as activation by a copper salt facilitates xanthate flotation (in fact, is even necessary to it), whereas it hinders pine oil and petroleum flotation. One type of flotation can be termed nonpolar and the other polar, a distinction that has been stressed in a previous paper.1 DEPRESSION OF REALGAR AND FLOTATION OF CINNABAR 'Many chemicals were tested in an attempt to float the cinnabar and depress the realgar. Finally starch rendered soluble with caustic soda was tried, also several grades of commercial soluble starch, and dextrin was found to be the best and the most convenient reagent. Several of these starch preparations have a strong flocculating effect on the pulp, which is a distinct disadvantage. Dextrin, with its low flocculating power, is excellent. It is noteworthy that starch preparations are also depressants for carbon and talc, so that the fact apparently has a general

Jan 1, 1941

By James A. Brierley, Corale L. Brierley

Microorganisms have been considered as agents which may be of importance in catalyzing hydrometallurgical processes for the extraction of metals from low-grade ore minerals. Various microorganisms and their role in bacterial leaching are described. Bacterial leaching as applied to copper, uranium, zinc, lead, and coal is discussed.

Jan 1, 1981

By Stefan S. Kapusniak, Nichol Riggott, Stephen F. Smith

Stability investigations have been carried out in a number of major coal mining tunnels in the U.K. using various instrumentatcon techniques. The paper describes these instrumentation methods and presents results from studies in several tunnels. Both long and short term stability aspects are discussed. Prediction of tunnel stability is examined in relation to tunnel support requirements. Computer simulation techniques are used along with actual underground measurements to identify tunnel design parameters for influencing choice of support and prediction of long term stability.

Jan 1, 1984

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 Conrad W. Stellar, John L. Paynich

Design/Build concept that provides for earliest possible completion and lowest cost is presented. Elements of the program include: joint cooperation between owner, designer and builder; schedule construction sequence; and a line budget. Benefits over lump sum contracts are reviewed.

Jan 1, 1979

By H. E. Mills

THE local auditorium of a little Alabama mining town was crowded with expectant men, women and children, as the bulletin board had announced the addition of visiting entertainers to supplement the local talent and motion pictures which usually made up the program of the regular monthly safety meeting. In the audience, near the stage, sat a group of bright-faced boys in boy scout uniforms, discussing the picture just completed. As the lights flashed on a crash and scream was heard from the outside, a shrill whistle and word of command from the scoutmaster, and five of the scouts ran out of the hall, while the mine super-intendent stepped on the stage and requested everyone to keep their seats. The scouts returned, three of them carrying a limp figure in their arms, while the other two cleared the doorway and aisle of excited spectators. They marched to the stage and, placing the apparently badly-injured boy on the floor, proceeded to give an expert demonstration of first aid to the injured. The scoutmaster then explained to the audience that the whole affair had been arranged for their benefit, and invited the local first-aid men to come up on the stage to examine and criticize the boys' work. This gave an opening for several talks on the value of first-aid training and accident prevention, which is the main object of the monthly meetings. This demonstration was given by the first-aid team of Troop One, and the entertainment was provided by members of Troop One and Twenty-eight of the Bir-mingham Scout Council, organized by the writer for the purpose of promoting interest in the welfare and safety meetings in the mining villages of the State. During the past year they have visited a number of such meet-ings and presented programs similar to the one men-tioned above. However, in order to assure a good attendance, entertainment features must also be pro-vided, and the serious part of the evening program was interspersed with excellent vocal and instrumental mu-sic, dancing and novelty acrobatic acts furnished by the visiting scouts. In addition to the numerous first-aid teams of the Birmingham Council, there are hundreds of scouts scat-tered throughout the mining district whose knowledge of first aid, safety first, life-saving, personal health and public health are a constant source of protection to their community. All of these subjects are covered by merit badge pamphlets and are required of an eagle scout.

Jan 2, 1927