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By T. L. Joseph

THE United States Bureau of Mines has been studying the blast-furnace process for, about ten years. An experimental furnace was developed by the bureau in cooperation with the Minnesota School of Mines Experiment Station, University of Minnesota. Many data have been obtained and published.1 Royster, Joseph and Kinney§(48) found that the particle size of ore had an important effect upon the blast-furnace, process. Kinney(28) stated: Economy in blast-furnace practice depends largely upon efficient gas-solid contact in the shaft of the furnace. If efficient work is not done in the shaft, the hearth and bosh will not function properly. A condition may be readily imagined where the particles of ore in the shaft are so large that the time entailed in the descent of these materials into the bosh is not sufficient to permit proper reduction and preparation prior to the time the ore enters the bosh of the furnace. Another condition may be pictured where the density of the stock column and the flow of stock is such that the ore will take one course and the gas another. Both of these examples will result in insufficient contact between the gas and the ore. Unreduced ore will reach the hearth, and the gas which has not been efficiently oxidized will reach the stock line. The result is the use of an excess of carbon in the smelting process. It is obvious that fine ore particles occurring in the ore as charged, or . formed in the furnace due to heat and mechanical action, place a definite limitation upon the efficiency of the operation. There is also an economic loss of fine material as dust.

Jan 1, 1930

William B. Phillips, Birmingham, Ala.: The analysis of Pratt coal made by myself, and given by Mr. Ormsbee in his paper (p. 113), is likely to mislead the reader as to the real nature of this coal. It represents the very purest coal that I have been able to get, and does not represent the average composition of the lump-coal as prepared for market. I wish it were true that the coal had no more than 2.50 ash and 0.83 sulphur. The analysis of McCalley is nearer the real figures than any of the others. There is no use in giving an

Jan 1, 1896

By Donald H. Beilstein

The St. Joe Minerals Corporation Lead Smelter and Refinery have been in continuous operation at Herculaneum, Missouri since 1892 as the Herculaneum Lead Smelting Division. Over the years, the plant has undergone many changes to increase production, improve the technology, reduce the cost of operations, and produce the highest grade of primary lead. The latest alterations were begun in 1950 and completed in 1970 and have resulted in the Herculaneum Smelter capacity being increased to in excess of 200,000 tons per year (180,000 metric tons). This increase has made the Herculaneum Smelter the largest in the United States, and second largest in the world. This paper will describe the Herculaneum Smelter equipment, processes, and material balances. Particular emphasis will be given to the McDowell-Wellman 10' x 100' (3 x 30 meter) up-draft sinter machine and ancillaries; to the new Heavy Smelting Department (blast furnaces and drossing section); to the new Lead Refinery and its automatic casting equipment and to the gas handling system including the 340 tons per day (305 metric) Sulfuric Acid Plant utilizing a -four pass converter. The description will include photographs, flow sheets, tonnages and assays where applicable.

Jan 1, 1970

By Geoffrey Gilbert

The material that forms the basis of this paper was collected in the spring of 1922, during a ten-day visit to Ducktown by the writer in the company of Prof. L. C. Graton. The time available for the work was far too short to allow anything like a thorough study of the deposits, and structural and stratigraphic questions, though they have an important bearing on the origin of the primary ores, were necessarily left untouched. Attention was focussed on the zone of oxidation and enrichment; and by devoting most of our time to the upper levels, open pits, and old workings, and examining the deeper levels only thoroughly enough to obtain a fair idea of the nature of the primary sulfide ore, we were able to make a reasonably complete survey of the various orebodies. With this field work for a background, the writer later made a study, in the Harvard laboratories, of the specimens obtained during the visit. As some of the facts brought to light by this study appear to be new, it seems worth while to set forth the outstanding features and a proposed explanation of them. Much of the Ducktown material that is obviously of greatest significance, as regards oxidation and enrichment, is soft and crumbly. Notwithstanding the desirability of gaining from such material all possible information as to its mineral composition and textural relationships, but little has heretofore been learned regarding it; but, by suitable preparation of this material in connection with the present study, it has been possible to examine it under the microscope without any disturbance of its texture and about as satisfactorily as if it were hard, fresh ore. The information thus gained has contributed measurably to the results set forth in this paper.

Jan 1, 1924

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS. Secretary, 55 Wall St., New York. N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. C. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2164, Spokane, Wash. C. LIVINGSTON. FRANK A. ROSS.

Jan 6, 1916

By William Newnam

WHEN Hugh Lee Pattinson discovered, in 1829, that the crystals formed during the slow cooling of molten lead were poorer, and the remaining liquid richer in silver, than the original lead, an important step was made in the metallurgy of this metal. Being the first process applicable to the desilverization of low-grade lead bullion, it soon found its way into all European countries having such a product to treat, thereby effecting the saving of many ounces of silver annually which previously had been thrown away. The old hand process was expensive, as viewed from the standpoint of more modern methods; the labor was great anti the tonnage was small, but on the other hand the results were fairly, satisfactory. This process flourished for some time after the introduction of the cheaper Parkes process in 1852 and it is still in use in a few European smelteries. Only one notable improvement was made on the original process, that of Luce and Roan at Marseilles, France. It consisted in the application of steam for stirring and the tapping of one-third of the liquid lead, through perforated plates covering the tap holes flush with the bottom of the kettle, thus leaving two-thirds in the form of crystals in the original kettle. This modification considerably lowered the operating costs as it permitted of much larger kettles, an increased tonnage and eliminated much of the slow, hard labor of the hand process.. The Luce and Rozan process has persisted in its original form to the present clay. Stephen Tredinnick, English born, spent most of his years around the Luce and Rozan plants at Marseilles and elsewhere in Europe, coming later to Eureka, Nev., in 1878, to operate the Luce and Rozan plant at that point. Mr. Tredinnick was a competent Luce and Rozan operator and being devoted to the process he firmly believed that with modifications the costs could be so lowered as eventually to supplant the Parkes process.

Jan 5, 1917

By W. C. Coffin

Fire-brick stoves have become a necessary part of the modern coke blast-furnace equipment, and are also superseding the cast-iron pipe stoves in anthracite- and charcoal-furnaces. The brick stoves in general use are of either the Cowper or Whitwell type, or modifications of these bearing the names of those who invented the alterations from the original types rather than any real departure from then]. All these stoves have approximately the same valve-equipment and follow the same line of operation. The waste gas from the furnace enters at one port and burns in a single combustion-chamber, and the heated products are drawn through the various passe; in the brickwork to a stack of proper height to create the necessary draught. The last passes of these stoves receive a very small percentage of the heat from the gas, owing to their extreme distance from the combustion-chamber; and this chamber also suffers great deterioration in the attempt to force the heat into the farthest passes. At best, about 70 per cent. of the heat taken up is held in the combustion-chamher and the first down-pass of the Whitwell stoves. Mr. Hugh Kennedy, Manager of the Isabella Furnaces, Pittsburgh, Pa., who has had a large experience with the fire-brick hotblast stoves, was so strongly impressed with the fact that but about thirty per cent of the brick of the average stove were doing proper duty as heat-agents, that, after careful study and experiment, he had three 20- by 60-feet stoves constructed with a view of more uniformly heating all the brick. In these the general lines of the Whitwell stove are followed, with the blast-connections unaltered, but gas is introduced at the bottom of each pass, and outlets are provided at the top, so that the gases have a direct natural draught in each pass and the highest heats are obtained at the bottom instead of the top. The natural tendency being toward the reverse condition, the brickwork soon acquires an almost uniform temperature.

Jan 1, 1893

By F. F. Aplan, D. W. Fuerstenau

This chapter presents modern concepts of the flotation of nonmetallic minerals. In particular, it is concerned with such minerals as metal oxides, silicates, sulfates, carbonates, and halides. It is not the purpose to duplicate the two excellent, recent treatises by Gaudin l and by Sutherland and ark,^ but rather to expand their correlations of data, particularly in view of recent, ex- citing new experiments which are shedding new light on the principles of non- metallic flotation. Outstanding success has been achieved over the past 50 years in separating one sulfide from another or from the gangue constituents using a minimal amount of reagents. In contrast to this, selective flotation in nonmetallic systems is often difficult in that one class of compounds alone, the carboxylic acids, may float nearly the entire array of nonmetallic minerals under the appropriate conditions. Moreover, while lime, cyanide, sodium sulfide, and copper sulfate constitute the principal modifiers used to obtain selectivity among the various sulfides, the nonmetallic mineral flotation engineer is con- fronted with a vast array of modifying reagents. In sulfide and native-metal flotation, a strong chemical adsorptive bond is generally formed between the mineral and sulfhydral collector. In fact, re- cent radio-tracer studies show that below monolayer coverage as much as 98% of added mercaptan is adsorbed on the surface of gold.? Contrasted to this, Bloecher's data indicate that for the quartz-amine system only about 60% of the collector is adsorbed.4 This greater residual concentration in the solution results from weaker forces of adsorption in the quartz-amine system. In the flotation of nonmetallic oxide minerals, collector adsorption results from rather weak physical forces, primarily electrostatic attraction and van der Waals attraction between hydrocarbon chains. In the flotation of salt-type minerals, carboxylic acids are adsorbed both by physical and chemical forces. It is a study of the effect of the electrical forces superimposed on the chemical adsorptive forces that contributes most toward understanding nonmetallic mineral flotation. The need for quantification of general rules for the flotation of nonmetallic minerals is so great that Taggart 5 with unmasked sarcasm suggested that after trying anionic and cationic collectors:

Jan 1, 1962

By R. W. Smith, R. W. Lai

Very recently there has been a quickening of research effort in the field of silicate mineral flotation, particularly as regards the flotation of beryl.' These studies have already contributed much to the understanding of both anionic and cat-ionic flotation of silicates. Of particular interest concerning anionic flotation has been the work done on heavy metal activation of silicates by M. C. Fuerstenau and co-workers.4,7 In addition. in the paper by Fuerstenau, Rice, Somasundaran and Fuerstenau7 attention was paid to low pH anionic flotation of beryl in the absence of activators. This subject was also covered in the papers by Avotins,3

Jan 1, 1967

By Gerald Edmunds, R. K. Waring, E. A. Anderson

Brass is liable to failure under the combined influence of stress, certain corrosion media, and time, a phenomenon commonly termed season cracking or stress-corrosion cracking. The consequences of this are serious in applications of brass generally, including the important field of cartridge cases. Cartridge cases (70 Cu: 30 Zn) that fail from this cause may allow the escape of gas from the gun breech, a hazard to the shooter, and may not eject, thus temporarily putting the gun out of action. In loaded cartridge cases, the stress present is partly residual from the, drawing and necking operations and partly applied by the insertion of the projectile. Ammonia, present as a decomposition product of smokeless powder, air and moisture constitute corrosive media. The prevalence of season cracking has been reduced considerably, but not eliminated, during the past quarter of a century by low-temperature annealing to relieve stresses residual from fabrication, a method suggested by Diegel 38 yr. ago(I).2

Jan 1, 1945

By Howard R. Keil

CARLTON mill in the Cripple Creek district, 45 miles southwest of Colorado Springs, Colo., has been in operation for approximately three years, treating the custom sulpho-telluride ores formerly handled by the Golden Cycle mill in Colorado Springs. At the new mill the pyrite-telluride flotation concentrates have been roasted, prior to cyanidation, in a Dorrco FluoSolids reactor, which has proved capable of yielding calcine readily amenable to cyanidation. Incoming ores are crushed at Carlton to 5/8 in. and sampled in 30 to 75-ton lots before the individual lots are mixed in the fine ore bin. The composite ore then goes to the grinding circuit. Classifier overflow from the grinding circuit is treated by flotation to produce a concentrate containing approximately 85 pct of the values in 5 pct of the weight. The flotation concentrate goes to the FluoSolids reactor prior to cyanidation. Cyanide solution values are recovered by zinc dust precipitation. Flotation tailings are thickened and cyanided, the values from this part of the circuit being recovered from solution by activated carbon.

Jan 12, 1954

By George S. Rice

Those who for the first time see, at a mine, a great hole caused by subsidence; or, going underground, see an extensive fall of roof or hanging wall are apt to regard such an occurrence as an accident and not a normal condition of exhaustive mining. Moreover, the public is inclined to believe that a cave or subsidence of the surface is the result of carelcssness in mining or the rapacity of the mine operators in "robbing pillars," a tern too loosely used in descriptions of coal mining. This belief is fostered by the common-law requirement that an owner of the surface or of surface improvements is entitled to full support of the surface. Court decisions have upheld this law even when that owner has sold or leased the underlying mineral, unless a clause in the sale or lease contract exempts the mining company from paying the owner of the surface for damages that may result from mining. Another reason for this belief is the earlier practice (which is still extensively followed in this country) of leaving all coal pillars unmined, except as they have been thinned by so-called robbing; by not extracting the pillars, the surface may be supported by them for years, perhaps for generations. Inasmuch as the practice of leaving permanently in the mines from one-third to one-half of the mineral is wrong, with respect to conservation of a national resource, it behooves the mining engineers to assemble data and disseminate information on the subject, pointing out that subsidence must follow complete extraction, unless expensive methods of back-filling are employed, such as are used in Germany and France. These methods inevitably increase the cost of mining and the price of the mineral produced. It is popular to speak of "waste in mining" without a realization that much so-called wasting is unavoidable unless subsidence is accepted and provision made therefor where the surface is valuable, or else the only present known alternative of hydraulically placing sand or crushed stone filling in the excavations, at an increased cost of the mineral product to the consumer.

Jan 1, 1923

By George S. Rice

Those who for the first time see, at a mine, a great hole caused by subsidence; or, going underground, see an extensive fall of roof or hanging wall are apt to regard such an occurrence as an accident and not a normal condition of exhaustive mining. Moreover, the public is inclined to believe that a cave or subsidence of the surface is the result of carelcssness in mining or the rapacity of the mine operators in "robbing pillars," a tern too loosely used in descriptions of coal mining. This belief is fostered by the common-law requirement that an owner of the surface or of surface improvements is entitled to full support of the surface. Court decisions have upheld this law even when that owner has sold or leased the underlying mineral, unless a clause in the sale or lease contract exempts the mining company from paying the owner of the surface for damages that may result from mining. Another reason for this belief is the earlier practice (which is still extensively followed in this country) of leaving all coal pillars unmined, except as they have been thinned by so-called robbing; by not extracting the pillars, the surface may be supported by them for years, perhaps for generations. Inasmuch as the practice of leaving permanently in the mines from one-third to one-half of the mineral is wrong, with respect to conservation of a national resource, it behooves the mining engineers to assemble data and disseminate information on the subject, pointing out that subsidence must follow complete extraction, unless expensive methods of back-filling are employed, such as are used in Germany and France. These methods inevitably increase the cost of mining and the price of the mineral produced. It is popular to speak of "waste in mining" without a realization that much so-called wasting is unavoidable unless subsidence is accepted and provision made therefor where the surface is valuable, or else the only present known alternative of hydraulically placing sand or crushed stone filling in the excavations, at an increased cost of the mineral product to the consumer.

Jan 1, 1923

By Howard R. Hughes

In drilling for water and oil to reasonable depths through the generally soft yielding clay and sand formation of the Coastal Plain of Texas, Louisiana, and Mississippi, the rotating method of drilling was adopted, principally on account of the easy and quick penetration, and the low cost of the drilling plant. In favorable ground, free of heavy gravel and rock strata, as much as 1,600 ft. has been drilled in less than 36 hr., although such performances were of course rare. Hydraulic rotary drilling, or, as it is now called, rotary drilling, was used in the above States as early as 1880. The plant consisted of an ordinary derrick, a 25-h.p. boiler, a small hoist, a steam pump, and a water swivel with hose attachment, and an ordinary flat diamond-pointed bit. The successful drilling in of a phenomenal oil well by this process on Spindletop, near Beaumont, Texas, on Jan. 10, 1901, and the ascertained impracticability of drilling subsequent wells in the same locality by other methods (owing principally to heavy quicksand under pressure from below), brought rotary drilling into great prominence, practically to the exclusion of any other process throughout the Coastal Plain, and later on elsewhere. The method, as its name implies, involves the rotation of a pipe by means of machinery placed on the derrick floor. A drill bit attached to the lower end cuts a clearance for the drill pipe, with much the same motion and effect as an auger. Water forced through the drill pipe by means of a pump, and escaping through the bit, removes the cuttings and returns to the surface outside the drill pipe. In this manner the hole is kept open, permitting the drill stem to rotate freely. The pressure of the column of muddy water holds up the walls of the hole until it has been cased. Practically all the wells of the Gulf coast region, numbering nearly 10,000, have been drilled with this system. During the last five years its use has been extended to many other States and countries.

Jan 1, 1915

By Jr. Baldwin. William M

WELL known to every metallurgist is the fact that different production schedules will profoundly affect the character of annealed metal strip. Yet the number of conditions [ ] that may be wrought by different combinations of rolling and annealing schedules is so myriad that despite the continual research that is being applied to this subject, the complete picture is not yet known. Copper, like all other metals, during the process of rolling or annealing, develops certain crystallographic configurations which should not be dismissed as being too impractical, for the crystallographic condition existing within the metal is a principal influence upon both the external mechanical properties and the behavior of the material [ ] when it is subjected to such operations as bending, flanging, drawing, and so forth. EFFECT OF ROLLING AND ANNEALING UPON THE CRYSTALLOGRAPHY OF COPPER STRIP The most salient points in the crystallographic reactions of polycrystalline copper to rolling and annealing may be best represented graphically by a "map" such as that given in Fig. I. I. As copper strip is cold-rolled from a randomly oriented structure (pole figure I),

Jan 1, 1942

By R. M. Schuller, J. J. Suloway, W. F. Childers, R. A. Griffin, S. J. Russell

Seven solid wastes from coal conversion processes were characterized chemically and mineralogically. The wastes included three Lurgi gasification ashes, two liquefaction residues (SRC and H-coal), a fly ash, and a water-quenched slag. Leachates generated from the solid wastes at various pH levels over the range 2.5 to 11.0 were analyzed for over 40 constituents. Results of the leachate analyses demonstrate the wide variation in constituent solubility for the solid wastes. To help assess the environmental impact of the disposal of these wastes, the leachates were also employed in soil attenuation studies and acute 96-hr static bioassays using young fathead minnows.

Jan 1, 1981

By S. Clark Komardi

Freeport Indonesia, Incorporated produces 180,000 tons per year (200,000 STPY) of 32% copper concentrate. A 111 kilometer (69 mile) pipeline transports the concentrate slurry to the sea coast. Rheology characteristics of the concentrate slurry must be monitored continuously to assure that the pipeline does not plug and that mini- mum degradation of the pipeline occurs. Factors affecting the rheobgy include particle size, percent solids, pH, and reagent additions. This paper includes a general pipeline description, slurry rheology factors affecting operations, and the problems encountered and their subsequent resolution. Six years successful operation of the worlds longest copper concentrate slurry pipeline has provided a unique insight into slurry behavior.

Jan 1, 1980

By R. L. Curfman

From January 1, 1965 through July 5, 1970, the very difficult potash ore body of Texasgulf Inc. near Moab, Utah was mined by conventional methods. The mine was gassy, the temperature was high and structural conditions precluded a satisfactory or economical extraction ratio due to the undulating configuration of the ore horizon. In 1966, 67, and 68, alternative mining methods were considered, among which was solution mining of the ore body. Cost studies indicated that the use of crystallizers to evaporate the large amounts of water attendant to solution mining offered no chance of economic success. In 1969 additional testwork and cost studies were carried out utilizing solar evaporation. These studies showed economic potential and justified additional investigation. As a result of these studies, Texasgulf now gathers potash solids from these solar evaporation ponds, (Fig. l), after pumping them from the underground mine as brine. The investigations were concentrated in four basic areas : (1) area evaporation rates and crystal growth habits; (2) underground solution tests including heat transfer rates; (3) accelerated evaporation tests to provide material for metallurgical testing, and (4) tests of evaporation pond lining materials and application techniques, along with area surveys to ascertain if sufficient earth was available in the near vicinity to con-

Jan 1, 1974

By James E. Dunn

For several years, ground support at the Pitch uranium mine has been a serious headache to the management. The "moving" ground raised havoc with standard timber sets as well as steel sets. The author discusses this problem which has led to the adoption of heavy cribbing practices in drifts and raises.

Jan 6, 1961

By Dever C. Ashmead

Anthracite was first mined in the Wyoming Valley and sold as an article of commerce in 1808. As some preparation has always been necessary to make it ready to burn, the preparation of anthracite must date back over a hundred years. Two vital factors have determined to a large extent the degree and the method of anthracite preparation. These are, first, the character of the beds worked and the methods by which they are mined and, second, the equipment used and practices followed in the burning of the coal. It is not the intention here to go deeply into these phases of preparation as a paper of no mean length could be prepared on the history of either. Rather, the intention here is to point out the main considerations and to show the influence they have exerted on the preparation of anthracitc. Mining Methods and Their Relation to Preparation In the beginning of the nineteenth century, the coal beds were virgin with the possible exception of some outcroppings that had been worked, to a slight extent, by the Indians. It is known that the American aborigines had a, knowledge of the use of this fuel, because when the Wyoming Valley was purchased from them, in 1754, they mentioned the fact that, by selling the land, they would lose their coal. Real mining of anthracite began about 1808 when Judge Jesse Fell, of Wilkes-Barre, discovered that the "common stone coal of the valley" could be burned in an open grate. For some years thereafter mining was conducted near the surface. The working p1aces were driven narrow; only the best of the coal was selected and the remainder was left in the ground. Only the lumps could be used, as no market existed for other sizes. As time passed, however, it became necessary either to go farther into the ground or to widen the working places. When these places were widened, falls of roof were apt to occur, making it necessary

Jan 1, 1922