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By W. D. Walker

The trend toward encouragement of worker participation in accident prevention in the coal mines of the United States is not new; however, it has been given added impetus in recent years and is now definitely progressing. It has been found by experience that, although there are many approaches to a mine-safety program that will include the workers themselves as well as their supervisors, no one way is suitable under all circumstances. It requires the concerted efforts of many agencies working along parallel lines toward a common goal. The following seven principal agencies, using somewhat different methods, are listed to illustrate how this problem is approached throughout the coal-mining industry 1. Federal Bureau of Mines. 2. State mining departments (in individual States where coal is produced). 3. Programs conducted by individual mine operators. 4. Programs conducted by mine workers' organizations (unions). 5. Institutes, societies, and other educational organizations. 6. Coal operators' associations (regional and national). 7. Universities, college, and high schools. Each of the seven approaches to safety are discussed briefly, and their methods end contributions, such as publications and other activities, are listed.

Jan 1, 1953

By Z. Pilecki

This work concerns the identification of weak zones in the structure of a rock mass endangered by outburst of gases and rocks in the Rudna copper ore mine at greater depths (approximately 1200 m). A special methodology has been undertaken for the recognition of that threat in the wake of an outburst in the mine in 2009. No similar phenomena have been previously recorded in KGHM Polska Miedz copper ore mines. The research described in this paper was carried out in the new part of the deposit prepared for mining. Geophysical methods were used: seismic tomography and borehole ground penetrating radar (BGPR), along with particular identifications using geological engineering methods. In the researched area, Permian layers of sandstone and shale clay (Weissliegendes formation) and of Zechstein dolomite (top of Rotliegend formation) and anhydrite occur in the copper ore deposit. The rock layers are characterized by variable thickness and intensity of mineralization, varying internal structure, and local fracturing containing different gases and water. It is assumed that accumulation of gases occurs in the tectonically fractured dolomite. The study was focused on the recognition of the structure and properties of the dolomite layer lying directly within the roof of excavations. The first tests were performed with seismic tomography for the recognition of anomalous changes in the elastic properties of the rock mass. The results of these studies were used to design a control borehole for a detailed geological engineering assessment and BGPR surveys with 100MHz antennas. Seismic tomography enabled the identification of changes in Pwave and S-wave velocity, the Vp/Vs ratio, dynamic Poisson's ratio and dynamic Young's modulus. It was clear that seismic anomalies required verification by other methods. The BGPR survey was performed in a specially designed borehole, passing through the selected seismic anomalies. While the borehole was being drilled, the outflow of gases was identified, with varying amounts of CH4, CO2, and H2S detected, as well as water outflow. The results of BGPR confirmed the location of a reservoir of water and gases, about 30 m in length, found in layer of dolomite. The direct cause of the BGPR anomaly was assumed to be intensive fracturing, a greater content of clay material in the dolomite, and the presence of water in the fractured zone. The BGPR image was correlated with information on lithology, fracturing based on the RQD index and additional information acquired during drilling about water and gases surveys and other symptoms. The achieved results also showed a very strong correlation between the location of the zone containing gases and water and the anomalous S-wave velocity and field of dynamic Poisson?s ratio, and to a lesser extent other seismic parameters. It was found that the other measured seismic anomalies may be of the same nature as those identified in the control borehole and accordingly will require the implementation of detailed identification. The performed tests have also shown the usefulness of geophysical methods to identify geodynamic hazards under the geological and mining conditions of the copper ore deposit in the Rudna mine.

Aug 1, 2013

By James A. Nunn

Location Xiaolangdi is located in the Henan province of the People’s Republic of China. The distance between Xiaolangdi and the capital of Henan, Zhengzhou, is about200 km. Xiaolangdi is located on the Yellow River at the end of its big characteristic knee. It can be easily found on the map by locating Luoyang. The closest big city to Xiaolangdi is Luoyang (about 45 km). This city has about1 million inhabitants and is well known also to foreigners for its famous historical past. It has been the capital of China through 10 dynasties in former times. Overview The Xiaolangdi Multipurpose Dam Project is located at the last gorge of the middle reach of the Yellow River. The main purposes of the project are: -flood control, - ice jam control, - sediment control, - irrigation, - water supply, - hydroelectric power generation. The project consists of many structures, these are 10 intake towers, 9 flood &sediment tunnels, 6 power tunnels, 1 underground powerhouse, and 1 zone dearth and rockfill dam with a sloping impervious core, 154m high, with a crest length of 1317m. The powerhouse mainly features 6 turbine and generator units of 300 MW, totalling installed capacity of 1800 MW and annual energy output of5.1 GWH. The total storage capacity of the reservoir is 12.65 billion m³ of which 5.1billion m³ is live storage. Of the Yellow River drainage basin, 694,000 km2 or 92,3percent is located upstream of Xiaolangdi Dam Site. Xiaolangdi is located in a key position for flood and sediment control of the Yellow River. Upon completion, Xiaolangdi Dam and Reservoir will effectively mitigate catastrophic floods, the control level will be increased from the present less than 100-year return period up to 10,000 years. Also, it will reduce severe flooding of the river bed of the lower

Jan 1, 1999

By William Seymour

"INTRODUCTION Byproduct-coke manufacture is one of our country's most essential in¬dustries; its importance was strikingly accentuated by the demands of World War II. This paper reviews recent progress in various phases of byproduct-coke operations for the production of metallurgical coke particularly that used as blast-furnace fuel.In the early days of the by-product-coke industry in the United States high-grade bituminous coking coals, both high-volatile or gas coal and low-volatile Pocahontas coal, were plentiful, and the selection and mixing of coals for coke-oven use were minor problems.The demands of World War I for the production of iron, steel, and coke aroused and stimulated new interest in the investigation of the reserves, characteristics, and properties of our coking coals. During that war the increased demand for coke reached a critical stage, and the shortage of high-grade coking coals necessitated the use of cols of inferior quality and of different coking characteristics than those previously used.The period of prosperity following World War I brought much progress and development in the by-product-coke industry. Methods of testing coal and coke were improved. The search for satisfactory coking coals was continued, and construction and design of byproduct ovens were improved."

Jun 1, 1946

By H. V. Winchell

An examination of the Pachucal and El Oro districts in July, 1920, although cursory and incomplete, disclosed facts of more than passing interest to the student of ore deposits; and inasmuch as the literature on these districts is limited and some of their features are little understood, a brief account may prove valuable as reconnaissance observations to be amplified by more thorough and competent observers in the future. Where no complete monograph of important mining camps has been published a partial presentation of the data is often useful, as it sometimes leads to fuller and more accurate descriptions, by stimulating discussion. The following notes are presented with the consent of A. F. Main, managing director of the El Oro Mining and Railway Co., whose fund of information and wide acquaintance with both districts alone made it possible to cover so much ground in a short time. I have also to acknowledge gratefully the aid of C. A. Lantz and D. S. Calland of the Santa Gertrudis and Real del Monte companies, respectively, in connection with permission to inspect geological features of interest in their mines. Pachuca, Hidalgo, Mex. This mining camp has been described by Ezequiel Ordonez2 and by A. F. J. Bordeaux.3 Reported to have been discovered in 1522, it has produced silver valued at between $250,000,000 and $375,000,000. Subsequent to the discovery here, by B. de Medina, of the patio process. in 1557, its production was increased, and now, using cyanidation, the output of the camp is nearly one-sixth of the production of the world. Topography and Climate The Pachuca district consists of a series of mountains and valleys, the minor features of which extend in an easterly and westerly direction and reach elevations of 8000 to 10,000 ft. (2438 to 3048 m.) above the

Jan 1, 1922

By J. S. Marsh

Joseph Priestley prepared oxygen on Aug. I, 1774, and noted with great surprise "that a candle burned in this air with a remarkable brilliant flame." On Aug. 2, 1774, some ironmaker possibly began to wonder if this substance could be used to increase his rate of production; at any rate, there is no disputing the fact that the notion of using oxygen for steelmaking in concentrations greater than that available in great abundance—as air—has been in existence for years. Action was delayed by the lack of enough oxygen at a cost within reach of the steelmaker. Within the last several years enough has been available to permit large-scale tests of its use for both combustion, with which this paper is concerned, and for decarburization. The literature is now enormous and easily available; it is sufficient here to cite three items of historic importance in that all are about 25 years old and in that all are remarkably consistent as far as they go, with what is known today.1,2,3 Significance of High-temperature Heat The principal function of the open-hearth furnace is to supply sufficient high-temperature heat to melt the charge and then to increase its temperature to a range suitable for tapping, ordinarily in the neighborhood of 2900°F. That heat is required to make steel is understood by everybody; however, there seems to be some confusion now and then about the significance of high-temperature heat. Transfer of energy—and heat is energy— is always from a point of higher potential to a point of lower potential and, other things being equal, the greater the potential difference, the greater is the rate of transfer of energy. In the open hearth the flame, of course, is the high-potential source. Perhaps the most satisfactory approach is through the notion of theoretical flame temperature, which is the ratio of heat input to the heat content of the combustion products,* the former is composed mainly of heat of combustion of the fuel plus sensible heat of the fuel plus sensible heat of the combustion air. Thus, flame temperature can be increased by increasing the value of the numerator, by decreasing the value of the denominator, or both. The first method is as old as the open-hearth process and, of course, makes use of preheated air; its possibilities have been by no means exhausted. The second method can be put into effect only by changing the composition of the combustion air, since the combustion of a given quantity of fuel produces a definite quantity of product, and since the denominator includes the non-reactive fraction of the air, principally nitrogen. In other words, the denominator consists of the volume of exit gas multiplied by its heat capacity and that volume consists of carbon dioxide and water vapor as reaction

Jan 1, 1949

By J. S. Marsh

Joseph Priestley prepared oxygen on Aug. I, 1774, and noted with great surprise "that a candle burned in this air with a remarkable brilliant flame." On Aug. 2, 1774, some ironmaker possibly began to wonder if this substance could be used to increase his rate of production; at any rate, there is no disputing the fact that the notion of using oxygen for steelmaking in concentrations greater than that available in great abundance—as air—has been in existence for years. Action was delayed by the lack of enough oxygen at a cost within reach of the steelmaker. Within the last several years enough has been available to permit large-scale tests of its use for both combustion, with which this paper is concerned, and for decarburization. The literature is now enormous and easily available; it is sufficient here to cite three items of historic importance in that all are about 25 years old and in that all are remarkably consistent as far as they go, with what is known today.1,2,3 Significance of High-temperature Heat The principal function of the open-hearth furnace is to supply sufficient high-temperature heat to melt the charge and then to increase its temperature to a range suitable for tapping, ordinarily in the neighborhood of 2900°F. That heat is required to make steel is understood by everybody; however, there seems to be some confusion now and then about the significance of high-temperature heat. Transfer of energy—and heat is energy— is always from a point of higher potential to a point of lower potential and, other things being equal, the greater the potential difference, the greater is the rate of transfer of energy. In the open hearth the flame, of course, is the high-potential source. Perhaps the most satisfactory approach is through the notion of theoretical flame temperature, which is the ratio of heat input to the heat content of the combustion products,* the former is composed mainly of heat of combustion of the fuel plus sensible heat of the fuel plus sensible heat of the combustion air. Thus, flame temperature can be increased by increasing the value of the numerator, by decreasing the value of the denominator, or both. The first method is as old as the open-hearth process and, of course, makes use of preheated air; its possibilities have been by no means exhausted. The second method can be put into effect only by changing the composition of the combustion air, since the combustion of a given quantity of fuel produces a definite quantity of product, and since the denominator includes the non-reactive fraction of the air, principally nitrogen. In other words, the denominator consists of the volume of exit gas multiplied by its heat capacity and that volume consists of carbon dioxide and water vapor as reaction

Jan 1, 1949

By George Hallerman, R. J. Gray

In the customary method of studying age hardening, the process of aging is interrupted by cooling the specimen and measuring its room-temperature hardness. However, the aging process may be conveniently measured while it is occurring at an elevated temperature by a series of hardness measurements at suitable time intervals. The latter method gives data void of complications that might result from processes occurring during the quench, and the data may be more indicative of the alloy's properties at elevated temperatures. The elevated-temperature hardness tester1 used in the present study employed a dead-weight loading system with a synthetic sapphire Vickers-type in-denter mounted in a molybdenum holder. The tests were performed in a vacuum of l0 to 10 torr. Hardness impressions were made by applying a 2-kg load for 15 sec. Although the hardness impressions made in the tester at elevated temperatures were measured at room temperature, the correction for thermal contraction during cooling was insignificant and therefore neglected. The two methods of obtaining age-hardening data were compared using eighteen samples of Haynes alloy No. 25* which had been annealed for 2 hr at 2250°F (1232°C). The test surfaces of the 1 by 1 by 1/4-in. samples were ground and then polished on vibratory polishers2 prior to testing. Three groups of five samples were aged at 1400°, 1650°, and 1800°F (760°, 899", and 982°C) for 4, 16, 32, 64, and 100 hr and then water-quenched. Room-temperature hardness as a function of aging time for these samples is shown in the broken lines of Fig. 1. Only one sample for each of the three temperatures was necessary to determine the hardness of the alloy at the aging temperatures with the elevated hardness tester. The specimens were heated isothermally and hardness impressions were made after various time intervals up to 100 hr. The results of these determinations were represented by solid lines in Fig. 1. Comparison of the two sets of curves shows, as expected, the hardness values determined at the aging temperatures are lower than the room-temperature hardness of the quenched specimens and the hot-hardness values reflect a strong tempera-

Jan 1, 1964

By C. W., Davie

"DEFINITIONDiatomaceous earth consists almost entirely of the silicious remains of minute flowerless aquatic plants known as diatoms. The name diatomaceous earth, therefore, is to be preferred to others such as trade names, inappropriate terms, or names correctly applied to some other product. The following names should, therefore, not be used for diatomaceous earth,-- kieselguhr, infusorial earth, diatomite, celite, moler, bergnehl, English rottenstone, tripoli, tripolite, fossil earth, desmid earth, white peat, tellurine, randanite, ceyssatite, or any trade name.FORMATIONDiatoms live in practically all kinds of water, fresh or salt, hot or cold, still or running and under different conditions of depth and pressure. These minute plants assimilate inorganic salts from their environment and produce skeletons of silica much as mollusks secrete lime and form their Shalls. When the diatoms die they settle to the bottom together with anything else which may be present, such as sand, clay or volcanic ash. The organic matter gradually disappears leaving the silicious skeletons of the diatoms which, with impurities, make up the deposits of diatomaceous earth. These deposits which are still being foamed at the present time and which were produced throughout very different epochs, were more prolifically formed in the Tertiary, so that the thickest beds so far discovered are of that Age."

Nov 1, 1925

By P. E. Damon

An arsenal of isotopic techniques is avail-able that can date the full range of hydrothermal ore deposits. The following are prerequisites for ideal results: (1) Careful collection of samples that are related to the event in a field and process context; (2) Optical examination of the component selected for dating to be sure that it has not been altered; (3) Careful preparation of a pure component of the sample selected for dating; (4) Precise and accurate measurement; (5) Knowledgeable interpretation of the data with reference to decay systematics, properties of the component analyzed as well as the field context and thermochemical environment of the ore process.

Jan 1, 1992

By L Dzinza, K C. Corin, M Tadie

The recycling of process water comes with increased electrolyte concentrations that affect water quality, which may in turn affect the flotation performance of valuable minerals (Hirajima et al, 2016). Electrolytes such as Ca2+, SO4 2- , Mg2+ and S2O3 2- have been surmised to have an impact on the action of flotation reagents such as collectors (Ikumapayi et al, 2012). Xanthate collectors are known to play a significant role in imparting hydrophobicity on mineral surfaces to enhance their flotation. The interaction between minerals and xanthates is well known to be electrochemical in nature. Such redox processes may be elucidated by electrochemical techniques. Since the mechanisms involving the interactions between electrolytes in process water with sulfide minerals and the subsequent adsorption kinetics of collectors are not well understood, this study therefore aims to provide fundamental knowledge to unpack the mechanisms involved when electrolytes interact with Platinum Group Minerals (PGMs) and how these interactions may affect xanthate adsorption. The interaction of sodium iso-butyl xanthate (SIBX) in the presence of electrolytes at increasing ionic strength was investigated by rest potential measurements, to explain the impact of electrolytes on the adsorption of SIBX on PGMs in the flotation process. Rest potential measurements for PdTe2 and PdS were conducted in an air saturated 0.05 M di-sodium tetraborate decahydrate solution, in the absence and presence of SIBX and electrolytes. It was found that the existence of sulfide and telluride on palladium affects the mechanisms in which electrolytes interact with Pd mineral surfaces. An increase in the ionic strength of Na2S2O3, CaCl2 and MgCl2, increased the interaction between the salts and PdS, thus decreasing the extent to which SIBX interacted with PdS. An increase in ionic strength for Na2S2O3 increased the interaction between Na2S2O3 and PdTe2 and therefore decreased the extent to which SIBX interacted with PdTe2. Other salts investigated in this study increased the rate of oxidation of PdTe2 with an increase in ionic strength thereby enhancing the interaction of SIBX and PdTe2. This study has shown that mineral type, electrolyte type and concentration all have an impact on the mechanisms that result in the adsorption of SIBX on PGMs.

Aug 24, 2022

By DOOLITTLE E. M.

(Canal Zone Meeting, November, 1910.) The following notes are contributed, not with the idea of offering a complete history of the development of this very important process as applied to the Leadville district, but with the hope that the practice, as it was carried out in the Bi-Metallic Smelter, may still be of interest to others. The Bi-Metallic Smelter, at Leadville, Colo., was the first to make a commercial success of the process described in the following pages, which consisted essentially of smelting raw silver- and copper-bearing sulphide ores in blast-furnaces to form a matte, which was generally re-smelted with siliceous ores for a second high-grade matte. Robert Sticht, in his excellent monograph on the subject,1 has outlined briefly the plant belonging to this company. He says, in effect: The Boulder, Mont., enterprise set the example for others with whom the patentee (w. L. Austin) had been negotiating, and the old La Plata lead-smelter at Leadville, Colo., was fashioned into a crude, temporary experimental plant for the Bi-Metallic Company, and the feasibility of the process demonstrated by a trial run. Subsequently, the plant was considerably improved, and, being supplied with very favorable ores, continued to run without interruption from August, 1892, to June, 1893. In September, 1893, smelting was resumed in a completely remodeled establishment, some $200,000 having been expended upon the new work. Thus, aside from the Montana experiments, which, under the direction of W. L. Austin, began as early as- 1885 2 at Toston, and continued with indifferent success for six or seven years, the Bi-Metallic plant at Leadville may be said to have * Formerly Superintendent, Bi-Metallic Smelting Co. + Formerly Chief Assayer and Chemist, Bi-Metallic Smelting Co. 1 Modern Copper Smelting, E. D. Peters, 7th ed., p. 415 (1895). 2 Trans., xvi., p. 259 (1887-88).

Dec 1, 1910

By E. V. Potter

"INTRODUCTION The oscillator and amplifier system described in this paper was developed specifically for driving sound generators of the type developed by H. W. St. Clair and described by him in an article 3/ published several years ago in the Review of Scientific Instruments.Nevertheless, with little or no alteration it can be used to drive any vibrating system in which the vibrating member must be driven at its resonant frequency; the only restrictions are that the driving mechanism be electrical in nature and that the vibrating member be accessible so that some type of pick-up can be coupled to it. Operation of the automatic frequency-control element in the oscillator, however, depends entirely on the operating characteristics of the vibrating member; therefore, in order to completely explain the operation of the circuit, it will be necessary to describe the construction and operation of the vibrator used with it. Only the essential features and characteristics of the vibrator will be described in this article, and the reader is referred to St. Clair's 4/ report for further details."

May 1, 1943

By Collin L. Stewart

A summary of the results of a limited subsidence monitoring program at Cyprus Amax Coal Company's Shoshone Mine No. 1 in the Hanna Basin of south central Wyoming is presented. The monitoring program was designed to meet regulatory requirements for confirmation of subsidence predictions made in the mining permit. The longwall panels were 380 ft to 600-ft wide. Mining heights varied from 11 ft to 13.5 ft. Gate road development included three-entry and two-entry head and tail gates. Overburden depth varied from 150 to 945 ft. The coal seam and overburden dip at approximately 11 degrees. The overburden is very low to low strength mudstone and carbonaceous shale with low to moderate strength, silty sandstone interbeds. Panel W/h ratios varied from subcritical to supercritical. Smax was 0.9 of the mining height. The subsidence ratio was about 0.6 for subcritical width. The draw angle on the up-dip side averaged 20 deg. The draw angle on the down-dip side averaged 12 deg.

Jan 1, 1995

A comprehensive analysisof rock structures in non-oriented (axially oriented) drillcore is now available (Laing, in press). The system embodies new concepts which better equip the geologist and engineer to deal from the outset with optimising the acquisition of structural information in drillcore, logging, interpreting, and graphically presenting the results. The few existing techniques for determining orientations of structures are augmented by a wide range of new techniques, and all are brought together into two solution types by considering the underlying Euclidean geometries. Analysis of these solution types in terms of what data are required to implement each solution and what assumptions need to be made, leads to strategies which facilitate intelligent design of different drilling programs for blind and outcropping situations. Drillcorc is variably structurally fertile, depending on the number of different structures present. This concept fosters the selective logging only of the more fertile core. Drillholes are also variably fertile, depending on their orientational relationship to the structures in the host rocks. Structural parameters are either vectorial or non-vectorial. Vectorial structures parameters comprise normal structural orientations plus polar vectors like vergence, younging, shear sense and so on. They can be determined by one of two solution types: external solutions, which use an external reference structure to fix the drillcore and thus permit orientation of all structures within that core, and internal solutions, which use orientational data from a selected structure at three or more different drillhole orientation to determine the unique orientation of that structure, without reference to any external structure.

Jan 1, 1990

By J. A. Barr, R. B. Burt, I. S. Tillotson

THE pumping of solids in water suspension is an important part of many metallurgical and mining operations. In most cases, it is still in the rule of thumb category for which no universal formula has been developed, and much research is needed. Because of the limited and incomplete data available, this article may be classed as an experience paper, which is presented with the hope that some contribution will be made toward the development of the so-called universal formula. This formula, if and when developed, may be evolved from several factors, many of which are not now available for general application. The designing engineer is interested in obtaining accurate forecasts on: 1—the minimum velocities needed to prevent choke-ups in the pipeline, which in turn dictates pipe sizes, 2—power required for pumping, 3—pump selection. The basic factors for a given problem will include: 1—weight per unit of time of solids to be handled, 2—specific gravity of solids, for calculation of volume, friction and power, 3—screen analysis of solids with the colloidal acting, i.e., the slime fraction, a very important factor, 4— shape of particle or some means of determining a friction constant, 5—effects of percentage of solids, 6—development of a viscosity factor to be used in the overall calculations, 7—calculation of the lower limits of pipeline velocities permissible, 8—calculation of total head, pump horsepower, and 9—setting up of pump specifications. In certain limited cases horsepower and total heads and minimum velocities may be computed and a suitable pump selected from basic data, but in many cases, as in mining of Florida pebble phosphate, experience rather than a hydraulic formula still should be used as a basis of selection. Pumping Florida Pebble Matrix Pumping at the Noralyn mine of International Minerals and Chemical Corp. will be used as an example. Other areas will vary as to the characteristics of the matrix, especially the slime content. A typical screen analysis of this matrix is: +14 mesh, pebble size,* 2.1 pct; —14 +35 mesh, 11.4 pct; -35 +I50 mesh, 60.5 pct; -150 mesh, 25.0; total, 100 pct; moisture in bank, 20.0 pct; weight per cu ft in bank, 120 lb. The —150 mesh fraction may increase to as much as 35 pct in adjacent areas. When thoroughly elutriated, the matrix has a relatively slow settling rate, which is an important factor in permitting lower pipeline velocities without choke-ups. Exact data is not available to evaluate settling rates. For a factor of 100 a suspension of clean building sand in water is suggested. When pumping long distances, a quick settling matrix allows the coarser solids to settle out along the bottom of the pipeline, causing drag, turbulence, and increased friction. With a slow settling matrix as at Noralyn, turbulence acts to keep the solids in suspension at a lower friction head, regardless of the pumping distance. When the pebble content of the matrix, i.e., the + 14 mesh fraction, is in excess of 10 pct of the total solids, trouble may be expected from settling out even in normal pumping distances. To prevent choke-ups and maintain tonnage, an additional pump must be added in the long runs, where one pump would otherwise be satisfactory. A typical pulp handled is: total volume, 7800 gpm; water, 4500; solids pumped per hr, 4200 lb; sp gr pulp, 1.4; percent solids in pulp, 46.; pipe size, 16-in. ID; pulp velocity, 12.85 fps; probable critical velocity, 10 fps, as below this minimum velocity choke-ups would be numerous. In calculating friction heads the Armco handbook is used where a roughness factor based on 15-year-old pipe is set up. Because the pipe used in pumping matrix is smooth and polished because of the scouring action of the phosphate and its silica content, the head losses in the Armco table for water are practically the same as in pumping the Noralyn matrix through smooth pipe, plus the fact that conditions vary widely over short periods, making accurate determinations difficult to obtain. New pumps and pump changes are being tested continuously and a wealth of data built up. This has resulted in a substantial improvement and lower relative costs in pumping matrix. The Florida phosphate industry is constantly seeking to offset higher wage and material costs with improved technique. Until a few years ago a 12-in. discharge pump was commonly used, with heads as low as 80 ft. Sizes have gradually increased and heads more than doubled. For example, the following pump was placed under test at the Noralyn mine: make, Georgia Iron Works; size, suction 16 in., discharge 14 in.; impeller, 39-in. diam; motor, 600 hp, slip ring; full load speed, 514 rpm. The results were increased head, higher capacity than the older design, with fewer pumps in the line from mine to washer.

Jan 1, 1953

By R. B. Burt, J. A. Barr, I. S. Tillotson

THE pumping of solids in water suspension is an important part of many metallurgical and mining operations. In most cases, it is still in the rule of thumb category for which no universal formula has been developed, and much research is needed. Because of the limited and incomplete data available, this article may be classed as an experience paper, which is presented with the hope that some contribution will be made toward the development of the so-called universal formula. This formula, if and when developed, may be evolved from several factors, many of which are not now available for general application. The designing engineer is interested in obtaining accurate forecasts on: 1—the minimum velocities needed to prevent choke-ups in the pipeline, which in turn dictates pipe sizes, 2—power required for pumping, 3—pump selection. The basic factors for a given problem will include: 1—weight per unit of time of solids to be handled, 2—specific gravity of solids, for calculation of volume, friction and power, 3—screen analysis of solids with the colloidal acting, i.e., the slime fraction, a very important factor, 4— shape of particle or some means of determining a friction constant, 5—effects of percentage of solids, 6—development of a viscosity factor to be used in the overall calculations, 7—calculation of the lower limits of pipeline velocities permissible, 8—calculation of total head, pump horsepower, and 9—setting up of pump specifications. In certain limited cases horsepower and total heads and minimum velocities may be computed and a suitable pump selected from basic data, but in many cases, as in mining of Florida pebble phosphate, experience rather than a hydraulic formula still should be used as a basis of selection. Pumping Florida Pebble Matrix Pumping at the Noralyn mine of International Minerals and Chemical Corp. will be used as an example. Other areas will vary as to the characteristics of the matrix, especially the slime content. A typical screen analysis of this matrix is: +14 mesh, pebble size,* 2.1 pct; —14 +35 mesh, 11.4 pct; -35 +I50 mesh, 60.5 pct; -150 mesh, 25.0; total, 100 pct; moisture in bank, 20.0 pct; weight per cu ft in bank, 120 lb. The —150 mesh fraction may increase to as much as 35 pct in adjacent areas. When thoroughly elutriated, the matrix has a relatively slow settling rate, which is an important factor in permitting lower pipeline velocities without choke-ups. Exact data is not available to evaluate settling rates. For a factor of 100 a suspension of clean building sand in water is suggested. When pumping long distances, a quick settling matrix allows the coarser solids to settle out along the bottom of the pipeline, causing drag, turbulence, and increased friction. With a slow settling matrix as at Noralyn, turbulence acts to keep the solids in suspension at a lower friction head, regardless of the pumping distance. When the pebble content of the matrix, i.e., the + 14 mesh fraction, is in excess of 10 pct of the total solids, trouble may be expected from settling out even in normal pumping distances. To prevent choke-ups and maintain tonnage, an additional pump must be added in the long runs, where one pump would otherwise be satisfactory. A typical pulp handled is: total volume, 7800 gpm; water, 4500; solids pumped per hr, 4200 lb; sp gr pulp, 1.4; percent solids in pulp, 46.; pipe size, 16-in. ID; pulp velocity, 12.85 fps; probable critical velocity, 10 fps, as below this minimum velocity choke-ups would be numerous. In calculating friction heads the Armco handbook is used where a roughness factor based on 15-year-old pipe is set up. Because the pipe used in pumping matrix is smooth and polished because of the scouring action of the phosphate and its silica content, the head losses in the Armco table for water are practically the same as in pumping the Noralyn matrix through smooth pipe, plus the fact that conditions vary widely over short periods, making accurate determinations difficult to obtain. New pumps and pump changes are being tested continuously and a wealth of data built up. This has resulted in a substantial improvement and lower relative costs in pumping matrix. The Florida phosphate industry is constantly seeking to offset higher wage and material costs with improved technique. Until a few years ago a 12-in. discharge pump was commonly used, with heads as low as 80 ft. Sizes have gradually increased and heads more than doubled. For example, the following pump was placed under test at the Noralyn mine: make, Georgia Iron Works; size, suction 16 in., discharge 14 in.; impeller, 39-in. diam; motor, 600 hp, slip ring; full load speed, 514 rpm. The results were increased head, higher capacity than the older design, with fewer pumps in the line from mine to washer.

Jan 1, 1953

By J. A. Barr, R. B. Burt, I. S. Tillotson

THE pumping of solids in water suspension is an important part of many metallurgical and mining operations. In most cases, it is still in the rule of thumb category for which no universal formula has been developed, and much research is needed. Because of the limited and incomplete data available, this article may be classed as an experience paper, which is presented with the hope that some contribution will be made toward the development of the so-called universal formula. This formula, if and when developed, may be evolved from several factors, many of which are not now available for general application. The designing engineer is interested in obtaining accurate forecasts on: 1—the minimum velocities needed to prevent choke-ups in the pipeline, which in turn dictates pipe sizes, 2—power required for pumping, 3—pump selection. The basic factors for a given problem will include: 1—weight per unit of time of solids to be handled, 2—specific gravity of solids, for calculation of volume, friction and power, 3—screen analysis of solids with the colloidal acting, i.e., the slime fraction, a very important factor, 4— shape of particle or some means of determining a friction constant, 5—effects of percentage of solids, 6—development of a viscosity factor to be used in the overall calculations, 7—calculation of the lower limits of pipeline velocities permissible, 8—calculation of total head, pump horsepower, and 9—setting up of pump specifications. In certain limited cases horsepower and total heads and minimum velocities may be computed and a suitable pump selected from basic data, but in many cases, as in mining of Florida pebble phosphate, experience rather than a hydraulic formula still should be used as a basis of selection. Pumping Florida Pebble Matrix Pumping at the Noralyn mine of International Minerals and Chemical Corp. will be used as an example. Other areas will vary as to the characteristics of the matrix, especially the slime content. A typical screen analysis of this matrix is: +14 mesh, pebble size,* 2.1 pct; —14 +35 mesh, 11.4 pct; -35 +I50 mesh, 60.5 pct; -150 mesh, 25.0; total, 100 pct; moisture in bank, 20.0 pct; weight per cu ft in bank, 120 lb. The —150 mesh fraction may increase to as much as 35 pct in adjacent areas. When thoroughly elutriated, the matrix has a relatively slow settling rate, which is an important factor in permitting lower pipeline velocities without choke-ups. Exact data is not available to evaluate settling rates. For a factor of 100 a suspension of clean building sand in water is suggested. When pumping long * Pebble is a commercial designation for the coarser fraction of finished phosphate from a washer, usually +14 mesh. distances, a quick settling matrix allows the coarser solids to settle out along the bottom of the pipeline, causing drag, turbulence, and increased friction. With a slow settling matrix as at Noralyn, turbulence acts to keep the solids in suspension at a lower friction head, regardless of the pumping distance. When the pebble content of the matrix, i.e., the + 14 mesh fraction, is in excess of 10 pct of the total solids, trouble may be expected from settling out even in normal pumping distances. To prevent choke-ups and maintain tonnage, an additional pump must be added in the long runs, where one pump would otherwise be satisfactory. A typical pulp handled is: total volume, 7800 gpm; water, 4500; solids pumped per hr, 4200 lb; sp gr pulp, 1.4; percent solids in pulp, 46.; pipe size, 16-in. ID; pulp velocity, 12.85 fps; probable critical velocity, 10 fps, as below this minimum velocity choke-ups would be numerous. In calculating friction heads the Armco handbook is used where a roughness factor based on 15-year-old pipe is set up. Because the pipe used in pumping matrix is smooth and polished because of the scouring action of the phosphate and its silica content, the head losses in the Armco table for water are practically the same as in pumping the Noralyn matrix through smooth pipe, plus the fact that conditions vary widely over short periods, making accurate determinations difficult to obtain. New pumps and pump changes are being tested continuously and a wealth of data built up. This has resulted in a substantial improvement and lower relative costs in pumping matrix. The Florida phosphate industry is constantly seeking to offset higher wage and material costs with improved technique. Until a few years ago a 12-in. discharge pump was commonly used, with heads as low as 80 ft. Sizes have gradually increased and heads more than doubled. For example, the following pump was placed under test at the Noralyn mine: make, Georgia Iron Works; size, suction 16 in., discharge 14 in.; impeller, 39-in. diam; motor, 600 hp, slip ring; full load speed, 514 rpm. The results were increased head, higher capacity than the older design, with fewer pumps in the line from mine to washer.

Jan 1, 1953

By R. B. Burt, J. A. Barr, I. S. Tillotson

THE pumping of solids in water suspension is an important part of many metallurgical and mining operations. In most cases, it is still in the rule of thumb category for which no universal formula has been developed, and much research is needed. Because of the limited and incomplete data available, this article may be classed as an experience paper, which is presented with the hope that some contribution will be made toward the development of the so-called universal formula. This formula, if and when developed, may be evolved from several factors, many of which are not now available for general application. The designing engineer is interested in obtaining accurate forecasts on: 1—the minimum velocities needed to prevent choke-ups in the pipeline, which in turn dictates pipe sizes, 2—power required for pumping, 3—pump selection. The basic factors for a given problem will include: 1—weight per unit of time of solids to be handled, 2—specific gravity of solids, for calculation of volume, friction and power, 3—screen analysis of solids with the colloidal acting, i.e., the slime fraction, a very important factor, 4— shape of particle or some means of determining a friction constant, 5—effects of percentage of solids, 6—development of a viscosity factor to be used in the overall calculations, 7—calculation of the lower limits of pipeline velocities permissible, 8—calculation of total head, pump horsepower, and 9—setting up of pump specifications. In certain limited cases horsepower and total heads and minimum velocities may be computed and a suitable pump selected from basic data, but in many cases, as in mining of Florida pebble phosphate, experience rather than a hydraulic formula still should be used as a basis of selection. Pumping Florida Pebble Matrix Pumping at the Noralyn mine of International Minerals and Chemical Corp. will be used as an example. Other areas will vary as to the characteristics of the matrix, especially the slime content. A typical screen analysis of this matrix is: +14 mesh, pebble size,* 2.1 pct; —14 +35 mesh, 11.4 pct; -35 +I50 mesh, 60.5 pct; -150 mesh, 25.0; total, 100 pct; moisture in bank, 20.0 pct; weight per cu ft in bank, 120 lb. The —150 mesh fraction may increase to as much as 35 pct in adjacent areas. When thoroughly elutriated, the matrix has a relatively slow settling rate, which is an important factor in permitting lower pipeline velocities without choke-ups. Exact data is not available to evaluate settling rates. For a factor of 100 a suspension of clean building sand in water is suggested. When pumping long * Pebble is a commercial designation for the coarser fraction of finished phosphate from a washer, usually +14 mesh. distances, a quick settling matrix allows the coarser solids to settle out along the bottom of the pipeline, causing drag, turbulence, and increased friction. With a slow settling matrix as at Noralyn, turbulence acts to keep the solids in suspension at a lower friction head, regardless of the pumping distance. When the pebble content of the matrix, i.e., the + 14 mesh fraction, is in excess of 10 pct of the total solids, trouble may be expected from settling out even in normal pumping distances. To prevent choke-ups and maintain tonnage, an additional pump must be added in the long runs, where one pump would otherwise be satisfactory. A typical pulp handled is: total volume, 7800 gpm; water, 4500; solids pumped per hr, 4200 lb; sp gr pulp, 1.4; percent solids in pulp, 46.; pipe size, 16-in. ID; pulp velocity, 12.85 fps; probable critical velocity, 10 fps, as below this minimum velocity choke-ups would be numerous. In calculating friction heads the Armco handbook is used where a roughness factor based on 15-year-old pipe is set up. Because the pipe used in pumping matrix is smooth and polished because of the scouring action of the phosphate and its silica content, the head losses in the Armco table for water are practically the same as in pumping the Noralyn matrix through smooth pipe, plus the fact that conditions vary widely over short periods, making accurate determinations difficult to obtain. New pumps and pump changes are being tested continuously and a wealth of data built up. This has resulted in a substantial improvement and lower relative costs in pumping matrix. The Florida phosphate industry is constantly seeking to offset higher wage and material costs with improved technique. Until a few years ago a 12-in. discharge pump was commonly used, with heads as low as 80 ft. Sizes have gradually increased and heads more than doubled. For example, the following pump was placed under test at the Noralyn mine: make, Georgia Iron Works; size, suction 16 in., discharge 14 in.; impeller, 39-in. diam; motor, 600 hp, slip ring; full load speed, 514 rpm. The results were increased head, higher capacity than the older design, with fewer pumps in the line from mine to washer.

Jan 1, 1953

By Ghiani M, Currelli L, Fuganti A

the results of an experimental study aimed at beneficiating a complex ore containing bastnaesite and other rare-earth minerals, with associated barite and fluospar are illustrated. Owing to its minero-petrographic, physico-mechanical and structural characteristics, the crude ore is not amenable to classic concentration methods, such as flotation, magnetic and gravity separation. Therefore the technical feasibility of selective disintegration followed by size classification has been studied, whereby bastnaesite and the other rare-earth minerals can be concentrated into the finest size fractions. Leaching and subsequent extraction of rare-earth metals by liquid-liquid separation represents the final stage of beneficiation.

Jan 1, 1993