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By James A. Barr

Prospecting methods used in Tennessee have gradually improved with the years, as required by depletion of the easily accessible and shallow deposits and the universal trend toward mechanization, and as necessitated by exploring deeper beds, often occurring under limestone and flinty overburden. In the early days it was a very simple matter to dig pits by hand, using a plentiful supply of local farm labor to expose relatively shallow deposits of "brown rock" under shallow clayey overburden that would stand up without timbering. Visual inspection of the exposed phosphate and expert judgment of the "grade" analysis, aided by a "biting" test to reveal presence of unwanted silica, furnished most of the information required. All this might be helped by a few samples sent to the local chemist† who supplemented his income by judicious trading or tanning a few bear skins. The extra curricula activities did not affect the accuracy of the analysis which hold up even under present day standards. Some shot and core drilling was done in Hickman County, mostly for the limestone-like blue Phosphate deposits. The next step was the use of a 4-in. posthole auger, hand operated as described by Guenther, followed by a completely mechanized rig, as described by Pickard. Both these methods are practically adapted to the prospecting of the relatively soft brown rock deposits at moderate depths of clay overburden. For prospecting in areas of deeper overburden, such as are often found in Hickman County, up to 150 or even 200-ft depths, a modified core-drilling method is described by Guenther. Johnston describes a special diamond-drilling technique, developed by TVA, to penetrate flint horizons, which was adopted by the International Minerals in chemical corporation to prospect in Hickman County where deposits had previously been prospected at considerable expense and with difficulty, by small, temporary, hand-dug shafts.

Jan 1, 1948

By Joseph J. Yancik

In Moscow, the delegation received a briefing on the Soviet coal industry from First Deputy Minister Vladimir Fedanov. A similar briefing was given to us on the Donets coal basin by Deputy Minister S. Saratikyanz of the Ukrainian Coal Ministry. Lengthy technical discussions were held with the mines staff and research personnel at the institutes we visited. In addition, we had detailed discussions with key staff members of two combinats; Donetskugol and Tulaugol. In all these meetings, principal topics were matters of safety related to hazards associated with face mechanization, coal transport, methane gas control measures, gas outbursts, coal and rock outbursts, fire fighting and control, explosion suppression and control measures, and other related hazard factors. There was also much discussion on miner training, miners' attitudes toward safety and accident prevention practices, and preparation and enforcement of safety rules and regulations. It would be helpful to briefly review Soviet coal production statistics for comparison purposes with the U.S., and for the purpose of referencing some of the delegation findings mentioned in this report. For an excellent, comprehensive picture of Soviet coal production and other related fuel statistics, the reader is referred to Strishkov's, et d. report.1 Strishkov's estimates agree with the numbers given us by Coal Ministry officials except in clean coal tonnage. The figures of 604 million mt of clean coal out of a total production of 655 tons raw coal in 1972 is much higher than Strishkov's estimate of 375 million mt clean coal.

Jan 7, 1974

SUGGESTIONS that existing schools give instruction bearing on the mineral industry, or that schools for that purpose should be established in the United States, began to be made early, and it would require too much space to catalogue them all. Some of the more important may be mentioned to indicate their general character. In the "advertisement to such parents as have now (or expect to have) children prepared to be educated in the College of New York," which appeared in the New York Mercury of June 3, 1754, Samuel Johnson, the first president of King's College, the predecessor of Columbia, said that it was the "design of this college to instruct and perfect the youth," among other things, "in the arts of Numbering and Measuring of Surveying, and Navigation and Geography. . . . and in the Air, Water and Earth around us, and the various kinds of Meteors, Stones, Mines and Minerals, Plants and Animals; and in the knowledge of all Nature in the Heavens above us, and of everything useful for the Comfort, Convenience and the Elegance of Life . . . " Though the concept that natural science should be used to enlarge the bounds of human life was thus implicit at Columbia from the , very beginning (John Stevens graduated from it in 1768, James Renwick in 1807, Horatio Allen in 1833, and A. W. Craven in 1899), it was only during the period of Renwick's professorship of Natural and Experimental Philosophy and Chemistry (1830- 1853) that much attention was given to applied science.* Among the Austin papers, published by the American Historical Association,~ there is a draft in Stephen F. Austin's handwriting of a proposed memorial from the legislature of , Missouri to Congress, not only urging "the propriety and utility * See chapter 4 for early interest in this subject in Philadelphia.

Jan 1, 1941

By P. A. Beck, W. D. Manly

In a recent note Sully and Head1 showed that the Cr-Fe sigma phase is isomorplious with the Cr-Co gamma phase, and that the lattice constants are also nearly identical. In a preliminary investigation of the ternary Cr-Co-Fe system at 800°C at this laboratory the above findings were confirmed, and it was found by microscopic techniques, using various etching reagents, that the two binary phases form an urinterrupted series of solid solutions with each other. These solid solutions occupy a straight narrow band which cuts across the 800°C isothermal section of the ternary system, connecting the two binary phases. A detailed investigation of the Cr-Co-Ni ternary system at 1200°C disclosed that here, too, the Cr-Co gamma phase extends deep into the ternary system in the form of a long narrow lip. The fact that this sigma type lattice is sustained even when well over half of the Co atoms in it are replaced by Ni atoms, with relatively little change in the Cr content, clearly indicates that Ni itself has a certain tendency to form the sigma phase with chromium. This tendency is hidden in the binary Cr-Ni alloys, where the sigma phase is not known to occur, but it becomes operative in the presence of a suficient amount of Co. The interpretation of these facts in terms of electron concentrations is rendered difficult by the uncertainty of our present knowledge of the valency electron structure of the transition elements in their alloys. However, Sully and Heal's results and the present work suggest that intermetallic phases with signla type lattice may occur more frequently in these little investigated alloys than heretofore suspected. In particular, it is expected that a similar phase may exist in the V-Co and perhaps in the V-Ni system, in analogy to the known sigma type phase in the V-Fe system, and that all these sigma type phases may form extensive solid solutions with one another.

Jan 1, 1950

By James A. Barr

Prospecting methods used in Tennessee have gradually improved with the years, as required by depletion of the easily accessible and shallow deposits and the universal trend toward mechanization, and as necessitated by exploring deeper beds, often occurring under limestone and flinty overburden. In the early days it was a very simple matter to dig pits by hand, using a plentiful supply of local farm labor to expose relatively shallow deposits of "brown rock" under shallow clayey overburden that would stand up without timbering. Visual inspection of the exposed phosphate and expert judgment of the "grade" analysis, aided by a "biting" test to reveal presence of unwanted silica, furnished most of the information required. All this might be helped by a few samples sent to the local chemist† who supplemented his income by judicious trading or tanning a few bear skins. The extra curricula activities did not affect the accuracy of the analysis which hold up even under present day standards. Some shot and core drilling was done in Hickman County, mostly for the limestone-like blue Phosphate deposits. The next step was the use of a 4-in. posthole auger, hand operated as described by Guenther, followed by a completely mechanized rig, as described by Pickard. Both these methods are practically adapted to the prospecting of the relatively soft brown rock deposits at moderate depths of clay overburden. For prospecting in areas of deeper overburden, such as are often found in Hickman County, up to 150 or even 200-ft depths, a modified core-drilling method is described by Guenther. Johnston describes a special diamond-drilling technique, developed by TVA, to penetrate flint horizons, which was adopted by the International Minerals in chemical corporation to prospect in Hickman County where deposits had previously been prospected at considerable expense and with difficulty, by small, temporary, hand-dug shafts.

Jan 1, 1948

By P. Somasundaran, R. D. Kulkarni

Reagentizing at elevated temperature, reported in the past as beneficial for the flotation of hematite using oleate, is studied here as a function of collector concentration, solution pH and ionic strength at various levels of conditioning temperature. The study revealed strong interactions between variables; particularly, the effect of conditioning temperature was found to strongly depend on the ionic strength of the solution. Thus, while an increase of conditioning temperature at lower ionic strengths or that of ionic strength at lower temperatures resulted in an increase of both flotation and grade, an increase of the former at higher ionic strength or that of the latter at higher temperatures caused a significant decrease in both responses. These observations have been explained in terms of the increased chemisorption of oleate at elevated temperatures and the temperature effect of ionic-strength on the salting out of the oleate from the bulk solution. The above effects which were first observed during Hallimond cell flotation tests were subsequently tested with Denver cell using low-grade iron ore. The results obtained using the two test procedures were in agreement with each other. The implications of these effects and interactions for process control of optimum flotation performance must be noted since variation in the levels of the above parameters are likely under plant conditions.

Jan 1, 1978

The Library of .the above-named Societies is open from 9 A.M. to 9 P.M. on all week-days; except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may he what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 6, 1913

By B. G. Bunting, D. L. Abata, J. Robb, J. H. Johnson

Toxic gases produced by the detonation of six explosives were measured in an underground hardrock metal mine during mining operations. The explosives included two semi-gelatin dynamites, three slurry explosives, and an ammonium nitrate, fuel-oil/ammonia dynamite combination. Explosives were detonated at the face of a drift and toxic gases produced by the detonation were trapped at the end of the drift by a bulkhead located a short distance away from the face. Toxic gas concentrations were then measured with direct readout instruments and together with the containment volume, the toxic gas volumes per mass of explosive were calculated. Toxic gas measurements were found in the following ranges (ft3/1bm): NO, 0.0100-0.035; N02, 0.003-0.019; CO, 0.08-0.30; SO2, 0.00-0.05; and CO2, 0.7-1.8. Results showed that toxic gas production (ft3/lbm) correlated with the densities (kg/m3) and energy densities (kJ/kg) of the explosives tested.

Jan 1, 1983

By A. K. Sinha

The annual production and productivity of underground coal mines in recent years declined from 334 Mt (368 million st) and 14.5 t (16 st) per man per shift in 1969 to approximately 254 Mt (280 million st) and less than 8 t (9 st) per man per shift in 1977. Productivity is still hovering at about 7.25 t (8 st) per man per shift. According to US Bureau of Mines, the estimated US coal reserve is about 396 Gt (437 billion st), 68.65% of which is obtainable by underground mining methods. Approximately 153 Gt (169 billion st), or about 85.2% of the high Btu premium coking coal of the eastern US, would need to be extracted by underground mining methods. It is thus apparent that under- ground mining will continue to play a major role in total US coal production, which is expected to rapidly increase to about 1.1 Gt (1.2 billion st) by 1985, with about 606 Mt (668 million st) being contributed by underground mines. Production Potential of Continuous Mining The production potential of a continuous mining section depends primarily on the producing ability of the miner, transporting ability of the face haulage, and the matching of the two systems. The producing ability of the continuous miner depends on its actual cutting ability and the time available for cutting coal. The performance of 10 continuous miners operating in coal seams of various thicknesses were monitored in Pennsylvania and West Virginia, using continuous electrical power analyzers and time studies. The recordings on current and power strip charts yielded an accurate analysis of the cutting, trimming, and idle times of the machines on a full shift basis. Continuous miners of various models and sizes from 112-298 kW (150-400 hp) were monitored. Based on actual cutting time, the average cutting ability of the machines, as shown in [Fig. 1], ranged from

Jan 1, 1983

Present indications are that the Fourth National Exposition of Chemical Industries, to be held in Grand Central Palace, New York, Sept. 23 to 28, will be the greatest exhibition of its kind ever held. Preparations are well under way and the advisory committee is working hard to make, every department of the affair a success. Men prominent in the chemical and allied industries will speak on subjects vital to present conditions and needs. Dr. C. H. Herty, and Dr. G. W. Thompson, President of the American Institute of Chemical Engineers, are to make opening addresses. F. J. Tone, President of the American Electrochemical Society; Dr. W. H. Nichols, President of the American Chemical Society, and several others, are expected to make addresses also. Prof. Joseph W. Richards will speak on : ?Ferro-alloys of silicon, tungsten, uranium, vanadium, molybdenum, and titanium." Theodore Swann, President of the Southern Manganese Corporation will speak on "Ferro-manganese." The program for the exposition is in active preparation. There will be a series of symposiums on the "Development of Chemical Industries in the United States, notably since July, 1914." Among other topics for consideration is that of potash development; C. A. Higgins, of the Hercules Powder Company, will speak of the operations of that company in the recovery of potash from kelp; Linn Bradley, of the Research Corporation, on its recovery from cement dust, and other sources, by electrical precipitation. Other symposiums will be devoted to chemical engineering, acids, industrial organic chemistry, the ceramic industries, and the metal industries. Among the speakers are: A. Hough.-" Chemical Engineering in Explosives: TNT; TNA; Picric Acid; and Nitrobenzol." E. J. Pranke.-" Development of Nitric Acid Manufacture." S. P. Sadtler.-"Development of Industrial Organic Chemistry." Geo. H. Tomlinson.-" Wood as a Source of Ethyl Alcohol." C. A. Higgins.-"Kelp as a, Source of Organic Solvents." Alcan Hirsch.-" Pyrophoric Alloys."

Jan 9, 1918

By Mack H. Shumate

1 Raw coal from Truax-Traer Coal Co.'s Burning Star Slope mine, Jackson County, Ill., is brought to the surface by the new 42-in. slope belt haulage conveyor at the rate of 850 tph. The loading system shown above employs four storage tracks, two tail tracks for loading, and four 25-hp hoists, operating in pairs, and coupled to two dolly cars to move the trains of cars through the tipple. The system has a capacity for loading 1800 tph. One operator is needed to load on each of two shifts. A third man working for a few hours on night shift sets up for the morning cycle. Railroad crews bring in empties placing them in the storage yard, twenty cars to the track. Trains of empties are pulled through to the tail track and loaded on the return; hoists at opposite ends pull the trains in each direction. [ ] 2 Pairs of hoist drums are interconnected electric- ally by a Trench lay cable buried between the tracks. When one hoist operates moving the cars, the tail hoist idles with brake released. The operator, situated in the tipple over the cars, views the storage yard at the end of the first shift (left). When returning loaded cars to yard, four or five cars are held on the dolly to couple the next string of empties. Empties are ready for loading on the tail track (right). Differing from a gravity system in which empty and load tracks are on a slight grade, this system is designed for 80 railroad cars for a two-shift operation and one rail service per day.

Jan 6, 1962

By Alan R. Grant

The Cascade Range of Washington can be considered metallogenetically to be primarily a copper province. Structural and chemical data compiled from examination of numerous copper occurrences in the Cascades indicate a marked parallel of physical conditions for sulfide deposition. In probable order of significance, the environmental criteria are as follows: 1) adjacent or subjacent, postregional metamorphism high-level intrusive activity, most commonly in the time range from 15 million years to 30 million years; 2) transverse northeast trending structural belts which obliquely cut the northwest regional trend of the range; 3) potassium-silica wall rock alteration; most important of the alteration suite of silicates are orthoclase secondary biotite and quartz; 4) the intersection of northwest trending and northeast trending structures. The varying geologic environments in the Washington Cascades present a complex setting for the sulfide deposits. The North Cascades are comprised of predominantly pre-Tertiary metamorphic rocks invaded by Tertiary calcalkaline intrustive rocks. The Central Cascades, lying south of the North Cascades, exhibit a younger, higher level geologic environment comprised of predominantly early to middle Tertiary volcanic rocks and subordinate sedimentary rocks which are intruded by Tertiary calc-alkaline igneous rocks. Although the Tertiary Cascade intrusions are dominantly quartz dioritic, copper mineralization is commonly found in rocks of quartz monzonite to granite composition. These acid rocks appear to be the product of late stage magmatic K alteration of the original quartz diorites. Sulfide concentrations are considered to be in part dependent on the degree of K-silicate activity and the intensity of transverse structural deformation.

Jan 1, 1973

By S. F. Shaw

THE principles involved in lifting oil in wells flowing naturally are identical with those underlying the flowing of wells by means of the air-gas lift, and information of a dependable nature obtained in the study of the air-lift can be applied to wells with natural flow. A well flowing naturally is one in which the lifting is done by means of the gas-lift, for which the gas is supplied entirely by the formation from which the oil is derived. In air-gas lift operations, there is insufficient gas supplied by the formation to lift the oil to the surface in an efficient manner, therefore additional gas for this purpose must be furnished from an outside source. There may, at times, be conditions obtaining in natural flowing wells different from those in wells flowed by gas-lift, but these differences do not at all conflict with the main principles of gas-lift work. One such condition is met with in wells in which the gas supplied by the formation is in considerable excess of that required to lift the oil to surface; this excess may be so great as to reduce the quantity of oil that can be lifted through the particular diameter of casing or tubing that has been lowered into the well. This same condition can be brought about, however, by supplying a large excess of gas from an outside source to an artificial gas-lift well, and a study of the effects obtained from injecting a large excess into the well can be applied directly to handling wells flowing naturally which have a large excess of gas supplied by the underground reservoir.

Jan 1, 1929

The Library of the above-named Societies is open from 9 A.M. to 10 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more. promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 12, 1914

By S. Oglesby, A. L. Thomas

Until recently, probably the best means of sampling airborne dusts has been the impinger method. Dust-laden air is drawn into a sampling tube, and the particulate matters separated from the air and collected in the liquid in the impinger. A sample of the suspension is prepared on a slide and counted through a projection microscope. This method is simple and reliable, but it does suffer drawbacks. Since the collected particles must be counted visually, results of the dust count are not immediately available at the time the sample is taken. This seriously impedes studying the effectiveness of dust inhibitors, such as water sprays, or making adjustments in equipment. Greatest disadvantage of all, however, is the tedious task of counting particles in the sample. With the growing desirability of taking more samples, the effort involved in making these counts is a real factor in the cost of dust control. Finally, it is generally recognized that impinger dust counts can be related to health hazard only for specific kinds of dust and under similar conditions. This is because the rather complex mechanism of dust damage depends so much on size distribution of the dust. Counts determined by impinger samples cover a limited size range that does not necessarily corre-

Jan 1, 1960

By Walter Miller

Developments in oil refining were so varied during 1938 that a refiner had to be alert or be left behind. The long-talked-of conversion of oil refining into a true chemical industry using petroleum as a raw material was hastened, particularly in the realm of motor-fuel manufacture, by the increased understanding and use of catalytic processes. The petroleum refiner's vocabulary has been extended to include alkylation, cyclization, aromatization, and isomerization. There are other devel: opments of a similar nature, but these are now considered commercially feasible under proper conditions. New Equipment Less expensive equipment and processes encouraged new construction and replacement. Estimates of money spent in the United States on building new plants and remodeling existing installations during 1938 place the sum at not less than $200,000,000, a noteworthy amount in a year marked by a business recession. The commercial application of small-scale catalytic polymerization of refinery gases made one of the latest advances available to the smaller operators, who usually are faced with unit installation and production costs higher than the large refinery enjoys. Competition was thereby fostered. Outstanding in this respect was the construction of two or more polymerization plants in small refineries at extremely low installation costs, with amortization measured in months instead of years. Houdry Processes Bursting like a bombshell late in the year was the disclosure of the extent of the development of the Houdry processes of catalytic cracking, viscosity breaking, gasoline treatment, desulphurization, and polymerization, said to be applicable to almost any raw petroleum stock and yielding gasoline of exceptionally high octane number. This process is claimed to be particularly adapted to once-through cracking of aliphatic hydrocarbons, and when combined with any of the conventional thermal

Jan 1, 1939

By Rossiter W. Raymond

THE most important event in the history of mining in the United States was the discovery of gold in California, which led to the rapid development, not only of a new industry, but of a new empire. The settlement of the Pacific slope was making but slow progress under the inducements of a scanty commerce in furs and hides. The liberal grants offered by the government to agricultural pioneers in Oregon had attracted to the Willamette valley and other favored points in that territory a limited population; but the government of the Mexicans in California was positively unfavorable to enterprise. It is true that gold was known to exist in the country. Rumors of it were current among the trappers, and placers had actually been worked in what is now Los Angeles County ; but the padres of the neighboring mission of San Fernando had discouraged the business as demoralizing to their flocks ; and the existence of the precious metal was not widely known; still less was its distribution north¬ward suspected. The discovery of gold, January 19th, 1848, at Sutter's saw-mill, on the south fork of the American River, afterward famous as Coloma, in Eldorado County, was the beginning of the new epoch. This discovery was made by James Wilson Marshall, a partner in the mill, who observed in the debris washed down by the tail-race a glittering fragment of a mineral unknown to him. Suspecting it to be gold, he sought for further specimens, and obtained, in the course of a few days, several ounces of it. Tests subsequently

Jan 1, 1875

By T. S. Lundy

Anand and Agarwala recently determined diffusion coefficients by the residual activity (Gruzin) method for several tracers in large-grained, high-purity aluminum. D values at any particular temperature in the range of 400" to 630°C were about four orders of magnitude lower for cd115, 1n114, sn113, and pdlm than for Ag. Corresponding values for Do and Q in the Arrhenius equation were also quite small. It was pointed out previously that unusually low diffusion coefficients within the region of a specimen near a free surface may be the major cause of such anomalous results for impurity diffusion in silver and in aluminum.44 Anand and Agarwala considered this possibility but rejected it because their penetration profiles were "homogeneous" and "yielded diffusion coefficients obeying the Arrhenius plot". Neither of these two criteria satisfactorily prove or disprove the presence of a near-surface effect. Such can be accomplished only by direct serial sectioning in which the chips ground from the specimen are assayed for tracer content. In fact, such experiments always should be done prior to use of the somewhat indirect Gruzin method where the finer details of the transport process cannot be determined. There have been several other reports of unusually low D, Do, and Q values for impurity diffusion in silver and aluminum.1"4 It is interesting to note that all of these studies made use of the Gruzin method. Also, in all cases where the same systems were examined by use of a direct serial sectioning technique, large near-surface effects were observed. One must conclude therefore that the reported anomalous diffusion parameters for cd, In114, sn113, and pd in aluminum are due to some near-surface effect, while the results for Agl10 indicate that no such effect was encountered for this system.

Jan 1, 1969

By R. P. McLaughlin

EXACT information as to performance of the gas lift from the mechanical engineering standpoint is hard to obtain. Several hundred wells are now producing in California fields by means of the gas lift, and a survey of results shows that the gas lift has increased production at these wells by approximately 60 percent. Similar or even larger figures describe results in Mid-Continent fields. Such an increase in output of oil is so satisfactory, to the average oil producer, that it may not encourage investigation looking to more efficient operation. The cost of lifting oil by compressed gas varies from 3 c. to 15 c. per bbl. of oil, depending upon the efficiency of the gas lift. A difference of 10 c. or 12 c. per bbl. of oil is immediately noticed by an oil operator and the cost in production is as real to him as is the price of his product. Therefore, the efficiency of gas-lift process deserves more consideration than it has been given in some quarters. It has been found that there is a wide variation between different operators and at different wells in the amount of gas used per barrel of oil lifted. Some of the most efficient operations show oil being lifted with only slightly over 400 cu. ft. of gas per bbl. of oil.1 On the other hand, wells are being flowed and using as high as 3000 cu. ft. per bbl. of oil. The cost of compressing gas to 300 or 400 lb. varies from 3 c. to 5 c. per 1000 cu. ft. of free gas. This figure has been obtained from a number of sources and as a matter of fact is the basis of actual business transactions involving gas compression. The cost of lifting oil with compressed gas is thus determined.

Jan 12, 1926

By Arturo M. Morales

INTRODUCTION Manganese carbonates are nodulized by Cia. Mineral Autlan, located in Ongongo in the state of Hidalgo in Mexico. This kiln is fed minus 15 mm material at the rate of 1870 tpd. About 920 tpd is nodulized into a commercial product having a size range of 15 mm to 12 mm. The kiln also produces about 320 tpd of minus 12 mm fines and 40 tpd of chimney dust. Currently, the minus 12 mm fines are being recirculated to the kiln and the chimney dust is not being utilized. It has been found that there exists a market for manganese to be used as feed to the ferromanganese and silicomanganese furnaces. However, a coarse, lumpy feed can only be used in these furnaces. Accordingly, it has been proposed to screen the fines at 6 mm and agglomerate the minus 6 mm fraction along with the chimney dust and suitable binders. This paper presents the results of a feasibility study and test work aimed at producing an acceptable agglomerated product from the kiln fines for use in the ferromanganese and silicomanganese furnaces. Since the agglomerated product will have to be handled and loaded into trucks in the kiln area and transported over long distances, a minimum strength of 200 N is expected to be necessary. They should also have enough initial strength to be stockpiled and result in a minimum of breakage. A third important requirement is that the agglomerates should be resistant to disintegration during combustion. The recirculating fines were to be agglomerated in their original state, if possible, that is, without grinding. This eliminated the possibility of pelletizing as an agglomeration method. Based on a few laboratory trials, the briquetting method seemed most attractive, and a test program was initiated to explore the briquetting process.

Jan 1, 1977