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By Edwin T. Myskowski, Alfred H. Hesse

THE development by the U. S. Bureau of Mines of a process for purifying manganese by electrolysis has stimulated interest in manganese alloys. While recent publications have shown some alloys of manganese and copper to possess rather unusual properties, none have included information on tensile properties, which have an important bearing on the usefulness of the alloys. Manganese-copper alloys can be heat-treated, since the single phases that exist at high temperatures may be retained by quenching. According to Persson,1 when quenched alloys containing from about 30 to nearly 100 per cent manganese are reheated, alpha manganese is precipitated (Fig. I). Calculations based on Persson's X-ray data indicate that this decomposition is accompanied by a change in volume of as much as 5 per cent. The reason that this large volume change has not been noted probably is the slow rate at which equilibrium is reached by these alloys. In an investigation on hardening by cold-work and heat-treatment, Dean and Anderson' found that quenched alloys increase in hardness with manganese content and that high-manganese alloys harden very slowly with cold-work, while high-copper alloys harden much more rapidly. Heat-treatment has little effect on manganese-copper alloys containing less than 40 per cent Mn, and affects those alloys containing more than 40 per cent in accordance with their manganese content and heat-treating temperature. Dean and Anderson4 also found that cold-work increased electrical resistance of alloys containing from 50 to 80 per cent Mn, and that heat-treatment of alloys containing from 40 to 96 per cent Mn altered the electrical resistance considerably. Dean, Anderson and Potter5 have shown that the high vibration damping capacity that characterizes manganese-copper alloys containing 40 to 90 per cent Mn is affected by cold-work and heat-treatments. Highest vibration damping capacity at low stresses was obtained by heating for 2 hr. at 450°C. (842°F.) after quenching from solution temperatures. Preparation of Alloys.-The alloys for these tests were melted in a 17-lb. basic-lined high-frequency induction furnace using electrolytic manganese, grade A ingot copper and a 70-30 Cu-Mn master alloy (69.80 per cent Cu, 0.12 Fe, 0.04 Si, 0.006 S, 0.07 C, balance Mn). The manganese was heated slowly to expel excess dissolved gases and melted before the addition of copper. No fluxes or covers were used. The melts were cast in tapered iron molds and the ingots were reduced 90 per cent when forged to ½ -in. rounds. These rods were given 2-hr. solution treatments at temperatures that depended upon the composition (Table I). Tensile Tests.-The tensile specimens, 0.313-in. diameter (1.25-in. gauge length), which were enclosed in evacuated Pyrex

Jan 1, 1942

By Orville R. Lyons, A. C. Richardson

DURING the past few years there has been a growing demand by coal operators for detailed information about the performance characteristics of the various dryers now being manufactured, preferably in such a form that the information could be used to determine the type of dryer best suited to a particular drying problem. A few operators have been desirous of going even further, because they are of the opinion that present-day dryers are not properly designed and that fundamental studies of dryer design should be undertaken. This growing demand for a method of dryer evaluation and the indicated need for fundamental research resulted in the sponsorship by Bituminous Coal Research, Inc. of a project at Battelle Memorial Institute to investigate the thermal drying of coal. In investigating this problem, the most feasible method of attack appeared to be a survey of active operations to determine the present status of the thermal drying of coal. Data were obtained, usually by actual plant tests with the cooperation of the various preparation engineers and their staffs, for Q screen-type dryers, 8 rotary- type dryers, 3 continuous-pallet-type dryers, 2 flash-type dryers, I tray-type dryer, and I cascade-type dryer. The testing program provided: (I) data for 24 coal- drying operations, (2) information about dried, (3) information about the previous treatment that the coal had received, and (4) information about operating costs. The data obtained through the dryer survey and relationships determined from the data make it evident that all of the types of dryers included in the survey can be operated with the same degree of effectiveness if each type of dryer is used to dry the sizes of coal for which it is best suited. It should be noted that it is usually undesirable and often impossible to dry different sizes of coal in one type of dryer. By use of the data in the report, any prospective dryer user, having determined the surface moisture percentage and screen- size analysis of the coal to be dried, the tons of water to be removed per hour, and the final surface moisture percentage desired, should be able to determine with a fair degree of accuracy: (I) the difficulty of the drying problem, (2) the approximate cost of drying, (3) the required dryer inlet gas temperature and volume and exhaust gas temperature and volume, (4) the type of dryer to use, and (5) the size of dryer required. The method of testing the dryers and determining the difficulty of drying can be used by operators already having dryers to check the performance of their particular dryer and determine whether they are operating effectively. Considerably more information was obtained from the survey of thermal drying than was anticipated when the survey was first considered. However, a great deal of work still remains to be done in the field

Jan 1, 1948

By R. W. Gurry

In the course of a series of measurements of the rate of diffusion of carbon in austenite at about 960°C. (1760°F.) and III0°C. (2030°F.), it became necessary to determine carbon concentration when austenite is saturated with graphite, because of indications that the hitherto accepted value of the solubility of graphite in this temperature range is too low. Specimens of carbonyl iron were saturated at temperature in a hydrogen-toluene atmosphere which was in equilibrium with graphite. The carbon conteDt of the steel was measured either by combustion or by the loss of weight after substantially complete decarburization in an atmosphere of hydrogen saturated at room temperature with water vapor. The absence of carbide or graphite as a phase at temperature was demonstrated by microscopic examination of saturated specimens that had been drastically quenched, The mean result of concordant ments-—taeats-is-^that gamma iron saturated with respect to graphite contains 1.39 per cent carbon at 957°C .(i755°F.) and 1.89 per cent at III0°C. (2030°F.). These two values, plotted along with what appears from the literature to be the best value (0.69 per cent) at the iron-graphite eutec-toid temperature (738°C. or I360°F.), yield a curve that is almost linear, and which, continued upward through a short interval, leads to a limiting solubility of 1.98 per cent at the iron-graphite eutectic temperature II35°C. (2075°F.) instead of the commonly accepted value of about 1.7 per cent. Experimental Procedure The samples of carbonyl iron, with the exception of those for microscopic examination, were cylinders 3.8 cm. long, 0.475 cm. in diameter. They were placed in a graphite holder and suspended in a vertical furnace, the temperature of which was controlled precisely by means of the resistance of the platinum winding.' In the empty furnace the range of temperature over a distance of 4 cm. at the heat center was 9°C. (I6°F.) but at a given location the temperature remained within +o.5°C. (o.9°F.); it was measured by inserting a platinum-rhodium couple calibrated at the melting point of palladium, 1555°C. Since the presence of the sample probably improved the uniformity of temperature, it was decided to consider the average temperature of the sample to be 3°C. lower than the maximum measured in the empty furnace with the same setting of the controller. Data were obtained in the vicinity of two temperatures, 960°C. (I760°F.) and III0°C. (2030°F.). The samples for microscopic examination, 2.2 cm. long, 0.475 cm. in diameter, were suspended individually on pure iron wire; for these no temperature correction was applied. The carburizing gas passed into the furnace was dry, oxygen-free hydrogen saturated at room temperature with toluene; this quickly produced on the

Jan 1, 1942

By R. W. Gurry

In the course of a series of measurements of the rate of diffusion of carbon in austenite at about 960°C. (1760°F.) and III0°C. (2030°F.), it became necessary to determine carbon concentration when austenite is saturated with graphite, because of indications that the hitherto accepted value of the solubility of graphite in this temperature range is too low. Specimens of carbonyl iron were saturated at temperature in a hydrogen-toluene atmosphere which was in equilibrium with graphite. The carbon conteDt of the steel was measured either by combustion or by the loss of weight after substantially complete decarburization in an atmosphere of hydrogen saturated at room temperature with water vapor. The absence of carbide or graphite as a phase at temperature was demonstrated by microscopic examination of saturated specimens that had been drastically quenched, The mean result of concordant ments-—taeats-is-^that gamma iron saturated with respect to graphite contains 1.39 per cent carbon at 957°C .(i755°F.) and 1.89 per cent at III0°C. (2030°F.). These two values, plotted along with what appears from the literature to be the best value (0.69 per cent) at the iron-graphite eutec-toid temperature (738°C. or I360°F.), yield a curve that is almost linear, and which, continued upward through a short interval, leads to a limiting solubility of 1.98 per cent at the iron-graphite eutectic temperature II35°C. (2075°F.) instead of the commonly accepted value of about 1.7 per cent. Experimental Procedure The samples of carbonyl iron, with the exception of those for microscopic examination, were cylinders 3.8 cm. long, 0.475 cm. in diameter. They were placed in a graphite holder and suspended in a vertical furnace, the temperature of which was controlled precisely by means of the resistance of the platinum winding.' In the empty furnace the range of temperature over a distance of 4 cm. at the heat center was 9°C. (I6°F.) but at a given location the temperature remained within +o.5°C. (o.9°F.); it was measured by inserting a platinum-rhodium couple calibrated at the melting point of palladium, 1555°C. Since the presence of the sample probably improved the uniformity of temperature, it was decided to consider the average temperature of the sample to be 3°C. lower than the maximum measured in the empty furnace with the same setting of the controller. Data were obtained in the vicinity of two temperatures, 960°C. (I760°F.) and III0°C. (2030°F.). The samples for microscopic examination, 2.2 cm. long, 0.475 cm. in diameter, were suspended individually on pure iron wire; for these no temperature correction was applied. The carburizing gas passed into the furnace was dry, oxygen-free hydrogen saturated at room temperature with toluene; this quickly produced on the

Jan 1, 1942

By D. F. VanDine

The phases of a typical exploration program for sand and gravel resources include: (1) collection and assessment of existing information; (2) air photo interpretation and remote sensing; (3) ground investigation and mapping; (4) sampling and testing; and (5) data storage, retrieval, analysis and presentation. Depending on the purpose, time frame and funding available for the study, these phases, and the various techniques used within each phase, will vary. Once a sand and gravel deposit has been located, defined in size and quality, and found to be suitable for a given purpose, it can then be classified as a granular resource.

Jan 1, 1984

By C. Chapman, M. G. Reading, M. P. Amsden

Ecstall Mining Limited, a subsidiary of Texas Gulf Sulphur Company, operates the Kidd Creek Mine, a 10000 tons per day base metal producer, near Timmins, Ontario. Two different types of ore are mined and milled: copper-zinc and silver-lead-zinc. At the highly automated Ecstall concentrator the ores are processed by selective flotation in three individual circuits. One of the most important metallurgical tools for process control is a sample system incorporating continuous on-stream X-ray analysis. Recently this system was automated further by the addition of computer control of reagents for two copper-zinc flotation circuits. The computer programs, utilizing optimum seeking methods and smelter contract terms, have increased copper recovery by 1.1 per cent, zinc recovery by 1.4 per cent, and have reduced reagent costs by 16 per cent. Although not expected, copper and zinc concentrate grades were improved slightly as well.

Jan 1, 2014

By HUBERT O. De

IN December, 1936, several drilling tests were made at the Hubert O. De Beck feldspar mine at Green Mountain, N. C., to determine the most efficient type of hammier-drill bit and drilling method for use at this particular property. This mine is well recognized as having the hardest rock in the Burnsville - Spruce Pine feldspar district and drilling costs always have been high. Local structural deformation has greatly distorted and warped the normal crystalline structure of the feldspar so the rock is much tougher than usual. In studying drilling methods and bit types, available literature was re¬viewed but little specific data could be found on the direct comparison of four-point and six-point drill bits so the following results may be of some interest.

Jan 1, 1937

By K. S. E. Forssberg, J. A. Jirestig

Laboratory investigations on the possibility of using magnetic separation for the recovery of sulfide minerals have been reported. A survey of several sulfide ores and flotation concentrates indicated that, in most cases, magnetic separation is not a suitable primary beneficiation method. However, encouraging results have been obtained in concentrate purification. At the Boliden complex sulfide ore concentrator in Garpenberg, Sweden, an Allis-SALA Mark III carousel High Gradient Magnetic Separator (HGMS) is used with a small flotation circuit to recover sphalerite lost to the galena concentrate during lead flotation. After four years of refining the HGMS process, there has been an increase in zinc recovery and an enhancement in the quality of the lead concentrate.

Jan 1, 1994

By J. B. Gayle

The rate of oxidation of coals with nitric acid has been used by earlier investigators4 5 6/ for determining fusain and for studying petrographic composition. These workers accumulated considerable evidence indicating that, for coals ranging from lignite to low-volatile in rank, the method gives values for fusain that agree satisfactorily with those obtained by optical methods. One group5/even concluded that, when discrepancies are noted between results obtained by chemical and microscopic methods, the results based on the oxidation reaction are probably the more reliable. Unfortunately, after concluding that the method was valid, most of these workers apparently lost interest. As a result, no attempt to exploit or apply the method to problems of utilization has been reported. Recent studies of the influence of inert petrographic constituents on the properties of cokes made from various coals7/ have indicated a need for additional means of characterizing coals and blends used for carbonization.

Jan 1, 1960

By Michael A. Trevits

The National Institute for Occupational Safety and Health (NIOSH) in partnership with Strata Products tested the sealing capability of Ventstop®? as part of an ongoing mine fire control and suppression research program. Ventstop®? is a multi-purpose, inflatable device that is produced by Minvent Solutions and is available world wide for use in the metal and nonmetal mining industry. Ventstop®? is also used in the Australian coal industry as a temporary ventilation control device. The device can be quickly deployed, is reusable and can be placed in horizontal and vertical mine voids to control dust, fumes and smoke. Deployment, multi-day inflation and air leakage tests were conducted at the NIOSH Lake Lynn Laboratory to determine the capability and limitations of Ventstop®? in a simulated coal mine setting. During the tests, Ventstop®? was also subjected to low level forces of a nearby methane gas ignition. It is thought that Ventstop®? could be used by the US coal mining industry to temporarily close an underground mine area in response to a fire or spontaneous combustion heating event, to temporarily redirect mine ventilation during longwall equipment moves or during stopping construction. This paper describes this inflatable temporary mine sealing technology and presents the results of the NIOSH tests.

Jan 1, 2009

By C. J. Newman

The new Kennecott Utah Copper smelter, started in 1995, was designed to be the cleanest smelter environmentally in the world. The plant is operating at production rates above the original design capacity. Copper concentrate is smelted in an Outokumpu flash smelting furnace. Matte is granulated and processed using Kennecott-Outokumpu flash converting. Copper anodes are processed in a modernized copper refinery using the Kidd Process while anode slimes are processed for precious metals recovery using a unique hydro-metallurgical process. To allow the production of high quality cathode, using modem smelting and converting technology to minimize emissions, impurity control had to be carefully addressed. All process bleed streams from the smelter and refinery are treated in a hydro-metallurgical plant to fix impurities in a stable form, allow for the rejection of impurities as required and recover valuable metals. Special technology was developed for the copper refinery to ensure production of high quality cathode from anodes containing high levels of impurities. The smelter routinely achieves a sulfur capture in excess of 99.9% which is equal to less than 2 kg of SO2 per tonne of copper produced. This paper describes the design of the smelter and refinery and includes recent production and emission data and modifications carried out to allow operation at above the original design rates. It emphasizes the unique features required to achieve environmental and quality goals and compares environmental performance data to that published on other smelting operations. The processing of intermediate streams, the management of recycled materials and the impurity control strategy will be covered in detail.

Jan 1, 1999

By Louis Frost

"1N 1951, the Dominion Steel and Coal Corporation, as part of a programme of modernization in their coal mining operations at Sydney Mines and Glace Bay, Nova Scotia, undertook the development of two large cross-measure tunnels, which were to be used for the purpose of raising the coal from the underground workings by conveyor belts direct to wash plants located on the surface.These tunnels were to reach from the surface to central loading points underground located at a depth of 600 and 900 feet, respectively. They were to be driven on a pitching gradient of 11 degrees to the horizontal, and they were to reach a length of 3,600 feet in the Sydney Mines area and 10,000 feet in the Glace Bay area.The longer tunnel, 19 feet in diameter, was driven a distance of 1,500 feet and, for domestic reasons, bas not yet been •completed. The other tunnel, in the Sydney Mines area, 18 feet in diameter, is steel supported and concreted throughout its entire length. This tunnel has been completed and will be in operation at an early date.The development of this particutar tunnel posed an additional problem, as the rock through which it had to pass was considered to be water-bearing. In the sinking of Princess Colliery shafts in 1866, a great deal of water had been encountered, and it had been necessary, while sinking, to line the shaft with cast-iron tubbing through the water-bearing strata. The shaft had to be lined for a depth of 300 feet at the upper end. It was anticipated that we would meet with difficulty in driving the tunnel through this strata."

Jan 1, 1955

By Sadtler, C. B.

IT is generally assumed that in most metals and alloys a given tensile stress produces a given deformation irrespective of the length of time during which the stress is applied. This assumption is justified in most of the important engineering applications of metallic materials; however, in the case of some metals and alloys used or tested at temperatures over or slightly under that at which recrystallization can occur the assumption is not warranted.1 This paper deals with the variations of deformation produced by a constant tensile stress acting for varied lengths of time in the special case of thin aluminum alloy sheet of the duralumin type, which had been subjected to different thermal and mechanical treatments. The material investigated was in the form of a sheet approximately 0.002 in. thick, which had been cold-rolled from a thickness of 0.020 in. It has been found that at a sufficiently high constant tension such material deforms continuously with the elapse of time and that the rate at which this deformation occurs is greatly influenced by the previous thermal and mechanical treatments.

Jan 1, 1927

By G. A. Colligan, G. L. F. Powell

A new experimental technique has been developed to study nucleation behavior in eutectic alloys. It is somewhat similar to that applied by Sundquist and Mondolfo1 but with the advantages that: 1) bulk samples are undercooled instead of small droplets thus allowing the thermal behavior to be monitored by a thermocouple immersed in the sample, and 2) nucleation behavior is investigated in the same sample on either side of the eutectic composition by adding additional component to the sample under controlled conditions which preclude the addition of nu-cleation contaminants. Sundquist and Mondolfo carried out ]nucleation ex-periments on a large number of eutectic alloy sys-tems and concluded that nonreciprocal nucleation operated. If one phase a was a good nucleant for the other phase 0, then B was a poor nucleant for a. This was determined experinlentally by comparing the nucleation temperatures of 100 to 300 u diameter droplets of hypereutectic and hypoeutectic composition cooled from above the liquidus and from a temperature between the liquidus and the eutectic temperature. Primary phase a was concluded to be an efficient nucleant for the other phase B, if the following experimental result was obtained. Referring to Fig. 1, the temperature TI at which a drop of hypereutectic alloy of composition B froze when cooled from above the B liquidus was noted. This was the nucleation temperature for B in the absence of a. A drop of hypoeutectic alloy of composition A was then frozen from temperature T2 between the a liquidus and the eutectic temperature. The temperature T3 at which the eutectic nucleated in the presence of the primary or proeutec-tic a was noted. If this temperature T3 was higher than the temperature TI at which the B nucleated in a hypereutectic alloy, it was concluded that the primary a had nucleated the 6. This temperature T3, representing a certain undercooling below the equilibrium eutectic temperature Te , was designated ?TB by a> the undercooling below T, for nucleation of 13 by a. If there was no substantial difference in nucleation temperature between the hypereutectic drop cooled from above the /3 liquidus and the hypo-eutectic drop cooled from a temperature between the a liquidus and the eutectic temperature, it was considered that the a nucleated B at an undercooling equal to or greater than that at which P nucleated from a hypereutectic alloy. Sundquist and Mondolfo1 found that faceted primary crystals were good nucle-ants for metals that grow as orthogonal dendrites when present as the primary phase. Jackson2 has questioned Sundquist and Mondolfo's technique and proposed that in Sundquist and Mon-dolfo's samples, such as composition A, primary a retained B in reentrant grooves at their surfaces when heated to a temperature above the eutectic but below the a liquidus. This objection was suggested by experiments with organic eutectics where reten-

Jan 1, 1970

Dear Member: The Proceedings for the Institute for the past year are enclosed. We hope you will read them, for there are some good ideas expressed, and the papers are far above the average. The job of publishing the Proceedings has always worried the Secretary. The Secretary, being at the same time the Treasurer, has to pay the bills, and this time he enlisted the co-operation of some of our friends. You will find this co-operation shown in the ads in the proceedings. Read the ads just as carefully, even more so, than you do the text. They carry messages from our friends. Don't forget the winter meeting in Denver, the last of February, the 26, 27 and 28. Another good paper to be read then will be that of A. L. Jones on the subject of "Power Problems of the Coal Mine." In the meantime you can do two things for the Secretary. Let the few who haven't paid their dues remit quickly so we can get our books closed. Also, when you know of a changed address of any of the Institute members, drop the Secretary a line. so he can keep the mailing list straight Very truly yours, THE ROCKY MOUNTAIN COAL MINING INSTITUTE By [ ] Sec?y-Treas. BS AHH

Jan 1, 1922

By William F. Boericke

THE Christy Creek clay mine of the General Refractories Co., in the Olive Hill District, ranks with the most important producers in the north-eastern Kentucky fire clay field, both from production of high-grade flint clay, as well as unusual extent and thickness of deposit. The property is but one of a number controlled by the General Refractories Co. in this district, but is given first consideration among them by the operating staff. Its total area is over 5000 acres, owned in fee or by lease of clay mining rights, and although mining operations have been in progress for over five years, scarcely one per cent of the ground has been worked as yet. The mine is near the southwestern end of the clay field, which extends in a belt 12 miles wide and 55 miles long, in a southwestern direction from Kenova, W. Va., which, as the name indicates, is at the junction of Kentucky, Ohio, and West Virginia. Olive Hill, where there is one of the l1Ulin plants of the General Refractories Co., and to which the clay from the mine is shipped, is about 26 miles distant from the mine. Connection is made with the Chesapeake & Ohio R. R. by a spur line . 8 miles in length, owned and operated by the company.

Jan 1, 1929

By H. W. McCue, Henry Rogatz

Oil.—In the Texas Panhandle, 502 oil wells were drilled during the year 1940, with a total daily initial production of 139,187 bb1.—that is, 137 more oil wells drilled than in the previous year, with an increase in total daily initial production of 8219 bbl. The total daily potential of the field on Dec. 31, 1940, as determined by the Texas Railroad Commission, was 1,375,502 bbl., an increase of 30,825 bbl. over the previous year. On Dec. 31,1940, a daily allowable of 85,050 bbl., which was a decrease of 35 per cent over 1939, was assigned to the field to be produced from 4788 wells. The total amount of oil produced for the year was 26,788,590 bbl., making a cumulative total of 378,960,728 bbl. during the past 19 years. No new oil-producing acreage was discovered. Gas.—During the year, 92 gas wells were drilled, having a combined open flow of 2,402,900.000 CU. ft.; that is, 6 more than the number of wells drilled in 1939, with an increase in the open flow of 204,900,000 cu. ft. per day. The gas production for the year was 670,435,112,000 CU. ft., and the total gas removed from thc ground during

Jan 1, 1941

By Henry Rogatz, H. W. McCue

Oil.—In the Texas Panhandle, 502 oil wells were drilled during the year 1940, with a total daily initial production of 139,187 bb1.—that is, 137 more oil wells drilled than in the previous year, with an increase in total daily initial production of 8219 bbl. The total daily potential of the field on Dec. 31, 1940, as determined by the Texas Railroad Commission, was 1,375,502 bbl., an increase of 30,825 bbl. over the previous year. On Dec. 31,1940, a daily allowable of 85,050 bbl., which was a decrease of 35 per cent over 1939, was assigned to the field to be produced from 4788 wells. The total amount of oil produced for the year was 26,788,590 bbl., making a cumulative total of 378,960,728 bbl. during the past 19 years. No new oil-producing acreage was discovered. Gas.—During the year, 92 gas wells were drilled, having a combined open flow of 2,402,900.000 CU. ft.; that is, 6 more than the number of wells drilled in 1939, with an increase in the open flow of 204,900,000 cu. ft. per day. The gas production for the year was 670,435,112,000 CU. ft., and the total gas removed from thc ground during

Jan 1, 1941

By Henry N. McCarl

The New England States form the most northeastern portion of the continental United States and include Connecticut, Rhode island, Massachusetts, Vermont, New Hampshire, and Maine. These states have an aggregate population of over 10.5 million people, and an average annual population rate increase of about 1.3%. A great deal of new construction is required each year to meet the increasing demand for new homes, roads, offices, factories, and warehouses. Yet, prices of construction materials such as blocks and concrete are generally higher in New England than in other well populated areas of the United States. This is an indication of local demand being somewhat greater than supply, an atmosphere conducive to new developments in the production of construction materials. One such field of development is the rapidly growing Lightweight Aggregate Industry. Recent construction in Boston has used a great deal of lightweight aggregate. New structures using lightweight aggregate in lightweight concrete include the following: M.I.T.'s 20-story Earth Science Center and 17-story Married Students Housing Project Prudential Life Insurance Center, West End Redevelopment Project at Charles River Park, Hotel Americana, and the British-owned 33-story office building at 50 Pearl Street.

Jan 1, 1964

Ventilation 'is currently used in mines to sustain human life, prevent explosions, and provide a more healthful work place. Future automated-mining systems could use ventilation techniques quite. different from today's practices. The Bureau of Mines is anticipating various methodologies for ventilating the automated mining systems which are now beginning to emerge in the mining industry. This paper examines the special ventilation requirements for automated mining systems. Topics include requirements for automated systems, current studies with blowup ventilation tubing, and ventilation of two types of highwall -ripper type mining machines.

Jan 1, 1990