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Mr. O. F. Lewis opened the meeting at 9:00 a.m. lie announced that Stan Shuhart, had the following announcement. to make: Stan. Shubart: George Delamater of Fort, Lauderdale, Florida scads greetings to his friends here at the meeting. O. F. Lewis: Thank yon, Stan. This morning we will start our meeting by turning it over to a very distinguished gentleman. I'm sure all of you know him. He started his work career many, many years ago, but lie doesn't look nearly this old, and his energy belies this. From 1.910 to 1916 he was a chemist with the American Smelting & Refining Co. at. Garfield, Utah. From 16 to '17 he was a broker with J. A. Hogle Company at Salt Lake. From 1917 to 1948 he was a metallurgist, ore buyer, assistant manager and later general manager of the Utah department. ASRC at Salt Lake City; and also president of the Garfield Chemical Co. Since 1951 to the present. time he has been President and General Manager of the Independent Coal & Coke Co. and Vice President of the Western Rock Bit Co. He has held many, many honorary positions; former Chairman of the Board of Regents of the University of Utah, former President of the Salt Lake Winter Sports Association, Past President. of the Community Chest there, and is presently a Director of National Coal Association, a Director of the First Security Bank of Salt Lake City, Utah, and also a Director of the Hotel Utah.

Jan 1, 1965

By Sam Andrews

Mr. President, Officers and Members of the Rocky Mountain Coal Mining Institute: This is my first attempt to prepare and read a paper before your association. The Rocky Mountain Coal Mining Institute, I understand, was formed for the purpose of increasing knowledge relating to coal mining in all its various branches by study, research and discussion. In writing my paper, I have tried to be as practical as I can, at the same time, present my arguments so that they can be easily understood. When I use the word science, I mean organized common sense. I humbly ask my hearers to be a little patient, while I read my paper, and be "to its faults a little blind, and to its virtues a trifle kind". Western Europe is said to be the cradle of the coal mining industry. We are told that the Ancient Britons were acquainted with the use of coal long before the Romans invaded and conquered their country. The Romans were never too proud to learn from the outer barbarians, and possibly acquired the precious secret from them: We are told that it was not until the 13th century, that the coal mining industry, assumed any noticeable importance in Britain, and on the Continent. In the year 1259 Henry the 3rd granted a charter to the freemen of New Castle on Tyne, allowing them to mine coal. For a long time it was used in the arts and manufactures only, wood continuing to be the common domestic fuel. As has been the case with almost every great benefit, the introduction of coal as a fuel was stoutly resisted at first, and we find its use prohibited in the city of London in the reign of Edward II, by Royal proclamation ; which was soon discovered to be injurious and foolish, and consequently withdrawn. It is interesting perhaps, to know how this Royal proclamation was brought about. A lady of the Royal household was riding in her coach one day through a village in which coal was burned as a fuel, and she suffered such a cough by inhaling the coal smoke that she decided to call a council of suffragetts, who ultimately decided that the burning of coal was injurious to their health and complexion. They drafted out a petition and presented it to the king, who speedily issued the order that no coal was to be burned in the city of London. The penalty for disobeying this order was death by hanging. We are informed of one poor man who continued to burn a lump of' coal on his fire in winter time; he was arrested, sent to prison and condemned to death; the judge in passing the sentence solemnly stating that if he was not allowed to get a fire that was hot enough in this world, he felt that he surely would be allowed one in the next.

Jan 1, 1921

President Robert Wilson opened the meeting at 9:00 a.m. He introduced William A. Bear, General Manager Bear Coal Company, Inc., Somerset, Colorado, who presided over the session. George Nugent, Peter Kiewit Sons' Company, Sheridan, Wyoming, presented a most interesting film "Montana Mine Reclamation." His biography follows: George Nugent first entered the coal business in 1943 when he developed Peter Kiewit Sons' Co.'s first coal mine-Big Horn Coal Company at Sheridan, Wyoming. Since that time he managed an expansion program for P.K.S. in mining that resulted in the development of two other producing mines - Rosebud Coal Sales Company at Hanna, Wyoming and Decker Coal Company at Decker, Montana, in which Pacific Power and Light is a partner. Applications are now pending for a third mine. Black Butte, a joint venture of P.K.S. and Rocky Mountain Energy Company, near Point of Rocks, Wyoming. Nugent is a Past President of the Wyoming Chapter, Association of General Con- tractors, Wyoming Mining Association and Rocky Mountain Coal Mining Institute. He was President of Big Horn Coal Company and Rosebud Coal Sales Company as well as Manager of the Mining Division of Peter Kiewit Sons' Co. and Decker Coal Company when he retired Jan. 1, 1975.

Jan 1, 1976

By D. C. McClure

MR. McCLURE: Mr. Chairman, you sprang a surprise on me; I really came over here for a good time. Gentlemen, I am not at all qualified to pose as an expert on pulverized fuel; I have merely been making some rather interesting observations, and unfortunately at the present time, a great deal of substantial data, the technical data, I don't happen to have with me; it is still in the process of being calculated, but I will be very glad to tell you some of the observations as I have made them, and in as truthful and complete a way as I can. The question of how we would handle fuel became a very pressing subject in this new Valmont electric plant, which is now under progress. We have studied the methods of burning fuel for a number of years on different types of stokers at the existing plants in Denver; we are burning it with a natural draft chain grate and with underfeed and with forced draft chain grates, and I am very frank to confess at the present time that I have no answer as far as stokers are concerned for a better solution of the problem of burning lignite. In other words, I could not tell you that this or that is a better type of stoker to use for that coal. However, to boil the thing down, after considerable trials, the underfed stoker was chosen as the one most adaptable for the utilizing of lignite fuel if stokers are to be used. In other words, the chain grate was put aside. I might say in support of the chain grate, the prime reason for which that type of stoker was condemned, as far as lignite goes, is the initial investment charge and the large maintenance which is involved.

Jan 1, 1923

By H. Petersen

If a coal mine producing two hundred thousand (200,000) tons of coal per year could effect a 2 per cent decrease in the percentage of slack there would be an additional 4,000 tons of prepared coal produced. Most operators will say that these prepared sizes of coal are worth about $3.00 more per ton to them than the slack or in other words an additional $12,000.00 pier year profit could be made by a decrease of 2 per cent in slack. A large tipple with all the finest modern equipment of shaker screens, conveyors, box car loaders, etc., can only produce a grade of coal dependent upon the coal delivered by the mine car at the top of the tipple. In the mine, coal-cutting machines have been doing their part for many years toward decreasing the percentage of slack. There is therefore, only one phase of production left where real effective work can be done, that is, intelligent and constant supervision of preparatory work and shooting. The quality of coal is really entirely dependent upon the kind of coal produced at the face in the mine. Our problem is therefore, at that place. The writer is thoroughly convinced that with the proper placing of holes the use of correct amount of a suitable explosive, thoroughly tamped, with the bug dust entirely removed from the mining, a decrease in slack can be effected. We will take up this problem under five headings. First-The proper placing of bore holes. Second-The proper amount of permissible powder. Third-The proper loading and stemming of the shot.-Cushing shooting. Fourth-The necessity of removing the bug dust from the mining. Fifth - The - standardization of rounds. First-The Proper Placing of Bore Holes. The most important thing and the real secret of successful blasting of coal is the proper placing of the bore hole. This results in the correct balancing of the shot and the securing of the maximum efficiency of the explo¬sive. If you are operating a mine with a 6-foot coal seam, you most likely are using a 6-foot cutter bar on the coal cutting machines. You should use three holes to properly bring down the coal. (1) A center shot in the middle of the room drilled flat, or rather parallel to the mining-the heights of this hole will depend upon the top parting. If the coal is frozen to the roof, it will be necessary to have the hole as close to the roof as possible. If there is a free parting, the hole may be placed lower but not over twelve inches from the roof. (2)

Jan 1, 1925

MR. C. M. GODDARD: Mr. Poli invented this little safety switch box. This junction box he has does improve the appearance mentioned in the underground junction boxes used in the foreign countries, where this thing is compulsory. There was some arrangement whereby the attachment could not be made with the switch in. The switch has got to be out of place before they can put the terminals into this box, which avoids all possibilities of short-circuits, except where protected on the inside of this box. In mines that are not gaseous, this is not so essential, but he has invented a very small junction box which probably. could be built for six or eight or ten dollars; if those things are necessary, for the handling of mining machines and their apparatus, takes current off the transmission line, and he has something that would meet that requirement, and I think when it is looked into it will meet the approval of the Bureau of Mines. He had this little box yesterday, and some of the members had looked it over and think, if they will look more favorably into it, they will find something to their advantage. PRESIDENT PRYDE: I think it is a good idea to bring in safety appliances and devices at this meeting. There were two more devices brought in here this morning; one a safety powder flask, and the other a carbide can. We have talked a great deal about permissible powder. It is going to take a little time to change over, and we would have to use the black powder cans. I will leave them in the window, if you care to investigate them.

Jan 1, 1924

[Proceedings VOL. II. PART V. CONTENTS PAGE Mine Haulage, by R. A. McAllister-----------------145 Efficiency in Shot Firing, by Robert A. Marshall -- 149 Some Facts About Coal Mining, by Sam Andrews -153 Flexoid Tubing and Its Application to Coal Mines As a Means of Temporary Ventilation, by George A. Brown -161 Longwall Coal Mining, by Thomas Collier ------ 163 Advantages of Having Such Men as Fire Bosses Under State Rather Than Corporation Jurisdiction, by R. S. Morton ---- 165 Longwall Mining, by Parley Potter -------169 DeWatering of the Rouse Mine, by D. A. Stout ---175]

Jan 1, 1921

By R. A. Marshall

Much has been written by men connected with the coal mining industry, and mining laws have been enacted for the safety of the men employed in the mines, and for the protection of property connected therewith. It seems almost impossible for anyone to select a subject that has not already been read, discussed and put into effect, especially in the coal mines of Western America. There is, however, a subject of much interest to the mining public, and to which I have given a great deal of study and consideration, and which I believe will be received by this convention, and will be given due consideration in the future in applying it to the safety of the mine,- "Efficiency in Shot Firing." Beginning with 1865, and for a period of 28 years in the state of Colorado, the annual reports of the chief inspectors show that 1159 coal miners were killed in the following manner: Five hundred eighty-two by falls of rock and coal ; 517 by gas and dust explosions; 6o by careless handling of explosives and the shooting of coal by the, individual, miner. It is my firm belief that 75 per cent of these fatal accidents might have been avoided, if a safe and proper shot firing system had been installed, at each and every mine. This may sound unreasonable, but I believe that the blasting of coal by the individual miner, and the use of black powder, squibs and fuse has, in reality, caused the death of many miners, from shock after blasting, the shooting out 'of timbers, and working in powder smoke, which fatal accidents were attributed to falls of rock or coal. These conditions led the people of Colorado, through their representatives of the General Assembly of Colorado, to enact a new coal mining law, and in 1913 this law became effective, containing twelve sections devoted to the subject of Efficiency in the System of Shot Firing. During the period 1913 to 1920, the employment of a shot firer, the use of permissible. powder, and the electric hand battery has resulted in safer mines, safer miners and safer shot firers, and I believe every coal mine in the state should employ first-class, certified shot firers, use permissible powder and fire the shots with an electric hand battery. I believe where gas generates in dangerous quantities, which is generally determined by inspection of the mine, and the daily report, the shooting in. such a mine should be done by electric battery located outside of the mine. Where permissible powder is used, I have seen the shot firer start down the mine with a belt around his waist containing one hundred caps, a safety lamp to test for gas, and an open light to ignite the fuse. Would it not be much safer for the shot firer if he used the electric hand battery? In non-gaseous mines where black powder is used, I have. seen the miners carry fuse into the mine, and shot firers have been known to partly tamp the holes, which was

Jan 1, 1921

The 77th Regular Meeting of The Rocky Mountain Coal Mining Institute convened at the Marriott's Mark Conference Center, Lionshead Village, Vail, Colorado, and was in session at 10:00 a.m. Past President, Loren V. Linville, District Sales Manager. Industrial Products Division. Uniroyal. Inc., Denver. Colorado, called the meeting to order. He introduced President, Edward F. Ziolkowski, Senior Vice President and General Manager, Energy Development Company, Hanna. Wyoming. A biographical sketch follows: Ed Ziolkowski is a 1953 graduate from the Colorado School of Mines with a degree in Engineer of Mines. His mining career began with Pickands Mathers Company in Gogibic Iron Range in Northern Wisconsin and Michigan. In 1961 he joined Texas Gulf Sulphur Company as Shaft Mining Engineer for their Cane Creek Potash Project near Moab, Utah. After serving as General Mine Foreman. Mine Superintendent and General Superintendent at Cane Creek, he was transferred in 1969 to Green River. Wyoming as Project Manager of Texas Gulf Black's Fork Trona Development. In 1971 he joined Allied Chemical Green River Works, as Resident Manager. In 1972 he joined Energy Development Company, an Iowa Public Service Company Subsidiary, as General Manager of their Coal Development. He currently is Senior Vice President and General Manager of Energy Development Company, and serves on their Board of Directors as well as the Boards of several other subsidiaries. This past April he was elected to Iowa Public Service Company's Board of Directors. Ed, his lovely wife Pat and children live in Hanna, Wyoming. He has been a member of the RMCMI since 1973. Is a staunch supporter of his community and the mining industry.

Jan 1, 1981

MR. GIBSON (continuing): In connection with the coal from this mine, I will say that it is not a very dirty coal. The vein where most of the coal comes from is about eight feet thick, and two feet from the bottom there is a small boney band about two inches thick. The breaking shot has to be placed over the, band, therefore breaking the boney into fine particles which goes off with the slack. This coal is a very good domestic coal and the slack is in great demand for various power, plants, such as sugar plants, smelters and other industries, but where this, boney is broken up and goes into the slack, it is very injurious in effect and retards the sale of the slack. Therefore the Spring Canyon Coal Company went to the expense of' building this plant, costing over $250,000, just in order to get that, two inches of boney coal out of the rest of the vein. The market in, Utah is very critical, and in order to sell coal, the product must be thoroughly clean in every way and, as Mr. Murphy says, I believe they have succeeded in making a very good commercial product. In any event the Spring Canyon Coal Company put out more coal than any other one mine during the last year, 1924, they had the largest production. I thank, you. (Applause). PRESIDENT MARKS: With the assistance of Mr. Robinson and Mr. Miller, I am sorry you could not get the pictures a little better synchronized with the story. MR. F. C. MILLER (Chief Chemist The Colorado Fuel & Iron Company, Pueblo) : We had seven slides to show eighteen different views on the screen and we did remarkably well. (Laughter.) PRESIDENT MARKS: Is there : any further discussion on this paper? MR. G. B. JONES (Mining Inspector, Victor-American Fuel Co.) : I would like to ask a question on the

Jan 1, 1926

Lloyd W. Ingles, Superintendent, Allen mine, Colorado Fuel and Iron Corporation. Stonewall, Colorado, called the meeting to order at 9:30 a.m. He introduced George C. Trevorrow, Safety Director, Bituminous Coal Operators' Association, Washington, D. C., who spoke on "Recent Developments for Improving Safety in Underground Coal Mines." (Refer to the index for the printed text of this paper.) Following Mr. Trevorrow's paper, James Westfield, U. S. Bureau of Mines, Washington, D. C., spoke briefly to the group or some of the new methods of controlling fire mentioned in Mr. Trevorrow's paper. Mr. Westfield stated that the Foam plug had been used in the Bureau's experimental mine, and was also used in New Mexico, but was not successful in putting out the lire. In a recent fire in Southwest Virginia where 18 men were lost, the foam plug was used after the fire had been burning for about 6 or 7 days. It did have a good effect, but the section had to be finally sealed off. In a fire in Pennsylvania about 2 weeks ago, the foam plug was put into action after about 9 hours. Although the section was finally sealed, managers of the mine credited the foam plug in saving the mine. Mr. Westfield stated that equipment must be at hand when fighting a fire; that time wasted in securing proper equipment may make the difference. Mr. Westfield also stated that as late as 2 months ago, it seemed that a methane monitoring device was as far as 4 or 5 years away. Now it is expected that it may be put in production within the year. Experimental models are in use in Pennsylvania and West Virginia. Mr. Westfield concluded by complimenting Mr. Trevorrow on his excellent paper.

Jan 1, 1960

T. T. READ, BUREAU OF MINES: Mr. McAuliffe has asked a very practical question. Expressed in another way, the question is: If we have decided to use rock dust to prevent coal dust from exploding, have we got to take rock, that is, solid material,, break it up and finally grind it into dust (and fine grinding is very expensive), or can we take material that is already in a pretty fine state of subdivision and thereby save the expense of pulverizing it? Most of the preceding discussion has been from the view-point of practical experience, and I should like to suggest that we have not had enough practical experience in rock dusting to be able to answer this question, from the viewpoint of experience, with the degree of definiteness that Mr. McAuliffe desires. With your permission I will discuss the matter briefly from the theoretical standpoint, because after all the theoretical considerations, insofar as we understand them correctly, will apply to every' case, whereas in coming to a decision on this matter it will be necessary to take into consideration local conditions, which will necessarily vary in every case. Considering the matter in a rather elementary way, the first point is: What makes coal dust explode? The air of this room is full of dust at the present moment, even though we do not notice it. If you were to close up the room for a week, enough dust would settle on the floor so you could write your name on it. Of course, the dust which is in the air of this room is not coal dust but even if it were coal dust and you were to bring an open light in' here we all know that the dust would not explode. The reason for that is that the dust particles are not close enough together for the flame to propagate itself from one to the next. You will probably be able to see in the demonstration in the gallery on Saturday that the coal dust explosion is practically a very rapid burning of the dust. When you light one piece of dust it burns and gives out heat and if there is another piece of dust close enough to it so that the heat from the first piece is able to bring a second piece up to the burning temperature, then the flame will propagate itself through the mixture. But, if the particles are so far apart in the air that the' heat from one particle is dissipated before it reaches an adjoining one, and is therefore not able to bring the second particle up to the burning temperature, then the flame will not propagate. To get a coal dust explosion, it is not sufficient to have coal dust suspended in the air. The coal dust particles must be close enough together in the air so that the heat from one burning particle is able to heat the adjoining particles up to the point at which they will burn. There has been some discussion of the size of dust particles that will cause an explosion to propagate, and it has been pointed out that the minus 200-mesh dust is the most dangerous, and that particles coarser than 20-mesh will not propagate an explosion. There are two reasons for that. A large particle has very much smaller surface in proportion to its weight than a small particle has. You know the old story about the Indian who when asked how he could go around in cold weather without any clothes on said that an Indian was all face. A 200-mesh particle is almost all surface and there= fore is able to burn almost instantaneously, which means that it gives out its heat almost instantaneously, whereas a large particle with less surface in proportion to its weight burns more slowly, gives out its heat more slowly, and the heat has more time to be dissipated. The second reason why coarse dust does not easily propagate a flame is because it is so hard to make it

Jan 1, 1924

The thirtieth regular meeting of the Rocky Mountain Coal Mining Institute was called to order at 11: 20 o'clock A. M., Wednesday, June 3, 1931, President G. A. Kaseman presiding: PRESIDENT KASEMAN spoke in part as follows: I have in mind to say a few words of welcome to the coal operators, but I am afraid that the words I might have said would be hardly appropriate, because I believe the coal operators are in the minority today. It demonstrates to my mind something that has been running through it for some little time. When the hard times came on a year ago, we thought we were going to get over it rather lightly. I recall at this time a year ago we thought that the depression was about at an end. The National Administration from Washington told us we had reached bottom and things were going to perk up, and for a few weeks or maybe a month or more there was a sort of optimism throughout the country. I had been East, and when I re- turned to Albuquerque I said to my friends and associates that things were getting better in the East and that they would soon be better out here and we will not have felt the hard times very much. But I have learned differently since. I have learned that hard times are no respecter of communities or corporations, or persons, or activities, and that we all suffer alike. On that account we find that our Institute is suffering just the same as other activities, whether national, state, local, social, or what- ever it may be. Our attendance is light or, that account. We all know when times are hard we have to stay at home and watch things closer than when they are good. And when they are good we feel that the machine will run of its own momentum and in this way we can get away to see what is going on in the world. When times are hard we have to stay at home and look after everything from day to day and hour to hour.

Jan 1, 1931

By Eli Follett

It is indeed gratifying to note the marked improvement in the methods used in the coal- mines today compared to the methods in earlier days. Away back in the decade of 1900 to 1910 many of the mines were conspicuous for their absence of sprinkling and humidifying systems, as a result much of the natural moisture was absorbed by the dry air current and carried out of the mine and the mine was left dry, dusty and dangerous. This dangerous condition was intensified by large accumulations of fine coal dust on the haulageways where fire flashed from poorly lubricated rollers and bullwheels-trip riders used a torch with a flame reaching to the back of their necks, and large supplies of blasting powder were kept in the mines. Accidents and disasters were very frequent as we, in our ignorance flirted with danger. Staggered by the numerous accidents, and the nature of them; men began thinking along lines of safety, they worked out schemes and after many disappointments succeeded in having, some very whole some legislation enacted covering coal mining operations only to find that much lawlessness was still being practiced by the miners whom they sought to protect; step by step these safety men forged ahead, enlisting the co-operation of a few men about the mine whom they called a safety committee, until, today, we have an ironclad mining law which all have to respect. We have sprinkling and humidifying systems, the miners electric lamp, permissible explosives and many other devices making for greater safety in the operation of our coal mines. Our mines are no longer veritable gasometers and powder storehouses, as I. knew them to be in South Wales, Britain, where I started to work in the mines. Instead, the mines of this day are healthy, well lighted and ventilated workshops and too much cannot be said in the praise of safety engineers who, fought altruistically in their efforts to bring about the wonderfully improved conditions in the coal mines of this day. While the possibility of a mine fire starting, in these days of scientific mining, is remote every one admits there still exists a possibility and to deal with a fire, should one start, most coal miners are equipped with fire extinguishers. Extinguishers of all designs conceivable are on the market, the different extinguishers are charged with different chemical substances, Some are charged with patented chemicals and others with baking soda and sulphuric acid and so on, however, many of them are equipped with about eighteen inches of rubber hose and bear the conventional "FOR FIRE-TURN UPSIDE DOWN" but nothing is said to indicate how close it may be necessary to take the extinguisher to the fire before doing the "TURN UPSIDE DOWN" act, neither is anything said as to what effect the contents may have upon the' hands, face or body of operator should he come in contact with the liquid, nor is any warning given as to the dangers in the fumes which may come from the contents of the extinguisher in contact with the fire.

Jan 1, 1922

By T. H. Butler

The two most talked of questions in the mining industry today are rock dusting and mechanical loading. The one as a matter of safety, and the other as a matter of economy, and both are of vital interest to the mining fraternity. Rock dusting and other safety methods will be dealt with by others at this meeting, so I will confine my few remarks to the matter of mechanical loading. I will not attempt to tell you what mechanical loaders are doing in the different mining fields throughout the country, or what they should do, but will endeavor to give you an outline of the work being done with mechanical loaders in No. 4 Mine of the Union Pacific Coal Company, at Hanna, Wye. In order that you may better understand and be in a position to follow me it will be necessary to cite the conditions under which we are working. and the type of loaders in use. The seam pitches from 14 to 17 degrees, and is normally 32 feet in thickness, and is overlaid with a soft sandstone roof. The panel system of working is used, planes being driven on the pitch, and rooms driven on the strike. Owing to faults being encountered planes are driven between the faults, and the. rooms on either side are in some instances 800 to 1,000 feet in depth. Rooms are advanced eight feet in height, and 32 feet in width, by hand loaders and .Toy mechanical loaders, and when driven to the boundary,, 18 feet of the remaining 24 is loaded out with Thew electric shovels, and six feet left to protect the roof. In January, 1916 the company installed a Type 1 Thew shovel, equipped with a 1 1/4-yard dipper, and in July, 1917, they installed a Type 0 Thew electric shovel, equipped with a 1-yard dipper, and in the year 1918 two additional Type 0 Thew shovels, equipped with a 1-yard dipper, were installed, making a total of four Thew shovels for this mine. The introduction of these shovels caused the employees much concern, and like all departures from the old methods of mining, met with indifference by some and open antagonism by others, so that for some time they results obtained were not satisfactory. However, by constant supervision and changes in the method of haulage the results obtained at present, while not entirely satisfactory, are much better and the production and costs are reasonably good. The Thew shovels in use are mounted on traction wheels with swivel axle and move. in all directions by their own power, and while the weight of each is approxi¬mately 20 tons, they are not as cumbersome as. one would think and are easily operated. The system used in working these shovels is to shoot the coal clown ahead of the shovels and maintain two tracks, two cars being used on each track so that shovel is loading on one track while driver is, changing cars on the other. When place is finished the shovel is run back to the first cross-cut by its own power and lowered to the next room with block and tackle, the roof coal in cross-cut being shot down to a height of 16 feet to allow passage of the boom. With better results from the Thew shovels we soon realized that it was necessary to find some method of developing rooms faster than was being done with hand loaders in order to keep the Thew shovels in working places, and in November, 1923, the company purchased from the Joy Machine Company two Type 4 B U Joy loaders, and the installation of same met with the same indifference and antagonism from the employees as did the Thew

Jan 1, 1924

By C. A. Allen

In presenting a summary of the uses of fine and pulverized coal the writer has borne in mind that we are not trying to determine what a combustion engineer should know but we are only trying to find out in what ways the consumption of slack can be stimulated. First discussing the use of powdered coal it can be stated that it has passed the first experimental stage but is still capable of much development and improvement. It has already found successful application in stationary and locomotive boilers, cement kilns, calcining furnaces, reverberatory smelting furnaces and many other types of furnaces, such as open hearth furnaces and annealing furnaces. For stationary boilers it seems to have been thoroughly demonstrated that powdered coal is more efficient than stoker installations. Over-all efficiences of boiler and furnace in stoker installations of the best type run from 70 to 76 per cent; whereas the efficiency of powdered coal installations averages slightly over 80 per cent. However, due to the increased cost of pulverized coal, the increased efficiency of these installations over stokers, from a money stand-point, will not be more than 1 or 2 per cent. The fusing of the ash in pulverized coal installations has given some trouble but apparently is easily overcome, on the other hand the fine ash, which is carried along with the draft, causes trouble both in the boiler and by settling on surrounding buildings or ground. Offsetting the disadvantages the great advantages of pulverized coal for stationary boilers seem to be: First-the ease with which a change in the load on the boiler can be taken care of. Second-when a boiler is cut out for a short period the "stand-by" losses are much less and, Third-a much poorer grade of fuel can be used. In many cases where pulverized coal has been used it has replaced slack coal which is of little advantage to the coal operator. However,, in other places it has replaced gas or oil and this is where the coal man is interested. Pulverized coal has the same advantages as the liquid or gas fuel but the question as to which is preferable depends on their relative cost at the point of use. In small stationary boilers where stokers are not used, very frequently the larger sizes of coal are, and it would be an advantage to the coal industry for them to be converted so as to burn pulverized coal, but so far there are only records of a few of such small installations having been a success and there is apparently room for a large amount of experimentation. In furnaces, such as smelting and assaying furnaces, annealing furnaces, etc., slack coal is not used and where pulverized coal has been installed it nearly always replaces fuel oil or gas. Just how much increased consumtion of coal can be made by pulverizing it for use in furnaces of this type can not be determined but it seems worthy of investigation. For locomotive boilers pulverized coal has found some application up to date but where it was being used in the United States it was stopped when we entered the war. In Brazil, however, the Central Railway has been using pulverized coal for locomotives with excellent results. If it could be possible to apply it to locomotive use where fuel oil is now used, or the larger sizes of coal, it would certainly make a big difference in the slack situation. Now as to the uses of slack coal without pulverizing. The writer's investigations lead him to believe that the greatest opportunities in this direction are in the line of increasing its use by apartment houses and small home owners. In fact in looking into the subject I found that a number of men in Salt Lake City are using run of mine coal in the usual type of house furnaces, some of them by separating the fines and wetting them down before feeding to the furnace claim they get no loss whatever through the grate. However, for best results with fine coal different types of furnaces must be installed and for apartment houses it would seem necessary to have either a small automatic stoker or else spray the fine coal in with an air blast from

Jan 1, 1922

In this very interesting paper, Mr. Harrington mentions a considerable variety of materials suitable for use in the rock dusting of coal mines; this suggests that you may possibly be interested in same purely theoretical figures tending to show the superiority of gypsum for this purpose. Some of the gentlemen present have found difficulty in applying a thick, adherent coating of dry gypsum to the ribs and roofs of their workings, for which reason pulverized gypsum will perhaps be chiefly useful for the loading of barrier troughs. In view of the function that rock dust is expected to perform in case of a coal-dust explosion, it seems obvious that the most efficacious dust will be the one that can absorb the most heat and absorb it most rapidly. The customary rock dusting materials differ considerably in this respect, depending principally upon the facility with which they can be decomposed at the temperatures encountered in a coal-dust explosion. Such stable materials as silica, anhydrite and flue-dust vary but slightly in their heat-absorbing capacities, the specific heats of minerals in general ranging between 0.19 and 0.22; on the other hand, gypsum and limestone, as well as certain argillaceous materials such as shale, adobe, etc., are capable of absorbing additional heat through their chemical dissociation, although, as will appear later, it is questionable whether the amount of heat thus absorbed, in the case of limestone, shale, and adobe, is large enough to have any practical value. As to the temperature developed by a coal-dust explosion, the Bureau of Mines reports one test in which gold foil was melted, and others in which silver foil was melted, but not gold; hence 1832° F. (1000° C.) seems a reasonable figure to assume for purposes of calculation. Normal temperature is taken as 68° F. (20°C.). The other fundamental data required for the computations as cited by various authorities, are as follows: [Specific heats Gypsum : 0.259 Calcium sulphate, anhydrous. . .190 Limestone 0.216 Lime 0.239 Clay, shale, silica, etc. usually not exceeding 0.220 Carbon dioxide .:0.217 Steam (at atmospheric pressure)0.500 Heats of formation CaSO4+2H2O-4.606 Kg-cal. per gram molecule, or 48.2 B:t:u.' per pound of gypsum.- CaO +C0,42.5 Kg.-cal. per gram molecule, or 765 B.t.u. per pound of limestone. Latent heat of vaporization of water. from and at 100°C.. 535.9 Kg.-cal. per kilogram (964.6 B.t.u. per pound).] Computations will be based on the Fahrenheit scale and British thermal units, as probably more familiar in the coal industry. First as to the inert materials: their heat-absorbing capacity per pound is simply the product of their specific heat, say 0.22, multiplied by the assumed rise in temperature, 1764° F., or 388 B.t.u. per pound. Gypsum, CaS0, 2H.0, though apparently perfectly dry, contains 21% of combined water. When gradually heated it will have liberated three-quarters of its water freely by the time it reaches 250° F.; the remaining one-quarter is retained to a somewhat higher temperature, but the last of it will have been expelled at 482° F. For calculating the total heat absorbed in raising gypsum (or its products) to the temperature of a coal-dust explosion, no serious error will be intro-

Jan 1, 1925

By C. B. Huntress

"We have ourselves to blame in the steel industry for our condition." These words were addressed twelve days ago by James A. Farrell, President of the United States Steel Corporation, to his "comrades" at a meeting of the American Iron and Steel Institute. They carry a note of challenge to all industry, and particularly to the coal industry, where they point the way to the pressing need for operators everywhere to get their feet under one table. It is that note which I would stress to all producers. You have yourselves to blame for your condition. True, there are inter-district competition and competition of substitute fuels, but they'll always be with us, more or less, and the only sensible, sane course is to remove the evils within our respective districts, which can be done only by constructive effort along cooperative lines. It's the same story in Alabama, the same in Illinois and elsewhere. The larger number of the men gathered here are at the front, as it were, in the business of mining coal. They are the men who are doing a remarkable operating job. And naturally, the sessions of this annual meeting treat of news from the front, of technical problems. But, as in actual warfare, those at the front are often uninformed of developments in the rear. They keep on fighting without fully sensing the significance of a disaster at headquarters. You've played your eighteen holes today and evidenced the efficiency of your technique in the, production of coal. It is not amiss to take advantage of this moment, the nineteenth hole, to ponder over what it's all about. After all, what do improvements in the art of mining mean if business policies engulf you in red ink? To the extent that mechanization is a factor in increased overhead, which in turn increases the pressure to produce regardless of market demand, it only aggravates our troubles unless there is the controlling influence of coordinated effort.

Jan 1, 1931

The twenty-eighth regular meeting of the Rocky Mountain Coal Mining Institute, which was held jointly with the Utah Section of the American Institute of Mining and Metallurgical Engineers, was called to order at eleven o'clock A. M., Monday, March 11, 1929, President Otto Herres presiding. Introductory remarks were made by John M. Boutwell, Chairman of the Utah Section of the American Institute of Mining and Metallurgical Engineers, who outlined the intent and purpose of the joint meeting, and its co-operative program. He spoke of the in- creased recognition being given to men in the engineering profession by the public, which has recently been manifested by the election of President Hoover, an engineer of outstanding ability, and the re-election of Governor Dern to the Governorship of the State of Utah. He then introduced Governor Dern, a fellow member, to make the address of welcome. Governor Dern assured the meeting a hearty welcome. He spoke of Utah as one of the important mining states of the Union, particularly in metal mining; the magnitude of Utah as a coal mining state being limited only by its market; of the enormous coal resources of Utah, and the problems of the coal mining industry.

Jan 1, 1929

By D. Harrington

My acquaintance with rock, dusting as a preventive of wide spread explosions in coal mines dates from the fall of 1914 and the spring, summer and fall of 19.1.5 when I had an opportunity to observe the staging (both before and after) of several of the explosions in the Experimental Mine at Pittsburgh and saw violent explosions stopped by rock dust, also saw violently explosive coal dust made insensitive by use of rock dust to ignition or to propagation or spreading of an explosion. From this work I became a convert to rock dusting though I had previously been a firm believer in watering methods and am yet a firm believer that watering, methods have a well defined place in promoting the health and safety of our coal miners. In 1916, while in the Bureau of Mines service, I made an underground study and a report to the Bureau on the first extensively rock dusted mine, in the United States, the Delagua Mine of the Victor American Fuel Company near Trinidad, Colorado, there being then some ten miles of entry in that mine which had been kept well rock-dusted for at' least four years The dust used was " adobe" or surface soil screened from sweepings of the dry surface wagon roads through a screen with one-eighth inch openings, the dust giving about 20% through 200 mesh and about, 10% of approximately 1/8-inch size. The material was collected during dry weather by contract at $1.00 per ton (sacked) and was accumulated in summer and stored for winter and spring use. The dust was scattered through haulage entries by hand or by an electrically operated blower and was held on shelves along the ribs or between and on timber caps with from 1/4-inch to 2-inch thickness of the rock dust. The cost of maintaining the 10 miles of entry well dusted was about $1,500.00 per year or $150.00 per mile per year. Total cost of 'the rock dusting over a four-year period was about $6,000.00, about 2,500 tons of dust being used and 2,000,000 tons of coal produced; the above cost included about 1,200 days labor dusting at $2.50 per day, 2,500 tons of rock dust at $1.00. per ton and miscellaneous labor, material, repairs, power cost, etc., amounting to about $500.00. The cost per ton of coal produced for keeping 10 miles of entry rock dusted being about 3/10c. In addition to the rock dusting, some sprinkling was done, chiefly in the interior of the mine, costing about 2/5c per ton; and due to spilling of coal and sifting of coal .dust through loose cars on the entry floors, the floors of haulage roads were kept sprinkled between and just outside-the rails. Total cost of sprinkling and rock dusting was about .7/10c per ton much less of course than the same work would now cost. Between January, 1916, and July, 1924, my duties in the Bureau of Mines allowed me, to follow up and make underground inspections and reports on more than 20 coal mine explosions and fires in a number of states of the union and in this work a large number of samples of road, rib, and other dusts were taken to ascertain the effect of moisture, roof and floor dirt, etc., upon the propagation or the stopping of the explosion; also a large part of my work was to obtain evidence pro and con as to influences affecting the disasters and very prominent among those influences were the occurrence or use of water, water drippers, or ponds, as well as of sand, roof or floor rock or dust on floor, ribs, etc. The Dolomite explosion near Birmingham, Alabama, in November, 1922, and the Dawson No. 1 Mine Explosion at Dawson, New Mexico, in February, 1923 (at both of which I made underground inspection and report) both starting on main intake haulage road and both in mines which had fairly elaborate watering systems, convinced me that at least as far as freezing can occur on main intake air courses which also act 2s main .haulage ways, rock dusting is likely to be much more dependable than sprinkling. In making up the report on the Dawson Explosion to the Bureau of Mines (copy of which also

Jan 1, 1925