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By F. A. Young

A description of the dry process coal cleaning plant which has been built and operated by St. Louis, Rocky Mountain & Pacific Company at their mine at Brilliant, New Mexico, should at first be a description of the special machinery which is used in this process. This equipment consists primarily of screens for sizing the coal into six different sizes all smaller than 1 ½ inch and the pneumatic machines for cleaning each size. These machines are patented and were manufactured by Sutton, Steele & Steele of Dallas, Texas, until a few months ago when all rights of sale were acquired by the American Coal Cleaning Corporation. These screens, a plan of which is now before you, are called anti-gravity screens because the coal travels up hill. The screens which we have at Brilliant are 3 feet wide and 7 feet 4 inches long. They consist of one upper deck which slopes upward in the direction of the flow of the coal, at an angle of 12 degrees. This deck is a wire mesh screen the size of which determines the size of oversize from that screen. Under this is a lower deck with a slope of 7 degrees. This is a solid bottom and is for advancing the undersize to the next screen. On account of the difference in pitch of these decks they are about 11 inches apart at the discharge end, which allows the oversize to be taken off at one or both sides and the undersize to fall only a few inches on to the following screen. This is perhaps the most valuable point in this patent as it allows any number of screens to be placed on a-level floor, tandem in a battery without elevating or rehandling the coal in any way. The length of the screens corresponds to the proper spacing of the cleaning tables which naturally operate on the floor below. I know of no other screen which can be operated in this way. The coal is caused to travel by a reciprocating motion. A shaft as shown near the center of the screen box and under it has an eccentric at each side of the screen with connecting rods attached near the rear of the screen box. The screen box is attached to the stationary under frame by means of cast iron plates extending full width across the screen box. These are placed at an angle as shown so that the forward motion of the eccentrics causes the screen box to rise as it moves forward and the backward motion drops the screen from under the coal thereby causing it to advance. The coal advancing over the screen cloth in this rolling or jumping motion causes very perfect sizing. It should be stated here that very accurate sizing is necessary for the success of the cleaning tables. The stroke is 1 inch and the speed 350 revolutions per minute. In describing the pneumatic cleaning table, I place before you a plan furnished by the makers. The basic principle is that if a film of coal one to two inches thick and all of nearly the same size pieces is placed on a flat perforated surface and a large volume of air passed through it, the lighter particles which are the clean coal will soon find their way to the top of the film, while the heavier particles, or waste, will remain on the bottom. The machine is built with a perforated deck about 4 feet square under which is an air chamber and air duct connecting with a fan which is part of the machine. The deck of the table has a reciprocating motion the same as the screens already described, which tends to advance the product up a slight slope which is adjustable. The coal is fed at one corner of the table as shown and the deck slopes also away from the feed and at right angles to the reciprocating motion. On top of the perforated deck are riffles about 2 inches apart and running parallel to the line of reciprocating motion. These riffles are about 1/2 inch high at the fan and feed side of the table and taper to nothing at the far side. When the coal is fed on to the table, the air through the perforations tends to raise it 'and roll it over these riffles down the slope toward the clean coal discharge. The heavier particles do not get over the riffles so rapidly and the reciprocating motion is constantly pushing them

Jan 1, 1923

Jan 1, 1923

[Page Minutes 5 Low Temperature Distillation and Briquetting 8 F. C. Miller. Discussion of Mr. Miller's Paper 11 Track Bonding 15 D. C. McKeehan. Discussion of Mr. McKeehan's Paper 16 Report of Safety Committee 19 Wm. Littlejohn 19 P. F. Patterson and G. A. Knox 20 D. Harrington, J. C. Roberts and Jas Dalrymple 22 Discussion of Report of Safety Committee 27]

Jan 1, 1923

By D. C. McKeehan

The importance of properly bonded rail joints has received the attention of The National Research Council, whose committee will investigate several methods now used and determine the merits of each as applied to street railways. The results of this investigation should be appreciated no less by the mining industry. Literature on the subject of bonding mine tracks agrees, as a rule, "that the work is poorly done." With present day facilities there is little excuse for inadequate track conductivity, and a job well done must be maintained in order to realize results. Many years ago The Union Pacific Coal Company installed their first haulage locomotive, and at that time used the channel pin bond for joining the rails. The system utilized 500 volts and the, relatively small current for a large amount of power, undoubtedly, contributed to the success of the system. The bonding of both rails was considered imperative in those days, while now the bonding of one, rail is considered sufficient in most instances. The recent installations utilizing 250 volts and correspondingly heavier currents required a more effective method of joining the rails for use as an electrical conductor. The company has used the arc-weld bond since its introduction in 1919. The art of electric welding found great favor for various methods of doing the work. The first arc-weld bonds were placed on the outside of they ball of the rail, but the bonds were ill-adapted to rails lighter than sixty pounds per yard, and the results were that grooved locomotive wheels or derailed cars removed the bonds. Familiarity with the process of electric welding brought forth numerous schemes for joining the rails. In one, instance the rails and splice-plates were welded together and with excellent results for a short time. Track movement and vibration finally broke the welds and the method was dis¬carded. Another scheme consisted of placing a channel pin over each end of an annealed copper wire about twenty inches long. The idea was to develop some way of using short lengths of scrap wire. The pin and wire were then welded to the base of the rail. Numerous joints made in this way are still intact, but successful welds were so exceptional that the practice was abandoned. Some of these bonds were welded to the web of the rail, with the result that practically all rails broke at the weld; however, this is our only record of broken rails with arc-welded bonds. At one time a quantity of No. 2 bare iron wire wasp available and was tried as a bond and proved very satisfactory. Two or three strands twenty inches long were used and were welded to the base of the rail. The method was cheap and effective and of some merit for light rails on temporary track. The use of iron wire was criticized because it did not give a balanced circuit; that is, one having equal carrying capacity for trolley and track circuits; and I am of the opinion that this is not always necessary. The total length of bond that is in circuit is so small that it contributes very little additional resistance to the complete circuit consisting of trolley wire, rails and bonds.

Jan 1, 1923

H. C. GLAZE: There is no question in my mind that the day of direct current distribution is practically ended so far as large coal properties are concerned. Another thing that Mr. Drennan touched on that is of the utmost importance, is that of voltage-voltage to the various pieces of equipment inside the mine. You all know how expensive it is to have motors in operation in important places where the voltage .is about half that which the motor should have. This is particularly true in the direct current system. It slows down production, causes burnouts and destruction to apparatus, and is a question that you men have got to go into. It costs a great deal of money, as Mr. Drennan pointed out, to take care of this. The wires are large and cumbersome, while; on the other hand, with an alternating current system you can use a minimum amount of wire. We have installed this class of equipment with so-called "pick-proof" cable of 2,200 volts down slopes, and I have never heard of any trouble whatsoever from this cause.

Jan 1, 1923

By A. L. Jones

The subject assigned to me of "The Power" Problem of the Mine" is so broad that I have decided to confine myself to the question of the power supply itself, rather than the application of electricity throughout the property. We will look over certain economic aspects of the problem, particularly in the way it affects the mine manager or executive and his attitude toward the power plant. The accepted method of power application to the mine is by electric power, and the experience of each of you is that the job is never complete as you are always undertaking some further electrification which necessitates the stiffing up the power house to care for the additional load. The mine executive, then, is wrestling almost continuously with the problem of his power plant. Either it is overloaded and must be enlarged and rebuilt; or its operating costs are excessive; or it breaks down and limits coal output; or some one wants to sell new and improved machinery, until the manager almost hates the thought of such a restless part of his property. If he purchases power, every day new uses for it seems to be found. In many ways this unrest is due to short-sighted policy toward the problem, and the tendency when the problem of extension has to be met, to dispose of it in the cheapest way and without thought as to where the future is leading. The day when each opening had its own boiler plant, steam hoist, steam driven fans, steam pumps, steam loaders, etc., seems to be far behind us. The recognized method of power distribution today is by electric power, except for rather limited applications of compressed air; most of which is electrically compressed. During fifteen years contact with mines of Colorado and Wyoming the writer has seen nearly every mine power house double or triple in capacity or abandoned in favor of purchased power, worn. out and inefficient machinery thrown out, isolated boiler plants dropped, seam pumping at great depth changed to electric drive, all resulting in greatly reduced labor and fuel costs. Power costs, which in such isolated plants were considered normal, would be unthinkable today. One property where the main power supply was by compressed air from steam driven com¬pressors used under boilers 8.35 per cent of all the coal mined. The cost of power was 12 1/2 cents per ton of coal mined. Another property of four openings, each with its own boiler plant and usual equipment of hoists, pumps, etc., had a power cost of 10.3 cents for each ton mined; and these were days when you did not get very high prices for coal. Another property operating two mines mostly by steam used 11.1 per cent of the coal output under their own boilers and the power cost was 19.45 cents for each ton mined. Each of these properties is now electrified and power costs are from 3 to 4 cents per ton, and the fuel burned runs from 1 to 2 per cent of the output. With the broadening market and high prices for slack coal and the high prices for labor in boiler and engine rooms, the cost of steam is reaching a high figure, and efforts must be made to keep this down, by more efficient steam production and by utilizing this steam in better machinery which will increase the work done by each pound of steam. It must not be overlooked either, that the plant which is very wasteful of fuel is usually a pretty old one and one far from reliable. In a general way the more efficient the plant, the greater its reliability. Ample and reliable power supply means ability to get out coal when there is a market. The increasing use of purchased power is largely due to changing conditions which are tending constantly to push up the cost of power, unless the most efficient machinery is used and large scale production possible. The

Jan 1, 1923

CHAIR: I see a great many safety men in the audience and I hope you will all take part in using up the time that we have left. The point brought up by all was the necessity of education. It is very hard to know just how this is going to be done. We get very little encouragement to do this. At a recent meeting at Rock Springs, 100 in attendance, and most of them mine officials. Another condition which contributes to accidents is the labor turnover in many of our States. With many companies I am told from actual statistics the labor turnover is 125 per cent. Each field has different mining conditions so that men coming from one field are not always familiar with the mine conditions in the field they come to. These are conditions which have to be overcome. WM. LITTLEJOHN: Mr. Harrington brought up the subject of sprinkling. I will try to tell what we are doing at the Utah Fuel Company camps. Our dust at Castle Gate is the most inflammable gas that has yet been tested at the Pittsburgh station of the Bureau of Mines, so it is up to us to use every precaution to keep it down. I will try to tell what we are doing regarding sprinkling from tanks. We now have in operation two tanks in our locomotive roads, one in Castle Gate, one in Sunnyside. These tanks are something like 500-gallon tanks with pump on one end of truck which gets its power from the power wire and has a half circle perforated pipe on the other end of tank. This is simply hooked on to the locomotive. When the pump is started up it throws a fine spray of water all around which wets the roof, the sides and floor. We found this very successful from an economical as well as a working standpoint. A roadway that we probably would have had to pay a man at least two shifts for, covering the full distance, with the ordinary hose and spray, we can do in half a day and do it more thoroughly. We are also figuring on at the present time using the same system on rope haulage ways, which of course will have to be run by a reel from the feed lines, handling say four hundred feet each way before reconnecting. We haven't got it finished, but are working on it at the present time. MR. COLBURN: I would like to say a few words -about this question of education. Education was mentioned by all three sections of the Safety Committee. Education regarding safety might be divided into two branches. One branch is for the official at the mine to keep him acquainted with the latest developments in safety equipment and safety methods. The other part of education is for the workmen. The United States Bureau of Mines is co-operating in both directions. Safety Clubs are organized around the Bureau of Mines First Aid Training, but it is the idea to expand those clubs and teach the miner the advantage of such-things as the closed safety lamp, and also the regulations that have been made for his safety. In Illinois we can't operate with the closed lamp, because the miners in that section of the country are not educated to the advantages of the safety lamp. Another form of education has been taken up by the National Safety Council, consisting of voluntary organizations similar to the Institute, to which all mining men are invited to attend. Such conferences nave been held in the Lake Superior district, in Butte, and in Globe, Arizona, this year. These are to be extended throughout the coal mining regions. CHAIRMAN PRYDE: The Union Pacific Coal Company has also built two tank cars of 600 gallons capacity each. The tanks are connected with hose, so that water can flow from one tank to the other. A centrifugal pump is mounted on a truck, and connected to the front tank. This pump takes its power from the trolley wire. The discharge from the pump is perforated, so that it sprays the floor and sides of the entries. We expect to use this water train on main haulage ways where we have no sprinkling line.

Jan 1, 1923

Jan 1, 1923

By F. C. Miller

The briquetting of fuel is an industry centuries old and has followed the hammer and tongs method of making use of any by-product fuel by the simple process of sticking the mass together with anything that will stick. If fuel briquetting, as an industry, once in the lead over coal mining, had kept pace by introducing science, there would not at this time be the mad scramble to look up the fuel briquette family tree and accept every new method as fruit without the cultivation that makes fruit worth while. Cultivation of industry is a mass of evidence showing a tremendous expenditure of money for mistakes paving the way to success. Cultivation of the mining industry is practiced by nations and low temperature distillation and fuel briquetting will in the near future receive the same consideration. Fuel briquettes were used as a winter fuel in Ireland and Scotland before the discovery of America' or the introduction of coal as a fuel to replace briquettes in Ireland. This industry was practiced by the peasants who collected peat from the bogs and cut it into brick-shaped blocks, which were set up to dry in the sun and stored under cover for use or for sale. Demand for peat briquettes led to competition that resulted in a highly refined fuel. In some localities the peat was ground and purified from the earth by washing before placing in presses to squeeze out the excess moisture and form a block of peat about four inches thick. These blocks, after standing in the sun for a few weeks, were cut into briquettes about four inches square by twelve inches long and moved under cover where they remained until thoroughly dry. In this form peat makes an excellent fuel with considerable heat, small amount of smoke while burning, and tough enough to stand hauling in carts and boats without breakage. Slack from domestic coal, non-coking and anthracite, has until recently commanded a very low price and the attention of briquette men has centered on ways and means of preparing this class of fuel for the market in the form of briquettes. Industrial plants with automatic stokers have taken kindly to cheap slack or slack that was cheap because the price has been boosted to a figure where the cost of slack plus the cost of binder and operation makes fuel briquettes somewhat expensive. However, fuel briquettes are being turned out in commercial quantities to compete with prepared lump coal and the demand is in favor of the briquette man. Science has been called to aid the briquette and it is possible to purchase a complete coal briquetting plant that will turn out between four tons per hour and thirty tons per hour of briquettes at a calculated cost per ton to cover material and every item down to insurance on the plant. A few briquettes are being ' made with a mixture of- Portland cement and pulverized coal, where this class of briquette is cheap in the making, there is the increased amount of ash due to the cement to contend with and the briquette is not one that can compete with lump coal. Most binders have a fuel value, such as coal tar, pitch, asphalt residium, flour, glue and secret binders. Most briquettes are of an egg shape, weighing between one and one-half ounces and five ounces, pressed to form with a pressure varying between 1,000 pounds and 2,500 pounds per square inch. This' pressure, together with the binder, make a lump of fuel harder than most grades of soft coal. Most of the briquettes are free from pitch odor, and any tendency to leave a trace of the binder on the fingers, easy to handle, quick to, ignite, high in heat value and capable of indefinite storage without any change. Evaporative efficiency of briquetted fuel in stationary, marine and locomotive boilers has proved that a great many low-grade coals can be fired successfully in the briquetted form, where the same fuel without briquetting failed to give boiler rating.

Jan 1, 1923

Jan 1, 1923

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 C. E. Drennan

Your Chairman and the Program Committee have limited the time allotted to me, and so, with your permission, I will omit the preliminaries, and wade right into my subject. I believe I am safe in taking for granted that you are all agreed that electricity is the most feasible means of transmitting the power used in coal mining. If you are not, then the papers read before the Association in previous years have failed of their object. If you are so convinced, the only question is as to the choice between alternating and direct current, and the voltage. Fundamentally, this is primarily a matter of dollars and cents. With the sole exception of your trolley locomotives, there is no part of your equipment that cannot be operated as well on alternating as on direct current. With your pay rolls at their present high level and the efficiency of the labor you employ at the stage it now occupies, I believe you will agree, first, that everything possible must be done to increase the tons of coal produced per man employed; and, second, that ample power at all times must be available at every machine so that every one of your men can really get out a day's work without any avoidable delay. Speaking Electrically, all this means is a machine instead of a man wherever it is possible for a machine to do a man's work, and full voltage at the machine always, so that there can be no excuse for the work not being done promptly and efficiently-and dependably. The real reason for the selection of one kind of current or the other can best be understood by considering the formula which determines the size of wire required for transmitting electrical energy. The size of the copper required, and, consequently; its weight and cost, depends upon four factors: 1. The amount of energy or power to be transmitted. 2. The distance to be covered. 3. The percentage of loss allowed. 4. The voltage at the receiving end of the line. These factors enter into the problem to different extents, and, briefly, the size of wire depends directly upon the amount of power and the distance transmitted, and inversely upon the percentage of loss allowed and the square of the voltage. From this it will be seen that, with the amount of power and the distance fixed, if the loss is to be cut in two, the wire must be doubled with a given voltage, while if the loss remains constant and the voltage is doubled, the wire may be cut in four; that is, reduced 75 per cent in weight and cost. Now, standard motors are designed and recommended by their builders to run within a range of 10 per cent under voltage to 10 per cent above voltage - 440-volt motor, then, should preferably not be operated on less than 400 volts

Jan 1, 1923

FEBRUARY 26TH. MORNING SESSION: The sixteenth regular meeting of the Rocky Mountain Coal Mining Institute was called to order in one of the private dining rooms of the Albany Hotel, Monday morning, at 11 o'clock, with the President, F. W. Whiteside, in the chair, one hundred and one members being registered. The minutes of the previous meeting were read and approved. The Treasurer reported the finances of the Institute in excellent shape. The President appointed J. B. Marks, J. S. Veach and W. A. Ream as a Resolution Committee, and Frank A. Young, M. B. Urquhart and G. A. Murphy a Nominating Committee. There being no further business the meeting adjourned. AFTERNOON SESSION: The afternoon session was called to order in the Ball Room of the Albany Hotel, with approximately one hundred members present, President Whiteside presiding. A. L. Jones read his paper entitled, "The Power Problem of the Coal Mine," and C. E. Drennan, his paper, "Why Alternating Current." These papers were thoroughly discussed, after which the meeting adjourned. EVENING SESSION: At 6:45 p. m. two hundred and fifty-three members and invited guests met in the Ball Room of the Albany Hotel for the banquet. Harry F. Nash was toastmaster, and George Sanford Holmes the principal speaker. Following Mr. Holmes speech, H. N. Wheeler delivered his humorous oration of the "Annexation of Cuba;" following this certain members of the Institute gave an entertainment depicting a fictitious meeting of the United States Coal Commission. Chester Mott, formerly a member of the Institute wrote the words and songs of the entertainment, and directed it. After the show the assembly enjoyed a dance.

Jan 1, 1923

PRESIDENT WHITESIDE: If the chair may be pardoned, he would like to say he knows something of the work of this committee, and I assure you that they have all worked faithfully and hard, holding meetings at least every other day, and sometimes oftener, hustling money and going through all the different work necessary to bring about and to make a successful occasion of this kind, and I-who really acted as an outsider and viewed their work-was certainly appreciative of their efforts, and I know you would have been had you been able to see how hard they all worked. One of the sad things in life always is when one becomes a "has-been." I have been more or less active in the work of the Institute ever since its in¬ception. Just why the high honor of President was conferred upon me I have never been able to fathom, but my time is about over and I am about to join the "has-beens," and while the position naturally has entailed a certain amount of work, it has been very pleasant work, and when one has the hearty co-operation of his fellow workers, such work is always a pleasure. It is, therefore, with a certain amount of regret that I lay down the gavel and take it up again to present to my successor; but in doing so, I wish to thank you, one and all, for your very hearty help and co-operation, and to wish my successor, Mr. George B. Pryde, all the possible success that can be his. Mr. Pryde. (Applause.) MR. PRYDE: I will make no extended speech at this time. I think possibly the next year I will have enough opportunity to do that; but I had a letter from my friend, Murphy, before this meeting, and he thought we were going to have a very good meeting; but I don't know the motive behind his letter. (Laughter.) I remember the story about the Scotchman who went to see the doctor, and the doctor said: "Sandy, you drink any?" "Oh, yes." "Well," he says, "you have got to cut that out. Do you smoke?" "Oh, yes; I smoke a great deal." "Well, you will have to cut that out also." And Sandy picked up his hat and started for the door. "Wait a minute, Sandy; you haven't paid me for my advice." "Yes, but I am not going to take your advice." (Laughter.) But I am deeply appreciative of the honor you have conferred upon me, electing me to be head of this Institute for the next year. I have belonged to this Institute, I should say, ever since it has been organized. This present session especially has been a very good session. As I look back over the different meetings, I think this one stands out among all the others in the papers presented and the spirit of co-operation that prevailed among the members here, and I am not going to ask your co-operation during the year; I am sure I will get it from all of you. I want to thank you for the honor conferred upon me. (Applause.) MR. WHITESIDE: The retiring President did not quite follow the reading of the by-laws, I think, in which it says that immediately after the election of a new President, the new President shall assume office, and I got so busy I forgot all about that. The committee which the chair decided to appoint is as follows. This is to formulate safety rules: For Utah, John Crawford, William Littlejohn; for Wyoming, Peter Patterson, Glen Knox; for New Mexico, William Risdon, Allan French; for Colorado, James Dalrymple, J. C. Roberts; and last and surely not least, as chairman of the committee, Mr. George B. Pryde. (Mr. Pryde later appointed D. Harrington as a member-at-large.) C. M. GODDARD: Mr. Chairman, we all realize that in a gaseous mine the application of, safety measures transcends everything else. Machinery is installed 100 per cent safe, as they might say, to take care of any condition

Jan 1, 1923

BENEDICT SHUBART: I am rather surprised at one statement of Mr. McKeehan, that he found it satisfactory to bond only one track. It has always been my idea of good practice to bond both tracks and cross bond frequently, so that in case of any break in the bonding of one track, which frequently occurs, there will be no interruption in the circuit.

Jan 1, 1923

MR. SHUBART: Mr. Miller's paper mentioned the two processes that seemed to be a success, the Smith process and the Piron process. I suppose the main difference is this, that Smith's process is to furnish domestic fuel and the by-products while the Piron process that Ford is installing is for fuel for power plants. I would like to ask Mr. Miller something about the commercial cost of the process. With the briquette you must make it cheap enough to sell. What are the commercial possibilities of Smith's briquette? MR. MILLER: It is pretty hard to say what the cost would be at this time, owing to the fact that slack has advanced double, or even more at the time I was in New York with the plant, but at that time it was costing $1.10 for the operation. You can add to that, of course, the cost of the coke. One dollar and ten cents was the entire cost of plant operation. It takes about one and one-half tons of coal to make a ton of briquettes. One dollar and ten cents takes care of all the material, cost, labor, handling, etc. Labor was much cheaper then. I would say it would cost about $2.20 now. The cost of coal is what you can buy it for on the market. I don't think, however, that the carbocoal process will ever meet with any great favor for the simple reason that it is really a prepared fancy fuel. It is going to be nice for people in offices where they want a grate or for families where they want a nice clean fuel. It leaves no stain on the fingers, no odor to it. It seems in carbonizing coal we change the carbon molecule. For instance, we are all familiar with the diamond. It is carbon, yet it requires a tremendous heat to burn a common little diamond. But you can set a piece of charcoal afire, which is also carbon, with a match. The molecular form has been changed in carbonizing coal, i. e., it is larger. Carbocoal will fire very readily, it can be started with a piece' of paper. I think the Piron process will be the process, i. e., to simply take out the tars and light oils, then fire direct-have the distillate plants right on the job. CHAIR: Can Mr. Shubart tell us something of the mechanical part of the Piron process? MR. SHUBART: The Piron process is of interest because Mr. Ford is taking it up. He has made so few mechanical mistakes it makes us feel that it is a success. Piron is a chemist of high accomplishment and reputation. The thing about the proces is its simplicity. Mr. Smith's is a very elaborate process, but Piron has gotten around all that. Piron feeds the raw coal in at about one-half inch mesh or smaller. He feeds it into a retort about 55 feet long, 16 feet wide over all. He has a hearth about 6 feet wide and the length of the retort. The base of the hearth that carries the coal is a conveyor, a flat cast iron conveyor, a very massive affair, very accurately made, so that there is no loss of coal. Between the upper and lower strands of the ' conveyor is a bath of molten lead which gives an accurate control of temperature. For best results he must have temperature of not under 800 F., not over 1,300 degrees F., about 1,100 or 1,200 F. seems to be ideal for getting greatest yield of oils and the best tars and other by-products. This lead bath has a system of flues running through it that

Jan 1, 1923

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 John Bevan

In a discussion of the personal dangers that may arise from mine gases, it is necessary to take into consideration the gases which may result from an underground fire, or a fire in or about the downcast shaft, and the methods of avoiding or minimizing the danger arising therefrom. In all cases of the combustion of carbonaceous material such as coals and timber, carbon dioxide and water vapor are formed. In cases where the air supply is limited, some carbon monoxide is produced, the quantity varying with the readiness with which the oxygen from the air can get into intimate contact with the consuming carbon; in addition to these products there may be produced large volumes of irritating fumes consisting of unconsumed vapors' distilled from the burning material. Apart from the physical distress that may be caused by the irritant action of the fumes, the chief danger to life underground arising from a fire in or about the downcast shaft or intake airways is due to the carbon monoxide which the smoke is almost certain to contain. The physiological effects of this gas have already been discussed in mining papers and ref¬erence should be made to this. The prevention of fires at the surface near to the mouth of the downcast shaft, or in the shaft itself, or at the bottom of the shaft, usually lies outside the duties of the fireboss. An outbreak of fire at such places would, however, immediately foul the air current passing into the mine, and, assuming the men were in the mine, create a situation demanding urgent attention of the fireboss. As a rule, each case of fire creates its own problems, but in all cases the guiding principle should be to restrict the poison-laden 'air to the smallest part of the mine that is practicable, by opening separation doors, or breaking down selected stoppings at the most accessible points near the seat of the fire, so that the gases and smoke may pass directly into the return and so to surface. In the case of a shaft fire it will have the effect of fouling both shafts and in the case of a fire in an intake airway, both roadways leading to the shafts. It requires the use of some judgment. Therefore, in circumstances as to whether men inside the mine should attempt to escape to the shafts or should remain in the mine, and attempt to protect themselves from the poisonous air by suitably short circuiting the air-current and retiring from the main air-ways. In order to make such restraint easier, it is very desirable that all mines should be equipped with telephone communication from all sections of the mine to the surface so that men in the mine may be informed of what is being done at the surface to secure their safety, or instructed as to what they themselves should do. In cases of fire in or about the shafts, the question of the reversal of the air-current will probably arise. Should this be decided on by the management at the surface, the fireboss in the mine may have to give some attention to the effects which this action will have on the circulation of the

Jan 1, 1922

FEBRUARY 20TH. MORNING SESSION: The fourteenth regular meeting of the Rocky Mountain Coal Mining Institute was called to order in the Magnolia Room of the Albany Hotel. Monday, February 20th at 11 o'clock A. M., with the President, Mr. R. M. Magraw, in the chair, sixty-two members being present. The first number upon the program was the reading of the minutes of the previous meeting by the Secretary. There being no corrections or alterations, the minutes were approved as read. As Mr. Dan Harrington was unavoidably absent, his paper, subject: "Coal Mine Accidents and State Mining Law" was, by request of the President, read by Mr. J. Q. Lalor. Following this was a short discussion. There being no further business the meeting adjourned. AFTERNOON SESSION: The meeting was called to order in the Magnolia Room of the Albany Hotel at two-thirty o'clock P. M. with President R. M. Magraw presiding, fifty-eight members being present. Mr. Ben Shubart and Prof. J. C. Roberts were appointed a committee to draft and telegraph a message of condolence to Mr. E. S. Brooks of Rock Springs, Wyoming, on account of the recent death of his daughter. The com¬mittee submitted a copy of the following telegram, which was read by the Secretary: "E. S. Brooks, Rock Springs, Wyoming. We extend to you and your family our sincerest sympathies in your deep affliction. (Signed) THE ROCKY MOUNTAIN COAL MINING INSTITUTE." The following resolution was next presented by the Secretary and upon motion, duly seconded was carried by a unanimous vote: WHEREAS, it has come to the knowledge of this Institute that the Coal Mining Course of the Colorado School of Mines has been abolished; and

Jan 1, 1922

By Graham Bright

Up until a few years ago most of the electrical equipment used in the mines of this country was developed for industrial purposes and was adapted for use in mines by slight modifications. It became apparent, however, that mining conditions differed widely from most industrial applications and it became necessary to design and develop apparatus, particularly suited for use under mining conditions. Most of the electrical apparatus used in mines today, however, does not owe its success entirely to mining development, but in many cases developments in other branches have been taken and improved upon and modified to meet mining conditions. Power Plant: In the earlier days the power plant for the production of electric power usually consisted of fairly small belt driven direct current generators operated from reciprocating non-condensing steam engines. Today where possible the mines purchase power from central stations and where not possible it is ususally produced from turbine driven plants using non-condensing turbines for the smaller plants and condensing turbines for the larger plants. The bad water conditions at many of the coal mines in this country is, responsible in a large measure for the high cost of upkeep and repairs in isolated power plants. This feature with the type of labor available makes it difficult to operate an isolated plant condensing except in the larger mines where water conditions are good and the apparatus can be taken care of. The geared turbine is a particularly simple and rugged piece of apparatus and requires very little attention over long periods of time. Hoists: The first electric hoists to be installed used various types of motors designed for railway or industrial purposes, and the control furnished was far from satisfactory. Today most of the mine hoist motors are of the alternating current type, especially designed for hoisting service. The control for motors of 200 H. P. or over is usually of the magnetic of liquid rheostat type, and as built today will operate over fairly long periods with a very moderate cost of up-keep. Hoists of 1000 H. P. or larger are usually of the direct current type using field control and receiving power from a flywheel or synchronous M. G. set. Hoists of this type have made remarkable records in regard to continuity of operation and low cost of up-keep. Where high speed operation is desired in either coal or metal mines, the D. C. equipment using field control and a separate M. G. set to supply power to the hoist motor is not only the safest and most economical but in many cases is the only type of equipment capable of satisfactorily obtaining the output required. A number of improvements have been brought out with the field control scheme in connection with the acceleration, retardation, overfeed and overwind of the hoist. With these new developments the hoist operator can no longer abuse the hoist by improper manipulation of the control handle. Until a few years ago the matter of safety devices was not given much consideration when installing hoisting equipment. At the present time the safety devices are considered one of the most important items in connection

Jan 1, 1922