40.33 7.50 Average of the twenty-six samples..... 52.08 Deductions from Analyses.-The method of analysis employed in the tables given above differs from that commonly used for lignites, in computing the percentage of moisture first, and then, after expelling the moisture, in determining the amount of the other constituents. The percentage of fixed carbon, volatile matter and ash is made somewhat higher than when the undried coal is analyzed. The practical difficulty in bringing the lignite to the laboratory without partial drying, however, makes it much more practical to compute their composition on a dry basis. Even when allowances is made for this method of computation the percentage of fixed carbon is high enough, if this alone. is considered, to prove these coals from the lignites and place them with the semi-bituminous or steam coals. The content of water, however, about 30 per cent, restricts them to the former class. EVAPORATIVE TESTS. More satisfactory than either chemical or calorimetric tests are practical evaporative tests carried on with boilers of standard patterns. A number of such tests have been made and in some cases in the same boilers and under practically the same conditions eastern coal has been tested, so that knowing the price of each coal at the point given, it is possible to determine quite definitely the economy resulting from the use of lignite. The following test was made at the asylum for the insane at Jamestown, by Chief Engineer Thos. Pettigrew, whose careful study of proper methods for burning lignite has greatly advanced the lignite industry. The statement introducing the test is written by him: "The use of lignite coal at this institution of (asylum for the insane) started in 1890. Since that time we have used it continually for generating steam, and for the past eight years have used it exclusively for cooking in the general kitchen of the institution. Lignite coal can be burned in any furnace that burns hard or soft coal. "The coal was burned on the soft coal grate and furnace up to the winter of 1894-5, when there was a change made in the furnace by arching over the grate with fire brick, and using the forced blast with a fan, which very much increased the value of the coal for making steam, by getting more benefit from the hydro carbon of the coal. "Eastern bituminous coal was tested against lignite in 1894, which gives the value of Dakota coal in comparison with the best bituminous coal in the market (which is Youghiogheny coal). I tested Youghiogheny coal first with the boilers before making any alteration for the lignite coal and there was little difference between the tests of lignite coal. We find from our experience at this institution that the coal fresh from the mine gives us as good results as the coal when dry. One pound of lignite coal fresh mined will evaporate as much water as a pound of lignite dried. The Slab in the Foreground Illustrates the Woody Structure Sometimes Found in Lignite. The Wall of Lignite Behind it Shows the Manner in which it Checks on Drying. Date of test.. Duration of test... Average temperature of feed water The following table shows the result of the tests made here : Total water evaporated at temperature of feed 8,837 lbs 14,157 lbs The cost of Youghiogheny lump at Jamestown was $6.80 per ton and of lignite $2.80. Result of Evaporative Test Made by the Missouri Valley Milling Co., at Mandan.-Fuel, Lehigh lignite. Duration of test.. Kind of Furnace.. Grate surface.... Width of air space in grate. Water heating surface Ratio of water heating surface to grate surface. Average steam pressure.. Average temperature of feed water entering boiler.. Moisture in coal...... Coal consumed per square foot of grate per hour.. Cost of coal delivered at mill per ton... Total cost of coal...... Total weight of water fed to boiler.. Water evaporated per hour from and at 212o Horse power developed.... Cost of fuel for evaporating 1000 lbs. of water. Average horse power of engine.. Cost per horse power per hour. 11 hours. Smith-White .30 square feet 4 inch .1,549 square feet 51-1 ..104 .175o F .12,221 lbs. 23 per cent .37 lbs $1.60 9.77 5,635 lbs .5,554 ..163 .1734 cts. .190 .0047 The mill has a capacity of 450 barrels of flour per day, and the cost of fuel when lignite is burned per barrel of flour ground. is 4.46 cents. |