FUELS AND THEIR UTILIZATION. 51 



briquettes) per minute, and double compression is still extensively used in 

 Germany. The Couffinhal press, largely used in France, possesses also the 

 advantage of exerting a double compression, thus yielding bricks of equal 

 density on both sides with a minimum at or near the middle. 



LIGNITES IN SMELTERS. 

 The utilization of raw and dried brown coal in smelters was an object long 

 desired by iron manufacturers, and at the present a number of furnaces are 

 in profitable operation constructed for the use of this material. An appro- 

 priate construction of the smelters for this purpose is necessary, that the pe- 

 culiar composition of these coals, their loose texture and crumbling quality, 

 may not disturb the reducing process. The carbonization of the lignites 

 must be effected with the escaping gas near the mouth of the smelter, as, on 

 account of their just mentioned quality of crumbling and their predilection 

 to absorb moisture, they can not be subjected to a further transport. Kern 

 uses a combination of smelter and coke oven, the smelter not over seventeen 

 -feet in height. The escaping gas is utilized to carbonize the coal, to roast 

 the ores, and to heat the air necessary for the blowers. A cylinder contain- 

 ing the ores and prepared coal is placed above the smelter and parted from 

 it through a cone over which the material rolls into the furnace on lifting the 

 cylinder with levers. The escaping as passes around this apparatus, flows 

 through several canals, in which a number of cast iron retorts are placed to 

 carbonize the lignites, is used in the ore roasting ovens, and heats the wind 

 for the smelter on its further way to the chimney. There is nothing theo- 

 retically which will make the utilization of raw brown coal objectionable in 

 iron smelting. However, the preparing room must be large enough to per- 

 mit the coking of the coal inside the oven. A use of the unprepared coal 

 seems to be desirable, furnishing a gas of a greater heating capacity and a 

 larger quantity of it, by avoiding the very considerable cost of a separate 

 coking establishment. The only question is, what method can be most profit- 

 ably employed to supply all, or the largest amount, of firing material in use 

 by lignites for the manufacture of iron. To obtain this desirable end several 

 important points have to be considered. As mentioned, a large preparing 

 room, the inconvenient size of which can be somewhat diminished by work- 

 ing hot ores; and secondly, an oven of small vertical dimension, to lessen the 

 density of the smelting column. The use of coal of a larger grain is desir- 

 able, and blast of high temperature evenly distributed through the smelter 

 and under adequate pressure will greatly facilitate the process of smelting. 

 By observing these conditions an addition of from fifty to seventy per cent 

 of raw lignite has been made for a number of years at Zellweg, Germany, 



Kaian, Siebenbuergen, and other places. 

 11— preol. 



