46 THE IRON ORE DISTRICT OF EAST TEXAS. 



basin. This construction facilitates the removal of the prepared product. 

 The process, as may be seen at a glance, is continuous. The filling from 

 above corresponds to the removal of the coke below. One hundred pounds 

 of lignite furnish fifty pounds of coke, on an average, and also about five 

 hundred cubic feet of gas, which, of course, is used for the coking process. 

 The product obtained is of a deep black color and of a shining fracture. The 

 coke, after being ground in a common grist mill, is washed to remove the 

 impurities, ground over in a moist state, dried, and is then ready for use as 

 lamp black. Ground in a dry state and less fine, the coke is in demand as 

 filter coal, or for the manufacture of gunpowder. 



A number of improvements have been made by various manufacturers in 

 the construction of coke ovens, of which a few will be mentioned. The re- 

 torts have been placed in a horizontal position, with iron covers in front. 

 The filling is effected as in stone coal retorts used in the manufacture of illu- 

 minating gas, and the removal of the coke is through bent tubes connected 

 with the back of each retort and of equal dimensions with it. The ends of 

 the tubes are immersed in water. A very ingenious apparatus has been sug- 

 gested by Richard Wintzeck essentially differing from ovens of older con- 

 struction in the following feature. An air canal is placed below the base of 

 the oven, which receives heat from the escaping vapors of the coking room 

 and conducts the warmed air through fissures in the base of the oven into 

 that apartment. The high temperature of the air causes instant ignition of 

 the distilling vapors of the coal lumps, hastens the process, and produces a 

 more complete coking of the coal. 



Ovens which, together with the manufacture of coke, make it an object to 

 increase the production of ammonia and tar, have largely taken the place of 

 those which neglect these products. The following is their distinguishing 

 feature: The distilling vapors produced by the coal are drawn into an ap- 

 paratus serving for the condensation of tar and ammonia, and thence returned 

 to the oven, where they enter heated canals. Below the base of the oven 

 they are mixed with warm air, and undergo combustion here as well as on 

 their way to the chimney. As soon as it has sufficiently heated a system of 

 flues, the progress of the escaping fire gas is reversed. Thus the gas coming 

 from the condenser passes these heated canals, while the escaping fire gas 

 serves to reheat the parallel system of flues, cooled by the gas on its former 

 way from the condenser to the base of the oven. 



Various improvements have been made since in the construction of the 

 coke ovens, and C. Otto describes a coke factory now in operation for a num- 

 ber of years at G-ottesberg, Germany. Its principal feature is a connection of 

 the ovens with Siemen's gas regenerators, and the results are so favorable 

 that the larger number of factories in Germany are operated on this plan. 



