IRON 965 



fuel only : by a careful distillation of a known weight of coal, and analysing of the 

 products, he obtained results embodied in the subjoined table : 



Carbon . ,' '** . " . 68'925 



Tar . > '' . : - . 12-230 



; Water ... . . .: <.W; ,< V'i.; > ' v ... 7'569 



Light carburetted hydrogen . . ,KJO . . 7*021 



Carbonic oxide, . . . . , . . . . ... 1*135 



Carbonic Acid ,. ,. .. .. . .. . 1*073 



Condense^ hydrocarbon and olefiant gas . . 0753 



Sulphuretted hydrogen .. ;.' .. .. . 0'549 



Hydrogen,. . . .. . . , :' J jLi. . 0'499 



Ammonia.. ,. t . .. .. .. . .0*211 



Nitrogen . . . ';-" '*. ... 0-035 



100-000 ,r'.J 



Now, in the furnace,, the oxygen introduced by the blast is consumed in the im- 

 mediate vicinity of the -tuyere, being there converted into carbonic oxide, and the coal 

 loses all its gaseous products of distillation much above the point at which its com- 

 bustion commences, near, in fact, the top of the furnace ; the fuel with which the 

 blast comes into contact is therefore coke, and upon calculating the amount of car- 

 bonic oxide produced by the combustion of 68'925 per cent, of carbon, and the 

 nitrogen of the air expended in the combustion, we get as the composition by volume 

 of the gases escaping from a. furnace filled with Gasforth coal the following : 



Nitrogen 62-423 



Carbonic oxide . . . .-'..' j> . 33-163 



Light carburetted hydrogen . f.V; ' V .v ^ :. 2-527 



Carbonic acid ' 1.; -', 0-139 



Condensed hydrocarbon 0'151 



Sulphuretted hydrogen 0-091 



Hydrogen . , . . .'-. ;: ...,,. . 1-431 



Ammonia . . . . . O f 070 



100-000 



With this preliminary information, Bunsen proceeded to calculate the modification 

 of the gaseous mixture occasioned by the introduction into the furnace of iron-ore 

 and limestone. The materials used for the production of 140 Ibs. of pig-iron were : 



420 Ibs. calcined iron-ore ; 390 Ibs. coal ; 170 Ibs. limestone. From 100 parts of 

 the coal, 67'228 parts of coke were obtained ; but from this must be deducted 2-68 

 ashes, and 1-18 carbon entering into combination with the iron; which leaves as the 

 quantity of carbon actually burnt into carbonic oxide before the tuyere 63'368 ; part 

 of this carbonic oxide undergoes oxidation into carbonic acid at the expense of the 

 oxygen in the oxide of iron which it reduces ; a further quantity of carbonic acid is 

 derived from the limestone ; so that the gases returned to the mouth of the furnace by 

 the combustion of the 67'228 parts of coke, the reduction of the corresponding 

 quantity of ore, and the decomposition of limestone, consist of 



Nitrogen 282-860 



Carbonic acid 59'482 



Carbonic oxide . , 121-906 



464-248 



Add to this the products of the distillation of the coal, and we get the following as 

 the percentage compositions by weight and measure of the gases issuing from the 

 mouth of the furnace : 



By weight. By volume. 



Nitrogen . . . 59'559 60'907 



Carbonic acid . . . 



Carbonic oxide 



Light carburetted hydrogen 



Hydrogen 



Condensed hydrocarbon . 



Sulphuretted hydrogen 



Ammonia 



12-765 

 26-006 

 1-397 

 0-078 

 0-108 

 0-053 

 0-054 



8-370 

 26-846 

 2-536 

 1-126 

 0-112 

 0-045 

 0-058 



100-000 100-000 



