AMMONIACAL GAS LIQUOR. 



145 



operation is the distillation of the bituminous shales used in 

 the Scotch paraffin industry, while the production of pig iron 

 is sometimes effected by the use of coal instead of coke, and in 

 this case arrangements are sometimes made by which the 

 ammonia and tarry products which are evolved during the 

 first stages of the heating of the coal may be collected. 

 Another source of ammonia is the liquid condensed from the 

 ''producer gas" and "water gas" formed when a current of 

 air or steam is forced over red-hot coal. 



The product obtained in any of these processes is a complex 

 mixture consisting of an aqueous solution of ammonium sul- 

 phide, carbonate, thiosulphate, thiocyanate, and chloride. 



The composition of gas liquor may be gathered from the 

 following analyses of products obtained from the Leeds gas 

 works, I. in 1883* and II. in January, 1901 f : 



i. ii. 



Total ammonia ... 20'45 

 Total sulphur ... 3 -92 

 3-03 

 39-16 

 14-23 

 1-80 

 0-19 

 2-80 

 0-41 



Ammonium sulphide ... 



,, carbonate ... 



, , chloride . . . 



,, thiocyanate 



, , sulphate . . . 



,, thiosulphate 



, , f errocyanide 



19-45 grammes per litre 



4-22 



3-72 

 33-97 

 12-61 



0-93 



0-63 



3-84 



trace 



Organic bases and other substances are also present, but 

 were not estimated. 



In order to prepare a marketable commodity from this liquid 

 it is heated and lime is added. The ammonia volatilises 

 partly as carbonate and sulphide, partly as free ammonia, and 

 is received in sulphuric acid, whereby sulphate of ammonia is 

 formed, and carbon dioxide, sulphuretted hydrogen, and other 

 gases are evolved ; these are led away and suitably disposed 



* S. Dyson, J.I S.C.I. 1883, 229 ; J.C.S. 1884, abst. 928. 



t A. W. Cooke, J.. S.C.I. 1901. This sample represented the yield of three works, a 

 total of about 6000 tons of liquor. For an account of the composition of gas liquor 

 obtained at various stages of the distillation, &c., ?. L. T. Wright, Journal of Gas 

 Lighting 48, 280; or abstract in Jour. Soc. Chem. Ind. 1886, 655. 



