[stan-sfield-gilmore] carbonization OF LIGNITES 87 



bonized what influence on the results have: — the final temperature 

 to which it is heated, the rate of heating, the duration of heating, the 

 pressure under which it is heated, and the atmosphere in which it is 

 heated ? The results to be examined included the yield and calorific 

 value of the carbonized residue, the yield and calorific value of the 

 gas generated, and the yield and economic value of the tar and other 

 by-products produced. 



Practical difficulties make the exact temperature control desired 

 impossible on any but small samples; yet the yields of gas and by- 

 products from such small samples are too small for study. It was 

 therefore decided to study first the effect of the above conditions on 

 the yield and calorific value of the residue from small samples, and to 

 study later the by-products in a series of experiments on a larger 

 scale. The first series of tests is now completed, the methods employed 

 and the results obtained being stated below. 



EXI ERiMP:NTS. 



Coal. The particular coal chosen for these experiments was, by 

 the advice of the Saskatchewan Government, taken from the Shand 

 Mine of the Saskatchewan Coal Brick and Power Co. The sample, 

 which consisted of a single lump of coal shipped by express from the 

 mine in a wooden bo.x, was crushed, and then ground to a fine powder 

 in a ball mill. For con\'enience of manipulation, and as a prevention 

 against the rapid change which a powdered coal undergoes owing 

 to moisture loss and oxidation, this powder was briquetted in a small 

 hand press. The briquettes were cylindrical, \" diameter, about \" 

 long, and ran about 5 or 6 to the gram. They were stored in stopped 

 weighing bottles until required, and from time to time control moisture 

 determinations were made upon them. It might be noted that 

 during a period of 2 months the moisture content fell only 1% from 

 an original of over 30%. 



The average analysis of this coal was: — Moisture 31-8%, Ash 

 5-2%, Volatile Matter 28-9%, and Fixed Carbon 34-1%. Its gross 

 calorific value was 4,260 calories per gram. 



Apparatus: — The apparatus used for most of the experiments 

 consisted of a cylindrical iron retort 1|" high and 1^" diameter, 

 inside measurement, having a lid which was held on by a small clamp, 

 the joint being rendered air-tight by means of an asbestos gasket. 

 A small inlet tube was screwed into the bottom of the crucible, and an 

 outlet tube into the lid; the inlet and outlet tubes being so arranged 

 that the retort could be completely immersed in an oil or lead bath. 

 For the experiments under pressure a slightly larger and heavier 

 retort was emi:)loyed, with a hexagon screw cap and rendered gas- 



