46 Experiments made on a Sample of Pig Iron 



The filtrate from these plates was tested to see if any 

 chromium had gone into solution ; only a slight reaction was 

 obtained. 



The bronze powder upon treating with sulphuric acid and 

 boiling is readily attacked, carbonaceous particles being 

 liberated ; the continued action of the sulphuric acid on the 

 latter causes the evolution of foetid hydrogen, the solution 

 assuming a brownish black appearance, which upon further 

 boiling assumes a green colour. 



Hydrochloric acid dissolves this powder, but the peculiar 

 bronzy appearance remains to the last. The solution is of 

 a fine emerald green colour ; carbonaceous particles separate 

 during the solution ; a peculiar hydrocarbon smell is evolved. 



Acetic acid fails to dissolve this bronze powder, and is 

 therefore useful in separating any free iron which may be 

 mechanically mixed with it. 



A portion of the powder was ground in an agate mortar 

 with water ; it loses its bronze-like appearance, becoming 

 steel-grey, carbonaceous matter being liberated (this shows 

 that the carbonaceous matter is merely mechanically dis- 

 seminated), the non-magnetic, metallic particles being left 

 behind. 



Upon analysis the bronze powder was found to contain in 

 100 parts: — 



Percentage of iron ... ... ... ... 81'12 



„ chromium ... ... ... 15'09 



„ carbonaceous matter ... 4"11 



„ silica 0.53 



100-85 



The analysis shows that when separated from the carbon 

 it has the same composition as the nitric acid residue. The 

 following is its composition, after deducting the carbon and 

 silica : — 



Percentage of iron ... ... ... ... 84'32 



„ chromium ... ... ... 15*68 



10000 

 Teeatment with Acetic Acid. 



100 grains of finely-ground pig iron were placed in a flask 

 and gently boiled with acetic acid. 



