&penments made on a Sample of Pig Iron. 43 



Art. XIII. — Experiments made on a Sample of Pig Iron 

 received from the British and Tasmcmian Iron Com- 

 pany, Port Lempriere, Tasmania. 



By J. Cosmo Newbery and Frederic Dunn. 



[Read 12th December, 1878.] 



During the month of November, 1876, a sample of pig iron 

 was sent to the laboratory for examination and report. 

 Upon treating a portion of this iron (which had been very 

 finely ground) in a flask and boiling on the sand-bath with 

 nitrohydrochloric acid (IJ parts of hydrochloric to 1 of 

 nitric acid) the iron was readily attacked. When aU action 

 had ceased the supernatant liquor was carefully decanted off 

 from the residue. The latter was found to have a peculiar 

 bronze-like appearance. This powder was at first believed to 

 be " nitride of titanium," but upon further investigation 

 was found to be a compound of chromium iron and car- 

 bonaceous matter. 



The pig iron which was found to contain the most chro- 

 mium was coarse-grained and crystalline, having a white 

 lustre somewhat resembling " spiegeleisen" in appearance, 

 but its lustre was of a less brilliant white colour, and the 

 crystal plates very rough. 



This sample gave a residue on treatment with nitro- 

 hydrochloric acid of 9 '38 per cent, of a bronze-coloured 

 chromium compound (calculated to the total pig), whereas a 

 sample of pig iron which was of much finer grain and 

 granular in structure gave 1'52 per cent, of the same 

 peculiar compound. 



The pig iron when treated with hydrochloric and sul- 

 phuric acids gave difierent results to that obtained by 

 nitric acid. 



Treatment with Hydrochloric Acid. 

 The pig iron was broken up into pieces about the size of 

 a bean, placed in a flask, and boiled with hydrochloric acid. 

 After all eflervescence had ceased the vessel was taken ofl^ 

 the sand-bath and transferred to a quiet place, in order that 

 the small particles might settle at the bottom. The super- 

 natant liquor was then decanted ofl',the residue was re-treated 



