﻿Segregation in Ores and Mattes. 



179 





A. 



B. 



C. 



D. 



E. 



Copper . , 



..25.00 



25.62 



25.02 



20.80 



24.46 



Nickel... 



...20.2 



20.9 



20.5 



21.60 



20.20 



Iron 



...29.4 



27.3 



28.8 



35.5 



31.5 



These analyses show that copper tends toward the top 

 and outside of the casting, while nickel and iron tend 

 to concentrate toward the centre. 



A half pot was now selected in which radial cracks 

 seemed to show the centre of segregation. Small portions 

 were broken off at the points indicated and analyzed 

 as follows : 



Fig. 2. 



A. 



B. 



D. 



Copper 24.46 23.68 22.46 22.80 



Nickle 18.02 19.06 19.16 18.74 



Iron 31.0 31.5 31.5 32.00 



These samples showed as before the upward and 

 outward tendency of copper, but did not so clearly show 

 the inward tendency of nickel. The reason was found to 

 lie in the manner of sampling, as it was found almost 

 impossible to break with a hammer the sample desired, at 

 the exact point in question. In order to get a correct 

 sample, and to map out, if possible the variations of 

 copper and nickel, a quarter pot was placed under a drill 

 and sampled as indicated in the following sketch by 

 drilling with an inch drill holes one half inch deep at the 

 points marked. These samples were then carefully 

 analyzed, and as they were entirely free from slag, 

 the sulphur was in each case taken as the difference 

 between the sum of copper nickel and iron and 100 

 per cent, which has been found to be very nearly the 

 correct amount. 



The entire quarter pot was now crushed, quartered, 

 sampled and analyzed. 



