m 

 ORE AND FUEL 



Sulphur.* — To £ gram of ore add 10 cc. chlorate mixture and 

 evaporate to dryness. Take up in 10 cc. HC1 and 10 cc. water and 

 boil. Filter off the silica, boil the filtrate, and add solution of 

 barium chloride (£ gram barium chloride to each determination), 

 allow to settle, filter, washing thoroughly with hot water, remove 

 filter, burn in the muffle and weigh — the weight x .13734 = $ S. 



Ores. — On ores, silica, iron, and lime are generally determined 

 on one weighing, viz. : To £ gram of ore add 15 cc. HC1 and 10 cc. 

 nitric acid and evaporate to dryness, in a beaker. Take up in 10 cc. 

 HC1 and 20 cc. water, boil and filter; burn and weigh the silica. 

 To the filtrate add ammonia to ppt. the Fe, boil a few minutes and 

 filter. To the filtrate add ammonium oxalate, boil, and filter off 

 the lime, as calcium oxalate. 



The Fe on the filter is now dissolved in HC1, warmed, reduced 

 with SnCl 2 , etc., and treated as in Fe in slag. 



The ammonium oxalate is now proceeded with as in lime 

 in slag. 



Zinc. — Zinc in ores is treated essentially as in slag, by a modi- 

 fication of Low's method.f 



Manganese. — Essentially as in slags. Often, however, it is 

 only necessary to boil the ore with HOI. 



Copper and Lead. — To 1 gram of ore add 15 cc. HC1 and boil 

 a few minutes. Now add 15 cc. nitric and 10 cc. sulphuric acids and 

 boil until all S0 3 fumes cease. Cool, take up in 30 cc. water and 

 boil to take up all soluble sulphates. Filter; the lead will then 

 be on the filter and the Cu will be in the filtrate. 



Cu. — Place in the filtrate a small piece of aluminum (1^ inches 



* In practice the sulphurs are weighed out and started at the same time as the slag. 



t Cadmium may be removed when necessary by passing H 2 S through the acid solution be- 

 fore adding the test lead. CdS and CuS are then ppted. together and must be filtered 

 out. The solution is then ready for titration, the addition of test lead being now un- 

 necessary. The BUS will not interfere. 



