22 



wells: fractional precipitation 



precipitated by sodium carbonate enough for one metal only. 

 After a time an aliquot portion of the mother liquor was analyzed 

 and thus the composition of the precipitate determined by differ- 

 ence. 



Since the experiments were intended to apply to the chemistry 

 of ore deposition it was desired to find out the final effect. It was 

 shown by some of the earlier results that the immediate action 

 consists in a precipitation of both metals in nearly equivalent 

 quantities, and that one of them proceeds to dissolve, the other 



TABLE I 



Fractional Precipitations 



EXPERIMENT 



TAKEN, MILLI-EQ. PES LITER 



4.. 



5.. 



6.. 



7. 



8. 

 22. 

 23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 

 31. 

 32. 

 33. 

 34. 

 39. 

 40. 

 41. 

 42. 

 60. 

 64. 

 71. 

 74. 

 78. 



8 ZnS0 4 



20 CdS0 4 



10 FeS0 4 



10 CuS0 4 

 8 C11SO4 

 8 Pb(N0 3 ) 2 

 8 Pb(N0 3 ) 2 

 8 Zn(N0 3 , 2 

 8 AgN0 3 

 8 AgN0 3 

 8 Z11SO4 

 8 AgN0 3 

 8 FeS0 4 

 8 FeS0 4 

 8 Cd(N0 3 ) 2 

 8 MnS0 4 

 8 NiS0 4 

 8 NiS0 4 

 8 AgN0 3 



8 CaS0 4 

 20 ZnS0 4 

 10 CaS0 4 

 10 FeS0 4 



8 ZnS0 4 

 8 AgN0 3 

 8 Cd(N0 3 ) 2 

 8 Pb(N0 3 ) 2 

 8 HgNOa 

 8 Cd(NO,) 2 

 8 NiS0 4 

 8 Zn(N0 3 ) 2 

 8 NiS0 4 

 8 Zn(N0 3 ) 2 

 8 HgN0 3 

 8 CaS0 4 

 14.54 MgS0 4 

 8 MnS0 4 

 8 MnS0 4 



DURATION OF 

 EXPERIMENT 



FOUND IN PRECIPITATE 



days 



17 

 19 



3 



2 

 26 



4 



6 



6 

 24 



4 

 10 



8 



1 



1 

 11 



2 



5 



9 



7 



7 

 8 

 8 

 6 

 18 hrs. 

 1 hr. 

 15 



tr. Ca 



4.5 Zn 

 tr. Ca 



5.35 Fe 

 0.76 Zn 

 0.08 Ag 

 0.42 Cd 

 tr. Zn 

 7.98 Hg 

 7.18 Cd 

 1.50 Ni 

 3.96 Zn 



3.06 Ni 

 2.64 Zn 



7.36 Hg 

 1.64 Ca 

 tr. Mg 

 3.80 Mn 

 5.76 Mn 



1.56 Ca 

 1.12 Mg 

 0.20 Cd 

 2.96 Ag 

 8.96 Mn 

 5.70 Ca 

 2.34 Cd 



