20 
SMELTING 
Although this method is a standard technique of land-based mining 
operations, it does not appear to be of commercial interest for proces- 
sing ferromanganese nodules. The problem again is one of selectivity. 
Manganese nodules contain numerous metals which smelting reduces 
to a complex alloy. Still, investigations of this method for processing 
ferromanganese nodules have been made.?? 
In the pyrometallurgical approach, the objective is to reduce selec- 
tively and collect the nickel, copper, cobalt, and molybdenum jin a 
metallic product while rejecting a major part of the manganese and 
iron in the slag. By regulating the temperature and amount of carbon 
introduced, it 1s possible to control the distribution of manganese 
between the molten iron phase and the slag. However, while the nmfetal- 
lic phase is nearly free of manganese, it contains an appreciable 
amount of iron from which it is difficult to separate the marketable 
metals. The manganese slag could be processed further into a ferro-— 
manganese product. This pyrometallurgical approach may be of in- 
terest only if an existing smelter were available, but it is not likely 
to attract new capital.?? 
21 Tbid. pp. 39-40. 
22 Tbid. p. 40. 
