Richards, Robert H.  1844-1945. <br/><br/>
Ore dressing /  
Robert H. Richards 
 - 2st ed.  
 - New York :   The Engineering and mining journal,   1909. 
 - 4 v. :   illus., diagrs.   24 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>MINERALES <br/>TRATAMIENTO DE MINERALES
<br/><br/><label>Universal Decimal Class. No.: </label>622.7