The microflotation of silica / 
United States, Department of Interior 
 - Washington, D.C. :  The Department,  1972 
 - 26 p. ;  26 cm. 
<br/><br/> Report no. 756 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Acid mine drainage<br/>Coal mine waste<br/>Manufacturing wastes--Prevention
<br/><br/><label>Dewey Class. No.: </label>628.1683