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U.S. Department of Energy
Office of Scientific and Technical Information

Filtering material and process of preparing the same

Patent ·
OSTI ID:7280386
A process of preparing a filtering compound from a porous spent shale of a silicious nature is described. The shale is heated with a strong caustic soda solution whereby the caustic soda enters the pores of the shale and forms sodium silicate with the silica in the pores. Sulfuric acid is added to set free silicic acid in the pores, and the shale is washed with water until free from sodium sulfate, then heated to a low red heat until dry.
Assignee:
TIC; EDB-78-013738
Patent Number(s):
US 1555639
OSTI ID:
7280386
Country of Publication:
United States
Language:
English