STUDIES OF THE WHITE CLAY IN THE SOUTH KYUSHU : REPORT 15. ON THE SULFURIC AND TRAETMENT OF THE CLAY IN THE AUTOCLAVE

The sulfuric acid treatment of montmorillonite clay has long been used and its treatment has been utilized industrially in many ways. On the other hand few reports of the sulfuric acid treatment of kaolinite clay have been published, and the application of the clay other than common ceramic materials is quite unknown. The author has discoverd various interesting characters of the amorphous particle hydrohalloysite by using sulfuic acid. The colored clay, which has not been in use, may be used as industrial material satisfactorily by IN･H_2SO_4, 10atm., 5hrs treatment. Because by this treatment the white-degree of the clay is high by nearlly 20 compared with that of the untreated clay. Then if treated by condensed sulfurie acid, the BAS (basic aluminum sulfate) is easily produced in the clay and the clay structure mostly collapses, and Al_2O_3 in the clay is extracted as the BAS and Al_2(SO_4)_3. Therefore the utilization of hydrohalloysite as Al_2O_3 material can well be considered