Manufacture of cation exchange

Claim 1

IN THE PRODUCTION OF CATION EXCHANGE MATERIAL FROM COAL BY A PROCESS WHICH COMPRISES HEATING, IN A MEDIUM OF A FREE OXYGEN-CONTAINING GAS AND AT A TEMPERATURE WITHIN THE RANGE OF FROM 220* TO 350% C. SAID COAL WHICH IS OXIDIZABLE BUT NOT COMPLETELY DECOMPOSABLE UNDER THE CONDITIONS EMPLOYED AND WHICH IS OF ABOUT 0.2 TO 1 MM. PARTICLE SIZE, CONTINUING SAID HETING UNTIL SAID MATERIAL IS OXIDIZED, SUBSEQUENTLY HYDROLYZING THE OXIDIZED PRODUCT BY TREATMENT THEREOF WITH A HOT AQUEOUS STRONGLY ALKALINE SOLUTION AND THEREAFTER SEPARATING THE HYDROLYZED PRODUCT FROM SAID SOLUTION, THE TIME OF HEATING THE INITIAL COAL BEING SUCH THAT THE PARTICLE SIZE OF THE CATION EXCHANGER IS SUBSTANTIALLY THE SAME GRAIN SIZE AS THAT OF THE STARTING MATERIAL, THE IMPROVEMENT WHEREBY CATION EXCHANGERS OF INCREASED CAPACITY BY VOLUME ARE OBTAINED WHICH COMPRISES IMMERSING SAID CATION EXCHANGER IN SOLID FORM IN AN ACID WHICH IS NON-OXIDIZING AND NON-WATER ADSORBING UNDER CONDITIONS OF USE AND IS OF SUFFICIENT STRENGTH TO DECREASE THE VOLUME OF SAID SOLID EXCHANGER AND CONTINUING SAID TREATMENT UNTIL THE VOLUME OF SAID EXCHANGE MATERIAL HAS BEEN DECREASED BY ABOUT 15% TO 25%.