Process for making a soil fertilizing and soil buffering product

Claim 1

A PROCESS FOR MAKING A SOIL FERTILIZING AND SOIL BUFFERING PRODUCT WHICH COMPRISES: INTERMIXING CONCENTRATED ORTHOPHOSPHORIC ACID WITH A SLAG OBTAINED FROM THE PROCESS OF REFINING HIGH IRON CONTENT COPPER ORES IN A REVERBERATORY FURNACE, SAID INTERMIXING BEING AFFECTED IN THE ABSENCE OF ANY EXTRANEOUS ADDITIONAL WATER OTHER THAN THE WATER PRESENT IN SAID ACID, AND THE WEIGHT RATIO OF SLAG TO ACID IS BETWEEN 3 AND 6 PARTS BY WEIGHT OF ACID FOR EACH 5 PARTS BY WEIGHT OF SLAG AND THE CONCENTRATION OF THE ORTHOPHSPHORIC ACID IS BETWEEN 75% AND 85.8%; AND PROMPTLY THEREAFTER, AFTER THE INITIAL REACTION BETWEEN THE ACID AND SLAG, HEATING THE INITIALLY REACTED MATERIALS TO A TEMPERATURE BETWEEN 300*F. AND ABOUT 650*F. AND BELOW THE SINTERING TEMPERATURE OF SAID MATERIALS AND MAINTAINING SAID MATERIALS AT SAID TEMPERATURE FOR A TIME SUFFICIENT FOR ALL OF THE SULFUR PRESENT TO BE ELIMINATED FROMS SAID HEATED INITIALLY REACTED MATERIALS AS SULFUR DIOXIDE AND RECOVERING THE RESULTING SOIL FERTILIZING AND SOIL BUFFERING REACTION PRODUCT FROM WHICH THE SULFUR HAS BEEN EXPELLED AS SULFUR DIOXIDE AND IN WHICH THE IRON IN THE MIXTURE HAS BEEN CONVERTED INTO FERROUS ORTHOPHOSPHATE.