Sydney atkin

Claim 1

A PROCESS FOR RECOVERING MINERAL VLUES FROM LEACHED ZONE MATERIAL DERIVED FROM PHOSPHATE ROCK OVERBURDEN AND CONTAINING SIGNIFICANT AMOUNTS OF ALUMINUM MINERAL VLUES WHICH COMPRISES HEAT TREATING SAID MATERIAL AT A TEMPERATURE ABOVE ABOUT 700 DEG. C. AND BELOW ABOUT 1000 DEG. C., REACTING THE HEAT TREATED MATERIAL WITH SULFURIC ACID AND AN AQUEOUS RECYCLE SOLUTION, ADDING TO THE RESULTING ACIDIC AQUEOUS SLURRY FLOCCULATING AMOUNTS OF A POLYELECTROLYTE LINEAR CARBON CHAIN RESIN SELECTED FROM THE GROUP CONSISTING OF PARTIALLY HYDROLYZED POLYACRYLAMIDES HAVING MOLECULAR WEIGHTS ABOVE 50,000 AND CONTAINING 70% TO 98% OF AMIDE GROUPS, PARTIALLY HYDROLYZED POLYACRYLONITRILES HAVING MOLECULAR WEIGHTS WITHIN THE RANGE OF ABOUT 50,000 TO 500,000, PARTIALLY HYDROLYZED COPOLYMERS OF ACRYLAMIDE WITH VINYL ESTERS HAVING MOLECULAR WEIGHTS ABOVE ABOUT 50,000 AND PARTIALLY HYDROLYZED COPOLYMERS OF ACRYLONITRILE WITH VINYL ESTERS HAVING MOLECULAR WEIGHTS ABOVE ABOUT 50,000, FILTERING SOLID MATERIAL FROM THE AQUEOUS SLURRY, ADDING AMMONIUM SULFATE AND SULFURIC ACID TO THE FILTRATE SOLUTION AND THEREBY CRYSTALLIZING A DOUBLE SALT OF AMMONIUM AND ALUMINUM SULFATE, FILTERING SAID CRYSTALS FROM THE SOLUTION, RECYCLING A PORTION OF THE RESIDUAL SOLUTION AS THE AFOREMENTIONED AQUEOUS RECYCLE SOLUTION, DISSOLVING A SOLUBLE CALCIUM SALT INTO THE BALANCE OF THE RESIDUAL SOLUTION AND THEREBY PRECIPITATING CALCIUM SULFATE, FILTERING SAID CALCIIUM SULFATE FROM THE SOLUTION, ADDING CALCIUM HYDROXIDE TO THE SOLUTION AND THEREBY PRECIPITATING PHOSPHORUS VALUES AS DICALCIUM PHSOPHATE, AND FILTERING SAID DICALCIUM PHOSPHATE FROM THE SOLUTION.