Copper recofery process

Claim 1

IN A PROCESS OF PRODUCING METALLIC COPPER, THE STEPS WHICH COMPRISE; LEACHING A COPPER ORE WITH SULFURIC ACID SOLUTION TO PRODUCE A PREGNANT SOLUTION CONTAINING COPPER SULFATE AND SULFURIC ACID; CLEANING IRON SCRAP CONTAINING DIRT AND RUST BY SUBJECTING IT TO VIGOROUS AGITATION IN CONTACT WITH A DILUTE SULFURIC ACID SOLUTION TO REMOVE ADHERING DIRT AND DISSOLVE RUST AND FERROUS SULFATE; SEPARATING THE RESULTING ACIDIC FERROUS SULFATE SOLUTION AND THE REMOVED DIRT FROM THE CLEANED IRON; PASSING SAID ACIDIC FERROUS SULFATE SOLUTION DOWNWARDLY THROUGH AND IN CONTACT WITH A PERMEABLE HEAP OF BROKEN ROCK EXPOSED TO THE AIR TO REMOVE IRON FROM THE SOLUTION BY PRECIPITATION AS FERRIC HYDROXIDE AND TO PRODUCE SULFURIC ACID IN THE SOLUTION, BY REACTIONS INVOLVING OXIDATION AND HYDROLYSIS, WHILE MAINTAINING A RELATIVELY LOW ACIDITY IN THE SOLUTION IN CONTACT WITH SAID HEAP SO AS TO PROMOTE SAID REACTIONS AND THE REMOVAL OF IRON FROM THE SOLUTION; ADDING THE EFFLUENT SOLUTION FROM THE LAST-MENTIONED STEP, DEPLETED IN IRON AND CONTAINING SULFURIC ACID, TO THE SULFURIC ACID SOLUTION IN THE LEACHING STEP, WHILE MAINTAINING IN THE SOLUTION DURING SAID LEACHING STEP AN ACIDITY HIGHER THAN THAT IN THE SOLUTION IN CONTACT WITH SAID HEAP AND SUFFICIENT TO PREVENT PRECIPITATION OF FERRIC HYDROXIDE; SUBJECTING THE CLEANED IRON TO CONTACT WITH THE PREGNANT SOLUTION FROM THE LEACHING STEP TO PRECIPITATE