Systems and methods for recovering salts, aluminum, alumina and ammonia from salt slag waste generated in aluminum recycling

A method for recovering salts, aluminum and alumina from dry salt slag waste generated in aluminum recycling, the method comprising the steps of:

• a. removing any slag particles from a dry salt slag waste above a first pre-determined size and breaking them into particles below the first pre-determined size;
• b. separating the dry slag particles by size into two batches, the first batch being less than a second pre-determined size, the second batch being greater than the second pre-determined size;
• c. crushing the second batch of dry slag particles so that the non-metallic particles thereof are less than the second pre-determined size;
• d. removing metals from the second batch of dry slag particles, the metals comprising aluminum;
• e. scrubbing the first batch of slag and the crushed second batch of slag with water to release salt into the water;
• f. with steam and in an alumina press comprising a vent, pressing the scrubbed slag particles, resulting in alumina cake, salt effluent and ammonia gas;
• g. withdrawing the ammonia gas through the vent of the alumina press;
• h. evaporating water from the salt effluent and crystallizing the salt within the salt effluent;
• and
• i. with steam and in a salt press, pressing the crystallized salt to remove water therefrom, resulting in a potassium chloride and sodium chloride salt product, and distilled water for use in the production of steam at the alumina press and the salt press.