Process for recovering feed products from animal manure

A process for extracting feed products from animal manure, comprising:

• forming a manure-water slurry of between 70% and 80% moisture content in a first pit and permitting said slurry to ferment to convert non-protein nitrogen to true protein;
• forcing said slurry under pressure against a screen to thereby separate said slurry into solid and liquid fractions;
• washing said solid fraction as it is conveyed to a press to provide a silage-like component of undigested fibers and grains;
• separating relatively dense indigestible minerals and fiber particles from high protein nutrients in the liquid fraction,
• adding an acid to the remaining liquid fraction to cause nitrogenous compounds to form salts which are less volatile than said compounds, and
• thereafter heating said liquid fraction to evaporate a substantial amount of the water in said liquid fraction and thereby yield a high protein feed supplement containing relatively low amounts of indigestible minerals and fiber particles.

A process for recovering feed products from animal manure, comprising

• forming a manure-water slurry in a first pit and agitating said slurry while allowing debris to settle to the bottom of said pit for periodic removal of the debris;
• transferring said slurry to a second pit and permitting said slurry to ferment in said second pit until its pH is about 5 or less;
• pressing said fermented slurry against a screen to separate said slurry into liquid and solid fractions;
• washing said solid fraction with fresh water and recycling the excess wash water to said first pit to maintain a preselected moisture content in said slurry;
• separating insoluble minerals and indigestible fiber particles from high protein nutrients in said liquid fraction;
• adding acid to the remaining portion of said liquid fraction containing said high protein nutrients to cause nitrogenous compounds in said liquid fraction to form salts which are less volatile than said nitrogenous compounds;
• and
• evaporating water in said liquid fraction to yield a high protein feed supplement containing relatively low amounts of indigestible minerals and fibers.