Systems and methods for reducing formation of scale in phosphoric acid production

A method for reducing formation of scale in phosphoric acid production, wherein a phosphate-containing ore is combined with an acid to form an acidic slurry and the acidic slurry is processed to form an acidic stream, the method comprising:

• providing a scale inhibitor comprising;
• sodium poly(phosphate) according to formula (II),
• Nan+2PnO3n+1 (II)
• wherein n is an integer having a value of 21, and
• at least one of;
• an additional organic phosphonate comprising bis(hexamethylene triamine penta (methylene phosphonic acid)), hexamethylenediaminetetra (methylene phosphonic acid), diethylene triamine pentamethylene phosphonic acid, 1-hydroxyethane 1,1-diphosphonic acid, or combinations thereof, and
• an inorganic phosphate comprising tetrasodium pyrophosphate;
• and
• combining the scale inhibitor and at least one of the phosphate-containing ore, the acidic slurry, and the acidic stream, to reduce the formation of scale.

A system for phosphoric acid production exhibiting a reduced formation of scale, the system comprising:

• a substrate having a surface in contact with at least one of a phosphate-containing ore, an acidic slurry formed from the phosphate-containing ore and an acid, and an acidic stream formed from the acidic slurry;
• and
• a scale inhibitor comprising;
• an inorganic phosphate according to formula (I),
• (XPO3)m (I)
• wherein X is Na, K, H, or combinations thereof, and m is an integer having a value of at least 6,
• an inorganic phosphate according to formula (II),
• Yn+2PnO3n+1 (II)
• wherein Y is Na, K, H, or combinations thereof, and n is an integer having a value of at least 6, or
• a combination thereof;
• wherein the system comprising the scale inhibitor exhibits a reduced formation of scale on the surface as compared to a system free of the scale inhibitor.