A Brief Description of Iron Phosphate Production Process

Lithium-ion batteries and ternary batteries currently represent most widely-used new energy batteries. Each of these two types of batteries has its own comparative advantages and disadvantages. Iron phosphate is the key to the production of high quality lithium ion batteries. The following is a brief overview of the production process of iron phosphate.

At present, the mainstream iron phosphate production routes are ammonium process (ferrous sulfate + monoammonium phosphate) and sodium process, also known as phosphoric acid process (phosphate + liquid alkali + ferrous sulfate). They are mainly distinguished by the use of different pH regulators. Ammonium process adopts ammonia, while sodium process adopts sodium hydroxide:

1. Ammonium process: ferrous sulfate solution reacts with monoammonium phosphate, and then the excess acid is neutralized by ammonia water after precipitation and filtration, and finally to obtain iron phosphate.

2. Sodium process: Iron(II) sulfate (after phosphoric acid acidification) reacts with hydrogen peroxide to generate ferric dihydrogen phosphate, and then adjust the pH value to about 2 with sodium hydroxide solution to generate Iron(III) phosphate.

3. In addition to the above two mainstream processes, there is another popular process recently, which is the phosphoric acid + iron powder process, although its raw material is relatively expensive, however, due to its low discharge of wastewater (mainly hydrogen gas), the environmental protection pressure is small. Therefore, at present, more and more enterprises in the phosphorus chemical industry would like to adopt this process.

From the perspective of product stability analysis, ammonium process and sodium process have better stability, while the current phosphoric acid + iron powder process has relatively poor stability.

From the perspective of cost analysis, the ammonium process has the lowest cost, currently CNY 6000-7000 per ton cheaper than the sodium process (phosphoric acid process). In addition, the ammonium process yields ammonium sulfate as a by-product. This represents one further benefit. 

As the cost of phosphorus accounts for more than 53% of the production cost of iron phosphate, leading enterprises of integrated phosphorus chemical industry will benefit from raw material self-sufficiency and technological advantages as compared with titanium dioxide and lithium battery enterprises. 

Myande Group has rich experience in the treatment of ammonium sulfate wastewater in the production process of iron phosphate, and can recycle and sell the byproduct ammonium sulfate produced in the ammonium process through evaporating concentration, evaporating crystallization and flash separation, effectively increasing the added value of the ammonium process of Iron (III) phosphate.