Last article have introduced the mainly LFP cathode manufacturing process in China. If a company wants to go upstream to produce the key raw materials like LFP cathode precursor which is anhydrous iron phosphate, you could see through this post. First we are going to introduce and compare several synthesis methods of FP anhydrous iron phosphate manufacturing process. Then goes to how to synthesize LFP precursor FP anhydrous iron phosphate.
Synthesize method | Process advantages | Process drawbacks |
Iron dissolving in sulfuric acid | 1. Abundant sources of raw materials, subject to market fluctuations small | 1. High production cost. 2. The production process generates a large amount of hydrogen gas, poor safety 3. Requires a large amount of sulfuric acid and other easily toxic chemical reagents, subject to strict control. |
Iron dissolving in phosphoric acid | 1. Abundant sources of raw materials, subject to market fluctuations are small 2. More than 90% of the wastewater generated in the production process can be recycled, basically no by-products generated 3. There is no titanium and other impurities in the iron raw materials, and the amount of solid waste generated is small. | 1. High production cost. 2. Large amount of hydrogen gas is produced in the production process, poor safety 3. The dissolution of iron is slow and difficult to control, need to use 100 mesh iron powder or a large number of dissolving pools to dissolve in advance |
FeSO4+NaOH | 1. Iron raw materials are mainly titanium dioxide by-products of ferrous sulfate heptahydrate, cheap, iron phosphate production cost of the lowest program. 2. The production process is relatively simple, no difficult to dissolve and so on. 3. The production process is safe and stable, the product fluctuation is small. 4. no irritating odor in the production process, relatively environmentally friendly. | 1. Iron raw materials need to be decontaminated and purified first, generating a large amount of solid waste (1/3 of titanium phosphate and other titanium slag). 2. The production process produces a large number of by-products anhydrous sodium sulfate, need to be on the MVR and other responsive environmental protection equipment. 3. The value of the by-product sodium sulfate produced is relatively low. |
FeSO4+NH4OH | 1. iron raw materials mainly titanium dioxide byproduct ferrous sulfate heptahydrate, cheap. 2. The production process is relatively simple, there is no difficult to dissolve and so on. 3. The production process is safe and stable, and the product fluctuation is small. 4. Produced by-product ammonium sulfate value is slightly higher, there is a certain sales value | 1. The iron raw material needs to be decontaminated and purified first, which produces a large amount of solid waste (1/3 of titanium phosphate and other titanium slag). 2. The production process produces a large number of by-products of ammonium sulfate, which needs to be on MVR and other responsive environmental protection equipment. 3. The production process, there are irritating ammonia gas generated in various locations, need to be on a relatively large number of environmental protection equipment (odor collection). |
Beyond the above several anhydrous iron phosphate method , the most friendly to the environment is the second one but the cost is a little bit higher than the ammonia/sodium method. The flow chart process as below
The mainstream one also the lowest cost one is the ammonia/sodium(FeSO4+NaOH)、（FeSO4+NH4OH） method. The flow diagram is below
To sum it up, using which process to produce FP is up to your local environment regulations and the budget call. If you intend to install this line for mataching your current LFP cathode plant production, please contact us for detailed equipments quote.