Overview[1]
Manganese phosphate is a white lump or amorphous powder, rarely soluble in water or alcohol, and soluble in acid; Manganese phosphate (2) has the chemical formula MnPO4·H2O and is a green-gray amorphous powder. Because Mn3+/Mn2+ has a higher potential than Li+/Li, LiMnPO4/C composite materials have the potential for high energy density. Therefore, people are paying increasing attention to lithium manganese phosphate materials.
Apply[2]
Manganese phosphate is one of the raw materials for synthesizing LiMnPO4/C composite materials. The electrical properties of the composite materials can be improved by changing the morphology and particle size of the manganese phosphate precursor.
Preparation method[2-3]
Method 1: A method for preparing manganese sulfate, manganese phosphate and calcium sulfate. The raw materials are waste liquid and manganese ore obtained from the production of titanium dioxide using the sulfuric acid method, including the following specific steps:
Step A: Grind the manganese stone into a coarse powder of 100-150 mesh, put it into the soaking tank (1) with a heating device together with the waste liquid obtained from the production of titanium dioxide by the sulfuric acid method, and soak for 8-10 hours. The soaking temperature is 60 -80℃, filter the soaking liquid through the suction filter (2) to obtain the clear filtrate and filter residue;
Step B: Add manganese hydroxide to the clarified filtrate to remove impurities, and filter to obtain a pure manganese sulfate solution;
Step C: Send the pure manganese sulfate solution into the vacuum distiller one (3) and distill it under reduced pressure into a saturated solution of manganese sulfate, cool it, and precipitate manganese sulfate crystals containing crystal water. Manganese sulfate crystals containing crystal water are precipitated. , and then washed by the washing machine one (4), the dryer one (5), and the crusher one (6) and crushed to obtain the manganese sulfate crystal product (7);
Step D: Put the pure manganese sulfate solution and calcium phosphate solution into the corrosion-resistant reactor (8) with the molar content ratio of the pure substances of manganese sulfate and calcium phosphate being 1:0.27-plasticizer price 0.4, and stir A chemical reaction is carried out under the conditions to obtain a mixture containing manganese phosphate and calcium sulfate, which is filtered through filter two (9) to obtain calcium sulfate filter cake and manganese phosphate filtrate;
Step E: Send the manganese phosphate filtrate to the vacuum distiller two (10) to be distilled into a saturated solution of manganese phosphate, and then cool and crystallize to obtain manganese phosphate hydrate. The manganese phosphate hydrate passes through the dryer two (11) and the crusher two (12) Crush to obtain manganese phosphate crystal product (13).
Method 2; a new method for the synthesis of manganese phosphate, including the following steps:
(1) Preparation of manganese acetate: Add 500kg of electrolytic manganese into a 500L glass-lined reaction kettle, introduce inert gas nitrogen, replace the air in the reaction kettle, and make the explosion limit of hydrogen lower than 4.1%. Then add 99% acetic acid solution of red phosphorus flame retardant, seal the reaction, and release hydrogen gas after the reaction is completed to obtain manganese acetate;
(2) Synthesis of manganese phosphate: Heat the reaction kettle in step (1) to 70°C, stir, and add 85% phosphoric acid to obtain manganese phosphate;
(3) Separation and drying of manganese phosphate: Spray dry or vacuum concentrate the manganese phosphate solution in step (2), and control the evaporation time to 3 hours; evaporate the acetic acid solution and recycle it for use Preparation of manganese acetate;
(4) Packaging of manganese phosphate: The dried manganese phosphate is ground and pulverized, then packaged and stored in storage.
The process is simple, the measurement is accurate, there are no three wastes, and the operating cost is low.
Main reference materials
[1] Ferroalloy Dictionary
[2] CN201810622822.1 A new method for the synthesis of manganese phosphate
[3] CN201010598176.3 A method for preparing manganese sulfate, manganese phosphate and calcium sulfate
