US 12,434,977 B2
Method for separating and purifying phosphoric acid and phosphogypsum from wet-process phosphoric acid slurry, and phosphoric acid and phosphogypsum prepared thereby
Huiquan Li, Beijing (CN); Ganyu Zhu, Beijing (CN); Ziheng Meng, Beijing (CN); and Kun Yan, Beijing (CN)
Assigned to INSTITUTE OF PROCESS ENGINEERING, CHINESE ACADEMY OF SCIENCES, Beijing (CN)
Appl. No. 18/879,352
Filed by Institute of Process Engineering, Chinese Academy of Sciences, Beijing (CN)
PCT Filed Oct. 11, 2023, PCT No. PCT/CN2023/123947
§ 371(c)(1), (2) Date Dec. 27, 2024,
PCT Pub. No. WO2024/125058, PCT Pub. Date Jun. 20, 2024.
Claims priority of application No. 202211602036.8 (CN), filed on Dec. 13, 2022.
Prior Publication US 2025/0162899 A1, May 22, 2025
Int. Cl. C01F 11/46 (2006.01)
CPC C01F 11/468 (2013.01) 19 Claims
OG exemplary drawing
 
1. A method for separating and purifying phosphoric acid and phosphogypsum from a wet-process phosphoric acid slurry, which comprises the following steps:
(1) adding an impurity-removal agent to the wet-process phosphoric acid slurry, mixing the same under the action of a micro-nano bubble external field to obtain a colloidal impurity-containing organic phase and an impurity-removed mineral slurry;
(2) subjecting the impurity-removed mineral slurry obtained in step (1) to crystallization and solid-liquid separation in sequence to obtain phosphoric acid and phosphogypsum with impurities removed;
wherein step (1) comprises:
mixing a phosphate ore with a returning acid solution, dissolving, adding a reaction acid, and then performing an acidolysis reaction to obtain the wet-process phosphoric acid
wherein the impurity-removal agent in step (1) is a phosphate ester substance, a ketone substance, a diluent, and an organic additive having phosphorus-hydroxyl;
wherein in step (1), a volume ratio of the wet-process phosphoric acid slurry to the impurity-removal agent is 1:(0.2-0.9);
and wherein in step (1), the micro-nano bubble external field is to introduce micro-nano bubbles with a size of between 10 nm to 80 μm into the wet-process phosphoric acid slurry comprising the impurity-removal agent; wherein a ratio of a volume flow rate of the micro-nano bubbles to a flow rate of the wet-process phosphoric acid slurry comprising the impurity-removal agent is 1:(15-50).