Organic dispersing agent for preparing phosphoric acid from phosphate ore as well as preparation method and use method of organic dispersing agent

Abstract

The invention discloses an organic dispersant for preparing phosphoric acid from phosphate ore and a preparation method and a use method thereof. Relates to the technical field of mineral processing. The adhesive is prepared from acrylamide, dimethylacrylammonium chloride, a surfactant, an initiator and water, the initiator is a compound of 2.2 '-azo (2-amidino propane) dihydroxide, dimethyl carbonate and potassium peroxodisulfate. The organic dispersing agent contains specific components and the compound initiator, the recovery rate of phosphoric acid can be remarkably increased and reaches 94% or above, the water content of minerals is reduced, and the operation and transportation cost is reduced.

Description

Technical Field

[0001] This application relates to the field of mineral processing technology, specifically to an organic dispersant for preparing phosphoric acid from phosphate rock, and its preparation and application methods. Background Technology

[0002] Organic dispersants are cationic polymers containing strong ionic groups and active adsorption groups. They are easily soluble in water, have strong coagulation power, good hydrolytic stability, and are not sensitive to pH changes. When used, they require a small dosage, produce large flocs, have a fast settling rate, and low residual turbidity.

[0003] When existing organic dispersants are used in the wet-process phosphoric acid production of phosphate rock in the semi- and secondary beneficiation stages, significant drawbacks remain. Specifically, these dispersants exhibit weak bonding with phosphate rock particles, resulting in poor dispersion. Furthermore, they suffer from poor stability during use, consequently affecting acidolysis efficiency and product quality. Moreover, they fail to improve the dewatering effect of filter presses, easily causing mineral powder to adhere to the conveyor belt or the filter belt of the plate and frame filter press, reducing phosphoric acid recovery and increasing production costs. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, this application provides an organic dispersant for preparing phosphoric acid from phosphate rock, and its preparation method and usage method.

[0005] This application adopts the following technical solution: an organic dispersant for preparing phosphoric acid from phosphate rock, comprising acrylamide, dimethylpropene ammonium chloride, surfactant, initiator and water; wherein the initiator is a compound of 2,2'-azo(2-amidinylpropane) dihydroxide, dimethyl carbonate and potassium persulfate.

[0006] Optionally, the mass ratio of the 2,2'-azo(2-amidinylpropane) dihydroxyl, dimethyl carbonate, and potassium persulfate is 1:0.5:1.

[0007] Optionally, the acrylamide has a mass fraction of 0.5% to 0.8%.

[0008] Optionally, the organic dispersant further comprises a chelating agent EDTA, wherein the mass fraction of EDTA is 0.1% to 0.2%.

[0009] Optionally, the surfactant is a nonionic or anionic surfactant.

[0010] Optionally, the mass ratio of dimethylpropene ammonium chloride to acrylamide is greater than 20:1.

[0011] A method for preparing an organic dispersant for phosphoric acid production from phosphate rock includes the following steps: mixing acrylamide, dimethylpropene ammonium chloride, surfactant, initiator and water uniformly, and generating an organic dispersant through an initiation reaction.

[0012] Optionally, the initiator addition step includes adding 2,2'-azo(2-amidinylpropane) dihydroxyl, dimethyl carbonate and potassium persulfate in a mass ratio of 1:0.5:1 to the reaction system.

[0013] Optionally, the initiation reaction is carried out under the protection of an inert gas, and the reaction temperature of the initiation reaction is higher than the ambient temperature but lower than 50°C.

[0014] A method for preparing an organic dispersant for phosphoric acid using phosphate rock involves diluting the organic dispersant to 0.1%-1% before use, and then placing the diluted organic dispersant into a phosphate rock slurry tank located 10m in front of a plate and frame filter press, allowing it to be fully mixed with the phosphate rock slurry by means of the flow rate.

[0015] In summary, this application includes at least one of the following beneficial technical effects:

[0016] 1. Organic dispersants containing specific components and compound initiators significantly improve the recovery rate of phosphoric acid, reaching over 94%;

[0017] 2. Organic dispersants enhance stability and binding force with phosphate rock, thereby improving the dewatering effect of phosphate rock slurry through plate and frame filter press, thus increasing production efficiency and reducing operating costs. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be described in further detail below. The described embodiments are only possible technical implementations of the present invention, but are not limited thereto. Those skilled in the art can combine the embodiments of the present invention to obtain other embodiments without creative effort, which are also within the protection scope of the present invention.

[0019] This application mainly uses a variety of components in a specific ratio to prepare an organic dispersant, which achieves the effect of improving the extraction rate and purity of phosphoric acid and enhancing the stability of the dispersant. The following is a further detailed description of this application.

[0020] Example 1

[0021] The organic dispersant for preparing phosphoric acid from phosphate rock provided in this application includes acrylamide, dimethylpropene ammonium chloride, surfactant, initiator and water. These components work together to form an organic dispersant with good dispersing properties, which can enhance the binding force with phosphate rock, improve the dispersion effect, stabilize the acid hydrolysis process, and ultimately improve the extraction rate and product quality of phosphoric acid.

[0022] Specifically, acrylamide is an important component of organic dispersants. It typically appears as a white crystalline powder, is chemically reactive, and has some water solubility. Commercially available acrylamide products generally have high purity, meeting the preparation requirements of this dispersant. Of course, acrylamide is also available in other forms, such as granules. It can interact with the surface of phosphate rock, enhancing the bonding between the dispersant and the phosphate rock. In this example, the mass fraction of acrylamide is 0.5%. Dimethylpropene ammonium chloride is a colorless, transparent liquid with good cationic properties. It can adsorb onto the surface of phosphate rock particles, altering the surface charge properties of the particles, which is beneficial for better dispersion of the phosphate rock by the dispersant. Dimethylpropene ammonium chloride solutions of different concentrations are available on the market, and can be selected according to actual needs. In this example, the mass ratio of dimethylpropene ammonium chloride to acrylamide is greater than 20:1. The two work together synergistically, allowing the dispersant to adhere more effectively to the phosphate rock particles, preventing particle agglomeration, and thus improving the dispersion effect.

[0023] Surfactants reduce the surface tension of a solution, allowing dispersants to spread better on the phosphate rock surface. Nonionic surfactants, such as fatty alcohol polyoxyethylene ethers, are liquids with good emulsifying and dispersing properties and are environmentally friendly; anionic surfactants, such as sodium dodecylbenzene sulfonate, are white or pale yellow powders with strong detergency and dispersing abilities. Different types of surfactants can be selected based on the specific properties of the phosphate rock and the acidolysis conditions. They work in combination with other components to promote the uniform distribution of the dispersant in the phosphate rock acidolysis system.

[0024] The initiator is a compound of 2,2'-azo(2-amidinylpropane) dihydroxyl, dimethyl carbonate, and potassium persulfate. 2,2'-azo(2-amidinylpropane) dihydroxyl is a white or pale yellow powder, dimethyl carbonate is a transparent liquid, and potassium persulfate is a colorless or white crystal. The three are compounded in a mass ratio of 1:0.5:1, which can initiate polymerization under suitable conditions, causing acrylamide and dimethylpropene ammonium chloride, among other components, to polymerize and form a high molecular weight polymer, thus enhancing the stability and activity of the dispersant. This compounding method combines the advantages of the three initiators, allowing them to function well under different temperatures and reaction environments, improving the performance of the organic dispersant. Water serves as the solvent for the entire system, providing a medium for the dissolution and reaction of other components, ensuring thorough mixing and reaction of all components.

[0025] The implementation principle of this embodiment is as follows: by mixing acrylamide, dimethylpropene ammonium chloride, surfactant, initiator, and water in a certain proportion, a polymerization reaction is initiated by the initiator to form an organic dispersant with specific structure and properties. This dispersant improves the binding force and dispersion stability with phosphate rock through the combination of acrylamide and dimethylpropene ammonium chloride with the phosphate rock, and the auxiliary effect of the surfactant. Simultaneously, the compounded initiator ensures the smooth progress of the reaction, giving the dispersant good activity and stability, thereby significantly improving the extraction rate of phosphoric acid and product quality, representing a significant improvement and enhancement compared to existing technologies.

[0026] Example 2

[0027] The difference between this embodiment and the previous embodiment is that the mass fraction of acrylamide in the organic dispersant is 0.6%. At this content, acrylamide can ensure sufficient binding force with phosphate rock and better synergistic effect with other components. It coordinates with components such as dimethylpropene ammonium chloride and surfactants, enabling the organic dispersant to more effectively disperse phosphate rock during the acid hydrolysis process, further improving the extraction rate of phosphoric acid.

[0028] The implementation principle of this embodiment is as follows: By rationally adjusting the mass fraction of acrylamide, its function in the organic dispersant is optimized. Through synergistic effects with other components, acrylamide at this mass fraction enhances the binding force between the dispersant and phosphate rock, promoting the adsorption and dispersion of the dispersant on the phosphate rock surface, thereby improving acidolysis efficiency and phosphoric acid extraction rate. This precise mass fraction control avoids the adverse effects caused by improper content and, compared to existing technologies, better meets the needs of actual production.

[0029] Example 3

[0030] The difference between this embodiment and the previous embodiment is that the organic dispersant contains 0.8% acrylamide by mass and also includes 0.2% EDTA as a chelating agent by mass. EDTA can chelate with metal ions during acidolysis to form stable complexes. During the acidolysis of phosphate rock, some metal ion impurities may exist, which could trigger side reactions and reduce the purity of phosphoric acid. Adding 0.2% EDTA effectively captures these metal ions and inhibits side reactions. Simultaneously, with an acrylamide mass fraction of 0.8%, its synergistic effect with other components further improves the extraction rate of phosphoric acid while ensuring effective dispersion.

[0031] The implementation principle of this embodiment is as follows: by adjusting the mass fraction of acrylamide and adding an appropriate amount of chelating agent EDTA, the side reactions during the acidolysis process are controlled by utilizing the chelating agent's property of chelating metal ions. This effectively improves the purity and extraction rate of phosphoric acid without affecting the original dispersion performance of the dispersant. Reasonable mass fraction control ensures that the chelating agent can function effectively without causing negative impacts, providing a strong guarantee for the production of high-quality phosphoric acid products, and demonstrating good application prospects and economic benefits.

[0032] Furthermore, the organic dispersants prepared in the above three embodiments were added to the phosphate rock slurry, and the mixed phosphate rock slurry was dewatered using a plate and frame filter press. The moisture content of the dewatered phosphate rock slurry was then measured, and the results are shown in the table below:

[0033] Moisture content of phosphate rock slurry (%) Moisture content (%) of phosphate rock slurry Production (t / h) Example 1 13.5 10.4 2.5 Example 2 12.8 9.9 2.8 Example 3 13.1 10.3 2.6

[0034] As can be seen from the table above, after being mixed and conditioned with the organic dispersant described in this application, the moisture content of the same mineral material can be reduced by 2-3 percentage points, so that the mineral material after being filtered by the plate and frame filter press will not adhere during the transportation and filtration process, which greatly improves production efficiency and reduces operating costs.

[0035] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An organic dispersant for preparing phosphoric acid from phosphate rock, characterized in that, It comprises acrylamide, dimethylpropene ammonium chloride, surfactant, initiator and water; the initiator is a compound of 2,2'-azo(2-amidinylpropane) dihydroxyl, dimethyl carbonate and potassium persulfate.

2. The organic dispersant for preparing phosphoric acid from phosphate rock according to claim 1, characterized in that, The mass ratio of the 2,2'-azo(2-amidinylpropane) dihydroxyl, dimethyl carbonate, and potassium persulfate is 1:0.5:

1.

3. The organic dispersant for preparing phosphoric acid from phosphate rock according to claim 1, characterized in that, The acrylamide has a mass fraction of 0.5% to 0.8%.

4. The organic dispersant for preparing phosphoric acid from phosphate rock according to claim 3, characterized in that, The organic dispersant further comprises a chelating agent EDTA, wherein the mass fraction of EDTA is 0.1% to 0.2%.

5. An organic dispersant for preparing phosphoric acid from phosphate rock according to claim 4, characterized in that, The surfactant is a nonionic or anionic surfactant.

6. An organic dispersant for preparing phosphoric acid from phosphate rock according to claim 4, characterized in that, The mass ratio of dimethylpropene ammonium chloride to acrylamide is greater than 20:

1.

7. A method for preparing an organic dispersant for phosphoric acid preparation from phosphate rock according to any one of claims 1-6, characterized in that, The process includes the following steps: mixing acrylamide, dimethylpropene ammonium chloride, surfactant, initiator and water evenly, and generating an organic dispersant through an initiation reaction.

8. The method according to claim 7, characterized in that, The initiator addition step includes mixing 2,2'-azo(2-amidinylpropane) dihydroxyl, dimethyl carbonate and potassium persulfate in a mass ratio of 1:0.5:1 and then adding them to the reaction system.

9. The method according to claim 8, characterized in that, The initiation reaction is carried out under inert gas protection, and the reaction temperature is higher than the ambient temperature but lower than 50°C.

10. A method for preparing an organic dispersant for phosphoric acid using a phosphate rock according to any one of claims 1-6, characterized in that, Dilute the organic dispersant to 0.1%-1%, and put the diluted organic dispersant into the phosphate rock slurry tank 10m in front of the plate and frame filter press, so that it can be fully mixed with the phosphate rock slurry by the flow rate.