Phosphorus tailing solid-liquid separation filter aid and application

Abstract

The invention provides a phosphate tailing solid-liquid separation filter aid and application. The filter aid is prepared from the following components in percentage by weight: 10 to 15 percent of water-soluble carbon nanotubes, 20 to 25 percent of maleic anhydride grafted ethylene glycol copolymer, 1 to 2 percent of nano titanium dioxide, 10 to 15 percent of C20-22 alcohol polyoxyethylene ether, 20 to 30 percent of cationic polyacrylamide, 5 to 10 percent of carboxymethyl cellulose, 2 to 5 percent of modified sodium silicate and 1 to 2 percent of nonylphenol polyoxyethylene ether. The filter aid disclosed by the invention is prepared into an aqueous solution with the concentration of 0.1-0.3%, and 50-110g / t of tailing dry basis is added in the flotation tailing thickening process, so that the concentration of thick ore pulp reaches more than 60%; before dense ore pulp is filtered, 50-100g / t of a filter aid of a tailing dry basis is added to act with the dense ore pulp, and then filter pressing work is performed, so that the flotation tailing solid-liquid separation effect is effectively improved, the single cycle time of filter pressing is shortened, the water content and viscosity of a filter cake are reduced, discharging is convenient, meanwhile, the service cycle of filter cloth can be prolonged, and the cleaning difficulty can be lowered; the method has important economic and environment-friendly significance.

Description

Technical Field

[0001] The invention belongs to the field of mineral processing, and particularly relates to a solid-liquid separation filter aid for phosphate tailings and an application thereof. Background Art

[0002] The dealuminated phosphate tailings from reverse flotation are mainly composed of minerals such as feldspar, quartz, dolomite and calcite. The ore composition is complex, the particle size is fine and the viscosity is high. Traditional single polymer and inorganic filter aids are not effective in mineral particle sedimentation and dehydration, resulting in high viscosity of the filter cake. Therefore, the development of new filter aids is of great significance to improve the solid-liquid separation effect of dealuminated flotation tailings and improve the properties of the filter cake.

[0003] Patent CN116213430A discloses a harmless treatment system and method for phosphate tailings, which achieves the purpose of reducing the moisture content of phosphate tailings by adding a conditioning modifier to the dense phosphate tailings slurry to achieve mixing uniformity and filter cake washing functions. Patent CN101985100B discloses a filter aid for phosphate reverse flotation tailings filtration and a preparation method, which uses sodium methylene dinaphthalene sulfonate and sodium disulfonated succinate to prepare a filter aid for phosphate reverse flotation tailings filtration, and is applied to phosphate reverse flotation tailings filtration, effectively reducing the moisture content of the tailings filter cake and the mud content of the filtrate.

[0004] Water-soluble carbon nanotubes have high surface area and good dispersibility, can be evenly distributed in the slurry, form a stable suspension system, provide strength and air permeability for the slurry, and form fine drainage channels; maleic anhydride grafted ethylene glycol copolymer strengthens the stability of flocs through electrical regulation and bridging, forming larger and more stable flocs. Applying the two in the solid-liquid separation process of phosphate tailings can effectively improve the solid-liquid separation effect. In order to avoid the drawbacks of a single agent, the present invention uses polymeric filter aids as the main body, and uses water-soluble carbon nanotubes and maleic anhydride grafted ethylene glycol copolymers and other agents in a coordinated manner to effectively improve the solid-liquid separation efficiency of phosphate tailings. Summary of the invention

[0005] The present invention combines the structure and air permeability of water-soluble carbon nanotubes and the electrical regulation and cross-linking effect of maleic anhydride grafted ethylene glycol copolymers, and on this basis, combines polymeric filter aids to provide a phosphate tailings solid-liquid separation filter aid and its application. The filter aid of the present invention has a good filtering effect, and the preparation method is simple, and has the advantages of low water content and low viscosity of the tailings filter cake, short single cycle time of filter pressing, etc.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: A filter aid for solid-liquid separation of phosphate tailings comprises the following components by mass percentage: 10-15% of water-soluble carbon nanotubes, 20-25% of maleic anhydride grafted ethylene glycol copolymer, 1-2% of nano titanium dioxide, 10-15% of C20-22 alcohol polyoxyethylene ether, 20-30% of cationic polyacrylamide, 5-10% of carboxymethyl cellulose, 2-5% of modified sodium silicate and 1-2% of nonylphenol polyoxyethylene ether.

[0007] Preferably, the molecular weight of the cationic polyacrylamide is 10 million to 12 million.

[0008] The present invention also provides an application of the solid-liquid separation filter aid for phosphate tailings, comprising the following steps: S1, mixing the filter aids to prepare an aqueous solution of 1‰-3‰, preferably 2‰; S2, pre-treating the tailings slurry, adding water to adjust the slurry, and adding quicklime to control the pH of the slurry; S3, add the filter aid of S1 and the tailings pulp of S2 into the thickener for flocculation and sedimentation treatment, so that the concentration of the pulp after thickening is 60%-65%; S4. Add filter aid to the outlet of the underflow pipeline of the thickener in S3, mix and stir for 20-60 minutes, and then enter the plate and frame filter press for filtration. After the filtration is completed, unload the filter cake.

[0009] Preferably, in step S2, quicklime is added to control the pH value of the slurry to 7-8, and water is added to adjust the slurry to control the slurry concentration to 20%-50%.

[0010] Preferably, the flocculation and sedimentation treatment comprises: (1) Primary flocculation stage: filter aid addition amount is 15-30g / t, stirring intensity is 3-8rpm, stirring for 10-15min; (2) Intermediate flocculation and compaction stage: filter aid addition amount is 25-50g / t, stirring intensity is 2-5rpm, stirring for 20-30min; (3) Fine flocculation and sedimentation stage: the amount of filter aid added is 10-30 g / t, the stirring intensity is 1-3 rpm, and the stirring time is 10-20 min.

[0011] In the above-mentioned graded sedimentation treatment, in the preliminary flocculation stage, the filter aid and the slurry are initially in contact to form a preliminary flocculation structure; in the intermediate flocculation and compaction stage, the flocs are further promoted to grow and gradually compacted, thereby improving the sedimentation properties of the slurry and making the initially formed flocs more stable; in the fine flocculation and sedimentation stages, low-intensity stirring is maintained to avoid damage to the formed flocs, thereby promoting further sedimentation and compaction of the flocs in the thickener.

[0012] Preferably, in step S3, the amount of filter aid added is 50-110 g / t tailings dry basis. The filter aid is added during the sedimentation treatment process, and the water-soluble carbon nanotubes in the filter aid play a role in improving the dispersibility and flocculation effect of the filter aid. The maleic anhydride grafted ethylene glycol copolymer promotes the formation of larger and more stable flocs, and synergizes with other components in the filter aid in the tailings thickener, effectively improving the dispersibility and flocculation effect of the filter aid; at the same time, the rheological properties of the slurry are adjusted, the conductivity and viscosity of the slurry are increased, and it is conducive to forming a more stable sedimentation system. Under the action of the filter aid of the present invention, the flocculation and sedimentation effect of the tailings slurry is better, and the floc diameter is increased to 150-250um. As the floc diameter increases, its sedimentation rate also increases, forming a denser flocculation structure, so that the slurry underflow concentration after the concentration process reaches 60%-65%.

[0013] Preferably, in step S4, the amount of the filter aid added is 50-100 g / tailing dry basis. The filter aid is added in the filter press process, wherein the water-soluble carbon nanotubes provide high mechanical strength and excellent permeability of the flocs; the maleic anhydride grafted ethylene glycol copolymer enhances the stability of the flocs through electrical regulation and bridging; the synergistic effect of the two and other components effectively promotes the dehydration effect of the particles, shortening the single cycle time of the filter press to 25-35 minutes, and at the same time, the moisture content of the tailings filter cake drops below 10%, effectively reducing the moisture content and viscosity of the tailings filter cake, and the filter cake can be automatically unloaded without manual assistance.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The filter aid of the present invention enables the concentration of the flotation tailings slurry after thickening to reach more than 60%, significantly increases the solid content of the slurry, and simultaneously reduces the single cycle time of the filter press, reduces the moisture content and viscosity of the filter cake, facilitates unloading, and can extend the service life of the filter cloth and the difficulty of cleaning, significantly improves the solid-liquid separation effect of the flotation tailings, and has important economic and environmental significance. DETAILED DESCRIPTION

[0015] Embodiment 1: This embodiment provides a filter aid of the present invention and its application in solid-liquid separation of aluminum tailings from reverse flotation of collophanite. The filter aid comprises the following components in percentage by mass: 15% water-soluble carbon nanotubes, 20% maleic anhydride grafted ethylene glycol copolymer, 2% nano titanium dioxide, 18% C20-22 alcohol polyoxyethylene ether, 30% cationic polyacrylamide (molecular weight of 10 million to 12 million), 10% carboxymethyl cellulose, 3% modified sodium silicate and 2% nonylphenol polyoxyethylene ether.

[0016] The application of the filter aid in the solid-liquid separation of aluminum tailings from the reverse flotation of collophanite specifically comprises the following steps: S1, preparing the above filter aid into a 2‰ filter aid aqueous solution; S2. Add 55 cubic meters of water / h to the aluminum tailings from the reverse flotation of the collophanite to control the pulp concentration to 25%, add quicklime to control the pulp pH to 8, and stir for 2 minutes; S3, add the filter aid of S1 and the tailings pulp of S2 into the thickener for flocculation and sedimentation treatment, so that the concentration of the thick pulp is 65%; The flocculation and sedimentation treatment comprises: (1) Primary flocculation stage: filter aid addition amount 0-15g / t, stirring intensity 5rpm, stirring for 15min; (2) Intermediate flocculation and compaction stage: filter aid addition amount 0-40g / t, stirring intensity 5rpm, stirring for 20min; (3) Fine flocculation and sedimentation stage: filter aid addition amount 0-15g / t, stirring intensity 2rpm, stirring for 15min; S4. Add filter aid to the outlet of the underflow pipeline of the thickener in S3. After mixing for 30 minutes, enter the plate and frame filter press for filtration. After the filtration is completed, discharge the filter cake. Among them, the amount of agent added is 0-100g / t, and the application results are shown in Table 1.

[0017] Table 1

[0018] Embodiment 2: This embodiment provides a filter aid of the present invention and its application in solid-liquid separation of feldspar tailings from cationic reverse flotation of collophanite. The filter aid comprises the following components in percentage by mass: 13% water-soluble carbon nanotubes, 22% maleic anhydride grafted ethylene glycol copolymer, 2% nano titanium dioxide, 18% C20-22 alcohol polyoxyethylene ether, 30% cationic polyacrylamide (molecular weight of 10 million to 12 million), 10% carboxymethyl cellulose, 3% modified sodium silicate and 2% nonylphenol polyoxyethylene ether.

[0019] The application of the filter aid in the solid-liquid separation of the feldspar tailings from the cationic reverse flotation of collophanite specifically comprises the following steps: S1, preparing the above filter aid into a 2‰ filter aid aqueous solution; S2. Add 55 cubic meters of water / h to the aluminum tailings from the reverse flotation of collophanite to control the pulp concentration to 25%; add quicklime to control the pulp pH to 8 and stir for 2 minutes; S3, adding the filter aid of S1 and the tailings slurry and filter aid of S2 into a thickener for flocculation and sedimentation treatment, so that the concentration of the slurry after thickening is 65%; The flocculation and sedimentation treatment comprises: Primary flocculation stage: filter aid addition amount 0-15g / t, stirring intensity 5rpm, stirring for 15min; (2) Intermediate flocculation and compaction stage: filter aid addition amount 0-40g / t, stirring intensity 5rpm, stirring for 20min; (3) Fine flocculation and sedimentation stage: the amount of filter aid added is 0-15 g / t, the stirring intensity is 2 rpm, and the stirring time is 15 min.

[0020] S4. Add filter aid to the outlet of the underflow pipeline of the thickener in S3. After mixing for 30 minutes, enter the plate and frame filter press for filtration. After the filtration is completed, unload the filter cake. Among them, the amount of agent added is 0-100g / t. The application results are as follows: Table 2

[0021] Embodiment 3: This embodiment provides a filter aid of the present invention and its application in solid-liquid separation of feldspar tailings from cationic reverse flotation of collophanite. The filter aid comprises the following components in mass percentage: 10% water-soluble carbon nanotubes, 25% maleic anhydride grafted ethylene glycol copolymer, 2% nano titanium dioxide, 18% C20-22 alcohol polyoxyethylene ether, 30% cationic polyacrylamide (molecular weight of 10 million to 12 million), 10% carboxymethyl cellulose, 3% modified sodium silicate and 2% nonylphenol polyoxyethylene ether.

[0022] The application of the filter aid in the solid-liquid separation of the feldspar tailings from the cationic reverse flotation of collophanite specifically comprises the following steps: S1, preparing the above filter aid into a 2‰ filter aid aqueous solution; S2. Add 35 cubic meters of water / h to the aluminum tailings from the reverse flotation of collophanite to control the pulp concentration to 25%; add quicklime to control the pulp pH to 8 and stir for 2 minutes; S3, adding the filter aid of S1 and the tailings slurry and filter aid of S2 into a thickener for flocculation and sedimentation treatment, so that the concentration of the slurry after thickening is 64%; The flocculation and sedimentation treatment comprises: Primary flocculation stage: filter aid addition amount 0-15g / t, stirring intensity 5rpm, stirring for 15min; (2) Intermediate flocculation and compaction stage: filter aid addition amount 0-40g / t, stirring intensity 5rpm, stirring for 20min; (3) Fine flocculation and sedimentation stage: the amount of filter aid added is 0-15g / t, the stirring intensity is 2rpm, and the stirring time is 15min.

[0023] S4. Add filter aid to the outlet of the underflow pipeline of the thickener in S3. After mixing for 30 minutes, enter the plate and frame filter press for filtration. After the filtration is completed, unload the filter cake. Among them, the amount of agent added is 0-100g / t. The application results are as follows: Table 3

[0024] Comparative Example 1: The same as Example 1, the only difference is that the filter aid formula does not contain water-soluble carbon nanotubes. The application results are shown in the following table: Table 4

[0025] Comparative Example 2: The same as Example 1, the only difference is that the filter aid formula does not contain maleic anhydride grafted ethylene glycol copolymer. The application results are shown in the following table: Table 5

[0026] Comparative Example 3: The same as Example 2, the only difference is that the filter aid formula does not contain water-soluble carbon nanotubes. The application results are shown in the following table: Table 6

[0027] Comparative Example 4: The same as Example 2, the only difference is that the filter aid formula does not contain maleic anhydride grafted ethylene glycol copolymer. The application results are shown in the following table: Table 7

[0028] Comparative Example 5: The same as Example 3, the only difference is that the filter aid formula does not contain water-soluble carbon nanotubes. The application results are shown in the following table: Table 8

[0029] Comparative Example 6: The same as Example 3, the only difference is that the filter aid formula does not contain maleic anhydride grafted ethylene glycol copolymer. The application results are shown in the following table: Table 9

[0030] As shown in Tables 1-9, the filter aids of Comparative Examples 1-6 do not contain water-soluble carbon nanotubes or maleic anhydride grafted ethylene glycol copolymers, so the filter cake has a higher single cycle time and moisture content than the examples, and the filter cake has a higher viscosity, requiring manual unloading; while the filter cake of the examples has a lower viscosity and can be unloaded naturally. It can be seen that the filter aid of the present invention contains water-soluble carbon nanotubes and maleic anhydride grafted ethylene glycol copolymers, and the combined effect of the two and other components in the filter aid improves the solid-liquid separation effect of the flotation tail, reduces the single cycle time of the filter press, and reduces the moisture content and viscosity of the filter cake, making unloading convenient and significantly improving production efficiency.

[0031] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A filter aid for solid-liquid separation of phosphate tailings, characterized in that: The filter aid comprises the following components by mass percentage: 10-15% of water-soluble carbon nanotubes, 20-25% of maleic anhydride grafted ethylene glycol copolymer, 1-2% of nano titanium dioxide, 10-15% of C20-22 alcohol polyoxyethylene ether, 20-30% of cationic polyacrylamide, 5-10% of carboxymethyl cellulose, 2-5% of modified sodium silicate and 1-2% of nonylphenol polyoxyethylene ether.

2. The phosphate tailings solid-liquid separation filter aid according to claim 1, characterized in that The molecular weight of cationic polyacrylamide is 10 million to 12 million.

3. The use of the filter aid for solid-liquid separation of phosphate tailings according to any one of claims 1 to 2, characterized in that: The application comprises the following steps: S1, mixing the filter aids and preparing them into a 1‰-3‰ aqueous solution, preferably 2‰; S2, pre-treat the flotation tailings, add water to adjust the slurry, and add quicklime to control the pH of the slurry; S3, adding the pre-treated tailings slurry and filter aid into the thickener for flocculation and sedimentation treatment, so that the concentration of the slurry after thickening is 60%-65%; S4. Add filter aid to the outlet of the thickener underflow pipeline. After mixing for 20-60 minutes, enter the plate and frame filter press for filtration. After the filtration is completed, discharge the filter cake.

4. The use of the solid-liquid separation filter aid for phosphate tailings according to claim 3, characterized in that: In step S2, water is added to control the slurry concentration to 20%-50%, quicklime is added to control the slurry pH value to 7-8, and the stirring time is 1-3 minutes.

5. The use of the filter aid for solid-liquid separation of phosphate tailings according to claim 3, characterized in that: In step S3, flocculation and sedimentation include: (1) Primary flocculation stage: filter aid addition amount is 15-30g / t, stirring intensity is 3-8rpm, stirring for 10-15min; (2) Intermediate flocculation and compaction stage: filter aid addition amount is 25-50g / t, stirring intensity is 2-5rpm, stirring for 20-30min; (3) Fine flocculation and sedimentation stage: the amount of filter aid added is 10-30 g / t, the stirring intensity is 1-3 rpm, and the stirring time is 10-20 min.

6. The use of the filter aid for solid-liquid separation of phosphate tailings according to claim 3, characterized in that: In step S3, the amount of filter aid added is 50-110 g / t dry basis of tailings.

7. The method for using the solid-liquid separation filter aid for phosphate tailings according to claim 3, characterized in that: In step S4, the added amount of the filter aid is 50-100 g / dry basis of tailings.

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