Method for extracting ultra high purity alumina from wasterwater

Abstract

An object of the present invention is to provide a novel method for extracting ultra high purity alumina from wastewater. Wastewater is recycled, filtered, concentrated and pretreated in order to mix with alkali solution and extraction agent PX-17, undergoing 2 times of purification, adding control agent SX-1 and high temperature heat treatment to finally obtain ultra high purity nano-alumina particles which purity reaches as 99.999% and particle size reaches as 20200 nm.

Claims

1. A method for extracting nano-alumina from wastewater, characterized in that comprising: (1) filtering wastewater containing Al.sup.3+ with a mesh, and concentrating the filtered wastewater to maintain a Al.sup.3+ mass fraction of 3% to 18%; dropping the concentrated wastewater into a first alkaline solution to obtain a mixture; wherein a mass fraction of alkali in the first alkaline solution reaches 10% to 60%; (2) adding an extraction agent into the mixture from step 1 and stirring the mixture to perform a preliminary extraction; during the preliminary extraction, keeping a pH value at 1-9; maintaining the temperature at 10 C. to 90 C.; adding the extraction agent again for a secondary extraction; wherein an initial dosage of the extraction agent for the preliminary extraction is 1 to 5 g/L, and a stirring time is 30 min to 5 h; a second dosage of the extraction agent for the secondary extraction is 0.1 to .sup.3 g/L, a stirring time is 0.5 to .sup.5 h; (3) adding a control agent into the extracted solution after the secondary extraction from step 2 and stirring; wherein a dosage of the control agent is 0.1 to .sup.5 g/L, stirring for 1 h to .sup.24 h at 20 C. to .sup.280 C.; and adding a second alkaline solution under a pH value of 1 to 10 to precipitate aluminum hydroxide; then cooling, filtering and washing the precipitated aluminum hydroxide with ultra-pure water for 3 to .sup.5 times, and drying the aluminum hydroxide under 80 C. to 120 C. to obtain an aluminum hydroxide precursor; and (4) heating the aluminum hydroxide precursor at 600 C. to 1200 C. for 0.5 to .sup.4 hours; then obtaining the nano alumina by cooling; wherein the wastewater in step (1) contains a surface treatment waste liquid selected from the group comprising aluminum, aluminum plate, aluminum wire, aluminum foil, aluminum brick and aluminum alloy.

2. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that the first alkaline solution in step (1) is selected from a group consisting of sodium hydroxide solution, potassium hydroxide solution, carbonate soda solution, potassium carbonate solution, calcium hydroxide solution and aqueous ammonia.

3. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that the second alkaline solution in step (3) is selected form a group consisting of sodium hydroxide solution, potassium hydroxide solution, carbonate soda solution, potassium carbonate solution, calcium hydroxide solution and aqueous ammonia.

4. The method for extracting nano-alumina from wastewater according to claim 1 characterized in that the extraction agent in step (2) is selected from a group consisting of giant porous ion exchange resin, macroporous zeolite molecular sieve, activated carbon, porous carbon fiber, urea and porous alumina; wherein, the extraction agent further consists of the following components by weight: giant porous ion exchange resins of 18.5% to 22%, macroporous zeolite molecular sieve of 10.5% to 14%, activated carbon of 3.5% to 7%, porous activated carbon fibers of 26.5% to 31%, urea of 14% to 17%, and porous alumina of 22.5% to 27%.

5. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that the extraction agent in step (2) is selected from a group consisting of giant porous ion exchange resin, macroporous zeolite molecular sieve, activated carbon, porous carbon fiber, urea and porous alumina; wherein the extraction agent further consists of the following components by weight: giant porous ion exchange resins of 19.0% to 20%, macroporous zeolite molecular sieve of 10.8% to 12.5%, activated carbon of 3.8% to 5.5%, porous activated carbon fibers of 27% to 28.5%, urea of 14.5% to 16%, and porous alumina of 23% to 24.5%.

6. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that the extraction agent in step (2) is selected from a group consisting of giant porous ion exchange resin, macroporous zeolite molecular sieve, activated carbon, porous carbon fiber, urea, porous alumina; wherein the extraction agent further consists of the following components by weight: giant porous ion exchange resins of 19.5%, macroporous zeolite molecular sieve of 11%, activated carbon of 4%, porous activated carbon fibers of 27.5%, urea of 14.8%, and porous alumina of 23.9%.

7. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that the control agent in step (3) is selected from a group consisting of polyvinyl pyrrolidone, polyethylene glycol-2000, gelatin, polyoxyethylene polyoxypropylene copolymers, polysorbate surfactant, polyvinyl-124, and aluminum hydroxide.

8. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that the nano-alumina in step (4) is taken out and passed through a cooling tunnel at a temperature of 0 C. to 4 C. for 15 min to 90 min.

9. The method for extracting nano-alumina from wastewater according to claim 1, characterized in that a purity of the nano-alumina is 99.992% to 99.999%.

10. An application of the method for extracting nano-alumina from wastewater according to claim 1, characterized in that the method is applied for the retrieving an acidic wastewater containing Al.sup.3+.

Description

BRIEF DESCRIPTION OF THE INVENTION

(1) FIG. 1 is a flow chat of a novel method for extracting ultra high purity nano-alumina from wastewater of the invention.

(2) FIG. 2 is a X-ray Diffraction figure for ultra high purity nano-alumina made by example 5 of the invention.

(3) FIG. 3 is a field emission scanning electron microscopy (FESEM) figure for ultra high purity nano-alumina made by example 5 of the invention.

(4) FIG. 4 is the trace elements residual analysis (ICP-OES) result for ultra high purity nano-alumina made by example 1 of the invention.

(5) FIG. 5 is the trace elements residual analysis (ICP-OES) result ultra high purity nano-alumina made by example 2 of the invention.

(6) FIG. 6 is the trace elements residual analysis (ICP-OES) result for ultra high purity nano-alumina made by example 3 of the invention.

(7) FIG. 7 is the trace elements residual analysis (ICP-OES) result for ultra high purity nano-alumina made by example 4 of the invention.

(8) FIG. 8 is the trace elements residual analysis (ICP-OES) result for ultra high purity nano-alumina made by example 5 of the invention.

(9) The embodiments of the present invention can be better understood by reference to the following examples which are offered by way of illustration. The present invention is not limited to the example given herein.

EXAMPLE 1

(10) As shown in FIG. 1 and FIG. 4, the novel method for extracting ultra high purity nano-alumina from wastewater of the invention is as follows:

(11) Step 1, filter the raw material waste containing aluminum (Al.sup.3+) by Teflon mesh, and concentrate it to maintain aluminum ions (Al.sup.3+) mass fraction of 5%; Then, the concentrated solution is dropped into the alkaline solution while the alkali mass fraction reaches 10%.

(12) Step 2, add extraction agent PX-17 into mixed solution, during extraction process, keep pH value always at 3, maintain the temperature at 30 C.; add extraction agent PX-17 in the preliminary extraction for a secondary extraction, the initial dosage is 1.0 g/L, and stirring time is 0.5 h in the preliminary extraction; the second dosage is 1.2 g/L, and stirring time 0.5 h in the secondary extraction. Wherein the PX-17 component content is as follows: giant porous on exchange resins 18.5% macroporous zeolite molecular sieve 10.5%, activated carbon 5%, porous activated carbon fibers 28%, urea 14%, and porous alumina 24%.

(13) Step 3, add the control agent SX-1 into extract solution, dosage is 0.3 g/L, at 30 C. and stir for 24 h; and add the alkali solution under the pH value as 2 to precipitate the aluminum hydroxide; then cooling, filtering and washing with ultra-pure water for 35 times, drying under 80 C. to obtain pure aluminum hydroxide precursor.

(14) Step 4, heat the pure aluminum hydroxide precursor under 600 C. for 0.5 hours; then obtain the ultra high purity nano alumna by cooling down under 4 C.

(15) Obtain the purity of 99.992% of ultra high purity nano alumina, and the particle size was 200 nm.

EXAMPLE 2

(16) As shown in FIG. 1 and FIG. 5, the novel method for extracting ultra high purity nano-alumina from wastewater of the invention is as follows:

(17) Step 1, filter the raw material waste containing aluminum (Al.sup.3+) by Teflon mesh, and concentrate it to maintain aluminum ions (Al.sup.3+) mass fraction of 8%; Then, the concentrated solution, is dropped into the alkaline solution while the alkali mass fraction reaches 22%.

(18) Step 2, add extraction agent PX-17 into mixed solution, during extraction process, keep pH value always at 5, maintain the temperature at 45 C.; add extraction agent PX-17 in the preliminary extraction for a secondary extraction, the initial dosage is 1.5 g/L, and stirring time is 1.5 h in the preliminary extraction; the second dosage is 2.4 g/L, and stirring time is 1.5 h in the secondary extraction. Wherein the PX-17 component content is as follows: giant porous ion exchange resins 18.5%, macroporous zeolite molecular sieve 11.5%, activated carbon 4.5%, porous activated carbon fibers 27%, urea 14.5%, and porous alumina 24%.

(19) Step 3, add the control agent SX-1 into extract solution, dosage is 1.0 g/L, at 90 C. and stir for 18 h; and add the alkali solution under the pH value as 5 to precipitate the aluminum hydroxide; then cooling, filtering and washing with ultra-pure water for 35 times, drying under 90 C. to obtain pure aluminum hydroxide precursor.

(20) Step 4, heat the pure aluminum hydroxide precursor under 750 C. for 1.5 hours; then obtain the ultra high purity nano alumina by cooling down under 2 C.

(21) Obtain the purity of 99.995% of ultra high purity nano alumina, and the particle size was 180 nm.

EXAMPLE 3

(22) As shown in FIG. 1 and FIG. 6, the novel method for extracting ultra high purity nano-alumina from wastewater of the invention is as follows:

(23) Step 1, filter the raw material waste containing aluminum (Al.sup.3+) by Teflon mesh, and concentrate it to maintain aluminum ions (Al.sup.3+) mass fraction of 11%; Then, the concentrated solution is dropped into the alkaline solution while the alkali mass fraction reaches 34%.

(24) Step 2, add extraction agent PX-17 into mixed solution, during extraction process, keep pH value always at 7, maintain the temperature at 60 C.; add extraction agent PX-17 in the preliminary extraction for a secondary extraction, the initial, dosage is 1.0 g/L, and stirring time is 2.5 h in the preliminary extraction; the second dosage is 1.0 g/L, and stirring time is 2.5 h in the secondary extraction. Wherein the PX-17 component content is as follows: giant porous ion exchange resins 20%, macroporous zeolite molecular sieve 11%, activated carbon 4%, porous activated carbon fibers 26.6%, urea 14.4%, and porous alumina 24%.

(25) Step 3, add the control agent SX-1 into extract solution, dosage is 1.5 g/L, at 158 C. and stir for 12 h; and add the alkali solution under the pH value as 7 to precipitate the aluminum hydroxide; then cooling, filtering and washing with ultra-pure water for 35 times, drying under 100 C. to obtain pure aluminum hydroxide precursor.

(26) Step 4, heat the pure aluminum hydroxide precursor under 900 C. for 2 hours; then obtain the ultra high purity nano alumina by cooling down under 2 C.

(27) Obtain the purity of 99.994% of ultra high purity nano alumina, and the particle size was 150 nm.

EXAMPLE 4

(28) As shown in FIG. 1 and FIG. 7, the novel method for extracting ultra high purity nano-alumina from wastewater of the invention is as follows:

(29) Step 1, filter the raw material waste containing aluminum (Al.sup.3+) by Teflon mesh, and concentrate it to maintain aluminum ions (Al.sup.3+) mass fraction of 14%; Then, the concentrated solution is dropped into the alkaline solution while the alkali mass fraction reaches 46%.

(30) Step 2, add extraction agent PX-17 into mixed solution, during extraction process, keep pH value always at 8, maintain the temperature at 75 C.; add extraction agent PX-17 in the preliminary extraction for a secondary extraction, the initial dosage is 1.5 g/L, and stirring time is 3.5 h in the preliminary extraction; the second dosage is 4.5 g/L, and stirring time is 3.5 h in the secondary extraction. Wherein the PX-17 component content is as follows: giant porous ion exchange resins 18.5%, macroporous zeolite molecular sieve 10.7%, activated carbon 4.3%, porous activated carbon fibers 26.5%, urea 14%, and porous alumina 26%.

(31) Step 3, add the control agent SX-1 into extract solution, dosage is 1.75 g/L, at 200 C. and stir for 6 h; continue add the alkali solution under the pH value as 8 to precipitate the aluminum hydroxide; then cooling, filtering and washing with ultra-pure water for 35 times, drying under 110 C. to obtain pure aluminum hydroxide precursor.

(32) Step 4, heat the pure aluminum hydroxide precursor under 1000 C. for 3 hours; then obtain the ultra high purity nano alumina by cooling down under 0 C.

(33) Obtain the purity of 99.995% of ultra high purity nano alumina, and the particle size was 130 nm.

EXAMPLE 5

(34) As shown in FIG. 1 FIG. 2, FIG. 3 and FIG. 8, the novel method for extracting ultra high purity nano-alumina from wastewater of the invention is as follows:

(35) Step 1, filter the raw material waste containing aluminum (Al.sup.3+) by Teflon mesh, and concentrate it to maintain aluminum ions (Al.sup.3+) mass fraction of 18%; Then, the concentrated solution is dropped into the ammonia solution while the alkali mass fraction reaches 60%.

(36) Step 2, add extraction agent PX-17 into mixed solution, during extraction process, keep pH value always at 4, maintain the temperature at 90 C.; add extraction agent PX-17 in the preliminary extraction for a secondary extraction, the initial dosage is 2.0 g/L, and stirring time is 1 h in the preliminary extraction; the second dosage is 1.25 g/L, and stirring time is 1 h in the secondary extraction. Wherein the PX-17 component content is as follows: giant porous ion exchange resins 19.5%, macroporous zeolite molecular sieve 11%, activated carbon 4%, porous activated carbon fibers 27.5%, urea 14.8%, and porous alumina 23.2%.

(37) Step 3, add the control agent SX-1 into extract solution, dosage is 1.8 g/L, at 280 C. and stir for 1 h; continue add the ammonia solution under the pH value as 8 to precipitate the aluminum hydroxide; then cooling, filtering and washing with ultra-pure water for 35 times, drying under 120 C. to obtain pure aluminum hydroxide precursor.

(38) Step 4, heat the pure aluminum hydroxide precursor under 1200 C. for 2 hours; then obtain the ultra high purity nano alumina by cooling down under 0 C.

(39) Obtain the purity of 99.999% of ultra high purity nano alumina, and the particle size was 100 nm.