PROCESSING METHOD FOR GRAPHITE ACID PURIFICATION WASTEWATER

Abstract

The application discloses a processing method for graphite acid purification wastewater which comprises processing steps of neutralization and precipitation preprocessing, supernatant electrically distilling and vaporizing, electric energy recycling, condensate recycling and vaporization residue regularly discharging. The processing method performs neutralization and precipitation preprocessing to obtain neutralized supernatant, pumps the supernatant into an electric distiller to be vaporized and obtain electric energy for recycling through steam turbine, and acquires vaporization condensate by residual heat exchange. The vaporization condensate reaches the standard of graphite acid purification impurities such as fluorine, chlorine, aluminum, silicon, iron, magnesium, copper, and zinc and the wastewater discharge standard. The steam heat energy can be recycled and transformed into electric energy to save processing cost. Meanwhile, the vaporization condensate can also be used in the graphite purification process to save water resources, which is not only environmentally friendly and efficient, but also intensively economical.

Claims

1. A processing method for graphite acid purification wastewater, wherein the method comprises specific processing steps as follows: step 1 of preprocessing of neutralization and precipitation, comprising: adding alkaline neutralizer into the graphite acid purification wastewater to neutralize the pH value of the purification wastewater to 6-10, obtaining neutralized filtrate by alkaline neutralization and precipitation, and obtaining neutralized supernatant through concentration and sedimentation; step 2 of electrically distilling and vaporizing the supernatant, comprising: pumping the supernatant after neutralization preprocessing, concentration and sedimentation into an electric distiller to be heated and vaporized, obtaining electric energy by means of the vaporized supernatant steam driving a steam turbine to generate power, and condensing and collecting the supernatant which has been driven the steam turbine to generate power by a heat exchanger, to obtain vaporization condensate; step 3 of recycling of the electric energy, comprising: introducing the vaporized supernatant into a power generation system of the steam turbine to generate electricity at first, then introducing the vaporized supernatant into a heat exchanger to be condensed, and using the electric energy generated by the power generation system of the steam turbine as energy source for electric distillation, heating, and vaporization through circulation; step 4 of recycling of the condensate, comprising: using the condensate after vaporization as water used in the graphite purification process through circulation; step 5 of regularly discharging the vaporization residue, comprising: regularly discharging residues by a residue discharging device of an electric distillation vaporizer, wherein the residues are formed by crystallization or precipitation and concentration of some ions in the solution after the supernatant is vaporized and concentrated.

2. The processing method for graphite acid purification wastewater according to claim 1, wherein the electric distiller is connected with an external solar power generation system which serves as the supplement for the electric energy recycled in the step 3.

3. The processing method for graphite acid purification wastewater according to claim 1, wherein in the step 1, one or more of calcium carbonate, quicklime, lime and/or lime slurry is used as the alkaline neutralizer.

4. The processing method for graphite acid purification wastewater according to claim 1, wherein in the step 1, the method for concentration and sedimentation is selected from natural sedimentation, high-efficiency thickener sedimentation or centrifugal sedimentation.

5. The processing method for graphite acid purification wastewater according to claim 1, wherein in the step 2, the exhaust pressure of the electric distiller for heating and vaporization is 0.6 MPa to 3.5 MPa, the vaporized steam passes through the power generation system of the steam turbine, and the exhaust pressure of the steam turbine is 0.11 MPa to 0.55 MPa.

6. The processing method for graphite acid purification wastewater according to claim 1, wherein in the step 3, the electric energy generated by the power generation system of the steam turbine firstly charges the energy storage and conversion system for later use.

7. The processing method for graphite acid purification wastewater according to claim 1, wherein in the step 4, the content of graphite acid purification impurities in the condensate is reduced to 0.1 mg/L to 5 mg/L, and the condensate is directly discharged to the outside; wherein the graphite acid purification impurities comprise fluorine, chlorine, aluminum, silicon, iron, and magnesium.

8. The processing method for graphite acid purification wastewater according to claim 1, wherein in the step 5, the discharging period of the vaporization residue is 1 to 6 hours each time, and the residue discharging time is 1 to 10 min each time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a schematic diagram of a processing method of the application.

DETAILED DESCRIPTION

[0023] The technical solution of the application will be clearly and completely described hereinafter with reference to attached drawings of the application. Based on embodiments of the application, all other embodiments obtained by those of ordinary skill in the art without creative labor shall belong to the scope claimed in the application.

[0024] A processing method for graphite acid purification wastewater is shown in FIG. 1, which includes the following specific processing steps: [0025] step 1 of preprocessing of neutralization and precipitation, including: adding alkaline neutralizer into graphite acid purification wastewater to neutralize the pH value of the purification wastewater to 6-10, obtaining neutralized filtrate by alkaline neutralization and precipitation, and obtaining neutralized supernatant through concentration and sedimentation; [0026] step 2 of electrically distilling and vaporizing the supernatant, including: pumping the supernatant after neutralization preprocessing, concentration and sedimentation into an electric distiller to be heated and vaporized, obtaining electric energy by means of the vaporized supernatant steam driving a steam turbine to generate power, and condensing and collecting the supernatant which has been driven the steam turbine to generate power by a heat exchanger, to obtain vaporization condensate; [0027] step 3 of recycling of the electric energy, including: first introducing the vaporized supernatant into a power generation system of the steam turbine to generate electricity, then introducing the vaporized supernatant into a heat exchanger to be condensed, and using the electric energy generated by the power generation system of the steam turbine as energy source for electric distillation, heating, and vaporization through circulation; [0028] step 4 of recycling of the condensate, including: using the condensate after vaporization as water used in the graphite purification process through circulation; [0029] step 5 of regularly discharging the vaporization residue, including: regularly discharging residues by a residue discharging device of an electric distillation vaporizer, wherein the residues are formed by crystallization or precipitation and concentration of some ions in the solution after the supernatant is vaporized and concentrated.

[0030] In this embodiment, the electric distiller is connected with an external solar power generation system which serves as the supplement for the electric energy recycled in the step 3.

[0031] In this embodiment, in the step 1, one or more of calcium carbonate, quicklime, lime and/or lime slurry is used as the alkaline neutralizer.

[0032] In this embodiment, in the step 1, the method for concentration and sedimentation is selected from natural sedimentation, high-efficiency thickener sedimentation or centrifugal sedimentation.

[0033] In this embodiment, in the step 2, the exhaust pressure of the electric distiller for heating and vaporization is 0.6 MPa to 3.5 MPa, the vaporized steam passes through the power generation system of the steam turbine, and the exhaust pressure of the steam turbine is 0.11 MPa to 0.55 MPa.

[0034] In this embodiment, in the step 3, the electric energy generated by the power generation system of the steam turbine may first charge the energy storage and conversion system for later use.

[0035] In this embodiment, in the step 4, the content of graphite acid purification impurities such as fluorine, chlorine, aluminum, silicon, iron, magnesium, copper and zinc in the condensate may be reduced to 0.1 mg/L to 5 mg/L, and the condensate may also be directly discharged to the outside.

[0036] In this embodiment, in the step 5, the discharging period of the vaporization residue is 1 to 6 hours each time, and the residue discharging time is 1 to 10 min each time.

[0037] As shown in FIG. 1, in this embodiment, the graphite acid purification wastewater is neutralized and precipitated in a thickener, and the thickened sludge obtained after precipitation is converted into comprehensive solid waste for processing. The processing method for graphite acid purification wastewater of the application performs preprocessing of neutralization and precipitation to obtain neutralized supernatant through concentration and sedimentation, pumps the supernatant into an electric distiller to acquire vaporization condensate, the content of graphite acid purification impurities such as fluorine, chlorine, aluminum, silicon, iron, magnesium, copper and zinc in the vaporization condensate reaches the standard, the vaporization condensate reaches the wastewater discharge standard, and the steam heat energy can be recycled and transformed into electric energy of the steam turbine. At the same time, the vaporization condensate can also be used as water used in the graphite purification process to save water resources, which is not only environmentally friendly and efficient, but also intensively economical.

[0038] What described above are only preferred embodiments of the application, and are not intended to limit the application; and various modifications and variations of the application can be made by those skilled in the art. Any modification, equivalent substitution, improvement or the like made within the spirit and principle of the application shall be included in the scope claimed in the application.