CN-121202372-B - Anodic oxidation linear acid polishing purification recovery process

Abstract

The invention relates to the technical field of sewage treatment and discloses an anodic oxidation linear acid throwing purification recovery process which comprises the steps of S1, pretreating waste acid liquid, wherein the waste acid liquid firstly enters a PP pretreatment tank to remove large particle impurities contained in the waste acid, prevent a subsequent membrane filtration system and a resin column from being blocked by particles and protect core treatment equipment, S2, carrying out primary membrane filtration treatment, and enabling the pretreated waste acid liquid to enter a primary acid-resistant UF ultrafiltration membrane unit of a two-stage membrane filtration system, and further remove residual fine particles and large molecular impurities in the waste acid through the physical interception effect of a special acid-resistant ultrafiltration membrane, thereby improving the cleanliness of the acid liquid. The invention is provided with a guide piece, the guide plate adopts an inclined angle that the inner end is slightly lower near the steady flow cavity and the outer end is slightly higher near the cylinder tank wall, the water flow path is forcedly changed through the physical gradient, and when the water flow of the outer annular pipe of the water distributor falls to the outer end of the guide plate, the guide plate can slide along the direction of the inclined surface tank wall.

Inventors

• XIAO JIANGANG
• LIU NING
• HE YUEWEN

Assignees

• 广东省和佳环保科技有限公司

Dates

Publication Date

20260512

Application Date

20251104

Claims (5)

1. 1. An anodic oxidation linear acid polishing purification recovery process is characterized by comprising the following steps: s1, pre-treating waste acid liquid, namely, firstly, enabling the waste acid liquid to enter a PP pre-treatment tank to remove large particle impurities contained in the waste acid; S2, performing primary membrane filtration treatment, and enabling the pretreated waste acid liquid to enter a primary acid-resistant UF ultrafiltration membrane unit of a two-stage membrane filtration system to remove residual fine particles and macromolecular impurities in the waste acid; S3, performing secondary aluminum ion removal treatment, namely enabling the acid liquor subjected to the primary ultrafiltration membrane treatment to enter a secondary acid-resistant aluminum ion removal resin pile unit of a two-stage membrane filtration system, and simultaneously supplying pure water to the resin pile by a pure water system; s4, aluminum-containing wastewater treatment, namely conveying the aluminum-containing wastewater generated in the secondary acid-resistant aluminum-ion-removing resin pile treatment process to a centralized comprehensive recycling zero-emission system for subsequent harmless treatment and resource recovery; S5, concentrating and preprocessing the low-concentration acid liquor, and enabling the low-concentration acid liquor generated by the secondary acid-resistant dealumination ion resin pile to enter a phosphoric acid low-temperature evaporation concentration system; s6, carrying out evaporation treatment at the low temperature of 90 ℃ at the highest temperature by a phosphoric acid low-temperature evaporation concentration system under a negative pressure state to remove redundant water in the acid liquor, wherein distilled water is generated after the treatment, and flows back to a pure water system for recycling, and recycling acid with the specific gravity of more than 1.67 is obtained on the other hand, so that the acid liquor is recycled; the two-stage membrane filtration system in S2 comprises two-stage membrane filtration equipment (1), wherein a resin column (2) is arranged inside the two-stage membrane filtration equipment (1), the resin column (2) comprises a column body (21), a water distributor (22) is arranged at the top end of the column body (21), and a flow guide piece (23), a flow stabilizing piece (24), a resin layer (25), a supporting layer (26) and a sewage outlet (27) are sequentially arranged inside the column body (21) from top to bottom; The resin layer (25) is arranged below the steady flow piece (24) and is used for adsorbing aluminum ions in waste acid, the supporting layer (26) is arranged below the resin layer (25) and is used for supporting the resin layer (25), and the drain outlet (27) is arranged at the bottom of the column (21) and is used for discharging impurities deposited by the supporting layer (26); the top end of the inner wall of the guide piece (23) is close to the outer ring of the water distributor (22), and the water flowing out of the water distributor (22) is guided to diffuse towards the tank wall, the steady flow piece (24) comprises a steady flow cavity (241), the center of the steady flow cavity (241) and the center of the water distributor (22) are coaxially distributed, and the central water flow of the water distributor (22) can be accurately injected into the steady flow cavity (241); The guide piece (23) comprises a guide plate (231), the guide plate (231) is obliquely arranged in a mode of being low in the inside and high in the outside, the outer end of the guide plate (231) is close to the tank wall of the column body (21), and the inner end of the guide plate is close to the steady flow cavity (241); The steady flow cavity (241) is of an inverted hemispherical design, the diameter of the steady flow cavity (241) is smaller than the inner diameter of the column body (21), and an annular gap is formed between the outer wall of the steady flow cavity (241) and the inner wall of the column body (21) and is used for receiving water flow guided to the tank wall by the guide plate (231); the steady flow piece (24) further comprises a bottom plate (243) arranged at one end, close to the resin layer (25), of the steady flow cavity (241), a penetrating hole (245) is formed in the bottom plate (243), and a supporting plate (246) is circumferentially arranged at the side edge of the bottom plate (243); the steady flow piece (24) further comprises a diversion opening (242) arranged at the top end of the steady flow cavity (241).
2. 2. The anodic oxidation linear acid polishing purification recovery process of claim 1, wherein the guide piece (23) further comprises a positioning block (232) and a connecting ring (233), the positioning block (232) is arranged on the side edge of the guide plate (231), the positioning block (232) is connected with a positioning groove (211) formed in the inner wall of the cylinder (21), and the connecting ring (233) is arranged at the bottom end of the guide plate (231) and is used for connecting the guide plate (231) in series.
3. 3. The anodic oxidation linear acid polishing purification recovery process of claim 2, wherein the connecting ring (233) is made of acid-resistant materials, and an acid-resistant glue sealing layer is arranged at the joint of the connecting ring (233) and the guide plate (231).
4. 4. The anodic oxidation linear acid polishing purification recovery process of claim 1, wherein the support plate (246) is of L-shaped design, a silica gel pad is arranged at the bottom of the support plate (246), and the silica gel pad is in contact with a layered grid of the resin layer (25).
5. 5. The anodic oxidation linear acid polishing purification recovery process of claim 1, wherein the diversion opening (242) is arranged in the middle of the top end of the steady flow cavity (241), and the edge of the top end of the diversion opening (242) protrudes upwards to form an annular flange.

Description

Anodic oxidation linear acid polishing purification recovery process Technical Field The invention relates to the technical field of sewage treatment, in particular to an anodic oxidation linear acid polishing purification and recovery process. Background The application of the aluminum material is not separated from the surface anodic oxidation treatment, so that the anodic oxidation industry can obtain unprecedented expansion in quantity and scale, most of anodic aluminum products are subjected to chemical polishing treatment, namely chemical polishing, and chemical polishing waste acid is derived from chemical polishing waste tank liquid and washing liquid of a washing tank of an anodic oxidation enterprise. In the traditional chemical polishing process, only a small part of acid reacts with aluminum, and the other large part of acid is attached to the surface of a workpiece and is brought to a washing tank to flow into a sewage treatment station; the combined process of the ultrafiltration membrane and the resin column in actual production is widely applied to waste acid water purification treatment, in particular to high pollution industries such as anodic oxidation, electroplating, chemical industry and the like. The core causes of unstable adsorption efficiency of the existing resin column are unmatched with the flow characteristics of waste acid due to structural limitations of traditional water distribution equipment, most of water distributors are single-point water inlet at the top, only distribute water downwards through the fixed aperture of an umbrella-shaped disc surface, but cannot cover the whole domain of the inner wall of the resin column, water flow is influenced by gravity and the diameter of the column body and naturally converged towards the middle part of the column body to form a water distribution pattern with strong center and weak edge, and the periphery of the column wall is in a water shortage state for a long time on the resin layer formed by about two to three of the periphery of the column wall. The uneven water distribution can directly promote local short circuit, the middle resin is continuously contacted with high-concentration waste acid, the upper limit of aluminum ion adsorption (oversaturation) is reached only one to two days, the edge resin is not involved in adsorption and is still in an idle state, and after the middle resin is saturated, the non-adsorbed aluminum ions can directly penetrate through a resin layer along with water flow, so that the aluminum ion removal rate is suddenly reduced from the initial 99% to below 70%. The aluminum content of the finally purified acid liquor often exceeds the reuse standard of one gram per liter of zero point, so that the acid liquor cannot be directly reused in the chemical throwing tank, and the acid liquor is required to be returned to the pretreatment system again for secondary treatment, so that the rework cost of more than three products is increased, the equipment treatment capacity is occupied, the overall acid liquor recovery efficiency is reduced by five to two products, and the water inlet load of the sewage treatment station is indirectly increased. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides an anodic oxidation linear acid polishing purification recovery process, which can effectively solve the problems of uneven water distribution, reduced aluminum ion removal rate, substandard acid liquor and rising cost caused by traditional water distribution equipment in the prior art. In order to achieve the above purpose, the invention is realized by the following technical scheme: the invention provides an anodic oxidation linear acid polishing purification and recovery process, which comprises the following steps: S1, pre-treating waste acid liquid, wherein the waste acid liquid firstly enters a PP pre-treatment tank, so that large particle impurities contained in waste acid are removed, a subsequent membrane filtration system and a resin column are prevented from being blocked by particles, and core treatment equipment is protected; s2, performing primary membrane filtration treatment, wherein the pretreated waste acid liquor enters a primary acid-resistant UF ultrafiltration membrane unit of a two-stage membrane filtration system, and further removing residual fine particles and macromolecular impurities in the waste acid through the physical interception effect of a special acid-resistant ultrafiltration membrane, so that the cleanliness of the acid liquor is improved; s3, performing secondary aluminum ion removal treatment, namely enabling the acid liquor subjected to the primary ultrafiltration membrane treatment to enter a secondary acid-resistant aluminum ion removal resin pile unit of a two-stage membrane filtration system, and simultaneously supplying pure water to the resin pile by a pure water system; S4, aluminum-containing wastewater treatment, namely al