Search

CN-121990740-A - Preparation process and device of flocculant for heavy metal-containing industrial sludge

CN121990740ACN 121990740 ACN121990740 ACN 121990740ACN-121990740-A

Abstract

The invention discloses a flocculant preparation process and a device for industrial sludge containing heavy metals, which relate to the technical field of sewage treatment material processing, the preparation process is improved on the basis of an original chemical grafting scheme, the total quality of a target solid product is used as a production target, a small-scale and multi-round scheme is adopted for batch production, the effective component quantity of each batch is controlled based on the technical theory of mother liquor effective component enrichment, the target solid flocculant is produced for multiple times, meanwhile, the concentration of the mother liquor finally produced after the mother liquor is enriched for multiple times accords with the industry standard, the whole process is free from liquid metabolite generation, the later drying stage adopts a scheme of centrifugal filtration and hot air drying and crushing to replace the traditional spray drying tower, the equipment cost is reduced, and simultaneously, the heat generated in the drying stage is used for preheating in the drying front stage and the scheme front-stage mixing and curing process for heat preservation, so that the heat is efficiently utilized, and the cost is further reduced.

Inventors

  • WANG ZHIEN
  • CHEN HUI
  • WANG ZHIJIAN

Assignees

  • 上海恒铼新材料有限公司

Dates

Publication Date
20260508
Application Date
20260408

Claims (10)

  1. 1. A preparation process and a device of a flocculant for heavy metal-containing industrial sludge are characterized by comprising the following steps: S1, mixing a solvent with a basic phase, and adding a functional phase to prepare a first-order flocculant solution; s2, accelerating curing, reducing reaction activation energy and strengthening microscopic mass transfer under the synergistic catalysis of hydrodynamic cavitation and multi-frequency ultrasonic waves, and combining the solution to form weak hydrogen bonds, wherein a basic phase and a function are combined; s3, adding a coagulant to precipitate a flocculant basic phase and a functional phase combined product; s4, filtering and separating to form flocculant-containing mother liquor and wet material flocculant for later use; S5, reinjection of the mother liquor, namely dynamically calculating and adding water to prepare a second-order flocculant by a PLC control system based on a feedforward-feedback algorithm after measuring the concentration in real time by an online near infrared spectrometer, and continuously repeating until the raw materials are consumed, so as to obtain a wet flocculant and a flocculant-containing mother liquor, and circularly operating for a plurality of times in a concentration increasing mode, so that the concentration of the mother liquor gradually increases to be close to that of an aqueous flocculant; S6, dehydrating and drying the wet flocculant to produce a solid flocculant finished product and water vapor, and deeply recovering latent heat of the water vapor through a heat pump system, wherein the heated heating medium is used for regulating temperature in the second round of operation S1, and is used for preparing the mother liquor S5 after being condensed into water; and S7, the flocculant-containing mother liquor in S5 is subjected to concentration fine adjustment to form flocculant aqueous agent output.
  2. 2. The process for preparing the flocculant for heavy metal-containing industrial sludge according to claim 1, wherein in the step S1, the basic phase is an inorganic flocculant for providing a net skeleton for a final product flocculant, and the functional phase is a small molecule chelating agent grafted to a molecular chain of the inorganic flocculant by adopting a chemical grafting composite process to form an integrated structure of an inorganic skeleton and an organic group.
  3. 3. The process for preparing the flocculant for heavy metal-containing industrial sludge according to claim 2, wherein the basic phase is formed by mixing PAFC stock solution with water after 200 meshes of filtration, the functional phase is formed by mixing STDC stock solution and PEG, adding the mixture into the basic phase, stirring and mixing in a low-speed large-shearing mode to promote the basic phase to fully contact with the functional phase, and the basic phase and the functional phase are added in a supersaturation proportion, so that the total content of active ingredients in the curing solution after curing in the step S2 is more than or equal to 22%.
  4. 4. The process for preparing a flocculant for heavy metal-containing industrial sludge according to claim 1, wherein in the step S2, the aging process shortens the aging period by adjusting the aging reaction conditions, which comprises; S21, regulating the pH value of the mixed solution to 6.0-6.5 by adding 5% hydrochloric acid or sodium hydroxide solution before curing, and mixing by adopting a scheme of spraying and stirring the cured solution in the process; s22, regulating the pressure, and raising the pressure in the reaction vessel to 0.12-0.15 MPa before curing; s23, air replacement, namely improving SDTC stability through air in an ammonia replacement kettle, and keeping pressure stable in the curing process; s24, controlling the temperature, namely, introducing a circulating heat conducting medium into a jacket of the container to perform heat preservation, wherein the temperature is controlled to be 28-32 ℃; s25, continuously stirring at low frequency in the curing period to promote system circulation; S26, hydrodynamic cavitation and multi-frequency ultrasonic cooperative treatment, wherein the hydrodynamic cavitation and ultrasonic cavitation effect generated by high-speed fluid through a venturi tube are utilized to generate superposition coupling effect to generate high-density micro bubbles, local extremely high-temperature and high-pressure energy is released when the micro bubbles are broken, the diffusion of PAFC and SDTC molecules is greatly accelerated, the reaction activation energy of chemical grafting is reduced, and the rapid formation of hydroxyl-amino hydrogen bonds is promoted; The mixed solution after curing is measured to meet the zeta potential of +15mV to +20mV.
  5. 5. The process for preparing the flocculant for industrial sludge containing heavy metals according to claim 1, wherein in the step S3, 0.05% -0.1% of anionic PAM is added into the cured composite liquid, the mixture is stirred for 5min at a high speed of 200r/min to ensure uniform dispersion of PAM, and is stirred for 15min at a low speed of 50r/min to promote flocculation, and then the mixture is settled for 2-4 h to form an upper mother liquor plus lower dense solid precipitate, wherein the solid water content is about 80% -85%.
  6. 6. The process for preparing the flocculant for heavy metal-containing industrial sludge according to claim 5, wherein in the step S4, the upper mother liquor and the lower dense solid precipitate are all injected into the filtering equipment for solid-liquid separation, the bottom solid product is discharged after stopping, the upper mother liquor is collected, the upper mother liquor is filtered and decontaminated through 500 meshes and 1500 meshes in sequence, and then the PH is adjusted to 6.0-6.5.
  7. 7. The process for preparing the flocculant for heavy metal-containing industrial sludge according to claim 6, wherein in the step S5, the first-order flocculant is adopted to prepare the produced mother liquor as a solvent, and the concentration is reduced by adding water, and the characteristic absorption peak intensities of PAFC and SDTC in the reinjection mother liquor are obtained in real time through an online near infrared spectrometer during the preparation of the second-order flocculant, a Partial Least Squares (PLS) quantitative correction model is established, the concentration data of the active ingredients are output in real time, and a PLC control system dynamically adjusts the mass ratio of PAFC+ SDTC +PEG in the fresh raw materials to the reinjection mother liquor to be controlled to be 1, 0.8-1 and 1.2 according to the concentration data, so that the concentration of the active ingredients in the mixed system is ensured to be less than or equal to 12% -15%, and the influence of overhigh viscosity on dispersion and grafting is avoided.
  8. 8. The process for preparing the flocculant for heavy metal-containing industrial sludge according to claim 7, wherein in the step S6, the wet flocculant is dried by a dryer, the front end is connected with a preheating section, tail gas is dried by a tail section to perform non-contact heat exchange, meanwhile, the tail gas enters an evaporator end of a heat pump latent heat recovery unit, latent heat released by condensation of water vapor is extracted, the heat medium temperature is raised, the heat medium temperature is then entered into S1 and S2 to be regulated, the heat gradient deep efficient recovery is realized, the powder flocculant is finally and directly produced, the powder flocculant is packaged and stored after being screened, and the water in the tail gas is recovered after condensation and used as the mother liquor in the step S5 for blending.
  9. 9. A flocculant preparation device for heavy metal-containing industrial sludge, designed based on the flocculant preparation process for heavy metal-containing industrial sludge according to any one of claims 1 to 9, characterized by comprising: The reaction kettle (1), the rotation of reaction kettle (1) is provided with agitator (16), be provided with heat preservation jacket (15) in reaction kettle (1) lateral wall, reaction kettle (1) inside still is provided with venturi cavitation ware (17), and reaction kettle (1) outer wall is provided with multifrequency ultrasonic transducer array (18); A discharge pipe (13) is arranged between the horizontal spiral centrifugal machine (2) and the reaction kettle (1), and a dry material discharge port (22) and a liquid discharge port (23) are respectively arranged at two sides of the bottom end of the horizontal spiral centrifugal machine (2); the box-type drying and crushing integrated machine (3) is characterized in that a feed hopper (32) is arranged at one end of the box-type drying and crushing integrated machine, a spiral elevator (5) is arranged between the feed hopper (32) and the dry material discharge hole (22), and a discharging hopper (33) is arranged at the other end of the box-type drying and crushing integrated machine (3); A water inlet pipe (23) is arranged between the mother liquor blending box (4) and the liquid discharge hole (23), a condensation return pipe (37) is arranged between the mother liquor blending box (4) and the box-type drying and crushing integrated machine (3), a reinjection pipe (14) is arranged between the mother liquor blending box (4) and the reaction kettle (1), an online near infrared spectrum probe is arranged in the mother liquor blending box (4), and the mother liquor blending box (4) is connected with a PLC intelligent proportioning control cabinet for intelligently blending the concentration of mother liquor; The evaporator end of the heat pump latent heat recovery unit is connected with a gas circuit where the condensation return pipe (37) is located, and the condenser end of the heat pump latent heat recovery unit is connected with a heat conducting medium circulation loop of the heat preservation jacket (15).
  10. 10. The flocculant preparation device for heavy metal-containing industrial sludge according to claim 9, wherein the stirrer (16) is a turbine stirrer, and a servo motor (12) for driving the stirrer (16) to rotate is fixedly arranged at the top of the reaction kettle (1); the novel drying and crushing integrated machine is characterized in that a preheating insulation sleeve (35) is arranged on the box-type drying and crushing integrated machine (3) and close to a feeding end, a forced air flow return pipe (34) is arranged between the tail end of the box-type drying and crushing integrated machine (3) and the preheating insulation sleeve (35), a connecting pipe (36) is arranged between the tail end of the preheating insulation sleeve (35) and an insulation jacket (15), and a condensing return pipe (37) is arranged at the bottom end of the preheating insulation sleeve (35).

Description

Preparation process and device of flocculant for heavy metal-containing industrial sludge Technical Field The invention relates to the technical field of sewage treatment material processing, in particular to a preparation process and a device of a flocculant for heavy metal-containing industrial sludge. Background The flocculant is a material frequently used in industrial manufacturing, especially in the scenes of PCB, water treatment, chemical separation and the like, and the dispersed colloid or suspended particles are aggregated to form large flocs through the actions of adsorption, bridging, net capturing and the like, so that solid-liquid separation is realized, and the flocculant is mainly divided into inorganic flocculant and organic flocculant according to the types of materials, wherein the inorganic flocculant takes charge neutralization as a primary mechanism, a small amount of net capturing and sweeping is assisted, the organic flocculant takes adsorption bridging as a primary mechanism, charge neutralization is assisted, and a certain type of flocculant is seldom used independently in the industrial scene, and the core reasons are that the inorganic flocculant can efficiently destroy colloid stability, but the flocs are tiny and slow to settle, the organic flocculant can quickly aggregate, but cannot directly destabilize stable colloid, so that the traditional flocculant mostly adopts a composite type. The traditional composite flocculant is divided into a physical composite process and a chemical grafting process from the manufacturing process, the physical composite process does not need chemical reaction, the stable coexistence of the inorganic flocculant and the integrating agent is realized only through ' dispersing-mixing-curing ', the core requirement is that the system is uniformly dispersed and has no layering/precipitation, the integrating agent does not react with inorganic components ', and the chemical grafting is to graft chelating groups (such as DTC and sulfhydryl) onto the molecular chains of the inorganic flocculant through chemical reaction, so that an ' inorganic skeleton-organic chelating group ' integrated structure is formed, and the problems of layering and integrating agent loss possibly occurring in the physical composite process are avoided; Therefore, compared with physical compounding, the flocculant produced by chemical grafting has better effect, but in actual production, chemical grafting needs longer curing time in the early curing stage, so that the grafting rate is ensured to be not lower than 85%; the traditional single stirring or single-frequency ultrasonic method is difficult to overcome mass transfer resistance among macromolecules, meanwhile, in the production process of chemical grafting, the water content of a finished product is large, the spray drying tower is required to be used for spray drying to produce a powder finished product, the spray drying tower is high in equipment cost and use cost, the problem of sewage generation exists, in addition, the existing mother liquor recycling technology mostly adopts static proportion with fixed proportion, lacks of real-time monitoring and dynamic adjustment of the fluctuation of the mother liquor components, easily causes out-of-control product quality after multiple cycles, and the existing heat recovery is only stopped at a sensible heat exchange layer, so that a large amount of latent heat of water vapor is wasted. In particular to a flocculant preparation process and a device for industrial sludge containing heavy metals. Disclosure of Invention The invention aims to provide a flocculant preparation process and device for heavy metal-containing industrial sludge, and aims to solve the problems in the background technology. In order to achieve the purpose, the invention provides the following technical scheme that the flocculant preparation process for the heavy metal-containing industrial sludge comprises the following steps: S1, mixing a solvent with a basic phase, and adding a functional phase to prepare a first-order flocculant solution; s2, accelerating curing, reducing reaction activation energy and strengthening microscopic mass transfer under the synergistic catalysis of hydrodynamic cavitation and multi-frequency ultrasonic waves, and combining the solution to form weak hydrogen bonds, wherein a basic phase and a function are combined; s3, adding a coagulant to precipitate a flocculant basic phase and a functional phase combined product; s4, filtering and separating to form flocculant-containing mother liquor and wet material flocculant for later use; S5, reinjection of the mother liquor, namely dynamically calculating and adding water to prepare a second-order flocculant by a PLC control system based on a feedforward-feedback algorithm after measuring the concentration in real time by an online near infrared spectrometer, and continuously repeating until the raw materials are consumed, so as