Machine-made sand modifier containing residual flocculant and preparation method thereof
Through the synergistic effect of specific composite bacteria population and strong adsorption sacrificial agents, the problem of flocculant residue in machined sand affecting the performance of concrete is solved, efficient degradation and adsorption are achieved, and the flowability and strength of concrete are significantly improved.
Patent Information
- Application Number
- CN202411339251.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2024-12-31
AI Technical Summary
The prior art is difficult to effectively degrade the residual polyacrylamide and polyamine flocculants in the machine sand, affecting the flowability and strength of concrete, and the degradation efficiency of traditional methods is low or there are safety risks.
Using specific complex bacteria populations and strong adsorption sacrificial agents, through the synergistic action of microorganisms and catalyst assistance, heating and microwave treatment, the flocculant is degraded and its adsorption performance is improved, forming a strong adsorption sacrificial agent with nonionic surfactant properties, combined with Biodegradation and adsorption effects to improve the concrete and ease.
It realizes efficient degradation of flocculants in machined sand, improves the flowability and strength of concrete, significantly improves the initial flowability and time loss of concrete, enhances its ease of harmony, and reduces the adsorption effect of flocculants on water. .
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of building materials, and in particular to a machine-made sand modifier containing residual flocculant and a preparation method thereof. Background Art
[0002] In order to avoid environmental pollution, sand making companies usually treat sand washing wastewater by adding flocculants, and recycle the upper clear water for sand washing. Therefore, a certain amount of flocculants will remain on the surface of machine-made sand particles and in the water contained in the machine-made sand. Among many flocculants, polyacrylamide is widely used in the water washing process of machine-made sand by machine-made sand production companies because of its good flocculation and precipitation of impurities. In addition, coagulants such as polyamine and polyaluminium chloride are also used in the treatment of machine-made sand.
[0003] A large number of studies have shown that residual flocculants in machine-made sand will seriously affect the fluidity of the mixed concrete, causing problems such as poor workability. In addition, in addition to fluidity, flocculants will also delay cement hydration to a certain extent, affecting the strength and durability of concrete. There are two main ideas for the problem of residual flocculants in machine-made sand. One is to pre-treat the machine-made sand. Patent CN202111368000.3 discloses a machine-made sand modification device based on ultraviolet irradiation, which uses ultraviolet rays to weaken the association of hydrogen bonds on the surface of machine-made sand and crack the network structure formed by the hydrolysis of flocculants such as polyacrylamide. However, it is difficult for ultraviolet light to degrade all flocculants in a short time, and its degradation efficiency is affected by multiple factors such as power and distance. The second is to add anti-flocculation admixtures to the concrete. Patent CN202311260992.7 uses oxidants such as potassium permanganate to interact with polyacrylamide flocculants, so that the flocculant ions are digested and precipitated into agglomerates, thereby reducing the viscosity of the cement slurry. However, it also takes a long time to digest the flocculant through oxidation, and the concrete mixing time is generally 2 to 3 minutes. Therefore, it is difficult to meet the needs of actual applications. In addition, strong oxidants have certain dangers and limit the application of such materials.
[0004] Therefore, in order to ensure the pouring quality of concrete with machine-made sand containing residual flocculants, it is urgent to develop a machine-made sand modifier containing residual flocculants. Summary of the invention
[0005] In order to solve the problems in the use of existing machine-made sand containing residual flocculants, the purpose of the present invention is to provide a machine-made sand modifier containing residual flocculants and a preparation method thereof.
[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:
[0007] A machine-made sand modifier containing residual flocculants comprises, by weight, 30 to 50 parts of a specific composite bacterial population, 50 to 80 parts of an activator, and 80 to 100 parts of a strong adsorption sacrificial agent.
[0008] The residual flocculant includes one or two of polyacrylamide or polyacrylamide / polyamine composite flocculants, and the activator is obtained by mixing 10% sterile glycerol and glucose in a ratio of 100:(1-5).
[0009] The specific composite bacterial population is prepared according to the following method:
[0010] Step 1: taking 0.5-1 parts of Rhodopseudomonas sphaeroides, 0-0.5 parts of Ralstonia piezoelectrica, 0.5-1 parts of Paracoccus denitrificans and 1-2 parts of Bacillus subtilis respectively by weight and putting them into 1000 parts of enrichment medium for activation, and culturing them at 25-30° C. and 100-120 r / min of shaking conditions for 24-48 hours to obtain culture solution A;
[0011] Step 2: Take 50 portions of the culture solution A in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture them at 25-30° C. and 100-120 r / min for 2-3 days; then add 1 portion of polyamine flocculant, and culture them at 25-30° C. and 100-120 r / min for 2-3 days to obtain culture solution B;
[0012] Step 3, take 50 parts of the culture solution B in step 2 and inoculate them into 1000 parts of the acclimation medium, and add 1.5 parts of polyacrylamide, and culture them at 25-30° C. and 100-120 r / min for 2-3 days; then add 1.5 parts of polyamine flocculant, and culture them at 25-30° C. and 100-120 r / min for 2-3 days to obtain culture solution C;
[0013] Step 4: Take 50 portions of the culture solution C in step 3 and inoculate them into 1000 portions of the acclimation medium, add 2 portions of polyacrylamide, and culture them at 25-30° C. and 100-120 r / min for 2-3 days; then add 2 portions of polyamine flocculant, and culture them at 25-30° C. and 100-120 r / min for 2-3 days to obtain culture solution D;
[0014] Step 5: Take 50 portions of the culture solution D in step 4 and inoculate them into 1000 portions of nutrient medium, and culture them at 25-30° C. and 100-120 r / min of shaking conditions for 24-48 hours to obtain a specific composite bacterial population.
[0015] The enrichment medium is a neutral solution of 5 g / L yeast powder, 10 g / L tryptone, and 10 g / L NaCl, the acclimation medium is a neutral solution of 0.05 g / L yeast powder, 0.5 g / L NaCl, 1.0 g / L K2HPO4, and 0.1 g / L MgSO4, and the nutrient medium is a neutral solution of 3 g / L beef extract, 10 g / L peptone, and 5 g / L NaCl. The polyacrylamide is one of anionic polyacrylamide and cationic polyacrylamide, and the molecular weight is 12 million to 16 million. The solid content of the polyamine flocculant is 40%.
[0016] The strong adsorption sacrificial agent is prepared according to the following method:
[0017] Step 1: add 20 parts of lignin and 90-100 parts of solvent into a reactor by weight to fully dissolve, add 1-4 parts of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 160-200° C., the reaction time to 40-60 min, then immerse the reactor in ice water for rapid cooling and then filter to obtain a filtrate for standby use;
[0018] Step 2, slowly add 20 to 40 parts of epichlorohydrin to the filtrate, adjust the pH to 10 to 11, maintain the temperature at 70 to 90°C, stir at 60 to 80 r / min, and react for 2 to 4 hours;
[0019] Step 3, slowly drop 20 to 40 parts of ethylenediamine, control the temperature at 70 to 80°C, stir at 100 to 120 r / min, react for 1 to 2 hours, and use a rotary evaporator to remove the solvent with a vacuum degree of 0.1 to 0.2 MPa to obtain a strong adsorption sacrificial agent.
[0020] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, with a moisture content of less than 5% and an 80-mesh residue of less than 20%. The solvent is one or more of methanol and ethanol. The catalyst is one of tungstic acid and Co / ZrO2. The microwave power is 500-800W.
[0021] The present invention also provides a method for preparing a machine-made sand modifier containing residual flocculants. According to the above-disclosed machine-made sand modifier containing residual flocculants, the specific composite bacterial population, the activator, and the strong adsorption sacrificial agent are weighed according to the specified weight proportions and then mixed evenly.
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] (1) The present invention adopts the synergistic effect of multiple microorganisms, and cultivates and gradually domesticates the microbial flora, which can avoid the disadvantage that a single microorganism is difficult to adapt to a complex environment, and achieves effective degradation of residual polyacrylamide and polyamine flocculants in machine-made sand. Practice shows that due to trace amounts of residual polyacrylamide, the initial fluidity of concrete is reduced and the loss of fluidity over time increases. Polyamine flocculants, as coagulants, will also have an adverse effect on the workability of concrete, and through interaction with polyacrylamide, the negative impact of polyacrylamide is increased.
[0024] (2) Using methanol / ethanol as the hydrogen supply solvent, the alcoholysis efficiency and delignification degree of lignin were greatly improved by catalyst and microwave-assisted heating under hydrogen-free conditions, thereby increasing the conversion rate of the target products (such as sinapyl alcohol and coniferyl alcohol).
[0025] (3) By introducing epoxy groups and undergoing a ring-opening hydrogenation reaction, the prepared strong adsorption sacrificial agent contains active groups such as ether bonds and amine groups, has the characteristics of a non-ionic surfactant, and can strongly adsorb organic molecules such as flocculants, reduce the "contact" between flocculants and water molecules and water reducers, and hinder their adsorption, thereby releasing the water molecules adsorbed by the flocculant and increasing the free water content in the system.
[0026] (4) The present invention combines the biodegradable residual flocculant with the adsorption sacrificial effect, which can reduce the content and molecular weight of the residual flocculant. At the same time, the sacrificial agent is used to inhibit the binding effect of the flocculant on water molecules, which greatly reduces the adsorption of water by the flocculant, thereby effectively improving the workability of the prepared concrete. DETAILED DESCRIPTION
[0027] The present invention is described in detail below with reference to specific embodiments.
[0028] [Example 1]
[0029] This embodiment contains residual flocculant machine-made sand and workability modifier, and its raw materials include: 30 parts of specific composite bacterial population, 50 parts of activator, and 80 parts of strong adsorption sacrificial agent by weight. Weigh each component according to the specified weight and mix them evenly.
[0030] The activator is obtained by mixing 10% sterile glycerol with a mass fraction and glucose in a ratio of 100:1.
[0031] The specific composite bacterial population of this embodiment is prepared according to the following method:
[0032] Step 1: Take 0.5 parts of Rhodopseudomonas sphaeroides, 0.5 parts of Paracoccus denitrificans and 1 part of Bacillus subtilis respectively, put them into 1000 parts of enrichment culture medium for activation, and culture them at 25° C. and 100 r / min shaking conditions for 24 hours.
[0033] Step 2: Take 50 portions of the culture solution in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture at 25°C and 100 r / min for 2 days. Then add 1 portion of polyamine flocculant and culture at 25°C and 100 r / min for 2 days.
[0034] Step 3: Take 50 parts of the culture solution in step 2 and inoculate them into 1000 parts of the acclimation medium, add 1.5 parts of polyacrylamide, and culture at 25°C and 100 r / min for 2 days. Then add 1.5 parts of polyamine flocculant and culture at 25°C and 100 r / min for 2 days.
[0035] Step 4: Take 50 parts of the culture solution in step 3 and inoculate them into 1000 parts of the acclimation medium, add 2 parts of polyacrylamide, and culture them at 25°C and 100 r / min for 2 days. Then add 2 parts of polyamine flocculant and culture them at 25°C and 100 r / min for 2 days.
[0036] Step 5: Take 50 portions of the culture solution in step 4 and inoculate them into 1000 portions of nutrient culture medium, and culture them at 25° C. and 100 r / min of shaking for 24 hours.
[0037] The enrichment medium is a neutral solution of 5g / L yeast powder, 10g / L tryptone, and 10g / L NaCl. The acclimation medium is a neutral solution of 0.05g / L yeast powder, 0.5g / L NaCl, 1.0g / L K2HPO4, and 0.1g / L MgSO4. The nutrient medium is a neutral solution of 3g / L beef extract, 10g / L peptone, and 5g / L NaCl. The polyacrylamide is an anionic polyacrylamide with a molecular weight of 12 million. The solid content of the polyamine flocculant is 40%.
[0038] The strong adsorption sacrificial agent of this embodiment is prepared according to the following method:
[0039] Step 1: add 20 parts of lignin and 90 parts of solvent into a reactor by weight to fully dissolve, add 1 part of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 160°C, the reaction time to 40 minutes, then immerse the reactor in ice water for rapid cooling and filtering to obtain a filtrate for standby use;
[0040] Step 2: slowly add 20 parts of epichlorohydrin to the filtrate, adjust the pH to 10, maintain the temperature at 70°C, stir at 60r / min, and react for 2h;
[0041] Step 3, slowly drop 20 parts of ethylenediamine, control the temperature at 70°C, stir at 100 r / min, react for 1 hour, use a rotary evaporator to remove the solvent, and the vacuum degree is 0.1 MPa to obtain a strong adsorption sacrificial agent.
[0042] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, the water content is 2%, the residue on 80 mesh is 18%, the solvent is methanol, the catalyst is tungstic acid, and the microwave power is 500W.
[0043] [Example 2]
[0044] This embodiment contains residual flocculant machine-made sand and workability modifier, and its raw materials include: 50 parts of specific composite bacterial population, 80 parts of activator, and 100 parts of strong adsorption sacrificial agent by weight. Each component is weighed according to the specified weight and mixed evenly.
[0045] The activator is obtained by mixing 10% sterile glycerol with a mass fraction and glucose in a ratio of 100:5.
[0046] The specific composite bacterial population of this embodiment is prepared according to the following method:
[0047] Step 1: Take 1 part of Rhodopseudomonas sphaeroides, 0.5 part of Ralstonia piezoelectrica, 1 part of Paracoccus denitrificans and 2 parts of Bacillus subtilis respectively, according to weight, put them into 1000 parts of enrichment culture medium for activation, and culture them at 30° C. and 120 r / min shaking conditions for 48 hours.
[0048] Step 2: Take 50 portions of the culture solution in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture at 30°C and 120 r / min for 3 days. Then add 1 portion of polyamine flocculant and culture at 30°C and 120 r / min for 3 days.
[0049] Step 3: Take 50 parts of the culture solution in step 2 and inoculate them into 1000 parts of the acclimation medium, add 1.5 parts of polyacrylamide, and culture at 30°C and 120 r / min for 3 days. Then add 1.5 parts of polyamine flocculant and culture at 30°C and 120 r / min for 3 days.
[0050] Step 4: Take 50 parts of the culture solution in step 3 and inoculate them into 1000 parts of the acclimation medium, add 2 parts of polyacrylamide, and culture them at 30°C and 120 r / min for 3 days. Then add 2 parts of polyamine flocculant and culture them at 30°C and 120 r / min for 3 days.
[0051] Step 5: Take 50 portions of the culture solution in step 4 and inoculate them into 1000 portions of nutrient culture medium, and culture them at 30° C. and 120 r / min of shaking for 48 hours.
[0052] The enrichment medium is a neutral solution of 5g / L yeast powder, 10g / L tryptone, and 10g / L NaCl, the acclimation medium is a neutral solution of 0.05g / L yeast powder, 0.5g / L NaCl, 1.0g / L K2HPO4, and 0.1g / L MgSO4, and the nutrient medium is a neutral solution of 3g / L beef extract, 10g / L peptone, and 5g / L NaCl. The polyacrylamide is a cationic polyacrylamide, and the solid content of the polyamine flocculant is 40%.
[0053] The strong adsorption sacrificial agent of this embodiment is prepared according to the following method:
[0054] Step 1: add 20 parts of lignin and 100 parts of solvent into a reactor by weight to fully dissolve, add 4 parts of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 200°C, the reaction time to 60 minutes, then immerse the reactor in ice water for rapid cooling and then filter to obtain a filtrate for standby use;
[0055] Step 2: slowly add 40 parts of epichlorohydrin to the filtrate, adjust the pH to 11, maintain the temperature at 90°C, stir at 80r / min, and react for 4h;
[0056] Step 3, slowly drop 40 parts of ethylenediamine, control the temperature at 80°C, stir at 120r / min, react for 2h, use a rotary evaporator to remove the solvent, and the vacuum degree is 0.2MPa to obtain a strong adsorption sacrificial agent.
[0057] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, the water content is 3%, the residue on 80 mesh is 15%, the solvent is ethanol, the catalyst is Co / ZrO2, and the microwave power is 800W.
[0058] [Example 3]
[0059] This embodiment contains residual flocculant machine-made sand and workability modifier, and its raw materials include: 40 parts of specific composite bacterial population, 65 parts of activator, and 90 parts of strong adsorption sacrificial agent by weight. Weigh each component according to the specified weight and mix them evenly.
[0060] The activator is obtained by mixing 10% sterile glycerol and glucose in a ratio of 100:2.5.
[0061] The specific composite bacterial population of this embodiment is prepared according to the following method:
[0062] Step 1: Take 0.75 parts of Rhodopseudomonas sphaeroides, 0.5 parts of Ralstonia piezoelectrica, 1 part of Paracoccus denitrificans and 2 parts of Bacillus subtilis respectively, put them into 1000 parts of enrichment culture medium for activation, and culture them at 28° C. and 110 r / min shaking conditions for 36 hours.
[0063] Step 2: Take 50 portions of the culture solution in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture at 28°C and 110 r / min for 2 days. Then add 1 portion of polyamine flocculant and culture at 28°C and 110 r / min for 2 days.
[0064] Step 3: Take 50 parts of the culture solution in step 2 and inoculate them into 1000 parts of the acclimation medium, add 1.5 parts of polyacrylamide, and culture at 28°C and 110 r / min for 2 days. Then add 1.5 parts of polyamine flocculant and culture at 28°C and 110 r / min for 2 days.
[0065] Step 4: Take 50 parts of the culture solution in step 3 and inoculate them into 1000 parts of the acclimation medium, add 2 parts of polyacrylamide, and culture them at 28°C and 110 r / min for 2 days. Then add 2 parts of polyamine flocculant and culture them at 28°C and 110 r / min for 2 days.
[0066] Step 5: Take 50 portions of the culture solution in step 4 and inoculate them into 1000 portions of nutrient culture medium, and culture them at 28° C. and 110 r / min of shaking for 36 hours.
[0067] The enrichment medium is a neutral solution of 5g / L yeast powder, 10g / L tryptone, and 10g / L NaCl. The acclimation medium is a neutral solution of 0.05g / L yeast powder, 0.5g / L NaCl, 1.0g / L K2HPO4, and 0.1g / L MgSO4. The nutrient medium is a neutral solution of 3g / L beef extract, 10g / L peptone, and 5g / L NaCl. The polyacrylamide is an anionic polyacrylamide with a molecular weight of 16 million. The solid content of the polyamine flocculant is 40%.
[0068] The strong adsorption sacrificial agent of this embodiment is prepared according to the following method:
[0069] Step 1: add 20 parts of lignin and 95 parts of solvent into a reactor by weight to fully dissolve, add 2 parts of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 180°C, the reaction time to 50 minutes, then immerse the reactor in ice water for rapid cooling and filtering to obtain a filtrate for standby use;
[0070] Step 2: slowly add 30 parts of epichlorohydrin to the filtrate, adjust the pH to 10.5, maintain the temperature at 80°C, stir at 70r / min, and react for 3h;
[0071] Step 3, slowly drop 30 parts of ethylenediamine, control the temperature to 75°C, stir at 110 r / min, react for 1.5 h, and use a rotary evaporator to remove the solvent with a vacuum degree of 0.1 MPa to obtain a strong adsorption sacrificial agent.
[0072] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, with a water content of 3%, an 80-mesh sieve residue of 15%, a solvent of methanol, a catalyst of tungstic acid, and a microwave power of 650W.
[0073] [Example 4]
[0074] This embodiment contains residual flocculant machine-made sand and workability modifier, and its raw materials include: 30 parts of specific composite bacterial population, 80 parts of activator, and 100 parts of strong adsorption sacrificial agent by weight. Each component is weighed according to the specified weight and mixed evenly.
[0075] The activator is obtained by mixing 10% sterile glycerol with a mass fraction and glucose in a ratio of 100:5.
[0076] The specific composite bacterial population of this embodiment is prepared according to the following method:
[0077] Step 1: Take 0.5 parts of Rhodopseudomonas sphaeroides, 0.5 parts of Ralstonia piezoelectrica, 1 part of Paracoccus denitrificans and 2 parts of Bacillus subtilis respectively, put them into 1000 parts of enrichment culture medium for activation, and culture them at 25° C. and 100 r / min shaking conditions for 24 hours.
[0078] Step 2: Take 50 portions of the culture solution in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture at 25°C and 100 r / min for 2 days. Then add 1 portion of polyamine flocculant and culture at 25°C and 100 r / min for 2 days.
[0079] Step 3: Take 50 parts of the culture solution in step 2 and inoculate them into 1000 parts of the acclimation medium, add 1.5 parts of polyacrylamide, and culture at 25°C and 100 r / min for 2 days. Then add 1.5 parts of polyamine flocculant and culture at 25°C and 100 r / min for 2 days.
[0080] Step 4: Take 50 parts of the culture solution in step 3 and inoculate them into 1000 parts of the acclimation medium, add 2 parts of polyacrylamide, and culture them at 25°C and 100 r / min for 2 days. Then add 2 parts of polyamine flocculant and culture them at 25°C and 100 r / min for 2 days.
[0081] Step 5: Take 50 portions of the culture solution in step 4 and inoculate them into 1000 portions of nutrient culture medium, and culture them at 25° C. and 100 r / min of shaking for 48 hours.
[0082] The enrichment medium is a neutral solution of 5g / L yeast powder, 10g / L tryptone, and 10g / L NaCl, the acclimation medium is a neutral solution of 0.05g / L yeast powder, 0.5g / L NaCl, 1.0g / L K2HPO4, and 0.1g / L MgSO4, and the nutrient medium is a neutral solution of 3g / L beef extract, 10g / L peptone, and 5g / L NaCl. The polyacrylamide is a cationic polyacrylamide, and the solid content of the polyamine flocculant is 40%.
[0083] The strong adsorption sacrificial agent of this embodiment is prepared according to the following method:
[0084] Step 1: add 20 parts of lignin and 90 parts of solvent into a reactor by weight to fully dissolve, add 1 part of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 200°C, the reaction time to 40 minutes, then immerse the reactor in ice water for rapid cooling and filter, and obtain a filtrate for stand-by use;
[0085] Step 2: slowly add 20 parts of epichlorohydrin to the filtrate, adjust the pH to 10, maintain the temperature at 70°C, stir at 60r / min, and react for 2h;
[0086] Step 3, slowly drop 20 parts of ethylenediamine, control the temperature at 70°C, stir at 100 r / min, react for 1 hour, use a rotary evaporator to remove the solvent, and the vacuum degree is 0.1 MPa to obtain a strong adsorption sacrificial agent.
[0087] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, the water content is 4%, the residue on 80 mesh is 18%, the solvent is ethanol, the catalyst is Co / ZrO2, and the microwave power is 800W.
[0088] [Example 5]
[0089] This embodiment contains residual flocculant machine-made sand and workability modifier, and its raw materials include: 50 parts of specific composite bacterial population, 50 parts of activator, and 80 parts of strong adsorption sacrificial agent by weight. Each component is weighed according to the specified weight and mixed evenly.
[0090] The activator is obtained by mixing 10% sterile glycerol with a mass fraction and glucose in a ratio of 100:1.
[0091] The specific composite bacterial population of this embodiment is prepared according to the following method:
[0092] Step 1: Take 1 part of Rhodopseudomonas sphaeroides, 0.5 part of Ralstonia piezoelectrica, 1 part of Paracoccus denitrificans and 2 parts of Bacillus subtilis respectively, according to weight, put them into 1000 parts of enrichment culture medium for activation, and culture them at 30° C. and 120 r / min shaking conditions for 48 hours.
[0093] Step 2: Take 50 portions of the culture solution in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture at 30°C and 120 r / min for 3 days. Then add 1 portion of polyamine flocculant and culture at 30°C and 120 r / min for 2 to 3 days.
[0094] Step 3: Take 50 parts of the culture solution in step 2 and inoculate them into 1000 parts of the acclimation medium, add 1.5 parts of polyacrylamide, and culture at 30°C and 120 r / min for 3 days. Then add 1.5 parts of polyamine flocculant and culture at 30°C and 120 r / min for 3 days.
[0095] Step 4: Take 50 parts of the culture solution in step 3 and inoculate them into 1000 parts of the acclimation medium, add 2 parts of polyacrylamide, and culture them at 30°C and 120 r / min for 3 days. Then add 2 parts of polyamine flocculant and culture them at 30°C and 120 r / min for 3 days.
[0096] Step 5: Take 50 portions of the culture solution in step 4 and inoculate them into 1000 portions of nutrient culture medium, and culture them at 30° C. and 120 r / min of shaking for 24 hours.
[0097] The enrichment medium is a neutral solution of 5g / L yeast powder, 10g / L tryptone, and 10g / L NaCl. The acclimation medium is a neutral solution of 0.05g / L yeast powder, 0.5g / L NaCl, 1.0g / L K2HPO4, and 0.1g / L MgSO4. The nutrient medium is a neutral solution of 3g / L beef extract, 10g / L peptone, and 5g / L NaCl. The polyacrylamide is an anionic polyacrylamide with a molecular weight of 14 million and a polyamine flocculant solid content of 40%.
[0098] The strong adsorption sacrificial agent of this embodiment is prepared according to the following method:
[0099] Step 1: add 20 parts of lignin and 100 parts of solvent into a reactor by weight to fully dissolve, add 3 parts of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 160° C., the reaction time to 50 min, then immerse the reactor in ice water for rapid cooling and then filter to obtain a filtrate for standby use;
[0100] Step 2: slowly add 30 parts of epichlorohydrin to the filtrate, adjust the pH to 11, maintain the temperature at 80°C, stir at 70r / min, and react for 3h;
[0101] Step 3, slowly drop 30 parts of ethylenediamine, control the temperature to 75°C, stir at 110r / min, react for 1h, use a rotary evaporator to remove the solvent, and the vacuum degree is 0.2MPa to obtain a strong adsorption sacrificial agent.
[0102] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, the water content is 4%, the residue on 80 mesh is 17%, the solvent is methanol, the catalyst is tungstic acid, and the microwave power is 500W.
[0103] [Example 6]
[0104] This embodiment contains residual flocculant machine-made sand and workability modifier, and its raw materials include: 40 parts of specific composite bacterial population, 65 parts of activator, and 90 parts of strong adsorption sacrificial agent by weight. Weigh each component according to the specified weight and mix them evenly.
[0105] The activator is obtained by mixing 10% sterile glycerol and glucose in a ratio of 100:2.5.
[0106] The specific composite bacterial population of this embodiment is prepared according to the following method:
[0107] Step 1: Take 0.5 parts of Rhodopseudomonas sphaeroides, 0.5 parts of Ralstonia piezoelectrica, 0.5 parts of Paracoccus denitrificans and 1 part of Bacillus subtilis respectively, put them into 1000 parts of enrichment culture medium for activation, and culture them at 30° C. and 120 r / min shaking conditions for 48 hours.
[0108] Step 2: Take 50 portions of the culture solution in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture at 25°C and 100 r / min for 3 days. Then add 1 portion of polyamine flocculant and culture at 25°C and 100 r / min for 3 days.
[0109] Step 3: Take 50 parts of the culture solution in step 2 and inoculate them into 1000 parts of the acclimation medium, add 1.5 parts of polyacrylamide, and culture at 25°C and 100 r / min for 3 days. Then add 1.5 parts of polyamine flocculant and culture at 25°C and 100 r / min for 3 days.
[0110] Step 4: Take 50 parts of the culture solution in step 3 and inoculate them into 1000 parts of the acclimation medium, add 2 parts of polyacrylamide, and culture them at 25°C and 100 r / min for 2 days. Then add 2 parts of polyamine flocculant and culture them at 25°C and 100 r / min for 2 days.
[0111] Step 5: Take 50 portions of the culture solution in step 4 and inoculate them into 1000 portions of nutrient culture medium, and culture them at 30° C. and 120 r / min of shaking for 36 hours.
[0112] The enrichment medium is a neutral solution of 5g / L yeast powder, 10g / L tryptone, and 10g / L NaCl, the acclimation medium is a neutral solution of 0.05g / L yeast powder, 0.5g / L NaCl, 1.0g / L K2HPO4, and 0.1g / L MgSO4, and the nutrient medium is a neutral solution of 3g / L beef extract, 10g / L peptone, and 5g / L NaCl. The polyacrylamide is a cationic polyacrylamide, and the solid content of the polyamine flocculant is 40%.
[0113] The strong adsorption sacrificial agent of this embodiment is prepared according to the following method:
[0114] Step 1: add 20 parts of lignin and 100 parts of solvent into a reactor by weight to fully dissolve, add 4 parts of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 200°C, the reaction time to 50 minutes, then immerse the reactor in ice water for rapid cooling and then filter to obtain a filtrate for standby use;
[0115] Step 2: slowly add 30 parts of epichlorohydrin to the filtrate, adjust the pH to 11, maintain the temperature at 90°C, stir at 80r / min, and react for 4h;
[0116] Step 3, slowly drop 40 parts of ethylenediamine, control the temperature to 75°C, stir at 110 r / min, react for 1 h, use a rotary evaporator to remove the solvent, and the vacuum degree is 0.2 MPa to obtain a strong adsorption sacrificial agent.
[0117] The lignin is prepared by extracting papermaking black liquor by acid precipitation method, the water content is 3%, the residue on 80 mesh is 16%, the solvent is ethanol, the catalyst is Co / ZrO2, and the microwave power is 650W.
[0118] [Comparative Example 1]
[0119] The composition and preparation method of Comparative Example 1 are basically the same as those of Example 1, except that: during the preparation of the specific composite bacterial population, no polyamine flocculant is added in steps 2 to 4.
[0120] [Comparative Example 2]
[0121] The composition and preparation method of Comparative Example 2 are basically the same as those of Example 1, except that: during the preparation of the specific composite bacterial population, the culture is carried out in the nutrient medium for 20 hours in step five.
[0122] [Comparative Example 3]
[0123] The composition and preparation method of Comparative Example 3 are basically the same as those of Example 1, except that: during the preparation of the strong adsorption sacrificial agent, high-purity nitrogen is not filled into the reactor in step 1, and the reactor is filled with air.
[0124] [Comparative Example 4]
[0125] The composition and preparation method of Comparative Example 4 are substantially the same as those of Example 1, except that no catalyst is added in step 1 during the preparation of the strong adsorption sacrificial agent.
[0126] [Comparative Example 5]
[0127] The composition and preparation method of Comparative Example 5 are basically the same as those of Example 1, except that: during the preparation of the strong adsorption sacrificial agent, the microwave power in step 1 is 400W.
[0128] The machine-made sand and workability modifier prepared in Examples 1 to 6 and Comparative Examples 1 to 5 were added to the machine-made sand containing flocculant (the flocculant was a polyacrylamide / polyamine composite flocculant, and the content was 0.04% of the dry mass of the machine-made sand) at a rate of 0.02% (mass fraction), and the concrete performance test was carried out after natural stacking for 7 days, and untreated machine-made sand was used as a comparison. The concrete mix ratio used is shown in Table 1. The cement is PO42.5 cement, the fly ash is Class II ash, the mud content of 5-16 mm crushed stone and 16-25 mm crushed stone is 0.6% and 0.5% respectively, the mixing water is tap water, and the polycarboxylic acid water reducer is used, and the mixing amount is 1.0%. The slump, expansion and time loss of fresh concrete were tested in accordance with GB / T 50080-2016 “Standard Test Methods for Performance of Ordinary Concrete Mixtures”, and the compressive strength of concrete was tested in accordance with GB / T 50081-2019 “Standard Test Methods for Physical and Mechanical Properties of Concrete”. The results are shown in Table 2.
[0129] Table 1 Concrete mix ratio (kg / m 3 ):
[0130] cement Fly ash Machine-made sand 5-16 mm gravel 16~25mm gravel water Water reducing agent 320 80 761 315 736 164 4
[0131] Table 2 Concrete performance test results:
[0132]
[0133]
[0134] As can be seen from Table 2, the machine-made sand and workability modifier provided by the present invention can overcome the adverse effects of residual flocculants in machine-made sand on the fluidity of concrete. When untreated machine-made sand is used to mix concrete, the slump of concrete cannot meet the construction requirements. After being treated with the machine-made sand and workability modifier prepared in Examples 1 to 6, the initial fluidity of the mixed concrete is significantly better than the benchmark, and the loss over time is very small, the workability of the concrete is greatly improved, and the 28d compressive strength is also slightly higher than the benchmark. Compared with Example 1, no polyamine flocculant is added in Steps 2 to 4 of Comparative Example 1, so the specific composite bacterial population lacks the ability to degrade the polyamine flocculant, resulting in reduced fluidity. In the preparation process of the heterosexual composite bacterial population in Comparative Example 2, the culture in the nutrient culture medium in Step 5 is relatively short, so the number of strains is insufficient, which also affects the degradation ability of the flocculant. In the preparation process of the strong adsorption sacrificial agent in Comparative Example 3, high-purity nitrogen is not filled into the reactor in Step 1, and the degree of alcoholysis of lignin in the air environment is insufficient, thus affecting the effect of the sacrificial agent. In the preparation process of the strong adsorption sacrificial agent in Comparative Example 4, no catalyst was added in step 1, which affected the decomposition degree of lignin and the effect of the sacrificial agent. In the preparation process of the strong adsorption sacrificial agent in Comparative Example 5, the microwave power in step 1 was low, the decomposition degree of lignin was low, which affected the effect of the sacrificial agent, and thus the fluidity of the concrete was low. The concrete workability in Comparative Examples 1 to 5 was average, and the 28d compressive strength was lower than that in Example 1.
[0135] Although the present invention is described by way of embodiments, the embodiments are not intended to limit the present invention. Those skilled in the art may make various modifications and improvements within the spirit of the present invention, such as adjustment of the composition ratio or time range, and the effect after such adjustment is predictable, so it is also within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope defined by the same or equivalent technical features of the claims of this application.
Claims
1. A machine-made sand modifier containing residual flocculant, characterized in that: The composition comprises, by weight: 30 to 50 parts of specific composite bacterial population, 50 to 80 parts of activator, and 80 to 100 parts of strong adsorption sacrificial agent; The residual flocculant includes one or two of polyacrylamide or polyacrylamide / polyamine composite flocculants, and the activator is obtained by mixing 10% sterile glycerol with glucose in a ratio of 100:(1-5).
2. The residual flocculant-containing machine-made sand modifier according to claim 1, characterized in that: The specific composite bacterial population is prepared according to the following method: Step 1: taking 0.5-1 parts of Rhodopseudomonas sphaeroides, 0-0.5 parts of Ralstonia piezoelectrica, 0.5-1 parts of Paracoccus denitrificans and 1-2 parts of Bacillus subtilis respectively by weight and putting them into 1000 parts of enrichment medium for activation, and culturing them at 25-30° C. and 100-120 r / min of shaking conditions for 24-48 hours to obtain culture solution A; Step 2: Take 50 portions of the culture solution A in step 1 and inoculate them into 1000 portions of the acclimation medium, add 1 portion of polyacrylamide, and culture them at 25-30° C. and 100-120 r / min for 2-3 days; then add 1 portion of polyamine flocculant, and culture them at 25-30° C. and 100-120 r / min for 2-3 days to obtain culture solution B; Step 3, take 50 parts of the culture solution B in step 2 and inoculate them into 1000 parts of the acclimation medium, and add 1.5 parts of polyacrylamide, and culture them at 25-30° C. and 100-120 r / min for 2-3 days; then add 1.5 parts of polyamine flocculant, and culture them at 25-30° C. and 100-120 r / min for 2-3 days to obtain culture solution C; Step 4: Take 50 portions of the culture solution C in step 3 and inoculate them into 1000 portions of the acclimation medium, add 2 portions of polyacrylamide, and culture them at 25-30° C. and 100-120 r / min for 2-3 days; then add 2 portions of polyamine flocculant, and culture them at 25-30° C. and 100-120 r / min for 2-3 days to obtain culture solution D; Step 5: Take 50 portions of the culture solution D in step 4 and inoculate them into 1000 portions of nutrient medium, and culture them at 25-30° C. and 100-120 r / min of shaking conditions for 24-48 hours to obtain a specific composite bacterial population.
3. The method for preparing a specific composite bacterial population according to claim 2, characterized in that: The enrichment medium is a neutral solution of 5 g / L yeast powder, 10 g / L tryptone, and 10 g / L NaCl, the acclimation medium is a neutral solution of 0.05 g / L yeast powder, 0.5 g / L NaCl, 1.0 g / L K2HPO4, and 0.1 g / L MgSO4, and the nutrient medium is a neutral solution of 3 g / L beef extract, 10 g / L peptone, and 5 g / L NaCl.
4. The method for preparing a specific composite bacterial population according to claim 2, characterized in that: The polyacrylamide is one of anionic polyacrylamide and cationic polyacrylamide, and has a molecular weight of 12 million to 16 million.
5. The method for preparing a specific composite bacterial population according to claim 2, characterized in that: The solid content of the polyamine flocculant is 40%.
6. The machine-made sand modifier containing residual flocculant according to claim 1, characterized in that: The strong adsorption sacrificial agent is prepared according to the following method: Step 1: add 20 parts of lignin and 90-100 parts of solvent into a reactor by weight to fully dissolve, add 1-4 parts of catalyst, fill the reactor with high-purity nitrogen to exclude air, then put the reactor into a microwave digestion instrument, set the temperature to 160-200° C., the reaction time to 40-60 min, then immerse the reactor in ice water for rapid cooling and then filter to obtain a filtrate for standby use; Step 2, slowly add 20 to 40 parts of epichlorohydrin to the filtrate, adjust the pH to 10 to 11, maintain the temperature at 70 to 90°C, stir at 60 to 80 r / min, and react for 2 to 4 hours; Step 3, slowly drop 20 to 40 parts of ethylenediamine, control the temperature at 70 to 80°C, stir at 100 to 120 r / min, react for 1 to 2 hours, and use a rotary evaporator to remove the solvent with a vacuum degree of 0.1 to 0.2 MPa to obtain a strong adsorption sacrificial agent.
7. The method for preparing a strong adsorption sacrificial agent according to claim 6, characterized in that: The lignin is prepared by extracting papermaking black liquor by acid precipitation method, with a moisture content of less than 5% and an 80-mesh residue of less than 20%. The solvent is one or more of methanol and ethanol. The catalyst is one of tungstic acid and Co / ZrO2. The microwave power is 500-800W.
8. A method for preparing a machine-made sand modifier containing residual flocculant, characterized in that: According to the residual flocculant machine-made sand modifier according to claims 1 to 7, the specific composite bacterial population, the activator, and the strong adsorption sacrificial agent are weighed according to the specified weight parts and then mixed evenly.