Modified lime powder as well as preparation method and application thereof

Abstract

The invention discloses modified lime powder and a preparation method and application thereof.The modified lime powder comprises lime powder and a modifier, the modifier comprises silicate, a titanate composite coupling agent and a microbial flocculant, the mass ratio of the lime powder to the silicate is 1: (5%-15%), and the mass ratio of the silicate to the microbial flocculant is 1: (5%-15%). The mass of the titanate composite coupling agent is 0.5%-1.0% of the sum of the mass of the lime powder and the silicate, and the mass of the microbial flocculant is 0.2-1 time of the sum of the mass of the lime powder, the silicate and the titanate composite coupling agent. The invention aims to obtain a modified lime material which plays a green and environment-friendly role in sewage treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of environmentally friendly materials, and in particular to modified lime powder, a preparation method and application thereof. Background Art

[0002] my country's Water Pollution Prevention and Control Law stipulates that sewage discharged from dispersed population centers, such as residential areas, tourist attractions, resorts, sanatoriums, airports, railway stations, and economic development zones, and industrial wastewater from independent industrial and mining areas, which cannot be included in the urban sewage collection system, must be treated on-site to meet discharge standards. Discharging untreated wastewater into rivers and streams can cause serious harm, such as eutrophication, impacting water sources, increasing water treatment costs, and endangering human and biological survival. Existing wastewater treatment systems require high investment and operating costs. Summary of the Invention

[0003] The main purpose of the present invention is to provide a modified lime powder and a preparation method and application thereof, aiming to solve the problem in the prior art that there is still a lack of modified lime materials that play a green and environmentally friendly role in sewage treatment.

[0004] To achieve the above object, the present invention provides a modified lime powder, which comprises lime powder and a modifier, wherein the modifier comprises silicate, titanate composite coupling agent and microbial flocculant.

[0005] Optionally, the mass ratio of the lime powder and the silicate is 1:(5%-15%), the mass of the titanate composite coupling agent is 0.5%-1.0% of the sum of the masses of the lime powder and the silicate, and the mass of the microbial flocculant is 0.2 to 1 times the sum of the masses of the lime powder, silicate and the titanate composite coupling agent.

[0006] Optionally, the mass ratio of the lime powder and the silicate is 1:10%, the mass of the titanate composite coupling agent is 0.7% of the sum of the masses of the lime powder and the silicate, and the mass of the microbial flocculant is 0.5 times the sum of the masses of the lime powder, silicate and the titanate composite coupling agent.

[0007] Optionally, the microbial flocculant includes at least one of AJ7002 microbial flocculant, PF101 flocculant and NOC1 flocculant, preferably AJ7002 microbial flocculant.

[0008] Optionally, the silicate includes at least one of aluminum silicate, iron silicate, calcium silicate, magnesium silicate, potassium silicate and sodium silicate, preferably aluminum silicate and iron silicate.

[0009] Optionally, the mass ratio of aluminum silicate to ferric silicate is 1:2-5, preferably the mass ratio of aluminum silicate to ferric silicate is 1:3.

[0010] Optionally, the titanate composite coupling agent comprises, by mass, 25%-30% active silicon dioxide, 0.5%-2% citric acid additive, 2%-4% tributyl titanium oxide, and the balance ethanol.

[0011] Optionally, the titanate composite coupling agent comprises, by mass, 27% active silicon dioxide, 1% citric acid additive, 3% tributyl titanium oxide, and the balance ethanol.

[0012] To achieve the above object, the present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0013] Step S1, calcining and crushing raw limestone ore and sieving to obtain initial lime powder, adding 5% to 15% by weight of silicate to the initial lime powder, and stirring to obtain lime mixture 1;

[0014] Step S2, slowly adding 0.5%-1.0% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2;

[0015] Step S3, drying and calcining the lime mixture 2 to obtain a dry mixture 3;

[0016] Step S4, adding 0.2-1 times the mass of the total mass of the dry mixture 3 to the dry mixture 3 to obtain a mixture 4;

[0017] Step S5: vacuum ball milling the mixture 4 to obtain the target modified lime powder 1.

[0018] A method for preparing the modified lime powder comprises the following steps:

[0019] Step S1, calcining and crushing raw limestone ore and sieving to obtain initial lime powder, adding silicate in an amount of 10% by weight of the initial lime powder to the initial lime powder, and stirring to obtain lime mixture 1;

[0020] Step S2, slowly adding 0.7% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2;

[0021] Step S3, drying and calcining the lime mixture 2 to obtain a dry mixture 3;

[0022] Step S4, adding a microbial flocculant in an amount of 0.5 times the total mass of the dry mixture 3 to the dry mixture 3, and mixing to obtain a mixture 4;

[0023] Step S5: vacuum ball milling the mixture 4 to obtain the target modified lime powder 1.

[0024] Optionally, the step S1 specifically includes calcining and crushing the raw limestone ore and then passing it through a 70-90 mesh sieve to obtain initial lime powder, wherein the mass percentage of calcium oxide in the initial lime powder is 90% to 100%.

[0025] Optionally, the titanate composite coupling agent in step S2 is prepared from 25%-30% by weight of active silica, 0.5%-2% by weight of a citric acid additive, 2%-4% by weight of tributyl titanium oxide, and the balance being an ethanol solvent.

[0026] Optionally, the titanate composite coupling agent in step S2 is prepared from 27% by mass of active silicon dioxide, 1% by mass of a citric acid additive, 3% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0027] Optionally, the microbial flocculant in step S4 is AJ7002 microbial flocculant, and its mass is 0.2-1 times the sum of the masses of the lime powder, silicate and titanate composite coupling agent.

[0028] Optionally, the microbial flocculant in step S4 is AJ7002 microbial flocculant, and its mass is 0.5 times the sum of the masses of the lime powder, silicate and titanate composite coupling agent.

[0029] Optionally, the step S5 specifically includes placing the mixture 4 in a ball milling device, and exhausting the air in the ball milling device by a vacuum pump, controlling the rotation speed of the ball mill to 200-400 rpm, and the ball milling time to 2-7 hours.

[0030] Optionally, the step S5 specifically includes placing the mixture 4 in a ball milling device, and exhausting the air in the ball milling device by a vacuum pump, controlling the rotation speed of the ball mill to 300 rpm, and the ball milling time to 5 hours.

[0031] In addition, in order to achieve the above-mentioned purpose, the present invention provides the modified lime powder or the modified limestone powder obtained by the preparation method, which plays a green and environmentally friendly application in sewage treatment.

[0032] Beneficial effects

[0033] (1) The present invention proposes a modified lime powder, which can enhance the intimacy between lime particles by adding aluminum silicate and iron silicate to lime, increase the coverage area and reduce the water absorption rate of lime, thereby alleviating the water absorption and agglomeration of lime when exposed to air, thereby facilitating its preservation.

[0034] (2) Both aluminum silicate and ferric silicate can be used as coagulants. During the water treatment process, they can promote the aggregation of suspended particles in the water to form larger flocs, thereby accelerating the sedimentation of particles and achieving solid-liquid separation. In some cases, aluminum silicate and ferric silicate can be combined with other coagulants to form complexes, enhancing the coagulation effect and increasing the removal rate of suspended matter. This auxiliary coagulation effect helps to improve the operating efficiency of the water treatment system. Aluminum silicate and ferric silicate have certain bactericidal and algae-inhibiting effects, which can effectively reduce the number of algae and keep the water clean and healthy. This is particularly important for preventing the deterioration of water quality caused by excessive algae growth.

[0035] (3) Add titanate composite coupling agent, the functional group of titanate can react with the Ca in lime 2+ Ion binding, and through redox reaction to form a stable interpenetrating network structure, forming hydrophobic functional groups on the surface of lime, and generating some Ti 4+ ions and hydroxide ions OH - , strengthening the adhesion between lime particles. In wastewater treatment, adsorbents are often used to remove pollutants from water. Titanate composite coupling agents can enhance the binding force between adsorbents and pollutants, thereby improving adsorption efficiency.

[0036] (4) Adding microbial flocculants can first adsorb and coagulate tiny particles in sewage, and then remove them by sedimentation or filtration. The COD removal rate is high, which not only improves the treatment efficiency but also reduces the use of chemicals, which is conducive to reducing operating costs. DETAILED DESCRIPTION

[0037] Example 1.

[0038] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0039] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder. A silicate is added to the initial lime powder at a concentration of 10% by weight of the initial lime powder, and the mixture is stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:3.

[0040] Step S2: slowly adding 0.7% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; wherein the titanate composite coupling agent is prepared by 27% by mass of active silica, 1% by mass of a citric acid additive, 3% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0041] Step S3: drying and calcining the lime mixture 2 to obtain a dry mixture 3.

[0042] Step S4, adding a microbial flocculant in an amount of 0.5 times the total mass of the dry mixture 3 to the dry mixture 3, and mixing to obtain a mixture 4;

[0043] Step S5: vacuum ball milling the mixture 4, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 300 rpm, and the ball milling time is 5 hours to obtain the target modified lime powder 1.

[0044] Example 2:

[0045] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0046] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder. A silicate is added to the initial lime powder at a concentration of 5% by weight of the initial lime powder, and the mixture is stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:2.

[0047] Step S2: slowly adding 0.5% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; wherein the titanate composite coupling agent is prepared by 25% by mass of active silica, 0.5% by mass of a citric acid additive, 2% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0048] Step S3: drying and calcining the lime mixture 2 to obtain a dry mixture 3.

[0049] Step S4, adding a microbial flocculant in an amount of 0.2 times the total mass of the dry mixture 3 to the dry mixture 3, and mixing to obtain a mixture 4;

[0050] Step S5: vacuum ball milling the mixture 4, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 200 rpm, and the ball milling time is 2 hours to obtain the target modified lime powder 1.

[0051] Example 3:

[0052] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0053] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder. A silicate is added to the initial lime powder at a concentration of 15% by weight of the initial lime powder, and the mixture is stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:5.

[0054] Step S2: slowly adding 1.0% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; wherein the titanate composite coupling agent is prepared by 30% by mass of active silica, 2% by mass of a citric acid additive, 4% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0055] Step S3: drying and calcining the lime mixture 2 to obtain a dry mixture 3.

[0056] Step S4, adding a microbial flocculant in an amount equal to 1 times the total mass of the dry mixture 3 to the dry mixture 3, and mixing to obtain a mixture 4;

[0057] Step S5: vacuum ball milling the mixture 4, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 400 rpm, and the ball milling time is 7 hours to obtain the target modified lime powder 1.

[0058] Example 4:

[0059] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0060] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder, and a silicate is added to the initial lime powder at a concentration of 3% by weight of the initial lime powder, and the mixture is stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:1.

[0061] Step S2: slowly adding 0.3% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; wherein the titanate composite coupling agent is prepared by 20% by mass of active silica, 0.3% by mass of a citric acid additive, 1% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0062] Step S3: drying and calcining the lime mixture 2 to obtain a dry mixture 3.

[0063] Step S4, adding a microbial flocculant in an amount of 0.1 times the total mass of the dry mixture 3 to the dry mixture 3, and mixing to obtain a mixture 4;

[0064] Step S5: vacuum ball milling the mixture 4, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 100 rpm, and the ball milling time is 1 hour to obtain the target modified lime powder 1.

[0065] Example 5:

[0066] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0067] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder. A silicate in an amount of 20% by weight of the initial lime powder is added to the initial lime powder and stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:6.

[0068] Step S2: slowly adding 2.0% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; wherein the titanate composite coupling agent is prepared by 35% by mass of active silica, 5% by mass of a citric acid additive, 5% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0069] Step S3: drying and calcining the lime mixture 2 to obtain a dry mixture 3.

[0070] Step S4, adding a microbial flocculant twice the mass of the total mass of the dry mixture 3 to the dry mixture 3, and mixing to obtain a mixture 4;

[0071] Step S5: vacuum ball milling the mixture 4, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 500 rpm, and the ball milling time is 10 hours to obtain the target modified lime powder 1.

[0072] Example 6:

[0073] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0074] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder. A silicate is added to the initial lime powder at a concentration of 10% by weight of the initial lime powder, and the mixture is stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:3.

[0075] Step S2: slowly adding 0.7% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; wherein the titanate composite coupling agent is prepared by 27% by mass of active silica, 1% by mass of a citric acid additive, 3% by mass of tributyl titanium oxide, and the remainder of an ethanol solvent.

[0076] Step S3: drying and calcining the lime mixture 2 to obtain a dry mixture 3.

[0077] Step S4: vacuum ball milling the mixture 3, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 300 rpm, and the ball milling time is 5 hours to obtain the target modified lime powder 1.

[0078] Example 7:

[0079] The present invention also provides a method for preparing the modified lime powder, the method comprising the following steps:

[0080] In step S1, limestone ore is calcined, crushed, and sieved to obtain initial lime powder. A silicate is added to the initial lime powder at a concentration of 10% by weight of the initial lime powder, and the mixture is stirred to obtain a lime mixture 1. The lime powder has a calcium oxide content of 85% by weight and is obtained by calcining, crushing, and sieving the limestone ore through a 60-100 mesh sieve. The silicate is aluminum silicate and iron silicate in a mass ratio of 1:3.

[0081] Step S2: drying and calcining the lime mixture 1 to obtain a dry mixture 2.

[0082] Step S3, adding a microbial flocculant in an amount of 0.5 times the total mass of the dry mixture 2 to the dry mixture 2, and mixing to obtain a mixture 3;

[0083] Step S4: vacuum ball milling the mixture 3, and exhausting the air in the ball mill by a vacuum pump. The speed of the ball mill is controlled to be 300 rpm, and the ball milling time is 5 hours to obtain the target modified lime powder 1.

[0084] Example 8:

[0085] According to GB18918-2002 "Pollutant Discharge Standard for Urban Wastewater Treatment Plants", the chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended solids (SS), and ammonia nitrogen content (in terms of N) of the sewage before and after treatment were tested; wherein the target modified lime powder 1 in the embodiment was added to the sewage before treatment to obtain the corresponding treated sewage;

[0086] The specific test data of the experiment are shown in Table 1.

[0087] Table 1 Detection data before and after sewage treatment

[0088]

[0089] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A modified lime powder, comprising lime powder and a modifier, wherein the modifier comprises silicate, titanate composite coupling agent and microbial flocculant.

2. The modified lime powder according to claim 1, characterized in that The mass ratio of the lime powder to the silicate is 1:(5%-15%), the mass of the titanate composite coupling agent is 0.5%-1.0% of the sum of the masses of the lime powder and the silicate, and the mass of the microbial flocculant is 0.2 to 1 times the sum of the masses of the lime powder, the silicate and the titanate composite coupling agent.

3. The modified lime powder according to claim 1, characterized in that The microbial flocculant includes at least one of AJ7002 microbial flocculant, PF101 flocculant and NOC1 flocculant, preferably AJ7002 microbial flocculant.

4. The modified lime powder according to claim 1, characterized in that Optionally, the silicate includes at least one of aluminum silicate, iron silicate, calcium silicate, magnesium silicate, potassium silicate and sodium silicate, preferably aluminum silicate and iron silicate.

5. The modified lime powder according to claim 4, characterized in that The mass ratio of the aluminum silicate to the iron silicate is 1:2-5, and preferably the mass ratio of the aluminum silicate to the iron silicate is 1:

3.

6. The modified lime powder according to claim 1, characterized in that The titanate composite coupling agent comprises, by mass, 25%-30% of active silicon dioxide, 0.5%-2% of a citric acid auxiliary agent, 2%-4% of tributyl titanium oxide and the balance of ethanol.

7. The modified lime powder according to claim 1, characterized in that The titanate composite coupling agent comprises, by mass, 27% active silicon dioxide, 1% citric acid auxiliary agent, 3% tributyl titanium oxide and the balance ethanol.

8. A method for preparing modified lime powder comprises the following steps: Step S1, calcining and crushing raw limestone ore and sieving to obtain initial lime powder, adding 5% to 15% by weight of silicate to the initial lime powder, and stirring to obtain lime mixture 1; Step S2, slowly adding 0.5%-1.0% of the total mass of the lime mixture 1 to the lime mixture 1, and stirring at room temperature for 8-12 hours to obtain a hydrophobic lime mixture 2; Step S3, drying and calcining the lime mixture 2 to obtain a dry mixture 3; Step S4, adding 0.2-1 times the mass of the total mass of the dry mixture 3 to the dry mixture 3 to obtain a mixture 4; Step S5: vacuum ball milling the mixture 4 to obtain the target modified lime powder 1.

9. The method for preparing the modified lime powder according to claim 8, wherein The step S1 specifically includes calcining and crushing the raw limestone ore and then passing it through a 70-90 mesh sieve to obtain initial lime powder, wherein the calcium oxide content of the initial lime powder is 90% to 100% by weight.

10. The method for preparing the modified lime powder according to claim 8, wherein The titanate composite coupling agent in step S2 is prepared from 25%-30% by mass of active silica, 0.5%-2% by mass of citric acid additive, 2%-4% by mass of tributyl titanium oxide, and the balance of ethanol solvent; the microbial flocculant in step S4 is AJ7002 microbial flocculant, the mass of which is 0.2-1 times the sum of the masses of lime powder, silicate, and titanate composite coupling agent; and step S5 specifically includes placing the mixture 4 in a ball mill, exhausting the air in the ball mill by a vacuum pump, controlling the speed of the ball mill to 200-400 rpm, and the ball milling time to 2-7 hours.

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