Composite exciting agent, manganese slag fluid soil and preparation method and application of manganese slag fluid soil

Abstract

The invention belongs to the technical field of manganese slag resource utilization, and particularly relates to a composite exciting agent, manganese slag fluid soil and a preparation method and application of the manganese slag fluid soil. The composite activator comprises mineral powder, lime, cement and a surface modifier. The surface modifier comprises higher phosphate and higher fatty acid salt. The mineral powder, the cement, the lime and the surfactant serve as the composite exciting agent, when the manganese slag is treated, the activity of the manganese slag can be activated, the manganese slag fluid soil with good compressive strength is formed, the manganese slag has the high mixing amount and accounts for 85-95.5% of the total mass of the mixed powder, the purpose of large-scale resource utilization of the manganese slag can be achieved, the environmental pressure is relieved, and the economic benefit is increased. And the method has good economical efficiency. Meanwhile, the surface modifier adopts a specific high-grade phosphate and high-grade fatty acid salt compounding mode, so that the friction force in a composite system can be effectively reduced, the flowability of the composite system is improved, the problem of limited material contact is solved, and the compressive strength is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of manganese slag resource utilization, and particularly relates to a composite activator, manganese slag fluidized soil, and a preparation method and application thereof. Background Art

[0002] In recent years, the pollution problem of electrolytic manganese has become a hot topic of social concern, and the treatment and disposal of manganese slag has become a difficult problem in the treatment of manganese pollution. Most of the existing electrolytic manganese production enterprises still discharge manganese filter press waste slag in the form of stockpiling. During the long-term stockpiling process, it not only occupies a large amount of land, but also has a certain impact on the surrounding environment. How to achieve the harmlessness and resource utilization of manganese slag, recycle and comprehensively utilize manganese slag, turn waste into treasure, and minimize the harm of manganese slag is very important.

[0003] There are currently many methods for solidifying manganese slag, but the processing steps are complicated, the amount of manganese slag used is low (no more than 50%), and the economy is poor; there are also methods for resource utilization of manganese slag using activators, but the strength of the products prepared is low, which cannot meet engineering needs and lacks the basis for large-scale application.

[0004] Therefore, it is of great significance to provide a composite activator which has a high usage of manganese slag and can produce manganese slag fluidized soil with good strength. Summary of the invention

[0005] The present invention aims to solve one or more technical problems existing in the above-mentioned prior art and at least provide a beneficial choice. Specifically, the present invention provides a composite activator, which has a high usage amount of manganese slag when treating manganese slag, and the prepared manganese slag fluidized soil has good compressive strength.

[0006] The inventive concept of the present invention is as follows: the composite activator of the present invention comprises mineral powder, lime, cement, and surface modifier; the surface modifier comprises high-grade phosphate and high-grade fatty acid salt. The main chemical components in manganese slag are calcium sulfate, followed by silicate, aluminate, and a small amount of iron, manganese and ionic ammonium. During the hydration process, 3CaO·SiO2 (C3S) in cement rapidly hydrolyzes to release Ca(OH)2, and the added lime can make Ca(OH)2 dissolve the glass in the mineral powder and manganese slag, stimulating the activity of the mineral powder and manganese slag; the addition of lime can also increase the supersaturation of Ca(OH)2, and Ca(OH)2 crystals will precipitate in advance, thereby shortening the induction period. C3A in the solution (water added during the application of the composite activator to dissolve the ions in part of the powder (mineral powder, lime, cement, surface modifier and manganese slag)) rapidly hydrates, and in the presence of calcium sulfate, calcium sulfonate is formed, which drives the consumption of iron and aluminum ions, and the crystals gradually increase, and then are converted into monosulfur hydrated calcium aluminum sulfate (ferrite). As the hydration products increase, they fill the space originally occupied by water to form a material with a certain strength. At the same time, the surface modifier adopts a specific high-grade phosphate and high-grade fatty acid salt compound, which can effectively reduce the friction in the composite system, improve the fluidity of the composite system, solve the problem of limited material contact, and improve the compressive strength.

[0007] The reaction equation involved is as follows:

[0008] 3CaO·SiO2+nH2O=xCaO·SiO2·yH2O+(3-x)Ca(OH)2;

[0009] 2CaO·SiO2+mH2O=xCaO·SiO2·yH2O+(2-x)Ca(OH)2;

[0010] 4CaO·Al2O3·13H2O+3(CaSO4·2H2O)+14H2O=3CaO·Al2O3·3CaSO4·32H2O+Ca(OH)2;

[0011] 3CaO·Al2O3·3CaSO4·32H2O+2(CaO·Al2O3·13H2O)=3(3CaO·Al2O3·CaSO4·12H2O)+

[0012] 2Ca(OH)2+20H2O;

[0013] 4CaO·Al2O3·Fe2O3+2Ca(OH)2+6(CaSO4·2H2O)+50H2O=2[4CaO·(Al2O3·Fe2O3)·3CaSO4·32H2O];

[0014] 2[4CaO·(Al2O3·Fe2O3)·13H2O]+4CaO·(Al2O3·Fe2O3)·3CaSO4·32H2O=3[3CaO·(Al2O3·Fe2O3)·CaSO4·12H2O]+2Ca(OH)2+20H2O.

[0015] Therefore, a first aspect of the present invention provides a composite activator.

[0016] Specifically, the composite activator includes mineral powder, lime, cement, and surface modifier;

[0017] The surface modifiers include higher phosphates and higher fatty acid salts.

[0018] Specifically, the mineral powder has potential activity and becomes hydraulic after reacting with lime, and its activity depends on the mineral powder composition. Cement is selected from at least one of silicate cement, limestone cement, and pozzolanic cement, and its main components are C3S, 2CaO·SiO2 (C2S), 3CaO·Al2O3 (C3A), and 4CaO·Al2O3·Fe2O3 (C4AF). Its function is to increase the clinker mineral phase and become hydraulic. Lime can dissolve the glass in the mineral powder and the mixture (the mixture is composed of mineral powder, lime, and cement), thereby stimulating the activity of the materials (mineral powder and manganese slag), and the calcium carbonate dispersed in the lime can provide crystal nuclei for hydrated calcium silicate (CSH) and calcium hydroxide (CH), so that CSH and CH grow rapidly on the surface of calcium carbonate, accelerate hydration, and improve the density of cement; in addition, calcium carbonate can also form calcium aluminum carbonate with C3A in cement, promoting the intergrowth of crystals and the development of cement strength. The surface modifier is a compound of phosphate and fatty acid salt, which can reduce the friction in the composite system composed of manganese slag and composite activator, improve the fluidity of the composite system, and fully contact each material, thereby ensuring the compressive strength of the product.

[0019] Preferably, in terms of mass percentage, the composite activator includes 35-75% mineral powder, 1-6.5% lime, 18-63% cement, and 1-4.5% surface modifier.

[0020] Further preferably, the composite activator comprises, by mass percentage, 40-70% of mineral powder, 1-6% of lime, 20-58% of cement, and 1-4% of surface modifier.

[0021] Preferably, the surface modifier comprises 35-65% of higher phosphate and 35-65% of higher fatty acid salt by mass percentage.

[0022] Further preferably, the surface modifier comprises 40-60% of higher phosphate and 40-60% of higher fatty acid salt by mass percentage.

[0023] Preferably, the higher phosphate comprises polyphosphate.

[0024] Preferably, the higher fatty acid salt includes at least one of sodium fatty acid, stearic acid, sodium stearate and calcium stearate.

[0025] The second aspect of the present invention provides a method for preparing the composite activator described in the first aspect of the present invention.

[0026] Specifically, the preparation method of the composite activator comprises the following steps:

[0027] Each component is taken to form the composite activator.

[0028] A third aspect of the present invention provides a manganese slag fluidized soil.

[0029] Specifically, the raw materials for preparing the manganese slag fluidized soil include manganese slag, the composite activator described in the first aspect of the present invention and water.

[0030] Preferably, the mass of the composite activator is 4.5-15% of the sum of the mass of the manganese slag and the composite activator; further preferably, the mass of the composite activator is 5-15% of the sum of the mass of the manganese slag and the composite activator.

[0031] Specifically, manganese slag is the main solid waste generated during the electrolytic production of metallic manganese.

[0032] A fourth aspect of the present invention provides a method for preparing manganese slag fluidized soil.

[0033] Specifically, the method for preparing the manganese slag fluidized soil comprises the following steps:

[0034] (1) mixing the manganese slag with the mineral powder, lime and cement to obtain a mixed powder;

[0035] (2) mixing the surface modifier and water to obtain a mixed solution, and mixing the mixed solution with the mixed powder obtained in step (1) to obtain a fluidized soil slurry;

[0036] (3) pouring the fluidized soil slurry obtained in step (2) into a mold and curing it to obtain the manganese slag fluidized soil.

[0037] Preferably, the ratio of the mass of the water to the sum of the mass of the manganese slag, mineral powder, lime, cement and surface modifier is (0.18-0.55):1; further preferably, the ratio of the mass of the water to the sum of the mass of the manganese slag, mineral powder, lime, cement and surface modifier is (0.2-0.5):1.

[0038] The fifth aspect of the present invention provides an application of the composite activator described in the first aspect of the present invention or the manganese slag fluidized soil described in the third aspect in the field of manganese slag resource utilization.

[0039] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0040] (1) The composite activator of the present invention includes mineral powder, lime, cement, and a surface modifier. The mineral powder, cement, lime, and a surfactant are used as the composite activator to activate the activity of manganese slag when treating manganese slag, forming manganese slag fluidized soil with good compressive strength, which can meet the needs of manganese slag fluidized soil road engineering. At the same time, the surface modifier adopts a specific high-grade phosphate and high-grade fatty acid salt compounding method, which can effectively reduce the friction in the composite system, improve the fluidity of the composite system, solve the problem of limited material contact, and improve the compressive strength.

[0041] (2) The manganese slag of the present invention has a relatively high dosage, which accounts for 85-95.5% of the sum of the mass of the manganese slag and the composite activator, which can achieve the purpose of large-scale resource utilization of manganese slag and effectively alleviate environmental pressure. The dosage of the composite activator accounts for 4.5-15% of the sum of the mass of the manganese slag and the composite activator, which has good economic efficiency.

[0042] (3) The method of preparing manganese slag fluidized soil by treating manganese slag with a composite activator is simple and convenient for large-scale application. DETAILED DESCRIPTION

[0043] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be noted that the following embodiments do not limit the protection scope of the present invention.

[0044] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0045] The source information of the relevant raw material components in the application examples and comparative application examples of the present invention is as follows:

[0046] The mineral powder comes from Guangdong Shaoguan Iron and Steel Jiayang New Materials Co., Ltd. It is made by grinding the slag from Shaoguan Iron and Steel's blast furnace. Its main chemical components are silicon dioxide, aluminum oxide, calcium oxide, and iron oxide.

[0047] The lime comes from the roasting kiln of Shaoguan Iron and Steel Co., Ltd., with a purity of 89% and the main impurity being calcium carbonate.

[0048] Manganese slag comes from Guangxi Dameng Manganese Industry Co., Ltd. Its chemical components include SiO2, CaO, SO3 and Al2O3, followed by a small amount of Fe2O3, MgO and MnO. The untreated electrolytic manganese slag has a high natural moisture content, which is 26% in the laboratory, so its moisture content needs to be considered when designing the water-cement ratio.

[0049] Example 1

[0050] A composite activator comprises, by mass percentage, 58% of mineral powder, 35% of cement, 5% of lime and 2% of surface modifier (60% of sodium fatty acid and 40% of polyphosphate by mass).

[0051] A method for preparing a composite stimulant comprises the following steps:

[0052] Mineral powder, lime, cement and surface modifier constitute a composite activator.

[0053] Comparative Example 1

[0054] The only difference between Comparative Example 1 and Example 1 is that the surface modifier in the composite activator of Comparative Example 1 contains only polyphosphate surface modifier, and the mass percentage is 2%. The rest is the same as Example 1.

[0055] Comparative Example 2

[0056] The only difference between Comparative Example 2 and Example 1 is that the surface modifier in the composite activator of Comparative Example 2 is replaced by an equal amount of polyethanol 400 instead of polyphosphate, and the rest is the same as Example 1.

[0057] Comparative Example 3

[0058] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 contains 28% mineral powder and 65% cement, and the rest is the same as Example 1.

[0059] Comparative Example 4

[0060] The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 uses an equal amount of cement to replace lime, that is, 40% cement, and no lime is added. Other aspects are the same as Example 1.

[0061] Application Example 1

[0062] A manganese slag fluidized soil, the preparation raw materials of which include manganese slag, the composite activator of Example 1 and water, and the addition amount of the composite activator is 8% of the total mass of the manganese slag and the composite activator.

[0063] A method for preparing manganese slag fluidized soil comprises the following steps:

[0064] (1) mixing mineral powder, lime and cement to obtain a mixture, and premixing the manganese slag with the mixture in a blender for 2 minutes to obtain a mixed powder;

[0065] (2) mixing the surface modifier and water with a water-to-cement ratio (the ratio of the mass of water to the sum of the mass of the composite activator and the manganese slag) of 0.4, and stirring for 2 minutes to obtain a mixed solution;

[0066] (3) pouring the mixed solution obtained in step (2) into the mixed powder obtained in step (1), mixing for 3 minutes to obtain a fluidized soil slurry, measuring the flow value, and measuring the flow value loss after sampling for 1 hour;

[0067] (4) Pour the fluidized soil slurry obtained in step (3) into a mold, and after 24 hours, collect the surface, and put it into a curing room for curing for 28 days to obtain manganese slag fluidized soil.

[0068] Application Example 2

[0069] A manganese slag fluidized soil, the preparation raw materials of which include manganese slag, the composite activator of Example 1 and water, and the addition amount of the composite activator is 8% of the total mass of the manganese slag and the composite activator.

[0070] A method for preparing manganese slag fluidized soil comprises the following steps:

[0071] (1) mixing mineral powder, lime and cement to obtain a mixture, and premixing the manganese slag with the mixture in a blender for 2 minutes to obtain a mixed powder;

[0072] (2) mixing the surface modifier and water with a water-to-cement ratio (the ratio of the mass of water to the sum of the mass of the composite activator and the manganese slag) of 0.3, and stirring for 2 minutes to obtain a mixed solution;

[0073] (3) pouring the mixed solution obtained in step (2) into the mixed powder obtained in step (1), mixing for 3 minutes to obtain a fluidized soil slurry, measuring the flow value, and measuring the flow value loss after sampling for 1 hour;

[0074] (4) Pour the fluidized soil slurry obtained in step (3) into a mold, and after 24 hours, collect the surface, and put it into a curing room for curing for 28 days to obtain manganese slag fluidized soil.

[0075] Application Example 3

[0076] A manganese slag fluidized soil, the preparation raw materials of which include manganese slag and the composite activator of Example 1, and the addition amount of the composite activator is 6% of the total mass of the manganese slag and the composite activator.

[0077] A method for preparing manganese slag fluidized soil comprises the following steps:

[0078] (1) mixing mineral powder, lime and cement to obtain a mixture, and premixing the manganese slag with the mixture in a blender for 2 minutes to obtain a mixed powder;

[0079] (2) mixing the surface modifier and water with a water-to-cement ratio (the ratio of the mass of water to the sum of the mass of the composite activator and the manganese slag) of 0.4, and stirring for 2 minutes to obtain a mixed solution;

[0080] (3) pouring the mixed solution obtained in step (2) into the mixed powder obtained in step (1), mixing for 3 minutes to obtain a fluidized soil slurry, measuring the flow value, and measuring the flow value loss after sampling for 1 hour;

[0081] (4) Pour the fluidized soil slurry obtained in step (3) into a mold, and after 24 hours, collect the surface, and put it into a curing room for curing for 28 days to obtain manganese slag fluidized soil.

[0082] Comparative application example 1

[0083] The difference between Comparative Application Example 1 and Application Example 1 is that the composite exciter in Comparative Application Example 1 is the composite exciter in Comparative Example 1, and the rest is the same as Application Example 1.

[0084] Comparative Application Example 2

[0085] The only difference between Comparative Application Example 2 and Application Example 1 is that the composite exciter in Comparative Application Example 2 is the composite exciter of Comparative Example 2, and the rest is the same as Application Example 1.

[0086] Comparative Application Example 3

[0087] The only difference between Comparative Application Example 3 and Application Example 1 is that the composite exciter in Comparative Application Example 3 is the composite exciter of Comparative Example 3, and the rest is the same as Application Example 1.

[0088] Comparative Application Example 4

[0089] The only difference between Comparative Application Example 4 and Application Example 1 is that the composite exciter in Comparative Application Example 4 is the composite exciter of Comparative Example 4, and the rest is the same as Application Example 1.

[0090] Comparative Application Example 5

[0091] The only difference between Comparative Application Example 5 and Application Example 1 is that the amount of the composite activator in the raw material for preparing the manganese slag fluidized soil in Comparative Application Example 5 is 2% of the total mass of the manganese slag and the composite activator, and the rest is the same as Application Example 1.

[0092] Comparative Application Example 6

[0093] The only difference between Comparative Application Example 6 and Application Example 1 is that the amount of the composite activator in the raw material for preparing the manganese slag fluidized soil in Comparative Application Example 6 is 16% of the total mass of the manganese slag and the composite activator, and the rest is the same as Application Example 1.

[0094] Performance Testing

[0095] The fluidity and 1-hour fluidity loss tests were performed on the fluidized soil slurries prepared in Example 1-3 and Comparative Application Examples 1-6, respectively, and the test methods were carried out in accordance with GB / T 50448-2015.

[0096] The manganese slag fluidized soil prepared in Example 1-3 and Comparative Application Example 1-6 were respectively subjected to a 28-day (28d) compressive strength test, and the test method was carried out in accordance with JTG 3430-2020.

[0097] The performance test results of the fluidized soil slurry and manganese slag fluidized soil prepared in Application Examples 1-3 and Comparative Application Examples 1-6 are shown in Table 1.

[0098] Table 1: Performance test results of fluidized soil slurry and manganese slag fluidized soil prepared in Application Examples 1-3 and Comparative Application Examples 1-6

[0099] Group Fluidity / mm 1 hour fluidity / mm 28d compressive strength / MPa Application Example 1 200 200 2 Application Example 2 170 170 1.8 Application Example 3 200 200 1.7 Comparative application example 1 150 145 0.9 Comparative Application Example 2 155 140 0.85 Comparative Application Example 3 200 100 1.5 Comparative Application Example 4 200 200 1.2 Comparative Application Example 5 200 200 0.4 Comparative Application Example 6 200 185 3.2

[0100] As can be seen from Table 1, the fluidized soil slurry prepared by the present invention has suitable fluidity and fluidity loss, which is convenient for construction; the prepared manganese slag fluidized soil has good 28d compressive strength, which can meet the needs of manganese slag fluidized soil road engineering. In addition, when preparing manganese slag fluidized soil, the present invention uses a small amount of composite activator, and manganese slag has a higher dosage, and the dosage in the mixed powder reaches 85-95.5%, which can achieve the purpose of large-scale resource utilization of manganese slag, alleviate environmental pressure, and has good economic efficiency.

[0101] From Application Example 2 and Application Example 1, it can be seen that Application Example 2 reduces the water-cement ratio, resulting in a decrease in the dispersion of the phases, insufficient water required for partial hydration, and insufficient space to accommodate the hydration products, which delays the late hydration reaction, resulting in a decrease in the 28d compressive strength and flow value. From Application Example 3 and Application Example 1, it can be seen that Application Example 3 has a lower 28d strength than Application Example 1 due to the decrease in the amount of composite activator added.

[0102] Compared with Application Example 1, the surface modifier in the composite activator of Comparative Application Example 1 contains only polyphosphate, which makes the fluidity between particles worse, the material contact is limited, and the strength is reduced. Compared with Application Example 1, the surface modifier in the composite activator of Comparative Application Example 2 is polyethanol 400, which reduces the fluidity and 28d compressive strength. Comparative Application Examples 1 and 2 illustrate that the use of a specific polyphosphate and sodium fatty acid compounded surface modifier plays an important role in improving the fluidity and 28d compressive strength of manganese slag fluid soil.

[0103] Compared with Application Example 1, Application Example 3 significantly increased the cement content and reduced the mineral powder output, resulting in excessive fluidity loss, pipe blockage and inability to construct. The early coagulation was too fast, resulting in cracking, and the later strength growth was slow. Compared with Application Example 1, Application Example 4 did not add lime, resulting in reduced mineral powder excitation efficiency and reduced strength.

[0104] Compared with Application Example 1, Application Example 5 has a lower amount of composite excitation dosage, which leads to a significant decrease in 28d compressive strength and cannot meet the construction requirements. Compared with Application Example 1, Application Example 6 has a larger amount of composite excitation dosage. Although the 28d compressive strength increases, the economic efficiency becomes worse, and the hydration is too fast, resulting in increased fluidity loss.

[0105] In summary, the present invention uses mineral powder, cement, lime and surfactant as composite activators to activate the activity of manganese slag when treating manganese slag, forming manganese slag fluid soil with good compressive strength, and the manganese slag has a high dosage, accounting for 85-95.5% of the total mass of the mixed powder, which can achieve the purpose of large-scale resource utilization of manganese slag, alleviate environmental pressure, and has good economy. At the same time, the surface modifier adopts a specific high-grade phosphate and high-grade fatty acid salt compounding method, which can effectively reduce the friction in the composite system, improve the fluidity of the composite system, solve the problem of limited material contact, and improve the compressive strength.

[0106] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A composite activator, characterized in that: Including mineral powder, lime, cement, surface modifier; The surface modifiers include higher phosphates and higher fatty acid salts.

2. The composite activator according to claim 1, characterized in that: Calculated by mass percentage, the composite activator includes 35-75% of mineral powder, 1-6.5% of lime, 18-63% of cement and 1-4.5% of surface modifier.

3. The composite activator according to claim 2, characterized in that: Calculated by mass percentage, the surface modifier comprises 35-65% of higher phosphate and 35-65% of higher fatty acid salt.

4. The composite activator according to claim 3, characterized in that: The higher phosphate includes polyphosphate; and / or the higher fatty acid salt includes at least one of sodium fatty acid, stearic acid, sodium stearate, and calcium stearate.

5. The method for preparing the composite activator according to any one of claims 1 to 4, characterized in that: The following steps are involved: Each component is taken to form the composite activator.

6. A manganese slag fluidized soil, characterized in that: The raw materials for preparing the catalyst include manganese slag, the composite activator described in any one of claims 1 to 4 and water.

7. The manganese slag fluidized soil according to claim 6, characterized in that: The mass of the composite activator is 4.5-15% of the sum of the mass of the manganese slag and the composite activator.

8. The method for preparing manganese slag fluidized soil according to any one of claims 6 to 7, characterized in that: The following steps are involved: (1) mixing the manganese slag with the mineral powder, lime and cement to obtain a mixed powder; (2) mixing the surface modifier and water to obtain a mixed solution, and mixing the mixed solution with the mixed powder obtained in step (1) to obtain a fluidized soil slurry; (3) pouring the fluidized soil slurry obtained in step (2) into a mold and curing it to obtain the manganese slag fluidized soil.

9. The preparation method according to claim 8, characterized in that: The ratio of the mass of the water to the sum of the mass of the manganese slag, mineral powder, lime, cement and surface modifier is (0.18-0.55):

1.

10. Use of the composite activator described in any one of claims 1 to 4 or the manganese slag fluidized soil described in any one of claims 6 to 7 in the field of manganese slag resource utilization.