CN114349380B - Preparation method of dry-process fine-tailings machine-made sand and high-strength concrete containing machine-made sand - Google Patents
Preparation method of dry-process fine-tailings machine-made sand and high-strength concrete containing machine-made sand Download PDFInfo
- Publication number
- CN114349380B CN114349380B CN202111632952.1A CN202111632952A CN114349380B CN 114349380 B CN114349380 B CN 114349380B CN 202111632952 A CN202111632952 A CN 202111632952A CN 114349380 B CN114349380 B CN 114349380B
- Authority
- CN
- China
- Prior art keywords
- machine
- sand
- made sand
- parts
- mass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The application relates to a preparation method of dry-process fine tailing machine-made sand and high-strength concrete containing the machine-made sand, wherein the treatment method comprises the following specific steps: step 1, limestone tailings pretreatment: step 2, crushing the pretreated limestone tailings to prepare sand to obtain fine sand with the average grain diameter of 0.25-0.05 mm; step 3, vibrating and screening the fine sand; step 4, recovering and filtering the screened fine sand; step 5, carrying out primary dust removal treatment and secondary dust removal treatment on the fine sand left after recovery and filtration to obtain rough machine manufactured sand; step 6, collecting the stone powder obtained by dust removal; blanking the rough manufactured machine-made sand; and 7, soaking the crude machine-made sand in a mixed solution of methyl acetate, tartaric acid and ethanol, uniformly stirring, standing for 6 hours, and drying to obtain dry-process refined tailing machine-made sand. This application has the effect that promotes the finished product quality of lime stone tailing machine system sand.
Description
Technical Field
The application relates to the technical field of machine-made sand treatment, in particular to a preparation method of dry-method fine tailing machine-made sand and high-strength concrete containing the machine-made sand.
Background
The tailings are solid wastes discharged by ore dressing plants after crushing and grinding ores and selecting 'useful components' under specific technical conditions, are large solid wastes with the largest output and the lowest comprehensive utilization rate in China at present, and how to reasonably and comprehensively utilize the tailings becomes one of the problems which are highly regarded in China and even in the world.
The natural sand is a non-renewable local resource, so that the natural sand resource is greatly reduced and nearly exhausted at present, the contradiction between supply and demand of the sand for concrete is particularly prominent, in recent years, the use of the machine-made sand in concrete is gradually increased, the proportion of the machine-made sand to the total amount of the sandstone is also increased year by year, and the preparation of the tailings into the machine-made sand which can be used for the concrete is a technological improvement for recycling the tailings and changing waste into valuable.
Limestone resources are rich and mining cost is low, limestone tailings are commonly used for preparing machine-made sand, but the limestone tailings are loose in structure and are not uniformly cracked in the crushing and impacting process, so that the prepared machine-made sand finished product is poor in particle shape, too much stone powder is on the surface, the performance of the machine-made sand is poor, and the binding property of the machine-made sand added into concrete or mortar and a supporting effect of the machine-made sand as an aggregate are influenced. In response to this technical problem, the inventor believes that the existing limestone tailing manufactured sand preparation method has a large lifting space.
Disclosure of Invention
In order to improve the quality of finished products of the limestone tailing ore-made sand and enable the machine-made sand made from the tailings to meet the performance requirements of high-strength concrete, the application provides a dry-method fine tailing ore-made sand preparation method and the high-strength concrete containing the machine-made sand.
In a first aspect, the method for preparing machine-made sand from fine tailings by a dry method adopts the following technical scheme: a preparation method of dry-process fine tailing machine-made sand comprises the following specific steps:
step 1, limestone tailing pretreatment:
step 1-1, collecting 500-520 parts by mass of limestone tailings, adding 80-100 parts by mass of polyacrylic acid solution into the limestone tailings, adding 20-30 parts by mass of vinyl sulfonic acid, 15-20 parts by mass of polyacrylamide hydrochloride and 30-35 parts by mass of calcium chloride aqueous solution in the mixing and stirring process, stirring at the temperature of 30-35 ℃ for 1-2h, then preserving heat, standing for 24h, washing with deionized water, and drying in vacuum to obtain primary modified limestone tailings;
step 1-2, mixing 15-17 parts by mass of kudzu root starch and 13-16 parts by mass of xanthan gum, gelatinizing the mixture in a water bath at 90-110 ℃, cooling the gelatinized mixture, adding 7-9.5 parts by mass of N, N-methylene bisacrylamide and 7-9.5 parts by mass of sodium persulfate, and stirring the mixture for 2-3 hours to obtain a coating solution;
step 1-3, adding the coating solution into the primary modified limestone tailings, uniformly stirring, standing, cooling, and uniformly stirring again to obtain secondary modified limestone tailings;
step 2, crushing the secondary modified limestone tailings to prepare sand to obtain fine sand with the average grain size of 0.25-0.05 mm;
step 3, vibrating and screening the fine sand;
step 4, recovering and filtering the screened fine sand;
step 5, performing primary dust removal treatment and secondary dust removal treatment on the fine sand left after recovery and filtration to obtain coarse machine-made sand;
step 6, collecting the stone powder obtained by dust removal; blanking the rough manufactured machine-made sand;
and 7, soaking the crude machine-made sand in a mixed solution of 17-22 parts by mass of methyl acetate, 12-16 parts by mass of tartaric acid and 20-30 parts by mass of ethanol, uniformly stirring, standing for 6 hours, carrying out solid-liquid separation, discharging upper-layer liquid, washing settled sand with clear water, and drying the settled sand to obtain dry-process fine tailing machine-made sand.
By adopting the technical scheme, the limestone tailings are modified for the first time, and under the assistance of the polyacrylic acid solution as a stabilizer, the vinylsulfonic acid, the polyacrylamide hydrochloride and the calcium chloride aqueous solution act together, so that the amorphous crystallization recrystallization in the limestone is promoted, the crystallization degree in the limestone is improved, and the strength of the limestone is improved; then adding the limestone tailings with improved strength into a coating liquid, mixing and pasting kudzu root starch and xanthan gum in the coating liquid, adding N, N-methylene bisacrylamide and sodium persulfate, and mutually fusing the kudzu root starch and the xanthan gum on the surface of the limestone subjected to primary modification to form a layer of elastic protective film under the synergistic action of the N, N-methylene bisacrylamide and the sodium persulfate, wherein when the limestone is subjected to subsequent crushing, the elastic protective film not only contributes to reducing the stone powder generated by mutual collision among stones in the crushing process, but also contributes to shaping in the crushing process of the limestone; and finally, eliminating the residual elastic protective film on the surface of the limestone by using a mixed solution of methyl acetate, tartaric acid and ethanol, wherein the groups in the elastic protective film react with the groups in the mixed solution, so that the elastic coating film is gradually dissolved in the mixed solution, the protective film on the outer layer of the limestone is removed, and the influence of the protective film on the surface activity of the limestone is reduced. Through the layer-by-layer modification treatment on the inside and the outside of the limestone, the obtained dry-method fine tailing machine manufactured sand has higher strength, the stone powder content of the dry-method fine tailing machine manufactured sand is controllable, and the dry-method fine tailing machine manufactured sand is more suitable to be used as a raw material to be applied to high-strength concrete.
Preferably, 0.5 to 0.7 parts by mass of polyvinyl alcohol is also added in the step 1 to 2.
By adopting the technical scheme, the polyvinyl alcohol is added into the coating liquid, so that the elasticity of the coating liquid for forming a film on the surface of limestone is promoted, the decomposability of the film formed by the coating liquid is promoted, the subsequent film elimination is more sufficient and thorough, and the subsequent effect obtained after the machine-made sand is treated is improved more obviously.
Preferably, 0.3-0.5 part by mass of n-butanol or acetamide is also added in the step 7.
By adopting the technical scheme, the n-butyl alcohol and the acetamide can be added into the mixed solution independently or together to play a certain role in helping dissolution, so that the elimination of the elastic protective film is further promoted, and the film elimination is more sufficient.
Preferably, the step 7 further includes a process of performing post-treatment on the fine dry tailing manufactured sand, and specifically includes the following steps: adding 30-35 parts by mass of toluene, 7-10 parts by mass of coupling agent, 10-15 parts by mass of polyaspartic acid and 12-15 parts by mass of L-3, 4-dihydroxyphenylalanine into finished product machine-made sand, uniformly mixing, reacting at the temperature of 100-.
Through adopting above-mentioned technical scheme, certain infiltration complex has been formed in the synergism between polyaspartic acid, L-3, 4-dihydroxyphenylalanine and the toluene three, this complex permeates into the inside interlaminar structure of lime stone for the inside closely lapped lamellar structure of the brick type that forms of lime stone, and then has played the effect of filling the reinforcement to the lime stone, and then has further promoted the compressive strength of mechanism sand, and make mechanism sand play better aggregate effect in adding the concrete under the influence of coupling agent, it is better to combine with the sizing material.
Preferably, the coupling agent is vinyltrimethoxysilane or vinyltris (beta-methoxyethoxy) silane.
By adopting the technical scheme, the vinyltrimethoxysilane and the vinyltris (beta-methoxyethoxy) silane can be well dissolved in the toluene, so that the dispersity and the compatibility among all components in the system are enhanced, and the filling and reinforcing effects on the machine-made sand are further improved.
Preferably, 0.2 to 0.5 mass part of hydroquinone is also added in the post-treatment process of the finished machine-made sand in the step 7.
By adopting the technical scheme, hydroquinone is added into the mixed solution to play a certain role in inhibiting polymerization, mutual agglomeration among machine-made sand is reduced, the dispersibility among machine-made sand particles is good, and the infiltration degree of an infiltration complex formed by synergistic action among polyaspartic acid, methylbenzene and L-3, 4-dihydroxyphenylalanine to the machine-made sand is favorably enhanced, so that the filling and reinforcing effects on the machine-made sand are improved.
In a second aspect, the present application provides a dry process fine tailings mining sand, which adopts the following technical scheme:
the dry-process refined tailing machine-made sand is prepared by the preparation method of the dry-process refined tailing machine-made sand.
The machine-made sand prepared by the preparation method has better strength, less surface floating powder content and better surface activity, and can improve the strength performance of concrete or mortar when being added into the concrete or mortar.
In a second aspect, the present application provides a high-strength concrete, which adopts the following technical scheme:
the high-strength concrete is prepared from a concrete mixture, wherein the concrete mixture comprises the following raw materials in parts by mass: 401 parts of cement 381-5, 657 parts of machine-made sand 637-1060 parts, 1060 parts of broken stone 1040-175 parts of water 155-100 parts of mineral powder, 82-100 parts of fly ash and 12.5-15.5 parts of polycarboxylic acid high-performance water reducing agent; the machine-made sand is the dry-process fine tailing machine-made sand prepared by the preparation method.
The tailing machine-made sand obtained by dry fine processing is added into the concrete raw material, and the tailing machine-made sand has better strength and less stone powder content, so that the binding property between the machine-made sand and other components in the concrete raw material is better, the aggregate action of the machine-made sand is more prominent, and the strength performance of the concrete is prominent.
In summary, the present application includes at least one of the following beneficial technical effects:
1. in the application, the limestone tailings are firstly modified for one time, and the internal crystallization degree of the limestone after the one-time modification is improved, so that the strength of the limestone is improved; then adding the limestone tailings subjected to primary modification into a coating liquid, wherein the kudzu root starch, xanthan gum, N-methylene bisacrylamide and sodium persulfate in the coating liquid are subjected to synergistic action, and the surface of the limestone subjected to primary modification is mutually blended to form a layer of elastic protective film; and finally, eliminating the film of the elastic protective film remained on the surface of the limestone by using a mixed solution of methyl acetate, tartaric acid and ethanol, thereby eliminating the influence of the protective film on the surface activity of the machine-made sand. The interior and the exterior of the limestone are modified layer by layer, so that the obtained limestone tailing machine-made sand has higher strength, the stone powder content of the machine-made sand is better controlled, and the adaptability of the machine-made sand and concrete is improved;
2. according to the method, the post-treatment is carried out on the machine-made sand after the membrane is eliminated, a certain permeable complex is formed by the synergistic effect of the polyaspartic acid, the toluene and the L-3, 4-dihydroxy phenylalanine in the post-treatment process, and the complex permeates into the limestone, so that a brick-type tightly-lapped layered structure is formed in the limestone, the limestone is filled and reinforced, and the compressive strength of the machine-made sand is further improved;
3. carry out coarse crushing, moderate breakage and thin breakage to the limestone tailing in proper order in this application, triple breakage for the moulding effect of particle shape is better in the limestone tailing crushing process, and helps obtaining the better mechanism sand of gradation.
Detailed Description
The present application will be described in further detail with reference to examples.
The source information of the raw materials used in the following examples and comparative examples is detailed in table 1.
TABLE 1
Examples
Example 1
The embodiment discloses a preparation method of dry-process fine tailing machine-made sand, which specifically comprises the following steps:
step 1, limestone tailings pretreatment:
step 1-1, collecting 500kg of limestone tailings, adding 80kg of polyacrylic acid solution into the limestone tailings for mixing, adding 20kg of vinyl sulfonic acid, 15kg of polyacrylamide hydrochloride and 30kg of calcium chloride aqueous solution in the stirring process at a stirring speed of 40r/min, stirring for 2 hours at a temperature of 30 ℃ and a rotating speed of 60r/min, then keeping the temperature and standing for 24 hours, washing with deionized water, and drying at constant temperature for 1 hour at 80 ℃ by using a vacuum drier to obtain primary modified limestone tailings;
step 1-2, mixing 15kg of kudzu root starch and 13kg of xanthan gum, adding the mixture into a water bath kettle, gelatinizing the mixture in a water bath at 90 ℃, stopping heating after the gelatinized mixture is viscous, pouring the gelatinized mixture into a stirring pool, adding 7kgN, N-methylene bisacrylamide and 7kg of sodium persulfate, and stirring the mixture for 2 hours at the speed of 70r/min to prepare a coating solution;
step 1-3, adding the coating solution into the primary modified limestone tailings, stirring for 2 hours at the speed of 50r/min, standing and cooling to room temperature, and stirring for 5 minutes at the speed of 60r/min by using a stirrer to obtain secondary modified limestone tailings;
step 2, feeding the secondary modified limestone tailings into a raw material feeding bin, feeding the secondary modified limestone tailings into a USF394H sand making machine through an aggregate belt conveyor at one time, and crushing the limestone tailings to make sand so as to obtain fine sand with the particle size of 0.25-0.05 mm;
step 3, adding the spun yarn into a ZS2468 vibrating screen, and carrying out vibrating screening on the vibrating screen with the amplitude of 6mm, the length, the width and the height of 8094, the length, the width and the height of 3804 (mm):
step 4, feeding the fine sand with the particle size of 0.25-0.05mm obtained by screening into a PD650 recovery filter, and recovering and filtering the fine sand with the particle size;
step 5, sending the fine sand left after recovery and filtration into an NMC series pulse dust collector, and carrying out primary dust removal treatment under the conditions that the working pressure is 0.5MPa, the ambient temperature is 30 ℃ and the pulse interval time is 30 s; then sending the mixture into a 2LQM660 offline pulse dust collector, and carrying out secondary dust collection treatment under the conditions that the working pressure is 0.7MPa, the pulse interval time is 30s and the ambient temperature is 30 ℃ to obtain rough-machine manufactured sand;
step 6, conveying the stone powder collected by dust removal and filtration to an FG100 type powder tank through a stone powder conveying and lifting system for storage; conveying the coarse machine-made sand to a feed opening for feeding;
and 7, soaking the crude machine-made sand obtained by blanking in a mixed solution of 17kg of methyl acetate, 1kg of tartaric acid and 20kg of ethanol, stirring for 30min at the temperature of 35 ℃ and at the rotating speed of 100r/min, standing at constant temperature for 6h, settling the machine-made sand at the bottom, pumping and discharging the upper liquid by using a water pump, adding clear water into an elutriation machine for elutriation, putting the machine-made sand subjected to elutriation twice into a drying chamber, and drying at the room temperature of 60 ℃ for 24h to obtain the dry fine tailing machine-made sand with the particle size meeting the secondary standard.
Example 2
A preparation method of dry-process fine tailing machine-made sand is different from that of the embodiment 1 in that: the content and the process parameters of each component in the treatment process are different, and the method comprises the following specific steps:
in the step 1-1, 520kg of limestone tailings are collected, 100kg of polyacrylic acid solution is added into the limestone tailings to be mixed, 30kg of vinyl sulfonic acid, 20kg of polyacrylamide hydrochloride and 35kg of calcium chloride aqueous solution are added in the stirring process, and the mixture is stirred for 1 hour at the temperature of 35 ℃;
step 1-2, mixing 17kg of kudzuvine root starch and 16kg of xanthan gum, adding the mixture into a water bath kettle, carrying out water bath gelatinization at 110 ℃, cooling, adding 9.5kg of N, N-methylene bisacrylamide and 9.5kg of sodium persulfate, and stirring for 3 hours;
step 7, soaking the crude machine-made sand in a mixed solution of 22kg of methyl acetate, 16kg of tartaric acid and 30kg of ethanol.
Example 3
A preparation method of dry-process fine tailing machine-made sand is different from the embodiment 2 in that: the step 7 also comprises a process for post-processing the dry fine tailing manufactured sand, and the process specifically comprises the following steps: 30kg of toluene, 7kg of vinyl trimethoxy silane, 10kg of polyaspartic acid and 12kgL-3, 4-dihydroxy phenylalanine are added into the finished product machine-made sand, the mixture reacts for 10 hours at the temperature of 100 ℃, solid-liquid separation is carried out after standing and precipitation, the upper layer liquid is discharged, the obtained machine-made sand solid product is subjected to ultrasonic cleaning by deionized water at the ultrasonic frequency of 37kHz, and the mixture is dried for 1 hour at the constant temperature of 60 ℃ by a vacuum drier, so that the post-processed dry-process fine-tailings machine-made sand is obtained.
Example 4
A preparation method of dry-process fine tailing machine-made sand is different from that of the embodiment 3 in that: the content and technological parameters of each component in the post-treatment process are different, and the coupling agent is selected differently, which specifically comprises the following steps: adding 35kg of toluene, 10kg of vinyl tri (beta-methoxyethoxy) silane, 15kg of polyaspartic acid and 15kgL-3, 4-dihydroxyphenylalanine into the finished machine-made sand, and reacting for 8 hours at 110 ℃.
Examples 5 to 6
A preparation method of dry-process fine tailing machine-made sand is different from the embodiment 3 in that: in the post-treatment process of the step 7, 0.2kg of hydroquinone and 0.5kg of hydroquinone are respectively added.
Examples 7 to 8
A preparation method of dry-process fine tailing machine-made sand is different from the embodiment 2 in that: 0.5kg and 0.7kg of polyvinyl alcohol are also added in the step 1-2 respectively.
Example 9
A preparation method of dry-process fine tailing machine-made sand is different from that of the embodiment 2 in that: 0.3kg of n-butanol was also added in step 7.
Example 10
A preparation method of dry-process fine tailing machine-made sand is different from the embodiment 2 in that: 0.5kg of acetamide was also added in step 7.
Example 11
A preparation method of dry-process fine tailing machine-made sand is different from the embodiment 2 in that: 0.5kg of polyvinyl alcohol is also added in the step 1-2; 0.5kg of acetamide is also added in the step 7; the step 7 also comprises a process for post-treating the finished machine-made sand, and the process specifically comprises the following steps: 30kg of toluene, 7kg of vinyltrimethoxysilane, 10kg of polyaspartic acid, 12kgL-3, 4-dihydroxyphenylalanine and 0.5kg of hydroquinone are added into the finished product machine-made sand, the mixture reacts for 10 hours at 100 ℃, solid-liquid separation is realized after standing and precipitation, the upper liquid is discharged, the obtained machine-made sand solid product is subjected to ultrasonic cleaning by deionized water at the ultrasonic frequency of 37kHz, and drying is carried out by a vacuum dryer, so that the post-processed dry fine tailing machine-made sand is obtained.
Comparative example
Comparative example 1
The difference between the preparation method of the dry-process refined tailing machine-made sand and the embodiment 2 is that the limestone tailings are not modified for one time.
Comparative example 2
The difference between the preparation method of the dry-process fine tailing machine-made sand and the embodiment 2 is that the limestone tailings are not subjected to secondary modification.
Comparative example 3
This comparative example purchased a commercially available natural sand, and was subjected to performance testing.
Application example
Application example 1
This application example discloses a high-strength concrete, it is prepared by the concrete mix, specifically includes in the concrete mix: 381kg of P.II 42.5R cement, 637kg of machine-made sand, 1040kg of 15-20mm broken stone, 155kg of water, 82kg of S95 mineral powder and 82kg of dipolar fly ash; 12.5kg of SJ-ZSC100 polycarboxylic acid high-performance water reducing agent. The machine-made sand in the application example is the dry-process fine tailing machine-made sand prepared in the embodiment 2.
The application example also discloses a preparation method of the high-strength concrete, which specifically comprises the following steps:
step 1, mixing P & II 42.5R cement, machine-made sand, crushed stone of 15-20mm, water, S95 mineral powder, dipolar fly ash and SJ-ZSC100 polycarboxylic acid high-performance water reducing agent, adding into a stirrer, and stirring for 1h at the rotating speed of 40R/min to obtain a concrete mixture;
and 2, standing the concrete mixture for a day and a night at the temperature of 23 ℃, and putting the mixture into a standard curing room with the temperature of 20 ℃ and the relative humidity of 95% for curing for 28 days to obtain the high-strength concrete.
Application example 2
The application example discloses high-strength concrete, which is different from the application example 1 in that the content of each raw material component is different, and the machine-made sand is prepared by using a dry-method fine tailing machine prepared in the embodiment 11, and specifically comprises the following steps: 401kgP & II 42.5R cement, 657kg machine-made sand, 1060kg15-20mm crushed stone, 175kg water, 100kgS95 mineral powder, 100kg dipolar fly ash and 15.5kg SJ-ZSC100 polycarboxylic acid high-performance water reducing agent are mixed and added into a stirrer.
Application example 3
The application example discloses a high-strength concrete, which is different from the application example 1 in that: the machine-made sand is the dry-process fine tailing machine-made sand prepared in the comparative example 1.
Performance test
1. According to the regulation of the national standard GB/T14684-2011 construction sand: respectively carrying out performance detection on apparent density, stone powder content and crushing index value on examples 1-11 and comparative examples 1-3 of the application, carrying out particle grading detection on example 1, and detailed performance detection data are shown in tables 2-3;
the apparent density of the machine-made sand represents the mass of a unit microscopic appearance volume (including internal closed pores) of the material, the larger the apparent density is, the fewer the internal gaps of the machine-made sand are, the more compact the interior is, and the better the strength performance of the machine-made sand is;
the content of the stone powder refers to the content of particles with the particle size of less than 75 microns in the machine-made sand, in the high-strength concrete, the water-cement ratio is small, and the content of the stone powder has an important influence on the workability of the concrete, so that the stone powder in the machine-made sand needs to be strictly limited, the content of the stone powder is reduced, and the influence of the content of the stone powder on the hydration process of the high-strength concrete is favorably reduced;
the mud block content refers to the particle content of sand with the original particle size of more than 1.18mm and less than 600 mu m after water washing and hand pinching, if the mud block content of machine-made sand is too large, the influence on the quality of concrete is great, the mud block content is large, the water consumption of concrete is increased, the plasticity retention performance is deteriorated, the shrinkage is increased, and the concrete strength is inevitably reduced;
the crushing index value is the capability of resisting damage of the machine-made sand under the action of external force, is an important index for indirectly expressing the firmness of the machine-made sand, directly influences the strength of the prepared concrete, and particularly has the greatest influence on high-strength concrete, the lower the crushing index value is, the less the damage loss of the machine-made sand is, and the better the strength performance of the machine-made sand is.
2. According to the method for testing the compressive strength in GB/T50081-2016 standard of test method for mechanical properties of common concrete, 3d and 28d compressive strength tests are carried out on the samples 1-3, and the test results are detailed in Table 4.
TABLE 2 Performance test of apparent Density, Stone powder content, Clay content and crush index values for examples 1-11 and comparative examples 1-3
TABLE 3 particle grading test of example 1
TABLE 4 compressive Strength testing of application examples 1-3 at 3d, 28d
| 3d compressive strength | 28d compressive strength | |
| Application example 1 | 47.0 | 76.6 |
| Application example 2 | 49.0 | 78.8 |
| Application example 3 | 45.9 | 61.3 |
According to the performance detection data in tables 2 and 3, in examples 1 and 2, the limestone tailings are modified for the first time by mixing polyacrylic acid solution, vinyl sulfonic acid, polyacrylamide hydrochloride and calcium chloride aqueous solution; and preparing a coating solution from kudzuvine root starch, xanthan gum, N-methylene bisacrylamide and sodium persulfate, performing secondary modification on the limestone tailings subjected to primary modification, and finally performing membrane removal treatment through a mixed solution of methyl acetate, tartaric acid and ethanol in a sand making process, so that the values of the apparent density, the stone powder content, the clod content and the crushing index value of the machine-made sand prepared in the embodiments 1 and 2 all reach the standard requirement of the grade II machine-made sand, and the particle grading of the machine-made sand prepared in the embodiment 1 also meets the standard requirement of the grade II machine-made sand.
According to the analysis of the performance detection data of the comparative examples 1-3, the limestone tailings are not modified for the first time in the comparative example 1, and the apparent density of the machine-made sand prepared in the comparative example 1 is obviously reduced compared with that of the machine-made sand prepared in the example 2; the content of the stone powder, the content of the mud blocks and the crushing index value are all obviously increased, which shows that the strength performance of the machine-made sand prepared in the comparative example 1 is weaker; in the comparative example 2, the limestone tailings are not subjected to secondary modification, the apparent density of the machine-made sand prepared in the comparative example 2 is reduced, the stone powder content, the mud block content and the crushing index value are obviously increased, and the sand grain shape has edges and corners and is not round, compared with the machine-made sand prepared in the example 2, and the machine-made sand prepared in the comparative example 2 is lower in strength performance and poorer in grain shape. In comparative example 3, the performance of the commercial natural sand is tested, and the performance test data of the machine-made sand prepared in example 2 is superior to that of the natural sand in comparative example 3, so that the machine-made sand prepared by the preparation method of the dry-process fine tailing machine-made sand in the application is further proved to have better performance and can be completely used instead of the natural sand.
The inventor analyzes that amorphous crystals exist in the limestone, and the amorphous crystals are converted or recrystallized according to a specific direction under the combined action of vinyl sulfonic acid, polyacrylamide hydrochloride and a calcium chloride aqueous solution under the assistance of a polyacrylic acid solution as a stabilizer, so that the internal crystallinity of the limestone is improved, the ordered degree of the crystals is improved, and the strength performance of the limestone particles is improved by visual reflection; the strength performance is improved, and the problem that a large amount of stone powder is generated due to poor strength is reduced; then mixing and pasting the kudzu root starch and the xanthan gum in the coating liquid, and matching with N, N-methylene bisacrylamide and sodium persulfate, wherein the four materials are subjected to synergistic action to mutually fuse the surface of the limestone subjected to primary modification to form an elastic protective film, so that the limestone powder generated by friction between particle bodies is reduced when the limestone is crushed and collided under the protection of the elastic protective film, and the particle shaping is better realized under the elastic action of the protective film; and finally, eliminating the film of the residual elastic protective film on the surface of the limestone by using a mixed solution of methyl acetate, tartaric acid and ethanol, thereby ensuring the surface activity of the machine-made sand. However, only the limestone tailings are modified once or twice, and the synergistic effect of the limestone tailings in the two-time modification process is lacked, so that the prepared machine-made sand cannot reach the performance index of the machine-made sand prepared in the embodiment 2.
Examples 3 and 4 post-treat the machine-made sand based on example 2, and the apparent density of the machine-made sand prepared in examples 3 and 4 is improved and the crushing index value is reduced compared with the machine-made sand prepared in example 2, which indicates that the strength performance of the machine-made sand prepared in examples 3 and 4 is improved, and the inventor analyzes that a certain permeable complex is possibly formed by the synergistic action among polyaspartic acid, L-3, 4-dihydroxyphenylalanine and toluene in the post-treatment process, the complex can permeate into the limestone, and a brick type tightly lapped structure is formed inside the limestone by filling and bonding in the gaps of lamellar crystals inside the limestone, so that the internal structure of the limestone is compact, the strength of the limestone is improved, and the improvement of the limestone strength also helps to reduce the generation of limestone powder in the crushing collision process of the limestone, and a coupling agent is connected in the post-treatment, so that the surface activity of the machine-made sand is enhanced by the coupling agent, and the effect of the machine-made sand in concrete is facilitated.
Examples 5 and 6, in which hydroquinone was added to example 4, the apparent density of the machine-made sands obtained in examples 5 and 6 was increased and the crush index value was slightly decreased compared to the machine-made sands obtained in example 4, which indicates that the strength properties of the machine-made sands obtained in examples 5 and 6 were further improved; the inventor analyzes that the addition of hydroquinone into the mixed solution increases the interfacial tension between the machine-made sand particles, further reduces the mutual agglomeration between the machine-made sand particles, and enables a permeable complex formed by the synergistic action among the polyaspartic acid, the toluene and the L-3, 4-dihydroxyphenylalanine to be combined with the machine-made sand more fully, thereby achieving a better filling and reinforcing effect.
Examples 7 and 8, in which polyvinyl alcohol was added in the primary modification process based on example 2, the apparent density of the machine-made sand obtained in examples 7 and 8 was increased and the index value of crushing was decreased as compared with the machine-made sand obtained in example 2, which indicates that the strength of the machine-made sand obtained in examples 7 and 8 was improved, and the inventors analyzed that polyvinyl alcohol was added to the coating solution, the polyvinyl alcohol is blended with the elastic protective film in the coating liquid, the film forming property of the polyvinyl alcohol is helpful to enhance the film structure of the elastic protective film, further improving the shaping effect of the elastic protective film on the limestone in the limestone crushing and impacting process, and the polyvinyl alcohol has certain water solubility, which is beneficial to improving the decomposability of the film formed by the coating liquid, so that the subsequent film elimination is more sufficient and thorough, further reducing the blocking effect of the coating film and the floating powder on the combination of the machine-made sand added into the concrete and the cement.
Example 9 is based on example 2, n-butanol was added in the process of preparing machine-made sand, and acetamide was added in example 10, and the apparent density of the machine-made sand prepared in examples 9 and 10 was slightly increased, the index value of crushing was decreased, and the performance values of the machine-made sand prepared in examples 9 and 10 were similar, which indicates that the strength of the machine-made sand prepared in examples 9 and 10 was increased.
Example 11 is based on example 2, not only polyvinyl alcohol and acetamide are added, but also a post-treatment processing process is performed on the finished machine-made sand, and the apparent density of the machine-made sand prepared in example 11 is improved and the crushing index value is significantly reduced compared with the machine-made sand prepared in example 2, which indicates that the strength performance of the machine-made sand prepared in example 11 is significantly improved, and the performance of the machine-made sand prepared in example 11 is better through multiple modification of limestone tailings in example 2 and addition of a substance which is helpful for improving the performance, and becomes the best embodiment of the present application.
The performance test data of application examples 1-3 in table 4 show that the concrete prepared by using the machine-made sand prepared in example 2 in application example 1 and the concrete prepared by using the machine-made sand prepared in example 11 in application example 2 have higher 3d and 28d compressive strength values and meet the compressive strength requirements of the C60 concrete, and application example 3 the concrete was prepared using the machine-made sand prepared in comparative example 1, the 3d and 28d compressive strength values of the concrete prepared in application example 3 were lower than those of the concrete prepared in application examples 1-2, therefore, the performance of the machine-made sand has important influence on the compressive strength performance of the concrete, and the machine-made sand prepared by the dry-method fine tailing machine-made sand processing method can be used for preparing high-strength concrete and has a better application prospect.
The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (8)
1. The preparation method of the dry-process fine tailing machine-made sand is characterized by comprising the following steps: the method comprises the following specific steps:
step 1, limestone tailings pretreatment:
step 1-1, collecting 500-520 parts by mass of limestone tailings, adding 80-100 parts by mass of polyacrylic acid solution into the limestone tailings, adding 20-30 parts by mass of vinyl sulfonic acid, 15-20 parts by mass of polyacrylamide hydrochloride and 30-35 parts by mass of calcium chloride aqueous solution in the mixing and stirring process, stirring at the temperature of 30-35 ℃ for 1-2h, then keeping the temperature and standing for 24h, washing with deionized water, and drying in vacuum to obtain primary modified limestone tailings;
step 1-2, mixing 15-17 parts by mass of kudzu root starch and 13-16 parts by mass of xanthan gum, gelatinizing in a water bath at 90-110 ℃, adding 7-9.5 parts by mass of N, N-methylene bisacrylamide and 7-9.5 parts by mass of sodium persulfate, and stirring for 2-3 hours to obtain a coating solution;
step 1-3, adding the coating solution into the primary modified limestone tailings, uniformly stirring, standing, cooling, and uniformly stirring again to obtain secondary modified limestone tailings;
step 2, crushing the secondary modified limestone tailings to prepare sand to obtain fine sand with the average grain size of 0.25-0.05 mm;
step 3, vibrating and screening the fine sand;
step 4, recovering and filtering the screened fine sand;
step 5, performing primary dust removal treatment and secondary dust removal treatment on the fine sand left after recovery and filtration to obtain coarse machine-made sand;
step 6, collecting the stone powder obtained by dust removal; blanking the rough manufactured machine-made sand;
and 7, soaking the crude machine-made sand in a mixed solution of 17-22 parts by mass of methyl acetate, 12-16 parts by mass of tartaric acid and 20-30 parts by mass of ethanol, uniformly stirring, standing for 6 hours, carrying out solid-liquid separation, discharging upper-layer liquid, washing settled sand with clear water, and drying the settled sand to obtain dry-process fine tailing machine-made sand.
2. The method for preparing the machine-made sand from the fine dry tailings according to claim 1, which is characterized in that: 0.5-0.7 part by mass of polyvinyl alcohol is also added in the step 1-2.
3. The method for preparing the machine-made sand from the fine dry tailings according to claim 1, which is characterized in that: 0.3-0.5 part by mass of n-butanol or acetamide is also added in the step 7.
4. The method for preparing the machine-made sand from the fine dry tailings according to claim 1, which is characterized in that: the step 7 also comprises a process for post-treating the finished machine-made sand, and the method specifically comprises the following steps: adding 30-35 parts by mass of toluene, 7-10 parts by mass of coupling agent, 10-15 parts by mass of polyaspartic acid and 12-15 parts by mass of L-3, 4-dihydroxyphenylalanine into the dry-process refined tailing machine-made sand, uniformly mixing, reacting at the temperature of 100-.
5. The method for preparing the dry-process fine tailing machine-made sand according to claim 4, which is characterized in that: the coupling agent is vinyl trimethoxy silane or vinyl tri (beta-methoxy ethoxy) silane.
6. The method for preparing the dry-process fine tailing machine-made sand according to claim 4, which is characterized in that: and in the step 7, 0.2-0.5 part by mass of hydroquinone is also added in the post-treatment process of the finished machine-made sand.
7. The utility model provides a dry process fine work tailing ore deposit system sand which characterized in that: the sand is prepared by the method for preparing the dry-process fine tailings machine-made sand according to any one of claims 1 to 6.
8. A high-strength concrete is characterized in that: the concrete mixture is prepared from the following raw materials in parts by mass: 401 parts of cement 381-containing materials, 657 parts of machine-made sand 637-containing materials, 1060 parts of broken stones 1040-containing materials, 175 parts of water 155-containing materials, 82-100 parts of mineral powder, 82-100 parts of fly ash and 12.5-15.5 parts of polycarboxylic acid high-performance water reducing agent; the machine-made sand is a fine dry tailings machine-made sand obtained by the production method of any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111632952.1A CN114349380B (en) | 2021-12-28 | 2021-12-28 | Preparation method of dry-process fine-tailings machine-made sand and high-strength concrete containing machine-made sand |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111632952.1A CN114349380B (en) | 2021-12-28 | 2021-12-28 | Preparation method of dry-process fine-tailings machine-made sand and high-strength concrete containing machine-made sand |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114349380A CN114349380A (en) | 2022-04-15 |
| CN114349380B true CN114349380B (en) | 2022-07-19 |
Family
ID=81103934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111632952.1A Active CN114349380B (en) | 2021-12-28 | 2021-12-28 | Preparation method of dry-process fine-tailings machine-made sand and high-strength concrete containing machine-made sand |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114349380B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110372243A (en) * | 2019-08-15 | 2019-10-25 | 广州铁诚工程质量检测有限公司 | Machine-made Sand and preparation method thereof and the concrete prepared using the Machine-made Sand |
| CN111393111A (en) * | 2020-03-28 | 2020-07-10 | 德清高盛交通科技有限公司 | Full-machine-made sand plastering mortar with limestone as aggregate and preparation method thereof |
| CN111825396A (en) * | 2020-07-31 | 2020-10-27 | 亚泰集团长春建材有限公司 | Concrete based on limestone tailings as raw material and preparation method thereof |
| AU2021101922A4 (en) * | 2021-04-14 | 2021-06-03 | China Construction Ready Mixed Concrete Co.Ltd. | A machine-made sand green concrete and a preparation method thereof |
| CN113480267A (en) * | 2021-08-05 | 2021-10-08 | 高县卓越商品混凝土有限公司 | High-performance concrete applying machine-made sand and preparation method thereof |
-
2021
- 2021-12-28 CN CN202111632952.1A patent/CN114349380B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN114349380A (en) | 2022-04-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113213787B (en) | Production process for preparing alkali cementing material from coal gangue | |
| CN101767960A (en) | Recycled concrete coarse aggregate modified processing method | |
| CN103588449A (en) | Method for preparing steam-pressing bricks from multiple raw mineral materials | |
| CN111747672B (en) | Superfine modified phosphorus slag powder and superfine composite admixture for concrete | |
| CN108314375B (en) | Regenerated viscose mortar and preparation method thereof | |
| CN113087471B (en) | Recycled concrete and preparation method thereof | |
| CN110372285A (en) | A kind of Organic-inorganic composite rubber regeneration concrete | |
| CN114308373A (en) | Method for utilizing graphite ore full resources | |
| WO2018137596A1 (en) | Method for preparing thinned ceramic additive using refuse leachate | |
| CN103553503A (en) | Preparation method of C50 recycled concrete of low gelling material | |
| CN114349380B (en) | Preparation method of dry-process fine-tailings machine-made sand and high-strength concrete containing machine-made sand | |
| CN107056202A (en) | Carbonization slag cement prepares accelerator and its application process of low-carbon binder materials | |
| CN113185170B (en) | Method for modifying gangue aggregate based on microbial induction technology | |
| CN114538881A (en) | Modified plant fiber-mineral composite soil improvement material and preparation method thereof | |
| CN110282942A (en) | A kind of concrete mix and its production technology | |
| CN112374838B (en) | Lithium slag concrete and preparation method thereof | |
| CN111943545B (en) | Artificial sand and preparation method thereof | |
| CN108218259A (en) | Using electrolytic manganese residues the method for concrete and concrete prepared therefrom are prepared as retarder | |
| CN116217109B (en) | Artificial color sand and preparation method thereof | |
| CN115745505B (en) | Ecological early-strength impervious dry-mixed mortar and preparation method thereof | |
| CN111892365B (en) | Iron tailing based building block and preparation method thereof | |
| CN114083693A (en) | Method for quickly identifying and compounding engineering waste soil | |
| CN107285731B (en) | Ball clay as high-grade sanitary ceramic raw material and production method thereof | |
| CN102503207B (en) | Preparation method of pipe pile tail slurry concrete composite admixture | |
| CN115784676B (en) | Ecological slope protection brick and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |