Rapid detection method and application of residual flocculant types in machine-made sand

Abstract

The present disclosure provides a rapid detection method and use of the type of residual flocculant in machine-made sand, the method comprising: S1, fully mixing the machine-made sand to be tested with distilled water to obtain a mixed solution; S2, filtering the mixed solution through a stainless steel screen to obtain a sample solution to be tested; S3, preparing a first type standard solution, a second type standard solution, a third type standard solution and a fourth type standard solution of a certain concentration, a total of four types of standard solutions; S4, adding the sample solution to be tested to the four types of standard solutions respectively, and observing the reaction phenomena respectively; S5, according to the reaction phenomena, quickly determining the type of residual flocculant in the machine-made sand to be tested. The method disclosed in the present disclosure can quickly detect the type of residual flocculant in machine-made sand at low cost, high efficiency and universality, and help on-site technicians to provide targeted solutions.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and in particular to a method for quickly detecting the types of residual flocculants in machine-made sand and its application. Background Art

[0002] Sand and gravel aggregate is one of the important raw materials required for the preparation of concrete, and its excellent quality is an important guarantee for high-quality concrete projects. With the gradual increase in concrete consumption in my country, the shortage of high-quality natural aggregates such as natural river sand has restricted the progress of the concrete industry. In recent years, machine-made sand obtained by screening, shaping and cleaning crushed rocks has gradually been used in the field of building materials, which has solved the problem of insufficient supply of natural river sand to a certain extent. However, due to imperfect standards and specifications, the need to improve production processes, and insufficient testing methods, machine-made sand aggregates are still lacking in the preparation of high-quality concrete. The most important problem is that the residual flocculants in the machine-made sand significantly reduce the fluidity and slump loss of concrete.

[0003] The production of artificial sand usually requires a series of processes such as washing, crushing, screening, shaping, and re-washing of rocks, which will consume a lot of water resources. However, the national standard GB 51186 "Design Specifications for Artificial Sand and Gravel Aggregate Plants" clearly states that the production process design of ore washing operations or wet sand making operations should use return water; when the original ore contains a high amount of mud (soil), a mud (soil) removal process should be adopted. At this time, in order to reduce costs and improve water circulation efficiency, the sand and gravel plant may discharge sewage containing mud and sand into a sedimentation tank, use flocculants to quickly flocculate and precipitate mud and sand and other substances, and then extract the supernatant to wash the artificial sand. Because the artificial sand plant adds flocculants at random during the production process, different levels of flocculants remain in the artificial sand, affecting the fluidity of the concrete. Through a large number of experiments, it is concluded that when the residual amount of polyacrylamide flocculants in the machine-made sand reaches 0.003% of the mass of the sand (based on the mixing water amount, the aqueous solution concentration is 0.018%), the fluidity of the mortar will be significantly reduced; when the residual amount of polyacrylamide flocculants in the machine-made sand reaches 0.009% of the mass of the sand (based on the mixing water amount, the aqueous solution concentration is 0.054%), the optimal amount of polycarboxylic acid water reducer will be ineffective; when the residual amount of polyacrylamide flocculants in the machine-made sand further increases, the fluidity of the mortar will further deteriorate, which will seriously affect the pumpability of the concrete. In addition, although polyacrylamide flocculants are more commonly used in the field of machine-made sand preparation, some machine-made sand manufacturers may also use other types of flocculants, such as cationic polyacrylamide, polyaluminum chloride, polyferric sulfate, etc., for the purpose of controlling costs, accelerating flocculation and increasing production capacity. However, this will not only cause a decrease in the fluidity of concrete, but also cause other problems. For example, polyaluminium chloride contains a large amount of chloride ions, which may induce steel corrosion; polyferric sulfate contains a large amount of sulfate ions, which may accelerate the coagulation and hardening of concrete, resulting in insufficient concrete strength.

[0004] The content of flocculants attached to machine-made sand is unknown, and more importantly, the type is unknown. The molecular structure and performance of different types of flocculants are significantly different, and their impact on concrete performance is very complex. Developing a detection method for only a single flocculant will ignore the impact of other types of flocculants. More importantly, it is necessary to clarify the type of flocculants in machine-made sand so that targeted solutions can be taken. If this can be achieved, the quality of machine-made sand can be better evaluated, which can not only ensure the quality of concrete projects, but also help improve the relevant standards and specifications in the field of machine-made sand detection.

[0005] Therefore, there is an urgent need to develop a low-cost, high-efficiency, and universal method for detecting the types of residual flocculants in artificial sand, which can be used to quickly determine whether there are flocculants remaining in the artificial sand at the construction site, and at the same time determine the types of residual flocculants, so as to help on-site technicians provide targeted solutions. Summary of the invention

[0006] In view of this, the first aspect of the present disclosure provides a method for rapid detection of the type of residual flocculant in artificial sand, comprising: S1, fully mixing the artificial sand to be tested with distilled water to obtain a mixed solution; S2, filtering the mixed solution through a stainless steel sieve to obtain a sample solution to be tested; S3, preparing four types of standard solutions, namely, a first type of standard solution, a second type of standard solution, a third type of standard solution and a fourth type of standard solution with a certain concentration; S4, adding the sample solution to be tested into the four types of standard solutions, respectively, and observing the reaction phenomena respectively; S5, based on the reaction phenomena, quickly determining the type of residual flocculant in the artificial sand to be tested.

[0007] According to an embodiment of the present disclosure, determining the type of residual flocculant in the machine-made sand to be tested in S5 includes: if a flocculent precipitate is generated in the first type of standard solution to which the sample solution to be tested is added, then it is determined that the type of residual flocculant in the machine-made sand to be tested includes anionic polyacrylamide; if discoloration occurs in the second type of standard solution to which the sample solution to be tested is added, then it is determined that the type of residual flocculant in the machine-made sand to be tested includes cationic polyacrylamide; if a white precipitate is generated in the third type of standard solution to which the sample solution to be tested is added, then it is determined that the type of residual flocculant in the machine-made sand to be tested includes polyaluminum chloride; if a precipitate is generated in the fourth type of standard solution to which the sample solution to be tested is added and accompanied by discoloration, then it is determined that the type of residual flocculant in the machine-made sand to be tested includes polyferric sulfate.

[0008] According to an embodiment of the present disclosure, determining the type of residual flocculant in the machine-made sand to be tested in S5 also includes: if the four types of standard solutions to which the sample solution to be tested is added have no obvious reaction phenomenon, it is determined that the machine-made sand to be tested does not contain anionic polyacrylamide, cationic polyacrylamide, polyaluminum chloride and polyferric sulfate flocculants.

[0009] According to an embodiment of the present disclosure, the mass ratio of the machine-made sand to be tested to distilled water in S1 is 1:2-1:4.

[0010] According to an embodiment of the present disclosure, filtering through a stainless steel sieve in S2 includes: filtering the mixed solution through at least two stainless steel sieves with different pore sizes in sequence, the pore sizes of the at least two stainless steel sieves with different pore sizes decreasing in sequence.

[0011] According to an embodiment of the present disclosure, filtering through a stainless steel sieve in S2 includes: filtering the mixed solution through 200 mesh, 300 mesh, 500 mesh and 1000 mesh stainless steel sieves in sequence to obtain a sample solution to be tested.

[0012] According to an embodiment of the present disclosure, the concentrations of the four types of standard solutions in S3 are 1 g / L to 5 g / L.

[0013] According to an embodiment of the present disclosure, the first type of standard solution in S3 is selected from one of copper sulfate, copper chloride, ferrous sulfate, ferrous sulfate, and nickel ammonium sulfate solution; the concentration of the first type of standard solution is 3.5 g / L~5 g / L;

[0014] The second type of standard solution is selected from one of weak acid brilliant blue, weak acid scarlet, and phthalocyanine blue solutions; the concentration of the second type of standard solution is 1g / L~2g / L;

[0015] The third type of standard solution is selected from one of silver nitrate, copper sulfate, ferric chloride, and EDTA solution; the concentration of the third type of standard solution is 3g / L~4.5g / L;

[0016] The fourth type of standard solution is selected from one of iron hydroxide colloid, aluminum hydroxide colloid, silver iodide colloid, starch colloid, and metakaolin colloid; the concentration of the fourth type of standard solution is 1g / L~1.5g / L.

[0017] According to an embodiment of the present disclosure, the mass of the sample solution added in S4 accounts for 20% to 50% of the mass of the four types of standard solutions.

[0018] The second aspect of the present disclosure provides a use of the aforementioned rapid detection method for the type of residual flocculant in machine-made sand, which is used to adjust the additives of concrete or the scope of use thereof according to the determined type of residual flocculant in the machine-made sand to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0020] Figure 1 A flowchart schematically shows a method for quickly detecting the type of residual flocculant in machine-made sand according to an embodiment of the present disclosure;

[0021] Figure 2 A schematic diagram of a picture showing a copper sulfate solution having a clumping or flocculent precipitate according to an embodiment of the present disclosure;

[0022] Figure 3 A picture schematically shows the decolorization phenomenon of the weak acid blue (RAWL) solution according to an embodiment of the present disclosure;

[0023] Figure 4 A picture schematically shows a white precipitate appearing in a silver nitrate solution according to an embodiment of the present disclosure;

[0024] Figure 5 The picture schematically shows the discoloration and reddish-brown precipitation of ferric hydroxide colloid according to the embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0026] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0027] In order to solve the problem that unknown flocculants remain in the machine-made sand due to the machine-made sand production process, thereby affecting the workability and strength of concrete, and to avoid the problem of waste of raw materials due to residual flocculants in the machine-made sand, the present disclosure provides a rapid detection method for the types of residual flocculants in the machine-made sand, which utilizes the flocculation characteristics of different types of flocculants on harmful ions or harmful media to achieve the purpose of rapid detection of whether flocculants remain in the machine-made sand under laboratory conditions on the engineering site. The present disclosure aims to improve the quality of machine-made sand aggregates on the engineering site, thereby ensuring the quality of concrete engineering and reducing waste of raw material resources.

[0028] This disclosure provides a rapid detection method for the type of residual flocculant in machine-made sand, see Figure 1 , including: S1, fully mixing the machine-made sand to be tested with distilled water to obtain a mixed solution; S2, filtering the mixed solution through a stainless steel mesh to obtain a sample solution to be tested; S3, preparing four types of standard solutions, namely, a first type of standard solution, a second type of standard solution, a third type of standard solution and a fourth type of standard solution with certain concentrations; S4, adding the sample solution to be tested into the four types of standard solutions respectively, and observing the reaction phenomena respectively; S5, according to the reaction phenomena, quickly determining the type of residual flocculant in the machine-made sand to be tested.

[0029] The main purpose of the present disclosure is to provide a rapid detection method for the type of residual flocculant in machine-made sand, in order to evaluate the quality of machine-made sand aggregate at the construction site and help on-site technicians quickly determine solutions. Due to the large number of flocculants, a single method cannot detect different types of flocculants at the same time. The method disclosed in the present disclosure first mixes the machine-made sand to be tested with distilled water and then filters to remove solid particles, and the flocculant is dissolved in the sample solution to be tested. Four types of standard solutions are also prepared, and the sample solution to be tested is added to the standard solution. The reaction phenomenon of the sample solution to be tested and the standard solution is observed respectively, so as to obtain the type of flocculant in the sample solution to be tested, that is, the type of flocculant remaining in the machine-made sand to be tested.

[0030] The method disclosed in the present invention determines the type of unknown flocculant remaining in the machine-made sand by utilizing the flocculation effect of the flocculant on harmful ions or harmful media and the obvious reaction phenomenon. This is completely different from the method of testing the viscosity, absorbance, and turbidity of the flocculant aqueous solution in the disclosed test method, and is also different from the method of testing the fluidity change of mortar or cement paste, and is an innovative test method. In addition, the detection method involved in the present invention is not limited to the need for high-value detection equipment (such as ion chromatograph, spectrophotometer, etc.), nor is it limited to a specific flocculant, but can simultaneously achieve rapid detection of multiple types of flocculants.

[0031] On the basis of the above embodiment, determining the type of residual flocculant in the machine-made sand to be tested in S5 includes: if a flocculent precipitate is generated in the first type of standard solution to which the sample solution to be tested is added, it is determined that the type of residual flocculant in the machine-made sand to be tested includes anionic polyacrylamide; if discoloration occurs in the second type of standard solution to which the sample solution to be tested is added, it is determined that the type of residual flocculant in the machine-made sand to be tested includes cationic polyacrylamide; if a white precipitate is generated in the third type of standard solution to which the sample solution to be tested is added, it is determined that the type of residual flocculant in the machine-made sand to be tested includes polyaluminum chloride; if a precipitate is generated in the fourth type of standard solution to which the sample solution to be tested is added and accompanied by discoloration, it is determined that the type of residual flocculant in the machine-made sand to be tested includes polyferric sulfate.

[0032] In S3, the first standard solution is selected from one of copper sulfate, copper chloride, ferric sulfate, ferrous sulfate, and nickel ammonium sulfate solution; the second standard solution is selected from one of weak acid brilliant blue, weak acid scarlet, and phthalocyanine blue solution; the third standard solution is selected from one of silver nitrate, copper sulfate, ferric chloride, and EDTA solution; the fourth standard solution is selected from one of iron hydroxide colloid, aluminum hydroxide colloid, silver iodide colloid, starch colloid, and metakaolin colloid; the concentration of the fourth standard solution is 1g / L~1.5g / L. Anionic polyacrylamide reacts with copper sulfate to form a precipitate. If the solution sample to be tested contains anionic polyacrylamide, it reacts with the first standard solution to form a flocculent precipitate. Cationic polyacrylamide can decolorize weak acid blue (RAWL) solution. If the solution sample to be tested contains cationic polyacrylamide, it reacts with the second standard solution to produce a decolorization phenomenon. Chloride ions react with silver nitrate solution to form a precipitate. If the solution sample to be tested contains polyaluminum chloride, it reacts with the third standard solution to form a white precipitate. Polyferric sulfate reacts with ferric hydroxide colloid to form a precipitate. If the solution sample to be tested contains polyferric sulfate, it will react with the fourth type standard solution to form a reddish-brown precipitate accompanied by decolorization.

[0033] On the basis of the above embodiment, determining the type of residual flocculant in the machine-made sand to be tested in S5 also includes: if the four types of standard solutions to which the sample solution to be tested is added have no obvious reaction phenomenon, it is determined that the machine-made sand to be tested does not contain anionic polyacrylamide, cationic polyacrylamide, polyaluminum chloride and polyferric sulfate flocculants.

[0034] If the solution sample to be tested does not contain the above four types of flocculants, it will not react with the first type of standard solution, the second type of standard solution, the third type of standard solution and the fourth type of standard solution. Common flocculants are also polyacrylamide (anionic), polyacrylamide (cationic), polyaluminum chloride and polyferric sulfate. The method disclosed in this disclosure can cover most of the actual detection range.

[0035] The method disclosed in the present invention can achieve the detection purpose by using only a few common liquids, and is easy to operate and takes very little time. It is completely different from existing methods (including testing the viscosity, absorbance, turbidity, etc. of aqueous solutions), and greatly improves the detection efficiency.

[0036] On the basis of the above embodiment, the mass ratio of the machine-made sand to be tested to the distilled water in S1 is 1:2-1:4.

[0037] A larger amount of distilled water is used, which is conducive to completely immersing the machine-made sand sample and ensuring that the distilled water and the machine-made sand sample are fully mixed. A glass rod is used to stir the mixture fully so as to better dissolve the residual flocculant on the machine-made sand to be tested.

[0038] Based on the above embodiment, filtering through a stainless steel mesh in S2 includes: filtering the mixed solution through at least two stainless steel meshes with different pore sizes in sequence, wherein the pore sizes of the at least two stainless steel meshes with different pore sizes decrease in sequence.

[0039] Filtering the mixed solution multiple times is beneficial to better remove the machine-made sand solids and avoid affecting subsequent sedimentation.

[0040] On the basis of the above embodiment, filtering through a stainless steel sieve in S2 includes: filtering the mixed solution through 200 mesh, 300 mesh, 500 mesh and 1000 mesh stainless steel sieves in sequence to obtain a sample solution to be tested.

[0041] Preferably, 200 mesh, 300 mesh, 500 mesh and 1000 mesh stainless steel screens are used for filtering in sequence, so that the machine-made sand solids can be removed in sequence in stages, and a good solid removal effect is achieved.

[0042] Based on the above embodiment, the concentrations of the four types of standard solutions in S3 are 1 g / L to 5 g / L.

[0043] According to the approximate range of residual flocculants in machine-made sand, the concentration range of the response sample solution can be calculated. Therefore, determining the concentration of the standard solution within the above range is conducive to more clear observation of precipitation, decolorization and other phenomena.

[0044] On the basis of the above embodiment, the concentration of the copper sulfate solution in S3 is 3.5g / L~5g / L; the concentration of the weak acid blue solution is 1g / L~2g / L; the concentration of the silver nitrate solution is 3g / L~4.5g / L; and the concentration of the ferric hydroxide colloid is 1g / L~1.5g / L.

[0045] Preferably, the concentration of copper sulfate solution is in the above range, which is conducive to the anionic polyacrylamide of very low concentration fully complexing with copper ion in solution, and promotes the phase separation phenomenon and generation precipitation of complex in solution. The concentration of weakly acidic blue solution is in the above range, which is conducive to the cationic polyacrylamide of very low concentration giving full play to the effect of electrical neutralization and adsorption bridging, so that the weakly acidic blue dye particles are destabilized, flocculated and reach the purpose of decolorization from water. The concentration of silver nitrate solution is in the above range, which is conducive to the complete precipitation of chloride ions and hydroxide ions in the polyaluminium chloride solution. The concentration of iron hydroxide colloid is in the above range, which is conducive to observing a sufficient amount of coagulation caused by iron ions and sulfate ions under the premise that coagulation does not occur in the colloid itself.

[0046] Based on the above embodiment, the mass of the sample solution added in S4 accounts for 20% to 50% of the mass of the four types of standard solutions.

[0047] The sample solution to be tested should not be added too little, so as to avoid too little precipitation to observe the precipitation phenomenon, or difficult to observe the decolorization phenomenon. The sample solution to be tested should not be added too much, so as to avoid introducing too many particles smaller than 1000 mesh in the machine-made sand to affect the observation of the reaction phenomenon.

[0048] The present disclosure also provides a use of the aforementioned rapid detection method for the type of residual flocculant in the machine-made sand, which is used to adjust the additives of concrete or the scope of use thereof according to the determined type of residual flocculant in the machine-made sand to be tested.

[0049] Specifically, when the test result shows that there is no flocculant residue in the machine-made sand to be tested, there are no special restrictions when it is used to prepare concrete; when the test result shows that anionic or cationic polyacrylamide remains in the machine-made sand to be tested, the on-site technicians are prompted to adjust the amount of water reducer in the concrete in time to ensure the fluidity of the concrete; when the test result shows that polyaluminum chloride remains in the machine-made sand to be tested, the on-site technicians are prompted that this batch of machine-made sand cannot be used to prepare reinforced concrete components, but can only be used to prepare plain concrete components, such as guardrails, curbs, etc.; when the test result shows that polyferric sulfate remains in the machine-made sand to be tested, the on-site technicians are prompted to adjust the mix ratio and add appropriate retarders when preparing concrete components with this batch of machine-made sand to avoid premature setting of the concrete and resulting in subsequent strength reduction.

[0050] The present disclosure is further described below through specific implementation methods. The rapid detection method and use of the type of residual flocculant in the above-mentioned machine-made sand are specifically described in the following examples. However, the following examples are only used to illustrate the present disclosure, and the scope of the present disclosure is not limited thereto.

[0051] The rapid detection method of the type of residual flocculant in the machine-made sand of this embodiment comprises the following steps:

[0052] S1: Prepare 1000g of the machine-made sand sample to be tested, put the machine-made sand sample to be tested into a beaker, add 2000g of distilled water, and stir well.

[0053] S2: The sample solution is then passed through 200 mesh, 300 mesh, 500 mesh and 1000 mesh stainless steel sieves in sequence to obtain the sample solution to be tested.

[0054] S3: Prepare 4 standard solutions of 3 g / L copper sulfate solution (A standard solution), weak acid blue (RAWL) solution (B standard solution), silver nitrate solution (C standard solution) and ferric hydroxide colloid (D standard solution), and prepare 400 ml of each in a beaker.

[0055] S4: Add 20 ml of the sample solution to be tested into each standard solution beaker, stir thoroughly, and observe the reaction phenomenon.

[0056] S5: Determine the type of flocculant remaining in the machine-made sand based on the reaction phenomena in each beaker.

[0057] S51: When there is no obvious reaction in each beaker, it is determined that there is no flocculant residue in the machine-made sand sample;

[0058] S52: When agglomerates or flocculent precipitates appear in the A standard solution beaker, Figure 2 As shown, it indicates that there are anionic polyacrylamide type flocculants residues in the machine-made sand sample;

[0059] S53: When discoloration occurs in the B standard solution beaker, Figure 3 As shown, it indicates that there are cationic polyacrylamide type flocculants residues in the machine-made sand sample;

[0060] S54: When a white precipitate appears in the C standard solution beaker, Figure 4 As shown, it indicates that there are polyaluminium chloride type flocculants residues in the machine-made sand sample;

[0061] S55: When discoloration and reddish brown precipitation appear in the D standard solution beaker, Figure 5 As shown, it indicates that there are polyferric sulfate type flocculants residues in the machine-made sand sample;

[0062] S6: Based on the different types of flocculant residues in machine-made sand, the concrete mix ratio recommendations for machine-made sand are given:

[0063] S61: For machine-made sand with no detected residual flocculant, there is no restriction on its use in concrete preparation;

[0064] S62: For machine-made sand with residual flocculants of anionic or cationic polyacrylamide, the on-site technicians are prompted to adjust the amount of water reducing agent in the concrete in time to ensure the fluidity of the concrete;

[0065] S63: For machine-made sand with polyaluminium chloride as the residual flocculant, the on-site technicians are reminded that this batch of machine-made sand cannot be used to prepare reinforced concrete components, but can only be used to prepare plain concrete components, such as guardrails, curbstones, etc.;

[0066] S64: For artificial sand in which the type of residual flocculant detected is polyferric sulfate, the on-site technicians are reminded that when preparing concrete components with this batch of artificial sand, they need to adjust the mix ratio and add appropriate retarders to ensure that the slump loss of the concrete is small.

[0067] Specifically, this embodiment combines the two kinds of machine-made sand detection tests containing unknown flocculants in previous tests, obtains the machine-made sand samples and the solution samples to be tested according to the description in the specific implementation plan, and observes that the 1# solution sample to be tested reacts with the standard solution A to produce flocculent precipitation, and it is determined that it contains anionic polyacrylamide. It is observed that the 2# solution sample to be tested causes the standard solution B to undergo a decolorization reaction, and it is determined that it contains cationic polyacrylamide.

[0068] Based on the influence of anionic or cationic polyacrylamide flocculants on the fluidity of concrete, on-site technicians are guided to increase the dosage of water reducer to ensure that the slump loss of fresh concrete is excessive when these two types of machine-made sand are used to prepare concrete.

[0069] In summary, the present disclosure provides a rapid detection method for the type of residual flocculant in machine-made sand, which is suitable for rapid detection of whether there is residual flocculant in the machine-made sand at the construction site, and at the same time determines the type of residual flocculant in the machine-made sand, prompting on-site technicians to adjust the concrete mix ratio in a targeted manner to ensure the quality of concrete engineering. Therefore, the present disclosure has at least the following beneficial effects:

[0070] 1. The detection method developed in the present disclosure can quickly determine whether there is residual flocculant in the machine-made sand under the premise of the type of residual flocculant in the machine-made sand. The method develops the flocculation effect of the flocculant on harmful ions or harmful media to determine whether there is residual flocculant. Only a few common liquids can be used to achieve the purpose of detection. The method disclosed in the present disclosure is easy to operate, takes very little time, and is completely different from existing methods (including testing the viscosity, absorbance, turbidity, etc. of aqueous solutions), which greatly improves the detection efficiency.

[0071] 2. This disclosure plays a positive role in promoting the quality control of machine-made sand. By realizing rapid detection of the types of residual flocculants in machine-made sand at the construction site, it provides a convenient and practical method for owners and supervisors, which helps to strengthen the supervision and management of the quality of machine-made sand before the industry provides standardized detection methods.

[0072] 3. The disclosure has a positive effect on reducing construction costs. By quickly detecting and determining whether there are flocculants remaining in the machine-made sand, it can provide a reference for on-site technicians to adjust the concrete mix ratio, reduce raw material quality problems caused by flocculants, and thus solve the cost increase problem caused by unqualified materials.

[0073] 4. The present invention has made outstanding contributions to improving engineering quality. It has realized the rapid detection of the types of residual flocculants in the machine-made sand at the engineering site, greatly reducing the concrete performance defects caused by the poor quality of machine-made sand, and further reducing the engineering quality problems caused by poor concrete performance, making outstanding contributions to the quality assurance of concrete engineering and the improvement of structural durability.

[0074] 5. This disclosure also provides the application scope for different types of flocculants contained in machine-made sand, which has not been mentioned in similar disclosures. The application of related technologies can further improve the application scope of machine-made sand of different qualities and help enterprises make more reasonable production decisions.

[0075] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A rapid detection method for the type of residual flocculant in machine-made sand, characterized in that: include: S1, fully mix the machine-made sand to be tested with distilled water to obtain a mixed solution; S2, filtering the mixed solution through a stainless steel mesh to obtain a sample solution to be tested; S3, prepare a total of four types of standard solutions of a certain concentration, namely, a first type standard solution, a second type standard solution, a third type standard solution and a fourth type standard solution; the first type standard solution is selected from one of copper sulfate, copper chloride, ferric sulfate, ferrous sulfate and nickel ammonium sulfate solution; the second type standard solution is selected from one of weak acid brilliant blue, weak acid scarlet and phthalocyanine blue solution; the third type standard solution is selected from one of silver nitrate, copper sulfate, ferric chloride and EDTA solution; the fourth type standard solution is selected from one of iron hydroxide colloid, aluminum hydroxide colloid, silver iodide colloid, starch colloid and metakaolin colloid; S4, adding the sample solution to be tested into the four types of standard solutions respectively, and observing the reaction phenomena respectively; S5, according to the reaction phenomenon, quickly determine the type of residual flocculant in the machine-made sand to be tested; Among them, the types of residual flocculants in the machine-made sand to be tested are determined in S5, including: If flocculent precipitation is generated in the first type of standard solution to which the sample solution to be tested is added, it is determined that the type of residual flocculant in the machine-made sand to be tested includes anionic polyacrylamide; If the second type of standard solution to which the sample solution to be tested is added produces a discoloration phenomenon, it is determined that the type of residual flocculant in the machine-made sand to be tested includes cationic polyacrylamide; If a white precipitate is generated in the third type standard solution to which the sample solution to be tested is added, it is determined that the types of residual flocculants in the machine-made sand to be tested include polyaluminium chloride; If a reddish-brown precipitate is generated in the fourth type standard solution to which the sample solution to be tested is added, accompanied by a discoloration phenomenon, it is determined that the types of residual flocculants in the machine-made sand to be tested include polyferric sulfate.

2. The rapid detection method for the type of residual flocculant in machine-made sand according to claim 1 is characterized in that: Determining the type of residual flocculant in the machine-made sand to be tested in S5 also includes: If the four types of standard solutions to which the sample solution to be tested is added have no obvious reaction phenomenon, it is determined that the machine-made sand to be tested does not contain the anionic polyacrylamide, the cationic polyacrylamide, the polyaluminium chloride and the polyferric sulfate flocculant.

3. The rapid detection method for residual flocculant types in machine-made sand according to claim 1 is characterized in that: The mass ratio of the machine-made sand to be tested and the distilled water described in S1 is 1:2~1:

4.

4. The rapid detection method for residual flocculant types in machine-made sand according to claim 1 is characterized in that: The filtering through the stainless steel screen in S2 comprises: The mixed solution is filtered sequentially through at least two stainless steel meshes with different pore sizes, and the pore sizes of the at least two stainless steel meshes with different pore sizes decrease sequentially.

5. The rapid detection method for residual flocculant types in machine-made sand according to claim 4 is characterized in that: The filtering through the stainless steel screen in S2 comprises: The mixed solution was filtered through 200-mesh, 300-mesh, 500-mesh and 1000-mesh stainless steel sieves in sequence to obtain a sample solution to be tested.

6. The rapid detection method for residual flocculant types in machine-made sand according to claim 1 is characterized in that: The concentrations of the four types of standard solutions described in S3 are 1 g / L to 5 g / L.

7. The rapid detection method for residual flocculant types in machine-made sand according to claim 6 is characterized in that: The concentration of the first type of standard solution in S3 is 3.5g / L~5g / L; The concentration of the second type of standard solution is 1g / L~2g / L; The concentration of the third type of standard solution is 3g / L~4.5g / L; The concentration of the fourth type standard solution is 1 g / L to 1.5 g / L.

8. The rapid detection method for residual flocculant types in machine-made sand according to claim 1 is characterized in that: The mass of the sample solution added in S4 accounts for 20% to 50% of the mass of the four types of standard solutions.

9. Use of the method for rapid detection of residual flocculant types in machine-made sand according to any one of claims 1 to 8, for adjusting concrete additives or their use range according to the determined residual flocculant types in the machine-made sand to be tested.

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