A water-reducing agent for soil press filtration

Abstract

The application provides a pressure filtration soil water-reducing agent, which comprises component I and component II. The total weight of the component I is 100 parts, and the component I comprises the following raw materials: 20-30 parts of water-reducing agent, 0.005-0.01 parts of flocculating agent, 5-8 parts of organic silicon water-repellent agent, 5-8 parts of air entraining agent, 3-5 parts of emulsifier, 1-2 parts of suspension dispersing agent, and the rest is water. The component II is quicklime. After the pressure filtration soil water-reducing agent is added to the aggregate washing mud, flocculation is complete, and the sedimentation is loose. The filtration speed is fast when the deposited sludge is subjected to solid-liquid separation in a common plate-frame filter press, the water content of the pressure filtration soil can be reduced to below 15%, the volume and weight are reduced, and transportation and subsequent disposal and utilization are facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resource and environment, and particularly relates to a precipitation agent for filter cake. BACKGROUND

[0002] Sand aggregate is the most used raw material in the composition of concrete and cement products, and is the largest product in the exploitation and consumption of natural resources, and its demand is rigid and indispensable. With the continuous expansion of infrastructure scale in China in recent years, the market demand for sand continues to grow. Due to the restriction on the exploitation of natural sand, the scale of the manufactured sand industry is rapidly growing. The provinces in the lower reaches of the Yangtze River mostly use wet process to produce manufactured sand, and in the process, water washing is used to wash away the mud and powder attached to the raw materials. Therefore, the treatment of wastewater and sludge produced by water-washed sand manufactured sand has become a problem. The general treatment process is as follows: the wastewater enters the neutralization tank and is continuously stirred by the stirrer to achieve homogeneity, and then is lifted to the sludge rapid settling tank by the lifting pump. In the rapid settling tank, flocculating agent is added to rapidly separate water and sludge, and then the water overflows to the clean water storage and recycling pool for recycling. The settled sludge is sent to the filter press for solid-liquid separation, and the filter cake is transported out.

[0003] The brick making process of filter cake is to crush the filter cake after filtration, mix and stir with other materials in a solid state, press and form, and autoclave curing, to comprehensively utilize various components to produce tailings brick products, to meet the requirements of "reduction, immobilization, harmlessness and resource utilization". According to the current brick making process, the proportion of filter cake added is up to 70%.

[0004] There are certain requirements for the moisture content of using filter cake to make bricks. The moisture content of the mixture of filter cake, undersize material, cement, etc. should not be more than 10%. However, due to the influence of technology and treatment efficiency, the moisture content of filter cake treated by flocculating agent is generally more than 20%, which limits the use of filter cake. In addition, the high moisture content of filter cake will lead to large volume, difficulty in transportation and storage, strong plasticity, easy to form clumps in the stirring process, and easy to adhere to the equipment, making it difficult to mix other materials and filter cake evenly. In addition, high water content will lead to low water-binder ratio and low strength of the bricks, easy to break and have missing corners during autoclave curing, and the quality of the bricks will decrease. Large burning loss will lead to large voids in the bricks, which are easy to form waste bricks and increase the breakage rate of the products.

[0005] In addition, during the treatment process of wastewater and sludge produced by water-washed sand manufactured sand, a large amount of flocculating agent is added. After the manufactured sand is washed by the recycled sand washing water, the surface of the manufactured sand will adsorb some flocculating agent in the sand washing water, which will cause poor fluidity, fast loss of slump, fast setting time, poor durability after hardening, and other problems when used for concrete preparation, causing great harm to the quality of the concrete. SUMMARY

[0006] To solve the problems in the background art, the application provides a precipitation agent for pressure filtration soil, which has the advantages of small dosage, complete flocculation, rapid filtration, loose sediment, great reduction of water content of the pressure filtration soil, strong adaptability in sandstone wastewater, fast settling speed, high production efficiency and good mechanical properties of the brick made of the treated pressure filtration soil, and low content of flocculants and a small amount of water reducing agent in the sand washing water treated by the precipitation agent, so that the recycled washed machine-made sand and gravel can be directly used in a concrete mixing station, the dosage of the additive is reduced, the cost is saved, and the quality of the concrete is not adversely affected.

[0007] The technical scheme for solving the above technical problems is as follows:

[0008] The precipitation agent for pressure filtration soil comprises component I and component II, the total weight of component I is 100 parts, and the component I comprises the following raw materials in the following weight parts: 20-30 parts of water reducing agent, 0.005-0.01 parts of flocculant, 5-8 parts of organic silicon hydrophobic agent, 5-8 parts of air entraining agent, 3-5 parts of emulsifier, 1-2 parts of suspension dispersing agent, and the rest is water, and the component II is quicklime.

[0009] According to the above scheme, the flocculant is anionic polyacrylamide, preferably, the molecular weight of the anionic polyacrylamide is 8-12 million, and the ionic degree is 10%-20%.

[0010] According to the above scheme, the organic silicon hydrophobic agent is one or more of n-octadecyl triethoxysilane, n-hexadecyl trimethoxysilane and dodecyl methyl dimethoxysilane.

[0011] According to the above scheme, the air entraining agent is one or more of sodium dodecyl benzene sulfonate, sodium dodecyl sulfonate and sodium dodecyl sulfate.

[0012] According to the above scheme, the emulsifier is one or more of fatty alcohol ether phosphate and fatty alcohol polyoxyethylene ether sodium sulfate.

[0013] According to the above scheme, the suspension dispersing agent is one or more of water-based polyamide wax and alkyl phenol ether sulfosuccinic acid ester sodium.

[0014] According to the above scheme, the preparation method of component I is that the raw materials in component I are mixed and stirred at room temperature for 1-3 hours.

[0015] According to the above scheme, the water reducing agent comprises the following raw materials by mass fraction: 5-10 parts of monounsaturated carboxylic acid, 5-10 parts of diunsaturated carboxylic acid or anhydride, 1-2 parts of anionic functional monomer, 0.5-1.5 parts of benzene ring monomer, 0.01-0.02 parts of crosslinking monomer, 0.4-0.8 parts of chain transfer agent, 0.4-0.8 parts of oxidizing agent, 0.02-0.05 parts of reducing agent, and the rest is water. The solid content of the prepared water reducing agent is 20%-25%.

[0016] According to the above scheme, the molecular weight of the water reducing agent is 200,000-500,000, and the PDI is 1.2-1.6.

[0017] According to the above scheme, the monounsaturated carboxylic acid is at least one of acrylic acid and methacrylic acid.

[0018] The diunsaturated carboxylic acid or anhydride is at least one of maleic anhydride, fumaric acid, and itaconic acid.

[0019] The anionic functional monomer is at least one of sodium methacrylsulfonate, 2-acrylamido-2-methyl acrylate sulfonate sodium, sodium allylsulfonate, and 2-hydroxyethyl methacrylate phosphate.

[0020] The benzene ring monomer is at least one of 3-phenyl-2-propenoic acid, p-styrene sulfonic acid sodium, p-hydroxystyrene, and 4-vinylbenzoic acid.

[0021] The crosslinking monomer is at least one of ethoxylated trimethylolpropane triacrylate, glycerol trihydroxypropyl ether triacrylate, and tris(2-hydroxyethyl) isocyanuric acid triacrylate.

[0022] The oxidizing agent is at least one of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, and benzoyl peroxide.

[0023] The chain transfer agent is at least one of mercaptoacetic acid, mercaptoethanol, mercaptopropionic acid, and sodium hypophosphite.

[0024] The reducing agent is at least one of ascorbic acid, ferrous sulfate, and sodium formaldehyde sulfoxylate.

[0025] Preferably, the hydrogen peroxide is industrial-grade hydrogen peroxide with a concentration of 27.5%.

[0026] According to the above scheme, the preparation method of the water reducing agent is as follows:

[0027] S1. Prepare a base material with a concentration of 30% by adding water to the diunsaturated carboxylic acid or anhydride, anionic functional monomer, and benzene ring monomer, and stir and dissolve at a temperature of 45-70°C, then add the oxidizing agent and stir evenly.

[0028] S2. A monobasic unsaturated carboxylic acid is formulated into a solution A with a concentration of 40% to 50%, a chain transfer agent is formulated into a mixed solution B with a concentration of 5% together with a reducing agent, a crosslinking monomer is formulated into a solution C with a concentration of 0.1%, the solutions A, B and C are added drop by drop into the base material within 3 to 3.5 hours to react, after the reaction is completed, the temperature is kept for 1 hour, and the remaining water is added to obtain the water reducing agent.

[0029] The use method of the pressure filtration soil water reducing agent is as follows: the sand and stone aggregate washing mud is introduced into sewage and a pool, is stirred to achieve a homogeneous effect by a stirrer, is lifted to a sludge rapid settling tank by a lifting pump, component I of the pressure filtration soil water reducing agent is added by a vibrating type dosing device, a stirring machine is started to stir for 1 to 2 minutes, is kept for 30 to 60 minutes, the upper water overflows to a clean water storage and recycling pool for recycling, component II of the pressure filtration soil water reducing agent is added to the lower mud, and the mud is stirred at intervals, and then is sent to a plate and frame filter press by a screw pump to perform solid-liquid terminal separation by high-pressure diaphragm filtration.

[0030] Preferably, the mud is stirred for 1 minute every 20 minutes after the addition of component II, and is sent to the plate and frame filter press by the screw pump after the reaction for 2 hours.

[0031] According to the above scheme, the addition amounts of component I and component II are 1% to 2% respectively.

[0032] The pressure filtration soil water reducing agent of the application has the following beneficial effects:

[0033] After the pressure filtration soil water reducing agent of the application is added to the aggregate washing mud, complete flocculation and loose sedimentation are achieved, the filtration speed is fast when the deposited sludge is subjected to solid-liquid separation in a common plate and frame filter press, the water content of the pressure filtration soil can be reduced to below 15%, the volume and amount are reduced, and transportation and subsequent disposal and utilization are facilitated.

[0034] The conventional flocculants have high molecular weight and large addition amount, and when the recycled water treated by the flocculants is recycled, a certain amount of flocculant is left on the surface of the machine-made sand and stone, the cohesiveness of the concrete is increased, the dispersing performance is poor, the fluidity is low, the setting time is accelerated, the concrete is difficult to be constructed, and the mechanical properties are also reduced to a certain extent. The recycled water treated by the pressure filtration soil water reducing agent of the application contains less flocculant and a certain amount of linear polycarboxylic acid water reducing agent, and the machine-made sand washed by the recycled water can be directly used in a concrete mixing station, so that the addition amount of the admixture is reduced and the cost is saved.

[0035] The pressure filtration soil water reducing agent of the application is different from the conventional sludge dewatering treatment agent, has simple preparation method, small amount, simple use method, does not change the daily operation process of the user, has strong adaptability in the sand and stone wastewater, can improve the washing sand dewatering, volume and amount reduction, and disposal and utilization of the machine-made sand, can save raw material resources and human resources, and save the cost.

[0036] The water content of the filter press soil treated by the water reducing agent for filter press soil is low, the plasticity is relatively low, the stirring efficiency is high when preparing the tailing brick, the materials are uniform, the equipment is not easy to adhere, and the production efficiency is high; the tailing brick prepared has low water material ratio, is uniform and compact, contains no soil mass, and has good mechanical properties. And due to the low water content, more filter press soil can be mixed in when preparing the brick, and the waste resources are further utilized and the cost is saved. DETAILED DESCRIPTION

[0037] The principles and features of the present application are described below in conjunction with specific embodiments, and the examples are used to explain the present application and not to limit the scope of the present application.

[0038] It should be noted that in the description of the embodiments of the present application, the description of the term "some specific embodiments" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the illustrative description of the above-mentioned terms does not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0039] The present application provides a water reducing agent for filter press soil, which comprises component I and component II, the total weight of component I is 100 parts, and the raw materials include the following weight parts: water reducing agent 20-30 parts, flocculating agent 0.005-0.01 parts, organic silicon hydrophobic agent 5-8 parts, air entraining agent 5-8 parts, emulsifier 3-5 parts, and suspension dispersing agent 1-2 parts, and the balance is water, and component II is quicklime.

[0040] In some specific embodiments, the flocculating agent is anionic polyacrylamide, preferably, the molecular weight of the anionic polyacrylamide is 8-12 million, and the ionic degree is 10%-20%.

[0041] In some specific embodiments, the organic silicon hydrophobic agent is one or more of n-octadecyl triethoxysilane, n-hexadecyl trimethoxysilane, and dodecyl methyl dimethoxysilane.

[0042] In some specific embodiments, the air entraining agent is one or more of sodium dodecyl benzene sulfonate, sodium dodecyl sulfonate, and sodium dodecyl sulfate.

[0043] In some specific embodiments, the emulsifier is one or more of fatty alcohol ether phosphate, and fatty alcohol polyoxyethylene ether sodium sulfate.

[0044] In some specific embodiments, the suspension dispersing agent is one or more of water-based polyamide wax, and alkyl phenol ether sulfosuccinic acid sodium.

[0045] The preparation method of the component I is as follows: the raw materials in the component I are mixed and stirred at normal temperature for 1-3 hours.

[0046] In some embodiments, the water reducing agent comprises the following raw materials by mass fraction: 5-10 parts of monounsaturated carboxylic acid, 5-10 parts of diunsaturated carboxylic acid or anhydride, 1-2 parts of anionic functional monomer, 0.5-1.5 parts of benzene ring monomer, 0.01-0.02 parts of crosslinking monomer, 0.4-0.8 parts of chain transfer agent, 0.4-0.8 parts of oxidizing agent, 0.02-0.05 parts of reducing agent, and the rest is water, with a solid content of 20%-25%.

[0047] In some embodiments, the molecular weight of the water reducing agent is 200,000-500,000, and the PDI is 1.2-1.6.

[0048] In some embodiments, the monounsaturated carboxylic acid is at least one of acrylic acid and methacrylic acid;

[0049] The diunsaturated carboxylic acid or anhydride is at least one of maleic anhydride, fumaric acid and itaconic acid;

[0050] The anionic functional monomer is at least one of sodium methacrylsulfonate, 2-acrylamido-2-methyl acrylate sulfonate sodium, sodium allylsulfonate and 2-hydroxyethyl methacrylate phosphate;

[0051] The benzene ring monomer is at least one of 3-phenyl-2-propenoic acid, p-styrenesulfonic acid sodium, p-hydroxystyrene and 4-vinylbenzoic acid;

[0052] The crosslinking monomer is at least one of ethoxylated trimethylolpropane triacrylate, glycerol trihydroxypropyl ether triacrylate and tris(2-hydroxyethyl) isocyanuric acid triacrylate;

[0053] The oxidizing agent is at least one of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate and benzoyl peroxide;

[0054] The chain transfer agent is at least one of mercaptoacetic acid, mercaptoethanol, mercaptopropionic acid and sodium hypophosphite;

[0055] The reducing agent is at least one of ascorbic acid, ferrous sulfate and sodium formaldehyde sulfoxylate.

[0056] In some embodiments, the hydrogen peroxide is industrial-grade hydrogen peroxide with a concentration of 27.5%.

[0057] The preparation method of the water reducing agent is as follows:

[0058] S1. The binary unsaturated carboxylic acid or anhydride, anionic functional monomer and benzene ring monomer are prepared into a base material with a concentration of 30%, heated to 45-70 DEG C and stirred to dissolve, then an oxidizing agent is added and stirred evenly;

[0059] S2. The monovalent unsaturated carboxylic acid is prepared into a solution A with a concentration of 40%-50%, the chain transfer agent and reducing agent are prepared into a mixed solution B with a concentration of 5%, and the crosslinking monomer is prepared into a solution C with a concentration of 0.1%, then the A solution, B solution and C solution are added dropwise into the base material within 3-3.5 hours, after the reaction, the mixture is kept for 1 hour, then the remaining water is added to obtain the water reducing agent.

[0060] The use method of the water reducing agent for filter soil is as follows: the sand and stone aggregate washing mud is introduced into a sewage neutralization tank, stirred by a stirrer to achieve a homogeneous effect, then lifted to a sludge rapid settling tank by a lifting pump, component I of the water reducing agent for filter soil is added through a vibration type dosing device, a stirring machine is started to stir for 1-2 minutes, kept for 30-60 minutes, the upper water overflows to a clean water storage and recycling tank, and all is used for clean production, component II of the water reducing agent for filter soil is added to the lower mud, then stirred at intervals, and then sent to a plate and frame filter press through a screw pump to perform solid-liquid terminal separation through high-pressure diaphragm filtration.

[0061] In some specific embodiments, the stirring is performed every 20 minutes for 1 minute after the addition of component II, and the reaction is performed for 2 hours, then the mixture is sent to the plate and frame filter press through the screw pump.

[0062] According to the above scheme, the addition amounts of component I and component II are 1%-2% respectively.

[0063] In the water reducing agent for filter soil, the flocculating agent utilizes a high molecular chain network to capture the fine particles suspended in water through adsorption and electrostatic neutralization, performs bridging between the particles, and forms small flocs, when the small flocs reach a certain degree of coagulation to form large flocs, the large flocs are precipitated under the action of gravity. 3+ The main minerals in the aggregate washing mud include limestone, dolomite and quartz, and the main components of the soil include illite and chlorite. 4+ Therefore, the negatively charged anionic polyacrylamide can better play an electrostatic neutralization effect in the aggregate washing mud, compress the double electric layer, and reduce the electric potential to make the small particles lose stability and settle.

[0064] The water reducing agent connects linear polycarboxylic acid molecules together by cross-linking monomers to form a dense network of polymer chains, which can cooperate with the coagulation and bridging of the flocculating agent. The main chain contains monobasic carboxylic acid and dibasic carboxylic acid, and the anion density is higher. The main chain contains strong anion groups such as phosphoric acid groups and sulfonic acid groups, and the electrostatic interaction with the particles is stronger, which can fully play the adsorption bridging, net trapping and sweeping effect of the flocculating agent. In addition, the rigid benzene ring structure is introduced into the main chain of the water reducing agent as a microskeleton to reduce the degree of curling of the molecular chain, which is beneficial to the formation of small and loose flocs of solid particles in the system. And the water reducing agent does not contain a long side chain of polyoxyethylene, and the molecular weight is large, which increases the steric effect, and does not insert into the structure of clay minerals, but only adsorbs on the surface, reducing unnecessary loss. After the flocs are precipitated and the upper water overflow, lime is added to the lower layer of mud to stir the system to be alkaline. The ester groups in the cross-linking monomer molecules are hydrolyzed and broken under alkaline conditions, and most of the polycarboxylic acid molecules become straight chain structures. The active groups in the molecular structure of the carboxyl group form an adsorption layer with a certain amount of charge at the solid-liquid interface through wetting, adsorption, ion migration, etc. The agglomeration structure of clay mineral particles is destroyed by lubrication, electrostatic repulsion, etc. to release free water, which is beneficial to the discharge of water during the later pressure filtration. The water reducing agent used in the present application contains three ester groups in one molecule of cross-linking monomer, and the content of hydrolysis functional groups is high. Therefore, even under extremely high cross-linking conditions, the cross-linked structure can still be effectively opened in an alkaline environment, and a large number of straight-chain water reducing agent molecules can fully play a water reducing role in the later stage.

[0065] The structure of the organic silicon hydrophobic agent is as follows: R'-Si-(OR)3, wherein R' is an alkyl group, OR is a methoxy group, an ethoxy group, an acetoxy group, etc. -Si-OR can be hydrolyzed to obtain -Si-OH with high reactivity. There are also a large amount of SiO2 in the mineral components in the aggregate washing mud, which can be combined with -Si-OH. The non-polar -Si-R at the end of the molecule repels hydrogen atoms in water, reduces the thickness of the water film adsorbed on the surface of the particles, and releases more free water.

[0066] The air entraining agent can significantly improve the air content of the aggregate washing mud during the stirring process, and the air bubbles are distributed in the aggregate washing mud. During mechanical pressure filtration, a large number of small air bubbles squeeze the adsorbed water in the pores of the pressure filtration soil and the interior of the flocs, causing it to be released. When the small air bubbles are successively broken, the air pressure generated by the small air bubbles blows again through the small pores in the pressure filtration soil, further expelling the water inside the pressure filtration soil. In addition, the air bubbles form pore channels, and the water in the mud can be discharged through the channels, significantly reducing the water content of the pressure filtration soil mud cake.

[0067] The emulsifier has good decontamination and cleaning functions, can prevent the filter cloth from being adhered by the filter cake, and prolongs the service life of the filter cloth. The filter channels formed by the filter cloth fibers are easily blocked by the filter cake under the huge pressure during the filter pressing, and the filtrate is difficult or even impossible to be discharged, which greatly increases the moisture content of the filter cake. The preferred emulsifiers have good surface activity and emulsifying performance, so that the liquid can easily wet and penetrate the solid particles and the filter cloth fibers, the adhesion between the filter cake and the filter cloth is reduced, and the filter holes are prevented from being blocked. Meanwhile, the good surface activity of the emulsifiers can effectively reduce the surface tension of the liquid, reduce the solid-liquid interface energy between the solid particles and the liquid phase, and there is more free water in the system. In addition, the emulsifiers also have certain foam stability, which can improve the liquid film strength of the foam and improve the foam stability.

[0068] The suspending agent can ensure that the water-reducing agent for filter pressing soil remains in a uniform and stable liquid state, and does not separate for a long time. The preferred suspending agents in the present application have good emulsifying property, dispersibility, wettability and suspensibility, so that the several components of the water-reducing agent for filter pressing soil are uniformly dispersed after being mixed with water, and are not prone to separation caused by sedimentation.

[0069] In terms of the specifications of the flocculating agent, within a certain range, the higher the anionic degree, the more obvious the "electrical neutralization" effect, but when the anionic degree exceeds the range, there will be residual negative charge, and the particles will be stabilized again due to repulsion between them. Therefore, the anionic polyacrylamide has the best comprehensive effect when the anionic degree is 10%-20%. The size of the molecular chain of the polyacrylamide is also a key factor affecting the coagulation and "bridging" effect. The higher the molecular weight of the flocculating agent, the larger the size of the flocculation formed by the flocculating agent, and when the size of the flocculation is too small, the speed of sedimentation will be affected, and when the size of the flocculation is too large, the flocculation will constrain more water inside, thereby reducing the dryness of the filter cake. The anionic polyacrylamide selected in the present application has a molecular weight of 8 million-12 million, and the size of the flocculation is appropriate and the flocculation formed is relatively stable. The molecular weight of the water-reducing agent with a molecular weight of 200-500 thousand is smaller than that of the polyacrylamide, and the water-reducing agent plays a synergistic role in the coagulation and bridging of the flocculating agent.

[0070] As an inorganic material, the quicklime can provide an alkaline environment to promote the hydrolysis of the reticular polycarboxylic acid molecules into straight chains, and can also be used as a physical conditioner for the water-washing of the slurry, and can have a physical and chemical reaction with the slurry to establish capillary pore channels and form a compact and slightly porous framework structure, thereby improving the compressibility of the slurry, improving the dewatering performance of the sludge, and improving the strength of the filter cake after dewatering as a raw material for brick making.

[0071] The filter pressing soil water-reducing agent has a synergistic relationship among components, and is indispensable. The aggregate washing mud contains a large amount of water, mainly including interstitial water, capillary water, adsorbed water and internal water. In the stirring and flocculation process, the added anionic polyacrylamide and cross-linked water-reducing agent can fully play the roles of charge neutralization, adsorption bridging, double electric layer compression, net capture and sweeping, and can form small flocs and large flocs. The added organic silicon hydrophobic agent can reduce the thickness of the adsorbed water film on the particle surface. These components make the formed flocs loose, and more free water in the system can be pressed out. After the floc precipitation and overflow of the upper water, the added quicklime provides an alkaline environment to promote the hydrolysis of the cross-linked water-reducing agent into a linear shape, the linear water-reducing agent destroys the agglomeration structure of the clay mineral particles, and releases more free water. In the process of sludge after filter pressing deposition, the air entraining agent extrudes pore water, the emulsifier improves the liquid film strength of the foam, the bubble string increases the channel for mud water to be discharged, and the bubble breaks again when it breaks; the emulsifier prevents the filter cloth from being blocked; the air entraining agent and the emulsifier can reduce the surface tension of the liquid, so that the bound water on the surface of the solid particles is reduced; and the quicklime improves the compressibility of the mud. These can greatly reduce the moisture content of the filter pressing mud cake. The suspending agent ensures the stability of the system, so that the system does not separate for a long time. The components cooperate with each other, jointly act, and have a synergistic effect, so that a good water-reducing effect is achieved.

[0072] On the basis of the above-mentioned embodiments, the present application gives the following specific examples to further illustrate the present application. It should be understood that these examples are only used to illustrate the present application and are not used to limit the scope of the present application. The experimental methods not specified in the following examples are generally carried out according to the conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are calculated by mass.

[0073] Example 1

[0074] The present embodiment provides a filter pressing soil water-reducing agent, which comprises component I and component II, wherein component I comprises the following raw materials by weight: water-reducing agent 20 parts, anionic polyacrylamide 0.005 parts, n-octadecyl triethoxysilane 5 parts, sodium dodecyl benzene sulfonate 5 parts, fatty alcohol ether phosphate 3 parts, water-based polyamide wax 1 part, and water 65.995 parts, and component II is quicklime.

[0075] The preparation method of component I is to dissolve different raw material components, and stir for 1 hour at room temperature.

[0076] The molecular weight of the anionic polyacrylamide is 8 million, and the ionic degree is 10%.

[0077] The water reducing agent comprises the following components by weight: acrylic acid 5 parts, fumaric acid 5 parts, sodium methacryl sulfonate 1 part, 3-phenyl-2-propenoic acid 0.5 part, ethoxylated trimethylolpropane triacrylate 0.01 part, mercaptoacetic acid 0.4 part, 27.5% hydrogen peroxide 0.4 part, ascorbic acid 0.02 part, and the rest is water, and the solid content of the prepared water reducing agent is adjusted to 20%.

[0078] The preparation method of the water reducing agent is as follows:

[0079] (1) The fumaric acid, sodium methacryl sulfonate and 3-phenyl-2-propenoic acid are added to a four-necked flask, water is added to prepare a base material with a concentration of about 30%, the base material is heated to 45°C and stirred to dissolve, 27.5% hydrogen peroxide is added to the flask at one time after 30 minutes.

[0080] (2) After stirring for 5 minutes in step (1), acrylic acid is prepared into a solution A with a concentration of 40%; mercaptoacetic acid and ascorbic acid are prepared into a mixed solution B with a concentration of 5%; ethoxylated trimethylolpropane triacrylate is prepared into a solution C with a concentration of 0.1%; the A solution, the B solution and the C solution are gradually added to the flask for reaction within 3 hours by using a peristaltic pump.

[0081] (3) After the reaction in step (2) is completed, the temperature is kept for 1 hour.

[0082] (4) After step (3), a proper amount of water is added to the four-necked flask at one time to prepare a water reducing agent for soil pressing and filtering with a solid content of 20%.

[0083] Example 2

[0084] The present embodiment provides a water reducing agent for soil pressing and filtering, which comprises component I and component II, wherein component I comprises the following raw materials by weight: water reducing agent 30 parts, anionic polyacrylamide 0.01 part, n-hexadecyl trimethoxysilane 8 parts, sodium dodecyl sulfonate 8 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, alkylphenol ether sulfosuccinate sodium 2 parts, and water 46.99 parts; component II: quicklime.

[0085] The preparation method of component I is to dissolve different raw material components and stir for 3 hours at room temperature.

[0086] The anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 20%.

[0087] The water reducing agent comprises the following components by weight: methyl acrylate 10 parts, maleic anhydride 10 parts, 2-acrylamido-2-methyl methacryl sulfonate sodium 2 parts, p-toluene sulfonate sodium 1.5 parts, glycerol trihydroxypropyl ether triacrylate 0.02 part, mercaptoethanol 0.8 part, ammonium persulfate 0.8 part, ferrous sulfate 0.05 part, and the rest is water.

[0088] The preparation method of the water reducing agent is:

[0089] (1) Maleic anhydride, 2-acrylamido-2-methyl methacrylate sodium, and p-styrene sulfonic acid sodium are added to a four-necked flask, and water is added to prepare a stock solution with a concentration of about 30%, the stock solution is heated to 70°C and stirred to dissolve, after 30 min, ammonium persulfate is added to the flask at once.

[0090] (2) After stirring for 5 min in step (1), methacrylic acid is prepared into a solution A with a concentration of 40%; mercaptoethanol and ferrous sulfate are prepared into a mixed solution B with a concentration of 5%; glycerol trihydroxypropyl ether triacrylate is prepared into a mixed solution C with a concentration of 0.1%; A, B, and C are gradually added to the flask using a peristaltic pump within 3.5 h to react.

[0091] (3) After the reaction in step (2) is completed, the temperature is kept for 1 h.

[0092] (4) After step (3), an appropriate amount of water is added to the four-necked flask to prepare a water reducing agent for soil pressing with a solid content of 20%.

[0093] Example 3

[0094] The present embodiment provides a water reducing agent for soil pressing, which comprises component I and component II, wherein component I comprises the following raw materials by weight: water reducing agent 25 parts, anionic polyacrylamide 0.0075 parts, dodecylmethyl dimethoxy silane 6.5 parts, sodium dodecyl sulfate 6.5 parts, fatty alcohol ether phosphate 4 parts, water-based polyamide wax 1.5 parts, and water 56.4925 parts; component II: quicklime.

[0095] The preparation method of component I is to dissolve different raw material components, and stir for 3 hours at room temperature.

[0096] The anionic polyacrylamide has a molecular weight of 10 million and an ionic degree of 15%.

[0097] The water reducing agent comprises the following components by weight: acrylic acid 7.5 parts, itaconic acid 7.5 parts, sodium allyl sulfonate 1.5 parts, p-hydroxystyrene 1 part, tris(2-hydroxyethyl) isocyanuric acid triacrylate 0.015 parts, mercaptopropionic acid 0.6 parts, potassium persulfate 0.6 parts, and sodium formaldehyde sulfoxylate 0.035 parts, and the rest is water.

[0098] The preparation method of the water reducing agent is:

[0099] (1) Itaconic acid, allyl sulfonate sodium, and p-hydroxystyrene are added to a four-necked flask, and water is added to prepare a stock solution with a concentration of about 30%, the stock solution is heated to 60°C and stirred to dissolve for 30 min, and then potassium persulfate is added to the flask at once.

[0100] (2) After stirring for 5 minutes in step (1), prepare a solution A of acrylic acid with a concentration of 40%; prepare a mixed solution B of mercaptopropionic acid and sodium formaldehyde sulfoxylate with a concentration of 5%; prepare a mixed solution C of tris (2-hydroxyethyl) isocyanuric acid triacrylate with a concentration of 0.1%; and add A, B and C into the flask by using a peristaltic pump for reaction within 3 hours.

[0101] (3) After the reaction in step (2) is completed, keep the temperature for 1 hour.

[0102] (4) After step (3), add an appropriate amount of water into the four-necked flask to prepare a water-reducing agent for filter press soil with a solid content of 20%.

[0103] Example 4

[0104] The present example provides a water-reducing agent for filter press soil, which comprises component I and component II, wherein component I comprises the following raw materials in parts by weight: water-reducing agent 22 parts, anionic polyacrylamide 0.01 part, n-octadecyl triethoxysilane 4 parts, n-hexadecyl trimethoxysilane 4 parts, sodium dodecylbenzenesulfonate 3 parts, sodium dodecylsulfonate 3 parts, fatty alcohol ether phosphate 3 parts, sodium alkylphenol ether sulfosuccinate 2 parts, and water 58.99 parts; and component II: quicklime.

[0105] The preparation method of component I is to dissolve different raw material components and stir for 3 hours at room temperature.

[0106] The 0.005 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 15%, and the 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 15%.

[0107] The water-reducing agent comprises the following components in parts by weight: acrylic acid 4 parts, methacrylic acid 4 parts, fumaric acid 6 parts, methacrylic acid-2-hydroxyethyl ester phosphate 1.5 parts, 4-vinylbenzoic acid 1 part, ethoxylated trimethylolpropane triacrylate 0.015 parts, sodium hypophosphite 0.8 parts, sodium persulfate 0.6 parts, ascorbic acid 0.04 parts, and the rest is water.

[0108] The preparation method of the water-reducing agent is as follows:

[0109] (1) Add fumaric acid, methacrylic acid-2-hydroxyethyl ester phosphate and 4-vinylbenzoic acid into a four-necked flask, add water to prepare a base material with a concentration of about 30%, heat the base material to 60°C and stir to dissolve, and after 30 minutes, add sodium persulfate into the flask at one time.

[0110] (2) After stirring for 5 minutes in step (1), prepare a 50% solution A of acrylic acid and methacrylic acid; prepare a 5% mixed solution B of sodium hypophosphite and ascorbic acid; prepare a 0.1% mixed solution C of ethoxylated trimethylolpropane triacrylate; and add A, B and C into the flask by using a peristaltic pump for reaction within 3 hours.

[0111] (3) After the reaction in step (2) is completed, keep the temperature for 1 hour.

[0112] (4) After step (3), add an appropriate amount of water into the four-necked flask to prepare a 20% water-reducing agent for filter press soil.

[0113] Example 5

[0114] The present example provides a water-reducing agent for filter press soil, which comprises component I and component II, wherein component I comprises the following raw materials in parts by weight: water-reducing agent 26 parts, anionic polyacrylamide 0.0075 parts, n-octadecyl triethoxysilane 6 parts, sodium dodecyl benzene sulfonate 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, water-based polyamide wax 1 part, and water 54.9925 parts; and component II: quicklime.

[0115] The 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%, and the 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0116] The preparation method of component I is to dissolve different raw material components and stir for 1 hour at room temperature.

[0117] The water-reducing agent comprises the following components in parts by weight: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methyl acrylate sulfonic acid sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropanoic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0118] The preparation method of the water-reducing agent is as follows:

[0119] (1) Add maleic anhydride, 2-acrylamido-2-methyl acrylate sulfonic acid sodium and p-hydroxystyrene into a four-necked flask, add water to prepare a base material with a concentration of about 30%, heat the base material to 50°C and stir to dissolve, and after 30 minutes, add 27.5% hydrogen peroxide into the flask at one time.

[0120] (2) After stirring for 5 minutes in step (1), acrylic acid is prepared into a solution A with a concentration of 40%; mercaptopropionic acid and ascorbic acid are prepared into a mixed solution B with a concentration of 5%; glycerol trihydroxypropyl ether triacrylate is prepared into a mixed solution C with a concentration of 0.1%; and the A solution, the B solution and the C solution are gradually added into the flask by using a peristaltic pump within 3 hours to perform the reaction.

[0121] (3) After the reaction in step (2) is completed, the mixture is kept for 1 hour.

[0122] (4) After step (3), a proper amount of water is added into the four-necked flask to prepare a water-reducing agent for filter cake with a solid content of 20%.

[0123] Comparative Example 1

[0124] Compared with the examples, the water-reducing agent for filter cake provided in the comparative example does not include a water-reducing agent. The water-reducing agent for filter cake provided in the comparative example includes component I and component II, wherein component I includes the following raw materials in parts by weight: anionic polyacrylamide 0.0075 parts, n-octadecyl triethoxysilane 6 parts, sodium dodecyl benzene sulfonate 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, water-based polyamide wax 1 part, and water 80.9925 parts; and component II is quicklime.

[0125] Among them, 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%; and 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0126] The preparation method of component I of the above water-reducing agent for filter cake is to dissolve different components and stir for 1 hour at room temperature.

[0127] Comparative Example 2

[0128] Compared with the examples, the water-reducing agent for filter cake provided in the comparative example does not include a flocculating agent. The water-reducing agent for filter cake provided in the comparative example includes component I and component II, wherein component I includes the following raw materials in parts by weight: water-reducing agent 26 parts, n-octadecyl triethoxysilane 6 parts, sodium dodecyl benzene sulfonate 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, water-based polyamide wax 1 part, and water 55 parts; and component II is quicklime.

[0129] The preparation method of component I is to dissolve different raw materials and stir for 1 hour at room temperature.

[0130] Among them, the water-reducing agent includes the following components in parts by weight: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methylpropyl sulfonic acid sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropionic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0131] The preparation method of the water reducing agent is as follows:

[0132] (1) Maleic anhydride, 2-acrylamido-2-methyl methacrylate sodium, and p-hydroxystyrene are added into a four-necked flask, and water is added to prepare a stock solution with a concentration of about 30%. The stock solution is heated to 50°C and stirred to dissolve. After 30 minutes, 27.5% hydrogen peroxide is added into the flask at one time.

[0133] (2) After stirring for 5 minutes in step (1), acrylic acid is prepared into a solution A with a concentration of 40%; mercaptopropionic acid and ascorbic acid are prepared into a mixed solution B with a concentration of 5%; and glycerol trihydroxypropyl ether triacrylate is prepared into a mixed solution C with a concentration of 0.1%. The solutions A, B, and C are gradually added into the flask using a peristaltic pump within 3 hours to carry out the reaction.

[0134] (3) After the reaction in step (2) is completed, the temperature is kept for 1 hour.

[0135] (4) After step (3), an appropriate amount of water is added into the four-necked flask to prepare a water reducing agent for filter pressing soil with a solid content of 20%.

[0136] Comparative Example 3

[0137] Compared with the examples, the water reducing agent for filter pressing soil provided by the comparative example does not include an organic silicon hydrophobic agent. The water reducing agent for filter pressing soil provided by the comparative example includes component I and component II. Component I includes the following raw materials by weight: water reducing agent 26 parts, anionic polyacrylamide 0.0075 parts, sodium dodecyl benzene sulfonate 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, water-based polyamide wax 1 part, and water 60.9925 parts. Component II is quicklime.

[0138] The preparation method of component I is to dissolve different raw materials and stir for 1 hour at room temperature.

[0139] Among them, 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%; and 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0140] The water reducing agent includes the following components by weight: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methyl methacrylate sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropionic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0141] The preparation method of the water reducing agent is as follows:

[0142] (1) Maleic anhydride, 2-acrylamido-2-methylpropane sulfonic acid sodium, p-hydroxystyrene were added into a four-necked flask, and water was added to prepare a base material with a concentration of about 30%. The base material was heated to 50°C and stirred to dissolve. After 30 minutes, 27.5% hydrogen peroxide was added into the flask at one time.

[0143] (2) After stirring for 5 minutes in step (1), acrylic acid was prepared into a solution A with a concentration of 40%; mercaptopropionic acid and ascorbic acid were prepared into a mixed solution B with a concentration of 5%; glycerol trihydroxypropyl ether triacrylate was prepared into a mixed solution C with a concentration of 0.1%. A, B and C were gradually added into the flask using a peristaltic pump within 3 hours to carry out the reaction.

[0144] (3) After the reaction in step (2) was completed, the temperature was kept for 1 hour.

[0145] (4) After step (3), an appropriate amount of water was added into the four-necked flask to prepare a water-reducing agent for filter soil with a solid content of 20%.

[0146] Comparative Example 4

[0147] Compared with the examples, the water-reducing agent for filter soil provided by the comparative example does not include an air entraining agent. The water-reducing agent for filter soil provided by the comparative example includes component I and component II. Component I includes the following raw materials by weight: water-reducing agent 26 parts, anionic polyacrylamide 0.0075 parts, n-octadecyl triethoxysilane 6 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, water-based polyamide wax 1 part, and water 61.9925 parts. Component II is quicklime.

[0148] The preparation method of component I is to dissolve different raw materials and stir for 1 hour at room temperature.

[0149] The 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%, and the 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0150] The water-reducing agent includes the following components by weight: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methylpropane sulfonic acid sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropionic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0151] The preparation method of the water-reducing agent is as follows:

[0152] (1) Maleic anhydride, 2-acrylamido-2-methyl acrylate sodium, p-hydroxystyrene were added to a four-necked flask, and water was added to prepare a base material with a concentration of about 30%. The base material was heated to 50°C and stirred to dissolve. After 30 minutes, 27.5% hydrogen peroxide was added to the flask at once.

[0153] (2) After stirring for 5 minutes in step (1), acrylic acid was prepared into a solution A with a concentration of 40%; mercaptopropionic acid and ascorbic acid were prepared into a mixed solution B with a concentration of 5%; and glycerol trihydroxypropyl ether triacrylate was prepared into a mixed solution C with a concentration of 0.1%. A, B, and C were gradually added to the flask using a peristaltic pump within 3 hours to carry out the reaction.

[0154] (3) After the reaction in step (2) was completed, the temperature was kept for 1 hour.

[0155] (4) After step (3), an appropriate amount of water was added to the four-necked flask to prepare a water-reducing agent for filter cake with a solid content of 20%.

[0156] Comparative Example 5

[0157] Compared with the examples, the water-reducing agent for filter cake provided by the comparative example does not include an emulsifier. The water-reducing agent for filter cake provided by the comparative example includes component I and component II. Component I includes the following raw materials by weight: water-reducing agent 26 parts, anionic polyacrylamide 0.0075 parts, n-octadecyl triethoxysilane 6 parts, sodium dodecyl benzene sulfonate 7 parts, water-based polyamide wax 1 part, and water 59.9925 parts. Component II is quicklime.

[0158] The preparation method of component I is to dissolve different raw materials and stir for 1 hour at room temperature.

[0159] Among them, 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%; 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0160] The water-reducing agent includes the following components by weight: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methyl acrylate sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropionic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0161] The preparation method of the water-reducing agent is as follows:

[0162] (1) Maleic anhydride, 2-acrylamido-2-methyl acrylate sodium, p-hydroxystyrene were added to a four-necked flask, and water was added to prepare a base material with a concentration of about 30%. The base material was heated to 50°C and stirred to dissolve. After 30 minutes, 27.5% hydrogen peroxide was added to the flask at once.

[0163] (2) After stirring for 5 minutes in step (1), acrylic acid is prepared into a solution A with a concentration of 40%; mercaptopropionic acid and ascorbic acid are prepared into a mixed solution B with a concentration of 5%; glycerol trihydroxypropyl ether triacrylate is prepared into a mixed solution C with a concentration of 0.1%; and A, B and C are gradually added into the flask by using a peristaltic pump within 3 hours to carry out the reaction.

[0164] (3) After the reaction in step (2) is completed, the temperature is kept for 1 hour.

[0165] (4) After step (3), a proper amount of water is added into the four-necked flask to prepare a water-reducing agent for filter soil with a solid content of 20%.

[0166] Comparative Example 6

[0167] Compared with the examples, the water-reducing agent for filter soil provided in the comparative example does not include a suspension dispersant, and the water-reducing agent for filter soil provided in the comparative example includes component I and component II, wherein component I includes the following raw materials by weight: water-reducing agent 26 parts, anionic polyacrylamide 0.0075 parts, n-octadecyl triethoxysilane 6 parts, sodium dodecyl benzene sulfonate 7 parts, sodium fatty alcohol polyoxyethylene ether sulfate 5 parts, and water 55.9925 parts; and component II: quicklime.

[0168] The preparation method of component I is to dissolve different raw materials and stir for 1 hour at room temperature.

[0169] Among them, 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%, and 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0170] The water-reducing agent includes the following components by mass: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methyl acrylate sulfonic acid sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropionic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0171] The preparation method of the water-reducing agent is as follows:

[0172] (1) Maleic anhydride, 2-acrylamido-2-methyl acrylate sulfonic acid sodium and p-hydroxystyrene are added into a four-necked flask, water is added to prepare a base material with a concentration of about 30%, the base material is heated to 50°C and stirred to dissolve, 27.5% hydrogen peroxide is added into the flask at one time after 30 minutes.

[0173] (2) After stirring for 5 minutes in step (1), acrylic acid is prepared into a solution A with a concentration of 40%; mercaptopropionic acid and ascorbic acid are prepared into a mixed solution B with a concentration of 5%; glycerol trihydroxypropyl ether triacrylate is prepared into a mixed solution C with a concentration of 0.1%; and A, B and C are gradually added into the flask by using a peristaltic pump within 3 hours to perform the reaction.

[0174] (3) After the reaction in step (2) is completed, the solution is kept warm for 1 hour.

[0175] (4) After step (3), a proper amount of water is added into the four-necked flask to prepare a water-reducing agent for filter soil with a solid content of 20%.

[0176] Comparative Example 7

[0177] Compared with the examples, the water-reducing agent for filter soil provided in the comparative example does not include component II. The water-reducing agent for filter soil provided in the comparative example includes the following raw materials by weight: water-reducing agent 26 parts, anionic polyacrylamide 0.0075 parts, n-octadecyl triethoxysilane 6 parts, sodium dodecyl benzene sulfonate 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate 5 parts, water-based polyamide wax 1 part, and water 54.9925 parts.

[0178] The preparation method of the water-reducing agent for filter soil is to dissolve different raw materials and stir for 1 hour at room temperature.

[0179] The 0.0025 parts of anionic polyacrylamide has a molecular weight of 8 million and an ionic degree of 20%, and the 0.005 parts of anionic polyacrylamide has a molecular weight of 12 million and an ionic degree of 10%.

[0180] The water-reducing agent includes the following components by weight: acrylic acid 8 parts, maleic anhydride 5 parts, 2-acrylamido-2-methyl acrylate sulfonic acid sodium 1.5 parts, p-hydroxystyrene 0.5 parts, glycerol trihydroxypropyl ether triacrylate 0.015 parts, mercaptopropionic acid 0.7 parts, 27.5% hydrogen peroxide 0.7 parts, ascorbic acid 0.04 parts, and the rest is water.

[0181] The preparation method of the water-reducing agent is as follows:

[0182] (1) Maleic anhydride, 2-acrylamido-2-methyl acrylate sulfonic acid sodium and p-hydroxystyrene are added into a four-necked flask, water is added to prepare a base material with a concentration of about 30%, the base material is heated to 50°C and stirred to dissolve, 27.5% hydrogen peroxide is added into the flask at one time after 30 minutes.

[0183] (2) After stirring for 5 minutes in step (1), prepare a solution A of acrylic acid with a concentration of 40%; prepare a mixed solution B of mercaptopropionic acid and ascorbic acid with a concentration of 5%; and prepare a mixed solution C of glycerol trihydroxypropyl ether triacrylate with a concentration of 0.1%. Add A, B and C into the flask dropwise using a peristaltic pump within 3 hours to perform the reaction.

[0184] (3) After the reaction in step (2) is completed, keep the temperature constant for 1 hour.

[0185] (4) After step (3), add an appropriate amount of water into the four-necked flask to prepare a water-reducing agent for filter soil with a solid content of 20%.

[0186] Application method

[0187] The application method of the water-reducing agent for filter soil prepared in Examples 1-5 and Comparative Examples 1-7 is as follows: the aggregate washing slurry is put into a sewage neutralization tank and stirred to achieve homogeneity by a stirrer, then lifted to a sludge rapid settling tank by a lifting pump, and the water-reducing agent I for filter soil is added through a vibrating dosing device, the stirrer is started to stir for 2 minutes, and then kept still for 30 minutes, the upper layer water is overflowed into a clean water storage tank for recycling, the lower layer slurry is added with the water-reducing agent II for filter soil, and stirred for 1 minute every 20 minutes, and then sent to a plate-and-frame filter press through a screw pump after 2 hours to perform solid-liquid separation by high-pressure diaphragm filtration. In Comparative Example 7, the water-reducing agent II for filter soil is not needed to be added.

[0188] 1. Performance test

[0189] The aggregate washing slurry used is provided by Huaxin Cement Yangxin Aggregate Factory, which is yellowish in appearance, uniform and sticky, has a specific gravity of 1.20-1.46, a mud content of 20%-30%, and a PH value of 6-7. The main mineral composition and the mass percentage are as follows: quartz 14.5%, clinochlore 5.9%, illite 1.6%, muscovite 14.5%, dolomite 9.3%, and calcite 54.2%.

[0190] The specific test method is as follows:

[0191] 1) Take 500 mL of the aggregate washing slurry in a measuring cup, stir for 2 minutes at a certain speed, add the water-reducing agent I for filter soil with a mass of 2% of the slurry, start the stirrer to stir for 2 minutes, keep still for 60 minutes, pour out the supernatant, add the water-reducing agent II for filter soil with the same weight as the water-reducing agent I for filter soil to the lower layer slurry, stir for 1 minute every 20 minutes, and then filter under a pressure of 0.4 MPa for 2 minutes to obtain the filter cake after filtration. Weigh the dried evaporating dish, record it as W1, weigh the filter cake in the evaporating dish, record it as W2, then take it out after drying in a drying oven at 105°C for 12 hours, weigh it after cooling in the drying dish, and record it as W3.

[0192] The filter cake moisture content is calculated according to Formula 1-1:

[0193] W = (W2-W3) / (W2-W1) x 100%

[0194] In the formula:

[0195] W - filter cake moisture content, %;

[0196] W1 - the mass of the evaporating dish after drying, g;

[0197] W2 - the sum of the mass of the evaporating dish and the mass of the filter cake, g;

[0198] W3 - the sum of the mass of the evaporating dish after drying and the mass of the filter cake, g.

[0199] 2) The prepared filter cake is left to stand for 1 month with the precipitation agent I, and the homogeneity stability is observed.

[0200] The results are shown in Table 1.

[0201] Table 1 Filter cake moisture content and homogeneity stability of the filter cake

[0202]

[0203]

[0204] As shown in Table 1, the filter cake moisture content of the filter cake treated with the precipitation agent of Examples 1-5 and 7 is 12.1%-14.4%, which is better than the filter cake moisture content of 18.9%-27.4% of the filter cake treated with the precipitation agent of Comparative Examples 1-5 and 7. After standing for 1 month, the filter cake treated with the precipitation agent of Examples 1-5 and 7 has no obvious stratification, and has good homogeneity stability. The filter cake treated with the precipitation agent of Comparative Example 6 has slight stratification after standing for 1 month, and has slightly poor homogeneity stability.

[0205] Therefore, the precipitation agent for filter cake can significantly reduce the water content of the filter cake, and the filter cake is uniform and stable without stratification.

[0206] 2, The filter cake treated with the precipitation agent of Examples 1-5 and Comparative Examples 1-7 is used to prepare the fired-free filter cake tailings brick, and the specific method is as follows:

[0207] Small pieces of filter cake, undersize material and cement are uniformly stirred according to the proportion, and the mass percentage of each component in the mixture is as follows: filter cake 60%, undersize material 30%, and cement 10%. After being broken, aged, and broken again, the mixture is placed into a brick machine for molding, and finally the green brick is cured in a steam autoclave, and the steam pressure of the steam autoclave is 1.2 MPa, the temperature is 200°C, and the steam pressure time is 8 hours.

[0208] The compressive strength of the tailing bricks prepared above was determined according to GBT 2542-2012 "Method of Testing Walling Bricks", and the results are shown in Table 2.

[0209] Table 2 Compressive strength of the filter-pressed soil tailing bricks

[0210]

[0211]

[0212] From the above data, the compressive strength of the tailing bricks made of the filter-pressed soil treated with the precipitation agent of the present application examples 1-5 is 16.8-17.7 MPa, which is superior to the compressive strength of the filter-pressed soil tailing bricks made of the filter-pressed soil treated with the precipitation agent of the comparative examples 1-5 and 7, which is 12.1-14.6 MPa. The tailing bricks made of the filter-pressed soil treated with the precipitation agent of the present application examples 1-5 meet the MU15 compressive strength grade requirement of JCT 422-2007 "Non-sintered garbage tailing bricks", while the comparative examples 1-5 and 7 do not meet the minimum grade compressive strength requirement of the standard.

[0213] In the prior art, the amount of the flocculating agent added in the process of treating the aggregate washing mud is one ten-thousandth, while the amount of the precipitation agent added in the present application is 1-2%, wherein the content of the flocculating agent is 0.5-2 parts per million of the aggregate washing mud, which is about one hundredth of the amount of the flocculating agent added in the prior art. Therefore, the content of the flocculating agent in the sand washing water is small, and the performance of the machine-made sand will not be adversely affected when the sand washing water is recycled, and the sand washing water can be directly used in the concrete mixing station, thereby saving the cost.

[0214] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A dewatering agent for filter soil, characterized in that, The product comprises component I and component II. Component I, in 100 parts by weight, includes the following raw materials in parts by weight: 20-30 parts water-reducing agent, 0.005-0.01 parts flocculant, 5-8 parts organosilicon water-repellent agent, 5-8 parts air-entraining agent, 3-5 parts emulsifier, 1-2 parts suspending and dispersing agent, with the balance being water. Component II is quicklime. The water-reducing agent comprises the following raw materials in parts by weight: 5-10 parts of monounsaturated carboxylic acid, 5-10 parts of diunsaturated carboxylic acid or acid anhydride, 1-2 parts of anionic functional monomer, 0.5-1.5 parts of benzene ring monomer, 0.01-0.02 parts of crosslinking monomer, 0.4-0.8 parts of chain transfer agent, 0.4-0.8 parts of oxidant, 0.02-0.05 parts of reducing agent, with the remainder being water, and its solid content is 20%-25%. The monounsaturated carboxylic acid is at least one of acrylic acid and methacrylic acid; The diunsaturated carboxylic acid or anhydride is at least one of maleic anhydride, fumaric acid, and itaconic acid. The anionic functional monomer is at least one of sodium methacrylate sulfonate, sodium 2-acrylamido-2-methacrylate sulfonate, sodium allyl sulfonate, and 2-hydroxyethyl methacrylate phosphate. The benzene ring monomer is at least one of 3-phenyl-2-acrylic acid, sodium p-styrene sulfonate, p-hydroxystyrene, and 4-vinylbenzoic acid; The crosslinking monomer is at least one of ethoxylated trimethylolpropane triacrylate, glyceryl trihydroxypropyl ether triacrylate, and tri(2-hydroxyethyl)isocyanurate triacrylate; The oxidant is at least one of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, and benzoyl peroxide. The chain transfer agent is at least one of mercaptoacetic acid, mercaptoethanol, mercaptopropionic acid, and sodium hypophosphite. The reducing agent is at least one of ascorbic acid, ferrous sulfate, and sodium formaldehyde sulfoxylate.

2. The dewatering agent for filter soil according to claim 1, characterized in that, The flocculant is anionic polyacrylamide with a molecular weight of 8 million to 12 million and an ionicity of 10% to 20%.

3. The dewatering agent for filter soil according to claim 1, characterized in that, The organosilicon hydrophobic agent is one or more of n-octadecyltriethoxysilane, n-hexadecyltrimethoxysilane, and dodecylmethyldimethoxysilane.

4. The dewatering agent for filter soil according to claim 1, characterized in that, The air-entraining agent is one or more of sodium dodecylbenzenesulfonate, sodium dodecyl sulfonate, and sodium dodecyl sulfate.

5. The dewatering agent for filter soil according to claim 1, characterized in that, The emulsifier is one or more of fatty alcohol ether phosphate and fatty alcohol polyoxyethylene ether sodium sulfate; the suspending and dispersing agent is one or more of waterborne polyamide wax and alkylphenol ether sulfosuccinate sodium.

6. The dewatering agent for filter soil according to claim 1, characterized in that, The water-reducing agent has a molecular weight of 200,000 to 500,000 and a PDI of 1.2 to 1.

6.

7. The dewatering agent for filter soil according to claim 1, characterized in that, The water-reducing agent is prepared by: S1. Prepare a base material with a concentration of 30% by adding water to diunsaturated carboxylic acids or anhydrides, anionic functional monomers and benzene ring monomers, heat to 45~70℃ and stir to dissolve, add oxidant and stir well; S2. Prepare a 40%~50% solution of monounsaturated carboxylic acid, prepare a 5% mixed solution of chain transfer agent and reducing agent, and prepare a 0.1% solution of crosslinking monomer. Add solutions A, B and C dropwise to the substrate over 3~3.5 hours for reaction. After the reaction is complete, keep warm for 1 hour and add the remaining water.

8. The dewatering agent for filter soil according to any one of claims 1-5, characterized in that, The method of using the filter soil dewatering agent is as follows: the sand and gravel aggregate washing slurry is introduced into the sewage neutralization tank and stirred by a mixer to achieve homogenization. Then, it is lifted by a lift pump to the sludge rapid settling tank. First, component I of the filter soil dewatering agent is added by a vibratory dosing device. The mixer is turned on and stirred for 1-2 minutes. After standing for 30-60 minutes, the upper layer of water overflows into the clear water storage and reuse tank and is used for recycling. Component II of the filter soil dewatering agent is added to the lower layer of slurry and stirred once at regular intervals. Then, it is sent to the plate and frame filter press by a screw pump for solid-liquid terminal separation by high-pressure diaphragm filtration.

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