230results about How to "Shorten the setting time" patented technology

The invention discloses a light spray coating and a construction process thereof. The light spray coating comprises 15-20% of cement, 15-20% of plant particles, 35-40% of building material particles, 15-18% of clay, 5-8% of siliceous superfine powder, 3-5% of cellulose, 3-5% of alumina micropowder and 0.02-0.05% of aluminum powder. The construction process comprises the following steps: S1, mixing and stirring the light spraying material, adding water accounting for about 3% of the total weight of the light spraying material for wetting, forming a semi-dry material, and filling the semi-dry material into a powder tank of a powder spraying machine; s2, a semi-dry method is adopted for spraying, the semi-dry material in the step S1 is fed into a muzzle of a powder spraying gun, atomized water is added into the muzzle, and the semi-dry material is sprayed to a construction part in the sequence of water first and material second; and rubber powder is added into the atomized water. The materials in the spray coating are simple and easy to obtain, the cost is low, the effects of comprehensive reinforcement and no influence on the internal ecology of the soil can be achieved, the construction is simple and rapid, and a construction foundation does not need to be built; the setting time is extremely short, and the construction period is not delayed; the terrain does not need to be considered, the construction surface is smooth, and the original construction part is not changed too much.

The invention relates to a synchronous grouting material based on muddy silt shield muck and a preparation method thereof, and the synchronous grouting material comprises the following raw materials in parts by weight: 13 to 16 parts of cement, 16 to 20 parts of slag, 142 to 147 parts of fine sand containing silt powder, 0.03 to 0.1 part of trimethylsilyl ethyl acetate, 0.07 to 0.17 part of disodium hydroxyethylphosphonate, 0.03 to 0.1 part of pentasodium amino trimethylene phosphonate and 63 to 67 parts of water. According to the invention, the fine sand containing mud powder is used as a main raw material to replace bentonite and fine sand in synchronous grouting in the prior art, and is combined with a specific cement additive, so that the compressive strength and the impermeability of the synchronous grouting material are effectively improved through the synergistic effect of the components, local materials can be used, and the outward transportation and disposal cost of a large amount of muck can be greatly reduced.

The invention discloses low-carbon flow-state solidified soil for a seasonal frozen region. The low-carbon flow-state solidified soil comprises soil, a curing agent and water, the dosage of the curing agent is 15-20% of the mass of the dry soil; the water content is 40-60% of the dry mass of the soil and the curing agent; the soil comprises sludge and building residue soil, and the sludge accounts for 20-40 parts by weight, and the building residue soil accounts for 60-80 parts by weight; the curing agent is prepared from the following components in parts by weight: 40 to 60 parts of phosphogypsum, 10 to 15 parts of mixing plant waste slurry, 20 to 40 parts of steel slag, 5 to 10 parts of quick lime, 0.5 to 1.2 parts of glycerol, 0.2 to 0.6 part of hydroxypropyl methyl cellulose and 1 to 1.5 parts of water reducing agent; according to the invention, various technical problems of insufficient anti-freezing performance, unstable fluidity, long setting time, insufficient early strength, large shrinkage deformation, easy generation of segregation and bleeding and the like of the existing fluid-state solidified soil are solved, and meanwhile, more low-carbon environment-friendly raw materials are introduced, so that multi-aspect improvement of the performance of the fluid-state solidified soil and maximization of environment-friendly benefits are realized; and a more reliable and efficient solution is provided for earthwork such as foundation pit backfilling.

The invention discloses a mineral powder-red mud-desulfurized gypsum-based multi-source solid waste road grouting material as well as a preparation method and application thereof, and belongs to the technical field of solid waste utilization and road grouting reinforcement. The mineral powder-red mud-desulfurized gypsum-based multi-source solid waste road grouting material comprises a multi-source solid waste aggregate and 0.01-0.015 wt% of a water reducing agent mixed in the multi-source solid waste aggregate, wherein the multi-source solid waste aggregate is prepared from the following raw materials in percentage by weight: 40.5-43.5 wt% of red mud, 40.5-43.5 wt% of quick-hardening sulphoaluminate cement, 9-10 wt% of mineral powder and 3-10 wt% of desulfurized gypsum; the mass ratio of the red mud to the quick-hardening sulphoaluminate cement is 1: 1. The mineral powder-red mud-desulfurized gypsum-based multi-source solid waste road grouting material can be hydrated to generate spar with a supporting effect, so that the grouting material has high stone strength in an early stage and high stone strength stability in a later stage, and generated spar particles can interact with a water reducing agent; and meanwhile, the problem of stockpiling of contained solid wastes is effectively solved, and the preparation cost is greatly reduced.

The invention belongs to the technical field of solid waste resource utilization, and discloses a belite-aluminate mineral additive and a preparation method and application thereof.The belite-aluminate mineral additive is prepared from, by mass, 25-40 parts of alumina tailing slag, 60-65 parts of carbide slag, 1-8 parts of coal gangue, 0.1-0.5 part of CaF2, 2-8 parts of fluorgypsum and 0.1-0.5 part of borax. The prepared belite-aluminate mineral additive mainly comprises monocalcium aluminate, dodecacalcium heptaaluminate, dicalcium silicate and tetracalcium aluminoferrite, when Portland cement is modified with the doping amount of about 10%, the setting time of the cement can be effectively shortened, the early strength can be improved, the performance is excellent, low-temperature calcination is achieved, and energy is saved.

The invention discloses a springback inhibitor for sprayed concrete as well as a preparation method and application of the springback inhibitor. The rebound inhibitor is prepared from the following components in percentage by mass: 2-5% of magnesium aluminum silicate, 19.8-29.8% of silica fume, 1-4% of a macromolecular tackifier, 2-5% of aluminum sulfate slag powder, 38-51% of superfine stone powder, 9-16% of fly ash microspheres, 1-2% of a water reducing agent, 2-3% of redispersible milk powder, 2-5% of inorganic mineral fibers and 0.01-0.2% of modified plant fibers. The springback inhibitor disclosed by the invention has a remarkable effect on reducing the springback rate of the sprayed concrete, and can enhance the water dispersibility resistance of the sprayed concrete and improve the cohesiveness of the sprayed concrete. The preparation method disclosed by the invention is simple in industry and easy for large-scale production.

The invention relates to a preparation method of a C-S-H seed crystal type super early strength agent as well as a product and application of the C-S-H seed crystal type super early strength agent, and belongs to the technical field of production of cement-based materials. According to the preparation method, the C-S-H seed crystal type super early strength agent is obtained by mainly utilizing a microwave irradiation principle and taking a siliceous raw material, a calcium raw material, a dispersing agent, an organic complexing exciting agent and water as raw materials to react. The preparation method provided by the invention is short in reaction time, and the synthesized C-S-H seed crystal type super early strength agent has the characteristics of good early strength effect, good stability, greenness and harmlessness, can be widely applied to various product concrete and cast-in-place concrete projects, and has wide research background and important significance in the field of synthesis of composite materials such as concrete admixtures.

The invention discloses a low-carbon masonry cementing material as well as a preparation method and application thereof. The low-carbon masonry cementing material is prepared from the following raw materials in parts by weight: 95-100 parts of ceramsite waste residue powder, 1-10 parts of magnesium aluminum silicate slag and 0-4 parts of clinker, the low-carbon masonry cementing material contains a large amount of amorphous active silicon, and under the direct excitation hydration action of the magnesium aluminum silicate slag component, the hydration rate of the low-carbon masonry cementing material is promoted, so that the low-carbon masonry cementing material has the characteristics of improved early and long-term strength, strong durability, high water retention rate and small hydration heat; besides, by adding the clinker, mineral components such as CaO, SiO2 and Al2O3 can be released and promoted to be subjected to a hydration reaction, C-S-H series hydrates and ettringite are generated, and the artificial stone is coagulated and hardened into the hard artificial stone at the normal temperature like cement.

The invention relates to the technical field of building materials, and provides a preparation method of a functional fiber modifier, the modifier and application of the modifier in precast concrete.The method comprises the steps that S1, a calcium raw material is added into water to be stirred and mixed, sealed standing and aging are conducted for 20-48 h, a mixed solution is obtained, and the temperature of the water is controlled to range from 80 DEG C to 100 DEG C; s2, adding a siliceous raw material and a structure-directing agent into the mixed solution, uniformly mixing, and adding into a reaction kettle; s3, the temperature of the reaction kettle is controlled to rise, meanwhile, the stirring rotating speed is controlled to be 200-400 rpm, when the temperature rises to 180-220 DEG C, the stirring rotating speed is controlled to be 50-70 rpm, and heat preservation is conducted for a reaction; s4, after the reaction is finished, cooling, taking out slurry, filtering and drying to obtain functional fibers; and S5, dispersing the reinforcing agent in water, adding the functional fibers, and stirring for reaction to obtain the functional fiber modifier. According to the technical scheme of the invention, the functional fiber modifier has obvious rapid hardening and early strength effects, has no adverse effect on concrete performance, and can realize energy saving and steam curing-free and rapid demolding to improve the template turnover rate.

The invention provides a low-cost admixture for shotcrete and a preparation method thereof. The raw materials for preparing the admixture include the following components by weight percentage: 40% to 50% silica fume, 5% to 10% fast-hardening sulphoaluminate cement, 35% to 45% reinforcing agent, 2% to 4% dispersant, 1% to 2% shrinkage reducing agent, and 0.5% to 1% regulator. The raw materials for the shotcrete admixture are widely available, cheap and easy to obtain, can significantly improve the cohesiveness and pumpability of the shotcrete, shorten the setting time of the shotcrete, have high bonding strength with the rock base, reduce the rebound rate of the shotcrete, and greatly save the project construction cost.

The invention provides an alkali-free fluorine-free liquid accelerator and a preparation method thereof, the alkali-free fluorine-free liquid accelerator comprises the following components: soluble aluminum salt, a dispersant, a pH regulator, an early strength agent, polymeric alcohol amine and water, and the polymeric alcohol amine is obtained by polymerization reaction of an acrylate monomer, a polyamine monomer and an alkyl ethylene oxide monomer. According to the accelerator, the complexing ability to aluminum ions is improved by introducing polymeric alcohol amine, so that the solubility and the stability of the aluminum ions are improved, meanwhile, the solubility of amide groups can be improved by hydrophilic groups in chain segments of the polymeric alcohol amine, the setting time of concrete is shortened, and the early strength of the concrete is improved.

The invention discloses a preparation method and application of a liquid alkali-free accelerator, and belongs to the technical field of rapid-setting materials in the building industry. The preparation method comprises the following steps: uniformly mixing a solution containing aluminum sulfate and a fluosilicic acid solution to obtain a first mixed solution, then adding a second mixed solution containing a sodium metaaluminate additive and sodium hydroxide into the first mixed solution, and reacting at 100-110 DEG C for 1-2 hours to obtain the liquid alkali-free accelerator, wherein the second mixed solution containing the sodium metaaluminate additive and the sodium hydroxide is prepared by gradually adding aluminum hydroxide solid into a sodium hydroxide solution for reaction, and the molar ratio of the sodium hydroxide to the aluminum hydroxide is (1.35-1.45): 1; the solid content of the obtained liquid alkali-free accelerator is 40-50%, and the pH value of the liquid alkali-free accelerator is 1.5-3.0. The method is easy to operate, raw materials are easy to obtain, and the obtained accelerator is high in stability, good in concrete setting effect and high in setting strength and has a wide application market.

The invention discloses anti-crack mortar for an assembly type light partition wall board. The anti-crack mortar is prepared from the following raw materials: Portland cement, redispersible latex powder, hydroxypropyl methyl cellulose ether, gypsum powder, fly ash, anti-crack fibers, water, polyphenyl granules, light mineral waste residues, a foaming agent, an early strength agent, a foam stabilizer, a waterproof agent, a water reducing agent, an accelerator and a reinforcing agent. The mortar can be used for manufacturing light partition boards or connecting two light wall materials, the manufacturing process of the wall materials produced by the mortar is simple, the wall materials are easy for later decoration, the problems of surface cracking, water seepage and easy moisture of a traditional wall board are solved, compared with the traditional wall board, the mortar has the advantages of light weight, combustion resistance, strong permeability release property and the like, the production process is pollution-free, and the mortar is suitable for large-scale popularization and application. The finished wall material is convenient to use in the building process and has high practical value.

The invention belongs to the technical field of slope support, and relates to a support device for high-altitude area mine geological disaster control, which comprises concrete columns, the concrete columns are arranged in a staggered manner to form a grid, steel bars are poured and fixed in the concrete columns, and the support device further comprises an anchoring assembly and a semiconductor temperature control assembly. The anchoring assembly comprises an anchor rod and a connecting piece, the anchor rod is arranged to be a hollow rod body, the connecting piece comprises a shell, the shell is detachably connected with the anchor rod, and the shell is provided with a limiting hole for the steel bar to penetrate through. The semiconductor temperature control assembly comprises a cold end and a hot end, the cold end and the hot end are connected through direct current, the cold end is arranged in the anchor rod, temperature conduction is conducted between the cold end and the anchor rod, and the cold end is used for cooling a frozen soil layer, so that the phenomenon that the frozen soil layer is excavated while the frozen soil layer is excavated is reduced, and the stability of slope protection is improved; and the hot end and the steel bars conduct temperature and are used for heating the concrete column, the setting time of the concrete column can be shortened, and the strength of the concrete column is improved.

The invention provides a mine filling cement material capable of cementing high-content phosphate tailings as well as a preparation method and a use method thereof, relates to the technical field of mine filling materials, and solves the technical problems that the existing mine filling cement material cannot shorten the setting time and improve the setting strength of the material while reducing the bleeding rate. The high-strength concrete is prepared from the following components: 40 to 45 weight percent of slag, 7 to 10 weight percent of metakaolin, 8 to 10 weight percent of yellow phosphorus slag, 0 to 5 weight percent of phosphogypsum, 35 to 40 weight percent of cement clinker, 1 to 5 weight percent of exciting agent and 1 to 5 weight percent of mineral admixture, the mineral admixture is prepared from bentonite, sepiolite and attapulgite. According to the invention, the setting time can be effectively shortened, the bleeding rate is effectively reduced, the filling time is shortened, the underground drainage and filling cost is reduced, the pollution to the water environment of a mining area is reduced, the effective utilization of the phosphate tailings is realized, and the stacking of the phosphate tailings and the environmental pollution are reduced; the condensation speed and the strength of the filling body can be effectively improved; the comprehensive performance of the material is improved.

The invention relates to the technical field of food, in particular to a method for accelerating coagulation of coagulated yoghurt and enhancing water-holding capacity and hardness, black rice coagulated yoghurt, black rice leavening and application. The preparation method of the solidified yoghurt capable of accelerating milk curding and enhancing water-holding capacity and hardness through black rice fermentation is characterized by comprising the following steps: preparing sterile pretreated black rice; preparing a fermentation seed solution; preparing fermented black rice: adding the fermented seed solution into the sterile pretreated black rice, uniformly mixing, and standing and fermenting for 60-96 hours at the temperature of 30-35 DEG C and the humidity of 70-80%; the preparation method comprises the following steps: preheating cow milk to 43 DEG C, adding fermented black rice (1: 7-1: 10, w / v), further adding a yoghurt fermentation inoculant (3: 1600, w / v), fully stirring and uniformly mixing, standing and fermenting at 42-44 DEG C for 4-6 hours, and refrigerating at 4 DEG C for 12 hours after the yoghurt is completely solidified, thereby obtaining the black rice step-by-step co-fermentation solidified yoghurt.

The invention belongs to the technical field of phase change energy storage, and particularly relates to a cascade phase change heat storage device which comprises an inlet, an outlet and a heat storage device body. The heat storage device body is composed of a shell, a plurality of finned tubes and a phase change material. The finned tube comprises a circular base tube and two-way staggered fins; layering partition plates are arranged in the heat storage device, and the phase change material filling area is divided into an upper area, a middle area and a lower area according to the height. Due to the fact that hot fluid flows in from the upper portion of the heat storage device, exchanges heat with the phase-change materials and then flows out from the lower outlet, the upper area is filled with the high-temperature phase-change materials, the middle area is filled with the medium-temperature phase-change materials, and the lower area is filled with the low-temperature phase-change materials. When flowing through the heat storage device from top to bottom, the hot fluid always keeps relatively stable temperature difference with the phase change materials in different areas, a large amount of heat energy can be stored in a small size, and therefore the heat efficiency of the heat storage system is improved.

The invention discloses high-temperature large-temperature-difference early-strength low-density well cementation cement slurry and a preparation method thereof, and relates to the technical field of oil and gas well cementation. The well cementation cement slurry comprises the following components in parts by mass: 100 parts of oil well cement; 15-35 parts of a high-temperature strength stabilizer; 10-30 parts of a lightening agent; 0.2 to 0.6 part of an early strength agent; 0.3 to 0.7 part of a high-temperature suspension stabilizer; 1-5 parts of a high-temperature fluid loss agent; 0.3 to 0.7 part of a high-temperature retarder; and 50-70 parts of water. The problems that in the prior art, large-temperature-difference low-density cement paste is poor in rheological property, too large in water loss, poor in high-temperature stability, slow in strength development and the like are solved, safe well cementation construction of a long-sealing-section easy-leakage stratum is achieved, and therefore efficient and safe exploitation of deep stratum oil and gas resources is guaranteed.

The invention relates to a multi-component cement-based repairing material which comprises the following components in percentage by mass: 0-30% of Portland cement and fly ash, 5-50% of sulphoaluminate cement, 1-2.5% of rubber powder and 0.1-0.25% of polypropylene fiber. The standard mixing ratio of the cement to the water to the sand is 1: 0.5: 1. Portland cement and fly ash are used as main repairing materials, and microcracks of an existing structure can be repaired; the polypropylene fiber can improve the crack resistance; on the basis, soluble rubber powder and epoxy resin are introduced, so that the anti-permeability performance of the repairing material is further improved. Meanwhile, the sulphoaluminate cement and the accelerator greatly reduce the setting time of the cement-based material, so that the comprehensive performance of the defective structure can be quickly improved within a short time. The silica fume is doped into the Portland cement-based repairing material, so that the early strength and compactness of the repairing material are improved. The preparation method is simple in steps, convenient to use, energy-saving and environment-friendly.

This invention discloses an early-strength, high-stability road grouting repair material and its preparation, belonging to the field of solid waste utilization and road grouting reinforcement technology. The raw materials of the early-strength, high-stability road grouting repair material of this invention include multi-source solid waste aggregates and a water-reducing agent; the multi-source solid waste aggregates, by mass percentage, include: 6.6 wt% fly ash, 5-15 wt% rapid-hardening sulfoaluminate cement, 64-74 wt% mineral powder, 13.4 wt% desulfurized gypsum, and 1% carbide slag. This invention constructs a quaternary solid waste system of fly ash-desulfurized gypsum-mineral powder-carbide slag, synergistically forming a slurry composite system with rapid-hardening sulfoaluminate cement and a water-reducing agent, and precisely controls the concentration of raw materials. During hydration, this system can generate supporting crystals, which not only provide high early-stage stone strength for the road grouting material, but also, due to its good stability, ensure high stone strength stability in the later stages.

The present invention discloses a self-vibrating steel table formwork and production line for intelligent prefabricated concrete components, including a platform part, a supporting part and an electric control device. The platform part includes a table formwork steel plate, a platform frame and a plurality of vibration motors. The table formwork steel plate is horizontally fixed to the top of the platform frame, and the vibration motor is hoisted to the bottom of the platform frame; the supporting part includes a support body and a spring. The support body includes at least two long steel bodies arranged at the bottom of the platform frame and arranged parallel to each other. Each long steel body is connected to the platform frame through a plurality of springs, and the electric control device is connected to the vibration motor for communication. The technical effect of the present invention is that the present invention adopts a self-vibrating and integrated design. There is no need to combine multiple small vibration tables. The motor is directly connected to the table formwork, eliminating the gap caused by splicing, so that the vibration of the concrete can be more uniform, and the noise in the vibration production process can be significantly reduced.

The invention relates to the technical field of fabric setting, in particular to a fabric shrinkage rate rapid setting method, and aims to solve the problems that the production cycle is prolonged, the production efficiency is greatly reduced, the fabric setting effect is poor, the energy and raw material consumption is large and the like due to long setting time in the prior art. According to the original area of the fabric, taking a corresponding area for analysis; compared with a traditional shaping method, the rapid shaping method adopting the shrinkage rate has the advantages that the shaping time can be remarkably shortened, the production efficiency can be improved, the production cycle can be shortened, the consumption of energy and raw materials can be reduced, and the production cost can be greatly reduced; by optimizing the formula, equipment and process parameters, researching the physicochemical properties of the fabric and selecting the optimal temperature for fabric setting, the stable and consistent fabric setting effect is realized, and the quality stability of the product is improved.

The utility model provides a cooling device for an investment casting casting, and belongs to the technical field of machinery. The problem that in the prior art, applicability is poor is solved. The investment casting cooling device comprises a bottom plate, a top plate, a screw rod, a guide rod, a moving plate, a cooling fan and a placing disc, the top plate and the bottom plate are oppositely arranged up and down, the screw rod is rotationally connected between the bottom plate and the top plate, the guide rod is fixedly connected between the bottom plate and the top plate, and the screw rod and the guide rod are oppositely arranged. A main motor is connected to the top plate, the output end of the main motor is connected with the screw, one end of the movable plate is in threaded connection with the screw, the other end of the movable plate is movably connected to the guide rod in series, the cooling fan is connected to the upper portion of the top plate, and an air outlet pipe of the cooling fan penetrates through the top plate and right faces the movable plate. The bottom of the moving plate is connected with a driving assembly, the containing disc is connected with the driving assembly, and the driving assembly can drive the containing disc to rotate. The investment casting casting cooling device is high in applicability.

The invention discloses an alkali-sulfate-aluminum salt ternary composite excitation cementing material and application, and belongs to the technical field of mine filling materials. The material consists of the following components in parts by weight: 65-80 parts of blast furnace slag micro powder, 20-30 parts of sulfate, 5-10 parts of alkali and 0.5-5 parts of an aluminum salt admixture, wherein the blast furnace slag micro-powder is obtained by grinding granulated blast furnace slag for blast furnace ironmaking or crude steel smelting. The application of the ternary composite excitation cementing material is specifically used for preparing filling slurry, and comprises the following steps: weighing the raw materials according to the ratio of lime to sand, uniformly mixing and stirring, then weighing the mixing water, and uniformly mixing to obtain the filling slurry. According to the prepared cementing material, the porosity and the free water content of a filling body can be reduced, the compressive strength of the filling body is remarkably improved compared with a cement filling body and an alkali-sulfate binary excitation filling body under the same condition, meanwhile, the setting time is shortened, the early strength is improved, and the mine filling efficiency is remarkably improved.

The invention relates to the technical field of refractory materials, in particular to preparation and application of a refractory energy-saving fused zirconia corundum brick. The preparation method of the refractory energy-saving fused zirconia corundum brick comprises the following steps: S1, crushing and purifying raw materials; S2, melting in an electric arc furnace; and S3, pouring, preserving heat, annealing and forming. In the raw materials used in the preparation method, sodium polysulfonate and rare earth oxide are added, the raw materials are subjected to strong magnetic iron removal in the raw material treatment stage, a cooling and heat preservation process is added in the pouring, heat preservation, annealing and forming step, silica sol is added in the heat preservation process, and the like, so that the fire resistance and corrosion resistance of the zirconia corundum brick are greatly improved; and the setting time of the zirconium corundum brick finished product is shortened, the service life of the zirconium corundum brick finished product is prolonged, and the maintenance and replacement cost is reduced. The zirconium corundum brick prepared by the preparation method of the refractory energy-saving electric smelting zirconium corundum brick can be applied to glass industrial pools, furnace pools for metallurgy, reactors, heaters and the like in the chemical industry.

The utility model relates to deep hole machining device technical field discloses die casting deep hole finish machining device, including female die, male die, work piece deep hole positioning cavity, extrusion pin mechanism, drive mechanism and deep hole cooling mechanism. Adopt this structure, can move through drive mechanism and push extrusion pin mechanism, force push the metal liquid that has not solidified fills the contraction space, breaks the problem of outer layer solidification hindering make up, and the pressure makes the metal structure of work piece more dense, reduces the blowhole, loose of deep hole setting place, improves air tightness, and simultaneously is provided with deep hole cooling mechanism, and extrusion pin mechanism can quickly absorb the heat of die casting work piece deep hole wall thickness place, accelerates the solidification speed from surface layer to core, shortens the solidification time of die casting work piece deep hole position, and improves cooling uniformity, effectively avoids the problem that the shrinkage cavity leads to the problem that the rejection rate is too high.

The invention discloses a low-temperature fluid loss agent and a preparation method thereof, the low-temperature fluid loss agent is prepared by polymerizing the following components: 2-acrylamido-2-methylpropanesulfonic acid, an amide monomer, a carboxylic acid monomer, a molecular regulator and an additive, and the additive is di (triethanolamine) diisopropyl titanate. The preparation method comprises the following steps: sequentially adding water, 2-acrylamido-2-methylpropanesulfonic acid, an amide monomer, a carboxylic acid monomer and a molecular regulator into a three-neck flask with a thermometer and a stirrer to obtain a reaction solution; stirring the reaction liquid, adjusting the pH value to 7, and heating; adding an initiator, and continuously reacting; and adding an additive, stirring, drying and crushing to obtain the fluid loss agent. The additive di (triethanolamine) diisopropyl titanate added in the invention has coupling and early strength characteristics due to a unique structure, can realize good compatibility with anhydrous sodium metasilicate, and can meet the requirements of low water loss, short cement setting time and fast strength development when the addition amount of the additive di (triethanolamine) diisopropyl titanate is low in the cement.

The invention discloses a solid waste superfine powder grouting material for shield tunneling and a muck recycling method, and relates to the technical field of shield tunneling. The solid waste superfine powder grouting material for the shield comprises cement, fly ash, bentonite, a water reducing agent and shield muck serving as aggregate. The invention further discloses a muck recycling method based on the shield muck. The shield muck is shield muck generated in the tunneling process of a shield tunneling machine. Mixing the cement, the fly ash, the bentonite, the water reducing agent and the shield muck serving as the aggregate, stirring the mixture with water to form recycled slurry, and using the recycled slurry as a synchronous grouting material; the purposes of recycling the shield muck, reducing the use amount of field sandy soil and saving the cost are achieved.

The invention relates to the technical field of medical dressings, in particular to a medical dressing for wound care and a preparation method thereof. The medical dressing is prepared from the following raw materials in percentage by mass: 15 to 25 percent of gelatin, 1 to 5 percent of gracilaria lemaneiformis polypeptide-hydroxyapatite compound, 3 to 8 percent of modified hydroxypropyl starch, 0.1 to 0.5 percent of xanthan gum, 0.05 to 0.1 percent of polyethylene glycol and the balance of water. According to the medical dressing disclosed by the invention, components such as the gracilaria lemaneiformis polypeptide-hydroxyapatite compound, the modified hydroxypropyl starch and the like are added into a formula of the medical dressing. The gracilaria lemaneiformis polypeptide-hydroxyapatite compound can effectively shorten the blood coagulation time, so that the wound healing speed is accelerated; and the modified hydroxypropyl starch can effectively improve the long-acting antibacterial effect of the medical dressing.

The invention discloses a method for carbonizing-solidifying natural latex by adopting CO2 microbubbles under normal pressure. The method comprises the following steps: 1) introducing carbon dioxide into a microbubble generating device from a gas inlet; 2) adding natural latex into a microbubble generating device from a material inlet; 3) contacting the carbon dioxide with the natural latex in a microbubble form under a normal pressure condition; and 4) collecting the natural latex at a material outlet, and standing and solidifying to obtain the natural rubber clot. According to the invention, CO2 microbubbles are adopted to solidify natural latex, and the microbubbles provide larger specific surface area and longer retention time to significantly accelerate the dissolution process of gas in liquid. The method is mild in process condition, and can be carried out under normal pressure and realize continuous operation; latex solidification speed is fast, and time is less than or equal to 1h; the finally prepared natural rubber product is good in quality, the initial plasticity value is larger than or equal to 40, the plasticity retention rate is larger than or equal to 92, and the tensile strength after vulcanization is larger than or equal to 24 MPa.