290 results about "Cement paste" patented technology

The invention relates to the technical field of drilling compositions, in particular to a composite plugging agent, a plugging composition and plugging cement paste for shale gas formation cracks. The composite plugging agent for shale gas stratum cracks is composed of a bridging material, a filling material and an end-capping material, the mass ratio of the bridging material to the filling material to the end-capping material is (1.2-1.4): 0.5: (0.1-0.3), the bridging material is organic fibers with the length of 3-5 mm, the filling material is composed of inert particles with the particle size of 35-280 [mu] m and micro-silicon with the particle size of 0.15-1 [mu] m, and the end-capping material is a mixture of silicon oxide and silicon oxide. The end-capping material is composed of organic fibers with the length of 8-9 mm and walnut shells with the particle size of 3-5 mm. Through compounding of different types of bridging materials, filling materials and end sealing materials and grading of fibers with different lengths and plugging particles with different particle sizes, the plugging agent can be matched with cement paste in complex cracks and large cracks (1-4 mm) of a stratum to form a stable and compact plugging layer, the compressive strength is high, effective retention is achieved, and the effect of plugging a complex leakage layer is achieved.

The invention discloses a seabed shallow casing section thermal insulation structure for polar region supercritical carbon dioxide drilling, which comprises a casing, a thermal insulation coating, a protective coating, an annular cement slurry layer, an electric heating pipe, a sensor module, a wireless conductive module, a ground system and a seabed wireless transmission module, and is characterized in that the electric heating pipe is fixed on the outer wall of the casing through a hoop; the outer wall of the casing pipe is sequentially coated with a heat preservation coating, a protective coating and an annular cement paste layer from inside to outside, the wireless conductive module is integrated at the end of the casing pipe, and the ground system comprises a ground data acquisition system and a ground control center. The sea surface platform is provided with a ground data acquisition system and a ground control center which are connected with the seabed wireless transmission module through an umbilical cable, and temperature and pressure data acquired by the sensor module are uploaded to the ground control center. According to the invention, the problems of rapid heat loss, annular air channeling, casing mechanical property degradation, poor drilling fluid fluidity and the like of the seabed shallow casing section in the polar region extreme low-temperature environment are solved.

The application discloses a high-value resource utilization system and method of waste concrete, and the system comprises a preheating subsystem, a calcining subsystem, a cooling subsystem, a separating subsystem, a crushing subsystem, a dust collecting subsystem and a conveying subsystem. Waste concrete which is coarsely separated and pre-homogenized is mixed into cement raw materials to produce silicate cement clinker, and the test block after coarse crushing, screening, fine crushing and screening is directly stripped, and the separated powder can be used as a mixing material; the test block after stripping is preheated and calcined in a rotary kiln, the obtained material is cooled and stripped, and then sent into a V-type powder separator to separate coarse aggregates, and the fine aggregates and recycled waste concrete micro powder are separated through the powder separator and a dust collector. The application realizes the synergistic effect of pollution reduction and carbon reduction by combining with a cement production line, separates fine aggregates, coarse aggregates and hardened cement paste in the waste concrete, and realizes the high-value resource utilization of the waste in multiple ways according to the characteristics of each component.

The application provides a kind of concrete chloride ion diffusion coefficient prediction method based on aggregate gradation, comprising the following steps: obtaining the chloride ion diffusion coefficient D ref Of cement paste;Obtaining the specific surface area s i Of aggregate in each particle size interval;Obtaining the thickness of concrete interfacial transition zone;Calculating the chloride ion diffusion coefficient of concrete.The application considers the influence of all components (cement paste, aggregate, interfacial transition zone) on chloride ion diffusion coefficient from the composition of concrete, and the influence of aggregate particle size on the thickness of interfacial transition zone, and the prediction result has high accuracy, which can provide effective reference for the evaluation of concrete resistance to chloride ion erosion.

The invention discloses a full-automatic cement setting time determinator and a determination method thereof, and belongs to the technical field of cement setting time determination. The determinator comprises a constant temperature and humidity chamber and an electric cabinet, an initial setting time determination device and a final setting time determination device are respectively arranged in the constant temperature and humidity chamber, the electric cabinet is arranged on the constant temperature and humidity chamber, a controller is arranged in the electric cabinet, a touch screen is arranged on an opening in the side wall of the electric cabinet, and the touch screen is connected with the controller. And the controller is electrically connected with the constant temperature and humidity chamber and the touch screen. All the two test molds filled with cement paste can be simultaneously put into the constant-temperature and constant-humidity chamber for curing, so that the whole cement setting time measuring period is remarkably shortened, the measuring efficiency is improved, and full-automatic cement setting time measuring is really realized; the test mold and the to-be-tested piece on the inner side of the test mold do not need to be overturned in the testing process, so that the whole testing process is safely and smoothly carried out; the whole cement setting time determination process is simple, the determination period is short, and the determination efficiency is high.

The invention belongs to the field of cement paste for well cementation of oil and gas wells, and particularly relates to medium-high temperature anti-gas channeling cement paste. The medium-high temperature anti-gas channeling cement paste comprises water and the following raw materials in parts by weight: 100 parts of oil well cement, 35-40 parts of a high-temperature strength stabilizer and 2-3 parts of an anti-gas channeling agent, the high-temperature strength stabilizer is prepared from SiO2 with the particle size of 75 to 100 mu m, SiO2 with the particle size of 23 to 38 mu m and SiO2 with the particle size of 0.1 to 10 mu m according to the mass ratio of 10 to (20 to 21) to (1.2 to 1.5); the anti-gas channeling agent is a copolymer of 2-acrylamide-2-methylpropanesulfonic acid, acrylamide and N, N '-dimethylacrylamide. The cement paste disclosed by the invention has relatively high fluidity, relatively good defoaming property, relatively high gas channeling prevention performance and relatively high high-temperature stability, has relatively high strength and gas channeling prevention performance after well cementation, can prevent the gas channeling problem of well cementation, and improves the well cementation quality.

The utility model discloses a stirring dust removal mechanism of a concrete stirring station, which belongs to the field of concrete stirring station equipment and comprises a stirrer, a dust removal water tank and a track which are arranged in the concrete stirring station. The stirrer is fixedly mounted in the protective frame, and rollers are mounted at the bottom of the protective frame and placed on the rails in a matched manner; an exhaust hole and a water inlet hole are formed in the top of the stirrer, and the tail end, connected with an exhaust pipe, of the exhaust hole extends into the dust removal water tank; the water inlet is connected with the tail end of the water pumping pipeline and extends into the dedusting water tank. According to the dust removal device, dust can be effectively removed, and sewage generated in the using process, such as waste water generated by cleaning a cement paste mixer and a concrete mixing main machine, is recycled into the dust removal water tank and is reused, so that the problems of dust raising and waste recycling in the processing process are well solved; the dust removal water tank can remove dust and can also play a role in water storage, and the problem that a water storage tank is additionally arranged is solved.

The application provides a cement-based composite material and a preparation method thereof, and belongs to the technical field of composite material preparation.The application comprises the following steps: step one, preparing heat-conducting and enhanced phase change energy storage microcapsules with uniform and controllable particle sizes; step two, preparing heat-conducting and enhanced phase change energy storage microcapsules with controllable wall thicknesses; and step three, preparing a phase change energy storage cement-based composite material test piece.The application prepares heat-conducting and enhanced phase change energy storage microcapsules with uniform and controllable particle sizes through a microfluidic chip, controls the wall thicknesses of the microcapsules through a layer-by-layer self-assembly method, and finally adds the heat-conducting and enhanced phase change energy storage microcapsules with controllable wall thicknesses into a cement paste, so that the microcapsules are dispersed in the cement paste, and a phase change energy storage cement-based composite material with good heat regulation capacity is prepared.

The invention discloses a method and system for characterizing fresh cement paste bleeding, and the method comprises the steps: firstly selecting a bleeding process of fresh cement paste as a research object, obtaining scatter test data of bleeding amount changing along with time, then building a time-dependent model for characterizing the bleeding process of the fresh cement paste, deducing an analytical solution, and combining the test data to obtain a time-dependent model for characterizing the bleeding process of the fresh cement paste. Various parameters of the time-dependent model are determined, the bleeding curve of the fresh cement paste is quantified, the change rule of the bleeding process is simulated, and practical engineering application is guided. According to the method for representing the bleeding of the fresh cement paste, a time-dependent self-weight consolidation model is adopted, an analytical solution is clear, calculation is easy and convenient, simulation precision is high, the method has a wide engineering application background, and an effective theoretical tool can be provided for representing the bleeding process of the cement paste.

The invention discloses a lightweight high-strength concrete thermal insulation wallboard for a high-rise building and a preparation method of the lightweight high-strength concrete thermal insulation wallboard. The lightweight high-strength concrete thermal insulation wallboard comprises the following raw materials in parts by weight: 300-500 parts of cement, 60-90 parts of slag powder, 60-100 parts of silica fume, 60-90 parts of microbeads, 100-200 parts of floating beads, 500-900 parts of modified lightweight aggregate, 15-20 parts of alkali-resistant glass fibers, 25-40 parts of a water reducing agent and 180-220 parts of water. According to the invention, a layer of'hard shell 'is formed on the surface after the shale ceramsite is wrapped and reinforced by the light cement paste, the problem of high water absorption rate of the shale ceramsite is improved, meanwhile, the mechanical property of the shale ceramsite is improved, secondly, the self-made lightweight aggregate is low in water absorption rate and high in strength, the density of the self-made lightweight aggregate is close to that of a gelling matrix of the thermal insulation wallboard, and the aggregate can be prevented from floating or sinking; the floating beads are added into the modified lightweight aggregate, so that the prepared lightweight wallboard is good in homogeneity, low in water absorption and good in mechanical property, the weight of the wallboard can be reduced through cooperation of the floating beads in the thermal insulation wallboard and the modified lightweight aggregate, meanwhile, the floating beads have excellent fire resistance and heat insulation performance, and the heat insulation and fire resistance of the lightweight wallboard can be improved through cooperation of the floating beads and the alkali-resistant glass fibers with the high melting temperature.

A kind of waste rock-paste cooperative filling construction composite isolation layer multi-section high and steep goaf treatment method belongs to underground mining technical field. At the junction of upper and lower sections, a composite isolation layer of "pillar + high-strength cemented paste" is constructed to realize rigid support and flexible cushioning. Above the isolation layer, a combined filling mode of "waste rock + low-strength paste" is used. Through waste rock dumping and filling to build slope and low-strength paste covering, a cooperative bearing structure is formed. The advantages are that the composite isolation layer not only protects the lower unsampled ore, but also realizes ground pressure control through waste rock paste filling, reduces filling cost, and controls the subsequent ore dilution rate below 8%, reduces the comprehensive filling cost by 25%-35%. It is suitable for complex goaf treatment and sublevel mining scenarios in deep metal mines, coal mines and other underground mines.

The invention provides a construction method of a cast-in-place pile based on a bag type pile end. The construction method comprises the steps that a pile hole is drilled; the reinforcement cage carrying the pile end grouting assembly is sunk into the pile hole, the pile end grouting assembly comprises an annular bag steel plate and a bag fixed to the lower side of the bag steel plate, the bag steel plate and the bag are annular, center holes of the bag steel plate and the bag are communicated, and concrete is poured into the pile hole; first cement paste is injected into the bag, and meanwhile compressed air is injected into the lower portion of the bag, so that the paste at the bottom of the pile hole is discharged out of the ground; and after the concrete reaches the curing period, second cement paste is injected into the lower portion of the bag, and pile bottom grouting is conducted. When the bag sinks, slurry flows through the bag steel plate and the center hole of the bag, so that strong scouring of the slurry to the inner wall of the pile hole is avoided, and the total amount of muck at the bottom of the pile hole is reduced; and compressed air is used for cleaning the bottom of the pile hole, so that the grouting quality is improved, and the settlement amplitude of the pile body is reduced.

The present application relates to a kind of cellulose modified water purification type pervious concrete and preparation method, comprising: microcrystalline cellulose modification, with diabase as aggregate, with cement, fly ash, modified microcrystalline cellulose and water are mixed, forming, demolding, it is obtained.The present application, modified microcrystalline cellulose and fly ash form synergistic effect, the cement paste of pervious concrete is improved, and water retention can inhibit the phenomenon of slurry bleeding hole appears, and the structure performance of pervious concrete skeleton and paste is stable.Pervious concrete compressive strength, flexural strength increases, and because slurry bleeding hole phenomenon reduces, the water permeability of pervious concrete increases.Modified microcrystalline cellulose makes the purification capacity of pervious concrete further improve, and C-S-H gel in modified pervious concrete cement paste and modified microcrystalline cellulose ligand are coordinated to realize the adsorption of Cu (II), Cr (III), Zn (II), Pb (II) ion in water.Modified microcrystalline cellulose makes cement paste early hydration process slow down, and it is beneficial to reduce the generation of early surface crack of pervious concrete paste.

The utility model discloses a cement mortar gravel separating device, including shell, centrifugal mechanism, swing mechanism and discharge mechanism, wherein the centrifugal mechanism is provided in the shell, and centrifugal mechanism passes through the side wall of shell, be provided with the water storage cylinder above the centrifugal mechanism, the bottom surface of water storage cylinder is communicated with a plurality of nozzles, the water storage cylinder is communicated with the water pipe, and the water pipe is communicated with the swing mechanism. The water conveying pipe penetrates through the top wall of the shell, the swing mechanism is arranged on the shell and connected with the water storage barrel, a support is arranged below the shell, two mounting plates are oppositely arranged on the support and rotationally connected with rotating shafts, the two rotating shafts are connected with the two sides of the shell respectively, a hydraulic column is hinged between the support and the shell, and the hydraulic column is connected with the water storage barrel. The discharging mechanism is arranged at the bottom of the shell. Therefore, the outer wall of the centrifugal mechanism can be effectively washed, cement paste and fine sand attached to the outer wall of the centrifugal mechanism can be removed, the screen holes are prevented from being blocked, and the sand and stone separation efficiency is effectively improved.

This invention discloses a rapid-hardening, high-toughness shotcrete and its spraying construction method, belonging to the field of concrete material technology. It employs a technical route of multi-component synergistic rapid-hardening – modified hybrid fiber toughening – three-stage synergistic expansion – three-phase distribution spraying method. The shotcrete material consists of powder, graded fine aggregate, polymer, high-performance liquid accelerator, and water. The graded fine aggregate forms a riprap skeleton; the high-belite aluminum sulfate cement and silicate cement compound lay the foundation for rapid hardening; the modified hybrid fibers construct a three-dimensional reinforcing network to achieve high toughness and crack resistance; the multi-component composite expansion agent compensates for shrinkage throughout all ages; and the micro-nano active admixtures and polymer optimize interfacial bonding performance. It is complemented by high-pressure airflow cleaning / nano-silicon ion impregnation of the substrate and a three-phase distribution spraying method of rapid-hardening cement paste – graded fine aggregate – liquid accelerator. The concrete of this invention combines rapid hardening, high strength, and high toughness and crack resistance, shortening response time and improving construction efficiency.

The invention provides a multi-layer anti-corrosion non-prestressed anchor rod with a double-layer corrugated sleeve. The double-layer plastic corrugated sleeve is arranged on the periphery of an anchor rod body. The space between the inner-layer corrugated casing pipe and the anchor rod body and the space between the inner-layer corrugated casing pipe and the outer-layer corrugated casing pipe are filled with cement paste solidified bodies, and a centering support is arranged between the outer-layer corrugated casing pipe and the hole wall of the anchor rod and is filled with the cement paste solidified bodies; an anti-corrosion cap is arranged at the rear end of the outer-layer corrugated sleeve, a sealing ring is arranged between the anti-corrosion cap and the outer-layer corrugated sleeve, and a rear heat shrinkage sleeve is further sleeved outside the joint of the anti-corrosion cap and the outer-layer corrugated sleeve; the front end of the corrugated sleeve and an anchor rod body protruding out of the corrugated sleeve in the anchor rod hole are wrapped by the extension sleeve, and the corrugated sleeve and the extension sleeve are sealed through the sealing ring, so that the integrity of the anchor rod body is sealed. Multi-layer corrosion prevention of the non-prestressed anchor rod is achieved.

The application discloses a water-soluble polyurea early strength agent, a preparation method and application thereof. The method comprises the following steps: reacting diaminopolyether, diisocyanate and a catalyst to obtain a polyurea prepolymer; adding a chain extender into the polyurea prepolymer and continuously reacting to obtain polyurea; and finally, dropping the polyurea into water, continuously stirring in the dropping process, and obtaining a transparent water-soluble polyurea early strength agent. The water-soluble polyurea early strength agent is applied to cement paste, mortar and concrete mixing. The polyurea has abundant carboxyl sites, can be adsorbed on the surface of cement particles, prevents cement from condensing, improves the cohesiveness and water retention of the paste, and has better workability, can be uniformly dispersed and fully reacted in the concrete, so that the cement hydration is accelerated, and the early strength of the cement, mortar and concrete is improved.

The application relates to a device and a method for testing the bonding strength between a casing and well cement by using rotary torque, and belongs to the technical field of drilling material detection. The device comprises a test sample, a slip, a joint and a load applying device. Power is generated by a power device of a rotary dynamic torque tester to form rotary output, which drives a wellbore simulation casing to rotate. The wellbore simulation casing and a cement sheath fixed on a cementing cylinder are relatively displaced to form rotary torque. A torsion meter reads and records the torsion value when the cementing interface is damaged in real time, and the maximum value of the torsion value is taken as an index for representing the cementing strength. The device disclosed by the application is simple and convenient to operate, simple in structure, low in cost and reusable, and can be widely applied to the measurement and evaluation of the cementing performance of casings and well cement of different wellbore sizes.

The utility model discloses a self-proportioning lightweight concrete prevents residual and mixing device, including base, the top of base is provided with the sliding plate, one side of sliding plate is provided with the pivot, and one side of pivot is connected with the stirring bin, one side of stirring bin is provided with the scraper mechanism, and the other side of stirring bin is provided with the feed port, one side of feed port is provided with the dust cover, one side of dust cover is provided with the glue spraying mechanism, and the bottom of feed plate is connected with the reset piston, one side of reset piston is provided with the check valve, one side of check valve is provided with the foamed plastic warehouse, and the other side of check valve is connected with the stirring bin, and the cement paste is pushed reset piston through the oblique feed plate, and the resistance of buffer spring is overcome, and the vertical displacement is along the limiting groove, thereby opens the check valve, makes the foamed plastic enter the stirring bin from the foamed plastic warehouse, and this mechanical type trigger mechanism does not need external sensor or energy, realizes the automatic proportioning of foamed plastic and cement paste.

The utility model relates to the technical field of building wall construction, in particular to an aluminum alloy formwork screw hole plugging structure which comprises a block body in a circular truncated cone shape, and a plurality of containing grooves located on the same side are formed in the peripheral wall of the block body in the length direction of the block body. The surface of the block body is covered with cement paste, then the block body is inserted into the hole of the wall body, the cement paste is solidified, the block body is fixed in the hole, due to the fact that the multiple containing grooves are formed in the outer wall of the block body, the cement paste can be stored in the containing grooves, more cement paste can be stored, the adhesion degree of the cement paste is improved, and then the fixing effect of the block body in the hole is improved.

The invention belongs to the technical field of oilfield chemistry, and particularly relates to ultra-deep well high-temperature-resistant anti-channeling cement paste as well as a preparation method and application thereof. The ultra-deep well high-temperature-resistant anti-channeling cement paste comprises G-grade oil well cement, a high-temperature-resistant declining agent, a high-temperature fluid loss agent, a high-temperature retarder, a retarding auxiliary agent, a high-temperature stabilizer, an anti-gas-channeling agent, a defoaming agent and fresh water. The high-temperature-resistant anti-channeling cement paste for the ultra-deep well is suitable for well cementation at the high temperature of 90-210 DEG C and large temperature difference, the density is adjustable in the range of 1.85-1.95 g / cm < 3 >, the suspension stability is good under the high-temperature condition, the thickening time is adjustable, and the thickening time is easy to prolong.

The invention discloses a mortar fluidity evaluation model and a mix proportion inverse calculation method thereof, and belongs to the technical field of building materials.The method comprises the steps that aggregate comprehensive characteristic indexes are built by quantifying the stacking density, the specific surface area and grain shape correction parameters of aggregate; based on a cement paste volume balance principle, establishing a paste film thickness quantification model containing aggregate gap filling and surface wrapping; accurate evaluation of the fluidity is realized through a correlation model of the slurry film thickness and the mortar fluidity; and finally, based on the target fluidity, reversely deducing to obtain mortar mixing ratio parameters (water-cement ratio, mortar-sand ratio and the like) meeting the requirements. The method solves the problems that the traditional method cannot quantify the multi-feature coupling influence of the aggregate, the fluidity evaluation error is large, and the mix proportion design depends on experience, realizes the accurate prediction of the mortar fluidity and the efficient back-stepping of the mix proportion, is suitable for various aggregates such as natural sand, machine-made sand, shaping sand and the like, and provides a scientific basis for the mortar engineering application.

The application discloses a kind of building waste self-reinforced recycled aggregate preparation methods, comprising the following steps: (1), the building waste containing red brick and hardened cement paste is crushed, and red brick material and the block of hardened cement paste containing are separated out;(2), red brick material is mixed with the solution containing carboxyl ether and is ground, and the modified slurry containing nanoscale red brick particle material is obtained;(3), the block of hardened cement paste containing separated out is immersed in modified slurry, after immersion is completed, the block of hardened cement paste containing is taken out and is dried, and building waste self-reinforced recycled aggregate is obtained;In the solution containing carboxyl ether, solvent is water, and the concentration of carboxyl ether is 0.1-0.8mol / L;The particle size range of nanoscale red brick particle material is 50-200nm;During the process of immersion, the mixture is heated and stirred, and the heating temperature is 40-80 DEG C.The method can prepare building waste self-reinforced recycled aggregate with high strength and low water absorption.

The method comprises the following steps that firstly, drilling is conducted to a certain depth below a goaf bottom plate, reaming is conducted below the goaf bottom plate, a borehole is formed, a water stop ring is welded to a preset position of the outer wall of a sleeve, a water swelling filling layer is arranged below the water stop ring, and the water swelling filling layer is arranged below the water stop ring; a cement bolt is poured at the preset position of the inner wall of the sleeve, a grouting hole is formed in the section, corresponding to the sleeve, of the sandstone aquifer, the sleeve is put into a borehole, the water stop ring is located at the bottom of the sandstone aquifer, the grouting hole is located in the section of the sandstone aquifer, cement paste is injected through the sleeve, and the cement paste enters the annulus through the grouting hole and returns to the ground; in conclusion, the method has the advantages that the construction procedure is simplified, the construction efficiency is improved, grout leakage is avoided, the plugging effect is enhanced, the engineering cost is reduced, and the long-term stability is improved.

A liquid salt composition for a cementitious slurry, the liquid salt composition comprising one or more salts, one or more suspending aids, glycol, and water. The one or more salts are present in the

The utility model discloses a cement paste stirrer, which belongs to the technical field of stirring equipment and comprises a rack, a water storage bin and a cement storage bin are arranged at the top of the rack, a water metering scale is connected below the water storage bin and connected with a stirring barrel through a first feeding pipeline, and the cement storage bin is connected with the stirring barrel through a second feeding pipeline. A cement metering scale is connected to the lower portion of the cement storage bin and connected with the stirring barrel through a second feeding pipeline, a shock absorber is arranged on the second feeding pipeline, and a double-valve mechanism is arranged in the cement metering scale. The cement paste stirrer solves the technical problems that an existing cement paste stirrer is likely to have the material residue phenomenon, experimental errors are caused by vibration, and then the material weighing precision is affected.

The utility model relates to the technical field of constructional engineering, in particular to a high-strength cement paste stirring device which comprises a rack and a stirring mechanism, a lifting adjusting assembly is arranged on the rack, and the lifting adjusting assembly is provided with a lifting plate; a stirring pot is detachably arranged on the lifting plate; the stirring mechanism is provided with a driving assembly, the output end of the driving assembly is provided with a quick connector, the quick connector is detachably connected with the stirring blade, and the lower end of the stirring blade can extend into the stirring pot. In the embodiment of the utility model, through the detachable connection mode of the quick connector and the stirring blade, the stirring blade can be quickly detached and cement paste attached to the blade can be scraped into the pot in the pause interval process of the stirring test, and after the stirring test is completed, the stirring blade can be replaced by other components to clean the stirring pot, so that the stirring pot is convenient to clean. Through the structural design, attachments on the stirring blades can be quickly cleaned, and the device can be quickly cleaned.

The invention discloses a preparation method of spherical manganous-manganic oxide particles for well drilling or well cementation, which is characterized in that manganese nitrate and manganese acetate are compounded to realize the coupling of rapid oxidation and mild decomposition, effectively inhibit shell burst and hollow structure and improve the density and integrity of the particles; the introduced polyvinyl alcohol and citric acid can make the fog drop drying process more stable, and the problems of carbon residues and impure phases caused by a traditional surfactant are avoided. Furthermore, a three-stage spray pyrolysis method is adopted, stable evaporation, rapid phase formation and low-temperature curing of the solvent are achieved, and the problems of agglomeration, secondary sintering and insufficient crystal form development in the prior art are solved. The prepared spherical manganous-manganic oxide particles are concentrated in particle size, high in density and good in sphericity degree, can effectively reduce the viscosity of cement paste and reduce the settlement risk, have excellent suspension stability and flowability, are suitable for weighting requirements of high-density oil well cement paste and drilling fluid, and have wide application prospects in oil and gas drilling and well cementation.

The utility model provides a cement paste fluidity testing device. The cement paste fluidity testing device comprises a testing bracket, an inverted cone funnel, a valve, a top coupling beam, an indicator, a limiting nut, a level bubble and a paste collecting tray, the levelness is controlled by adjusting the adjusting nut on the test bracket, and the control precision of the test bracket in the horizontal and vertical directions is improved by assisting with the calibration of the level bubble and the counterweight small ball; meanwhile, the slurry collecting tray is hung at the bottom of the testing support to temporarily store waste slurry, so that slurry splashing and direct pollution to a site table board are avoided. The utility model relates to the field of neat paste flowability detection, and can obtain better technical and economic benefits when being applied to practical engineering.