25 results about "Reactive magnesia" patented technology

The invention discloses a method for curing loess through titanium extraction tailing modified magnesium oxysulfate cement, and belongs to the field of civil engineering materials. The method comprises the following steps: weighing titanium extraction tailings, loess, magnesium oxysulfate cement and water according to a specific mass percentage, mixing and stirring the raw materials to form a solidified soil mixture, and carrying out compression molding, demolding and natural curing to obtain a solidified loess sample. Wherein the titanium extraction tailings are specifically treated industrial tailings, and the magnesium oxysulfate cement is formed by mixing active magnesium oxide and a magnesium sulfate solution according to a specific proportion. By optimizing the raw material ratio and the process, the mechanical property and durability such as water resistance and freeze-thaw resistance of the solidified soil are improved, meanwhile, resource utilization of the titanium extraction tailings is achieved, and the requirement for green and environment-friendly development is met.

The invention provides a reinforcing material suitable for a carbon sequestration rock interface and a preparation method thereof, and the preparation method comprises the following steps: calcining magnesium oxide powder to obtain active magnesium oxide; uniformly mixing active magnesium oxide with monopotassium phosphate to obtain first mixed powder; the molar ratio of the active magnesium oxide to the monopotassium phosphate is (3-5): 1; adding borax accounting for 5-10% of the mass of the active magnesium oxide into the first mixed powder, and uniformly mixing to obtain second mixed powder; mixing the second mixed powder with mixing water according to a water-material mass ratio of 0.10-0.40, and stirring to obtain magnesium phosphate cement paste; within the initial setting time after the magnesium phosphate cement paste is prepared, the paste is injected into a mold through pressure grouting equipment, and curing carbonization is conducted after the paste and rock are formed. By the adoption of the technical scheme, the interface sealing life is greatly prolonged, and the anti-carbonization performance is remarkably improved.

The application relates to the technical field of cement-based material admixtures, in particular to a magnesium oxide-based low-temperature expansion agent and a preparation method and application thereof. The magnesium oxide-based expansion agent prepared by using active magnesium oxide as a main component, using a small amount of calcium oxide, adding modified starch, aluminum sulfate and sodium carbonate as promoting components can be used for low-temperature construction of cement-based materials.

The present application relates to the technical field of highway construction, and particularly relates to a magnesium-based grouting reinforcement slurry mix proportion design method, wherein three kinds of slurry with different cement mixing ratios are configured in the slurry mix proportion design process, and 2-4% of active magnesium oxide curing agent is added to each of the three kinds of slurry to carry out a comparative test, and the final design quality mix proportion is determined through comparison of the results after 28d standard curing. The present application has the following advantages: the incorporation of active magnesium oxide promotes the hydration reaction of cement, improves the early strength of the composite foundation, and promotes the construction progress; the active magnesium oxide-cement composite slurry can significantly increase the cohesion and internal friction angle mechanical parameters of the composite foundation soil, improve the roadbed bearing capacity, reduce the overall settlement of the roadbed, and ensure the stability of the composite foundation; the magnesium hydroxide crystals generated by the hydration reaction of active magnesium oxide produce expansion to compensate for the shrinkage caused by the hardening of cement.

This invention discloses a retarder for magnesium silicate cementitious materials and its preparation and application methods, belonging to the field of green building materials technology. The retarder of this invention is composed of sodium hexametaphosphate, citric acid, and tartaric acid in a mass ratio of (1-3):(2-4):(0.5-2). The retarder of this invention forms a three-level gradient synergistic retarding effect by using sodium hexametaphosphate to inhibit the rapid dissolution of active magnesium oxide, citric acid to chelate and regulate the magnesium ion concentration in the liquid phase, and tartaric acid to inhibit the nucleation and growth of hydration products, covering the entire hydration process of magnesium silicate cementitious materials. This invention also discloses the preparation and application methods of this retarder. Compared with existing technologies, the retarder of this invention can significantly extend the setting time of magnesium silicate cementitious materials while maximizing the preservation of their mechanical properties and improving slurry fluidity. Furthermore, the raw materials are widely available, the preparation process is simple, and the cost is controllable, showing good prospects for industrial application.

The invention discloses a method for solidifying dredged sludge by using a biological carbonization active magnesium oxide technology, which comprises the following steps: uniformly mixing 4-7 parts of carbonized rice hull ash, 3-5 parts of active magnesium oxide and 5-8 parts of chitosan solution; and then adding 30-35 parts of modified filler, 3-5 parts of sodium lignin sulfonate, 10-15 parts of cement and 20-25 parts of water, and fully blending to obtain the curing agent. The curing agent is adopted for curing and dredging the sludge, carbonized rice hull ash and active magnesium oxide in the curing agent are matched with a chitosan solution, sodium lignosulphonate and cement, meanwhile, the modified filler is adopted for coordination and cooperation, and refilling liquid and an alpha-aluminum oxide agent in the modified filler are jointly matched for synergism, so that the curing effect of the sludge is improved. And the strength performance of the sludge in the system is optimized, and the product has excellent performance stability after being soaked in water and at high temperature.

The present invention proposes a method for characterizing the activity of light-burned magnesium oxide, comprising the following steps: calculating the active magnesium oxide content in the light-burned magnesium oxide; calculating the mass of the light-burned magnesium oxide based on the active magnesium oxide content; detecting the reaction time of the light-burned magnesium oxide with a weak acid; and obtaining a characterization result of the activity of the light-burned magnesium oxide based on the active magnesium oxide content and the reaction time. The present invention comprehensively considers the effective content of active magnesium oxide in the light-burned magnesium oxide and its reaction rate, characterizing both the amount of magnesium oxide that can participate in the hydration reaction and the speed of the magnesium oxide hydration reaction, thereby more comprehensively reflecting the activity characteristics of the light-burned magnesium oxide. The method of the present invention has a fast detection time and high accuracy, and is suitable for production; based on the characterization method of the present invention, the content of magnesium oxide participating in the hydration reaction can be accurately controlled, thereby achieving quality control of the light-burned magnesium oxide used in the preparation of magnesia cement and quality control of magnesia cement.

The application discloses a kind of water purifying agent waste residue-magnesium-aluminum ternary synergistic flow state solidified soil for bridge head backfill and preparation method, the flow state solidified soil includes: soil material, water purifying agent waste residue, aluminate cement, active magnesium oxide, magnesium sulfate heptahydrate, water-resistant modifier, reinforcing modifier and additional water.The application constructs water purifying agent waste residue-aluminate cement-magnesium sulphoaluminate cement three synergistic excitation mechanism, utilizes the chemical synergistic effect of aluminate cement and water purifying agent waste residue in magnesium sulphoaluminate cement environment, in combination with water-resistant modifier and reinforcing modifier, in situ induced magnesium-aluminum-calcium-based composite crystalline network.The network is inserted and wrapped in the interface transition zone between waste residue micro-particles and matrix, effectively repairs the crystal defects of traditional magnesium cement, significantly enhances the water resistance and chemical stability of the material, improves its strength retention rate in long-term immersion environment, ensures that backfill body has excellent long-term durability when bearing road load.

The systems and methods include a method. The method can include mixing, for a first time period, salt water with reactive magnesium oxide cement (RMC) at a first ratio to create a first mixture. The method can include mixing, for a second time period, the first mixture with an aggregate at a second ratio to create a second mixture. The method can include hydrating, for a third time period, the second mixture by molding and covering the second mixture. The method can include curing, for a fourth time period, the second mixture in a chamber to create an RMC-based composite, the chamber having a temperature value, a humidity value, and a CO2 concentration value.

The invention provides a low-shrinkage high-adhesion concrete crack repairing agent and a preparation method thereof, and relates to the field of concrete crack repairing, the low-shrinkage high-adhesion concrete crack repairing agent comprises inorganic dry powder and a microbial liquid agent, the mass ratio of the inorganic dry powder to the microbial liquid agent is 100: (20-30); wherein the inorganic dry powder comprises 60-75 parts of active magnesium oxide, 9-16 parts of monopotassium phosphate or ammonium dihydrogen phosphate, 10-20 parts of fly ash or silica fume and 5-15 parts of a boron compound; the microbial liquid agent is prepared from 10-25 parts of bacterial strain liquid, 1.2-3 parts of a nutrient source, 1.7-5 parts of a calcium source and 0-25 parts of distilled water; according to the invention, the induced mineralization ability of microorganisms is combined with the rapid hardening and early strength characteristics of an inorganic cementing material, so that the concrete crack repairing agent which has the characteristics of rapid plugging, high early strength, good cohesiveness, excellent environmental protection property and the like is developed.

The invention discloses a cementing material for a green low-carbon component and a preparation method, and relates to the technical field of green low-carbon building materials. The material comprises the following components in percentage by mass: 30-60% of a silicon-aluminum solid waste based gelling precursor, 3-12% of an alkaline activator, 5-20% of active magnesium oxide, 1-5% of a cationic biopolymer, 1-5% of an anionic biopolymer, a blending filler and water. The inorganic phase is composed of aluminosilicate gel formed by alkali excitation and a MgO carbonized product, and the organic phase is a complementary charged biopolymer composite network. The preparation method comprises the following steps: dry-mixing the powder, sequentially adding the alkaline excitation liquid and the cationic and anionic biopolymer solution, stirring to form slurry, and combining wet curing and CO2 curing after forming. The composite material has high strength, toughness, high temperature resistance, corrosion resistance and carbon sequestration performance, and is suitable for the fields of buildings, traffic and maritime work.

Disclosed in the present invention are a biochar-based alkali-activated containment material, a preparation method therefor, and the use thereof. The biochar-based alkali-activated containment material comprises 50-70% by mass of in-situ soil and 30-50% by mass of a cementitious material, wherein the cementitious material comprises an ash material and a composite alkali activator, and the composite alkali activator is obtained by ball milling activated magnesium oxide and biochar together. The biochar-based alkali-activated containment material of the present invention has better early compressive strength under a low cement-to-sand ratio and the 7d compressive strength thereof can reach 9.33 MPa; in addition, because of the presence of biochar, the containment material can better adsorb and trap soil contaminants and has better anti-seepage performance, and the permeability coefficient can reach 2.4×10-10 m / s. When being applied to rapid emergent containment for contaminated sites, the containment material can be quickly spread and quickly shape and achieve a lower seepage concentration of contaminants, thereby having a great application prospect.

The invention belongs to the technical field of building materials, and particularly relates to an active magnesium oxide-based carbon sequestration cementing material as well as a preparation method and application thereof. The active magnesium oxide-based carbon sequestration cementing material disclosed by the invention is prepared from the following mineral components: 5wt%-22wt% of periclase, 65wt%-80wt% of calcite and 0-5wt% of lime. The active magnesium oxide-based carbon sequestration cementing material contains active magnesium oxide, is good in carbonization activity, and can be used for preparing carbonized products with relatively high strength.

The invention relates to the technical field of refractory materials, in particular to a highly refractory RH gunning mix and a preparation method thereof. The high-fire-resistance RH gunning mix is prepared from the following raw materials in percentage by mass: 40-55% of graded 97 fused magnesite; 25 to 40 percent of graded high-purity sintered magnesia-calcium sand; 5-12% of active magnesium oxide; 2-5% of magnesium stearate; 3-8% of a binding agent; 0.5-2% of reinforcing fiber; 0.01 to 0.1 percent of explosion-proof fiber; wherein the binding agent is obtained by mixing the following raw materials in percentage by mass: 75-85% of modified starch and 5-15% of sodium hexametaphosphate; 5 to 15 percent of sodium carboxymethyl cellulose; the reinforced fibers are obtained by mixing modified carbon fibers and SiC whiskers according to the mass ratio of 9: (0.5-1). The RH gunning mix has excellent dispersibility, associativity, adhesiveness, erosion resistance and the like, the fire resistance of the RH gunning mix is enhanced through the comprehensive action, and the RH gunning mix shows longer service life.

The invention discloses a method for preparing magnesium oxysulfate cement by using high-activity magnesium oxide, and relates to a method for preparing the magnesium oxysulfate cement, which is characterized in that the hydration process of the high-activity magnesium oxide is regulated and controlled by adding a modifier, and the magnesium oxysulfate cement with good performance is prepared by controlling the feeding proportion of raw materials and process conditions. The invention aims to research and develop a preparation process of a green building material, and mainly aims to solve the problems of too short setting time, low mechanical strength, poorer water resistance and the like of magnesium oxysulfate cement prepared from high-activity magnesium oxide produced by new technologies such as flash light burning and the like due to too high content of the active magnesium oxide. The development of the high-activity magnesium oxide for preparing the environment-friendly magnesium oxysulfate cement is beneficial to expanding the wide application of the high-activity magnesium oxide, further promotes the popularization of a new technology for obtaining magnesium oxide such as flash light burning and the like, and provides a necessary technical support for energy conservation and carbon reduction of an industrial chain.

The invention relates to the technical field of building materials, and discloses an environment-friendly sand brick and a preparation method thereof.The environment-friendly sand brick is prepared from aggregate and raw materials of a gelling and functional system; the gelling and functional system comprises a sodium silicate solution, active magnesium oxide, glycerol triacetate and calcium formate; the preparation method comprises the following steps: carrying out dry mixing on the aggregate, the active magnesium oxide and the calcium formate, premixing a sodium silicate solution and glycerol triacetate, and then carrying out wet mixing, compression molding and maintenance. Sodium silicate gel is controlled by glycerol triacetate to provide early strength, and calcium formate is utilized to construct a substance transmission channel to drive active magnesium oxide to generate mineralization reaction in the later stage; an expansive product generated by the reaction can fill pores and microcracks, so that the long-term strength and water resistance of the material are remarkably improved, and damage self-repairing is realized; the sand brick prepared by the invention has excellent comprehensive mechanical property, durability and self-repairing function.

This application provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings and the magnesium-based cementitious materials themselves, relating to the field of mineral processing. The method includes: drying and first homogenizing phosphate rock flotation tailings, followed by calcination to obtain a first material; homogenizing the first material with activated magnesium oxide to obtain a second material; and mixing the second material with a conditioning agent to obtain a magnesium-based cementitious material; wherein the conditioning agent includes at least one of magnesium chloride and magnesium sulfate. The resulting novel magnesium-based cementitious material possesses excellent physicochemical properties such as short setting time and high compressive strength. Furthermore, the phosphorus-containing minerals remaining in the phosphate tailings can improve the water resistance of the magnesium-based material within the novel cementing system.

The invention relates to self-curing low-carbon concrete for flues and chimneys and a construction method of the self-curing low-carbon concrete for flues and chimneys, and the concrete comprises the following components in parts by mass: 270-290 parts of low-calcium clinker; 10 to 15 parts of lithium slag; 70 to 90 parts of mineral powder; 30 to 40 parts of monopotassium phosphate; 10 to 15 parts of active magnesium oxide; 10 to 15 parts of barium carbonate; 7-8 parts of a polycarboxylic acid water reducer; 0.5 to 1 part of boric acid and 0.5 to 1 part of a silane-based water repellent; 1.5 to 2.5 parts of polypropylene fiber; 120 to 130 parts of water; 800 to 900 parts of coarse aggregate; and 650 to 750 parts of fine aggregate. According to the invention, hydration of the low-calcium clinker can be effectively activated, and the early strength of concrete is improved; flue gas pollutants are cured in multiple modes such as active magnesium oxide and barium carbonate two-stage sulfur locking, and the concrete has the advantages of being fast in early strength development, excellent in sulfate corrosion resistance, low in carbon, environmentally friendly, high in pollutant curing capacity and the like.

The invention relates to a preparation method of active biological mortar, which comprises the following steps: S1, adding urea, a calcium source, corncob powder, L-cysteine, trehalose and nano-hydroxyapatite into a bacterial liquid of bacillus pasteurii, stirring and culturing, after crystals are completely precipitated, pouring out supernate, and centrifuging the remaining part to obtain active biological slurry with the water content of 42-28%; s2, premixing active magnesium oxide with 0.5-1% of monopotassium phosphate, and aging at 50-65 DEG C for 20-30 hours to obtain a reinforcing agent; the method comprises the following steps: pre-drying aeolian sandy soil and standard sand, mixing the aeolian sandy soil and the standard sand according to a mass ratio of 1: (1-3) to obtain mixed sand, and adding 2-5% of a reinforcing agent and 10-15% of waste ceramic micro powder into the mixed sand to obtain aggregate; s3, mixing the active biological slurry with the aggregate, and adding 0.2-0.5% of cellulose nanocrystals to obtain the active biological mortar which can replace cement mortar in a 3D printing cement mortar technology and is beneficial to energy conservation and emission reduction.

The present invention discloses a fully solid waste-based cementitious material using activated magnesium oxide to induce chloride salts from waste incineration fly ash and a preparation method thereof. The present invention uses activated magnesium oxide to induce the in-situ conversion of chloride salts from waste incineration fly ash into a cementitious material, effectively improving the instability of the solidification system and the potential secondary environmental pollution problems caused by the harmful impurity chloride salts, promoting the reaction degree and strength development of the cementitious system under the action of the coordinated disposal of copper-containing electroplating sludge, and ensuring that the heavy metal leaching concentration of the system complies with the national safe landfill standard GB / T 16889-2008. The cementitious material prepared by the present invention is expected to be used as a construction material such as roadbed, land leveling, and mine backfill, effectively broadening the way of value-added utilization of solid waste, while achieving efficient detoxification of waste incineration fly ash, having a positive impact on the environment, society and economy, and providing an innovative sustainable development model for the resource utilization of solid waste and the green transformation of the construction industry.

The invention provides a method for preparing a magnesium-based cementing material from collophanite flotation tailings and the magnesium-based cementing material, and relates to the field of mineral processing. The method comprises the following steps: calcining the collophanite flotation tailings after drying and first homogenization to obtain a first material; carrying out second homogenization on the first material and active magnesium oxide to obtain a second material; mixing the second material with a conditioning agent to obtain a magnesium-based cementing material; the conditioning agent comprises at least one of magnesium chloride and magnesium sulfate. The prepared novel magnesium-based cementing material has excellent physical and chemical properties such as short setting time and high compressive strength, and meanwhile, residual phosphorus-containing minerals in the phosphate tailings can play a role in improving the water resistance of the magnesium-based material in a novel cementing system.

The invention discloses a quick-setting high-viscosity high-strength road cold patch material, which is prepared from the following ingredients in parts by weight: 40 to 50 parts of sulphoaluminate cement, 20 to 30 parts of modified slag, 4 to 6 parts of active magnesium oxide, 2 to 4 parts of slaked lime, 2 to 3 parts of EVA latex powder, 1 to 2 parts of nanometer silicon dioxide, 20 to 40 parts of basalt, 15 to 25 parts of quartz sand, 0.8 to 1.2 parts of polycarboxylic acid water reducing agents and 0.3 to 0.5 part of boric acid retarders. The preparation method comprises the following steps: S1, preliminarily pre-mixing the EVA latex powder and the quartz sand, the modified slag and the nano silicon dioxide, and the sulphoaluminate cement and the boric acid retarder in proportion respectively; s2, adding basalt, the three premixes, active magnesium oxide and slaked lime into a stirrer in proportion, and stirring step by step to obtain a dry mixture; s3, dissolving a polycarboxylic acid water reducer and water in proportion to obtain mixing water, adding the mixing water into the dry mixture, and stirring to obtain a finished product. The prepared quick-setting high-viscosity high-strength road cold patch material is short in initial setting time and high in compressive strength and bonding strength.

The application relates to a preparation method of active biological mortar, and comprises the following steps: S1, urea, a calcium source, corncob powder, L-cysteine, trehalose and nano-hydroxyapatite are added into bacterial liquid of bacillus pasteurii, and stirring culture is carried out; after complete crystallization and precipitation, supernatant is poured out, and the remaining part is centrifuged to obtain active biological slurry with a water content of 42-28%; S2, active magnesium oxide is premixed with 0.5-1% potassium dihydrogen phosphate, and is aged at 50-65 DEG C for 20-30h to obtain an enhancer; after standard sand and wind-sand soil are pre-dried, the two are mixed according to a mass ratio of 1:1-3 to obtain mixed sand; 2-5% of the enhancer and 10-15% of waste ceramic powder are added into the mixed sand to obtain aggregate; S3, the active biological slurry and the aggregate are mixed, and 0.2-0.5% of cellulose nanocrystals are added to obtain active biological mortar, which can replace cement mortar in 3D printing cement mortar technology, and is beneficial to energy saving and emission reduction.

The invention relates to the technical field of cement-based material admixtures, in particular to a magnesium oxide-based low-temperature expanding agent and a preparation method and application thereof. Active magnesium oxide is adopted as a main component, a small amount of calcium oxide is used in cooperation, and modified starch, aluminum sulfate and sodium carbonate are added as promoting components; the magnesium oxide-based expanding agent can be used for low-temperature construction of cement-based materials.