13 results about "Free calcium" patented technology

The present application relates to solid waste resource utilization and carbon capture and utilization technical field, disclose a kind of using steelmaking waste gas to reduce the carbon sequestration treatment method of free calcium oxide of steel slag, comprising: steel slag, desulfurization gypsum, papermaking caustic white mud, waste building gypsum board powder and blast furnace water quenching slag are proportioned according to mass ratio, with mine acid wastewater to regulate alkaline slurry, into steelmaking waste gas and carry out wet carbonization disposal;During carbonization disposal, caustic white mud superfine particle is used as heterogeneous nucleation seed to accelerate f-CaO carbonization, three-way cascade supply guarantees uniform formation of ettringite, and mineral powder C-S-H gel is coated paper fiber and is converted into reinforcing phase;Carbonization product is obtained by pressure filtration dewatering and low-temperature drying.The present application realizes permanent mineralization and immobilization of steelmaking waste gas and efficient and complete digestion of f-CaO of steel slag, and multiple types of industrial solid waste and mine acid wastewater are disposed simultaneously, and the product can be used for mine filling and roadbed stabilizing material.

This invention provides a method for concentrating rare earth extract using a complexation-enhanced membrane. The method includes the following steps: (1) mixing the rare earth extract and a complexing agent, and adjusting the pH to obtain a pretreated solution; (2) performing membrane filtration on the pretreated solution to obtain a concentrated solution and a permeate; (3) adjusting the pH of the concentrated solution to obtain a concentrated rare earth solution; wherein the aqueous phase obtained from the extraction in step (3) is returned to step (1) for recycling. The method for concentrating rare earth extract using a complexation-enhanced membrane addresses the flux decay during nanofiltration concentration of rare earth-containing extracts. By adding a complexing agent to the extract, rare earth ions are complexed with calcium and magnesium ions. The complexing agent increases the effective size of rare earth ions, improving the retention rate of rare earth ions, reducing the concentration of free calcium and magnesium ions, reducing fouling on the membrane surface, and improving the membrane's operating efficiency.

This invention relates to the technical field of solid waste resource utilization, specifically to a highly active mineral admixture for multi-source solid waste, its preparation method and application, and a cementing material and its application. The invention involves calcining multi-source solid waste at above 1200℃ and then cooling it to below 150℃ within 1-2 hours to obtain a modified mineral admixture. The multi-source solid waste includes first electric furnace slag, steel slag, calcium carbide slag, and coal slag. Second electric furnace slag is mixed with a nitric acid solution, subjected to a hydrothermal reaction, and then separated into solid and liquid components. The resulting electric furnace slag leachate is mixed with a dispersant, the pH is adjusted to 11-13, and after a complexation reaction, it is dried to obtain a nanocrystalline nucleus material. The modified mineral admixture and the nanocrystalline nucleus material are mixed to obtain a highly active mineral admixture for multi-source solid waste. The highly active mineral admixture for multi-source solid waste prepared by this invention has a low free calcium oxide content, high volume stability, and high cementing activity, significantly improving the high-value-added resource utilization rate of solid wastes such as electric furnace slag and steel slag.

This invention discloses a method and system for online reconstruction of mineral phases in high-temperature steel slag, belonging to the field of steel slag resource utilization technology. The method involves crushing coal gangue and room-temperature steel slag to a particle size of 0.5 to 3 mm, mixing them at a mass ratio of 1:0.5 to 1.5 to prepare a reconstruction adjuster, and then adding the reconstruction adjuster and high-temperature liquid steel slag (temperature above 1350℃) to a mixing furnace at a mass ratio of 0.1 to 0.5:1. After settling, the mineral phase reconstruction is completed, converting free calcium oxide into dicalcium silicate and tricalcium silicate, magnesium oxide, ferrous oxide, and manganese oxide into the RO phase, and ferric oxide into ferrous oxide and elemental iron. The mixture after the reaction is cooled to below 500℃, then crushed, magnetically separated, and ground to a specific surface area of ​​400 square meters per kilogram to obtain a cementitious material. This invention utilizes the sensible heat of the high-temperature steel slag itself, eliminating the need for additional heating, achieving high-value utilization of solid waste. The prepared cementitious material exhibits high hydration activity and good volume stability. The process is simple and easy to implement, contributing to the metallurgical industry's achievement of dual-carbon goals.

The application discloses a carbonation method of free calcium oxide in steel slag and belongs to the field of iron and steel metallurgy. The steel slag is put into a reaction kettle, flue gas is introduced into the reaction kettle, the temperature of the flue gas and the CO2 concentration in the flue gas are controlled, proper amount of water vapor is introduced during the reaction, and proper amount of dust removal ash is added, so that the carbonation reaction is promoted to proceed in the positive reaction direction, and the free calcium oxide is quickly converted into stable CaCO3. The application can promote the carbonation reaction of the free calcium oxide (f-CaO) in the steel slag, quickly convert the free calcium oxide into stable CaCO3, improve the stability of the steel slag, expand the recycling range of the steel slag, and turn waste into treasure.

The application relates to the field of mine filling, in particular to preparation and application of carbon-mineralized phosphogypsum mine filling material, which is prepared from the following raw materials in parts by mass: 70-100 parts of red mud, 20-40 parts of yellow phosphorus slag, 1-10 parts of fly ash, 1-10 parts of slag, 5-20 parts of compound activator, 4-8 parts of modified cellulose, 10-30 parts of activated phosphogypsum, 8-16 parts of fine aggregate, 3-8 parts of modified biochar, 1-5 parts of water reducing agent and 50-100 parts of water; the modified cellulose is prepared from AlCl3, sodium hypophosphite, 1,4-butanediol diglycidyl ether and butane tetracarboxylic acid. In the high-alkaline environment, P and F are simultaneously and efficiently solidified, the fine aggregate cementing material is mixed into filling slurry, CO2 is introduced, free calcium oxide in the steel slag and calcium carbide slag is reacted with the calcium sulfate hemihydrate in the phosphogypsum to form calcium carbonate, the strength of the filling body is rapidly improved, and the solidification of CO2 is completed.

This invention relates to the field of road engineering, specifically to a process for constructing a road without a subbase using refined slag and converter slag. The process involves crushing converter slag as the skeleton aggregate and mixing it with refined slag as the fine aggregate. Pasteurella multocida inoculum solution and a cementing solution containing soluble calcium salts and urea are alternately sprayed into the mixture in stages and mixed. After paving, compaction, and curing, the mixture is covered and left to stand. Microbial metabolism generates calcium carbonate crystals in situ at the contact points between steel slag particles, forming a microscopic cementing network. This process, through in-situ mineralization and physical coating, blocks the contact between free calcium oxide and moisture inside the converter slag, eliminating local expansion stress caused by delayed hydration of free calcium oxide in the subbase structure, preventing the expansion and fracture of microcracks within the base layer, and cementing the steel slag mixture into a monolithic load-bearing slab.

The application discloses modified limestone powder and a preparation method and application thereof, and belongs to the technical field of building materials. The application provides a preparation method of modified limestone powder, and the preparation method comprises the following steps: mixing and grinding limestone raw materials and grinding aids. The grinding aids comprise sodium pyrophosphate, sodium gluconate, sodium citrate, an alcohol amine compound and water. According to the preparation method, the particle size of the obtained modified limestone powder can be effectively reduced, the sphericity of the modified limestone powder can be improved, and the content of free calcium ions in the modified limestone powder can be reduced. The application further provides the modified limestone powder prepared by the above preparation method and application of the obtained modified limestone powder.

The application discloses a kind of green low-carbon concrete based on steel slag and composite micro powder of slag and preparation method thereof, the concrete includes by mass fraction: 100 parts steel slag and blast furnace slag composite matrix;Controlled double-effect excitation system contains phosphate early strength precursor, sulfate excitation precursor and calcium ion chelation-buffer;And conventional accessories, when preparing, first water reducing agent and chelation buffer are dissolved in water to prepare bottom liquid, then add inorganic salt to prepare excitation solution, finally mixed with solid phase dry material and formed.The application introduces polyphosphate chelation buffer, uses the system alkalinity increase caused by free calcium oxide hydration as trigger condition, and constructs cascade reaction.The scheme guarantees the liquidity of construction at the same time, in-situ skeleton generation greatly improves early strength, and targets to consume free calcium oxide to eliminate late expansion hidden danger, generates in-situ gypsum to continuously excite slag, realizes the high unification of early strength and volume stability.

This invention discloses a mine backfill cementitious material and its preparation method. The mine backfill cementitious material of this invention comprises the following components in the following mass ratios: high belite sulfoaluminate cement clinker: 3-8 wt%; high free calcium silicate cement clinker: 1-3 wt%; granulated blast furnace slag powder or granulated blast furnace slag: 74-85 wt%; gypsum: 10-18 wt%. Compared with other paste-like backfill materials of the same strength, the cementitious material of this invention solves the problems of poor activation effect, poor mechanical properties affecting the mine backfilling effect, and high cost due to large amount of cementitious material used in existing mine backfill cementitious materials. At the same time, it not only reduces the proportion of cementitious material used, but also fully meets the requirements of mine backfilling projects.

The application discloses a method for calcining a concrete expanding agent by using a new dry-process kiln, which comprises the following steps: crushing and storing limestone, bauxite and hard gypsum respectively; taking the crushed limestone, bauxite and hard gypsum according to the mass percentage of 60-90wt%, 1-6wt% and 8-35wt% respectively, and then mixing and grinding to obtain a powdered material, i.e. raw material; pre-decomposing the mixed raw material by a preheater, and then feeding the pre-decomposed raw material into a rotary kiln for calcination; cooling the calcined raw material to obtain clinker of the concrete expanding agent; and grinding the clinker to obtain the concrete expanding agent. The method fully utilizes the advantages of the new dry-process kiln, so that the material is heated more uniformly, the calcination is more sufficient, the clinker of the expanding agent is uniform in size, the free calcium oxide content and the activity are stable, the structure is more compact, the activity of the free calcium oxide and the anhydrous calcium sulphoaluminate is more stable, and the comprehensive effect on the mechanical property of cement mortar and the limited expansion rate is better.

The application discloses a kind of cultivation methods for improving the salt stress resistance of seedling, belong to seed seedling cultivation technical field, comprising the following steps: S1, seed soaking treatment;S2, preparation of closure agent application liquid;S3, application closure agent application liquid;S4, preparation of mixed application liquid;S5, application mixed application liquid;S6, repeated application;The application is through the synergistic effect of modified polylysine calcium carbonate surface closure agent and modified pullulan calcium chelating agent to solve the problem that in the process of corn seedling transplanting and planting under the condition of carbonate type saline-alkali soil, exogenous silicon is fixed and inactivated by high concentration of free calcium ion in rhizosphere, the low survival rate of transplanting is caused by the insufficient salt stress resistance of seedling, and the problem of poor growth quality in seedling stage is solved, to realize the high-quality transplanting and planting and normal growth and development of corn seedling under the condition of carbonate type saline-alkali soil.

This invention relates to the field of building materials, specifically to a steel slag-based low-carbon ultra-high-performance concrete composite material and its preparation method. The composite material comprises, by weight, 30-50 parts mineralized steel slag powder, 20-30 parts cement, 10-15 parts silica fume, 5-10 parts fly ash, 1-3 parts water-reducing agent, 15-25 parts steel fiber, and 10-15 parts water. The mineralized steel slag powder is obtained by biochemical mineralization of steel slag powder through a mixture of alkaline bacterial solution containing Bacillus pasteurella and a calcium source substrate. A calcium carbonate crystal layer is deposited in situ on its surface, and residual bacterial protein adheres to the pores, forming a multi-scale stacked cementitious skeleton with silica fume and fly ash. The preparation includes mineralization, dry mixing, slurry preparation, fiber addition, and curing steps. This invention eliminates the free calcium oxide expansion source, preventing matrix cracking, fills the pores on the steel slag surface, and strengthens the interfacial bonding strength.