12 results about "Calcium Phosphate Crystals" patented technology

The invention discloses a grading reaction crystallization recovery process and system for semiconductor fluorine-containing and phosphorus-containing waste liquid, the fluorine-containing and phosphorus-containing waste liquid and a lime solution react in a fluorine recovery crystallization reactor under the condition that the pH is 3-4 to form calcium fluoride crystals, and the calcium fluoride crystals are dehydrated to obtain calcium fluoride particle crystal products; the effluent of the fluorine recovery crystallization reactor, the calcium fluoride crystal dehydration filtrate, the lime solution and the calcium chloride solution react in a secondary reaction tank under the condition that the pH is 5-6, and calcium fluoride, fluorapatite, silicon dioxide and silicon-aluminum precipitates are removed through coagulation, flocculation and precipitation; effluent of the second-stage reaction tank, the lime solution and the calcium chloride solution react in the phosphorus recovery crystallization reactor under the condition that the pH is 7-8 to generate hydroxyapatite crystals, and the hydroxyapatite crystals are dehydrated to obtain hydroxyl calcium phosphate particle crystal products. Meanwhile, a high-purity calcium fluoride crystal product and a hydroxyl calcium phosphate crystal product are produced, and fluorine and phosphorus are recycled.

A method for producing calcium phosphate crystals according to the present invention comprises a step (S11) for preparing a weakly basic phosphoric acid solution containing a complex comprising a rare earth element ion and a coordination compound having a ligand coordinated to the rare earth element ion and a step (S12) for adding a calcium-containing compound to the weakly basic phosphoric acid solution and hydrolyzing. Some of the plurality of calcium ions contained in the structure of the calcium phosphate crystals are substituted by the rare earth element ion.

The invention relates to the technical field of wastewater treatment and resource utilization, in particular to a process and a reaction device for preparing hydroxy calcium phosphate from phosphoric acid waste liquid. Under the condition of continuous stirring, a neutralizing reagent is conveyed into the crystallization reactor, and the conveying rate of the neutralizing reagent is regulated and controlled through a pH real-time monitoring feedback control system; after the pH value of the reaction system is stabilized at 9.0-11.0 and is continuously stabilized for several minutes, stopping conveying the neutralizing reagent into the crystallization reactor, and continuously stirring; and after the crystallization reaction is completed, carrying out solid-liquid separation treatment to obtain a filter cake and filtrate, discharging or recycling the filtrate, and carrying out post-treatment on the filter cake to obtain hydroxy calcium phosphate crystal powder. According to the process, the strong acidity of phosphoric acid and the strong alkalinity of lime are utilized to carry out a neutralization crystallization reaction, and the high-pollution phosphoric acid waste liquid is successfully converted into a hydroxy calcium phosphate product with a high added value, so that the hydroxy calcium phosphate product can be applied to the high-added-value fields such as biomedical materials and high-end fertilizers.

The present disclosure relates to a calcium phosphate coating that includes a plurality of nanometer sized calcium phosphate crystals that form a single layer. The coating is on a surface of a conductive substrate and is about 1 to 1000 nanometers thick, and greater than 25 percent of the coated surface area comprises the single layer of the crystals.

The invention discloses a method and device for improving phosphorus recovery of CaP crystals in sewage by using microbubbles, and the method comprises the following steps: adjusting the pH value of phosphorus-containing sewage to be alkaline, mixing the phosphorus-containing sewage with calcium salt, entering a nucleation reaction zone to obtain sewage containing calcium phosphate microcrystals, and enabling the sewage to flow into an air flotation zone after passing through a flow guide zone; high-pressure dissolved air water in the pressure dissolved air tank is pumped into a perforated pipe at the bottom of the air flotation area, and the perforated pipe releases the high-pressure dissolved air water to generate microbubbles; calcium phosphate microcrystals and microbubbles in the sewage in the air floatation area are flocculated into clusters and float upwards into the scum area; the calcium phosphate microcrystals in the scum area are agglomerated and cured under the shearing action caused by stirring and breaking of the microbubbles to obtain calcium phosphate crystals with the target particle size, and the calcium phosphate crystals are scraped into a scum tank by a scum scraper to realize phosphorus recovery; residual sewage after phosphorus recovery is discharged through a water outlet in the bottom of the air flotation area. The recovery method is simple to operate, and the recovered calcium phosphate crystals are controllable in particle size and high in recovery rate.

The application provides a stent weaving method and a stent woven by the method, the bending performance of the stent is better by improving the weaving method of the existing stent, adopting a spiral downward weaving method, and only one row of cross points between two rows of hook points. The application also improves the performance of the nickel-titanium shape memory alloy, the surface of the nickel-titanium shape memory alloy is coated with a calcium phosphate crystal film, and then a composite coating is coated, the microcrystalline layer of the application is uniformly distributed, the composite coating has high compatibility, and through the synergistic effect, the mechanical stability and the heat insulation effect of the nickel-titanium shape memory alloy are improved. The comprehensive performance of the stent prepared by improving the weaving method and the weaving material is significantly improved.

The application discloses a method for synchronously removing calcium and phosphorus in industrial circulating cooling water, which comprises the following steps: adding sodium bicarbonate into a solution containing calcium ions to which a scale inhibitor is added; passing oxygen into the solution so that the solution is in an oxygen saturation state; taking a carbon-based TiO2 electrode as a working electrode, a graphite electrode as a counter electrode, and a silver chloride standard electrode as a reference electrode, applying a voltage through an electrochemical workstation to electrochemically treat the solution, continuously passing oxygen in the whole process, and generating white precipitates in the solution after the reaction is completed; and realizing the synchronous removal of calcium and phosphorus by filtering and drying the white precipitates. The method can induce the release of calcium and phosphorus in the industrial circulating cooling water and induce the generation of calcium phosphate crystals, so that the synchronous Ca removal and P recovery are realized, and phosphorus fertilizer is provided for agricultural production. The method provides an environment-friendly and potentially economically valuable new idea for the repair of the industrial circulating cooling water.

This invention relates to the field of dental restoration technology, providing a glucose solution-stabilized calcium phosphate ion cluster, its preparation method, and its application. The invention utilizes a glucose solution to stabilize calcium phosphate ion clusters. In a high-concentration glucose aqueous solution, calcium ions and phosphate groups aggregate to form ion clusters. Upon contact with saliva, the glucose dissolves, releasing the calcium phosphate ion clusters, which then attach to the enamel prism structure of the tooth, triggering a mineralization reaction. This promotes the deposition and growth of calcium phosphate crystals along a specific orientation, restoring the original morphology of the tooth and improving the strength and hardness of the enamel. Furthermore, the glucose solution used in this invention stabilizes the calcium phosphate ion clusters, resulting in clusters with a size <2 nm, allowing them to penetrate nanoscale demineralization pores and easily penetrate enamel micropores. This results in high mineralization efficiency, high enamel restoration strength, and the mineralization process does not require high temperature, high pressure, or ultraviolet irradiation, exhibiting good biosafety and high clinical translation feasibility, thus possessing broad application prospects in the field of dental restoration.

The invention discloses a method for preparing flaky nano hydroxyl calcium phosphate in a clarification system by cooperating a compound additive with cavitation jet flow, which is characterized in that an SDBS / AEO9 / citrate ternary compound additive system is created for the first time, and oriented growth of hydroxyl calcium phosphate flaky crystals is realized through a molecular-level synergistic effect; an anionic sulfonic acid group of sodium dodecyl benzene sulfonate is specifically adsorbed to a 001 crystal face calcium site of HAP, growth in the c-axis direction is inhibited, and a crystal is forced to expand along an ab face to form a flaky element; through the synergistic effect of the three components, the contradiction that flaky HAP high diameter-thickness ratio growth and dispersion stability cannot be achieved at the same time is solved, a high-pressure cavitation jet flow technology is adopted in a breakthrough mode, and through the synergistic effect of cavitation bubble collapse microjet flow 300-1000 m / s and an instantaneous extreme physical field, crystal nanocrystallization crushing and flaky structure recombination are synchronously achieved; the ultrathin lamellar crystal with the average thickness is obtained on the premise that the crystallinity reaches up to 95.3%, and the energy consumption is reduced by 76% compared with that of a traditional process.

The invention belongs to the technical field of sewage treatment, and particularly relates to a method for removing phosphorus in sewage. The method for removing the phosphorus element in the sewage comprises the following steps: adding calcium phosphate seed crystals into the sewage, and mixing to crystallize and precipitate calcium phosphate. The method for removing the phosphorus element in the sewage has the beneficial effects that according to the method for removing the phosphorus element in the sewage, the calcium phosphate seed crystal is added into the sewage to be mixed, so that phosphate ions in the sewage reach a supersaturated state, and calcium phosphate is crystallized and then precipitated through continuous stirring and uniform mixing; the method is simple, remarkable in effect and low in cost.

The application relates to the technical field of tooth enamel repair, and discloses a tooth enamel remineralization repair gel based on bioactive glass, which comprises choline chloride, urea, anhydrous disodium hydrogen phosphate, anhydrous sodium citrate powder, 45S5 type bioactive glass, sodium alginate powder and urease freeze-dried powder. In preparation, the powder components are dispersed in anhydrous eutectic solvent synthesized by choline chloride and urea. The application cuts off the precipitation path of calcium ions in the storage period by using the anhydrous matrix, triggers in-situ crosslinking of sodium alginate and calcium ions to form a film after coating, and effectively resists fluid scouring. In the limited space formed by the gel, urea is catalyzed by urease to produce ammonia to promote nucleation, and meanwhile, the micronized citrate root preferentially dissolves and is adsorbed on the calcium phosphate crystal nucleus surface to guide directional crystallization. The application avoids disordered precipitation of calcium and phosphorus ions, and can reconstruct a dense biomimetic crystal column repair layer with excellent mechanical hardness on the demineralized tooth surface.

This invention discloses a calcium silicate-calcium phosphate crystalline phase composite material and its applications. The calcium silicate-calcium phosphate crystalline phase composite material is prepared by preparation method A or preparation method B. Preparation method A includes: obtaining a mixed system containing tetraethyl silicate, ethanol, and water; adjusting the pH of the mixed system to 1-2 with acid; adding calcium salt to obtain a first component; obtaining a mixed system containing phosphate, calcium salt, and water to obtain a second component; mixing the first and second components evenly, stirring at 50-80°C, drying at 110-130°C for 11-13 hours, sintering, cooling, mixing with ethanol, grinding, and sieving to obtain the calcium silicate-calcium phosphate crystalline phase composite material. This calcium silicate-calcium phosphate crystalline phase composite material is a milder active composition that can be applied in the fields of oral care, cosmetics, and skin and mucous membrane repair.