41 results about "Directed crystallization" patented technology

The invention discloses an aluminum anodic oxidation electrolyte for improving the adhesion density of an electrode foil oxidation film, and relates to the technical field of anodic oxidation, the electrolyte comprises 3%-10% of ammonium dihydrogen phosphate, 0.5%-3% of sulfuric acid, 0.01%-0.2% of nano titanium dioxide or nano aluminum oxide, 0.05%-0.5% of an organic buffer agent, and the balance deionized water; the organic buffering agent is used for stabilizing the pH value in a range of 4.5-6.0; nano titanium dioxide or nano aluminum oxide is used as an oxidation film nucleation center to promote directional crystallization of gamma '-Al2O3; the sulfuric acid component improves the conductivity of the electrolyte; ammonium dihydrogen phosphate generates an aluminum phosphate barrier layer on the surface layer of the oxidation film to enhance the waterproof performance of the film layer; according to the electrolyte, the adhesion density and crystallinity of an oxidation film can be remarkably improved, the uniformity and waterproof performance of a film layer are improved, the specific volume stability and the formation efficiency are improved, and the electrolyte is suitable for continuous production of the high-performance aluminum electrolytic capacitor.

A hydrometallurgical process for recovering a plurality of metals from a complex rare and precious material, comprising the following steps: step 1: adding a complex rare and precious material to a hydrochloric acid solution, adding an oxidant for reaction, and then performing filtration to obtain a chlorination liquid and a chlorination residue; step 2: using two-stage counter-current gold loading to obtain a gold-loaded liquid and a post-loading liquid, reducing the gold-loaded liquid, performing clarification to obtain an organic phase, and filtering a precipitate to separate a post-reduction liquid and sponge gold; performing evaporation and concentration on the post-reduction liquid to produce a concentrate 1 and a condensate; and cooling and crystallizing the concentrate, performing filtration to obtain residual oxalic acid, and returning the residual oxalic acid to the reduction process and a post-crystallization liquid to gold loading; step 3: performing low-temperature distillation on the post-loading liquid to obtain a concentrate 2; step 4: performing high-temperature distillation on the concentrate 2 to obtain a concentrate 3; step 5: performing directional crystallization and centrifugal filtration on the concentrate 3 to obtain a crystallization residue and selenous acid; and step 6: washing the crystallization residue by using cold water or a low-acid-level condensate produced in step 3, and performing filtration to obtain a tellurium residue and a palladium-platinum-rhodium-rich liquid.

The invention belongs to the technical field of building materials, and particularly relates to a phosphogypsum-based cementing material additive based on an organic-inorganic composite oriented crystallization network, a cementing material and application. The porous adsorption-reaction agent, the superfine calcium sulfate whisker, the composite thickening time control agent, the organic polymer network agent, the interface reinforcing agent, the active filler and other components are used together, and a traditional alkaline excitation route is avoided through directional crystallization and an organic-inorganic composite network; the composite network obviously improves the mechanical property of the material and increases the softening coefficient; in addition, resource utilization of a large amount of industrial solid waste is achieved, energy is saved, carbon is reduced, the green sustainable development strategy is met, and an economical and feasible solution is provided for high-value and large-scale utilization of phosphogypsum.

The invention belongs to the technical field of ardealite resource utilization, and particularly relates to a method for recycling fluorapatite from ardealite leacheate through ion activity control. The method comprises the following steps: carrying out on-line detection on a fluorapatite saturation index on a phosphogypsum leacheate stock solution, and adjusting the supplementing amount of a Ca source / a P source / an F source in real time to keep a system supersaturated; adding background electrolyte, a complexing agent and a crystal face regulating agent into the treated solution to obtain a crystal precursor solution; controlling the temperature to be 50-90 DEG C, adjusting the pH value of the system to be 6.4-6.9, supplementing Ca < 2 + >, adding FA seed crystal, and uniformly stirring and mixing; the temperature is increased to 70-95 DEG C, the pH is increased to 6.8-7.8, a surface rearrangement accelerant is added for directional crystallization and solid-liquid separation, a solid product is washed and dried, and fluorapatite is obtained. FA crystal nucleation is controlled and regulated through ion activity, so that the yield and the purity of a target product are remarkably improved.

The invention discloses a self-adaptive magnetic field regulation and control magnetic control directional crystallization process in high-purity gallium production, which comprises the following steps: step 1, raw material pretreatment: putting a gallium raw material containing impurities into a smelting furnace, and heating to a temperature above a melting point, so that the gallium raw material is completely molten into liquid gallium; waste heat is recovered through a heat exchange device in the melting process and is used for preheating subsequent raw materials or other production links; 2, setting a self-adaptive magnetic field: transferring the liquid gallium into a crystallization container with a magnetic field generating device; step 3, accurate temperature control: arranging a plurality of coil heating units and water pipe cooling units outside the crystallization container, and arranging temperature sensors at different heights inside the crystallization container; step 4, crystal separation and post-treatment; the self-adaptive magnetic field regulation and control magnetic control directional crystallization process in high-purity gallium production can ensure the purity and quality of crystals through magnetic field regulation and control during use, can also effectively utilize the waste heat of equipment, reduces the production cost, and is suitable for popularization and application.

The invention belongs to the technical field of preparation of semiconductor crystal materials for high-performance radiation detection, and particularly relates to a preparation method of a low-twin-line tellurium-cadmium compound single crystal based on a moving heater method. Directional seed crystals with specific crystallographic orientation, an alloy material and a polycrystal feeding material are sequentially arranged in the growth container from bottom to top, the directional seed crystals and the polycrystal feeding material are both Cd1-xZnxTe, and the alloy material is composed of Te and Cd1-xZnxTe pre-dissolved in the Te; a moving heater method is adopted, an alloy material is melted in an axial gradient temperature field to form a melting zone, and the melting zone is driven to directionally migrate through relative movement of a growth container and the temperature field, so that Cd1-xZnxTe is directionally crystallized and grown on a seed crystal. The method can effectively inhibit the formation of twin crystal lines, obtains the tellurium-cadmium compound single crystal with a complete structure and uniform components, and can be industrially used in the fields of high-performance radiation detection, medical imaging and the like.

The invention relates to a method for rapidly growing a compact SiC single crystal at 1823K, and belongs to the technical field of semiconductor materials. The method comprises the following steps: pre-melting silicon, rare earth metal RE, a transition metal additive M and metal aluminum in a specific ratio into a Si-RE-Al-M alloy ingot by adopting an electric arc furnace under a micro-negative-pressure inert atmosphere; the pre-melted Si-RE-Al-M alloy ingot is placed in a graphite crucible or a silicon carbide ceramic crucible, under the specific temperature gradient condition, the temperature of the alloy ingot is increased to 1823 K through electromagnetic induction or resistance heating, the alloy ingot is melted again, heat preservation is conducted for 1 hour, and a Si-RE-Al-M-C solution with saturated SiC is obtained; under the same temperature gradient and inert atmosphere, the SiC seed crystal descends from the top of the solution at a specific rotation speed and is inserted into the SiC saturated Si-RE-Al-M-C liquid solution for growth of the SiC single crystal, and the block SiC single crystal is obtained; and adjusting the silicon-carbon ratio in the residual solution, and removing redundant carbon in the residual solution by adopting an electromagnetic directional crystallization technology, so that the residual solution is recycled and is used for growing the SiC single crystal again. According to the present invention, the rapid growth of the SiC single crystal at the low temperature of 1823 K can be achieved under the specific Si-RE-Al-M alloy ingot ratio, the solvent inclusion during the growth of the SiC single crystal through the solution method is inhibited, the compact high-quality block SiC single crystal is obtained, the residual solution for the growth of the SiC single crystal can be recovered, and the cost of the growth of the SiC single crystal through the liquid phase method is further reduced.

The invention discloses high-purity lithium borohydride and a preparation method thereof, and belongs to the technical field of inorganic synthesis.The preparation method comprises the steps that firstly, surface coordination activation is conducted on micron-sized lithium hydride through amino silane, and the reaction activity of the micron-sized lithium hydride is remarkably improved; and then, in a uniform ionic liquid organic solvent composite medium, efficiently synthesizing lithium borohydride with a purified borane complex at a mild temperature. For key impurity chloride ions, trimethylchlorosilane is innovatively introduced to carry out targeted precipitation conversion, and effective removal is carried out before crystallization. And finally, directly separating out a high-purity product from a reaction system through a directional crystallization technology. According to the high-purity lithium borohydride and the preparation method thereof disclosed by the invention, high-efficiency preparation of high-purity and low-chloride-ion lithium borohydride under a mild condition is realized, a key reagent can be recycled, and the problems of high energy consumption and insufficient purity in a traditional method are perfectly solved.

The application belongs to the technical field of polyethylene pipe materials, and particularly relates to a high-melt-hanging-resistance high-density polyethylene pipe material and a preparation method thereof. The polyethylene pipe material comprises: 80-95 parts by weight of high-density polyethylene resin, and 5-20 parts by weight of directional crystallization nucleating agent. The directional crystallization nucleating agent comprises 85wt%-95wt% one-dimensional nanomaterial and 5wt%-15wt% nano inorganic nucleating agent, based on the total amount of the directional crystallization nucleating agent. The modified polyethylene pipe material has improved zero shear viscosity and melt strength, and can be applied to large-diameter and thick-wall pipe material products.

The invention belongs to the technical field of optical crystal preparation, and provides a magnesium fluoride crucible descending type directional crystallization purification method for ultraviolet optical crystal manufacturing. Magnesium fluoride raw materials are placed in a vacuum furnace to be subjected to desorption pretreatment, then the raw materials are fused, subjected to heat preservation and homogenized, first-process directional crystallization is achieved through descending displacement of a crucible relative to a hot area, a first ingot body is obtained, impurities are enriched towards the tail end along with the crystallization process, and only a local section of the enriched end is heated and remelted to form a controlled molten pool; the middle-section main body is kept in a solid state; the temperature gradient direction is reversed by switching the power ratio of a heating area, the molten pool is subjected to second-process directional crystallization in the opposite direction to form a second ingot body, the second ingot body is axially cut in a segmented mode, a middle purification section is reserved to serve as a high-purity raw material, and the middle purification section can be repeatedly executed in the same furnace to obtain a raw material section; according to the method, segregation enrichment and reverse ending are completed in a clean atmosphere, and the method is suitable for manufacturing magnesium fluoride crystals for ultraviolet optical elements.

This invention proposes a method for preparing zinc sulfate heptahydrate through spatially induced directional crystallization via a zinc-substrate rolled structure. The method involves rolling zinc sheets into zinc coils, utilizing the geometric constraints between the zinc coil layers in conjunction with the high-speed shearing of the reaction liquid to guide seed crystals to grow along a specific direction, yielding high-purity, uniformly morphologically uniform ZnSO4·7H2O crystals. This method achieves ultra-low impurity residue while exhibiting breakthrough structural stability, with a product purity reaching 99.99%. Environmental testing shows that the material retains over 98% of its initial performance during long-term use, successfully solving the stability problems caused by lattice distortion, impurity residue, and industrial scale-up in traditional processes, providing a reliable guarantee for high-end material applications.

The application discloses a process for recovering multiple metals from complex rare and precious materials by a full-wet method, which comprises the following steps: step 1: adding the complex rare and precious materials into a hydrochloric acid solution, adding an oxidizing agent to react, and then filtering to obtain a chlorination liquid and a chlorination residue; step 2: adopting two-stage countercurrent gold loading to obtain a gold-loaded liquid and a post-loading liquid, reducing the gold-loaded liquid, clarifying an organic phase, and filtering a precipitate to separate a post-reduction liquid and sponge gold; the post-reduction liquid is evaporated and concentrated to produce concentrated liquid 1 and a condensate; the concentrated liquid is cooled and crystallized, and the residual oxalic acid is filtered out to return to the original process, and the post-crystallization liquid is returned to gold loading; step 3: low-temperature distillation of the post-loading liquid to obtain concentrated liquid 2; step 4: high-temperature distillation of the concentrated liquid 2 to obtain concentrated liquid 3; step 5: directional crystallization and centrifugal filtration of the concentrated liquid 3 to obtain crystallization residue and selenous acid; and step 6: washing and filtering of the crystallization residue by using cold water or the low-acid condensate produced in step 3 to obtain tellurium residue and a palladium-platinum-rhodium-rich liquid. The process provided by the application has the advantages of no waste water generation, a short process flow and high recovery rate of precious metals.

The invention discloses a preparation method of light self-repairing concrete, and relates to the technical field of concrete. The method comprises the following steps: firstly, efficiently packaging a calcium nitrate solution in hollow glass beads by utilizing a negative pressure impregnation technology; then growing a porous zeolite crystal coating on the surface of the microbead in situ by adopting a sol-gel method to form a self-repairing filler with a core-shell-hole gradient structure; when the concrete cracks to cause the breakage of the microbeads, the Ca in the cavity is quickly released, and the Ca adsorbed in the zeolite layer is gradually dissociated along with water permeation, so that the new microcracks are continuously repaired. Then, uniformly coating the surface and pores of the carboxymethyl cellulose hydrogel network with polydopamine in an in-situ oxidative polymerization manner to form composite hydrogel with photo-thermal responsiveness; lighting and heating to trigger dynamic coordination bond dissociation; meanwhile, heat drives rapid directional crystallization of a repair product by promoting the ion diffusion rate, and a compact mineralization layer is formed. The concrete prepared by the invention has the effects of light weight and self-repairing.

The invention relates to a top-down induced growth perovskite thin film, a method and a light emitting diode application, and the method comprises the following steps: coating a substrate with a perovskite precursor solution to form a perovskite wet film; and covering the perovskite wet film with a monocrystalline silicon wafer, carrying out stepped annealing, taking down the monocrystalline silicon wafer, and continuously annealing to obtain the perovskite thin film. According to the invention, the monocrystalline silicon wafer covers the perovskite wet film, stepped annealing is coupled, and the crystal orientation surface of the monocrystalline silicon wafer is in direct contact with the surface of the perovskite wet film, so that a directional crystallization physical environment from top to bottom is created, crystals are enabled to start from the upper surface of the film and extend downwards, bulk phase random nucleation is effectively inhibited, and the performance of the perovskite solar cell is improved. According to the preparation method disclosed by the invention, the preferred growth of crystals is promoted, the perovskite film which is consistent in crystal orientation height, compact, low in defect density and preferred in orientation can be prepared, and the photoluminescence external quantum efficiency of the perovskite film is comprehensively improved; when the material is applied to a light-emitting diode device, the device performance can be remarkably improved.

This invention discloses a selective separation and purification method for 2,4-dihydroxybenzoic acid based on a combination of boric acid complexation and directional crystallization, comprising the following steps: dissolving crude 2,4-dihydroxybenzoic acid containing isomers of 2,4-dihydroxybenzoic acid in a solvent; adding a phenylboronic acid derivative under stirring; adjusting the pH to 8.5–9.0; stirring and reacting at 45–70°C for 1–2 hours; filtering to obtain a first filtrate; concentrating the first filtrate by vacuum distillation; adjusting the pH of the concentrated solution to 2.0–3.0; performing programmed cooling crystallization from 50–78°C; filtering to obtain a second filter residue; and vacuum drying the second filter residue to obtain the product. The selective separation and purification method for 2,4-dihydroxybenzoic acid of this invention, through precise control of process parameters, can achieve a purity of 2,4-dihydroxybenzoic acid in the product exceeding 99.6%, a yield ≥86%, and an inorganic salt content <0.3%. Furthermore, it can form a closed-loop regeneration system to achieve efficient recovery and utilization of phenylboronic acid and the solvent.

The application discloses a kind of laboratory vanadium-containing waste liquid processing methods, belong to sewage treatment field.The specific steps include: waste liquid is concentrated after adding H2O2 reaction, adjust pH value and precipitate iron, chromium, titanium in turn, then generate NH4VO3 crystal and ammonium magnesium phosphate crystal by adjusting pH value and adding crystal seed, finally adjust pH value and distill ammonia water to prepare ammonium sulfate, residual liquid is evaporated to obtain Na2SO4.The application realizes the gradient recovery of vanadium, phosphorus and sodium elements by multistage pH control and directional crystallization process, the vanadium recovery rate of this method is >82%, the phosphorus recovery rate is >84%, which can effectively solve the technical problems of incomplete recovery of vanadium and phosphorus, non-resource utilization of valuable elements and non-compliance of waste liquid and waste gas environmental protection in existing laboratory vanadium-containing waste liquid treatment methods.

The invention discloses a directional crystallization process of a high-nickel ternary precursor in the technical field of inorganic functional materials, and the process comprises the following steps: dispersing a modifier in a base solution containing ammonia water in an inert atmosphere to form a suspension; the preparation method comprises the following steps: firstly carrying out explosive nucleation at a high feeding rate, converting into steady-state growth after a crystal nucleus reaches a target size, maintaining a constant acid-base value of a system by accurately controlling acid-base feeding, guiding metal hydroxide to radially and orderly deposit by utilizing a crystal face guiding effect of a modifier, and finally ageing, washing and drying to obtain the high-nickel ternary precursor. The modifier is prepared by the following steps: performing solvothermal synthesis, calcining under the protection of lithium carbonate atmosphere to obtain a cubic phase nano core, coating a titanium dioxide shell layer with low-temperature sol-gel, crystallizing, and finally treating and activating the surface by dilute ammonia water. The precursor prepared by the process has the advantages of uniform components, radial arrangement of primary particles, high sphericity and narrow particle size distribution, and the electrochemical performance of the precursor is effectively improved.

The invention belongs to the technical field of resource utilization of industrial by-products and preparation of inorganic functional materials, and discloses a method for preparing high-purity magnesium metavanadate based on synergistic conversion of the industrial by-products. Ammonium metavanadate extracted from a chlorination process titanium dioxide byproduct hydrochloric acid, a thermal power plant magnesium desulfurization byproduct magnesium sulfite and an aluminum oxide process is used as a raw material, and the method sequentially comprises the following steps: dissolving ammonium metavanadate in hot water, and acidifying with the byproduct hydrochloric acid to obtain an acidic vanadium-containing solution; adding a byproduct magnesium sulfite under heating and stirring, carrying out a deep impurity removal reaction, and carrying out solid-liquid separation to obtain a purified solution; adjusting the pH value of the purified liquid to be nearly neutral to initiate a synthetic reaction; directional crystallization is carried out by adopting programmed cooling and combining seed crystal induction; and separating, washing and drying to obtain the high-purity magnesium metavanadate. According to the method, synergistic high-value utilization of three industrial byproducts is achieved, the process is simple, the cost is low, the method is environmentally friendly, the purity of the obtained product is larger than or equal to 99.2%, the crystal form is regular, and the method is suitable for catalysts or electrode materials.

The application discloses a preparation method of lightweight self-repairing concrete and relates to the technical field of concrete. The application encapsulates calcium nitrate solution in hollow glass microbeads by using a negative pressure immersion technology; then, a porous zeolite crystal coating is grown on the surface of the microbeads by using a sol-gel method, thereby forming a self-repairing filler with a core-shell-hole gradient structure; when the concrete cracks, the microbeads are broken, Ca²+ in the cavity is quickly released, Ca²+ adsorbed in the zeolite layer is gradually dissociated with water penetration, and new microcracks are continuously repaired. Then, polydopamine is uniformly coated on the surface and in the pores of a carboxymethyl cellulose hydrogel network by in-situ oxidative polymerization, thereby forming a composite hydrogel with photothermal responsiveness; light heating triggers the dissociation of dynamic coordination bonds; meanwhile, heat drives the rapid directional crystallization of repair products by promoting the ion diffusion rate, thereby forming a dense mineralized layer. The prepared concrete has the effects of being lightweight and self-repairing.

The invention discloses a wastewater copper removal and resource recovery system and method based on a vulcanization induced crystallization fluidized bed, and belongs to the technical field of industrial wastewater treatment. The system comprises a pretreatment unit, a fluidized bed crystallization reactor and a solid-liquid separation unit, and is equipped with a vulcanizing agent accurate control system based on pH and ORP linkage. According to the method, the pH value of the wastewater is accurately regulated to 2.0-4.0 in a fluidized bed, a vulcanizing agent is added according to a stoichiometric ratio, and copper ions are induced to directionally crystallize on the surface of a fluidized seed crystal to generate copper sulfide. According to the technology, high-selectivity separation (coprecipitation rate lt: 5%) of copper to coexisting metals such as nickel and zinc is achieved by utilizing the extremely low solubility product of copper sulfide, traditional amorphous sludge is converted into high-grade (copper content gt: 45%) and low-water-content crystal particles which are directly used as copper smelting raw materials, the sludge reduction reaches 80% or above, and the problem of pollution control and pollution production in copper-containing wastewater treatment is solved.

The application provides an organic semiconductor longitudinal heterojunction monocrystal array and a preparation method thereof, and the preparation method comprises the following steps: providing a first silicon column template, a second silicon column template and a substrate; the first silicon column template and the second silicon column template are respectively provided with a first silicon column array and a second silicon column array, and the first silicon column template, the second silicon column template and the substrate are respectively provided with a first alignment mark, a second alignment mark and a third alignment mark; based on the melting point difference of different organic semiconductor systems, a longitudinal heterojunction monocrystal array with a determined crystal orientation and a controllable structure size is prepared through step-by-step melting, directional crystallization and alignment control. Compared with the traditional longitudinal heterojunction which is usually prepared layer by layer by using a solution method, the solvent is easy to damage the first layer of crystals when the second layer of crystals is formed, the step-by-step crystallization is realized by using the melting point difference in the application, the influence of the solvent on the first layer of crystals is avoided, and the application has the advantages of high controllability, good stability and strong applicability.

The invention belongs to the technical field of synthesis of rubber auxiliaries, and relates to a method for preparing high-crystal-form TMTD (tetramethylthiuram disulfide) through seed crystal induced hydrogen peroxide-chlorine step-by-step oxidation. Heating the sodium dimethyl dithiocarbamate solution, and then dropwise adding a hydrogen peroxide solution containing organic acid to generate TMTD microcrystals. Chlorine is slowly introduced into a system containing the seed crystal until the PH of the system is reduced to 1.0-2.0, and a reaction solution is obtained; and carrying out a neutralization reaction on the reaction liquid, directionally crystallizing, filtering, washing and drying to obtain a TMTD product. Through a step-by-step oxidation process, accurate control of the reaction process is realized, and side reactions are effectively inhibited. The in-situ generated TMTD microcrystal is used as a seed crystal, so that the crystal morphology and particle size distribution of a final product are remarkably improved. The whole process is mild in condition, simple to operate and suitable for industrial production.

The invention provides a crystallization defluorination method for fluorine-containing wastewater in the presence of high-concentration sulfate radicals, and belongs to the technical field of water treatment.The crystallization defluorination method comprises the following steps that before defluorination is conducted on fluorine-containing water containing the high-concentration sulfate radicals, lanthanum fluoride crystal seeds, a composite regulator and a defluorination agent lanthanum hydroxide are added into the water, crystallization reaction conditions are controlled, and the fluorine-containing water containing the high-concentration sulfate radicals is obtained. Enabling fluorine ions and lanthanum hydroxide to form a stable fluorine lanthanum compound crystal through directional crystallization; fluorine lanthanum compound crystals are removed through solid-liquid separation, and deep fluorine removal of the water body is achieved. According to the present invention, with the lanthanum hydroxide crystallization method, by using the extremely low solubility product of the fluorine lanthanum compound, the efficient fixation of the fluorine ions can still be achieved under the interference of the high-concentration sulfate radical, the fluorine concentration of the treated water body is stably reduced to less than 10 mg / L, the secondary pollution is avoided, and the defects of poor selectivity and easy saturation in the high sulfate radical environment of the traditional adsorption method are overcome; the method is suitable for treating high-salt fluorine-containing water bodies such as mining area wastewater and metallurgical fluorine-containing wastewater.

This application relates to a method for the disposal and recycling of gallium production waste, belonging to the field of metal recycling technology. The method includes: melting gallium production waste to obtain a gallium production waste melt, wherein the mass fraction of metallic gallium in the gallium production waste is greater than 95%; acid washing the gallium production waste melt to obtain pretreated gallium production waste; directional crystallizing the pretreated gallium production waste to obtain a solid crystalline phase with a purity ≥99.99wt% and an impurity-enriched liquid phase, wherein the difference between the cold and hot temperatures of the directional crystallization is 4℃~20℃; and alkaline dissolution treatment of the impurity-enriched liquid phase to obtain a gallium-containing solution. This application transforms gallium production waste into a reusable product through four sequentially linked steps.

The invention discloses a combined fluidized bed process system for recycling coal gasification grey water, which is integrated by a modular device. Comprising a wastewater collection tank module, a hardness-removing crystal fluidized bed reactor module, an ultra-clean biological fluidized bed reactor module, a biochemical regulation tank module, an ADFB anaerobic denitrification fluidized bed reactor module and an efficient sedimentation tank module which are sequentially connected through a pipeline, the hardness removal crystallization fluidized bed reactor module is integrated with a sodium carbonate and sodium hydroxide dosing unit; the biochemical regulation tank module is integrated with an acetic acid dosing unit; and a water outlet of the ADFB anaerobic denitrification fluidized bed reactor module is connected with a water inlet end of the wastewater collection pool module or the hardness-removal crystallization fluidized bed reactor module through a return pipeline provided with a control valve. According to the invention, efficient directional crystallization removal of calcium ions is realized through the hardness removal crystallization fluidized bed; cOD is rapidly degraded and efficient nitrification is completed by utilizing high-concentration immobilized microorganisms through an ultra-clean biological fluidized bed.

A full hydrometallurgical process for recovering metals from complex rare-precious material includes: adding the material to hydrochloric acid solution, adding oxidant, filtering to obtain chloride solution and chloride residue; using two-stage countercurrent gold loading to obtain gold-loaded solution and post-loading solution, reducing the gold-loaded solution, clarifying and filtering to separate organic phase, post-reduction solution and sponge gold; evaporating and concentrating the post-reduction solution to produce concentrated solution 1 and condensate, cooling and crystallizing the concentrated solution, returning filtered residual oxalic acid to reduction process, and returning post-crystallization solution to gold-loading process; low-temperature distilling the post-loading solution to obtain concentrated solution 2; high-temperature distilling the concentrated solution 2 to obtain concentrated solution 3; performing directional crystallization and centrifugal filtration on the concentrated solution 3 to obtain crystallized residue and selenious acid; and washing crystallized residue with cold water or low-acid condensate, and filtering to obtain tellurium residue and palladium-platinum-rhodium-rich solution.

The invention discloses a method for preparing high-purity potassium fluoborate by using byproduct fluosilicic acid, relates to the technical field of fine chemical engineering, and aims to solve the problems that impurity silicon is difficult to thoroughly remove, the product purity is limited, the raw material cost and the environmental protection pressure are high and the like when the potassium fluoborate is prepared by a traditional fluosilicic acid method. According to the method, by-product fluosilicic acid is taken as a raw material, and a multi-stage targeted silicon removal and purification control strategy is introduced, so that green and efficient preparation of high-purity potassium fluoborate is realized. The process comprises the steps of raw material pretreatment and compatibility, first-stage reaction and primary silicon removal, second-stage reaction and deep silicon removal, and third-stage reaction and directional crystallization. The methodology innovation is combined with the discovery of key parameters, so that the product purity can reach 99.7%, the content of key impurity silicon dioxide is lower than 0.02%, and meanwhile, the product yield is as high as 96.2%. According to the method, the product purity is remarkably improved, high-value utilization of byproduct resources is achieved, the production cost is reduced, and the method has the advantages of being environmentally friendly and high in safety.

The invention relates to the technical field of preparation methods of silicon carbide, in particular to a method for preparing electronic-grade silicon carbide through a coal ash dynamic impurity removal-gas phase purification method. The method comprises the following steps: pretreating a fly ash raw material with a KOH solution, carrying out acid leaching in an oxalic acid / citric acid mixed solution, introducing chlorine-containing gas to carry out gas-phase impurity removal, mixing with a biomass carbon source, carrying out heating reduction in a nitrogen-hydrogen mixed gas, introducing silicon steam, and carrying out a high-temperature reaction to obtain the high-purity beta-SiC. According to the process, presintering and a pore forming agent are not needed, and the limitation of a sandwich structure is broken through. According to the dynamic aluminum-silicon ratio feedback system based on viscosity real-time regulation and control, the problem of impurity regeneration caused by the fact that the aluminum-silicon ratio is difficult to precisely regulate and control in a coal ash hydrothermal melting method is effectively solved; the Cl gas phase deep impurity removal technology decomposes mullite into volatile chlorides under high pressure, and breaks through the acid leaching impurity removal limit; according to the silicon vapor partial pressure control model, generation of alpha-SiC is inhibited by accurately regulating and controlling the concentration of gas-phase SiO, and beta-phase oriented crystallization is achieved.

The invention relates to the technical field of crystal growth, in particular to a calcium fluoride crystal preparation device capable of preventing liquid level fluctuation and a growth process. The device comprises a bell jar, a crucible, a surrounding type movable heater, a detachable flow guide structure and a special connecting device, wherein a composite coating is arranged on the inner wall of the crucible to optimize the interface performance; according to the process, an atmosphere regulation and control mode combining vacuum pumping and discharging with inert gas protection is adopted, a step-by-step heating and cooling strategy is matched, and a stable temperature gradient is constructed through controllable movement of a heater. A temperature field adjusting mode that a crucible is static and a heater is movable is adopted, a detachable flow guide structure at an opening of the crucible and a stable growth environment of an inner wall composite coating are matched, and the process steps of vacuum pumping and discharging, inert gas protection and step-by-step heating and cooling are combined, so that directional crystallization of calcium fluoride melt is achieved; and mechanical vibration interference of a traditional Bridgman-Stockbarger method is avoided so as to improve the crystal quality.

The application discloses an aluminum anodic oxidation electrolyte for improving the oxide film adhesion density of an electrode foil, and relates to the technical field of anodic oxidation. The electrolyte comprises 3-10% of ammonium dihydrogen phosphate, 0.5-3% of sulfuric acid, 0.01-0.2% of nano titanium dioxide or nano aluminum oxide, 0.05-0.5% of an organic buffer, and the rest is deionized water. The organic buffer is used for stabilizing the pH value in the range of 4.5-6.0. The nano titanium dioxide or nano aluminum oxide serves as an oxide film nucleation center and promotes the directional crystallization of gamma'-Al2O3. The sulfuric acid component improves the electrolyte conductivity. The ammonium dihydrogen phosphate generates an aluminum phosphate barrier layer on the surface of the oxide film, thereby enhancing the waterproof performance of the film layer. The electrolyte can significantly improve the adhesion density and crystallinity of the oxide film, improve the uniformity and waterproof performance of the film layer, improve the specific capacity stability and formation efficiency, and is suitable for the continuous production of high-performance aluminum electrolytic capacitors.