75 results about "Chromium(III) oxide" patented technology

The invention belongs to the technical field of target material production, and discloses a ZMO target material which is prepared from zinc oxide, magnesium oxide and doped metal oxide. Wherein the doped metal oxide is selected from at least one of tantalum pentoxide, cerium dioxide, titanium dioxide, niobium pentoxide, manganese sesquioxide and chromium sesquioxide, the mass ratio of metal elements in zinc oxide to metal elements in magnesium oxide is (73-91): (9-27), and meanwhile, the metal elements in the doped metal oxide account for 1000-10000 ppm of the total mass of the metal elements in the target material. Through the design, on one hand, the relative density of the target material is improved, and on the other hand, higher carrier concentration or more excellent carrier migration capability is provided for the target material by doping the metal oxide, so that the resistivity of the target material is reduced; in addition, the invention also discloses a preparation method of the ZMO target material.

The invention provides near-infrared adjustable double-perovskite type mechanoluminescence fluorescent powder as well as a preparation method and application of the near-infrared adjustable double-perovskite type mechanoluminescence fluorescent powder. The expression general formula of the double perovskite type mechanoluminescence fluorescent powder is Sr2M1-xSbO6: xCr < 3 + >, wherein M is Al, Ga, Sc, In or Y; x is equal to 1%-7%. The preparation process of the fluorescent powder comprises the following steps: a, weighing strontium carbonate, an oxide of M, antimony pentoxide and chromium sesquioxide according to the element proportion in the chemical general formula Sr2M1-xSbO6: xCr < 3 + >; b, mixing the weighed raw materials, and uniformly grinding to obtain a mixture; and c, carrying out high-temperature calcination on the obtained mixture to obtain the near-infrared adjustable double perovskite type mechanoluminescence fluorescent powder. By regulating and controlling the components of the substrate, the emission main peak can be adjusted from 780nm to 946nm. The fluorescent powder provided by the invention can show a self-recovery near-infrared stress luminescence characteristic without pre-irradiation under continuous stress stimulation, is simple to prepare and convenient for industrial batch production, and has a wide application prospect.

The invention discloses a method for preparing high-purity chromium metal through carbon reduction, which comprises the following steps: proportioning chromic oxide, carbon powder, starch and water according to a certain proportion, and carrying out primary compaction to obtain a wet blank; adding the wet blank into an electric arc furnace, and smelting and melting to obtain bulk carbon chromium; after being manually and coarsely crushed, the molten and cooled large carbon chromium blocks are sequentially fed into a jaw crusher and a column mill to be crushed; adding chromic oxide, starch and water into the crushed carbon chromium, mixing, and carrying out secondary compaction to obtain a briquette-like material; feeding the coal-like spherical material into a drying box, gradually heating, fully drying a green body, and then cooling; and after drying, loading the blank into a vacuum reduction furnace layer by layer, and carrying out vacuum reduction on chromium sesquioxide and carbon chromium in a four-side heating manner to obtain the high-purity metal chromium. According to the method, preparation of high-purity metal chromium is achieved, and the conversion rate of preparing metal lattice powder from chromium oxide can be greatly increased; and the content of impurities in the metal chromium is reduced.

The invention relates to a method for preparing vanadium, chromium, aluminum and silicon products through gradient separation of vanadium shale. According to the technical scheme, silicon in the vanadium shale alkaline leaching solution is removed through a sulfuric acid precipitation method, and a desilicication solution and a siliceous precursor I are obtained; washing the siliceous precursor I with sulfuric acid, washing with water and calcining to obtain white carbon black; carrying out vanadium-chromium co-extraction on the desilicication liquid by adopting an amine extraction agent to obtain a vanadium-chromium organic phase; carrying out vanadium-aluminum extraction separation on the washing liquid by adopting an amine extraction agent to obtain a vanadium-rich organic phase and an aluminum-containing raffinate; the vanadium-rich organic phase and the vanadium-chromium organic phase are mixed, vanadium-chromium separation is achieved through step-by-step reverse extraction, and vanadium-rich liquid and chromium-rich liquid are obtained; adjusting the pH value of the aluminum-containing raffinate to precipitate aluminum hydroxide, and calcining to obtain aluminum oxide; carrying out ammonium salt vanadium precipitation on the vanadium-rich liquid to obtain ammonium polyvanadate, and calcining to obtain vanadium pentoxide; and reducing the chromium-rich liquid, adjusting the pH value, precipitating chromium hydroxide, and calcining to obtain chromium sesquioxide. The method is high in leaching rate, small in slag amount, high in product purity and high in recovery rate.

The invention discloses a low-toxicity cuprous oxide semiconductor coating material and a preparation method thereof, and in the composition of raw materials for preparing the low-toxicity cuprous oxide semiconductor coating material, copper oxide powder CuO and copper powder Cu are used as main components; at least two metal oxides are used as additives and at least comprise Cr2O3 and Fe2O3; kaolin, feldspar powder and quartz sand are used as mineralizing agents, and deionized water is used as a solvent; the raw materials comprise the following components in percentage by mass: 35-45% of copper oxide powder CuO; 8 to 12 percent of copper powder Cu; 7 to 9 percent of ferric oxide (Fe2O3); 7 to 9 percent of chromium sesquioxide (Cr2O3); 5% to 8% of feldspar powder 3Al2O3. 2SiO2-Al2O3; 18 to 22 percent of quartz sand SiO2; 5 to 7 percent of kaolin; the sum of the mass proportions of the components is 100%. According to the technical scheme, the problem that the existing semiconductor coating material taking Cu2O as a main material does not have the capability of adopting spraying processing due to the fact that Cu2O has high toxicity is solved.

The invention relates to the technical field of dyes, in particular to an acid black dye with green light and a preparation method thereof.The preparation method comprises the steps that a front color base I and a front color base II are synthesized firstly, then the front color base I and chromic oxide are complexed to obtain a reaction solution I, then the front color base II is added into the reaction solution I, and the acid black dye with the green light is prepared. The preparation method is simple and environment-friendly, a dye compound A, a dye compound B, a dye compound C and a dye compound D are formed by complexing a front color base I, a front color base II and chromium ions, and then the adding amount proportion of the front color base I, the front color base II and the chromium ions is adjusted; the ratio of the dye compound A to the dye compound B to the dye compound C to the dye compound D is adjusted, the green and full acid black dye is prepared, and the obtained acid black dye with green light is excellent in color fastness.

The present invention relates to a high-entropy rare earth chromate high-temperature negative temperature coefficient thermistor material, belonging to the field of semiconductor sensors, and aims to solve the existing perovskite structure high-temperature NTC material. Under high temperature environment, the Cr element in the system will volatilize in the form of gaseous CrO3, showing poor high-temperature aging stability. The high-temperature negative temperature coefficient thermistor material uses lanthanum trioxide, neodymium trioxide, samarium trioxide, europium trioxide, gadolinium trioxide and chromium trioxide as raw materials, and undergoes wet three-dimensional vibration ball milling, powder calcination, cold isostatic pressing, and high-temperature sintering to obtain a perovskite structure (La 0.2 Nd 0.2 Sm 0.2 Eu 0.2 G 0.2 )CrO3 thermosensitive material. The electrical performance parameters of this series of materials are: B 0℃ / 1300℃ =2044±1.42%K,ρ 1300℃ =1.45×10 3 ±1.73%Ω·cm. The high-entropy rare earth chromate high-temperature negative temperature coefficient thermistor (La 0.2 Nd 0.2 Sm 0.2 Eu 0.2 G 0.2 )CrO3 has excellent negative temperature coefficient characteristics in the temperature range of 0~1300℃, and shows good high temperature aging stability at high temperatures (the resistance drift rate is only 4.35% after aging for 500 hours at 1300℃).

This invention provides a high-entropy alloy nano-coating high-temperature oxidation-resistant modification preparation process, belonging to the field of coating modification technology. The high-entropy alloy nano-coating high-temperature oxidation-resistant modification preparation process specifically includes the following steps: S1. Target material selection and preparation; S2. Alloy substrate treatment; S3. Low-temperature nanocrystalline coating deposition; S4. Coating densification treatment; S5. Low-temperature recovery annealing; S6. Pre-oxidation treatment. Through the synergistic process of low-temperature preparation of the alloy nano-coating, densification annealing, and pre-oxidation, the high-temperature strength and phase stability of the coating are improved by utilizing the lattice distortion effect. A thermodynamically stable protective oxide film of aluminum oxide and chromium oxide is generated in situ on the surface, solving the problems of traditional chromium-based coatings such as few main components, poor oxidation resistance, and short lifespan. This significantly improves the service reliability and safety of nuclear reactor structural materials under high-temperature irradiation environments.

The invention relates to the field of refractory materials, in particular to a high-erosion-resistance refractory material based on boron nitride modification and a preparation method of the high-erosion-resistance refractory material. The problem that an existing refractory material is poor in erosion resistance is solved. The refractory material is prepared by taking zirconium dioxide, silicon dioxide, calcium oxide, ferric oxide and aluminum oxide as matrixes and adding samarium lanthanum magnesium aluminum composite gel powder and boron nitride loaded chromium sesquioxide, magnesium nitrate, aluminum nitrate, samarium nitrate, lanthanum nitrate and citric acid form gel, high-temperature treatment is performed to obtain the samarium lanthanum magnesium aluminum composite gel powder, and the samarium lanthanum magnesium aluminum composite gel powder is added to the boron nitride loaded chromium sesquioxide. Boron nitride is loaded with chromium sesquioxide after being treated by tannic acid, the corrosion resistance of the material is enhanced through the synergistic effect of all the components, and the material is suitable for high-temperature furnaces, high-temperature reactors and other industrial environments needing high-temperature resistance and high corrosion resistance.

The invention discloses a petuntse composition, ceramic and application, and relates to the technical field of ceramic. The ceramic disclosed by the invention is obtained by sequentially carrying out ageing treatment, sieving treatment, injection molding, airing, drying and sintering treatment on a petuntse composition. The petuntse composition comprises a ceramic waste material A, a ceramic waste material B and modified particles with gallium-coated cuprous oxide as a core and aluminum oxide as a shell in a specific proportion. And the components such as a high-entropy oxide solid solution generated by the reaction of hafnium oxide, tantalum pentoxide, niobium pentoxide, titanium dioxide, zirconium dioxide, chromium sesquioxide and carbon powder, and chromium heptacarbide are introduced, so that the ceramic prepared from the ceramic waste has excellent fracture toughness, bending strength, wear resistance, high temperature resistance and self-repairing ability. Therefore, the method has a wide application prospect.

The invention discloses a modified silicon carbide special ceramic material and a preparation method thereof, and belongs to the technical field of ceramic materials. The special ceramic material is prepared from the following raw materials in parts by weight: 80-100 parts of silicon carbide powder, 2-5 parts of chromic oxide, 5-10 parts of zirconium oxide, 3-8 parts of nickel oxide, 3-7 parts of boron nitride, 0.2-0.5 part of a binder and 1-4 parts of a lubricant. The special ceramic material prepared by the invention has relatively high hardness, excellent fracture toughness, extremely low density, wear resistance and extremely low thermal expansion coefficient, has a wide application prospect in practice, is simple in preparation method, and can be subjected to large-scale industrial production.

The invention discloses a nano coating with high radiation heat exchange capacity and a preparation method of the nano coating, and belongs to the technical field of nano coatings. Comprising 10 to 15 parts of cordierite micro powder, 4 to 8 parts of ferric oxide, 5 to 10 parts of silicon carbide, 5 to 10 parts of chromium sesquioxide, 3 to 8 parts of titanium dioxide, 5 to 10 parts of aluminum oxide, 1 to 5 parts of nickel oxide, 8 to 12 parts of self-made modified silicon dioxide mixed suspension, 18 to 28 parts of a composite binder, 0.4 to 1.2 parts of a dispersant, 0.1 to 0.2 part of an antifoaming agent, 0.3 to 0.5 part of a leveling agent and 12 to 22 parts of deionized water. According to the technical scheme, the self-made modified silicon dioxide mixed suspension is introduced into the nano coating, and an imidazole rigid group with relatively large steric hindrance is introduced into the modified silicon dioxide, so that the movement capability of each chain segment in the coating in a high-temperature environment can be reduced, and the temperature resistance of the coating is further improved.

The invention discloses a ferrochrome liquid decarburization method based on partial roasting and step-by-step vacuum, and belongs to the technical field of ferroalloy smelting. During operation, only part of ferrochrome raw materials and powder need to be ground into powder and roasted into the endogenous oxidizing agent mainly comprising chromic oxide; then, in a vacuum induction furnace, the blocky ferrochrome and part of the oxidizing agent are molten to form a liquid molten pool, the oxidizing agent reacts with carbon in the melt through the process of combining step-by-step stepped vacuumizing and adding of the remaining oxidizing agent in batches, generated CO is rapidly pumped away by a vacuum system, and therefore deep decarburization is achieved. The method effectively solves the technical bottlenecks that a traditional oxygen blowing method cannot produce micro-carbon ferrochrome, and a vacuum solid-state method is tedious in raw material treatment and too long in decarburization period.

The present application relates to a kind of gray glass composition and car window glass.The above-mentioned gray glass composition includes base component and coloring component, and the mass percentage of coloring component in gray glass composition is as follows: total iron Fe2O3 1.3%~2.5%, titanium dioxide TiO2 100ppm~800ppm, chromium trioxide Cr2O3 100ppm~500ppm, cobalt oxide CoO 100ppm~400ppm, selenium Se 10ppm~50ppm and tin oxide SnO2 10ppm~50ppm.The above-mentioned gray glass composition has the comprehensive performance of low visible light transmittance, low infrared transmittance, low ultraviolet transmittance, low solar direct transmittance, and also has the neutral gray tone that satisfies visual comfort, also has great economic advantage.

The application discloses a kind of microcrystalline glass and its preparation method, cover plate glass and electronic equipment, belong to new material field, the composition of this microcrystalline glass is: with mass percentage, SiO2 60~80%, Al2O3 1~10%, Li2O 10~18%, ZrO2 3~12%, Na2O 0~5%, CaO 0~4%, P2O5 1~5%, K2O 0~3%, Cr2O3 0~10%, Fe2O3 0~10%, Cr2O3, Fe2O3 Two are not simultaneously 0 and 1.9wt%≤Cr2O3+Fe2O3≤10wt%, it contains the crystal phase that produces gold star effect in its crystalline phase, produces gold star effect crystal phase is dichromium trioxide crystal, or iron oxide crystal, or chromite spinel, or dichromium trioxide crystal and chromite spinel.

The invention relates to the field of fused zirconia corundum bricks, and discloses a production method for regulating and controlling internal stress of fused zirconia corundum bricks, which comprises the following steps: preparing raw materials; melting in an electric furnace: putting the prepared raw materials into the electric furnace for melting; ventilating in stages in the melting process; preparing a mold for casting; after casting is completed, demolding and annealing are conducted; the raw materials comprise the following components in parts by weight: 50-65 parts of aluminum oxide; 25 to 35 parts of zirconium oxide; 8 to 12 parts of silicon dioxide; 0.5 to 2 parts of chromium sesquioxide; 0.5 to 1.5 parts of magnesium oxide; and 3-5 parts of scandium oxide. By adding scandium oxide and utilizing the characteristic that scandium oxide stabilizes a tetragonal phase, high-temperature phase change of zirconium oxide is effectively inhibited, and stress is reduced. Meanwhile, scandium oxide is used for refining grains, enhancing the grain boundary strength and reducing high-temperature stress concentration, so that the high-temperature stability of the fused zirconia corundum brick is improved, brittle fracture is avoided, and the thermal stability and durability are enhanced.

The present invention discloses a high-performance copper alloy for electronics and its preparation method, which relates to the technical field of electronic materials. In the present invention, copper alloy is modified by nano silver and nano tin. Under high-temperature conditions, the molten metals penetrate each other, fill the gaps between particles to make their connection tighter, thereby improving the electrical conductivity and mechanical properties of the matrix. Then, under the condition of high oxygen pressure, alloy powders mainly composed of aluminum, chromium, and tungsten carbide are melted and solidified through laser energy radiation to carry out metallurgical bonding with the matrix. First, a chromium trioxide oxide film is formed on the surface of the matrix, which reduces the oxygen activity at the oxide film interface, promotes the formation of a dense, complete and continuous aluminum oxide protective film by aluminum. Then, tungsten carbide therein forms a nucleation core, which refines the surrounding structure, improves the mechanical properties of the coating, and enhances the high-temperature oxidation resistance of the matrix.

The invention belongs to the technical field of solid waste recycling and wastewater treatment, and particularly relates to a method for treating chromium-containing wastewater by adopting organic amine flue gas desulfurization residues. According to the method, the organic amine flue gas desulfurization slag is adopted as a reducing agent, hexavalent chromium is reduced into trivalent chromium, the trivalent chromium is separated from water in a precipitate form, and the precipitate is roasted to obtain chromium sesquioxide powder with relatively high purity in supernate; hexavalent chromium and total chromium can reach the national standard. According to the method, the treatment cost of the hexavalent chromium wastewater and the flue gas desulfurization slag is remarkably reduced, and meanwhile, the resource utilization of the flue gas desulfurization waste in a waste-to-waste manner is also realized.

This invention discloses a ceramic clay composition, ceramics, and their applications, relating to the field of ceramic technology. The ceramics of this invention are obtained by sequentially processing the ceramic clay composition through a process of material conditioning, sieving, casting, air drying, oven drying, and sintering. The introduction of specific proportions of ceramic waste A and B, modified particles with a gallium-coated cuprous oxide core and an alumina shell, and high-entropy oxide solid solutions generated from the reaction of hafnium dioxide, tantalum pentoxide, niobium pentoxide, titanium dioxide, zirconium dioxide, chromium trioxide, and carbon powder, as well as chromium heptacarbonide, into the ceramic clay composition gives the ceramics prepared from the ceramic waste excellent fracture toughness, flexural strength, wear resistance, high-temperature resistance, and self-healing ability. Therefore, this invention has broad application prospects.

The invention relates to the technical field of hydrometallurgy, in particular to a vanadium and chromium separation method for a vanadium and chromium solution. The method comprises the following steps: adjusting the pH value of the vanadium-chromium solution to 2-4; adding a reducing agent into the vanadium-chromium solution; adding tetraalkylammonium into the obtained solution, stirring, and filtering to obtain a vanadium-containing precipitate and a chromium-containing solution; washing, drying and calcining the vanadium-containing precipitate to obtain vanadium pentoxide; adding alkali into the chromium-containing solution, stirring, filtering to obtain chromium hydroxide precipitate, washing, drying and calcining the chromium hydroxide precipitate to obtain chromium sesquioxide. According to the method, Cr (VI) is selectively reduced into Cr (III) through a reducing agent, vanadium in the solution exists in the form of polyvanadate anions and chromium exists in the form of Cr < 3 + >, then tetraalkylammonium is selected for vanadium precipitation, the radius of tetraalkylammonium ions is larger than that of NH4 < + > in a traditional vanadium precipitation agent, the tetraalkylammonium ions can be combined with the polyvanadate anions more easily to repel Cr < 3 + >, and therefore the vanadium precipitation effect is improved. Therefore, the separation of vanadium and chromium is simply, conveniently and efficiently completed.

The invention is applicable to the field of preparation of rare earth ceramic pigments, and provides a preparation method of a rare earth ceramic pigment for building wall surfaces, which comprises the following steps: S1, weighing industrial neodymium oxide and aluminum oxide in equal proportion, adding water, mixing and grinding to obtain slurry A; s2, weighing yttrium oxide and aluminum hydroxide in equal proportion, adding water and chromium sesquioxide, and mixing and grinding to obtain slurry B; s3, mixing the slurry A obtained in the step S1 and the slurry B obtained in the step S2 to obtain slurry C; and S4, the slurry C is poured into a drying cylinder to be dried, a stirring mechanism is arranged in the drying cylinder to stir and heat the slurry C, and a spiral conveying mechanism in the drying cylinder drives the slurry C to be vertically conveyed. The problems that in a traditional drying process, due to the fact that the conveying speed is not matched with the heating uniformity, the drying efficiency is low, and materials are heated unevenly are solved.

A welding flux for precipitation hardening (PH) stainless steel comprises 20-25 wt % of silicon dioxide (SiO2), 20-25 wt % of molybdenum trioxide (MoO3), 20-25 wt % of chromium (III) oxide (Cr2O3), 15-20 wt % of nickel (III) oxide (Ni2O3), 4-8 wt % of aluminum oxide (Al2O3), 4-8 wt % of aluminum nitride (AlN), 4-8 wt % of nickel (II) oxide (NiO) and 4-6 wt % of copper (II) oxide (CuO). By the use of the welding flux for PH stainless steel, together with the tungsten inert gas welding (TIG welding) procedure, a weld bead with a weld D / W ratio greater than or equal to 0.8 can be formed between the two PH stainless steel workpieces. Therefore, the welding flux for PH stainless steel is suitable for single-pass, full penetration welding of the PH stainless steel workpiece with a thickness greater than or equal to 3 mm.

The invention relates to the field of resistor discs, and particularly discloses a metal oxide resistor disc and a preparation process thereof, and the preparation process comprises the following steps: S1, mixing zinc oxide, antimony trioxide, chromium sesquioxide, manganese dioxide, aluminum nitrate and silver nitrate to prepare a slurry, adding a surface modifier, and mixing to prepare a mixed slurry; s2, drying the mixed slurry to obtain prefabricated powder, pre-sintering the prefabricated powder to obtain a pre-sintered mixture, grinding the pre-sintered mixture, and drying the ground pre-sintered mixture to obtain additive composite powder; s3, manganese carbonate, bismuth trioxide, nickel oxide and cobaltosic oxide are mixed to serve as an additive mixture, a tin dichloride solution is added, and a mixed solution to be deposited is prepared after stirring; s4, mixing the to-be-deposited mixed solution with an adhesive, absolute ethyl alcohol and additive composite powder, then drying, carrying out compression molding, and then carrying out calcination treatment; and S5, performing post-treatment to obtain the metal oxide resistor disc. The resistor disc has the advantages that the porosity of the resistor disc is reduced, the through-flow capacity is improved, and the electrical performance is improved.

The invention discloses a preparation method of a double perovskite oxide Sr2CrReO6 with high purity. According to the method, strontium carbonate and rhenium heptoxide are taken as raw materials and are subjected to high-temperature reaction under the protection of argon to synthesize an intermediate product; then mixing with chromium sesquioxide and elemental chromium powder, and carrying out high-temperature reaction under a vacuum tube sealing condition to obtain a crude product; and finally, carrying out heat treatment for multiple times in an inert atmosphere, and removing an impurity phase to obtain high-purity Sr2CrReO6 powder. By optimizing the temperature and time of the high-temperature reaction and introducing the heat treatment step, the impurity content is remarkably reduced, and the product purity is improved. According to the compact ceramic prepared from the high-purity powder through a spark plasma sintering technology, the antisite defect is 13.5%, the Curie temperature reaches 610 K, and the saturation magnetization is 0.84 microB / f.u. The method is easy and convenient to operate, low in equipment requirement, high in safety and suitable for laboratory-scale high-quality material preparation.

The invention discloses a high-entropy rare earth chromate negative temperature coefficient thermal sensitive ceramic material as well as a preparation method and application thereof, belongs to the field of high-temperature thermal sensitive sensors, and aims to solve the stability problem of chromium-based perovskite in high-temperature long-term use, especially the problem of electrical property reduction caused by Cr element volatilization. The thermal sensitive ceramic material with the negative temperature coefficient is prepared by the following steps: respectively mixing raw materials including lanthanum trioxide, neodymium oxide, samarium trioxide, europium oxide, gadolinium oxide and chromium sesquioxide with dysprosium oxide, holmium oxide, yttrium oxide and erbium oxide according to a stoichiometric ratio; and carrying out wet ball milling, drying, powder calcination, cold isostatic compaction and high-temperature sintering to obtain the perovskite structure (La1 / 6Nd1 / 6Sm1 / 6Eu1 / 6Gd1 / 6M1 / 6) CrO3 thermal sensitive ceramic material, and M is Dy, Ho, Y or Er. The electrical property parameters are as follows: B 25 DEG C / 1500 DEG C is equal to 1927-2011 K, rho 1500 DEG C is equal to 1.29 * 10 < 2 >-1.60 * 10 < 2 > omega.cm, and good high-temperature aging stability is shown at high temperature (the resistance drift rate after aging for 500 hours at 1500 DEG C is less than 4.6%).

The utility model discloses roasting equipment for producing chromium sesquioxide from chromium-containing waste, which comprises a support frame, a plurality of support legs arranged at the bottom end of the support frame, a chimney arranged in the middle of the support frame, a roasting furnace arranged at the bottom end of the chimney, a material conveying pipe arranged on one side of the roasting furnace, and a feeding hopper arranged at the other end of the material conveying pipe. A bin door is arranged at one end of the roasting furnace, an observation window is arranged in the middle of the bin door, an ignition gun is arranged on the other side of the roasting furnace, an exhaust port is formed in the top end of the chimney, and a filtering device is arranged at the top end of the exhaust port. An air inlet is formed in one side of the air chamber, a slag discharging opening is formed in the middle of the bottom end of the air chamber, a partition plate is arranged at the top end of the air chamber, and a plurality of filtering holes are formed in the surface of the partition plate. Through the arrangement of the air chamber, the air chamber is fixedly connected to the bottom end of the roasting furnace during use, and then sufficient oxygen is provided for the roasting furnace through the air inlet, so that substances in the roasting furnace are combusted more sufficiently, and the production rate of chromic oxide is further increased.

The present application relates to the technical field of preparation of oxygen reference electrode materials, and in particular to a method for optimizing the preparation process of oxygen reference electrode materials. It includes: obtaining the mass m1 of polyvinyl alcohol to be added, the mass m2 of chromium trioxide, the mass m3 of ferric oxide, and the mass m4 of chromium powder; inputting m1 into a first preset model to obtain the stirring speed v1 and the stirring duration t1 of the mixed solution after the chelating dispersant is added; inputting m1, m2, and m3 into a second preset model to obtain the speed e1 of adding chromium trioxide and ferric oxide to the modified solution and the stirring speed v2 of the modified solution after adding chromium trioxide and ferric oxide; inputting m1, m2, m3, and m4 into a third preset model to obtain the speed of adding chromium powder to the dispersed solution and the stirring speed of the dispersed solution after adding chromium powder; preparing oxygen reference electrode materials according to the dispersed solution. The present invention can improve the performance of the prepared oxygen reference electrode material.

The invention belongs to the technical field of preparation of nano metal ceramic composite powder, and particularly relates to superfine-grained thermal spraying powder and a preparation method thereof.The preparation method of the superfine-grained thermal spraying powder comprises the following steps that S1, a first carbon blending material and a second carbon blending material are obtained, the first carbon blending material comprises chromic oxide and carbon black, and the second carbon blending material comprises chromium oxide and carbon black; the second carbon blending material comprises nano tungsten powder and carbon black; s2, the first carbon blending material and the second carbon blending material are mixed and then subjected to high-temperature carbonization, and tungsten-chromium composite powder is obtained; s3, tungsten-chromium composite powder, cobalt powder, deionized water and a forming agent are mixed and then subjected to ball milling, spray drying granulation, sintering and crushing, and superfine nanocrystalline thermal spraying powder is obtained; in the process of preparing the tungsten-chromium composite powder, the addition of chromium can effectively inhibit the growth of tungsten carbide in the carbonization process of the nano tungsten powder, meanwhile, tungsten carbide can inhibit the growth of chromium / chromium carbide, and the tungsten carbide and the chromium / chromium carbide inhibit each other, so that the preparation of the ultrafine-grained powder is realized.

The invention relates to the field of electronic materials, and particularly discloses a low-gradient zinc oxide varistor and a preparation method thereof. The invention relates to a low-gradient zinc oxide piezoresistor disc, which is prepared from the following raw materials in parts by weight: 88 to 96 parts of zinc oxide, 1.5 to 3 parts of antimony trioxide, 2 to 5 parts of bismuth trioxide, 0.2 to 1.8 parts of nickel oxide, 0.1 to 0.9 part of cobalt sesquioxide, 0.1 to 0.4 part of manganese oxide, 0.02 to 0.07 part of chromium sesquioxide, 0.15 to 0.18 part of lithium acetate, 1.2 to 1.8 parts of dispersing agents, 1.8 to 2.5 parts of binding agents, 0.12 to 0.15 part of aluminum nitrate and 0.001 to 0.003 part of silver nitrate. Under the synergistic effect of all the components, by adjusting the use ratio of all the components, the potential gradient of the resistor disc can be reduced, the large-current endurance capacity of the resistor disc is improved, and the change of electrical performance after impact is reduced.