612 results about "Chromium oxide" patented technology

The invention relates to a modified chrome corundum ramming material and a preparation and construction process thereof, and belongs to the technical field of chrome corundum ramming materials. The ramming material comprises a material A, a material B and a material C, wherein the material A comprises chrome corundum aggregate, titanium dioxide coated aluminum oxide microspheres, calcium sulfide dehydrate and silicon carbide porous microspheres; the material B comprises chromium oxide-zirconium oxide composite nano powder, sodium thiosulfate pentahydrate, tricalcium phosphate and hexagonal boron nitride flaky crystals; and the material C comprises an aluminum dihydrogen phosphate-magnesium hydroxide compound, a calcium fluoride-aluminum oxide co-melt and a silane coupling agent. The preparation process comprises the steps of pretreatment of all the components, preparation of composite powder and layered preparation. The construction process comprises the steps of pretreatment, wet-process mixing, layered ramming, negative-pressure permeation, medium-temperature reaction, spraying curing, integral firing and the like. Generation of hexavalent chromium can be effectively inhibited, the thermal shock resistance, the mechanical strength and the heat-conducting property of the material are remarkably improved, and the material has the advantages of being good in environment friendliness, long in service life, excellent in construction performance and the like.

The invention discloses a selective separation and resource utilization method of chromium in a sodium vanadium solution, which comprises the following steps: S1, measuring a predetermined volume of sodium vanadium solution, and heating to a predetermined temperature; s2, a preset amount of divalent manganese salt is added into the sodium vanadium solution, so that hexavalent chromium is subjected to a reduction reaction; s3, after the reaction is finished, carrying out solid-liquid separation and washing to obtain chromium and vanadium removed liquid and precipitates; s4, vanadium precipitation and calcination are conducted on the chromium and vanadium removal liquid, and a vanadium oxide product is obtained; and calcining the precipitate at high temperature to obtain the chromium-manganese oxide. According to the method, the sodium vanadium solution is used as a raw material, the divalent manganese salt is used as a reducing agent, hexavalent chromium is reduced into trivalent chromium, the trivalent chromium generates chromium hydroxide precipitate under the alkaline condition, vanadium is not reduced and is reserved in the solution, and efficient separation of vanadium and chromium is achieved; the dechromed vanadium liquid is subjected to vanadium precipitation and calcination, and a vanadium oxide product is obtained; after the precipitate is subjected to high-temperature calcination, chromium-manganese oxide is obtained and can be used for preparing chromium-manganese alloy, and resource utilization is achieved.

The invention provides a method for preparing an iron-chromium electrolyte and electronic-grade ferrous chloride by using a stainless steel waste liquid. The method comprises the following steps: firstly, adding elemental iron and / or elemental chromium into the stainless steel waste liquid to obtain a chromium-containing ferrous chloride solution; then, sulfide is added, and nickel is removed; adding iron powder to increase the pH value to obtain chromium hydroxide precipitate and a ferrous chloride solution; dissolving chromic hydroxide in hydrochloric acid to obtain a chromic chloride solution; purifying the ferrous chloride solution to obtain an electronic-grade ferrous chloride crystal; and finally, adding a chromium chloride solution, the electronic-grade ferrous chloride crystal and hydrochloric acid according to a certain proportion, and stirring and mixing to obtain the iron-chromium electrolyte. The ferrous chloride prepared by the steps is relatively high in purity and less in waste; meanwhile, the prepared electrolyte is good in electrical property, low in attenuation rate and low in cost, the purpose of comprehensive recycling of resources is achieved, and the general trend of technical improvement is met.

The invention relates to a chromium-zirconium-corundum refractory material, a preparation method thereof and a chromium-zirconium-corundum brick. The chromium zirconium corundum refractory material comprises the following raw materials in parts by mass: synthetic chromium corundum powder, fused zirconium mullite powder, first chromium oxide powder, first alumina powder and a first binding agent; the synthetic chromium corundum powder comprises the following raw materials in parts by mass: second chromium oxide powder, second aluminum oxide powder and a second binding agent; the synthetic chrome corundum powder comprises first synthetic chrome corundum powder, second synthetic chrome corundum powder, third synthetic chrome corundum powder and fourth synthetic chrome corundum powder; the electric smelting zirconium mullite powder comprises first electric smelting zirconium mullite powder and second electric smelting zirconium mullite powder; the mass fraction of Cr2O3 in the chromium zirconium corundum refractory material is 30%-35%. The chromium zirconium corundum refractory material provided by the invention has the advantages of high porosity, high high-temperature structural strength, low high-temperature creep rate, strong chemical erosion resistance and good thermal shock resistance.

The invention discloses wear-resistant ceramic glaze water and a method for preparing a ceramic product, and relates to the technical field of ceramic products. The problems that in the prior art, mixing is not uniform, abrasion resistance is insufficient, adhesive force is poor, and production cost is high are solved. The prepared glaze water can form a compact and uniform glaze layer structure through reasonable proportioning of aluminum oxide, zirconium oxide and nano silicon dioxide, so that a ceramic product shows excellent wear resistance, the wear resistance coefficient of the ceramic product reaches 0.8 or above, and titanium oxide, chromic oxide and boric oxide are added, so that the high-temperature stability of a glaze layer is enhanced, and the service life of the ceramic product is prolonged. According to the invention, the glaze layer is not cracked, does not fall off and does not change color in complex environments such as high temperature, acid-base, impact and the like, the quality and appearance effect of the finished product are remarkably improved by matching with a segmented firing process, the performance of the ceramic product is improved, the stability and operability of production are also ensured, and the production cost is reduced. Wide application prospects are realized.

The invention relates to the field of electrochemical polishing of cobalt-based alloys, in particular to an environment-friendly electrochemical polishing solution of a cobalt-chromium-tungsten-nickel alloy and a polishing method of the environment-friendly electrochemical polishing solution. The cobalt-based alloy comprises the following chemical elements in percentage by mass: 15.0-25.0% of Cr; w: 10.0% to 20.0%; 0.0% to 15.0% of Ni; the balance is Co and unavoidable impurity elements such as O, N and H. The environment-friendly polishing solution comprises the following chemical components by mole percent: 0.5-2 mol / L of ChCl; 0.7 to 1.0 L of ethylene glycol; 0 to 0.3 L of ethanol; 0.1 to 0.3 L of glacial acetic acid; and a small amount of citric acid. According to the electrolytic polishing, alloy serves as an anode, a U-shaped titanium plate serves as a cathode, the voltage is 40-60 V, the current density is 0.5-2 A / cm < 2 >, and the polishing temperature is normal temperature. The method has the advantages that the environment-friendly electrolyte is adopted, the surface of the cobalt-chromium-tungsten-nickel alloy can be polished, pollution caused by electrolyte of a traditional chromium oxide system and an acid system is avoided, the follow-up repeated cleaning procedure is reduced, and material precision control is improved.

The invention relates to the field of refractory materials, in particular to a dry ramming mass for an intermediate frequency furnace and a preparation method thereof.The dry ramming mass is prepared from, by weight, 45-55 parts of fused corundum, 8-12 parts of fused magnesia, 15-20 parts of tabular corundum, 3-5 parts of fused spinel, 3-4 parts of activated aluminum oxide, 1-2 parts of silicon carbide, 1-2 parts of silica sol and 0.5-1 part of boric acid. 3.5-4.5 parts of a binding agent and 3-5 parts of an anti-penetrating agent; wherein the anti-penetrating agent is chromium oxide coated nickel aluminate microspheres. The invention solves the two major problems of easy penetration and thermal shock peeling of the traditional furnace lining, is especially suitable for harsh smelting environments of high manganese steel, stainless steel and the like, and has long service life and convenience in construction.

The invention relates to the technical field of alloy processing, and discloses a high-performance corrosion-resistant nickel-based alloy plate and a preparation method thereof, and the method comprises the following steps: raw material preparation, smelting treatment, casting treatment, hot rolling treatment, solution treatment, aging treatment and surface passivation treatment. According to the invention, when a composite acid system is adopted for passivation treatment, the concentration of chromium / molybdenum atoms in a passivation film is optimized and balanced due to the specific ratio of nitric acid to chromic acid, a chromium oxide provides a compact passivation barrier, and a molybdenum oxide endows the film layer with a self-repairing characteristic to synergistically inhibit pitting nucleation; meanwhile, nano titanium dioxide particles pretreated by silane are embedded into the passivation film in situ under the action of ultrasonic oscillation, organic pollutants adsorbed on a film layer can be decomposed by the photocatalytic characteristic of the nano titanium dioxide particles, the local corrosion effect of a battery caused by dirt coverage is avoided, and the performance of the battery is improved through double upgrading of components and the structure of the passivation film. And the alloy plate has excellent pitting corrosion resistance and fouling resistance in a chloride ion-containing medium.

The present invention relates to a preparation method of a self-propagating anti-corrosion and wear-resistant coating for a boiler water wall, belonging to the technical field of high-temperature protective coatings. The preparation steps are as follows: (1) Aluminum powder, iron(III) oxide powder, chromium oxide powder, zirconia fine powder, alumina fiber, heat-conducting filler and flux are ball-milled and mixed to obtain a mixed powder; (2) The mixed powder and sodium silicate binder are mixed evenly to obtain a suspension slurry; (3) The surface of the boiler water wall is treated by sandblasting; (4) A precoating is made on the surface of the boiler water wall; (5) A sodium silicate layer is made on the precoating; (6) A magnesium strip is ignited to initiate a self-propagating reaction to obtain a protective layer; (7) The protective layer is removed to obtain a self-propagating anti-corrosion and wear-resistant coating on the surface of the boiler water wall. The sodium silicate used as the binder obtains a dense self-propagating anti-corrosion and wear-resistant coating, and the self-propagating anti-corrosion and wear-resistant coating has good thermal conductivity, uniform thickness, excellent mechanical wear resistance and good corrosion resistance.

An optical component includes a substrate and an anti-reflective film. The substrate has an aspherical surface through which light passes. The anti-reflective film is disposed at least on the aspherical surface and includes a nanostructure layer and an intermediate layer. The nanostructure layer includes ridge-like protrusions that are non-directionally extended. A bottom of the ridge-like protrusions is closer to the substrate than a top of the ridge-like protrusions. The ridge-like protrusions gradually taper from the bottom toward the top. An average structural height of the ridge-like protrusions ranges from 108 to 368 nm. The intermediate layer is between the nanostructure layer and the substrate. A main component of the nanostructure layer is aluminum oxide. The nanostructure layer includes a metallic doping agent at least partially distributed inside the ridge-like protrusions. The metallic doping agent includes at least one of titanium, vanadium, chromium, titanium oxide, vanadium oxide, and chromium oxide.

Provided is a surface-treated steel sheet that can be produced without the use of hexavalent chromium and that combines excellent film corrosion resistance, coating corrosion resistance, film wet adhesion, coating secondary adhesion, and weldability. At least one side of the surface-treated steel sheet includes a Ni-containing layer, a metallic Cr layer on the Ni-containing layer, and an oxidized Cr layer on the metallic Cr layer. The water contact angle is 50° or less, and the total atomic ratio to Cr of K, Na, Mg, and Ca adsorbed on the surface is 5.0% or less.

The invention provides a black aluminum oxide ceramic material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing aluminum oxide, magnesium oxide, silicon dioxide, iron oxide, manganese oxide, chromium oxide and a solvent to obtain an aluminum oxide ceramic mixed solution; (2) mixing the alumina ceramic mixed solution with a binder, and grinding to obtain alumina ceramic powder; and (3) carrying out cold pressing treatment on the aluminum oxide ceramic powder, and carrying out vacuum pressureless sintering treatment to obtain the black aluminum oxide ceramic material. The black aluminum oxide ceramic material prepared by the method disclosed by the invention is relatively small in crystal grain, relatively small in pore and relatively high in density, and has relatively high compactness and thermal conductivity.

The invention provides a piston rod with a self-lubricating coating and a preparation method of the piston rod. The piston rod comprises a substrate and a chromic oxide layer which are arranged in a stacked mode. The chromic oxide layer comprises a chromic oxide inner layer and a chromic oxide film layer which are arranged in a stacked mode, the chromic oxide inner layer is located in the direction close to the substrate, and the density of the chromic oxide film layer is higher than that of the chromic oxide inner layer; the surface of the chromium oxide layer is provided with at least one pit, and each pit is filled with lubricating filler. According to the piston rod with the self-lubricating coating, the compact chromium oxide film layer has high corrosion resistance and abrasion resistance and can effectively block and isolate grease with corrosion property from immersing, and therefore it is guaranteed that the bonding strength of the chromium oxide layer and a substrate is not affected by corrosion factors; in addition, at least one pit is formed in the surface of the chromium oxide layer, the lubricating filler can be filled in the pit, a good lubricating effect is achieved, and therefore the lubricating performance of the piston rod is further improved.

The invention relates to the technical field of water-based propylene ink, and discloses high-stability water-based propylene ink and a preparation method thereof.The high-stability water-based propylene ink is prepared from, by mass, 30-35 parts of pigment, 10-15 parts of modified dispersing agent, 2-5 parts of modified nano chromic oxide, 1-2 parts of resin, 0.5-1 part of anti-settling agent and 40-50 parts of solvent. Acrylic resin formed by modified cellulose, acrylic acid and itaconic acid serves as a dispersing agent of the water-based propylene ink, the motion resistance of pigment sinking can be increased, the pigment sinking phenomenon is further prevented, and the stability of the water-based propylene ink is remarkably improved; the side chain of the acrylic resin can be adsorbed into the cavity structure of carboxymethyl-beta-cyclodextrin in the modified cellulose, so that the stability of the acrylic resin in the water-based propylene ink can be further enhanced, and the effect of preventing the pigment from settling can be better exerted; tannic acid in the modified nano chromic oxide contains a large number of hydrophobic benzene rings, so that the water resistance of the water-based propylene ink can be enhanced.

A main object of the present disclosure is to provide a reflection-type optical encoder scale capable of sufficiently reducing the reflectance on a low reflection region. The present disclosure achieves the object by providing a reflection-type optical encoder scale comprising a high reflection region and a low reflection region alternately placed on a substrate, wherein the low reflection region includes a low reflection portion including a metallic chromium film formed on the substrate, and a chromium oxide film and a chromium nitride film randomly formed on the metallic chromium film; and the high reflection region has higher reflectance of incident light from opposite side to the substrate of the reflection-type optical encoder scale, than the low reflection region.

The application discloses a kind of high-performance coiled material powder coating and preparation method thereof, belong to powder coating technical field, the application is by the compounding of organosilicon modified epoxy resin and carboxyl-terminated polyester resin, after organosilicon modification, the segment of introduction-Si-O-Si in system has high flexibility, and synergistic effect with nano calcium carbonate, it is helpful to balance the adhesion and flexibility of coating, grafting modification graphene oxide, active chromium oxide is added again, can obviously improve the mechanical strength of coating;After then, phosphite group is grafted onto graphene oxide, and is applied in the present powder coating system, can form three-dimensional network structure in system, chemical bond effect, not only can improve its crosslinking stability in system, and the sheet structure of graphene oxide, also can play certain barrier property, can also give coating longer weather resistance, and active chromium oxide synergistic effect is further improved, and the weather resistance and corrosion resistance of coating.

The invention discloses a method for co-producing benzoic acid and chromic hydroxide from methylbenzene and chromium-containing waste liquid. The method comprises the following steps: sequentially adding methylbenzene, a catalyst aqueous solution and an organic solvent into a reaction kettle; adding chromium-containing waste liquid to adjust the pH value of a reaction system in the reaction kettle; setting reaction temperature and reaction pressure, keeping the temperature for a certain time, and reacting; adding alkali liquor into the reaction liquid, adjusting the pH to be alkaline, filtering to obtain chromium hydroxide precipitate, and calcining chromium hydroxide to produce chromium oxide green; and adding an extracting agent into the filtrate, extracting and separating to obtain an organic phase, removing the organic solvent by using a rotary evaporator, and carrying out silica gel column chromatography to obtain benzoic acid. The characteristic that the chromium-containing waste liquid is acidic is utilized, the chromium-containing waste liquid is recycled, and the preparation method can improve the yield of chromium oxide green, reduce the usage amount of sulfuric acid and reduce the discharge of the chromium-containing waste liquid, and has important economic and environment-friendly significance.

The invention provides an application of a composite coating formed by titanium oxide and chromium oxide in hydrogen resistance, which comprises the following steps: substrate preparation: cutting a metal sample into a metal substrate, pretreating the surface of the metal substrate, polishing, cleaning and drying; cr2O3-10% TiO2 composite powder is adopted, the composite powder is heated to be in a molten or molten state, and under traction of plasma high-speed flame flow, the composite powder impacts the surface of the base body in an accelerated mode and deposits to form the ceramic coating. According to the application of the composite coating formed by the titanium oxide and the chromium oxide in hydrogen resistance, the hydrogen permeation current is reduced, so that the hydrogen resistance of the coating is enhanced.

The invention belongs to the field of coatings, and particularly relates to a preparation method of a wide-temperature-range wear-resistant protective coating of a metal sealing surface and the coating, and the method comprises the following steps: putting a pre-plated substrate into a plating solution with the Co < 2 + > concentration of 125g / L-155g / L, the ceramic particle concentration of chromium carbide particles and / or chromium oxide particles of 5g / L-15g / L and the hBN particle concentration of 1g / L-10 g / L, and electroplating under ultrasonic waves, the Dv50 values of the ceramic particles and the hBN particles are 2-8 [mu] m and 3-15 [mu] m respectively; the composite electroplating is divided into three stages, the ultrasonic frequencies of the three stages are 28-32 KHZ, 38-42 KHZ and 38-42 KHZ correspondingly, and the current densities of the three stages are 0.5-2 A / dm < 2 >, 1.5-3 A / dm < 2 > and 3-4 A / dm < 2 > correspondingly. The coating has significantly improved wear resistance and reduced surface roughness.

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 belongs to the technical field of EBSD sample preparation of heterogeneous materials, and particularly relates to an EBSD sample preparation method of an Al7075 / Al6061 bimetal composite cast ingot. According to the method, mechanical grinding and polishing and argon ion polishing are combined for EBSD sample preparation, during mechanical grinding and polishing, aluminum oxide polishing paste is selected for rough polishing, aluminum oxide or chromium oxide polishing paste is selected for fine polishing, and finally cerium oxide polishing paste is selected for fine polishing, so that crystal lattices with complete and distortionless sample surface layers are obtained as far as possible, and the defects such as trailing are reduced to the maximum extent; the optimal surface characteristics are provided for subsequent argon ion polishing, and meanwhile, the calibration rate of an Al7075 / Al6061 bimetal composite cast ingot EBSD sample prepared through the method is not lower than 90% in combination with the optimal argon ion polishing process parameters.

The invention provides a catalyst for synthesizing N-methylaniline and a preparation method thereof, the catalyst comprises an active component, a carrier and an auxiliary agent, the active component comprises oxygen-containing compounds of copper, zinc and chromium, the carrier is gamma-alumina subjected to surface hydroxylation treatment, and the auxiliary agent is a cerium-molybdenum bimetallic alloy. The preparation method comprises the following steps: loading the active component on the hydroxylation carrier through ultrasonic impregnation, drying, further loading the cerium-molybdenum auxiliary agent, and carrying out reduction alloying and roasting activation to form the composite catalyst. The catalyst is a regular cylinder, has the diameter of 4-6mm and the length of 4-6mm, has an optimized pore structure and surface properties, and is suitable for methylation reaction of aniline and methanol. According to the method, the dispersity of active components is improved through modified chromic oxide, the mass transfer efficiency is enhanced through a hydroxylation carrier, the synergistic catalysis effect of cerium-molybdenum alloy is combined, the reaction activity and selectivity are remarkably improved, meanwhile, side reactions are inhibited, the stability is enhanced, and the method can be widely applied to industrial production of N-methylaniline.

The invention discloses a high-performance coiled material powder coating and a preparation method thereof, and belongs to the technical field of powder paints.The high-performance coiled material powder coating has the advantages that organosilicon modified epoxy resin and carboxyl-terminated polyester resin are compounded, a-Si-O-Si-chain segment is introduced into a system after organosilicon modification, the flexibility is high, and the high-performance coiled material powder coating has a synergistic effect with nano calcium carbonate; the adhesive force and the flexibility of the coating are balanced, and the mechanical strength of the coating can be obviously improved by adding the grafted modified graphene oxide and the active chromic oxide; then, phosphite ester groups are grafted to the graphene oxide, the graphene oxide is applied to a powder coating system, a three-dimensional network structure and chemical bonding can be formed in the system, the crosslinking stability of the graphene oxide in the system can be improved, and a certain barrier property can be achieved due to the flaky structure of the graphene oxide; and the coating is endowed with long-acting weather resistance, and the weather resistance and the corrosion resistance of the coating are further improved through the synergistic effect with the active chromic oxide.

The invention relates to the technical field of fused alumina zirconia bricks, in particular to a fused alumina zirconia refractory brick and a preparation technology.The fused alumina zirconia refractory brick is prepared from, by weight, 55-65 parts of alumina powder, 25-35 parts of zircon sand, 1-5 parts of modified nanometer alumina powder, 2-6 parts of binder, 1-2 parts of chromic oxide, 1-3 parts of yttrium oxide and 1-4 parts of fluxing agent. Through in-situ growth of a layer of carbon nanotube core-shell structure on the surface of nano-alumina, the core-shell structure can prevent direct contact between nano-alumina particles, so that the possibility of nano-alumina agglomeration is reduced, and nano-alumina is uniformly distributed in the corundum amorphous refractory brick. A finer dispersed phase is formed in the brick body, so that the expansion of cracks is hindered, and the toughness and the strength of the brick body are improved.

The invention relates to the field of vanadium and chromium separation, and particularly discloses a sodium vanadium solution treatment method which comprises the following steps: S100, adding an alkaline reducing agent into a sodium vanadium solution, and carrying out reduction of hexavalent chromium and selective precipitation reaction of trivalent chromium; s200, at the later stage of the reaction in the step S100, urea is added into a solution system, and a deep removal reaction of silicon and chromium is carried out; and S300, after the reaction in the step S200 is finished, solid-liquid separation is conducted, silicon-chromium slag and purified vanadium liquid are obtained, silicon-chromium oxide is obtained after the silicon-chromium slag is treated and can be used for smelting silicon-chromium alloy, and the purified vanadium liquid is subsequently used for preparing a high-purity vanadium oxide product. According to the method, the vanadium sodium salt solution obtained through a vanadium slag sodium salt roasting-water leaching process is used as a raw material, hexavalent chromium in the solution is reduced through an alkaline reducing agent, selective precipitation separation of hexavalent chromium and vanadium is achieved, and meanwhile urea is supplemented to conduct synergistic precipitation removal on silicon in the solution.

The invention discloses a high-strength thermal shock resistant brick and a preparation method thereof. The high-strength thermal-shock-resistant brick is mainly composed of fused zirconia corundum with the particle size of 5-3 mm, fused zirconia corundum with the particle size of 3-1 mm, fused zirconia corundum with the particle size of 1-0 mm, fused zirconia mullite with the particle size of 3-1 mm, fused zirconia mullite with the particle size of 1-0 mm, fused zirconia mullite with the particle size smaller than or equal to 0.088 mm and fused chromic oxide with the particle size of 325 meshes. In addition, nano aluminum nitride powder and a binding agent are added. The preparation method comprises the following steps: firstly, carrying out dry mixing on granules, adding a binding agent into the obtained dry mixed material, stirring, carrying out wet grinding on the wet granular mixed material obtained after stirring, adding various powder materials in the wet grinding process, carrying out mixed grinding, and carrying out pressure forming on semi-dry plastic pug obtained after mixed grinding to obtain a green brick; and sequentially drying and firing the obtained brick blank to obtain the high-strength thermal-shock-resistant brick. The high-strength thermal shock resistant brick prepared by the invention not only has relatively high compressive strength, but also has excellent thermal shock resistance and erosion resistance, and can effectively prolong the service life when being applied to a colored intermittent smelting furnace and a discharge port.

The invention discloses a preparation method and application of a sodium-ion battery positive electrode material, and relates to the technical field of sodium-ion batteries, and the preparation method comprises the following steps: (1) dissolving a compound containing a Cr element in water, adding the solution into a reaction kettle, gradually dropwise adding a NaOH solution, after the reaction is completed, gradually adding a chitosan hydrochloride aqueous solution into the reaction kettle according to a certain ratio, and stirring to obtain a mixed solution; after reacting for a certain time, filtering, washing and drying to obtain chitosan-coated chromium hydroxide Cr (OH) 3 (at) CS; (2) blending the Cr (OH) 3 (at) CS prepared in the step (1) with a sodium source according to a certain molar ratio, sintering the mixture under protective gas, and then grinding and sieving to obtain a carbon-coated sodium chromite positive electrode material NaCrO2 (at) C; the sodium-ion battery has good electrochemical performance and cycle performance, and the sustainable development of the sodium-ion battery industry is promoted.

The invention discloses an H2 and CO erosion resistant Al2O3-Cr2O3 refractory material for a hydrogen-based shaft furnace and a preparation method of the H2 and CO erosion resistant Al2O3-Cr2O3 refractory material. The H2 and CO erosion resistant Al2O3-Cr2O3 refractory material comprises the following raw materials in parts by weight: 30-40 parts of chrome corundum particles with the particle size of 4-1mm; 10-15 parts of aluminum chromium slag particles with the particle size of 1-0 mm; 10-20 parts of fused brown aluminum oxide particles with the particle size of 3-1 mm; 20-30 parts of fused white corundum powder with the particle size of less than 0.074 mm; 5-10 parts of alumina micro powder with a particle size of less than 6 [mu] m; 3-5 parts of chromium oxide green with a particle size of less than 0.074 mm; 3-4 parts of phosphoric acid; and 3-10 parts of erbium oxide. The invention has good H2 and CO gas erosion resistance, slag corrosion resistance and stable high-temperature performance, and is convenient for construction and use, so that the overall service life of the hydrogen-based shaft furnace is prolonged.

The invention provides a high-performance rare earth composite calcium carbide furnace cover refractory castable and a preparation method thereof. The castable comprises the following raw materials in parts by weight: 100 parts of casting mixture, 0.5-3 parts of rare earth oxide, 0.1-0.2 parts of explosion-proof fiber, 0.1-0.3 parts of water reducer and 5-8 parts of water; wherein the casting mixture is composed of the following raw materials in parts by weight: 50-68 parts of brown corundum, 15-20 parts of mullite, 5-10 parts of aluminate cement, 4-7 parts of alumina micropowder, 4-6 parts of silicon oxide micropowder, 3-5 parts of clay additive, and 1-2 parts of chromium oxide green. The preparation method comprises: sieving brown corundum and mullite to the required particle size; weighing the above raw materials and their proportions, and then putting all the raw materials except water into a mixer and stirring for 10-20 minutes to fully mix the materials; after the materials are stirred evenly, slowly adding 5-8 parts of water and stirring until the castable is in a viscous state. The refractory castable provided by the invention improves the mechanical strength and thermal shock resistance of the furnace cover castable while ensuring that the furnace cover castable does not peel off or form a skin.

The invention provides self-recovery chromium ion doped oxide mechanoluminescence fluorescent powder as well as a preparation method and application thereof. The chemical general formula of the self-recovery mechanoluminescence fluorescent powder is Al2 (1-x) O3: 2xCr < 3 + >, wherein x is equal to 0.3%-5%. The preparation method of the self-recovery mechanoluminescence fluorescent powder comprises the following steps: a, respectively weighing aluminum oxide and chromium oxide according to the molar ratio of each element in the chemical general formula Al2 (1-x) O3: 2xCr < 3 + >; b, grinding and uniformly mixing the weighed raw materials, and firing in air at the temperature of 1300 DEG C for 6 hours; and c, taking out the fired sample, and uniformly grinding to obtain the chromium ion doped oxide mechanoluminescence fluorescent powder. According to the chromium ion doped oxide mechanoluminescence fluorescent powder disclosed by the invention, a measured emission band main peak is located at 694 nm and is located at a biological first window (600-900 nm), and the chromium ion doped oxide mechanoluminescence fluorescent powder is expected to be used as a near-infrared mechanoluminescence biological probe; and the fluorescent powder has the advantages of no need of pre-irradiation and instant self-recovery of luminescence.