344 results about "Chromate and dichromate" patented technology

The present invention relates to the technical field of providing corrosion resistant coatings or anticorrosion coatings on substrates which are susceptible to corrosion, particularly on metallic substrates, especially of providing chromate-free corrosion resistant (anticorrosion) coatings on such substrates.

The invention belongs to the technical field of chemical materials, and relates to a treating fluid and a method for preparing vanadium-zirconium composite conversion coatings with self-repairing performance on aluminum alloy surfaces through the same. The method includes the steps of firstly preparing the treating fluid containing fluorozirconate, metavanadate, sodium fluoride, nitrate, an accelerate and an additive; then putting an aluminum alloy after surface pretreatment into a working fluid made of the diluted treating fluid for 2min-10min; and finally subjecting the aluminum alloy to washing, drying and cooling to obtain the vanadium-zirconium composite conversion coatings. The preparation process is simple, heavy metals such as hexavalent chromium and nickel are not contained, the environment is friendly, the conversion coatings of the aluminum alloy after a conversion coating treatment are dense and high in binding force, metal ions in the conversion coatings can bond with base metal under a corrosion environment and provided with a certain self-repairing performance, and the treating technology of vanadium-zirconium conversion coatings can effectively replace chromate treatment on aluminum alloy surfaces.

A method for extracting vanadium and chromium from materials containing the vanadium or/and the chromium is characterized by comprising the following steps: taking salt and alkali of alkali metal or the alkali of the alkali metal as an oxidation transformation medium of the materials containing the vanadium or/and the chromium; carrying out treating for 0.5-6 hours at the temperature of 160-600 DEG C under the effect of an oxidizing agent and enabling the vanadium and the chromium in the materials to be converted into soluble vanadate and soluble chromate; carrying out water leaching to obtain leaching liquor containing the vanadium or/and the chromium; adding a precipitant A in the leaching liquor containing the vanadium or/and the chromium to selectively precipitate the vanadium at first, and adding a precipitant B to precipitate the chromium to obtain vanadium-rich residues and chromium-rich residues; and then separating and recycling the vanadium and the chromium from the vanadium-rich residues and the chromium-rich residues respectively. The vanadium and the chromium are separated and recycled effectively, and moreover, the effect of removing impurities simultaneously is achieved; liquor obtained after chromium precipitation is subjected to oxidization regeneration, evaporated and concentrated to obtain media, and the media are returned to an oxidation transformation procedure for the materials containing the vanadium or/and the chromium and are recycled. The method has the advantages of the simple technology, easiness and convenience in operation, the good vanadium and chromium separating effect, a high metal recovery rate, low production cost, environmental friendliness and the like, and is suitable for industrial application of extracting the vanadium and the chromium from the materials containing the vanadium or/and the chromium.

A method of treating a metallic surface which comprises treating a metal-coated steel panel with a nonchromate metallic surface treating agent containing, in each liter thereof, (a-1) a silane coupling agent and/or a hydrolytic condensation product thereof, (a-2) water-dispersible silica in a proportion, and (a-3) a zirconium compound and/or a titanium compound, drying the treated steel panel and coating it with an anticorrosion coating agent containing, in each liter of an aqueous resin solution or dispersion, (b-1) a silane coupling agent and/or a hydrolytic condensation product thereof, (b-2) water-dispersible silica and (b-3) at least one phosphorus-containing ion selected from among phosphate ion, phosphite ion and hypophosphite ion.

Chromate-free treatments and compositions, for applying a conversion or passivation coating to zinc coated metal surfaces. The compositions comprise a polyamidoamine/epihalohydrin polymer or cationic polyamine/epihalohydrin polymer component, fluoacid, H₃PO₄, and a film forming polymer latex component. The requisite metal surfaces are contacted by the compositions and dried. Rinsing is optional.

According to the present invention, a lithium ion battery outer cover material that has superior resistance to electrolytes without chromate treatment, has superior deep drawing formability and high quality, and can be produced easily is provided. The lithium ion battery outer cover material (1) of a first embodiment of the present invention has a base material layer (11), first adhesive layer (12) containing an adhesive, aluminum foil layer (13), corrosion prevention treated layer (14), second adhesive layer (15) containing an adhesive or adhesive resin, and sealant layer (16) laminated in that order. The base material layer (11) is a film base material in which the difference (α2−α1) of the elasticity (α1) to the yield point and the elasticity (α2) to the rupture point as measured according to JIS-K7127 is 100% or greater in at least one of the MD direction and TD direction.

This invention involves a preparation method for chromium oxide with chromium salt as raw materials and reducing gas as a reductant. Said method comprises carrying out reaction of chromium salt with superfluous reducing gas at 300~850DEG C for 0.5-3 h and cooling to obtain a reaction mixture, washing the mixture and drying, and calcining at 400~1100DEG C for 1-3 h to obtain the ultrafine chromium oxide powders, wherein the chromium salt is chromate or dichromate, and the reducing gas is hydrogen, natural gas, gas or their mixtures. Compared with existing technologies, this invention has the advantages of simple production process and being easy for industrialization. The obtained chromium oxide has high purity, uniform particle size distribution and small particle size. The whole process does not produce containing chromium-containing waste, and is environmental friendly. The reaction by-product can be reused, which greatly reduces the cost of production. Low reaction temperature greatly reduces the reaction energy.

The invention relates to coating technology, in particular to an environment-friendly polyaniline modified aluminium powder anti-corrosive coating and a preparation method thereof to solve the problemthat the prior aluminium powder coating has poor corrosion resistance, and is matched with harmful lead-containing and chromate-containing pigment in the manufacturing process. The environment-friendly polyaniline modified aluminium powder anti-corrosive coating comprises a film forming matter, polyaniline modified aluminium powder and the like. A polyaniline coating layer is formed on the surface of the aluminium powder by an oxidative polymerization method; the treated aluminium powder has passivating effect on metal; and a phytic coating layer on the surface of the aluminium powder also has corrosion inhibiting effect on the metal. The environment-friendly polyaniline modified aluminium powder anti-corrosive coating has strong corrosion resistance and permeability resistance, and can be applied to anti-corrosive projects such as petrochemical equipment, pipelines, offshore oil platforms, wharf facilities, shipping and the like.

The invention relates to coating technology, in particular to an environmental-friendly polyaniline modified micaceous iron oxide anticorrosive coating and preparation method thereof, which solves theproblem that the prior micaceous iron oxide coating has poor anticorrosion performance, and needs to be matched with pigments containing lead and chromate during manufacturing. The environmental-friendly polyaniline modified micaceous iron oxide anticorrosive coating comprises film-forming material, polyaniline modified micaceous iron oxide, and the like. As polyaniline coating layers are formedon the surfaces of the micaceous iron oxide by an oxidative polymerization method, the treated micaceous iron oxide has the effect of passivating metal, and phytic-acid coating layers on the surfacesof the micaceous iron oxide play a role in inhibiting corrosion of metal. The environmental-friendly polyaniline modified micaceous iron oxide anticorrosive coating has strong corrosion resistance andpermeation resistance, can be applied to heavy-duty engineering of petrochemical equipment, pipelines, offshore oil platforms, wharf facilities, ships and the like.

The invention discloses a non-chromium pretreating agent for a color coated steel plate, which is a solution prepared by mixing solute formed by multiple substances with deionized water according to the weight percentage of 1:4 to 7, wherein the solute includes the following substances by weight percentage: 0 to 10 percent of organic carboxylic acid containing 4 to 18 carbon atoms or water soluble salt thereof, 5 to 30 percent of organic polymer with molecular weight ranging from 3000 to 200000, 10 to 15 percent of salt with oxidation capacity, 15 to 60 percent of inorganic fluorochemical with the function of complexation, 5 to 10 percent of high valence state titanium salt, 5 to 15 percent of inorganic zinc salt and 5 to 30 percent of inorganic phosphate. The pretreating agent of the invention does not include substances harmful to the environment and human bodies, such as high valence chromate, and the like; meets the RoHs requirement, and belongs to environment-friendly green products. Proved by experiments, the product of the invention can greatly improve the binding force between a coating and a galvanized plate, and can enhance the decay resistance of the coating.

The invention discloses a copper and lead separating cyanide-chrome-free beneficiation method for low-grade multi-metal sulfide ore. The beneficiation method is performed according to the following steps that (1) raw ore after ore grinding and grading enters the step of copper and lead bulk flotation to obtain copper and lead bulk concentrate and bulk flotation tailings, beneficiation reagents including 25# black powder and tetrabutyl ammonium black powder are adopted as collecting agents for copper and lead ore, and sodium sulfite and zinc sulfate are adopted as inhibitors of zinc ore; (2) copper and lead separating flotation is performed on the copper and lead bulk concentrate to obtain qualified copper concentrate and lead concentrate, in the copper and lead separating flotation process, activated carbon is adopted for reagent removal, and an inhibitor combined by sodium sulfite, sodium carboxymethyl cellulose and sodium humate serves as the inhibitor of lead sulfide ore. The beneficiation method has the following advantages of being low in price and production and application cost, it is unnecessary to perform special treatment on ore pulp, the process is easy to control, and technological and economic indexes are stable. The great defect that a dichromate titration method, a cyanide method and a less-cyanide-chrome technology can cause pollution to the environment is overcome, and the usage amount of beneficiation new water is greatly reduced.

The invention discloses a method for recycling heavy metal resources of stainless steel pickling waste water neutralization sludge and belongs to the technical field of recycling of sludge after sewage treatment. The method comprises the following steps of: 1) performing acid pickling, namely extracting the stainless steel pickling waste water neutralization sludge by using sulfuric acid as extractant, and adding an additive to inhibit the leaching of ferrum; 2) oxidizing, namely adding oxidant into a leaching solution to oxidize Mn(II) into manganese dioxide; 3) performing ion exchange, allowing a solution obtained after oxidation to pass through an anion exchange column, enriching and recycling hexavalent chromium, adsorbing and saturating, regenerating by using regenerant, and recycling chromate from a regeneration solution; and 4) performing neutralization precipitation, namely recycling nickelous hydroxide from ion exchange effluent by a neutralization precipitation method. By the method, ferrum is inhibited at an acid pickling section, the acid pickling is performed while ferrum is removed, the multi-stage multi-step recycling of manganese, chromium, and nickel metal resources can be realized, the innocent treatment of sludge and recycling of heavy metal are realized, and the method has comprehensive benefit of economic benefit, environmental benefit and social benefit.

The invention relates to a method for extracting vanadium and chromium from a vanadium chromate mixed solution. The method has the characteristics that the vanadium in the vanadium chromate mixed solution is separated and recycled through the crystallization precipitation method or the hydrolysis precipitation method or the calcium salt precipitation method at first, then the chromium in the enrichment solution is separated through the copper salt precipitation method or the barium salt precipitation method, an obtained chromium precipitation enrichment product is then transformed into chromium enrichment liquid, the chromium enrichment liquid is further processed into products of chromic acid and chromate, and production of vanadium-chromium reducing slag and ammonia-nitrogen wastewater in the separation and recycling process of the vanadium and the chromium in the solution is effectively avoided. The method for extracting the vanadium and the chromium from the vanadium chromate mixed solution has the advantages of being good in vanadium and chromium separation effect, short in technological process, high in metal recycling rate, easy and convenient to operate, low in production cost, environmentally friendly and the like and is suitable for industrial production and application.

The present invention discloses one kind of chromium-free deactivator solution for preventing white rust in galvanized layer and its coating method. Into silane solution containing cilane coupler in 1-50 vol% concentration, molybdenate corrosion inhibitor in 1-30 g/L is added to compound pH 3-7 clear transparent deactivator solution. The deactivator solution is soaked, brushed or sprayed to the surface of galvanized layer to form one adhesive transparent spontaneously curing protecting layer with corrosion resistance similar to that of conventional chromate. The method can prevent white rust formed in the surface of galvanized product and is environment friendly.

A novel chromate-free multi-layer coating system composed of a lithium-doped potassium silicate binder based basecoat composition that is sealed with an aluminum phosphate-based top coat composition is described. The multi-layer coating system exhibits superior corrosion and heat oxidation resistance which can replace traditional chromate-containing coating systems.

The invention relates to a preparation technology of chromate, specifically to a three-phase catalytic oxidation preparation technology of soluble chromate. The technology comprises the following steps of: heating alkali liquor with concentration of 20-60% to 50-300 DEG C, then, mixing chromite or carbon ferrochrome with the alkali liquor according to mass ratio of Cr2O3 : alkali liquor = 1 : 1.5-10 to form suspending liquid, and introducing the suspending liquid into a reactor; continuously inputting the air or the oxygen heated to 50-300 DEG C to the bottom of the reactor through a pipeline; setting a catalyst in the reactor according to the mass ratio of catalyst : Cr2O3 = 0.1-1.5 : 100, maintaining the temperature of the suspending liquid in the reactor at 50-300 DEG C, executing gas-liquid-solid three-phase bubbling reaction for 0.5-6 hours to generate soluble chromate raw products and chromium residues; removing impurities through filtering and crystallization to obtain the chromate. With the three-phase catalytic oxidation preparation technology of the soluble chromate, Cr2O3 conversion rate is high, reaction speed is fast, energy consumption is low, residue quantity is low, environment pollution is less, equipment investment is low and corrosion is low.

A surface-treated sheet for fuel tanks includes a cold-rolled steel sheet with a low carbon content, a zinc or zinc-based alloy plating layer formed on the steel sheet, and a chromate film coated on the zinc or zinc-based alloy plating layer. The chromate film is formed from a chromate solution. The chromate solution includes a subject solution and an aqueous silane solution in an amount ranging from 5 to 50% by weight of the subject solution. The subject solution contains a chrome aqueous solution where the concentration of chrome is in the range of 5-50 g/l and the ratio of trivalent chrome to the chrome content is in the range of 0.4 to 0.8. Phosphoric acid in an amount ranging from 20 to 150% by weight with respect to the chrome content, fluoric acid in an amount ranging from 10 to 100% by weight with respect to the chrome content, colloidal silica having pH of 2-5 in an amount ranging from 50 to 2000% by weight with respect to the chrome content, and sulfuric acid in an amount ranging from 5 to 30% by weight with respect to the chrome content are mixed with the chrome aqueous solution. The aqueous silane solution contains 2-10 wt % of Epoxy-based silane and has a pH of 2-3. A resin coating layer is formed on one side or both sides of the chromate film. The resin coating layer is formed from a resin solution. The resin solution includes a phenoxy resin solution having a molecular weight of 25,000-50,000, colloidal silica of 10-20 phr with respect to the phenoxy resin content, and melamine resin of 2-15 phr with respect to the phenoxy resin content.

Chromate-free treatments and compositions for applying a conversion or passivation coating for metals, more particularly zinc coated metal surfaces. The methods of the invention comprise contacting the requisite metal surface with a phosphonomethylated polyamine. Other aspects of the invention involve methods and compositions in which the following optional components can be included: fluoacid, silane, inorganic phosphorus, acid, latex film forming component and pH adjustment agent.

A chromium VI reducing composition comprising particles of solid material selected from the group consisting of iron (II) sulfate and tin sulfate, the particles being substantially uniformly dispersed within a liquid carrier. Methods for modifying hydratable cementitious materials using the chromium reducing composition are also disclosed and provide advantages over dry powder or dissolved forms of sulfate compositions when used in cement manufacturing.

The invention relates to a water-based composite chromium-free passivation solution for a galvanized steel plate. The passivation solution contains 10-30g/L of sodium molybdate, 0-10g/L of sodium phosphate, 5-10g/L of organic phosphoric acid, 1-10g/L of fluotitanic acid, 5-15g/L of a silane coupling agent, 5-20g/L of sodium metasilicate, 0.1-1% of a wetting dispersant and the balance of deionized water. The passivation solution provided by the invention consists of an organic phosphoric acid-molybdate system in match with the modified hydrolysis type silane coupling agent and a nano-inorganic filler, does not contain a chromate and is in line with ROHS requirements; the passivation and drying curing time is short, the degree of stability is high, the quality of a film layer is good, the white rust area in a 72h salt fog test does not exceed 5%, the cost is relatively low, a passivation process device does not need to be changed, and continuous passivation can be realized by using a hexavalent chromium passivation device in early period.

The invention discloses a corrosion inhibitor and a using method thereof. The corrosion inhibitor is prepared from the following components including silica, oxygen-containing metal salt, a surfactant, organic siloxane and a solvent. The corrosion inhibitor does not contain toxic and harmful substances including chromate, nitrite and organic phosphine, and the metal surface subjected to coating treatment is good in corrosion resistance and finger resistant effect. The corrosion inhibitor is cheap, easily available, environmentally friendly and efficient as well as is simple and convenient in using method, good in stability and strong in practicability.

The invention relates to a chromium-free silicon passivation solution for passivating an aluminum or aluminum alloy surface, as well as preparation and using methods. The chromium-free silicon passivation solution is prepared by taking a silane coupling agent as a main agent, taking TEOS (tetraethyl orthosilicate) as an auxiliary agent, taking an inorganic salt or organic alkoxide acqueous solution of cobalt, zirconium, titanium and the like as a hydrolysis accelerator and adding an organic corrosion inhibitor. The passivation solution is free of chromium, fluorine or other toxic substances, a preparation process is simple, low in cost and suitable for industrial production, can be used instead of a chromate process, and has a wide application prospect, and a conversion coating after passivation is excellent in corrosion resistance.

The invention relates to an aluminum or aluminum alloy protection chromium-free passivation solution, a preparation method and an aluminum or aluminum alloy surface protection method thereof. According to the passivation solution, a silane coupling agent serves as a silicon source; an inorganic salt aqueous solution of rare earth ions serves as a hydrolysis accelerant. The organic-inorganic hybridized passivation solution free of chromium or fluorine or other toxic substances is prepared by adding an organic inhibitor. A hybrid film on the treated surface of aluminum alloy has the characteristics of being compact, uniform and high in corrosion resistance. The chromate process can be replaced. In addition, the adhesive force between the surface of the aluminum alloy and a coating can be improved.

The invention relates to a method for preparing chromate by alkaline roasting carbon ferrochrome, comprising the steps of: after milling the carbon ferrochrome into 300 meshes, mixing the carbon ferrochrome with 80-150% of alkali in a theoretical amount; roasting for 0.4-5h in an air atmosphere under 600-1200 DEG C, cooling, and leaching the chromate by water wherein the primary extraction rate is between 90% and 98%; if the leached residues contain much chromium, mixing the chromium residues with 80-200% of the alkali in the theoretical amount; roasting for 0.5-2h at the air atmosphere under 600-1200 DEG C, cooling, and leaching the chromate by water, wherein the total recovery rate of the chromate can reach up to more than 99.9%, and the content of the chromium contained in leached residues is lower than 0.05%; after simple treatment, discharging. The method is simple in process, low in equipment requirements and little in slag discharging amount; the method can solve the problem of severe pollution in production of the chromate; the prepared chromate products have high purity and can be easily and continuously prepared.