43 results about "Chromium product" patented technology

The invention relates to a method for separating and recycling vanadium and chromium from a vanadate-chromate-containing solution, which is characterized in that by using the difference of between anion exchange potentials formed by hexavalent chromium and quintavalent vanadium in water solutions by weak alkali and strong alkali anion exchange resins, saturation adsorption is utilized to implement deep separation of vanadium and chromium, thereby obtaining the vanadium and chromium products. The invention has the characteristics of short technological process, favorable separating effect, environment friendliness and the like, and is simple to operate. The invention can effectively shorten the technological process for separating and recycling vanadium and chromium from the vanadate-chromate-containing solution, enhance the separating effect of vanadium and chromium, lower the recycling cost of vanadium and chromium, and save the reagent consumption; and vanadium and chromium in the solution are deeply separated through ion exchange and are respectively recycled. The invention is suitable for industrialized application.

The present invention is carbon reducing process of producing metal chromium and can prepare metal chromium product with Cr content higher than 99 %, C content less than 0.02 % and O content less than 0.5 %.

The invention discloses a method for separating and recycling vanadium and chromium from a vanadium and chromium-containing material. The method comprises the following steps of performing selective oxidization reaction on the vanadium-containing material to oxidize low-valent vanadium in the vanadium-containing material into pentavalent vanadium, filtering and separating to obtain a chromium-containing solution and vanadium-containing enriched slag by adopting water leaching after oxidization is completed; regulating the pH of the chromium-containing solution to be naturalized to separate out chromium oxide hydrate precipitates, filtering and separating the chromium oxide hydrate precipitates to obtain chromium oxide hydrate, and further processing the chromium oxide hydrate obtained by filtering and separating to prepare chromium-series products; leaching the vanadium-containing enriched slag by an alkaline solution to obtain a vanadate solution; purifying the vanadate solution and removing impurities from the vanadate solution, then, precipitating and separating out ammonium metavanadate or ammonium polyorthovanadate in the presence of ammonium salts, and roasting the ammonium metavanadate or ammonium polyorthovanadate to obtain a vanadium pentoxide product. The method for separating and recycling vanadium and chromium from the vanadium-containing material is good in separating effects of vanadium and chromium and high in recovery rate. The vanadium product and the chromium product prepared are high in purity. Moreover, the method has the advantages of short process flow, simple and convenient operation, low production cost, environment friendliness and the like, and is suitable for industrial application.

The invention discloses a nickel-chromium plating part and a manufacturing method thereof. The nickel-chromium plating part includes a substrate, a pretreatment coating, a base layer, a functional layer and a decorative layer. The pretreatment coating is deposited on the entire substrate, and a copper plate layer is formed on the pretreatment coating; the base layer is formed on the copper plate layer; the functional layer is formed on the base layer and includes a low potential nickel layer and a microporous nickel layer formed on the low potential nickel layer; and the decorative layer is formed on the microporous nickel layer and is a trivalent chromium coating or a hexavalent chromium coating. Based on the micropores on the part surface and chrome plating technology, the low potential nickel layer is added to improve the corrosion resistance of the product, especially the corrosion resistance of trivalent chromium plating product, so as to promote the large scale popularization and application of the trivalent chromium product, which has better environmental protection performance.

The invention belongs to the technical field of refractory materials, and provides a preparation method of a compact chromium oxide product with high thermal shock resistance. According to the preparation method of the compact chromium oxide product with the high thermal shock resistance, the raw material of the chromium oxide product is composite chromium oxide micro-powder with the particle size of less than or equal to 45mu m; the composite chromium oxide micro-powder is prepared from chromium oxide micro-powder, titanium oxide micro-powder and a bonding agent. The preparation method comprises the steps of adding metal Zr micro-powder into the composite chromium oxide micro-powder; homogenizing and granulating the composite chromium oxide micro-powder to obtain a chromium oxide green body; replenishing an electric furnace, which contains the chromium oxide green body, with high-purity inert gas Ar; when the temperature is 1450-1650 DEG C, carrying out heat preservation for 2-8h, and sintering to obtain the compact chromium oxide product which is high in thermal shock resistance and has the chromium oxide content of more than 86%. The preparation method of the compact chromium oxide product with the high thermal shock resistance solves the problems that the compact chromium oxide product is great in density gradient difference of an inside body and an outside body, poor in thermal shock resistance, and the like, guarantees the uniformity of an internal structure of the compact chromium oxide product, and improves the sintering properties and use performance of large compact chromium products.

A method for recycling and preparing metal chromium comprises the steps of recycling chromium element from discharged waste liquid and discharged waste material, and utilizing the recycled chromium element to prepare metal chromium. The method prevents environmental pollution, realizes application of chromium resources, is simple in technology and low in cost, and can obtain metal chromium products which can meet the use requirement.

The invention relates to a clean production method in atmospheric pressure leaching of limonite type laterite-nickel ore with hydrochloric acid. The clean production method comprises the following steps: 1) mixing the limonite type laterite-nickel ore with hydrochloric acid for performing atmospheric pressuring leaching reaction; 2) performing calcination reaction to the pickle liquor obtained from the step 1); 3) dedusting the hydrogen chloride gas obtained from the step 2) to enter an absorption tower for producing hydrochloric acid, and collecting iron oxide powder; 4) washing and filtering the iron oxide powder, obtained from the step 3) with clean water; 5) performing liquid oxidizing reaction to solid filter cakes obtained from the step 4) to prepare corresponding chromium products, wherein the fine iron powder is obtained by slag phase; and 6) preparing the acid filtrate obtained from the step 4) into Ni and Co products. Through the clean production method, the separation of iron from nickel, cobalt and chrome in the atmospheric pressure leachate of the limonite type laterite-nickel ore can be realized, and the problem that the atmospheric pressure leachate of the limonite type laterite-nickel ore is difficultly treated can be effectively solved.

The present invention relates to one kind of selenium-rich and chromium-rich Saccharomyces cerevisiae, selenium-rich and chromium-rich Saccharomyces cerevisiae product and their production process. Of the selenium-rich and chromium-rich Saccharomyces cerevisiae product, each kilogram contains selenium in 100-4000 mg and chromium in 100-4000 mg. The selenium-rich and chromium-rich Saccharomyces cerevisiae may be used as selenium and chromium replenisher added into various food products or prepared into alone preparation. The selenium-irch and chromium-rich Saccharomyces cerevisiae product has lower toxicity than inorganic selenium and chromium product and high safety, and may be used in replenishing both selenium and chromium.

The invention discloses a production method of metal chromium. The production method includes the following steps that 1, chromium sesquioxide and aluminum powder are evenly mixed, and a mixed material is obtained; 2, an electrode is inserted into a smelting furnace, and then part of the mixed material is put in the smelting furnace; 3, the electrode is subjected to ohmic heating, the temperaturein the smelting furnace rapidly rises, and an aluminothermic reduction reaction is carried out; 4, after the interior of the smelting furnace reaches designated smelting temperature, the rest of the mixed material is put in the smelting furnace, the aluminothermic reduction reaction is carried out, the reaction is constant for a certain time, and it is guaranteed that the reaction is complete; 5,the electrode is powered off, heating stops, and the electrode is pulled out of the smelting furnace; and 6, the smelting furnace is cooled, subjected to slag removal, finished and broken, and the metal chromium product is obtained. Electric heating replaces a heating agent autothermal reaction, reaction conditions can be stabilized according to the aluminothermic reaction condition, the reactionuniformity is good, the consumption of an aluminum reducing agent is reduced by 20%, and the chromium yield is increased by 5% or above.

The invention discloses a method for selectively separating vanadium and chromium from a vanadium and chromium-containing solution. The method comprises the following steps of adding a pH regulator into the vanadium and chromium-containing solution to convert vanadium in the solution into polyvanadate and chromium into dichromate, then adding a selective floating extraction agent into the solutionto promote the floating extraction agent and polyvanadate to form a molecular associate, adding an associate stabilizer and a bubble dispersant, introducing air to enable bubbles to be hydrophobically mineralized to form polyvanadate-floating extraction agent-bubble micro-droplets, and finally deeply enriching and separating polyvanadate components through floating extraction; and adding a reducing agent into the chromium-rich flotation raffinate to reduce Cr<6+> into Cr<3+>, finally regulating the pH value of the solution to separate out chromium in the form of Cr(OH)3 precipitation, and drying and calcining the vanadium-rich and chromium-rich components to obtain the high-purity vanadium-chromium product. The method is good in selective separation effect on vanadium and chromium, simplein technological process, low in operation cost and particularly suitable for deep separation of vanadium and chromium.

An application of detoxicated Cr slags in preparing early-strenthening low-alkali cement and its products is disclosed. Said cement is prepared through proportionally mixing said detoxicated Cr slags with clinker and natural bihydrated gypsum. Its advantages are high quality of cement and no secondary pollution.

The invention relates to a rapid and accurate determination method of chromium and a chromium extracting and manufacturing product process. Chromium-containing substances such as metal chromium, chromium alloy, chromite and chromium compounds are dissolved by adding acid, impurities in the chromium solution are removed by adding special substances to prepare a high-purity chromium solution, and then the chromium solution is subjected to chemical method and instrument analysis to quickly determine the content of chromium and extract chromium to prepare chromium products. According to the rapidand accurate determination method, metal chromium ions are firstly purified, the influence of other metal ions on chromium is fully eliminated to enable the determination of chromium to be very fast and accurate, and the extracted chromium has high purity, so that the high-quality chromium series high-end products are prepared, and the rapid and accurate determination method is widely applied to different fields of the requirements of chromium series products.

The invention discloses a method for preparing a vanadium product and a chromium product from a double salt containing vanadium and chromium, and an application thereof. The method comprises the following steps: 1) mixing the double salt containing vanadium and chromium with water, and performing heating for dissolving to obtain a mixed solution containing sodium vanadate, sodium chromate, sodiumsulfate, sodium carbonate and sodium hydroxide; 2) performing a reaction by using a calcifying agent, and converting the sodium vanadate, sodium sulfate and sodium carbonate to form a precipitate; 3)performing separation to obtain a solid phase and a liquid phase; 4) dissolving the obtained solid by using an acid, adding sulfuric acid to make the pH value be 4-5, and performing separation; and 5)preparing the vanadium product from the liquid phase obtained by separation, and preparing the chromium product from the liquid phase obtained by separation. The method is a refining and separating method for vanadium-chromium mixed crystals, is adopted to prepare the qualified vanadium and chromium products, and solves the problem that the composite salt obtained from vanadium and chromium in the hydrometallurgy process cannot be productized.

The invention discloses a continuous production method for solid powder chromizing. The continuous production method comprises the following steps that (1) a workpiece is pre-buried in a powdery chromizing agent and contained in a load bearing box; and (2) chromizing treatment: the load bearing box filled with the workpiece and the chromizing agent is conveyed into a high-temperature furnace froma workpiece inlet through a conveying mechanism, the load bearing box sequentially passes through a heating zone, a heat preservation zone and a cooling zone of the high-temperature furnace and then is sent out from a workpiece outlet to complete chromizing treatment, protective gas is introduced into the high-temperature furnace, the flowing direction of the protective gas is opposite to the moving direction of the workpiece, the content of oxygen in the heat preservation zone is lower than 100 PPM, and the dew point is lower than -35 DEG C. According to the continuous production method for solid powder chromizing, the chromizing process is improved for the defects of the existing process, so that continuous production of chromizing can be realized; therefore, compared with the difficultyof the existing sealed processing, the processing difficulty is greatly reduced, the equipment requirement is low, the production efficiency is improved, the high-temperature furnace does not need tobe repeatedly heated and cooled to cause a large amount of loss of heat energy, the environment is protected, energy is saved, the processing cost is about 1/5-1/8 of that of the sealed processing, and the application range of chromizing products can be greatly expanded.

The invention relates to a treatment method for dirt on the surface of an electroplated chromium product. The treatment method comprises the processes of oil removal, coarsening, recycling, twice reducing, palladium activating, peptizing, chemical nickel plating, copper pre-plating, copper plating, acid activating, semi-bright nickel plating, bright nickel plating, nickel sealing, chromium plating, reducing and drying, wherein the next process is performed by washing after the front process, and in the reducing process and a washing process after the reducing process, liquid level of a reducing slot and liquid level of a washing slot after the reducing process are reduced; after the reducing process, twice spraying washing processes are increased; the drying process is performed after the spraying washing processes, and a hanger hung with an electroplated chromium product is unloaded to the ground through an unloading vehicle; and meanwhile, air curtain machines at the two sides of the unloading vehicle perform gas blowing on the electroplated chromium product. The treatment method has the advantages that: a dirt phenomenon on the surface of the product can be effectively removed, the comprehensive qualification rate of the product is increased, and great cost caused by goods return as the product is dirty is reduced.

The invention discloses a vanadium-containing and chromium-containing raw material combined sodium salt roasting method which comprises the following steps: mixing two or more vanadium-containing and chromium-containing raw materials, and then adding a sodium salt auxiliary agent for mixing; putting the mixed raw material into a kiln for roasting to obtain roasted clinker; the obtained clinker is smashed and put into water to be soaked after being smashed, or the clinker is directly put into water without being smashed and stirred when the clinker is still hot, a water-soluble vanadium-chromium compound in the clinker is fully dissolved into water and filtered, filtrate obtained through first-time filtering is high-concentration leaching liquid and is used for producing vanadium-chromium products, filter cakes are washed with clear water again, and the vanadium-chromium product is obtained. Residual soluble vanadium and chromium compounds in the filter cake are taken away until the filter cake is cleaned up. The method is simple in process, low in roasting temperature, capable of recycling water and free of hazardous waste, the vanadium resource extraction rate can reach 95% or above, the chromium extraction rate can reach 85% or above when a high-chromium raw material is used, the chromium extraction recovery rate can reach 75% or above when a low-chromium raw material is used, and the method is suitable for efficient recovery of resources of different vanadium-containing and chromium-containing materials.