40 results about "Basic chromium sulfate" patented technology

The invention relates to a method for separating and recovering vanadium and chromium from vanadium-chromium reduced waste residue. The method comprises the following main steps of: after removing water-soluble salts through slurrying and washing, extracting vanadium from the rest vanadium-chromium reduced waste residue by oxidizing in an alkaline solution; meanwhile, realizing the vanadium-chromium separation; cooling and crystallizing a leaching solution to obtain obtaining a sodium orthovanadate product; carrying out acid leaching on the vanadium-chromium reduced waste residue subjected to vanadium extraction; and preparing a basic chromium sulfate product after removing impurities, evaporating and crystallizing. According to the invention, the purity of the sodium orthovanadate product prepared by the method is higher than 93%, the content of Cr2O3 in the basic chromium sulfate can reach 24%, the content of Fe is lower than 0.1%, and the requirements on the basic chromium sulfate I type product in the HG / T 2678-2007 are met.

The invention discloses a method for preparing chromium sulfate basic by utilizing residual liquor obtained during menadione production. The method comprises the following steps: uniformly mixing the concentrated residual liquor with industrial sugar according to a certain molar ratio, and reacting in a pressure reactor for 0.5-4 hours at the temperature of 100 to 300 DEG C under the pressure of 0 to 4MPa; completely reducing a small amount of unreacted hexavalent chromium in the feed liquid into trivalent chromium by using a reducing agent after the reaction is ended; regulating the basicity of the feed liquid by using an alkaline solution, filtering, performing spray drying on the filtrate, thus obtaining the chromium sulfate basic product. According to the method disclosed by the invention, a pressure-conditioned curing reaction is adopted, residual organic matters in the menadione residual liquor can be effectively removed, and the quality of chromium powder is improved. The method disclosed by the invention is simple in process, high in reaction rate, low in energy consumption, clean and environment-friendly.

An nickel plating layer (5a) intended for corrosion current distribution is formed over a body (2), and a 0.05 to 2.5 micrometers thick surface chrome plating layer (6) made of trivalent chromium is formed on the surface thereof using basic chromium sulfate as a source of metal. Further on the same, a not less than 7 nm thick chromium compound film (7) is formed by cathode acidic electrolytic chromatin. The corrosion distribution nickel plating layer (5a) has a function of forming a microporous structure, a microcrack structure, or the both of the same in the surface chrome plating layer (6).

The invention provides a method of preparing a basic chromium sulfate tanning agent from chromite sulfuric acid leachate, belongs to the technical field of ore processing, and aims to solve the problem that iron cannot be removed from chromite sulfuric acid leachate easily in the prior art. In the provided method, the temperature of chromite sulfuric acid leachate is controlled in a range of 60 to 100 DEG C, the pH value is controlled in a range of 1 to 3, then a pyrite crystal seed is added to carry out crystallization; then the crystals are filtered to obtain pyrite crystals and a filtrate; the temperature of the filtrate is maintained, the pH of the filtrate is adjusted to a range of 2 to 4, then adding a goethite crystal seed to carry out crystallization; the crystals are filtered to obtain goethite crystals and a filtrate; a diluted alkali solution is added into the filtrate to neutralize the filtrate, after neutralization, the basicity of the solution is in a range of 32 to 34%; and then the solution is dried to obtain the basic chromium sulfate tanning agent. During the preparation process, no virulent Cr(VI) is generated; the method is clean and nontoxic therefore, moreover, the iron is removed in two steps, thus the iron is almost removed, and the iron content of the obtained basic chromium sulfate tanning agent in mass percentage is less than 0.1%.

The invention relates to a process for treatment of heavy metal and recovery of an inorganic salt and especially to a process for preparing basic chromium sulfate by using a waste chromium material. In the process, a waste chromium liquid storage tank, an acidifying device, a reduction device, a reaction vessel, a condensation kettle, a press filtration device, a spray drying device and a gas purifying device are utilized; the process comprises the following steps: collecting electroplating and other chromium-containing waste liquid and waste residue, adding the collected waste liquid and waste residue into an acidifying reaction vessel, optimizing a formula for reagents, removing other impurity components except chromium components through addition and reaction of the reagents and press filtration, carrying out further dehydration by adjusting the condensation kettle for further reaction and preparing the product of basic chromium sulfate by using a centrifugal spray drier. The process provided in the invention is optimized, reasonable, simple and easy, makes the most of natural resources and natural conditions, has the advantages of low production cost, small investment and high yield and enables the problem of waste chromium pollution to be effectively overcome and the waste chromium material to be processed into inorganic chemical products, thereby producing remarkable environmental and economic benefits.

The invention discloses a method for preparation of basic chromium sulfate from chromium phosphate, relates to a method for preparation of the basic chromium sulfate from chromium-containing material chromium phosphate, particularly relates to a method for extraction and separation of chromium in mixed electroplating sludge and phosphorus chromium slag to obtain chromium phosphate and then extending preparation of the basic chromium sulfate. The method is characterized by sequentially comprising the following steps: (1) adding water into a chromic phosphate raw material for mixing slurry; (2) adding a reducing agent for reducing processing; (3) adding an alkali for phosphate radical removal reaction; (4) filtering to obtain chromium hydroxide and alkali liquid; (5) redissolving the chromium hydroxide with sulfuric acid; (6) adding NaOH alkali solution into redissolving solution to adjust solution pH, aging to obtain basic chromium sulfate solution; and (7) evaporating and crystallizing to obtain basic chromium sulfate. The method is a simple-process short-flow environmentally-friendly high chromium value utilization hydrometallurgy technology, and is suitable for application in the field of resource utilization of chromium phosphate in electroplating sludge, chromium phosphate slag and waste slag sludge.

The invention discloses a method for preparing a basic chromium sulfate-chrome tanning agent by using lignite wax as a reducing agent. The method comprises the processes of primary oxidation, secondary oxidation and oxidation liquid modulation, wherein the primary oxidation comprises the steps of acidizing the lignite wax for 1 hour and then stirring and oxidizing for 4-6 hours; the secondary oxidation comprises the steps of acidizing the primary oxidation liquid for 20-40 minutes and then stirring and oxidizing for 2-3 hours; the method further comprises the steps of adding the primary oxidation liquid and the secondary oxidation liquid into a reaction kettle, determining the adding amount of an oxidizing agent and a reducing agent, adding the oxidizing agent and the reducing agent into the reaction kettle sequentially and slowly, strictly controlling the reaction temperature at 105-115 DEG C, stirring and oxidizing for 1-2 hours, standing, ageing, spray-drying and forming to obtain the basic chromium sulfate-chrome tanning agent. Compared with the pure sugar reducing agent, the neutral salt content of the basic chromium sulfate-chrome tanning agent is reduced by above 30 percent, the chrome absorption quantity of leather is enhanced, and the plumpness and humidity-resistant and heat-resistant stability of the leather are improved. The basic chromium sulfate-chrome tanning agent comprises organic micromolecular acid with a good masking effect, particularly sulfonated phthalic acid, so that the leather is plump and soft, and has elasticity, natural brightness and wax feel.

The invention discloses a method for preparing basic chromium sulfate tanning liquor by using tanning chromium sludge, and solves problems in existing method for preparing tanning liquor by using tanning chromium sludge, such as violent reaction, high operation risk coefficient, incomplete organic compound hydrolysis, poor infiltration of the obtained tanning liquor and complex preparation process and steps. The method comprises the following steps: (1) homogenization; (2) leaching; (3) filter pressing; (4) pressure reduction; and (5) cooling and depressurization. The invention has beneficial effects of mild chemical reaction, easily controlled reaction, capability of completely reducing hexavalent chromium to trivalent chromium, low production cost, no introduction of new impurity, simple processing steps, high purity of the finally obtained chrome tanning liquor, high reduction rate of hexavalent chromium, small consumption amount of ethanol or industrial alcohol, deep hydrolysis of organic small molecules, further enhancement of purity and tanning property of the finally obtained tanning liquor.

The present invention relates to a migration-resistant red dye, a preparation method therefor and application thereof. The preparation method for the dye comprises the following steps: (a) mixing 2-amino-5-nitrophenol, 2-aminophenol-4-sulfamide, sodium nitrite, hydrochloric acid and water to react, and obtaining a diazonium product; (b) adding a mixed solution of 3-(4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl) benzenesulfonamide, caustic soda liquid and water to a vessel to react with the resulting diazonium product in the step (a), and obtaining a coupling product; (c) performing chromium complexation on basic chromium sulfate and the resulting coupling product in the step (b); (d) reacting a product obtained from the chromium complexation with a mixed solution of formic acid, n-tridecyl amine and water; and (e) after completion of the reaction, filtering and drying. The dye is resistant to a high temperature, is relatively inexpensive, and has good migration resistance.