8 results about "Potassium nitrite" patented technology

The invention relates to the technical field of zinc hydrometallurgy, and discloses an analysis method for measuring high cobalt content by an EDTA complexing back titration method, which is based on the following steps: oxidizing Co < 2 + > into Co < 3 + > by using potassium nitrite in an acetic acid medium to form cobalt potassium nitrite precipitate so as to realize separation of cobalt and interfering ions, dissolving the precipitate, complexing with excessive EDTA, and performing back titration by using a zinc standard solution. Xylenol orange is used as an indicator, and determination is completed at room temperature in a hexamethylenetetramine buffer system with the pH value being approximately equal to 5.8. Coexisting ion interference is effectively eliminated through tartaric acid, sodium fluoride, thiourea and other masking agents, the method has the advantages of being easy and convenient to operate, sensitive in end point, high in accuracy and low in cost, and the requirement for conventional analysis of high-cobalt materials can be met.

The present application provides a kind of nitromethane tail gas treatment method, comprising the following steps: sodium hydroxide or potassium hydroxide aqueous solution and low-grade fatty diol and organic base miscible to form mixed solution after preheating, then nitromethane tail gas is passed into mixed solution and reacts, reaction end product is separated and purified to obtain corresponding sodium nitrite or potassium nitrite product.The present application also provides a kind of nitromethane production method, including the sodium nitrite or hydrogen potassium obtained above as raw material to recycle production nitromethane.The method of the present application solves the problem of nitromethane tail gas treatment, also can turn waste into treasure, reduce production cost, conducive to nitromethane production and environmental protection.

The invention relates to an electrolyte additive, a zinc-nickel battery and a preparation method of the zinc-nickel battery. The zinc-nickel battery electrolyte comprises the following components in percentage by mass: 25%-45% of potassium hydroxide, 1%-4% of zinc oxide, 0.2%-5% of potassium nitrite, 0.2%-1% of cerous sulfate and the balance of water. According to the zinc-nickel battery electrolyte, the cycle life of the battery is greatly prolonged, the safety of the battery is greatly improved, gas production of the battery is effectively inhibited, the cycle stability is improved, corrosion of a negative electrode active material and a current collector is effectively slowed down, the self-discharge rate of the battery is reduced, the capacity retention rate of the battery is remarkably improved, and the service life of the battery is prolonged. The ion concentration and conductivity in the electrolyte are improved, the internal resistance of the battery is reduced, the high-current charge-discharge capacity of the battery is improved, the electrolyte is prevented from being dried up due to water evaporation in the long-term cycle process, and the long cycle life and stability of the battery are further guaranteed. The zinc-nickel battery electrolyte is simple in preparation process flow, and the commercialization difficulty and cost are reduced.

The present invention relates to the technical field of organic synthesis, and more particularly to a method for preparing a Disperse Black 9 compound. The method comprises the following steps: S1, diazotization reaction: under an inert gas environment, diazotization reaction of p-phenylenediamine, nitrite, and an inorganic acid aqueous solution to obtain a reaction solution; S2, coupling reaction: adding N,N-bishydroxyethylaniline to the reaction solution of step S1 for a coupling reaction, and after completion of the reaction, post-processing to obtain the Disperse Black 9 compound. The nitrite is at least one of sodium nitrite and potassium nitrite. The inorganic acid aqueous solution is selected from the group consisting of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, and nitric acid aqueous solution; the mass concentration of the inorganic acid aqueous solution is 30% to 80%. The method can achieve a one-pot preparation of a target compound with high purity and high yield, and is simple to operate, low-cost, and environmentally friendly.

The present invention discloses a stripping solution and a stripping method for unqualified cadmium plating layers. The stripping process is as follows: the oxidant is 50 - 160 g / L, the complexing agent is 50 - 160 g / L, the pH of the stripping solution is 6 - 8, and the operation is carried out at room temperature. The oxidant includes one or two of sodium nitrite and potassium nitrite, and the complexing agent includes one or two of ammonium sulfate, ammonium bicarbonate, ammonium carbonate, and ammonium chloride. When the pH of the stripping solution is too low, the pH is increased with sodium carbonate solution or sodium hydroxide solution; when the pH is too high, the pH is decreased with dilute nitric acid or dilute sulfuric acid. Nitrite in the stripping solution has a corrosion inhibition effect on the steel substrate, and there is no corrosion on the steel surface during stripping. The technical solution of the present invention overcomes the high pollution problem of the chromic acid cadmium stripping process in the fields of aerospace and military industry, etc.

The application belongs to the field of nanometer material and energy environment science and engineering, and particularly relates to a preparation method and application of superfine copper oxide nanometer material for promoting electrocatalysis to construct C-N bond to synthesize urea. The application uses an oil phase environment to synthesize superfine nanometer copper oxide particles with uniform size. The electrocatalyst prepared in the application has a large number of crystal boundary and amorphous / crystalline phase heterophase boundaries. The copper atoms and obvious crystal boundaries scattered and distributed on the surface of the nanometer particles can be directly observed by using a high-resolution transmission electron microscope. Inorganic raw materials, carbon dioxide and potassium nitrite, are used as carbon source and nitrogen source respectively to synthesize urea, an organic compound containing C-N bond, in a normal temperature environment. The synthesis method is simple and easy to operate, and can be popularized on a large scale. In the currently used materials for C-N bond coupling, the performance is excellent.

The invention discloses a method for constructing a nano material based on a multi-element nitrite eutectic salt system, and belongs to the technical field of nano material synthesis, and the method specifically comprises the following steps: putting sodium nitrite and potassium nitrite into an air muffle furnace, and preheating into molten salt; the method comprises the following steps: dissolving at least one metal salt in a solvent, mixing and reacting with molten salt, preserving heat, cooling and cleaning to obtain a nano material, particularly a nano main body material or a material in which at least one rare earth element is loaded in a bulk phase of the nano main body material in a monatomic form, and the nano main body material is a nano metal or oxide nano material; by controlling the mixing ratio of sodium nitrite to potassium nitrite, the heat preservation temperatures of different metal salts are adjusted, so that different nano materials are synthesized. According to the method, the nano material is synthesized from different metal salt precursors at low temperature in one step, and the method has the advantages that the different metal salt precursors are rapidly and simultaneously nucleated, the size of a target product is controllable, and a readily oxidizable material phase can be directly synthesized, and has important significance on potential application of the method in various fields.

The application discloses a salt additive melt blending pretreatment method of PET products. After the PET products are crushed, the salt additive is mixed, melt blending is carried out at 268-275 DEG C for 4-5 minutes, direct cooling is carried out without quenching, crushing and 80 mesh screening are carried out, and a pretreatment product is obtained. The salt additive is selected from one or more of sodium nitrate, sodium nitrite, potassium nitrate, potassium nitrite, calcium nitrate, calcium nitrite, sodium bisulfate, potassium bisulfate, sodium phosphate and potassium phosphate, and the addition amount is 0.5%-1.0% of the mass of the crushed PET material. The method can control the crystallinity increase, improve the powder yield, and the obtained product can be used for subsequent enzymolysis.