9results about "Ammonium nitrates" patented technology

The present application relates to the technical field of ammonium nitrate production equipment, and provides a neutralization reaction device for ammonium nitrate solution, which comprises a reactor, a dilute nitric acid conveying unit, an ammonia gas evaporation unit, a liquid-phase pH detection device and a controller; the dilute nitric acid conveying unit is in communication with a dilute nitric acid control valve; the ammonia gas evaporation unit is in communication with an ammonia gas control valve; the liquid-phase pH detection device is in communication with a liquid-phase pH detection sampling valve; the controller is electrically connected with the liquid-phase pH detection device, the liquid-phase pH detection sampling valve, the dilute nitric acid control valve and the ammonia gas control valve respectively; and the controller is also used for receiving detection parameters of the liquid-phase pH detection device and adjusting the opening degrees of the dilute nitric acid control valve and the ammonia gas control valve, so as to adjust the liquid-phase pH value in the reactor. By adjusting the feeding ratio of the two raw materials of dilute nitric acid and ammonia gas, the liquid-phase pH value in the reactor can be directly controlled to be stable in a safe range. The pressure fluctuation in the reactor can be reduced, and the flow stability of ammonia gas and dilute nitric acid entering the reactor can be improved.

The present application belongs to the technical field of energy saving and consumption reduction of titanium dioxide production, and particularly relates to a method for energy saving and pollution reduction in the calcination process of sulfuric acid method titanium dioxide. The present application realizes the cascade utilization of high-temperature to medium-low-temperature waste heat through the integrated scheme of "preheating and quality improvement + oxygen-rich calcination + tail gas synergistic desulfurization and denitrification + resource utilization of by-products", that is, the calcination tail gas (1000-1100℃) is first used to generate steam for production through a waste heat boiler, and then is used for preheating and drying metatitanic acid after being cooled, thereby realizing the cascade utilization of high-temperature to medium-low-temperature waste heat, and simultaneously, the oxygen-rich combustion improves the fuel efficiency, the natural gas combustion is more sufficient, the energy consumption per unit product is reduced by 30-40%, and the ammonia method is used to simultaneously remove SO2 and NO x in a single reactor, the desulfurization efficiency is greater than or equal to 95%, the denitrification efficiency is greater than or equal to 85%, the concentration of dust in the tail gas after being removed by a bag filter is less than or equal to 10 mg / Nm3 for emission, the unity of environmental benefits and economic benefits is realized, and a new path is provided for the green upgrading of the sulfuric acid method titanium dioxide industry.

The application discloses a method and system for preparing ammonium bifluoride from hydrofluoric acid waste liquid, which comprises the following steps: (1) adding the hydrofluoric acid waste liquid into an electrolytic cell, transporting the electrolytic cell to a first reaction kettle after electrodepositing treatment, adding silicon dioxide, then stirring and reacting, and returning the generated silicon tetrafluoride and hydrofluoric acid into a spray tower to react and then return to the first reaction kettle, and then adding ammonia water to perform neutralization reaction; (2) filtering the solid-liquid mixture I, evaporating and drying the obtained filtrate I to obtain an ammonium nitrate product, and returning the obtained filter cake I to a second reaction kettle, adding ammonia water to adjust the pH value, and then stirring and reacting; (3) filtering the solid-liquid mixture II, returning the obtained filter cake II to the first reaction kettle for reuse, transporting the obtained filtrate II to a reactor, adding hydrofluoric acid to perform reaction, and then performing evaporation and drying treatment to obtain an ammonium bifluoride product. The method is simple in process, low in energy consumption, convenient to operate and convenient for industrialized production and application.

The application provides a method for preparing carboxylic acid by hydrolysis of nitrile, wherein the nitrile and protonic acid are subjected to hydrolysis reaction in a microwave reactor in the presence of solid inorganic medium to obtain the carboxylic acid; wherein the frequency of the microwave reactor is 0.9-3.0 GHz; the nitrile is aliphatic nitrile, aromatic nitrile or a mixture thereof; the relative dielectric constant ε of the solid inorganic medium is 30-500. r The application realizes microwave-high dielectric medium coupling reinforcement through the cooperation of the solid inorganic medium with specific relative dielectric constant and specific microwave reaction condition, can realize the efficient obtaining of high-purity carboxylic acid product, and produces ammonium salt as by-product. The overall method has high yield, strong raw material universality, is easy to be industrialized and amplified, and has remarkable economic effect.

Provided herein are systems and methods for producing renewable nitrogen products.

The present application relates to the technical field of reactor, and provides a safe starting method of ammonium nitrate volumetric reactor, which comprises the following steps: S1, saturated steam is introduced into a steam pipeline connected with the reactor to carry out hydrophobic preheating and pressure increasing operation until the pressure in the steam pipeline is stable; S2, liquid medium is added into the reactor to establish an initial liquid level; S3, saturated steam is introduced into the bottom of the liquid phase in the reactor by using the steam pipeline to heat and pressurize the liquid phase in the reactor, and ammonia gas is introduced into the liquid phase in the reactor to adjust the pH value of the liquid phase; S4, when the temperature of the liquid phase in the reactor, the top pressure, the pH value of the liquid phase and the pH value of the gas phase all reach preset starting conditions, ammonia gas and dilute nitric acid are put into the reactor to start the neutralization reaction to produce.The present application can eliminate the huge temperature difference between the reaction zone and the surrounding liquid phase from the source, improve the safety and stability of the starting process of the device, and improve the production efficiency.

The application belongs to the technical field of wastewater treatment, and particularly relates to a comprehensive utilization method of sulfuric acid and nitric acid mixed acid wastewater. The method comprises the following steps: S1, mixing the sulfuric acid and nitric acid mixed acid wastewater and waste PCB circuit board, and performing a self-catalytic oxidation reaction, pressure filtration, to obtain a copper sulfate solution and tail gas; S2, adding urea to the copper sulfate solution, adding phosphoric acid and ammonia water after no bubbles are generated, stirring, filtering, to obtain a purified copper sulfate solution; the purified copper sulfate solution is subjected to evaporation crystallization, centrifugation and washing separation, to obtain copper sulfate pentahydrate; S3, the tail gas in step S1 is subjected to spray absorption, to obtain dilute nitric acid, and then lime is added to adjust the pH to 1.2-1.6, and then ammonia water is added to adjust the pH to 7, to obtain a calcium ammonium nitrate mother liquor, and the calcium ammonium nitrate mother liquor is subjected to evaporation crystallization and granulation, to obtain calcium ammonium nitrate. The application first cooperatively prepares high-purity copper sulfate pentahydrate and calcium ammonium nitrate from the sulfuric acid and nitric acid mixed acid wastewater and the waste PCB circuit board.

Disclosed is a system for the production of urea ammonium nitrate (UAN), which is particularly suitable for processing relatively small ammonium nitrate waste streams into UAN. The system comprises a concentration for ammonium nitrate, a treatment section which allows recovering and recirculating nitrogen compounds entrained in vapor from the concentration section, and a pH control section allowing to adjust the pH of the processed ammonium nitrate waste stream to the extent necessary.