536results about "Sulfur compounds" patented technology

The invention discloses a device and a method for regenerating a powdery iron oxyhydroxide desulfurizer and purifying sulfur, and the device and the method are characterized in that invalid iron oxyhydroxide is completely reduced into a ferrous oxide and ferrous sulfide after sulfide is added, the reaction of an iron compound is enhanced through ultrasound and stirring, and the separation of the iron compound and the sulfur is promoted. Further fully aerating to fully oxidize the ferrous iron to generate new iron oxyhydroxide; at the moment, the iron oxyhydroxide is in a completely dispersed state, the single particle size is not higher than 1 micron, and small flocs with the particle size of 0-5 microns are formed in laminar water; the surface of the sulfur has hydrophobicity, and the sulfur is gathered to generate hydrophobic self-flocculation, so that large flocs with the particle size of 30-300 microns are formed in the laminar water; the mixture is flushed by water flows with different flow speeds, the iron oxyhydroxide with small particle size is flushed out at a certain flow speed, and the sulfur with large particle size is suspended in the grading pipe, so that the regeneration of the iron oxyhydroxide desulfurizer and the purification of the sulfur are realized.

The utility model discloses a quenching purification system for sulfuric acid recovery. A Venturi section comprises a flue gas inlet section, a reducing section, a throat section, an expanding section and a settling section which are sequentially communicated from top to bottom; the settling section is provided with a cavity, and a horizontal flue gas pipeline is arranged on the side wall of the settling section; a flue gas outlet of the horizontal flue gas pipeline is connected to the quench tower; the quench tower comprises a gas-liquid separation section connected with a flue gas outlet of the horizontal flue gas pipeline, a gas-liquid distribution and collection unit, a filler layer, a spraying layer and a demisting layer are sequentially arranged on the upper side of the gas-liquid separation section, and a liquid phase of the gas-liquid distribution and collection unit is collected to the collection tank. According to the utility model, the design that the Venturi section and the quench tower are connected in series is adopted, the Venturi section can quickly cool high-temperature flue gas to a saturation temperature, break aerosol, absorb SO3 in the flue gas and wash dust, and the quench tower realizes deep quenching and purification of the flue gas, prevents corrosion of subsequent equipment and ensures long-period operation of downstream devices in a sulfuric acid recovery process.

The invention discloses a vanadium catalyst for preparing sulfuric acid through wet conversion as well as a preparation method and application of the vanadium catalyst, and belongs to the technical field of catalysts. By improving a catalyst formula and a preparation process, a silicate aid is added to generate crystal silicon dioxide to regulate the structure of a diatomite carrier, and the heat resistance and hydrothermal stability of the catalyst are improved; the rare earth additive is added to modulate the active phase of the catalyst, so that the activity of the catalyst in a wide temperature range (380-600 DEG C) is improved, and the requirement of modern development of preparing sulfuric acid by wet conversion can be met. The preparation method is improved on the basis of a traditional vanadium catalyst wet mixing method preparation process, the active component of the catalyst is changed into slurry from colloid, uniform mixing of the active component and a carrier is facilitated, the active component is uniformly dispersed, the utilization rate of the active component is increased, and the performance of the catalyst is improved.

The invention provides a method for recovering lithium phosphate from a lithium iron phosphate positive electrode material, which comprises the following steps: carrying out oxidation leaching on the lithium iron phosphate positive electrode material by using an acid solution and an oxidizing agent to obtain a first leaching solution and a first leaching residue; after water is added into the first leaching residues for size mixing, alkali leaching is conducted through sodium hydroxide, second leaching liquid and iron / carbon insoluble residues are obtained, and sodium phosphate crystals are obtained after the second leaching liquid is condensed; carrying out lithium precipitation reaction on the first leaching solution by using the sodium phosphate crystal to obtain lithium phosphate and lithium precipitation residual liquid; the lithium precipitation residual liquid is subjected to concentration and impurity removal, and then is subjected to a bipolar membrane electrodialysis process to obtain an acid solution and sodium hydroxide for reutilization. The invention aims to provide a method for mutually separating lithium, iron and phosphorus aiming at the waste lithium iron phosphate positive electrode material, the method can almost completely recover lithium, iron and phosphorus in the lithium iron phosphate positive electrode material, and the lithium is high in recovery rate and high in purity.

The invention discloses an ardealite resource comprehensive utilization method and application thereof, and belongs to the technical field of ardealite resource utilization. The method comprises the following steps: S1, mixing ardealite and a reducing agent to obtain a mixture; s2, performing high-temperature decomposition treatment on the mixture in an inert atmosphere to obtain decomposed gas and a decomposed product; s3, sulfuric acid and / or carbon disulfide are / is prepared with the decomposition gas as the raw material, and the decomposition product is used for metallurgical steelmaking; according to the method, ferrous sulfide is used as a reducing agent, under the inert atmosphere, phosphogypsum is reduced into calcium oxide and calcium ferrite, generated sulfur dioxide tail gas is recycled, and comprehensive utilization of calcium and sulfur resources of phosphogypsum solid waste is achieved; the recycled sulfur dioxide can be used for preparing sulfuric acid and / or carbon disulfide, meanwhile, calcium oxide and calcium ferrite can serve as an adhesive and a slag former to be used for efficient metallurgical steelmaking, and the comprehensive utilization method for ardealite resources has a good application prospect.

The invention discloses a waste sulfuric acid treatment method and device, the device comprises a sintered filter element filter, a fine filtration coalescer, an adsorption tank and a membrane separator which are connected in sequence, and the fine filtration coalescer adopts a ceramic membrane tube or a polytetrafluoroethylene membrane tube or a silicon carbide lining membrane tube as a filter material; an adsorption material in the adsorption tank is one or a combined adsorption material of more than two of activated carbon, a modified molecular sieve, a metal organic framework material and a nano adsorption material; and the membrane separation system adopts one or a combined membrane of more than two of an ultrafiltration membrane, a reverse osmosis membrane and an electrodialysis membrane. The alkylation waste acid regeneration process can be simplified, the occupied area of the device is saved, the engineering investment is reduced, and the operation cost is greatly reduced compared with that of an existing process technology; according to the method, a physical separation means is adopted, organic polymeric oil, dissolved organic matters, dissolved salts and other impurities in the alkylated waste sulfuric acid can be effectively removed without decomposing and reconstructing the waste sulfuric acid, and the concentrated sulfuric acid after concentration completely meets the production requirements of an alkylation device.

The invention belongs to the field of inorganic chemical industry, and particularly relates to a method and a system for efficiently utilizing a phosphate fertilizer byproduct, the method comprises the following steps: carrying out acidolysis on fluosilicic acid with the concentration of more than or equal to 45% wt and concentrated sulfuric acid to generate a mixed solution of silicon tetrafluoride gas and fluorosulfonic acid; the mass ratio of the fluosilicic acid to the concentrated sulfuric acid is controlled to be 1: (4-15); pyrolyzing the obtained fluorosulfonic acid to generate dilute sulphuric acid, hydrogen fluoride and water vapor, forming 98% concentrated sulphuric acid from part of dilute sulphuric acid and fuming sulphuric acid, drying hydrogen fluoride to obtain crude hydrogen fluoride gas, and condensing and rectifying to obtain anhydrous hydrogen fluoride; the rest dilute sulphuric acid is partially compounded and then returned for acidolysis, and the rest dilute sulphuric acid is used for producing white carbon black and flows back to a wet-process phosphoric acid system; and circularly absorbing the obtained silicon tetrafluoride gas by using secondary concentrated fluosilicic acid to obtain fluosilicic acid with the mass concentration of more than or equal to 45%, recycling the fluosilicic acid for acidolysis reaction, and modifying the concentrated by-product silicon dioxide to obtain the high-activity white carbon black. The problems of energy consumption and cost are solved, and efficient circulation and poly-generation of fluorine and silicon resources are achieved in the whole process.

The invention relates to the technical field of chemical raw material preparation, and discloses a process and equipment for preparing liquid sulfur dioxide through pure oxygen incineration, the system deeply couples dynamic optimization of three high-energy-consumption links of waste heat recovery, combustion reaction and deep freezing through hardware collaboration and algorithm innovation, and compared with a traditional process, the comprehensive energy consumption of unit products is reduced by 35%, and the production cost is reduced. Meanwhile, the three technical problems of liquid sulfur solidification, furnace temperature out-of-control and non-condensable gas accumulation are solved.

The invention discloses a process for producing electronic-grade sulfuric acid based on absorption and desorption of organic amine. The process comprises the following steps: treating SO2 flue gas containing other components through an organic amine absorption and desorption process to obtain SO2 saturated gas of which the products are pure SO2 and water; high-concentration SO2 gas can be obtained through condensation and gas-liquid separation; mixing with pure O2 and inert gas to obtain SO2 water-containing mixed gas; after drying, pressurizing and heating, carrying out multi-stage conversion to obtain SO3 mixed gas; circulating absorption of fuming sulfuric acid; evaporating and removing impurities to obtain high-purity SO3 gas with the purity of 99.99% or above; carrying out liquefaction rectification to obtain an ultra-pure SO3 liquid with the purity of 99.9999% or above; after being gasified into ultra-pure SO3 gas, the ultra-pure SO3 gas is mixed with ultra-pure inert gas to obtain electronic-grade sulfuric acid absorption gas; circularly absorbing electronic-grade sulfuric acid; and filtering and outputting finished electronic-grade sulfuric acid. According to the invention, the electronic-grade sulfuric acid and the chemical reagent sulfuric acid can be simultaneously produced, and the comprehensive cost of investment and operation is reduced by 10-20%.

Provided herein are methods and systems for treating a sulfur dioxide-containing gaseous stream. The method includes combusting a tail gas in an excess of oxygen gas to yield a thermal oxidizer effluent containing sulfur dioxide and oxygen. The thermal oxidizer effluent is introduced to an oxidative catalytic converter to convert sulfur dioxide to sulfur trioxide, thereby forming an oxidized gas stream. The oxidized gas stream is routed to a quench tower and contacted with a dilute aqueous acid quench stream to yield sulfurous acid, hydrated sulfur dioxide, or both. The sulfurous acid or hydrated sulfur dioxide is oxidized with the excess of oxygen from the thermal oxidizer effluent to yield sulfuric acid.

A process method for treating lignin purification wastewater comprises a pretreatment section, a reaction section and a tail gas treatment section, the pretreatment section comprises an adjusting hardness removal unit, a tubular microfiltration unit, a bipolar membrane electrodialysis unit and a sludge thickening, dewatering and drying unit; the reaction section sequentially comprises a first-stage anaerobic unit, a second-stage anaerobic unit, an ozone catalytic oxidation unit and a BAF unit; the tail gas treatment section comprises an alkali liquor absorption unit and a methane storage unit. The modified anion exchange membrane is used for electrodialysis, so that most organic matters in the wastewater are intercepted in the desalinized solution, and most salt is converted into sulfuric acid and sodium hydroxide. In the process method, recycling and zero emission of wastewater are realized, waste gas is stored in a tank and can be used as fuel, salt is converted into sulfuric acid and sodium hydroxide products, and integral recycling of water, gas and solid is realized.

The invention relates to the technical field of sulfur purification equipment, and particularly discloses a liquid crude sulfur purification device which comprises a purification cylinder and a filter cylinder, the filter cylinder comprises a filter part and a plugging part, a plugging device is arranged in the purification cylinder, the plugging device comprises a filtrate plate, a plugging plate and a lifting mechanism, and filtrate holes are formed in the filtrate plate. The filtrate plate and the plugging plate are in sliding fit with the purification cylinder in the height direction of the purification cylinder, the filtrate plate and the plugging plate are attached to the peripheral face of the filter cylinder and the inner wall of the purification cylinder, and when the plugging plate drives the filtrate plate to descend, liquid below the filtrate plate passes through filtrate holes and filter holes and then flows to the position above the plugging plate; when the filtrate plate is located at the plugging part, the plugging plate and the filtrate plate are close to each other, the plugging plate is attached to the filtrate plate, liquid at the bottom of the purification barrel enters the position above the plugging plate, and impurities at the bottom of the purification barrel are discharged; the liquid crude sulfur purification device provided by the invention can reduce the phenomenon of waste of liquid sulfur.

The invention discloses a vanadium catalyst for sulfuric acid production and a preparation and use method thereof, and belongs to the technical field of catalysts. A catalyst formula and a preparation process are improved, a silicate aid is added to generate crystal silicon dioxide to regulate and control the structure of a diatomite carrier, and a tabletting molding process is adopted to replace an extrusion molding process, so that the strength and stability of the catalyst are improved, the abrasion is reduced, and the pulverization resistance is improved; the additive is added to modulate the active phase of the catalyst, the activity stability is improved, and the requirements of modern sulfuric acid production can be met. The catalyst produced by the technical scheme is uniform in active component distribution and high in mechanical strength, the stability is improved, the production requirements of sulfuric acid manufacturers can be better met, the operation stability of a sulfuric acid production device is improved, and remarkable economic benefits and social benefits are achieved.

The invention belongs to the technical field of environmental protection of pollutant recycling, and particularly relates to a process method for torsion loss of an ammonium sulfate section and a desulfurization section of coke oven gas. The method comprises the following related steps: (I) preparing a Ca (OH) 2 emulsion from CaO and water, reacting with coke oven gas to generate a first system containing CaS and CaCO3, introducing CO2 into the CaS emulsion to analyze H2S, and absorbing with NaOH to prepare Na2S so as to complete desulfurization and decarbonization; (II) hydrolyzing MgO to prepare a Mg (OH) 2 emulsion, reacting with flue gas SO2 and air to generate MgSO4, reacting with desulfurized and decarbonized coal gas to generate magnesium ammonium sulfate and regenerated Mg (OH) 2, and completing deamination; and (III) carrying out spraying reaction on HCN in the coal gas and NaOH through scrap iron, and filtering and evaporating to obtain ferrocyanide. The process treats pollution with waste, realizes medium circulation, has high product value, and solves the problems of corrosion and loss in the prior art.

The present invention discloses a preparation device for purifying sulfuric acid, which belongs to the field of concentrated sulfuric acid purification. The device comprises a purification box, a cover plate is provided above the purification box, a drive motor is provided on the cover plate, an output end of the drive motor is connected to an evaporation preparation tank via a drive member, an inner wall of the evaporation preparation tank is fixedly connected to an axis column, a steam collection hood is provided on the cover plate, a steam extraction pipe is provided on the top of the steam collection hood, the steam collection hood is connected to a plurality of resistive heating plates via a linkage adjustment member, and a suction fan blade located in the steam collection hood is connected to the top of the axis column via a transmission assembly. The present invention rotates the sulfuric acid in the evaporation preparation tank, and under the action of centrifugal force, the internal dilute sulfuric acid enters and flows outward under the action of centrifugal force. During the process of flowing outward, the dilute sulfuric acid is heated and evaporated by the resistive heating plate, thereby achieving rapid evaporation of more water in the low-concentration sulfuric acid solution, significantly improving the purification efficiency of sulfuric acid.

The invention discloses a flue gas acid making system and a negative pressure balanced flue gas acid making method, and belongs to the technical field of flue gas acid making, the system comprises an electric demister, a drying tower, a sulfuric acid circulating tank, a sulfur dioxide fan, a preheater and a converter. According to the invention, a multi-stage collaborative demisting process mode of connecting the electric demisters in parallel and then connecting the electric demisters in series with the wire mesh demister is constructed, so that deep removal of acid mist particles with different particle sizes, especially submicron-order acid mist particles is realized. According to the invention, through a leaked gas recycling and equipment on-line repairing integrated technology, SO2 unorganized dissipation treatment and acid making process parameter optimization are deeply coupled. The pressure relief joint control device is additionally arranged between the pneumatic butterfly valves at the inlet and the outlet of the faulted electric demister, and the negative pressure in the electric demister can be controlled through adjustment of the main pressure relief valve and interlocking with a fan frequency conversion system, so that non-stop maintenance is realized.

The utility model belongs to the field of sulfur melting kettle, specifically is a kind of sulfur foam sulfur melting kettle for blast furnace gas sulfur production, including kettle body, the top of kettle body is connected with kettle cover by bolt fixedly, the top of kettle cover is fixedly installed with connecting pipe;The utility model provides a kind of sulfur foam sulfur melting kettle for blast furnace gas sulfur production, by the setting of kettle body, kettle cover, connecting pipe, electric heat tracing band, heat-insulating cotton, second drive motor, second rotary rod, spiral blade and feed pipe, sulfur foam can be added to connecting pipe inside by feed pipe, sulfur foam added to connecting pipe inside can use electric heat tracing band to carry out preliminary heating, simultaneously, the output end of second drive motor can drive the rotation of the spiral blade fixedly installed on the surface of second rotary rod, the spiral blade of rotation can slowly drive the descending of heated sulfur foam, so as to make sulfur foam preliminary preheating, convenient for sulfur particle aggregation and settlement, simultaneously, after preheating, solubility of sulfide increases, and corrosion risk reduces.

This invention belongs to the field of lithium-ion battery technology, specifically relating to a composite cathode material for lithium-ion batteries and its preparation method. The composite cathode material consists of three parts: a cathode matrix material, a lithium replenishment material, and a catalyst material. The preparation method is as follows: (1) preparing a composite material of the cathode matrix material and the lithium replenishment material in situ; (2) dispersing the catalyst material on the surface of the composite material and forming a stable interface layer between the catalyst material and the lithium replenishment material. Through the method of this invention: the lithium replenishment material has both surface modification of the cathode matrix material and lithium replenishment of the negative electrode, simultaneously improving the battery's initial efficiency and cycle stability; introducing the catalyst material onto the surface of the lithium replenishment material in situ fixes the free O generated by the Li release from the lithium replenishment material, alleviating the battery swelling phenomenon and further improving the battery's cycle stability and safety; moreover, the preparation process is simple, the raw materials are cheap and readily available, the production cost is low, and it is easy to promote industrial production.

The invention provides a process for the preparation of sul furic acid and minerali zation of CO2 from industrial gases, comprising : CO2- absorption step, comprising continuously sparging C02- containing gas through an aqueous solution of ammonia in a first reactor, or continuously sparging C02-containing gas and ammonia gas through water, to form [ (NH4 ) 2CO3 / NH4HCO3 ] solution; continuously withdrawing [ (NH4 ) 2CO3 / NH4HCO3 ] solution from the first reactor and providing said [ (NH4 ) 2CO3 / NH4HCO3 ] solution, after it has been optionally cooled, to a second reactor, wherein NH3 and CO2-bearing gas stream discharged from the first reactor is fed to the second reactor, thereby producing (NH4 ) 2CO3 aqueous solution in the second reactor and releasing an essentially NH3 and CO2- free gas from the second reactor; CO2-minerlai ztion step, comprising reacting the (NH4 ) 2CO3 in water with calcium sul fate [ CaSO4 ], to form a solution of ammonium sul fate [ (NH4 ) 2SO4 ] and precipitate solid calcium carbonate [ CaCO3 ], separating CaCO3 from said solution and recovering ammonium sulfate crystals from the solution; and H2SO4- format ion step, comprising thermally decomposing the (NH4 ) 2SO4 to give sul furic acid and supplying a stream of ammonia released from the thermally decomposed (NH4 ) 2SO4 to the CO2-absorption step.

The invention discloses a molybdenum disulfide nanosheet / nitrogen-doped bamboo-like carbon fiber tube / sulfur composite material and a preparation method thereof, a lithium-sulfur battery positive electrode and a lithium-sulfur battery, the preparation method comprises the following steps: mixing melamine and aluminum, under the protection of inert gas, reacting for 0.5-4 hours at a high temperature of 900-1500 DEG C, soaking the obtained reactant in an inorganic acid solution for 2-24 hours, and drying to obtain the molybdenum disulfide nanosheet / nitrogen-doped bamboo-like carbon fiber tube / sulfur composite material. Then dispersing the nitrogen-doped bamboo-like carbon fiber tube material, thioacetamide, sodium molybdate and urea into a solvent, carrying out solvothermal reaction, calcining the obtained reactant in a reducing atmosphere, and finally carrying out sulphitation; the composite material is characterized in that the surface of a hollow bamboo-like nitrogen-doped bamboo-like carbon fiber tube is coated with a flaky molybdenum disulfide nanosheet, sulfur is loaded on the flaky molybdenum disulfide nanosheet, the composite material is used as an active material to prepare a lithium-sulfur battery positive electrode, and then a lithium-sulfur battery is assembled. The lithium-sulfur battery has relatively good cycling stability and rate capability.

The application discloses a flue gas recovery system in a calcination zinc sulfide process and relates to the technical field of zinc sulfide production. The flue gas recovery system comprises, which are connected by pipelines in sequence, a waste heat recovery boiler, a bag-type dust collector, an electrostatic precipitator, a mixed converter, a cyclone separator, an absorption tower and a spray tower. The mixed converter comprises an outer cavity, an inner cavity and a tail gas inlet pipe. The tail gas inlet pipe is connected with one end of the inner cavity. The outer cavity is provided with a medium inlet at the end far from the tail gas inlet pipe. The outer cavity is provided with a medium outlet at the end far from the medium inlet. The inner cavity is provided with a tail gas outlet pipe at the end far from the tail gas inlet pipe. An oxygen inlet and a powder inlet are installed on the side wall of the inner cavity. The inner cavity is internally provided with a turbulence column. Under the guidance of the turbulence column, the tail gas, oxygen and catalyst powder can be fully mixed, which can accelerate the reaction speed of sulfur dioxide and oxygen in the tail gas, thereby accelerating the generation speed and quality of sulfur trioxide.

The utility model belongs to the technical field of sodium sulfide concentration, and particularly relates to a sodium sulfide concentration device which comprises a protective heat-insulating shell, an equipment main body arranged in the protective heat-insulating shell, a heating plate fixedly mounted on the inner wall of the equipment main body, a feeding hole formed in the top of the protective heat-insulating shell, and a mounting frame fixedly mounted on the top of the protective heat-insulating shell, a base is fixedly installed at the bottom of the protective heat preservation shell, a connecting groove is formed in the inner side of the base, and a filtering box is arranged at the bottom of the protective heat preservation shell. According to the device, the mounting frame, the hydraulic cylinder, the motor, the rotating rod and the scraping plate are matched for use, lifting and rotating adjustment can be conducted on the rotating rod and the scraping plate, and comprehensive cleaning work can be conveniently conducted on the inner wall of the device body; and the inner wall of the equipment main body can be conveniently, rapidly and effectively cleaned, and cleaning is more thorough.

The invention discloses a low-energy-consumption method for preparing high-metallization-ratio reduced iron blocks from laterite-nickel ore high-pressure acid leaching residues, and belongs to the technical field of metallurgical solid waste recycling. The method comprises the following steps: performing low-temperature reduction roasting on the laterite-nickel ore high-pressure acid leaching residues in a reducing atmosphere to obtain primary roasted sand; carrying out high-temperature desulfurization roasting on the primary roasted product in a non-reactive atmosphere to obtain a final roasted product; and carrying out hot press molding on the final roasted product to obtain the reduced iron block. According to the method, the technological process of reduction, desulfurization and hot pressing is adopted, the method has the advantages that the process is compact, energy consumption is low, iron and sulfur elements are easy to recover and the like, the laterite-nickel ore high-pressure acid leaching residues can be efficiently converted into high-quality reduced iron blocks with high strength, low impurity and high metallization ratio, high-concentration SO2 meeting the acid making requirement is synchronously obtained, and the method is suitable for industrial production. According to the method, large-scale and high-valued clean utilization of iron and sulfur resources in the laterite-nickel ore high-pressure acid leaching residues is achieved, and the method is mild in technological condition and stable in operation and has a good industrial application prospect.

The stainless steel acid distributor comprises an acid inlet barrel, an acid distribution assembly and an acid inlet pipe, the acid inlet barrel extends in the vertical direction and is fixed to a tower barrel of a dry absorption tower, the acid distribution assembly is rotationally hung at the lower end of a fixed barrel, an acid inlet is formed in the acid inlet barrel, and the acid inlet pipe is communicated with the acid inlet barrel through the acid inlet; the acid distribution assembly comprises a main pipe rotationally mounted on the acid inlet pipe and a branch pipe fixed on the main pipe, and spraying holes are formed in the branch pipe; blades are installed in the main pipe, sulfuric acid can enter the acid inlet barrel through the acid inlet pipe, and under pushing of the sulfuric acid, the blades can drive the acid distribution assembly to rotate. The sulfuric acid entering the acid inlet barrel pushes the acid distribution assembly to rotate through the blades, so that the sulfuric acid sprayed out of the branch pipes can spray the whole end face of the filler area, the distribution uniformity of the sulfuric acid is improved, the height of the filler area tends to the designed height, the tower resistance is reduced, and the conveying cost of gas is reduced.

The application belongs to the technical field of solid waste resource utilization, and specifically discloses a method and device for preparing silicon-calcium aggregate, sulfuric acid and CO2 by phosphogypsum oxygen-rich high-temperature decomposition. The method uses the adsorption method to obtain pure nitrogen products and oxygen-rich combustion-supporting gas, and provides different reaction temperatures and reaction atmospheres for different reaction stages of the rotary kiln reactor through the multi-point combustion mode, thereby ensuring the controllable high-temperature environment and atmosphere in the kiln. The method improves the combustion efficiency, greatly reduces the amount of flue gas after decomposition, effectively improves the concentration of SO2 in the flue gas and the efficiency of the subsequent sulfuric acid preparation system, and realizes CO2 emission reduction and resource utilization by using the CO2-rich tail gas of the sulfuric acid preparation system for adsorption recovery. The application also provides a device for realizing the method, which combines gas adsorption, oxygen-rich combustion and rotary kiln multi-point combustion equipment, thereby ensuring the effective realization of the process.

The utility model discloses a split burner type waste acid cracking furnace which comprises a combustion chamber, a feeding pipe is fixedly arranged on the left side of the combustion chamber, two groups of burners are fixedly arranged above the combustion chamber, the lower part of the combustion chamber is connected with a first cracking chamber through a partition plate, and the lower part of the first cracking chamber is connected with a second cracking chamber through a partition plate. The combustion chamber of the split burner type waste acid cracking furnace forms a suction structure with the connecting pipe under the driving of the fan, and the connecting pipe forms a communicating structure with the first cracking chamber and the second cracking chamber through the concave air inlet pipe, the spraying arm and the spraying head respectively, so that high temperature generated in the combustion chamber can be uniformly introduced into the first cracking chamber and the second cracking chamber; the first cracking chamber of the device and the second cracking chamber form a communicating structure through the through holes in the partition plate, and therefore it is guaranteed that the waste acid processed in the first cracking chamber can enter the second cracking chamber to be subjected to secondary processing.

The invention discloses a method for preparing a soil conditioner from sulfur-containing tailings, a multifunctional soil conditioner is prepared through aging pretreatment, high-temperature activation, sulfur resource recovery and nutrient synergistic blending, and the method is suitable for ecological restoration of mining areas and degraded soil improvement. SO2 is efficiently oxidized and absorbed and converted into sulfuric acid through a two-stage absorption system and a spraying liquid with a specific formula, the sulfuric acid is subsequently used for tailings neutralization, closed-loop circulation of sulfur elements from tailings waste to product components is achieved, and the utilization rate of sulfur resources is greatly increased; meanwhile, unstable sulfides can be effectively decomposed in the high-temperature calcination process, so that part of heavy metals are converted into more stable forms, and the environmental risk is eliminated; venturi washing waste liquid and absorption tower circulating liquid are recycled to respective systems, so that the wastewater generation amount and the fresh water consumption are remarkably reduced.

The invention belongs to the technical field of waste acid treatment, and particularly relates to an efficient concentration process for waste acid in phenylenediamine production. According to the high-efficiency concentration process for the waste acid generated in phenylenediamine production, multi-stage concentration and resource recycling are combined, impurities are removed through pretreatment of the composite adsorbent, and the adsorbent is recycled and regenerated through magnetic separation; according to the invention, waste acid is extracted from 70-75% to 95.5-96% through first-stage vacuum concentration, second-stage vacuum concentration and pot-type three-stage concentration, and the waste acid can be reused in a second-stage nitrification process, so that cyclic utilization is realized, and the consumption of raw materials is reduced. According to the process, pot-type concentrated high-temperature tail gas is used as a first-stage vacuum concentration heat source to recover waste heat, and external energy consumption is reduced; diluted acid water is separated through a pervaporation membrane, recycled water is used for washing, concentrated dilute acid is recycled for pretreatment, closed cycle emission reduction is formed, and the requirements for green, low carbon and circular economy are met. Meanwhile, by means of composite adsorbent magnetic separation, corrosion-resistant material application and an efficient composite membrane technology, the system stability and efficiency are improved, the service life of equipment is prolonged, and the maintenance cost is reduced.

This invention discloses a low-temperature melting and filtering device for waste sulfur and its operating method. The device includes a crushing device, a screening device, a conveying device, and a sulfur melting kettle connected in sequence. The sulfur melting kettle is equipped with a heating device and a cooling device. The kettle lid is equipped with a feed valve, a nitrogen filling valve, a tail gas valve, a pressure gauge, a level gauge, a first thermometer, and a pressure relief valve. The nitrogen filling valve is connected to a nitrogen source through a gas pipe. The tail gas valve is connected to an absorption tower through a pipeline, and a first exhaust pump is installed on the pipeline. The bottom of the kettle has a discharge hole. The pressure relief valve is connected to a waste liquid collection tank externally through an overflow pipe. The top of the conveying device is connected to a feed auger, the top of the feed valve is connected to a temporary storage cylinder, and the top of the temporary storage cylinder is connected to the feed auger. The bottom of the kettle has a hinged discharge gate that can seal the discharge hole. The discharge gate has a liquid extraction hole, the top of which has a filter screen, and the bottom of which is connected to a discharge valve. The device and method of this invention have the characteristics of high thermal efficiency and sufficient safety redundancy.