79 results about "Dilute acid" patented technology

The invention relates to the technical field of wet-process phosphoric acid, and discloses a wet-process phosphoric acid grading and arsenic removal treatment method and system, and the system can be switched between a parallel grading treatment mode and a series depth treatment mode through flow control; in the parallel mode, the two arsenic removal reaction tanks operate independently to respectively treat different raw materials and produce desulfurized acid for industrial monoammonium and low-arsenic dilute phosphoric acid for high-phosphorus compound fertilizer, the low-arsenic dilute phosphoric acid is mixed and blended with untreated dilute acid and then concentrated, qualified products are obtained with the minimum treatment capacity, and the cost is remarkably reduced; in the series connection mode, raw materials sequentially flow through the two tanks to be deeply purified, and single high-quality phosphoric acid is produced; the two modes are both integrated with efficient filter pressing units, solid-liquid separation is carried out on arsenic-containing thick slurry generated by arsenic removal, and phosphorus resource recovery and arsenic pollution control are achieved; the device has production flexibility and deep purification capacity, perfectly meets the requirements of raw material fluctuation and multiple products, and thoroughly solves the problem of arsenic slag disposal.

A production process of electronic grade molybdenum dichloride dioxide comprises the following steps: S1, pretreatment: contacting molybdenum trioxide with a dilute acid solution at a low temperature for pickling to remove alkaline impurities and soluble metal impurities adsorbed on the surface, and drying for later use after washing; s2, wet synthesis: in an inert gas atmosphere, reacting the molybdenum trioxide subjected to acid pickling in the step S1 with concentrated hydrochloric acid of which the mass is 4-5 times of that of the molybdenum trioxide at 80-100 DEG C, and after the reaction is finished, evaporating and concentrating in a high-temperature chlorine atmosphere to generate a crude product of dichloromolybdenum dioxide; s3, primary sublimation purification; s4, complexing and decomplexing purification; and S5, secondary sublimation purification: using a quartz sublimation tower to carry out vacuum sublimation on the secondary decomplexed molybdenum dichloride obtained in the step S34, and collecting sublimation condensate to obtain the electronic grade molybdenum dichloride. The final product purity of the production process is greater than or equal to 6N, and the process can be used for large-scale production.

The utility model discloses an evaporator and a pickling facility low-corrosion treatment device thereof. A concentrated acid tank, a first connecting pipe, a diluted acid tank and a second connecting pipe are used for a pickling process and can also be used for alkali neutralization, water washing and blow-drying. After pickling is completed, the acid storage tank can neutralize residual acid, the pipeline is neutralized by alkali and / or flushed by neutralizing liquid, and under the condition that the pump body design is saved, waste acid discharged by pickling of the evaporator can be returned to the tank for treatment, so that environmental acid pollution is avoided; the reduction evaporator and pickling equipment thereof can be further washed and blown off, so that the corrosion risk is greatly reduced; the service life of a tank pipeline is prolonged by more than 50%, the overhaul cost is reduced, the leakage condition is reduced, and the safety coefficient is improved.

The invention relates to the technical field of pesticide production, and particularly discloses a preparation process of glufosinate-ammonium intermediate 3-(methyl hydroxyl phosphonyl) propionaldehyde. The preparation method comprises the following steps: 1, carrying out addition reaction on diethyl methylphosphonite and acrylic acid in absolute ethyl alcohol to generate 3-[ethyoxyl (methyl) phosphonyl] propionate; in the second step, 3-[ethyoxyl (methyl) phosphonyl] propionate is subjected to a hydrosilylation reaction in an oriented mode, and 3-triethyl siloxy-3-ethyoxyl propyl methyl ethyl phosphonate is generated; and 3, carrying out a simple dilute acid hydrolysis reaction to obtain the 3-(methyl hydroxyl phosphonyl) propionaldehyde. According to the method, a three-step reaction route of addition-hydrosilylation-hydrolysis is adopted, and the acrylic acid is used for replacing the traditional high-toxicity raw material acrolein, so that the toxicity risk is avoided from the source, the yield of the target glufosinate-ammonium intermediate is remarkably improved, the total yield of the three-step reaction can reach 95% or above, and the method is suitable for industrial production. And an efficient and green brand-new technical scheme is provided for large-scale production of glufosinate-ammonium.

The application discloses a cleaning method of a cauldron for preparing aluminum trihydride, which comprises the following steps: (1) under an inert gas atmosphere, adding a polyhalogenated hydrocarbon solvent and an inorganic salt abrasive into the cauldron, and stirring intensively to grind off the wall-bonding substances in the cauldron; (2) emptying the cauldron, and slowly feeding a buffer solution into the cauldron through a bottom pipe in a vacuum-extraction mode, so that the buffer solution is immersed into the cauldron from the bottom of the cauldron; and (3) sequentially using dilute alkali, dilute acid and water to completely immerse the wall-bonding layer, and then washing the cauldron with water. The method can safely and effectively remove the wall-bonding substances on the cauldron.

The invention provides a method for detecting and analyzing heavy metal chromium in high-aluminum ore and red mud, and belongs to the field of mineral analysis and detection. The method comprises the following steps: melting a mixture of a sample to be detected and a strong alkaline flux to obtain a melt; extracting and dissolving the melt by using a dilute acid solution to obtain a leaching solution; a strong oxidant and a catalyst are added into the leachate, so that chromium ions in the leachate are oxidized into hexavalent chromium ions, and hexavalent chromium conversion liquid is obtained; adding an alkali carbonate solution into the hexavalent chromium conversion solution to adjust the pH value of the hexavalent chromium conversion solution to 8-10 to obtain a mixed solution; filtering the mixed solution to obtain a chromium-containing filtrate; and quantifying the total chromium content in the chromium-containing filtrate by adopting a spectrophotometric method. The detection and analysis method provided by the invention can ensure that chromium existing in lattices of the high-aluminum ore and red mud sample is completely released, and main matrix interference elements such as aluminum, iron, calcium and magnesium in the sample can be effectively separated, so that accurate determination of the total chromium content in the to-be-detected sample is realized.

The application discloses a preparation process of electronic-grade trans-1,2-cyclohexanediaminetetraacetic acid. The preparation process takes industrial-grade 1,2-cyclohexanediamine as raw material, reacts the 1,2-cyclohexanediamine with electronic-grade organic acid to generate a water-soluble salt, crystallizes at 0-30 DEG C, filters out the crystal to reserve the filtrate, adds an alkaline solution to the filtrate, then adds a polar organic reagent to extract, directly adds an aqueous bromoacetic acid solution to the oil phase to react, after the reaction is completed, adds electronic-grade dilute acid to precipitate trans-1,2-cyclohexanediaminetetraacetic acid until the PH of the system is less than or equal to 2, filters and reserves the solid, washes with pure water, and electronic-grade trans-1,2-cyclohexanediaminetetraacetic acid is obtained. The method has a clear process route, can effectively remove metal ion impurities in the synthesis process, the obtained trans-1,2-cyclohexanediaminetetraacetic acid product has high purity, can be used for preparing high-end semiconductor cleaning liquid, and meets the strict requirements of advanced processes on the purity of cleaning chemicals.

The application provides a preparation method of dydrogesterone, which comprises the following steps: performing a selective epoxidation reaction on a compound I in a first solution containing meta-chloroperoxybenzoic acid and hydrogen peroxide to obtain a compound II; the content of the meta-chloroperoxybenzoic acid in the first solution is more than 1 times of the amount of substance of the compound I; performing a reduction reaction on the compound II under the action of hydrogen and a catalyst to obtain a compound III; performing a hydrolysis reaction on the compound III in a dilute acid solution, and then performing a hydroxyl elimination reaction on the compound III in a second solution to obtain the dydrogesterone; the structural formulae of the compound I, the compound II, the compound III and the dydrogesterone are as follows:; and. The preparation method has less by-products and a higher reaction yield.

A preparation method of an infrared detector chip based on a gold-free electrode relates to the technical field of infrared detection, and comprises the following steps: preparing a required to-be-metallized infrared detector wafer, sputtering and depositing a gold-free electrode film layer on the to-be-metallized infrared detector wafer; depositing a gold-free electrode film layer with a certain thickness on the surface of the wafer by setting parameters of sputtering power, gas flow and heating temperature, and completing preparation of a metal electrode after a stripping process; the infrared detector wafer after electrode preparation is subjected to dilute acid solution post-treatment, an oxide layer and impurities on the surface of the metal electrode are removed through a dilute acid solution, and preparation of the infrared detector wafer is completed; and finally, cutting the infrared detector wafer to complete the preparation of the infrared detector chip. According to the invention, good ohmic contact between the electrode and an infrared focal plane detector wafer and good flip-chip interconnection between the electrode and high-purity indium are realized, and the electrode is used as a low-cost choice for replacing a system taking Au as a core electrode.

The utility model discloses an iron removal device for white corundum, which belongs to the field of white corundum iron removal, and comprises a bottom plate, the top of the bottom plate is fixedly connected with a white corundum iron removal reaction box, one side of the white corundum iron removal reaction box is fixedly connected with a dilute acid solution storage box, and the top of the dilute acid solution storage box is fixedly provided with a pump body; one side of the pump body is fixedly connected with a liquid guide pipe, and one end of the liquid guide pipe extends into the white corundum iron removal reaction box; through the arrangement of the feeding and discharging mechanism, white corundum subjected to iron removal can be automatically fished out from the interior of the white corundum iron removal reaction box, an operator can be effectively prevented from making contact with a dilute acid solution, the operator can conduct discharging more conveniently, and feeding and discharging integration is achieved; and an operator can clean and drain the deironed white corundum more conveniently, and the operator can treat the white corundum more conveniently in the follow-up process.

The invention discloses an absorbable monofilament suture and a preparation method thereof, and the preparation method comprises the following steps: S1, dissolving chitosan in a dilute acid solution to form a spinning solution; s2, sequentially carrying out filtering treatment and vacuum defoaming treatment on the spinning solution; s3, the spinning solution treated in the step S2 is extruded into a coagulating bath through a spinning component, and nascent fibers are formed; s4, carrying out water washing treatment on the nascent fiber; s5, immersing the nascent fiber treated in the step S4 into a polycarboxylic acid solution to carry out an ionic cross-linking reaction; s6, the fibers subjected to the ionic cross-linking reaction in the step S5 are sequentially subjected to water washing treatment and drying treatment, the absorbable monofilament suture is obtained, the mechanical properties such as dry-state holding stress and the like of the finally obtained monofilament suture are synergistically and remarkably improved, use of a toxic chemical cross-linking agent is avoided, and the production cost is reduced. And the suture is ensured to finally have good biocompatibility and controllable degradation performance.

The invention relates to the technical field of resource utilization of metallurgical and chemical wastes, in particular to a method for neutralizing waste acid and enriching ferrovanadium from vanadium-containing steel slag. The method comprises the following steps: S1, grinding the vanadium-containing steel slag into fine powder, and adding water according to a liquid-solid ratio of 1g: (1-1.5) ml to prepare slurry; s2, preparing the sulfuric acid process titanium dioxide byproduct waste acid and the acid wastewater into dilute acid with the concentration of 5-15%; s3, dilute acid is added into the slurry, the pH is controlled to be 6-8, the reaction temperature is larger than or equal to 50 DEG C, and continuous stirring reaction is conducted; s4, after the reaction is completed, heating to 90 DEG C or above, and keeping boiling for 30-60 minutes; and S5, flotation separation is conducted, and gypsum slag and an iron-rich vanadium material are obtained.

The invention belongs to the field of biomass energy utilization, and particularly relates to a method for preparing high-value dehydrated sugar through rapid pyrolysis based on extremely dilute acid high-temperature modification. The method comprises the following steps: by taking palm plant seed waste as a raw material, carrying out boiling-washing modification at a temperature close to a boiling point by using an acid aqueous solution with extremely dilute concentration, preferably further carrying out cold plasma discharge modification treatment, and then carrying out rapid pyrolysis under an anaerobic condition at 350-450 DEG C, and condensing the obtained pyrolysis steam to obtain a liquid product rich in levomannan (LM, 1, 6-anhydro-beta-D-mannopyranose). According to the method, ash can be effectively removed, the reaction activity of the raw materials is improved, high-purity enrichment of LM is promoted, and a technical approach is provided for high-value utilization of palm plant seed waste.

The application belongs to the technical field of water treatment, and particularly discloses an acid recovery device. The acid recovery device comprises an acid separator and acid concentration electrodialysis. The acid separator is sequentially arranged and placed by a positive charge microporous semi-permeable membrane, a negative charge fibrous filler, a positive charge microporous semi-permeable membrane, a raw material chamber separation net and a positive charge microporous semi-permeable membrane. The components arranged in this way can be arranged in multiple ways to realize more efficient treatment. Dilute acid from the acid separator enters the acid concentration electrodialysis component for treatment. The acid recovery device has the advantages of fast diffusion speed, high salt concentration of waste acid, the ability to treat waste acid with high salt concentration, high recovery rate and the like.

The invention discloses a starch flocculation characteristic detection method based on enzymatic liquefaction and visual identification, and relates to the technical field of starch quality detection and performance evaluation.The starch flocculation characteristic detection method comprises the steps that firstly, a sample is prepared, a to-be-detected starch sample and tap water are mixed according to a preset mass-volume ratio, and oscillation and shaking up are conducted to form a starch milk suspension; adjusting the system, namely adjusting the pH value of the starch emulsion suspension to 5.2-6.5 by using a dilute acid or dilute alkali solution; carrying out enzymolysis and liquefaction, adding a proper amount of amylase solution into the starch milk suspension with the adjusted pH value, and continuously oscillating or stirring under a heating condition until the system is completely liquefied; cooling, standing and observing, naturally cooling the completely liquefied liquid to room temperature, standing, observing whether floccules are generated on the liquid level or the solution in the standing process or after standing, and evaluating the aggregation state of the floccules; and finally judging a result. Compared with the prior art, the method has the advantages of rapidness, intuition, low cost, strong simulation, good discrimination and flexibility.

The invention discloses a method for rapidly detecting carbon disulfide in a paraffin remover and inhibitor. The method comprises the following steps: 1, preparing a potassium hydroxide ethanol solution; 2, putting the paraffin remover or paraffin inhibitor to be detected into the potassium hydroxide ethanol solution, and uniformly stirring to obtain a detection intermediate solution; 3, acidifying hydrogen peroxide with colorless dilute acid to obtain an acidic hydrogen peroxide solution; 4, placing the dried starch potassium iodide test paper in an acidic hydrogen peroxide solution, waiting for 30 seconds when the starch potassium iodide test paper turns blue and the color does not change any more, and taking out the blue starch potassium iodide test paper; and 5, putting blue starch potassium iodide test paper into the detection intermediate solution in the step 2, and judging whether the to-be-detected paraffin remover or paraffin inhibitor contains CS2 or not according to whether the blue starch potassium iodide test paper fades or not. According to the detection method disclosed by the invention, whether the paraffin remover or the paraffin inhibitor contains CS2 or not is qualitatively judged through color difference of color development reaction, and the method has the advantages of simplicity, high detection efficiency, wide application range and the like.

The invention discloses a titration acid adding structure and a dyeing machine thereof, relates to the technical field of dyeing and finishing equipment, and solves the technical defects that the acid control mode of the traditional dyeing machine cannot accurately control the pH value, or two sets of central acid adding barrels are needed, manual dilution is needed, the occupied area is large, the operation is inconvenient, automatic control cannot be realized and the like. The bottom of the self-flowing acid storage barrel is connected with an acid adding valve; a nozzle of the acid adding valve is internally provided with a replaceable throttling joint with different hole diameters; a backflow pipeline is further arranged on the feeding barrel; the outlet of the material pump is also connected with a filling pipeline of the main cylinder; and a quantitative follow-up valve is arranged on the filling pipeline. A user does not need to prepare one more diluted acid barrel, dilution is not needed, and full-process automation of acid control can be truly achieved on the premise that the acid adding control precision is guaranteed.

The utility model discloses an edible vegetable oil degumming device and relates to the technical field of edible vegetable oil processing. An edible vegetable oil degumming device comprises a fixing frame, a degumming barrel is fixedly connected to the fixing frame, a stirring shaft is rotationally connected to the center position in the degumming barrel, a driving motor is fixedly connected to the middle of the top end of the degumming barrel, and an output shaft of the driving motor is fixedly connected with the stirring shaft. And the degumming barrel is provided with a suction assembly for sucking oil at different depths. A certain amount of dilute acid solution is added into the degumming barrel through cooperation of the quantifying barrel and the blocking block, colloidal substances such as phospholipid in crude oil absorb water and expand to form floccules through stirring of the stirring shaft, when the crude oil stands and settles, the heavier floccules naturally sink to the bottom of the degumming barrel, and upper-layer clear oil is extracted through the suction pipe and the extension pipe. And the extension pipe slides up and down to adjust the height, so that the suction depth can be flexibly adjusted according to the actual sedimentation condition without waiting for complete sedimentation of floccules, and the degumming effect and the production efficiency are improved.

A pretreatment method for the analysis of trace impurities in magnesium pyrocene involves placing a precisely weighed, dried sampling bottle and sampling device into an inert atmosphere chamber. Magnesium pyrocene is then placed into the sampling bottle using the sampling device, the bottle cap is tightened, and the inert atmosphere chamber is removed. The total weight of the sampling bottle and the magnesium pyrocene contained therein is accurately weighed. A 5% (w / w) dilute acid solution is then added dropwise to a Class 100 cleaning table to allow the reaction to proceed. After the reaction slows down, a small amount of the 5% (w / w) dilute acid solution is added to fully dissolve the sample. The solution is first heated at a low temperature, and the sample on the inner wall of the bottle is rinsed clean with the 5% (w / w) dilute acid solution. The temperature is then increased to allow for a complete reaction, and the acid is removed until nearly dry. The substance in the sampling bottle is then dissolved with the 5% (w / w) dilute acid solution to prepare the corresponding test solution for subsequent detection. This invention solves the problems of complex processes and the easy introduction of other trace impurities in existing technologies.

The invention discloses a method for preparing high-whiteness superfine anhydrous gypsum by purifying industrial by-product gypsum, which comprises the following steps: by taking the industrial by-product gypsum as a raw material, firstly, carrying out deep purification pretreatment to obtain gypsum of which the whiteness is greater than or equal to 55% and the content of CaSO4. 2H2O is greater than or equal to 95%; and sequentially carrying out dilute acid dissolution, organic matter extraction and crystal transformation whitening treatment on the pretreated gypsum to obtain the high-whiteness superfine anhydrous gypsum with the whiteness of more than or equal to 90%. The obtained high-whiteness superfine anhydrous gypsum is high in whiteness, finer in fineness and controllable in crystal form and crystal appearance, and compared with anhydrous gypsum obtained through a calcination method, the high-whiteness superfine anhydrous gypsum is low in energy consumption, small in carbon emission, high in benefit and suitable for wide popularization and implementation.

The utility model relates to the technical field of dilute acid tanks, in particular to a vacuum dilute acid tank for stevia rebaudiana production, which comprises a storage component capable of storing dilute acid solution in vacuum, a displacement component convenient for the dilute acid tank to move is arranged at the bottom of the storage component, and a uniform mixing component for stirring and uniformly mixing the dilute acid solution is arranged on one side of the storage component; wherein the uniform mixing assembly comprises a main shaft, and the side part of the main shaft is fixedly inserted into the centers of the two groups of mounting frames. According to the utility model, by using the uniform mixing component, the raw materials are stirred and mixed before being discharged, so that the stirring of dilute acid liquid is enhanced, the discharged dilute acid liquid is effectively prevented from precipitating, and the normal effect of the dilute acid liquid is further ensured. By using the storage assembly, negative pressure is formed in the tank body, under the action of the one-way valve, external air cannot enter the tank body through the one-way valve, reaction between the air and the acid liquid is effectively reduced, and then the purity of the acid liquid is guaranteed.

The invention relates to a preparation process of a low-wire-consumption diamond wire for wafer cutting, and belongs to the technical field of diamond wire processing. The diamond wire is soaked in a 10-15% sodium hydroxide solution for 3-5 min; taking out and soaking in a dilute acid solution for 1-2 minutes; immersing the bus into a 3-5% sulfuric acid solution for 30-60 seconds, taking out the bus, and washing the bus with clear water for 3-5 times; and at the constant temperature of 50-60 DEG C, applying 1-4 A / dmcurrent density to electroplate a pre-plating layer on the outer surface of the bus. Oil stains on the surface of the bus are removed through alkali washing, then dilute citric acid washing activation is carried out, then dilute sulfuric acid washing micro-etching is carried out on the outer surface of the bus, compared with traditional simple acid washing or alkali washing, the binding force between a pre-plating layer and the bus is effectively increased, the plating layer is effectively prevented from falling off, meanwhile, a smooth, uniform and good-conductivity surface is provided for follow-up sand feeding, and the service life of the bus is prolonged. And subsequent uniform adhesion of wear-resistant particles is facilitated.

The invention relates to the technical field of pesticides, in particular to a continuous synthesis process and device for a prothioconazole intermediate, and the continuous synthesis process at least comprises the following steps: synthesizing hydrazone from a BL-6 oil phase and formaldehyde in a continuous formation hydrazone reactor; synthesizing a BL-7 mixed phase from hydrazone, a thiocyanate aqueous solution and a dilute acid aqueous solution in a continuous ring-closing static tubular reactor; carrying out phase separation on the BL-7 mixed phase in a continuous phase separation reactor to obtain a BL-7 oil phase and a salt water phase; and the BL-7 oil phase is directly subjected to synthesis of prothioconazole without desolvation. Precise preparation of the key intermediate BL-7 is achieved through the modular continuous flow reaction system, compared with a traditional kettle type process, the continuous production period is shortened to 1 / 6 of that of an original process, the raw material utilization rate is increased by 20%, the three-waste generation amount is reduced by 50%, the risk of enrichment of highly toxic substances such as thiocyanic acid in the traditional process is effectively avoided, and the modular continuous flow reaction system is more suitable for industrial production.

The utility model discloses a dilute acid purification and concentration treatment system which comprises a tubular filter, a membrane distillation system and a flash tower, the membrane distillation system comprises a raw material tank, a concentrated water tank, a membrane distillation assembly, a vacuum pump and a cold circulation system, the flash tower is connected with a heat circulation system, and the membrane distillation assembly comprises a membrane evaporation assembly and a membrane condensation assembly. The bottom of the flash tower is fixedly connected with a concentrated acid pipeline, an efflux pump and an online sulfuric acid concentration meter are arranged on the concentrated acid pipeline, the other end of the concentrated acid pipeline is communicated with a concentrated water tank, and the cold circulation system comprises a cooling water inlet pipeline, a cooling water return pipeline, a circulation water tank and a vacuum system heat exchanger. By means of the structure, removal of impurities in the dilute sulfuric acid and concentration and recycling of the dilute sulfuric acid are achieved, the dilute sulfuric acid can be economically and efficiently purified and concentrated, and the problems that in the waste acid and dilute acid treatment process, the environment is affected, and resources are wasted are solved.

The invention belongs to the technical field of silicon-based material synthesis, and particularly discloses nano silicon prepared on the basis of metal silicon alloy and a preparation method and application of the nano silicon. The preparation method comprises the following steps that concentrated acid and deionized water are used for preparing dilute acid, metal silicon alloy powder is dispersed into the dilute acid, and a mixed solution is obtained; adding an antioxidant, uniformly stirring and mixing, carrying out a first reaction until bubbles are generated, gradually adding concentrated acid and a dispersing agent, and carrying out a second reaction until no gas is generated, so as to obtain a mixture; filtering, washing and drying the mixture to obtain porous silicon; and placing the porous silicon in a solvent, adding a dispersing agent and an antioxidant, uniformly mixing, and crushing to obtain the nano silicon particles. The nano silicon prepared by the method has the advantages of low cost, simple process, low oxygen content, good dispersity and the like; the prepared half cell has the advantages of relatively high capacity and first efficiency and the like; and as the size is nanoscale, the cycle performance is also improved.

The invention provides a method for purifying fishing net regenerated nylon, which comprises the following steps of: removing metal impurities and inorganic halide salt on the surface by dilute acid, and reacting halogen compounds in nylon melt under the action of an alkaline dehalogenation agent and a dehalogenation catalyst under the strong shear mixing action of a screw extruder to obtain the fishing net regenerated nylon. Inorganic halogen salt and organic halogen compounds which are adsorbed or wrapped in the fishing net regenerated nylon are removed, so that effective removal of halogen is realized; and on the other hand, the temperature of each section in the screw extruder is meticulously regulated and controlled, so that the halogen removal effect is ensured on one hand, and the mechanical property of nylon is ensured not to be reduced on the other hand. According to the method, the halogen removal rate can reach 90% or above, and the mechanical property retention rate of the prepared nylon can reach 90% or above.

The utility model discloses a kind of purification devices for reducing arsenic in dilute acid, by primary high-efficiency scrubber, gas cooling tower, secondary packing tower, accident high-level water tank, dilute acid settling tank, purification pressure filter, purification filtrate tank, primary reaction tower, secondary reaction tower, tertiary reaction tower, pump pit, reaction tower pressure filter, reaction tower filtrate tank composition, using reaction tower to increase the maximum circulating quantity of primary high-efficiency scrubber, through high-concentration sulfur dioxide reduction settlement pentavalent arsenic, effectively solve the problem of high arsenic content in dilute acid, high dilute acid processing cost, high resistance of primary high-efficiency scrubber, tower cleaning frequency, large overhaul workload. The device is safe and environmentally friendly, has low failure rate, can adapt to high-arsenic flue gas environment, is convenient for industrialized production and application, is suitable for chemical industry, environmental protection, non-ferrous metal smelting industry, belongs to sulfuric acid production equipment technical field.

The invention discloses an extraction process of collagen peptide. The extraction process comprises the following specific steps: (1) preparing raw materials: selecting animal tissue raw materials; (2) acid leaching treatment: soaking the raw materials in a dilute acid solution, and washing after acid leaching; (3) enzymolysis treatment: adding collagenase to carry out enzymolysis reaction; (4) ultrasonic-assisted extraction: synchronously performing ultrasonic treatment in the enzymolysis process; (5) separation and purification: carrying out centrifugation, filtration and membrane separation and purification on the enzymatic hydrolysate; and (6) drying and storing: drying the solution into dry powder for storage. The invention relates to the technical field of bioactive substance extraction, relates to an extraction process of collagen peptide, and aims to overcome the defects of low extraction efficiency, serious environmental pollution, difficulty in consideration of product purity and biological activity and high production cost in the existing collagen peptide extraction process. The invention provides an extraction process which is synergistically optimized in process steps, environment-friendly, capable of stably obtaining high-purity and high-biological-activity collagen peptide and suitable for large-scale production.

The invention relates to the technical field of preparation of battery materials, and discloses a preparation method of battery-grade iron phosphate, which comprises the following steps: taking industrial-grade iron phosphate as a raw material, fully dissolving the industrial-grade iron phosphate with dilute acid, carrying out solid-liquid separation to obtain a feed liquid, enabling the ratio of phosphorus to iron in the feed liquid to be (0.9-1.25): 1, and enabling the pH value of the feed liquid to be 0-1 at the moment; heating the feed liquid to 70-100 DEG C, and aging to fully precipitate the iron phosphate, so as to obtain slurry containing the iron phosphate; extracting iron phosphate from the slurry; the dilute acid is at least one of dilute sulphuric acid and dilute nitric acid. The preparation method is simple in process flow and low in cost, and the prepared anhydrous iron phosphate is high in purity.

An apparatus for concentrating dilute acid using a concentration tower includes a concentration tower, a dilute acid preheater, a concentrated acid intermediate tank, a dilute acid pump, and a heat pump. The concentration tower is equipped with heat exchanger one and heat exchanger two. An acid inlet is located at the upper end of the concentration tower and is connected to heat exchanger one. A spray pipe is connected to the lower section of the concentration tower, and the liquid outlet of heat exchanger one is connected to the spray pipe. An acid outlet is located at the lower end of the concentration tower. The dilute acid preheater has a dilute acid inlet at one end and a dilute acid outlet at the other end. The dilute acid inlet is connected to the dilute acid pump, and the dilute acid outlet is connected to the acid inlet. The heat pump is connected to the heat source inlet of heat exchanger one, and the heat source outlet of heat exchanger one is connected to the heat source inlet of heat exchanger two via a heat transfer pipe. A flash heat source outlet is located at the lower section of the concentration tower and is connected to the dilute acid preheater. This invention is applicable to the concentration of various dilute acids such as dilute phosphoric acid and dilute sulfuric acid, improving both concentration efficiency and process stability.