26results about "Thiocyanic acid" patented technology

The invention belongs to the technical field of solid pollutant treatment, and particularly relates to a method for removing cyanide in cyanidation tailings through metal activated persulfate oxidation. The problems that different cyanide removal mechanisms are different, the removal efficiency is low, the cost is high, secondary pollution is easily caused and the like exist in treatment of the cyanidation tailings. The tailings are subjected to cyanogen reduction treatment by adopting a stage treatment method. The method comprises the following steps: firstly, crushing the tailings to prepare a charcoal-loaded metal composite material Me / BC; when free cyanide in the tailings is smaller than or equal to 50 mg / kg, Me / BC activated persulfate is used for conducting cyanide reduction treatment on the tailings; when the tailings contain free cyanide gt; when the concentration is 50 mg / kg, free cyanides in the tailings are removed through leaching, and then Me / BC is used for activating persulfate to degrade strong complex state cyanides in the tailings. By adopting the method, the problems that complex cyanide is difficult to remove by a single leaching method and persulfate is large in dosage and high in cost in a single oxidation method can be solved, and the cascade cyanogen removal method is efficient, low in cost and free of secondary pollution.

The invention relates to a method for separating sodium sulfate and sodium thiocyanate from a mixed waste salt solution, which comprises the following steps: carrying out catalytic oxidation, decoloration treatment and first solid-liquid separation on the mixed waste salt solution, and carrying out first evaporation concentration, first cooling crystallization and second solid-liquid separation on the obtained pretreated solution to obtain a sodium sulfate crude product and a filtrate, washing the sodium sulfate crude product, and carrying out third solid-liquid separation to obtain sodium sulfate; carrying out second evaporation concentration on the filtrate, adding sodium thiocyanate seed crystal, carrying out second cooling crystallization and fourth solid-liquid separation to obtain a sodium thiocyanate crude product and residual liquid, washing the sodium thiocyanate crude product, and carrying out fifth solid-liquid separation to obtain sodium thiocyanate; and circulating the washing waste liquid and the residual liquid to the pretreatment solution for mixing and recycling. According to the method, evaporation concentration is combined with cooling crystallization, sodium sulfate and sodium thiocyanate which are high in purity and extraction rate can be obtained through separation, and the whole preparation process is low in energy consumption and more environmentally friendly and integrally has good economic benefits.

The application provides a preparation method of a biomimetic flagelliform nanowire and relates to the technical field of nanowire material preparation. The method comprises the following steps: mixing and immersing a trithiocyanic acid solution and copper hydroxide nanowires, and obtaining immersed nanowires after drying; the immersion conditions comprise the following steps: the temperature is 20-45 DEG C, and the time is 0.01-50 min; and the obtained immersed nanowires are calcined at 250-500 DEG C for 2-6 h. The method provided by the application uses a trithiocyanic acid solution to immerse Cu(OH)2 nanowires, and then calcines in a muffle furnace. The method provided by the application is simple in operation, the prepared nanowires are uniform and controllable in morphology, and can be applied to the fields of oil-water separation, battery negative electrode current collectors, adsorption and the like.

The application provides a method for preparing calcium thiocyanate by using desulfurization waste liquid, calcium nitrate and ammonium thiocyanate are respectively dissolved into 30-50% solution, the calcium nitrate solution is slowly dropped into the hot ammonium thiocyanate solution under the conditions of heating and stirring, under the heating state, the double decomposition reaction occurs to generate calcium thiocyanate and ammonium nitrate, with the continuous heating and the evaporation of water, the concentration of calcium thiocyanate gradually increases, the ammonium nitrate is heated and decomposed to generate nitrogen oxide and ammonia gas, the generated process gas rich in nitrogen oxide and ammonia gas is condensed and introduced into the coking ammonia removal and denitration section for treatment, and finally the evaporation and concentration obtain about 50% calcium thiocyanate product. The method uses industrial waste to provide raw materials, and the production cost is low; the process tail gas generated in the reaction only needs to be treated by the existing ammonia removal and denitration device of the coking enterprise, without increasing additional equipment, thereby saving the expenditure; and the method has environmental protection benefit, social benefit and economic benefit.

The utility model relates to a device for optimizing co-production of acid and ammonium thiocyanate from desulfurization waste liquid. The device comprises a tank body and a cover body, a jacket is arranged on the outer wall of the tank body, a cooling cavity is formed between the jacket and the outer wall of the tank body, a medium inlet and a medium outlet are formed in the jacket, and the medium inlet and the medium outlet are both communicated with the cooling cavity; a filter plate is arranged in the tank body; an ammonium thiocyanate mother liquor outlet and a sulfo-impurity discharge hole are formed in the lower part of the side wall of the tank body; and the cover body is provided with a sulfur-containing concentrated solution inlet and a backwashing solution inlet. The device is not provided with an incineration structure and procedure, the problem that high-added-value ammonium thiocyanate is incinerated in the existing process of preparing acid from desulfurization foam and desulfurization waste liquid is solved, the problem that nitric oxide is too high in the acid preparation incineration process is solved, and therefore the problem that the content of nitrate in finished acid is too high is solved; according to the device, the process of preparing ammonium thiocyanate from the sulfur-containing concentrated solution and the process of preparing the sulfur-containing waste solution for acid making are integrated through the device, so that the process energy consumption is reduced, and the resources and the cost are saved.

The present invention relates to a method for separating sodium sulfate and sodium thiocyanate from a mixed waste salt solution. The method comprises subjecting the mixed waste salt solution to catalytic oxidation, decolorization, and a first solid-liquid separation, then subjecting the obtained pretreatment solution to a first evaporation concentration, a first cooling crystallization, and a second solid-liquid separation to obtain a crude sodium sulfate product and a filtrate, washing the crude sodium sulfate product, and subjecting the pretreatment solution to a third solid-liquid separation to obtain sodium sulfate; subjecting the filtrate to a second evaporation concentration, adding sodium thiocyanate seed crystals, and then subjecting the pretreatment solution to a second cooling crystallization and a fourth solid-liquid separation to obtain a crude sodium thiocyanate product and a residual liquid, washing the crude sodium thiocyanate product, and subjecting the pretreatment solution to a fifth solid-liquid separation to obtain sodium thiocyanate; and recycling the washing waste liquid and the residual liquid to the pretreatment solution for mixing and reuse. The present invention utilizes evaporation concentration combined with cooling crystallization to separate sodium sulfate and sodium thiocyanate with high purity and extraction rate. The entire preparation process has low energy consumption, is more environmentally friendly, and has good overall economic benefits.

The invention belongs to the technical field of waste treatment in the coking industry and relates to a deep processing process for sulfur paste, a by-product of coke oven gas desulfurization. The process comprises the following steps: decolorization of the sulfur paste, first centrifugal filtration, acidification and impurity removal, preparation of sodium thiosulfate, second centrifugal filtration, concentration and precipitation of ammonium sulfate and ammonium thiocyanate, centrifugal separation, concentration of sodium thiosulfate, crystallization of sodium thiosulfate, first separation of sodium thiosulfate pentahydrate, purification of sodium thiosulfate pentahydrate and second separation of sodium thiosulfate pentahydrate. Through efficient conversion, separation and impurity removal, the solid waste sulfur paste can be processed into high-value-added sodium thiosulfate pentahydrate crystals, thereby truly realizing high-quality resource utilization of pollutants.

The invention discloses a preparation method and multifunctional application of a self-powered three-mode sensor based on double photoelectrodes, and belongs to the field of food-borne pathogenic bacterium detection. CuI / CuSCN is used as a photoelectric cathode material, NTW is used as a photoelectric anode material, the Fermi level difference between the two electrodes is utilized, bias voltage and an oxidation-reduction medium do not need to be additionally arranged, and the photoelectric sensor has the advantages of high light energy utilization rate, portability and anti-interference capability. Au NPs is further modified on the surface of the photoanode material, and an aptamer is connected through an Au-S bond to serve as a recognition element, so that a novel dual-photoelectrode self-energized aptamer sensor is constructed. Besides, photoelectrochemistry, electrochemistry and fluorescence three-mode sensing and photocatalytic sterilization technologies are introduced into the self-powered system, so that the detection accuracy and sensitivity are improved, and a feasible scheme is provided for detecting and killing food-borne pathogenic bacteria at the same time.

The invention relates to the technical field of salt extraction and recovery of sodium-process desulfurization waste liquid, in particular to a method and device for extracting product-grade sodium thiocyanate from sodium-process desulfurization waste liquid, and the method comprises the following steps: step a, primary decoloring treatment, step b, primary concentration crystallization, step c, secondary decoloring treatment, step d, freezing crystallization, step e, precise desalting, and step f, secondary concentration crystallization. A stepped process design of two-time decoloration, fractional crystallization and precise desalination is adopted, aiming at the physicochemical property difference of three core salts of sodium sulfate, sodium thiosulfate and sodium thiocyanate in the sodium-process desulfurization waste liquid, efficient separation is realized by accurately controlling process parameters, the sodium sulfate is preferentially separated out by utilizing the characteristic that the solubility of the sodium sulfate is relatively low at high temperature, and the sodium thiosulfate is separated out by utilizing a high-temperature crystallization method. The sodium thiocyanate is separated out in a targeted manner on the premise of ensuring that the sodium thiocyanate is in an unsaturated state, so that the technical problem that the sodium thiocyanate is easy to co-crystallize at low temperature is solved.

The invention discloses a synthesis method of a C-13 labeled mercapto triazole derivative. The synthesis method comprises the following steps: (1) carrying out a reaction on C-13 potassium cyanide and S8 to prepare C-13 potassium thiocyanate; (2) carrying out nucleophilic substitution reaction on C-13 potassium thiocyanate and a benzyl bromide compound to obtain a compound 1; (3) carrying out nucleophilic addition reaction on the compound 1 and formylhydrazine to obtain a compound 2; (4) further cyclizing the compound 2 under an alkaline condition to obtain a compound 3; and (5) carrying out derivative reaction on the compound 3 to obtain a C-13 labeled target compound. According to the synthesis method, multi-step continuous reaction is adopted, operation is easy and convenient, the yield is high, and the utilization rate of the C-13 marker is greatly increased.

The utility model belongs to the field of industrial waste liquid treatment and recovery, disclose is a kind of coking desulfurization waste liquid salt extraction system, including pretreatment system and first salt extraction system;The pretreatment system includes first reaction kettle and first filter device, the first reaction kettle with the first filter device is connected, for the impurity removal and filtration of coking desulfurization waste liquid;The first salt extraction system includes crystallization reactor and second filter device, the crystallization reactor includes feed inlet, liquid discharge port and solid discharge port, the feed inlet is used to put in the coking desulfurization waste liquid after impurity removal and copper sulfate solution, the solid discharge port with the second filter device is connected, and the second filter device is used to filter out cuprous thiocyanate. Cuprous thiocyanate reaction precipitation can be realized to filtration treatment, and the processing efficiency is improved.

The invention discloses a method for preparing cuprous thiocyanate by using copper fire refining slag, and relates to the technical field of copper fire refining. According to the method, the copper pyrogenic process refining slag meeting the specific content composition is subjected to chlorination leaching, the refining slag is leached through hydrochloric acid system chlorine salt to obtain the leachate containing the cuprous, then thiocyanate is added for a reaction, and the product cuprous thiocyanate can be obtained. The synthetic route provided by the invention is low in cost and high in product rate, the leaching slag can be returned to prepare nickel matte, and high-value utilization of the copper refining slag is realized.

The application provides a desulfurization waste liquid treatment method, and belongs to the technical field of waste water treatment. The desulfurization waste liquid is subjected to step-by-step salt extraction to obtain ammonium thiosulfate, ammonium thiocyanate and ammonium sulfate; the ammonium thiosulfate is purified by using ethanol to obtain pure ammonium thiosulfate; the ammonium thiocyanate is purified by using ethyl acetate-acetone and ethyl acetate step by step to obtain pure ammonium thiocyanate; and the ammonium sulfate is purified by using a water-acetone mixed solution to obtain pure ammonium sulfate. The application first subjects ammonium thiosulfate, ammonium thiocyanate and ammonium sulfate in the desulfurization waste liquid to rough extraction by using step-by-step salt extraction, and then subjects the ammonium thiosulfate, ammonium thiocyanate and ammonium sulfate to purification by using specific solvents, so that pure ammonium thiosulfate, pure ammonium thiocyanate and pure ammonium sulfate with high purity are obtained, and the added value of the products is effectively improved.

The present application relates to the technical field of chemical wastewater recycling treatment, and discloses a method and device for extracting ammonium thiocyanate. The method comprises the following steps: performing primary solid-liquid separation on a mixed solution of pretreated high-purity vanadium wastewater and coal gas desulfurization waste salt to precipitate anhydrous sodium sulfate; performing secondary solid-liquid separation on the solution after the primary solid-liquid separation to precipitate a mixed salt of sodium sulfate and ammonium sulfate; and performing tertiary solid-liquid separation on the solution after the secondary solid-liquid separation to obtain ammonium thiocyanate. The method can solve the problems of efficient treatment of high-purity vanadium wastewater and difficulty in treatment or resource utilization of coke oven gas desulfurization waste residue, so as to achieve waste treatment with waste and resource recycling, and greatly reduce the treatment investment cost and operation cost of the two pollutants.

The utility model relates to the technical field of chemical treatment, in particular to a continuous automatic treatment system for converting ammonium salt into sodium salt, and provides a continuous automatic treatment system for converting ammonium salt into sodium salt. Comprising a liquid caustic soda storage tank, an ammonium liquid storage tank, a feed liquid mixer, a sodium conversion rising film evaporation ammonia discharger, a gas-liquid separator, a condensation heat exchanger, an ammonia still device, an ammonia absorption tower device and a sodium liquid storage tank, the liquid caustic soda storage tank is communicated with the feed liquid mixer through a liquid caustic soda conveying pipe, and the ammonium liquid storage tank is communicated with the feed liquid mixer through a liquid ammonium salt conveying pipe. The feed liquid mixer is communicated with the condensing heat exchanger through an alkali-ammonium mixed liquid conveying pipe; the sodium conversion rising film evaporation ammonia discharger is communicated with the gas-liquid separator through a separation pipe; the device has the technical effects that the ammonium-to-sodium treatment effect is good, the automation efficiency is high, few ammonia water impurities are obtained, few ammonium radicals are remained in a sodium solution, and energy conservation and high efficiency are facilitated.

The invention provides a method for resource utilization of desulfurization waste liquid and sulfur foam and application, and relates to the technical field of chemical waste liquid treatment. Specifically, the method comprises the following steps: carrying out two-stage separation treatment on the desulfurization waste liquid and sulfur foam to obtain solid or molten elemental sulfur and separated clear liquid; separating the separated clear liquid into a first clear liquid and a second clear liquid; adding copper salt into the first clear liquid, and then carrying out solid-liquid separation to obtain cuprous thiocyanate and a first mother solution; sequentially carrying out concentration, cooling crystallization and solid-liquid separation on the second clear liquid to obtain ammonium thiocyanate and a second mother solution; concentrating the first mother solution and the second mother solution to obtain a concentrated salt solution; and the concentrated salt liquid and elemental sulfur are mixed and cured, and crude sulfur is obtained. The process method is simple and controllable, elemental sulfur and ammonium salt in the desulfurization waste liquid and sulfur foam are treated at the same time, the recycled crude sulfur can be subjected to resource utilization to prepare concentrated sulfuric acid, high-value by-products can be obtained at the same time, and good economic benefits and application prospects are achieved.

The invention relates to a sulfur foam liquid salt extraction and acid making coupling process, which comprises the following steps: carrying out solid-liquid separation on sulfur foam liquid to obtain a first solid material and a first liquid material, decoloring the first liquid material, and concentrating to obtain a slurry material and a second liquid material; the first solid material and the slurry material are incinerated, and first synthesis gas is obtained and used for preparing concentrated sulfuric acid; and cooling the second liquid material, and centrifuging to obtain ammonium thiocyanate. The sulfur foam liquid is subjected to solid-liquid separation, so that the waste liquid amount is reduced, the equipment volume in the salt extraction area is reduced, and the cost is reduced. An oxidation process in the salt extraction area is canceled, ammonium thiosulfate is subjected to high-temperature concentration and then is subjected to centrifugal separation to obtain crystals, the crystals and the separated ammonium sulfate are sent to the acid making area to be incinerated, and generated tail gas is sent to a desulfurization and denitrification section of a coking plant to be treated, so that emission without solid waste is realized, and maximum utilization of sulfur element and ammonium thiocyanate in sulfur foam liquid is realized.

The invention belongs to the technical field of sodium thiocyanate extraction, and particularly relates to a process for extracting sodium thiocyanate from coking desulfurization and decyanation waste liquid, which comprises the following steps: S1, carrying out catalytic oxidation on desulfurization waste liquid, adding dilute sulphuric acid, and adding a proper amount of liquid caustic soda to adjust the pH value to weak acidity to obtain a material; s2, centrifugally separating out sulfur solids from the materials, enabling the sulfur solids to fall into a sulfur pulping kettle, pumping the sulfur solids into a coking sulfur foam head tank through a pump, enabling the sulfur solids to enter a sulfur melting kettle to obtain sulfur, and obtaining activated carbon from residual slurry; s3, preparing a product sodium sulfate and / or a product sodium thiocyanate; wherein water in the slurry treated in the step S2 is evaporated until the content of sodium thiocyanate is 48-55%, solid sodium sulfate is obtained through centrifugation, and the product sodium sulfate is obtained through drying; and / or decolorizing the centrifuged liquid with activated carbon, filtering to separate out the activated carbon, evaporating water from the liquid until the content of sodium thiocyanate is 72-80%, crystallizing to separate out sodium thiocyanate, and centrifugally separating and drying to obtain the product sodium thiocyanate.

The invention discloses a preparation method of cuprous oxide, cuprous salt and a preparation method thereof, the preparation method of cuprous oxide comprises the following steps: alkali is added into an arsenic-containing copper solution for reaction, cuprous oxide is obtained after solid-liquid separation, the arsenic-containing copper solution meets the condition that 2cAs < 3 + > is greater than cCu < 2 + >, cAs < 3 + > is the molar concentration of trivalent arsenic in the arsenic-containing copper solution, and the cuprous salt is the molar concentration of trivalent arsenic in the arsenic-containing copper solution. CCu < 2 + > is the molar concentration of bivalent copper in the arsenic-containing copper solution. An alkaline reagent is added into an arsenic-containing copper solution with specific arsenic and copper contents to react to prepare a cuprous oxide raw material, and the cuprous oxide raw material is further converted into cuprous salt, so that not only can effective separation of arsenic and copper be realized, but also a high-purity cuprous salt product can be obtained. The method is simple in technological process and easy and convenient to operate and has good implementability and industrial application prospects, and the obtained cuprous salt product is excellent in quality and has high application value.

The invention discloses a cuprous thiocyanate cross-linked porous nanosheet material as well as a preparation method and application thereof, and belongs to the technical field of inorganic catalyst materials. The preparation method provided by the invention comprises the following steps: (1) mixing an aqueous solution A containing copper salt and an aqueous solution B containing thiocyanate, standing, and removing supernatant to obtain a precipitate; and (2) sequentially carrying out centrifugal washing and drying on the precipitate to obtain the cuprous thiocyanate cross-linked porous nanosheet material, the mixing in the step (1) is carried out under an ultrasonic condition; the ultrasonic frequency is 20 to 60 KHz; the ultrasonic treatment time is 20 to 50 minutes. The cross-linked porous nanosheet structure prepared by the invention is beneficial to reaction medium transfer and effective increase of catalytic reaction active area, excellent electrochemical catalytic activity is obtained, and the method is simple in production process, environment-friendly, high in product yield and easy for large-scale production.

This invention discloses a method for desulfurization and decyanation of coke oven gas using synergistic unary and binary catalytic desulfurization. The method includes the following steps: dividing the coke oven gas desulfurization system into one unary catalytic desulfurization unit and multiple binary catalytic desulfurization units, with each unit performing catalytic desulfurization in parallel and synergistically; the unary catalytic desulfurization unit processes 25-30% of the total gas volume, and the combined binary catalytic desulfurization units process 70-75% of the total gas volume. The unary catalytic desulfurization unit uses a phthalocyanine cobalt sulfonate compound desulfurizing agent as a single catalytic system; each binary catalytic desulfurization unit uses a complexed iron catalyst; the unary catalytic filtrate containing PDS catalyst produced by the unary catalytic desulfurization unit is sent to each binary catalytic desulfurization unit for secondary utilization; the coke oven gas after unary and binary synergistic catalytic desulfurization contains H2S < 50 mg / Nm³. 3 The desulfurization process of this invention requires a low alkalinity, which can effectively reduce alkali source consumption and side reactions, resulting in stable desulfurization performance, low waste liquid volume, and no clogging of the desulfurization tower packing.

The present application relates to wastewater treatment material technical field, specifically to a kind of nanometer cuprous thiocyanate, preparation method and application;The preparation method includes the following steps: S1, copper sulfate is stirred and dissolved in water and stirred uniformly, and blue transparent solution is obtained;S2, slowly drop sodium thiosulfate solution into blue transparent solution, and green transparent solution is obtained;S3, slowly drop sodium thiocyanate solution into green transparent solution and react to obtain white precipitate;S4, filter and collect white precipitate and repeatedly clean with anhydrous ethanol and distilled water to remove sodium thiocyanate impurities on the surface of white precipitate, then dry, grind to obtain nanometer cuprous thiocyanate.The application of nanometer cuprous thiocyanate prepared by the present application to adsorb tetracycline antibiotics in wastewater has the advantages of strong stability compared with copper sulfide, not easy to be oxidized by air, and can be recycled multiple times, so that resources are maximized.

The utility model discloses a desulfurization waste liquid concentration device which comprises a concentration kettle, the concentration kettle is connected with a condenser, the condenser is connected with a condensate collecting tank, the condenser is connected with a vacuumizing pipe, a vacuumizing control valve is arranged on the vacuumizing pipe, a primary steam control valve is arranged at a primary steam inlet, and a secondary steam control valve is arranged at a secondary steam outlet. A temperature sensor is arranged in the concentration kettle, the concentration kettle is also provided with a pressure sensor, a pressure release valve is arranged at the top of the concentration kettle, and the vacuumizing control valve, the primary steam control valve, the pressure release valve, the pressure sensor and the temperature sensor are simultaneously connected with a controller. According to the utility model, the ammonia process wet oxidation desulfurization process taking HPF as a catalyst is implemented, the concentration kettle is improved, and the vacuumizing control valve, the primary steam control valve and the pressure release valve are controlled through the controller, so that the phenomenon of material leakage during concentration can be effectively avoided, and the working efficiency is improved.

The utility model discloses a resource utilization system for coking coal coking desulfurization waste liquid. Comprising a reaction tank, a sedimentation tank, a clean water tank, an ultrafiltration device, a first nanofiltration membrane device, a first concentrated solution tank, a second nanofiltration membrane device, a second concentrated solution tank, a third nanofiltration membrane device, a first water producing tank, a first reverse osmosis membrane device, a second water producing tank, a second reverse osmosis membrane device and a concentrate water tank which are sequentially connected on a desulfurization waste liquid water tank through pipelines, the third reverse osmosis membrane device is connected with the evaporative crystallization reactor, the first nanofiltration membrane device is connected with the second water producing tank, and the second nanofiltration membrane device is connected with the first water producing tank. According to the device, the desulfurization waste liquid is subjected to cooperative treatment through all the devices, a high-quality ammonium thiocyanate product with high recovery rate and high purity can be obtained, meanwhile, the device has the advantages of being convenient to operate, easy to control, low in energy consumption, stable in operation, free of seasonal influence, environmentally friendly and the like, the use value is high, and the application prospect is good.

This invention provides a method for separating and purifying coking desulfurization wastewater, comprising the following steps: oxidizing the coking desulfurization wastewater to obtain an oxidized liquid, the oxidized liquid comprising ammonium thiocyanate and ammonium sulfate; concentrating the oxidized liquid by a first evaporation at a first temperature, followed by solid-liquid separation to obtain a first separated liquid; concentrating the first separated liquid by a second evaporation at a second temperature, followed by solid-liquid separation to obtain a second separated liquid and a mixed salt, the mixed salt comprising ammonium sulfate and ammonium thiocyanate; diluting the concentration of ammonium thiocyanate in the second separated liquid to 50-70%, and crystallizing and separating the solid and liquid at a third temperature to obtain a mother liquor and ammonium thiocyanate; the third temperature being 10-40℃; wherein 5℃ ≤ the first temperature difference T1 between the first and second temperatures ≤ 20℃, and 40℃ ≤ the second temperature difference T2 between the second and third temperatures ≤ 70℃. This invention can significantly improve the purity of ammonium thiocyanate and ammonium sulfate products, and the method is highly feasible.

The invention relates to the technical field of salt extraction and recovery of waste liquid from ammonia desulfurization and decyanation, and in particular to a method for extracting and recovering salt from waste liquid from ammonia desulfurization and decyanation and a salt extraction device. The method comprises the following steps: oxidation neutralization, sulfur extraction, primary decolorization treatment, primary concentration and crystallization, secondary decolorization treatment, secondary concentration and crystallization, and by providing a group of activated carbon decolorization treatment before extracting ammonium sulfate and ammonium thiocyanate each time, the adsorption performance of the activated carbon is utilized to adsorb and separate impurities, pigments and heavy metal ions in the waste liquid, so that the extraction purity of both ammonium sulfate and ammonium thiocyanate reaches an optimal level, thereby improving the economic value of salt extraction.