122results about "Alkali metal nitrate purification" patented technology

The invention relates to a method for recovering dimethyl sulfone and sodium nitrate from dimethyl sulfoxide waste slag, which comprises arranging waste slag waste slag in a decompression autoclave at 120-160DEG C to decompress and distill, distilling out the dimethyl sulfoxide and dimethyl sulfone from dimethyl sulfoxide waste slag to be arranged into an another autoclave to be cooled to obtain crystallized solid, arranging the distilled dimethyl sulfoxide and dimethyl sulfone into enough hydrogen dioxide solution to be oxidized and dried in vacuum to obtain dimethyl sulfone product, dissolving leavings in water to be discharged, adding concentrated nitric acid into the filtered mother liquid to adjust pH till 2-3 and convert sodium nitrite to sodium nitrate, neutralizing over nitric acid via soda, to neutralize the mother liquid, heating the solution to 120-125DEG C, evaporating at normal pressure, cooling to 50-70DEG C, crystallizing, separating and drying to obtain sodium nitrate product. The invention can reduce discharge of industrial waste slag and reduce environment pollution, with simple process and low energy consumption.

The invention relates to a concentrated salt water zero discharging membrane concentration and quality grading crystallization process and concentrated salt water zero discharging membrane concentration and quality grading crystallization equipment. The concentrated salt water zero discharging membrane concentration and quality grading crystallization process comprises a pretreatment step, a membrane concentration treatment step, and a quality grading crystallization treatment step, wherein a pretreatment device comprises a high-grade oxidation unit and a softening microfiltration unit, the membrane concentration treatment step comprises nano-filtration membrane separation, seawater desalination reverse osmosis membrane separation and super-concentration separation, and the quality grading crystallization process comprises separating a sodium chloride and sodium sulfate mixing salt and a sodium nitrate product salt. According to the present invention, by combining a variety of concentration processes, the concentrated salt water treatment efficiency of the equipment can be effectively improved, the purpose of reduction and zero discharging of the concentrated salt water can be achieved, and the running cost of the concentrated salt water treatment equipment can be reduced.

An industrial waste salt resourceful treatment method comprises the following steps: the industrial waste salt is sequentially subject to dissolving, chemical pre-purification, deep purification, organic matter concentration reduction, adsorption and oxidation decolorization and multi-effect evaporative crystallization to respectively obtain sodium sulfate, sodium chloride and sodium nitrate crystals; the crystallization temperature of sodium sulfate is in a range of 75° C. to 85° C.; the crystallization temperature of sodium chloride is in a range of 60 to 70° C.; and the crystallization temperature of sodium nitrate is in a range of 45° C. to 55° C. An industrial waste salt resourceful treatment device is further provided.

The invention offers a kind of method of producing sodium nitrate which belongs to technique field of inorganic chemical industry. This method uses the following raw material and steps to make sodium nitrate: 1. vaporize and dispose bittern solution and sodium nitrate vaporization mother liquor with certain volumetric ratio to get sodium nitrate mixture in the form of plasm; 2.separate solid and liquid, get salt-mixture of sodium sulfate and sodium chloride or sodium sulfate or sodium chloride and vaporization mother liquor to make salt; 3. vaporize and dispose vaporization mother liquor to make salt and get vaporization mother liquor to make salt in the form of plasm; 4. Separate solid and liquid, get vaporization mother liquor which continues to circulate and join in working procedure of salt preparation at high temperature using evaporation in step 1 and finished product of sodium nitrate. Utilizing ratio of raw material in this invention is high, quality of products is also high, with low energy consumption and production cost and it has no discharge of the three wastes.

The invention provides an industrial waste salt resourceful treatment method and equipment. The method comprises the following steps: sequentially dissolving industrial waste salt, chemically pre-removing impurities, deeply removing impurities, concentrating and reducing organic matters, and carrying out adsorption oxidation decolorization and multiple-effect evaporative crystallization to respectively obtain sodium sulfate, sodium chloride and sodium nitrate crystals; wherein the crystallization temperature of the sodium sulfate is 75-85 DEG C; the crystallization temperature of sodium chloride is 60-70 DEG C; and the crystallization temperature of sodium nitrate is 45-55 DEG C. According to the industrial waste salt resourceful treatment method provided by the invention, the organic matters and other impurities in the industrial waste salt are firstly removed by adopting the steps, then salt separation and crystallization are realized by controlling the temperature in the evaporationprocess, and the industrial waste salt is obtained by utilizing the difference of three-phase co-saturation points of the sodium chloride, sodium nitrate and sodium sulfate at different temperaturesand the solubility of each salt. And the purity and whiteness of the sodium chloride, sodium nitrate and sodium sulfate obtained by salt separation crystallization all reach industrial-grade standards, and the sodium chloride, sodium nitrate and sodium sulfate can be directly applied.

The invention relates to a method for removing organic matters from high organic matter carnallite and recycling inorganic salt, and belongs to the field of treatment of waste water and hazardous waste. The method for removing organic matters from high organic matter carnallite and recycling inorganic salt comprises the following steps: step 1, introducing high organic matter carnallite waste water into an evaporator to conduct normal pressure or reduced pressure evaporation until the mass percent of the inorganic salt is 20%-25%, or conducting evaporative crystallization to obtain inorganic salt and a small amount of mother solution; step 2, preparing the concentrated solution or mother solution in the step 1 into a shaped solid; step 3, loading the solid in the step 2 into a dry distillation furnace, and conducting treatment at 300-700DEG C for 30-300min; step 4, adding water to the solid after dry distillation, conducting stirring and liquid solid separation, removing insoluble solid to obtain a saline solution; and step 5, crystallizing the saline solution in the step 4 to obtain the inorganic salt. The method for removing organic matters from high organic matter carnallite and recycling inorganic salt has high removal rate (above 99%) of organic matters, innocent treatment of the technical process, no secondary emission of hazardous waste and low cost.

The invention relates to a preparation method of potassium nitrate. The preparation method comprises steps of dissolving, crystallizing, washing, dehydrating and drying. By utilizing the preparation method, the purity of the potassium nitrate is greatly improved, contents of various impurities in the potassium nitrate are greatly reduced, and the requirements on the high-purity potassium nitrate by various industries are met. By utilizing a one-step purification method for purified water production, the investment is greatly reduced, the energy consumption is reduced, the production cost is reduced, large-scale industrial production can be formed, and mass requirements on the high-purity potassium nitrate in a market are met.

The invention relates to the technical field of chemical industry, in particular to a treatment method for potassium nitrate wastes. The method comprises the following steps: (a) collecting the potassium nitrate wastes generated during chemical enhanced treatment of glass, and adding water for mixing to obtain dilute waste liquor, wherein the concentration of potassium nitrate in the dilute waste liquor is 40-70%; (b) heating the dilute waste liquor to 50-100 DEG C for fully dissolving, performing filtration treatment on dissolved liquor to remove sodium nitrate and other impurities, cooling filter liquor obtained by filtering to lower than a room temperature, crystallizing, dewatering, and drying to obtain potassium nitrate powder. The potassium nitrate wastes are treated with the method for diluting and heating for dissolving, and then the filtration treatment is adopted for removing a relatively large amount of sodium nitrate, impurities and the like in the potassium nitrate wastes, so that the concentration of potassium nitrate in a potassium nitrate solution can be increased, a purification effect is achieved, and the obtained potassium nitrate powder can be sold as a product; specifically, the market price of existing potassium nitrate byproduct wastes is 1,000 yuan/ton, and the price of the potassium nitrate powder obtained after the potassium nitrate wastes are treated with the method disclosed by the invention is 10,000 yuan/ton.

The invention discloses a method for preparing industrial potassium nitrate from a potassium nitrate crude product by virtue of the recrystallization method, and relates to the technical field of inorganic chemical industry. A 2 to 5-stage continuous crystallization manner is adopted, and a crystallization device is formed by connecting a flash evaporator and liquid phases of 2 to 5 crystallizers in series, wherein the temperature of a potassium nitrate crude product solution is 70 to 78 DEG C, and the saturation of the potassium nitrate crude product solution is 90 to 91 percent; the temperature of a flash evaporator solution is 59 to 67 DEG C, the corresponding flash steam temperature is 54 to 61 DEG C, and the flash steam pressure is 112 to 156 mm Hg; the temperature of a liquid phase outlet of the final crystallizer is 17 to 19 DEG C, the corresponding flash steam temperature is 16 to 18 DEG C, and the flash steam pressure is 14 to 15 mm Hg; the flash steam rate is 22 to 27 percent, and the potassium nitrate crystallization rate is 79 to 84 percent. The industrial potassium nitrate state standard GB 1918-2011 is executed to produce high-class and first-class industrial potassium nitrate.

The invention discloses a balanced circulating mother liquor purification method based on an evaporation salt making system. Three stages of evaporation are adopted for mother liquor of the salt making system, a high-purity sodium nitrate intermediate product is produced, sodium sulfate and sodium chloride are separated out by crystallization, the high-temperature mother liquor is conveyed back to the evaporation salt making system for continuous circulating balance, sodium nitrate circulating mother liquor circulates, and sodium nitrate circulating mother liquid components are balanced by adding fresh water and discharging the mother liquor. Three stages of evaporation are adopted for the salt making system, the sodium nitrate circulating mother liquor components are balanced by adding the fresh water and discharging the fresh water, in this way, discharging of three wastes does not exist, product quality is high, the utilization rate of raw materials is high, reaction time is obviously shortened, equipment investment and process operating cost are saved, the total steam consumption is lowered by 20% or above per ton of sodium nitrate, energy is saved, environmental protection is achieved, flashing intensity can be reduced, the production period can be effectively prolonged, the utilization rate of heat energy can be increased, and system productivity can be improved. Meanwhile, the method has the advantages of being high in purification efficiency and low in energy consumption.

The invention relates to a resourceful treatment method of TDI industrial wastewater. The resourceful treatment method sequentially comprises the following steps: (1) removing calcium and magnesium ions and bicarbonate radicals from mixed miscellaneous salt wastewater rich in sodium nitrate, sodium chloride and sodium sulfate through a pretreatment unit; (2) realizing separation of divalent salt and monovalent salt through a salt separation unit; (3) re-concentrating the divalent salt to enable the concentration of the sodium sulfate solution to reach 9.86%, and performing freezing crystallization in a sodium sulfate freezing crystallization unit at 0 DEG C; re-concentrating the monovalent salt mixed solution to enable the concentration of sodium chloride to reach 4% and the concentrationof sodium nitrate to reach 9.9%; (4) the monovalent salt mixed solution enters a sodium chloride evaporative crystallization unit for multiple-effect evaporation so that sodium chloride is crystallized and separated out and is separated from a sodium nitrate solution; and (5) cooling the sodium nitrate solution by flash evaporation of the sodium nitrate flash evaporation unit, and cooling to normal temperature in the sodium nitrate cooling crystallization unit to crystallize sodium nitrate, and carrying out hot melting crystallization on sodium sulfate, and drying to obtain sodium sulfate withthe purity of 99%. Mixed miscellaneous salt is classified and recycled, the productivity is high, and the quality of crystalline salt is good.

The invention discloses a method for quickly converting NOx tail gas into potassium nitrate, and solves the problems of the conventional tail gas treatment for existing enterprises in the prior art, such as high tail gas treatment cost, environmental pollution and the like. The method is characterized in that a nitrogen oxide and a potassium chloride solution (or a mixed solution) are rapidly converted into potassium nitrate in an absorption tower. The purity of potassium nitrate is controlled through controlling the concentration of dilute nitric acid, the volume of dilute nitric acid and the added amount of potassium chloride, and the purity of potassium nitrate is further improved through adopting the saturated solution of potassium nitrate as a scrubbing solution. Meanwhile, the yield of potassium nitrate is judged based on the concentration of Cl. Specifically, the method comprises the steps of (1) absorbing the industrial tail gas containing NOx, and converting the tail gas into nitric acid, wherein a 1% salt crystallization inhibitor is previously added in an absorbent; (2) reacting nitric acid with potassium chloride to convert the tail gas into potassium nitrate; (3) separating the HCl gas and dissolving out the potassium nitrate; (4) washing and separating the potassium nitrate; (5) drying the potassium nitrate and recycling the filtrate. The above method has the advantages of convenient operation, environmental protection, energy saving and the like. Based on the method, the NOx-contained tail gas of a chemical enterprise is directly converted into the potassium nitrate. Therefore, the method has wide popularization and application value.

The invention relates to a molten salt impurity removal method suitable for chemical tempering production and a method for improving glass strength. The molten salt impurity removal method suitable for chemical tempering production comprises the following steps: adjusting the pH value of molten salt to 9-14; adding a precipitant into the molten salt, performing mixing treatment to enable the precipitant to react with impurity ions in the molten salt to generate precipitate, and adjusting the pH value of the molten salt to 6.8-7.2; and adding an adsorbent, and standing to clarify the molten salt. The molten salt impurity removal method for chemical tempering production is simple to operate, and experiments prove that the effect of removing impurities from molten salt by adopting the methodis obviously better than that of a traditional molten salt impurity removal method.

The invention relates to a continuous potassium nitrate production system and a production method combined with production of liquid ammonium nitrate. The system comprises a potassium nitrate production system and a liquid ammonium nitrate production system, wherein the potassium nitrate production system comprises a dissolving tank, a potassium nitrate vacuum crystalizing device, a primary thickener, a primary centrifugal machine, a mixing tank, a concentration preheater, a reflux triple effect concentrating device, a vacuum continuous crystalizing device, a secondary thickener, and a secondary centrifugal machine, wherein the liquid ammonium nitrate production system comprises an ammonia evaporator, a gaseous ammonia filter, an ammonia preheater, a tubular reactor, a neutralizing scrubbing tower and a flash tank. The invention develops the new continuous potassium nitrate production system combined with production of liquid ammonium nitrate, so that the efficiency of potassium nitrate production technology is improved, the crystalizing process is controlled more accurately, and the potassium nitrate crystalline quality and yield are more stable.

The present invention relates to a method for separating and recovering a purified alkali metal salt from an aqueous alkali metal salt solution, the method including a treatment step of removing a purification-inhibiting substance from an aqueous alkali metal salt solution with a separation membrane having a glucose removal ratio and an isopropyl alcohol removal ratio simultaneously satisfying the following expressions (I) and (II) when each of a 1000 ppm aqueous glucose solution having a temperature of 25° C. and pH of 6.5 and a 1000 ppm aqueous isopropyl alcohol solution having a temperature of 25° C. and pH of 6.5 is permeated through the separation membrane at an operating pressure of 0.75 MPa: Glucose removal ratio>=90% . . . (I), Glucose removal ratio-Isopropyl alcohol removal ratio>=30% . . . (II).

The invention relates to a preparation method of guaranteed-reagent potassium nitrate, which includes the following steps: 1) purification and iron impurity removal of industrial potassium nitrate: placing the industrial potassium nitrate in a glass beaker, dissolving the industrial potassium nitrate in distilled water, heating the solution on an electric stove at 85 DEG C to dissolve the industrial potassium nitrate, adding potassium carbonate and heating the solution to 110 DEG C to generate precipitate with continuous stirring, allowing the solution to stand for 2 h and filtering the solution to obtain a solution A; 2) re-crystallization to prepare the guaranteed-reagent potassium nitrate: concentrating the solution A obtained in the step 1) at 170 DEG C to separate crystal out, cooling and spin-drying the crystal, performing re-crystallization, spin-drying the crystal, and drying the crystal in an electric dry oven at 75 DEG C for 5 h to obtain the guaranteed-reagent potassium nitrate. In the method, the guaranteed-reagent potassium nitrate is dissolved in hot water to form a solution which is then boiled with addition of the potassium carbonate to remove the iron impurity. The solution is then cooled and filtered, and finally is dried and crystallized to obtain the guaranteed-reagent potassium nitrate.

The invention relates to a method for recovering sodium nitrate from silver waste water, belonging to the technical field of environmental protection. The method for recovering the sodium nitrate from the silver waste water is characterized by comprising the following steps of: carrying out alkaline oxidation cyanide breaking on the silver waste water; adding acids for neutralization, and then filtering a solution for evaporation and concentration; and cooling and crystallizing to obtain the sodium nitrate. The method for recovering the sodium nitrate from the silver waste water has the advantages of simple operation method, economy and environmental protection and can sufficiently utilize the resources, thereby enhancing the economic benefits to a certain degree.

The invention discloses a system and method for producing potassium nitrate by adopting a continuous double-decomposition method. The system comprises a primary dissolving tank, a potassium nitrate vacuum crystallization device, a primary thickener, a primary centrifugal machine, a washing tank, a secondary dissolving tank, a filtering machine, a primary vacuum continuous crystallizer, a secondary thickener, a secondary centrifugal machine, a mixing tank, a concentrating preheater, a countercurrent triple-effect concentrating device, a secondary vacuum continuous crystallizer, a triple thickener and a triple centrifugal machine. According to the system and method for producing potassium nitrate by adopting the continuous double-decomposition method, disclosed by the invention, the production capacity is enlarged, the labor production intensity is reduced, and the production efficiency of a production process of the potassium nitrate is improved.

Relating to the field of purification of toughened glass waste liquid, the invention discloses a method for purification of potassium nitrate in toughened glass waste liquid. The method includes the steps of: (1) cooling toughened glass waste liquid containing potassium nitrate, then adding water for dissolving, and conducting filtering to obtain a solid impurity removed solution; (2) carrying out adding of potassium carbonate and potassium sulfate and solid-liquid separation repeatedly on the solution to obtain a clarified solution; (3) conducting ion exchange and filtration for impurity removal on the clarified solution repeatedly to obtain an impurity removed solution; (4) adding an HCl solution into the impurity removed solution, and performing centrifugal separation to obtain a potassium nitrate-containing solution; and (5) carrying out aftertreatment on the potassium nitrate-containing solution to obtain purified potassium nitrate powder. The method provided by the invention can effectively remove solid impurities, Ca<2+>, Mg<2+>, Ba<2+>, Sr<2+> and the like from the toughened waste liquid, also can fully convert NaNO3 in the solution into KNO3 and enable reuse of the toughened waste liquid, and has the advantages of cost saving and environmental friendliness.

The invention provides a method for recovering reagent grade sodium nitrate from waste liquid generated in a production process of citric acid bismuth prepared by the reaction of nitric acid bismuth solution with citric acid and sodium carbonate solution. The method comprises the following steps: heating and concentrating the collected waste liquid until the proportion of the heat solution is 1.15-1.20; adding 5-8% of ammonium nitrate into the waste liquid, wherein the molar ratio of the ammonium nitrate is equal to that of the sodium nitrite in the waste liquid; heating to microboil to remove the impurities of nitrite; adding calcium hydroxide to remove a small amount of residual citric acid in the reaction; adding the sodium carbonate to regulate the pH value of the waste liquid; preserving the temperature to remove the heavy metal impurities and excessive calcium; regulating the pH value of the filtrate by nitric acid; and concentrating and crystallizing to obtain the reagent grade sodium nitrate. The method for recovering the sodium nitrate is simple in operation and moderate in process condition, can be used for effectively removing various purities in the waste liquid; the comprehensive recovery rate is up to 75-85%; and the obtained product conforms to the analytically pure standard of GB/T 636-1992 chemical reagent. In the invention, the waste liquid is comprehensively processed and utilized to recover the reagent grade sodium nitrate, thus achieving the purposes of saving the energy, reducing the emission, lowering the environment pollution and lowering the production cost.

The invention discloses a production process of temperature-controlled cyclic layer-by-layer sodium nitrate separation. The production process comprises the following steps: soaking nitronatrite ore with water to form a three-salt system liquid of sodium chloride NaCl, sodium nitrate NaNO3 and sodium sulfate Na2SO4; producing sodium chloride by low-temperature salt slurry whirl in the heating treatment process; extracting sodium sulfate from high-temperature salt slurry by virtue of a liquid-liquid separator; and returning a mother liquid to an evaporation system to use in cycle, and gradually separating and washing a salt slurry separator, so that heat energy is reduced; the water consumption is reduced; industrial pollution is reduced; the production process is mainly applied to comprehensive utilization of nitronatrite ore resources; production of the sodium nitrate is achieved; by-production of the sodium chloride and the sodium sulfate is achieved; waste salt is divided into two products, namely the sodium sulfate and the sodium chloride, so that the production value is increased; and the comprehensive economic benefits are improved.

The invention discloses a fully-automatic production line type potassium nitrate recovering process. The wastes are potassium nitrate wasted after glass strengthening, the wastes are crushed, added into water, heated to dissolve, and cooled and crystallized after being dissolved, crystals are washed by water and centrifugally separated, and the centrifugally separated solids are subjected to drying and dehumidifying, so as to obtain a finished product potassium nitrate. The fully-automatic production line type potassium nitrate recovering process provided by the invention has high yield, high recovering rate and high quality of a recovered product.

The invention provides a nitrogen oxide absorption device. The device comprises a washing unit and a reaction unit, wherein the washing unit comprises a plurality of absorption towers which are connected in series; each absorption tower is an absorption tower adopting alkali liquid circulation; the reaction unit comprises a reaction kettle A and a reaction kettle B; a filler absorption tower is arranged at the top of the reaction kettle B; the top of the filler absorption tower is connected with a liquid outlet of an injection pump; a vacuum chamber of the injection pump is connected to the top of the reaction kettle A; two nitric acid high-level storage tanks and a waste gas discharging opening connected with an induced draft fan are further arranged at the top of the reaction kettle A; acirculating pump is connected between the bottom of the reaction kettle B and a liquid inlet of the injection pump. The invention further provides a method for realizing separation of absorption products including sodium nitrate and sodium nitrite by utilizing the absorption device. According to the method provided by the invention, nitrogen oxide is firstly introduced into the absorption towersand is absorbed by alkali liquid to be converted into mixed salt; then nitric acid with different concentrations is added into the mixed salt, the pH (Potential of Hydrogen) value of a reaction solution is controlled and then the sodium nitrate and the sodium nitrite are obtained. The method provided by the invention can really realize clean recycling of the nitrogen oxide.