36results about "Alkali metal sulfites/sulfates preparation form" patented technology

The invention provides a desulfurization wastewater quality-divided crystallization processing method and a processing device. Desulfurization wastewater contains sodium chloride and sodium sulfate. The method comprises following steps: adjusting the pH of desulfurization wastewater to 9-12 for the first time, adding an organic sulfur agent and iron ore particles into adjusted desulfurization wastewater, carrying out magnetic separation to obtain precipitates and supernate; adjusting the pH of the supernate to 6.5-7.5 for a second time, carrying out ultrafiltration to obtain concentrated water; subjecting the concentrated water to a reverse osmosis treatment to obtain a reverse osmosis concentrated solution; subjecting the reverse osmosis concentrated solution to a nano filtration treatment to obtain nano filtration producing water and nano filtration concentrated water; subjecting the nano filtration producing water to a concentration treatment and a crystallization treatment in sequence to obtain sodium chloride crystals; and subjecting the nano filtration concentrated water to a concentration treatment and a crystallization treatment in sequence to obtain sodium sulfate decahydrate crystals. Solved are the problems that in conventional desulfurization wastewater quality-divided crystallization processing, the effect is influenced by heavy metal ions, and the salt crystallization amount is large.

The invention relates to a method for preparing platy-monocrystal alpha-aluminum oxide with Na3FSO4 as seed crystals and belongs to the field of preparation of inorganic nonmetal power materials. The method comprises the following steps that firstly, fused salt and Na3FSO4 crystals are added into raw materials containing aluminum and mixed evenly, and a mixed material is obtained; secondly, the mixed material is roasted at 650-1000 DEG C, the roasted mixed material is cooled to the room temperature and then dissolved with hot water at 50-100 DEG C, washing, filtering and drying are carried out, and platy-monocrystal alpha-aluminum oxide is obtained. According to the method, Na3FSO4 seed crystals for preparation are of an obvious hexagonal platy structure, and greatly assist in forming platy aluminum oxide; the roasting temperature is low, and reduction of energy consumption is promoted.

The invention relates to a sodium-sulfate-containing wastewater crystallizing system. A wastewater heater is communicated with an inlet of a circulating pump, an outlet of the circulating pump is communicated with a feeding port of an evaporation crystallizing tank, a discharging port of the evaporation crystallizing tank is communicated with a solid-liquid separator, a discharging pump is arranged between the solid-liquid separator and the evaporation crystallizing tank, and the solid-liquid separator is further communicated with a liquid inlet of the evaporation crystallizing tank; a centrifugal separator is connected with the solid-liquid separator, a mother liquid tank and a finished product collection tank, the mother liquid tank is connected with the inlet of the circulating pump through a backflow pump, a steam inlet and a steam outlet are arranged on the evaporation crystallizing tank, an inlet of a steam-liquid separator is communicated with the steam outlet while an outlet of the same is communicated with the steam inlet through a centrifugal compressor, and an outlet of the steam-liquid separator is further communicated with a liquid inlet of the evaporation crystallizing tank. The sodium-sulfate-containing wastewater crystallizing system is compact in structure, small in occupied area, low energy consumption, long service life and good evaporation crystallizing effect.

The invention belongs to technical field of chemical brine wastewater treatment, and particularly relates to a brine wastewater advanced treatment and efficient recovery utilization technology. Brinewastewater from a brine wastewater recycling unit flows through a nanofiltration unit, and is further subjected to treatment of an oxidized unit, an evaporation concentration unit, a sodium sulfate freezing crystallization unit, a mirabilite melt crystallization unit, a reverse osmosis unit, a high concentration EDM device I, a sodium chloride evaporative crystallization unit, a carnallite dryingunit, the treatment cost of the brine wastewater is significantly lowered, recycled water can serve as circulating water, a sodium sulfate sodium chloride industrial salt and carnallite are obtained,zero discharge of the brine wastewater is achieved, and environmental pollution is reduced.

The invention belongs to the technical field of polluted wastewater treatment, and specifically relates to a system and a treatment process for purification and salt separation of electroplating high-salt wastewater. The system comprises a high-salt wastewater pretreatment unit, a filtration treatment unit and an evaporation crystallization unit. The treatment process comprises the following steps: 1) high-salt wastewater pretreatment: a step of treating ammonia nitrogen, COD, organic matters and cyanide in wastewater, and allowing metal substances in the wastewater to be precipitated; 2) filtration treatment: a step of subjecting the wastewater to membrane filtration so as to obtain ultra-concentrated wastewater and a filtrate; 3) reverse osmosis treatment: a step of subjecting the filtrate to reverse osmosis filtration so as to obtain a filter residue and reflux reclaimed water; and 4) evaporation crystallization treatment: a step of allowing the filter residue to undergo pH value adjustment and crystallization treatment by using a heat-pump low-temperature evaporation technology and adding an inducing seed crystal so as to recover crystalline salt. According to the invention, byadoption of the heat-pump low-temperature evaporation technology, energy consumption is greatly saved; and a salt product and circulating reclaimed water are obtained, so zero discharge and resourceful utilization of the wastewater can be realized, and the purpose of circular economy is reached.

The invention discloses a production system and a production process for continuously preparing anhydrous sodium sulfate in acid bath. The production system comprises a multistage flash evaporation device, an evaporator and a rotary airflow dryer; the multistage flash evaporation device is communicated with the evaporator through a preheater; the evaporator is communicated with a ripening tank; the ripening tank is communicated with a first-stage thickener; the first-stage thickener is communicated with a first-stage centrifugal machine; the first-stage centrifugal machine is communicated witha neutralizing tank; the neutralizing tank is communicated with a second-stage thickener; the second-stage thickener is communicated with the rotary airflow dryer; and by the production method of theproduction system, production of the anhydrous sodium sulfate is completed through multiple steps. The production system provided by the invention produces the anhydrous sodium sulfate by cooperatingthe multistage flash evaporation device and the evaporator with the rotary airflow dryer, so that the process flow route is shortened and the energy consumption is reduced; and meanwhile, sodium sulfate crystal particles obtained through production have large size, the crystal particles are uniform and full, and the apparent quality of the anhydrous sodium sulfate is high.

The invention discloses a method for efficiently treating fluorine-containing waste electrolyte, which comprises the following steps: adding an additive and a reaction aid into the waste electrolyte, uniformly mixing, grinding to below 0.355 mm, roasting, cooling at a specific rate, crushing and washing to obtain an aluminum fluoride product, and concentrating filtrate to further extract other byproducts. According to the invention, the reaction aid is added to reduce the primary crystal temperature of the system, so that the reaction is carried out in a molten state, the mass transfer efficiency is high, the reaction conversion rate is high, and the content of effective aluminum fluoride in the product is high; meanwhile, the heat preservation time and the cooling rate are further controlled, so that aluminum fluoride grains generated by the reaction grow up, the obtained aluminum fluoride is good in flowability and can be well compatible with automatic discharging equipment of the current industrial aluminum electrolysis cell, and green and sustainable development of the electrolytic aluminum industry is achieved.

The invention relates to a method for producing sulphate of potash granulates, wherein 0.1 to 7.5 wt % of a sodium salt selected from among sodium chloride, sodium sulphate, sodium sulphate hydrates, sodium hydroxide and mixtures thereof are added to the sulphate of potash during the granulation process, the percentage by weight being in relation to the sulphate of potash used. In addition, 0.1 to 2.5 wt % of water are added prior to or during the granulation process. The invention also relates to the granulates obtained by said method as well as the use of sodium salts and glaserite and mixtures thereof for improving the mechanical properties of sulfate of potash granulates. The sulphate of potash granulates produced by the method of the invention have significantly greater bursting strength and significantly greater abrasion resistance than granulates known from the prior art.

The invention relates to the technical field of chemical engineering, and discloses a system and method for preparing byproduct potassium sulfate product through hydrothermal denitration of potassium chloride brine, and the method comprises the following steps: a nanofiltration membrane unit receives dechlorinated light salt brine from an external potassium alkali device and conveys the dechlorinated light salt brine to a heat exchange unit for heat exchange; secondary gas condensate generated by an evaporative crystallization unit is conveyed to the heat exchange unit, in the heat exchange unit, the dechlorinated light salt brine exchanges heat with the secondary gas condensate, the dechlorinated light salt brine after heat exchange is conveyed to the evaporative crystallization unit to be evaporated and concentrated to obtain potassium sulfate crystals, and the secondary gas condensate after heat exchange is subjected to waste heat recovery treatment; and potassium sulfate crystals are treated by a centrifugal separating unit and then enter a drying unit to be dried, qualified potassium sulfate products are obtained, and centrifugal mother liquor obtained after centrifugal separating is output to a potassium alkali device to enter a secondary brine refining procedure. According to the method, the defects of a barium-method denitration process or a calcium-method denitration process used in current industrial production are effectively overcome, and the purposes of reducing cost and improving efficiency are achieved.

The invention provides a quality-based and salt-based treatment device and method for coal chemical industry high-salinity wastewater. The coal chemical industry high-salinity wastewater is treated by adopting efficient hardness removal filtration, catalytic ozonation, ultrafiltration, efficient nanofiltration electrodialysis, reverse osmosis and evaporative crystallization, and by adopting the technology, a low-temperature heat source is effectively utilized, and near-zero emission and resource utilization of the coal chemical industry high-salinity wastewater are realized. Compared with the prior art, the process provided by the invention has the advantages of good effluent quality, high quality of recovered salts and good technical economy.

The invention relates to a method of preparing funnel-shaped sodium sulfate from high salt wastewater. The method comprises the following steps: heating the wastewater to 50-80 DEG C, adding sodium hydroxide to adjust the pH of the wastewater to 11-14, and controlling the stirring rate at 100-400 rpm; adopting a negative evaporative crystallizing mode till the volume of the evaporated water is 20-30% of original wastewater volume, wherein the vacuum degree is 0.04-0.07 MPa; and filtering and drying the obtained product to obtain the funnel-shaped sodium sulfate. The cone angle of the funnel ofthe sodium sulfate product with a special funnel-shaped crystal form is 120-150 degrees and the purity of sodium sulfate is greater than or equal to 95%. The granularity of particles is relatively great and the particles are distributed uniformly, and the grain size of the product is greater than or equal to 300 [mu]m.

The invention discloses a preparation method of large-particle spherical sodium sulfate crystals. The preparation method comprises the following steps: at 35-50 DEG C, preparing a sodium sulfate aqueous solution with a certain concentration, wherein the mass ratio of solute sodium sulfate to water is 0.2: 1 to 0.45: 1; preparing a mixed solvent of an organic solvent and a bridging agent at the same temperature, wherein the mass ratio of the organic solvent to water is 1: 1 to 3: 1, and the volume ratio of the bridging agent to solute sodium sulfate is 0.5: 1 to 1: 1; then, dropwise adding a sodium sulfate aqueous solution into the organic solvent-bridging agent mixed solvent at a speed of 0.5-4%/min to separate out crystals, and continuously stirring; and after dropwise adding, keeping stirring for 0.5-5 hours; and filtering, washing and drying to obtain the spherical sodium sulfate crystals. The sodium sulfate crystals prepared by the method are good in sphericity degree and large inparticle size, and the average particle size is greater than 600 [mu]m; and the filtering performance is good, the flowability is high, caking is not likely to happen, the product production efficiency can be improved, and the caking phenomenon in transportation and storage is reduced.

The invention discloses a high-salinity wastewater evaporative crystallization system which comprises a sodium sulfate crystallization unit, a first sodium chloride crystallization unit, a second sodium chloride crystallization unit and a carnallite crystallization unit. The high-salinity wastewater evaporative crystallization method comprises the following steps of (1) first sodium sulfate evaporative crystallization and freezing crystallization, (2) first sodium chloride evaporative crystallization, (3) second sodium chloride evaporative crystallization, and (4) carnallite evaporative crystallization. The method has the advantages that sodium chloride is subjected to two-stage salt production, and sodium chloride with different purities is produced; 2, sodium sulfate is subjected to evaporative crystallization and freezing crystallization in sequence, so that freezing crystallization blockage caused by direct freezing crystallization of a high sulfate radical solution can be avoided, most of sodium sulfate can be separated out, and the yield of sodium sulfate is increased; and 3, mirabilite produced by freezing crystallization can be conveyed to sodium sulfate evaporative crystallization and can also be directly conveyed to a sodium sulfate evaporative crystallization thickener, so that the investment and treatment cost are reduced.

The invention provides a sodium sulfate TVR single-effect evaporation and crystallization system which comprises a mother liquor tank, a centrifuge, a preheater, a TVR compressor, a cooling crystallizer and a condenser, wherein the mother liquor tank, the preheater, the cooling crystallizer and the centrifuge are sequentially connected. The system has a simple structure and a small floor area, and mother liquor can be cyclically evaporated and crystallized, so that the utilization ratio is high.

The invention discloses an electrolytic manganese electrolyte salt residue salt separation method and system, and belongs to the field of wastewater treatment, and the system comprises a dissolving tank, a filter press, a primary buffer tank, a primary cooling crystallization system, a first centrifugal machine, a secondary vacuum crystallization system, a second centrifugal machine, a secondary buffer tank, a tertiary high temperature crystallization system, a filter press kettle and a concentrated discharge drying system. No agent is added, inorganic components of the electrolytic manganese residues are extracted according to basic physical properties of solid waste and physical separation, and the operation cost is low; inorganic salt is separated in a mother liquor circulation mode, the waste liquor discharge amount is small, and meanwhile a large amount of water resources are recycled. According to the method, the multi-component elemental salts (ammonium, magnesium and manganese) in the manganese slag are recovered in sequence instead of single-component salt recovery in the electrolytic manganese waste slag, the recovery rate is high, and the solid waste reduction treatment degree is high; the electrolytic manganese waste residue inorganic salt separation equipment mainly comprises a reactor and an evaporator, and is simple in system, low in equipment investment and easy to industrialize.

The invention discloses a waste salt resource utilization brine deep refining method which comprises the following steps: 1, conveying waste salt into a salt dissolving barrel, adding water, stirring and dissolving to obtain crude brine; 2, the crude brine obtained in the step 1 is put into a silicon removal and hardness removal system, a chemical agent is added, and effluent of the silicon removal and hardness removal system contains part of ash and small particles of calcium salt and magnesium salt which are not completely settled. According to the method, the incinerated waste salt is subjected to silicon removal, hardness removal, advanced oxidation, resin adsorption and other treatments, the obtained brine effluent can be subjected to evaporation treatment, the condensate can be recycled to a crude salt dissolution section, the evaporated and crystallized salt is a product, the whole set of advanced treatment process ensures the product quality of the evaporated and crystallized salt, the reasonable recycling of the waste salt is realized, the environmental pressure is relieved, and the economic value is very good.