11 results about "Solvay process" patented technology

The invention relates to the technical field of chemical equipment, and discloses a sodium carbonate production system adopting an ammonia-soda process. The system for producing sodium carbonate by the ammonia-soda process comprises a thin liquid distillation tower and a flash evaporation module. The thin liquid distillation tower is used for discharging waste thin liquid; the flash evaporation module comprises a second flash evaporation device and a water injection assembly; a steam outlet of the second flash tank is communicated with a steam inlet of the thin liquid distillation tower; the water inlet end of the water injection assembly is communicated with the thin liquid distillation tower, and the water outlet end of the water injection assembly is located in the second flash tank and used for discharging waste thin liquid to flush flash steam in the second flash tank. According to the invention, by arranging the water injection assembly, the waste thin liquid discharged from the thin liquid distillation tower is introduced into the second flash tank for flushing flash steam in the second flash tank so as to flush away droplets in the flash steam, and the content of calcium ions introduced into the thin liquid distillation tower can be reduced, so that the calcium ions in the waste thin liquid are reduced and even eliminated; and the waste thin liquid discharged from the thin liquid distillation tower can be used as filtering washing water.

The application discloses a method for treating and utilizing large-particle waste sand in ammonia-alkali method alkali waste liquid, and the process is as follows: treating the large-particle waste sand, reducing the content of soluble salt in the waste sand through water washing, controlling the content of soluble salt in the waste sand to be less than or equal to 2%, designing the mixing proportion of the waste sand lime cement soil, replacing the soil in the cement lime soil with different amounts of waste sand, keeping the mass ratio of the admixture lime and cement unchanged in each test, and decreasing the content of the soil corresponding to the waste sand proportion gradient; carrying out the compaction test on the materials in each group under different target moisture contents, obtaining the maximum dry density and the optimum moisture content of the sample; determining the waste sand replacement interval of the waste sand lime cement soil meeting the strength and the optimum proportion of the waste sand lime cement soil material; and preparing the waste sand lime cement soil for paving the roadbed or the base of the road. The application solves the phenomenon of pipe grinding in the process of filling the well with the alkali waste liquid, prepares the road material according to the designed proportion of the large-particle waste sand and the lime soil, reduces the cost of the alkali waste liquid, and changes the large-particle waste sand into the road raw material.

The invention belongs to the technical field of sodium carbonate production by an ammonia-soda process, and particularly relates to a method for producing sodium carbonate by using refined brine prepared from concentrated brine, which comprises the following steps: sequentially feeding brine into ultrafiltration, nanofiltration and electrodialysis systems for impurity removal and concentration to obtain concentrated brine; adding limestone and coke into a lime kiln, calcining to obtain quick lime and kiln gas, and mixing the quick lime with the lime melting water to obtain lime milk; and adding the crude salt into the concentrated brine to prepare saturated crude brine, sequentially adding lime milk, a settling aid and a sodium carbonate solution, clarifying and settling to obtain refined brine, and feeding the refined brine into a sodium carbonate production system for producing sodium carbonate. The refined brine is prepared from the concentrated brine, the addition amount of crude salt is reduced, the calcium and magnesium carrying-in amount is reduced, and then the multiple beneficial effects of reducing the using amount of brine lime milk, improving the working condition of a lime kiln and the like are achieved.

The invention relates to the technical field of inorganic chemical industry, and particularly discloses an improved sodium carbonate production process by an ammonia-soda process, which comprises the steps of carbonization alkali precipitation, ammonia-sodium separation, ammonia regeneration, magnesium extraction, calcium separation and the like. Meanwhile, resources such as water resources, ammonia and carbon dioxide are recycled, and the method is suitable for large-scale industrial soda ash production enterprises, meets the environment-friendly requirement and the efficient resource utilization requirement, and can be widely applied to the industrial fields of chemical engineering, building materials, food processing and the like which depend on soda ash and calcium-magnesium byproducts.

This invention belongs to the field of ammonia-soda process soda ash production technology, specifically relating to a method for preparing low-turbidity refined brine. The method involves sending calcium-removed brine into a clarification tank for clarification and sedimentation to obtain a supernatant, which is then pressurized and filtered through a microfiltration membrane device to obtain low-turbidity refined brine. The microfiltration membrane device includes a first chamber and a second chamber. Several high-density polyethylene microfiltration membrane filter elements are vertically arranged in the second chamber to connect the first and second chambers. The microfiltration membrane filter element has a double-layer structure including a filter layer and a support layer. This invention utilizes an asymmetric double-layer rigid membrane material sintered from high-density polyethylene of different particle sizes to form a precise pore size filtration channel. Combined with an efficient backwashing mechanism of online gas washing and acid washing, this achieves long-cycle, low-cost operation of the device.

The invention discloses a preparation method of high-purity high-whiteness dihydrate gypsum. The preparation method comprises the following steps: (1) respectively refining calcium chloride waste liquid produced by an ammonia-alkali method and byproduct mirabilite liquid of a chemical fiber factory; (2) carrying out chemical reaction on the two refined salt solutions in a reactor; and (3) washing and purifying to prepare the dihydrate gypsum with the whiteness of more than 92% and the purity of more than 99%. According to the invention, the calcium chloride waste liquid generated by an ammonia-soda process sodium carbonate process and the mirabilite waste liquid generated by the chemical fiber industry are used as core raw materials, and the product has stable and uniform performance, can be directly used as a high-quality raw material, widely replaces natural gypsum and common industrial byproduct gypsum, and is applied to the field with extremely high requirements on impurity content, color and stability.

The invention belongs to the technical field of ink printing, and discloses a green, environment-friendly and waste-reducing printing process with excellent finished product quality. The printing process comprises the following steps: (1) ink preparation: mixing waste residues of sodium carbonate prepared by a modified ammonia-alkali method, diisocyanate, polymer polyol, a chain extender, a catalyst and a pigment, and then adding water for emulsification to obtain ink; and (2) ink printing: carrying out ink printing on the printing base material, and then curing to obtain the printed product. The waste residue of sodium carbonate prepared by a modified ammonia-alkali method is added, so that the solid waste is utilized, meanwhile, the waste residue is used as a filler of the ink, the curing speed of the obtained ink and the adhesive force of the cured ink on a printed substrate can be remarkably improved, and the service life of a printed product is prolonged. According to the printing method, resources can be saved, a large amount of solid waste is used, and pollution of the solid waste to the environment is reduced.

This invention discloses a start-up and shutdown process for a mother liquor distillation tower to reduce ammonia consumption, relating to the field of ammonia-soda alkali production technology. The waste supernatant used in this invention is the supernatant of distillation waste liquid, with characteristic indicators similar to the distillation waste liquid: temperature 70-80℃, ammonia content of approximately 70 mg / L. Replacing the relatively low-temperature circulating water in the original start-up and shutdown process with this waste supernatant allows for the addition of a larger amount of waste supernatant while using the same amount of steam. This solves the problem of high ammonia levels in the waste liquid due to gas-liquid imbalance caused by small influent flow during the initial start-up and shutdown phases. Furthermore, the ammonia content in the waste supernatant itself reduces ammonia loss during start-up and shutdown. Using this start-up and shutdown process for distillation tower switching operations, the operation is stable. The ammonia content in the start-up waste liquid and the boiling water after shutdown is reduced to an average of approximately 100 mg / L. Statistical analysis shows that using this process for distillation tower switching reduces ammonia loss to approximately 0.5 t per cycle.

The present invention provides a method and apparatus (2a) for producing at least one of calcium oxide, magnesium oxide and an iron oxide from an ore comprising a carbonate mineral of at least one of calcium, magnesium and iron, such as limestone and siderite ores. The method comprises producing liquid sodium and chlorine gas by electrolysis. The liquid sodium is oxidised to sodium oxide and the chlorine is used to make hydrochloric acid. The sodium oxide may be produced in a redox reaction with an oxide of another metal to produce the other metal in elemental form as well. The ore is added to the hydrochloric acid to dissolve the carbonate mineral therein, which produces gaseous carbon dioxide and an aqueous solution respectively comprising at least one of calcium chloride, magnesium chloride and ferrous chloride. The carbonate mineral is dissolved in the hydrochloric acid closed off from their surrounding environment and the carbon dioxide is captured. The aqueous solution is reacted with at least some of the sodium oxide, or sodium hydroxide derived therefrom, to produce an aqueous solution of sodium chloride and a precipitate respectively comprising at least one of calcium hydroxide, magnesium hydroxide and ferrous hydroxide. The precipitate is then phase separated from the aqueous solution of sodium chloride and the hydroxide(s) in the separated precipitate are thermally decomposed to produce water vapour and a solid end-product comprising the desired oxide(s). Sufficient heat for this thermal decomposition is transferred to the separated precipitate from at least one of the electrolysis products, the exothermic processes by which the precipitate is produced, their respective products and the products of the thermal decomposition itself. Thus the invention consumes no carbonaceous fuel, including any fossil fuel, and has electricity as its only energy requirement. If the electricity is produced from a source of renewable energy, it produces no greenhouse gas emissions. The apparatus (2a) comprises an electrolytic subassembly (10), a sodium oxide or hydroxide-producing subassembly (13), a hydrochloric acid-producing subassembly (12), a reaction subassembly (14), a solid-aqueous phase separator (16), a kiln (20), and a heat transfer pathway (23) for transferring enough heat to the precipitate in the kiln (20) to cause the thermal decomposition from at least one of: a product of the electrolytic subassembly (10), the other subassemblies (12, 13, 14) and their respective products, and a product of the thermal decomposition. The invention is intended to replace the traditional calcination process, including for the production of cement clinker, and can also be used to convert siderite ores into one or more iron oxides suitable for ironmaking. The captured carbon dioxide may be reacted with a second portion of the sodium oxide, or with sodium hydroxide derived therefrom, to produce sodium carbonate, thereby also providing a replacement for the Solvay process. In some embodiments, the method can even have a negative carbon footprint overall.

The invention provides a method and device for preparing a desulfurizing agent by recycling ammonia alkali white mud, and the method comprises the following steps: (1) carrying out solid-liquid separation treatment on a solid-liquid mixed-phase raw material containing the white mud in waste discharge of sodium carbonate produced by an ammonia alkali method to obtain a white mud filter cake containing Mg (OH) 2, CaCO3 and Ca (OH) 2; (2) scattering the white mud filter cake to obtain desulfurizer intermediate particles; (3) uniformly mixing the slurry mixing liquid with the intermediate particles, and then carrying out ball milling treatment to obtain a crude product of the desulfurizing agent; and (4) carrying out desanding separation treatment on the desulfurizer crude product to prepare the desulfurizer with low salt, high fineness and high solid content, thereby recycling the ammonia alkali white mud.

The application discloses a method for comprehensive utilization of soda waste clear liquid and salted salt post bitter brine. The salted salt post bitter brine and ammonia distillation waste liquid are pretreated through an ultrafiltration membrane, the bitter brine and the ammonia distillation waste clear liquid are mixed in proportion, the obtained calcium sulfate dihydrate suspension liquid is subjected to solid-liquid separation, the liquid after centrifugation is subjected to an electrodialysis stage, and magnesium chloride solution and sodium chloride solution are obtained through the electrodialysis; the solid after centrifugation is washed, pressure-filtered, and then made into a slurry, a crystal modifier is added for crystal transformation, and through centrifugation and drying, calcium sulfate hemihydrate whiskers are finally obtained. The method uses the salted salt post bitter brine and the ammonia distillation waste clear liquid as raw materials to produce the calcium sulfate hemihydrate whiskers, and the two low-grade solutions of the magnesium chloride solution and the sodium chloride solution are reused, so that the high-value-added products are produced, no waste water is discharged, and the ecological environment and the economic benefits are both won.