58 results about "Solvay process" patented technology

The invention provides a method for the combined production of ammonia and basic calcium chloride by decomposing ammonium chloride, which comprises the following steps: grinding or crushing calcareous materials and ammonium chloride according to a mol ratio of 1:0.5-2 in a ball grinder or a crusher at -20-200 DEG C, enabling the calcareous materials and the ammonium chloride to be subject to a chemical reaction to decompose the ammonium chloride so as to release ammonia gas and generate basic calcium chloride. The invention fully uses the large amount of ammonium chloride as the byproducts of the combined soda process and the ammonia soda process, realizes the recycling of ammonia and generates the basic calcium chloride as the byproduct. The invention has the characteristics of simple process, low investment, high conversion rate, no pollution and low energy consumption, is applicable to industrial production and meets the requirements green chemical development in the present society.

Belonging to the technical field of solid waste miscellaneous salt recycling treatment, the invention discloses a method for preparation of sodium bicarbonate and ammonium sulfate from chemical strong brine. According to the method, evaporated and concentrated chemical strong brine is subjected to hardness removal to obtain a delicate mirabilite solution, and then ammonia-soda process reaction is carried out to obtain sodium bicarbonate and ammonium sulfate products. The method provided by the invention solves the difficult treatment problem of chemical strong brine, realizes recycling of miscellaneous salt in strong brine, and meets the sustainable development requirements. At the same time, compared with the salt method for preparation of sodium bicarbonate, the method provided by the invention reduces the anti-corrosion requirement of equipment, saves the project investment for preparation of sodium bicarbonate, has the byproduct ammonium sulfate with a value higher than ammonium chloride, and has obvious advantages in economic benefits.

The invention relates to a method for preparing high-purity dihydrate gypsum whiskers by using an industrial byproduct calcium chloride. The method comprises the following steps: 1) preparing a calcium chloride solution from an ammonia-soda-process industrial byproduct calcium chloride slurry, heating the calcium chloride solution to 30-80 DEG C, and adding a nucleation accelerator and a crystal form control agent to obtain a reaction mother solution; and 2) adding a 40-60-DEG C sodium sulfate solution into the reaction mother solution, stirring to react for 30-40 minutes, keeping the temperature for 0.5-3 hours to obtain a dihydrate gypsum whisker slurry, and carrying out after-treatment to obtain the high-purity dihydrate gypsum whiskers. The surplus byproduct in the salt chemical industry production process is used as the raw material to prepare the dihydrate gypsum whiskers, of which the length-diameter ratio is 10-100, the crystal length is 50-500 mu m, the purity is 98% or above and the whiteness is 90 or above. The invention provides a high-added-value utilization scheme for the calcium chloride slurry byproduct; and the obtained gypsum whisker can be widely used in the fields of papermaking, chemical industry, novel construction materials, composite materials and the like.

The invention discloses a method used for pyrolyzing wet oxidation desulfurization mixed waste liquid in partial oxidation environment. According to the method, a desulfurization waste liquid mixture obtained via ammonia alkaline method and sodium alkali method is filtered; an obtained filtrate is subjected to reduced pressure vaporization preheating, a desulfurization waste liquid concentrated solution obtained via vaporization is subjected to pressurization, is subjected to atomization using a three-channel combined pressure atomization nozzle, and then is delivered into a pyrolysis reactor together with hydrogen-rich gas, such as coal gas, and oxygen for pyrolysis; pyrolysis gas obtained via pyrolysis is subjected to vaporization preheating of desulfurization waste liquid via a direct method or an indirect method; pyrolyzed molten salt obtained via pyrolysis is discharged via the bottom of the pyrolysis reactor, is cooled using a cooling system, and then is recycled back to a desulfurization workshop section to provide alkali sources. The method is simple; operation is continuous and stable; application range is wide; desulfurization waste liquid obtained via ammonia alkaline method and sodium alkali method, and a mixture of desulfurization waste liquid obtained via ammonia alkaline method and sodium alkali method can be processed effectively; all-component harmless treatment of waste liquid is realized, and problems that mixed waste liquid is difficult to process, processing processes are complicated, and application range is limited, are solved completely.

The proposed invention uses industrial byproducts such as fly ash in an ion exchange/reverse osmosis (IE/RO) patented technology to sequester carbon dioxide CO2 gas and produce 6 to 7% sodium carbonate (Na₂CO₃) liquor. Similar materials encompass alkaline Fly Ash (AFA) liquor, alkaline red mud (ARM), coal ash, wood ash, and similar natural byproduct materials that are rich in metallic oxides. The process uses AFA or ARM at the input of an IE/RO process where the hydroxides (OH″) get extracted and concentrated for CO₂ gas sequestration. The remaining insoluble byproduct material is used in civil works such as construction and road industry. Ion exchange modules are used to remove all multivalent ionic impurities while a reverse osmosis (RO) skid concentrates the carbonated liquor up to 6 to 7% liquor (or 10% in advanced RO). The process is not an electrochemical chloro-alkali battery nor related to the ammonical Solvay process. The invention is inherently harnessed for carbon capture in the production of soda chemicals from waste alkaline byproducts. There are similarities in the hardware of patent # WIPO Patent App. No. PCT/IB2009/007713.

The invention discloses a method for removing chloride ions in waste alkaline residues. The method specifically includes the steps that the waste alkaline residues and magnetic substances are evenly mixed according to the mass ratio of 100:0.1-1.5; water with the mass three to six times that of the waste alkaline residues is added; the mixture is fully stirred, water elution, dechlorination and solid-liquid separation are conducted, and then deposits and supernate are obtained; the deposits are dried; and the magnetic substances are removed through a magnet, and then dechlorinated alkaline residues with 90-93% of chloride removed is obtained. The method has the beneficial effects that the settling velocity of the alkaline residues is high, the alkaline residue dechlorination efficiency is high, and the water content of the dechlorinated alkaline residues is low. Meanwhile, the process and equipment are simple, operation is easy, and energy consumption is low. By means of the method, the waste alkaline residues in soda production by the ammonia-soda process are applied to broader fields in a large scale.

The invention discloses a method for making a cored building material block by using solidified soda residue soil, belonging to the field of civil engineering. The cored building material block is prepared from a solidified soda residue soil core material, a mortar or concrete external coating material and an internal division wall through the steps of solidified soda residue soil core material making, mortar or concrete making, pressure forming, curing and the like. The solidified soda residue soil is a hardenite which has certain strength, is capable of fixing harmful substances in soda residue soil to reduce or eliminate the harmful substance leaching phenomenon along with water and is formed by uniformly blending a curing agent and soda residues (waste residues of waste liquid discharged in the process of producing soda by using an ammonia-soda process) and subjecting the curing agent and the soda residue soil to a physical-chemical reaction. Waste liquid and waste residues discharged in the industrial production process of soda are effectively utilized, and the reduction, harmlessness and reclamation of the soda residues are realized.

The invention relates to a method for producing sodium carbonate, in particular to a method for producing sodium carbonate by utilizing chlor-alkali ammonia-alkali tailings. Limestone burns to emit heat, and is resolved to generate carbon dioxide gas which is sent to a compressor; the acetylene sludge slurry of the chlor-alkali tailing and calcium carbide dust are mixed to prepare lime slurry; refined salt water is prepared through light salt brine after production of chlor-alkali and mirabilite; light ammoniacal brine is sent to an absorption tower to prepare ammoniacal brine; sodium bicarbonate slurry is sent to a filtering alkali vehicle for solid-liquid separation; the solid body is sent to a sodium bicarbonate calcination procedure; the liquid is sent to a mother liquid distillation procedure; the sodium bicarbonate is conducted by heating resolving in a sodium bicarbonate calcination furnace to generate sodium carbonate, and is sent to a sodium bicarbonate production and alkali cooling procedure; the generated carbon dioxide gas returns to a carbonizer. The method produces sodium carbonate by utilizing the carbon dioxide emitted by the ammonia-alkali and the acetylene sludge slurry emitted by the chlor-alkali, realizes combined production of the two alkalis, solves the problem of emission of the alkali wastes, reduces consumption of limestone and energy, improves the utilization ratio of the carbon dioxide, and improves the production of sodium carbonate through an ammonia soda process.

The invention belongs to the technical field of wastewater treatment and provides a new method for recycling ammonia distillation wastewater discharged during production of soda ash by virtue of an ammonia-soda process. The new method comprises the following steps: clarifying the ammonia distillation wastewater, and filtering, so that clarified liquor and solid waste residue are obtained; adding excessive lime milk into the clarified liquor, carrying out causticizing reaction, and obtaining magnesium hydroxide floating on liquid surface and slurry after the causticizing reaction is finished; respectively adding the slurry and excessive refined mirabilite aqueous solution into a gypsum reactor, fully reacting, filtering products, and washing, so that a dehydrate gypsum filter cake and turbid liquid containing sodium chloride and calcium hydroxide are obtained; carrying out dust removal and desulfurization purification treatment on carbon dioxide waste gas, introducing into a carbonization tower, carrying out carbonation reaction with calcium hydroxide in the turbid liquid, settling, and filtering, so that a light calcium carbonate filter cake and sodium chloride clear liquid are obtained; and applying the sodium chloride clear liquid to an alkali making system, so that sodium chloride in the clear liquid is recycled. The new method provided by the invention solves the technical problem that waste produced in a soda ash production process by virtue of the ammonia-soda process in the prior art cannot be comprehensively utilized.

The invention relates to a method for preparing sodium carbonate from sodium sulfate. The method comprises, based on the original ammonia-soda process for sodium carbonate preparation, clarifying to remove impurities in an ammonia distillation mother liquor, stirring the ammonia distillation mother liquor at a temperature of 30-65 DEG C, according to calcium chloride content, adding sodium sulfate into the ammonia distillation mother liquor according to a mole ratio of calcium chloride to sodium sulfate of 1: 1-1.1, carrying out a reaction process to obtain sodium chloride and gypsum (CaSO4. 2H2O) precipitates, carrying out filtration to obtain unsaturated primary brine and carrying out later ammonia-soda process-based production. The method utilizes sodium sulfate as a raw material, utilizes chloride ions and ammonia as intermediate mediums, realizes resource cyclic utilization, reduces waste water generation and is very important. The method can reduce sodium carbonate production wastes, utilizes sodium sulfate or saltcake raw ore as production raw materials, reduces enterprise water consumption and waste water discharge, reduces solid waste production and improves enterprise economic benefits.

The invention relates to a process of ammonia-soda-combined-soda cyclic production for sodium chloride, sodium carbonate, liquid ammonia, ammonium chloride, calcium chloride and calcium carbonate. The process comprises the following steps: using brine, carbon dioxide and acetylene sludge as raw materials for producing sodium carbonate by an ammonia-soda method, injecting the generated waste liquid in a salt well and extracting brine, leaving and storing the calcium sulphate generated after nitrate removal and the injected soda sludge in the salt well, conveying the extracted brine into a salt calcium co-production device, producing a solid salt, reacting a part of the remainder solution with sodium carbonate to produce calcium carbonate, using a part as liquid calcium chloride, and evaporating the other part to produce calcium chloride dehydrate; using the obtained solid salt, ammonia and carbon dioxide as raw materials for producing sodium carbonate and ammonium chloride by a combined-soda method; adding wet ammonium chloride in the ammonia-soda waste liquid and decomposing. According to the process, the efficiency and yield of cyclic production are increased, and environmental pollution is reduced; the purities of sodium carbonate, calcium carbonate, ammonium chloride and solid salt are up to 99.0%, 99.9%, 99.5% and 95% respectively, the content of solid calcium is 74%, liquid calcium can be optimally configured, and the particle size of calcium carbonate is nanometre-submicron order.

The invention relates to a brine preparation technique, particularly a brine refinement technique. The technique comprises the following steps: adding crude brine, lime milk and a sodium sulfate solution into a primary reactor, and mixing to react in the reactor; sending the reaction solution in the primary reactor to a primary brine settling tank through a chute, carrying out solid-liquid separation on primary refined brine and brine sludge in the primary brine settling tank, sending the clear primary refined brine from the upper part of the primary settling tank to a secondary refinement reactor to perform calcium removal; sending the brine sludge discharged from the top of the primary brine settling tank and silt discharged from the primary reactor into a sludge washing barrel to be washed, and recovering raw salt; and when different degrees of calcium sulfate scales are formed on the equipment and pipelines after the sulfate content in the sodium sulfate solution increases, adding causticized low-concentration alkali liquor into the primary brine settling tank to eliminate the scales. The technique avoids the scales of the production equipment system and improves the lime-sodium carbonate brine refinement method from sodium carbonate by an ammonia soda process.

The invention discloses a method for preparing engineering soil from alkaline residues by an ammonia-alkaline process. The method comprises the step of: sequentially carrying out sediment treatment, concentration treatment, homogenization modification, dehydration treatment and stacking treatment on alkaline residues to obtain engineering soil, wherein the homogenizing modification comprises the following specific steps: adding a calcium material and a volcanic ash active material into the concentrated alkaline residues, and uniformly stirring the mixture; and the mass ratio of dry substancesin the calcium material, the volcanic ash active material and the concentrated alkaline residues is (0-15): (5-20): 100. The method has the advantage of improving the strength and water stability of the engineering soil prepared from the alkaline residues.

The invention relates to the technical field of soda production, in particular to a method and a device for recycling waste clear liquid produced in a process for producing sodium carbonate by an ammonia-soda process. The method for recycling the waste clear liquid comprises the following steps of: leading the waste clear liquid into a waste liquid tank; starting a compression device to ensure that negative pressure is formed in the waste liquid tank, and recycling according to a gas and liquid heat exchange principle to obtain distilled water; when water is evaporated to ensure the concentration of sodium chloride in the waste clear liquid is increased until sodium chloride precipitate is separated out, performing liquid-solid separation to obtain sodium chloride; and continuously pressurizing to compress the waste clear liquid to ensure that the concentration of calcium chloride in the waste clear liquid is increased until calcium chloride precipitate is separated out, performing solid-liquid separation to obtain calcium chloride. By the method, the chemical pollution of the waste clear liquid produced in the process for producing the sodium carbonate by the ammonia-soda process is eliminated, distillation waste liquid can be reformed into a chemical product with certain economic value, the negative pressure and pressurization principles are skillfully used, sodium chloride and calcium chloride in the waste clear liquid can be recycled, and distilled water can be extracted; and the method has the advantages of simplicity, low production cost, and high economic benefit.

The invention belongs to the technical field of mineral development, and particularly relates to a method for cyclically and comprehensively utilizing waste liquid generated in the process of preparing an alkali by an ammonia-alkali method. The method for comprehensively utilizing the waste liquid generated in the process of preparing the alkali by the ammonia-alkali method comprises the following steps: naturally settling the pretreated alkali-making waste liquid, and separating to obtain a light calcium liquid; mixing the light calcium liquid with a salt-making discharged mother liquor, and reacting to generate mixed slurry of calcium sulfate dihydrate and sodium chloride; pumping the mixed slurry into a settling tank by using a slurry pump, and thickening the solid content of the slurry to obtain thick slurry; and carrying out solid-liquid separation on the thick slurry to obtain afiltrate II and filter residues II, and washing the filter residues II with water to obtain gypsum, wherein the filtrate II is a high-concentration NaCl solution, and is injected into a mine well to be extracted. By means of the method, the situation that calcium sulfate generated underground deposits and covers mineral resources at the bottom of the well can be reduced, calcium sulfate and calcium carbonate products can be obtained in the circulation process, and mineral resources are more fully utilized.

The invention relates to the technical field of salt chemical engineering resource recycling, and particularly discloses a circulating green production method for salt, alkali and calcium on and underneath the ground. According to the method, calcium chloride in ammonia-alkali waste liquid and sodium sulfate and glauberite in a mirabilite type rock salt resource are mixed; waste liquid is treatedon the ground in stages, meanwhile, waste resources are reasonably utilized, and all resources such as Ca<2+>, Cl<->, SO4<2-> and Na<+> are recycled; and the problem of pollution caused by discharge of wastewater from a traditional ammonia-alkali process is solved, and cyclic utilization and green production of the resources are achieved.

The embodiment of the invention provides a comprehensive utilization method and equipment for producing soda ash residue by using an ammonia-soda process, which comprises the steps of adjusting the pH value of the soda residue to 6.5-7.5 by using hydrochloric acid, and converting calcium-containing and magnesium-containing components in the soda residue into corresponding chlorides; and carrying out dry-wet separation, repeatedly washing solids until the chloride ion concentration is 0.2% or below, adjusting the concentration of the generated liquid, and chelating with compound amino acid to form a compound amino acid chelated liquid/solid/body fertilizer, wherein the obtained solid sand ash is used for manufacturing cement clinker, a retarder, a baking-free brick, a solid fertilizer and/or a roadbed material. Various components of the soda residue are comprehensively utilized, and waste is turned into wealth.

A hydrogen fuel, sustainable, closed clean energy cycle based on green chemistry is presented for large scale implementation using a cost effective electrolytic cell. A chemical reaction between salinated (sea) or desalinated (fresh) water (H₂O) and sodium (Na) metal produces hydrogen (H₂) fuel and sodium hydroxide (NaOH) byproduct. The NaOH is reprocessed in a solar powered electrolytic Na metal production plant that can result in excess chlorine (Cl₂) from sodium chloride (NaCl) in sea salt mixed with NaOH, used to effect freezing point lowering of seawater reactant for hydrogen generation at reduced temperatures. The method and molten salt electrolytic cell enable natural separation of NaCl from NaOH, thereby limiting excess Cl₂ production. The recovered NaCl is used to produce concentrated brine solution from seawater for hydrogen generation in cold climates, or becomes converted to sodium carbonate (Na₂CO₃) via the Solvay process for electrolytic production of Na metal without Cl₂ generation.

The invention discloses a method for producing potassium sulphate fertilizer magnesium metal PVC and liquid chlorine hydrochloric acid through carnallite. According to the technical route, firstly, the carnallite is dissolved with water and then is crystallized, potassium chloride and magnesium chloride hexahydrate contained in the carnallite are separated and purified; then, the magnesium chloride hexahydrate is electrolyzed through the improved Norsk Hydro process to prepare magnesium metal and chlorine; thirdly, a potassium chloride solution and concentrated sulfuric acid are subjected to a chemical reaction under a heated condition to prepare potassium sulfate fertilizer and hydrogen chloride; finally, secondary products including chloride and hydrogen chloride are used for producing liquid chlorine PVC or hydrochloric acid; the sylvite production raw material carnallite can be comprehensively utilized fully. A method for producing sulfuric acid sodium carbonate through natural sulfate (magnesium sulfate and mirabilite) in sylvite residues, a solvay process for producing sodium carbonate and a calcium carbide method for producing PVC are commonly applied, a plant is reasonably planned and established beside a salt lake, scientific cooperative production is achieved, resources can be comprehensively and circularly utilized, energy is saved, emission is reduced, consumption is reduced, and the environment protection is achieved.

The invention relates to the technical field of soda ash production, and especially relates to a method for preventing the scabbing of a pre-liming tank in the distillation process in soda ash production by an ammonia-soda process. A return pipe is arranged on one side close to the bottom of a pre-liming tank. Lime milk and preheated mother liquor are stirred and mixed in the pre-liming tank to form blending liquid, which enters the pre-liming tank from a turbid liquid return pipe arranged at the upper part of the pre-liming tank through the return pipe. The method can prevent the pre-liming tank from scabbing, continuous and stable operation of the pre-liming tank is realized, the stability and continuity of a whole sodium carbonate production system are improved, the environmental protection risk is reduced, the equipment utilization rate is improved, the productivity is improved, and thus the manufacturing cost is reduced.

The invention provides a treating and utilizing technology of waste liquid from Solvay process. The treating and utilizing technology adopts waste liquid from Solvay process, stearic acid and caustic soda as raw materials; calcium chloride in the waste liquid from Solvay process is converted into a high-value product, namely calcium stearate; filtered waste liquid from Solvay process is sufficiently utilized in the process. According to the invention, comprehensive utilization of the waste liquid from Solvay process is realized sufficiently; the cost of calcium serving as a raw material in the production process of calcium stearate is reduced; the waste liquid discharging problem of the production process of calcium stearate is solved. Practical production tests show that to produce 1 ton of calcium stearate, about 2 tons of the waste liquid from Solvay process can be treated. The treating and utilizing technology has the advantages that the raw materials are wide in sources, and low in cost; the operability is high; industrialization is easy to realize; in the whole technological process, water is saved, consumption is reduced, and a higher comprehensive economic benefit can be realized.

The invention belongs to the technical field of salt and alkali industry preparation, and discloses a salt and alkali combined preparation process based on an ammonia-soda method. The preparation process includes the steps: removing nitrate and refining the nitrate; leading in ammonia gas to reach saturation, and leading in carbon dioxide; filtering out crystals and calcining the crystals; addingacetylene sludge into mother liquor, and distilling ammonia; pouring the mother liquor into a salt well; extracting brine and preparing salt. The preparation process has the advantages that alkali preparation of the ammonia-soda method and a well slat preparation process are combined, recyclable comprehensive utilization of waste residue and waste liquid is achieved, environmental pollution is greatly reduced, production cost is greatly reduced, and huge economic benefits are brought.

The invention discloses a method for producing a calcium chloride solution by using alkali production waste residues in an ammonia-alkali process, hydrogen chloride gas and the alkali production waste residues in ammonia-alkali process sodium carbonate production are used as raw materials, the calcium chloride solution is prepared through crushing/grinding size mixing and reaction in a two-stage reactor, and the concentration of the prepared calcium chloride solution can reach more than 50%. The content of magnesium ions and sulfate ions is greatly reduced, the steam consumption is greatly reduced when solid calcium chloride is produced through subsequent evaporation, concentration and crystallization, and meanwhile, the discharge amount of solid alkaline residues is reduced.