214results about "Product crystals bed crystallization" patented technology

In a process for the purification of a crude acrylic acid melt, the crude acrylic acid melt is converted, under the action of low temperatures, into a crude acrylic acid suspension consisting of acrylic acid crystals and residual melt, and the acrylic acid crystals of the crude acrylic acid suspension are freed from remaining residual melt in a wash column, the production of the acrylic acid crystals of the crude acrylic acid suspension being carried out in the presence of water, the wash column being a wash column with forced transport of the acrylic acid crystals and the wash liquid used being the melt of acrylic acid crystals purified in the wash column.

It is an object of the present invention to improve the phosphorus recovery rate in a method and apparatus for removing ions to be removed in a liquid to be treated by crystallizing out crystal particles of a poorly soluble salt of the ions to be removed in the liquid to be treated in a crystallization reaction tank. As one means for attaining this object, in one embodiment of the present invention there is provided a method for removing ions to be removed in a liquid to be treated by crystallizing out crystal particles of a poorly soluble salt of the ions to be removed in the liquid to be treated in a crystallization reaction tank, which comprises adding a chemical agent required for the crystallization reaction into a part of a treated liquid flowing out from the crystallization reaction tank and dissolving the chemical agent therein, and supplying the resulting solution into the crystallization reaction tank as a circulating liquid, wherein the liquid to be treated and the circulating liquid are introduced into the crystallization reaction tank tangentially to a transverse section of the crystallization reaction tank.

The invention relates to a desulfurization wastewater resourceful treatment method. The method comprises the following steps of 1, pretreatment, wherein suspended solids in desulfurization wastewater are removed; 2, concentration evaporation, wherein wastewater is subjected to evaporation treatment, in the initial stage of evaporation, calcium sulfate crystals are put into the wastewater, and after evaporation is ended, wastewater is cleared up; 3, crystallization evaporation, wherein the concentration of ions in wastewater is adjusted, crystallization points of the solution are made to fall into a crystallization region of a magnesium sulfate monohydrate salt or crystallization regions of magnesium sulfate monohydrate and sodium chloride salts, and then wastewater is subjected to evaporation crystallization; 4, crystallization salt separation, wherein the obtained mixed salt is separated to obtain a magnesium sulfate monohydrate crystallization salt and a sodium chloride crystallization salt. According to the desulfurization wastewater resourceful treatment method, the investment and operation costs are low, and two high-value industrial salts of magnesium sulfate and sodium chloride can be obtained.

The invention relates to a method for continuously preparing high-bulk density methionine crystals. The process of the method is as follows: a hydrolysate, which is obtained from reaction of 5-(beta-methylthioethyl)hydantoin and a potassium carbonate solution, is mixed with an outside circular material from a DTB neutralization crystallizer with a gas phase neutralization section, the mixture is cooled and enters a liquid distributor in a neutralization area in the upper part of the crystallizer, the mixture is sprayed in drops or trickles into carbon dioxide gas for neutralization reaction, and then falls naturally into a crystallization area in the lower part to be mixed with a material in the area, the mixture grows on tiny crystals in a system to form crystals with larger grain sizes, and meanwhile new crystal nucleuses are formed; in a deposition area in the middle part of the crystallization area, the crystals with larger grain sizes sink into a washing leg, the tiny crystals circulate along with the outside circular material, a part of the outside circular material is used for washing the crystals in the washing leg, and the other part of the outside circular materials is mixed with the hydrolysate; the crystals in the washing leg are separated, washed and then dried to obtain the high-bulk density methionine product.

A method is provided for making large, uniform and individual crystals from aqueous solutions including the steps of obtaining a concentrated aqueous solution by means of evaporation; rapidly cooling the solution from a post-evaporation high temperature to a first lower temperature, wherein the first lower temperature is lower than the post-evaporation high temperature and further wherein the first lower temperature is an isothermal crystallization temperature of said solution; generating a batch of initial nuclei by inducing nucleation at the first lower temperature and starting crystal growth; uniformly spreading the initial nuclei into a bulk solution; maintaining simultaneous and rapid growth of crystals from the nuclei at the first lower temperature for a predetermined length of time; continuing the growth of the crystals to produce large, uniform and individual crystals for a predetermined length of time at a temperature that varies gradually from between a first lower temperature to a second lower temperature, wherein the second lower temperature is a temperature lower than the first lower temperature and further wherein the second lower temperature is an end temperature of crystallization; and recovering the large, uniform and individual crystals. Parameters and a system for producing lactose monohydrate crystals using the method are also provided.

A system for removing selenium from a solid feed stream includes a selenium dissolver configured to selectively dissolve elemental selenium from the solid feed stream and to produce a selenium rich solution and a crystallizer coupled to the selenium dissolver and configured to receive the selenium rich solution from the dissolver, to add an acid to the selenium rich solution, to remove purified selenium from the selenium rich solution, and to remove sulfur dioxide from the selenium rich solution.

Methods of processing an aqueous solution comprising potassium sulfate and magnesium sulfate include crystallizing K₂SO₄, crystallizing recycle crystals, and mixing at least a portion of the recycle crystals with the aqueous solution. Systems for processing potassium sulfate and magnesium sulfate include a first crystallizer and a second crystallizer in fluid communication with the second mix tank. The second crystallizer is structured and adapted to precipitate recycle crystals from the concentrated liquor to form a potassium-depleted recycle brine. The recycle crystals precipitated in the second crystallizer have a composition suitable to be recycled to the first crystallizer to increase the production of SOP.

A device and method for simultaneously concentrating a plurality of samples in small volumes based on the principle of cystallization. The device comprises a device for concentrating a plurality of samples comprising: a first temperature control means (12) having a plurality of container means (40/50) for containing said plurality of samples; a second complementary temperature control means (11) having a plurality of conducting means (22) which are adapted to be inserted in respective samples in said plurality of container means (40/50); and insulating means (30) for insulating said first temperature control means (12) from said temperature control means (11) such than an amount of heat from said plurality of samples is dissipated through said plurality of conducting means (22).

A composition for reducing deposition of a mineral salt from an aqueous supersaturated solution onto a solid surface in contact with the aqueous supersaturated solution which composition comprises a dispersion of either (i) seed crystals of the mineral salt in an aqueous solution of the mineral salt or (ii) seed crystals of a salt isomorphous with the mineral salt in an aqueous solution of the isomorphous salt wherein the dispersed seed crystals are of Mean particle size of less than 2.5 microns.

Techniques for growing crystalline calcium carbonate solids such that the crystalline calcium carbonate solids include a volume of 0.0005 mm³ to 5 mm³, include a slaker to react quicklime (CaO) and a low carbonate content fluid to yield a slurry of primarily slaked lime (Ca(OH)₂); a fluidized-bed reactive crystallizer that encloses a solid bed mass and includes an input for a slurry of primarily slaked lime, an input for an alkaline solution and carbonate, and an output for crystalline calcium carbonate solids that include particles and an alkaline carbonate solution; a dewatering apparatus that includes an input coupled to the crystallizer and an output to discharge a plurality of separate streams that each include a portion of the crystalline calcium carbonate solids and alkaline carbonate solution; and a seed transfer apparatus to deliver seed material into the crystallizer to maintain a consistent mass of seed material.

A method to prepare new or unexpected polymorphs of materials which have not been observed, or to obtain a known polymorph under different conditions than those in which it is usually made, by using a laser to cause nucleation and crystal growth to occur in a supersaturated solution in such a way as to obtain a crystal structure which would not normally appear without the use of the laser.

A process for the production of fullerenes by which a high-purity fullerene can be separated at high productivity from a mixture comprising a fullerene, a polycyclic aromatic hydrocarbon component, and a carbonaceous polymeric component and which comprises the step (A) of preparing a mixture comprising a fullerene, a polycyclic aromatic hydrocarbon component, and a carbonaceous polymeric component, the step (B) of separating this mixture into a polycyclic aromatic hydrocarbon component and a mixture of a fullerene and a carbonaceous polymeric component, and the step (C) of separating this mixture into a fullerene and a carbonaceous polymeric component.

A method for producing high purity D-psicose crystals having a purity of 98% (w/w) or more and a grain size of MA200 or more. The method includes: removing impurities from a D-psicose solution to obtain a purified D-psicose solution; concentrating the purified D-psicose solution; cooling the concentrated D-psicose solution to 30° C. to 40° C. through a heat exchanger; seed crystallizing the D-psicose solution at 30° C. to 40° C. to obtain a seed crystallized massecuite; and full-scale crystallizing the seed crystallized massecuite. The method can produce pure D-psicose crystals in a suitable form for industrial application through an economical crystallization process from the D-psicose solution without using organic solvents.

A method for the extraction and isolation of the terpene and isoprenoid compounds from plant material, followed by a centrifugal force induced selective crystallization of isoprenoids resulting in a separation of terpene and isoprenoid fractions. This this method is suitable for the extraction of cannabinoids from Cannabis and the enrichment tetrahydrocannabinolic acid and reduction of tetrahydrocannabinol in an extract. The purity of tetrahydrocannabinolic acid resulting from centrifugal crystallization is such that dissolution and selective recrystallization of tetrahydrocannabinolic acid is possible resulting in >99.9% pure tetrahydrocannabinolic acid, w/w.

To recycle fluoride by recovering calcium fluoride having a particle size and purity suitable for production of hydrogen fluoride, from a fluoride-containing effluent or a hydrofluoric acid-containing effluent. This method comprises reacting the fluoride-containing effluent or the hydrofluoric acid-containing effluent with an aqueous calcium chloride solution, under an acidic condition with hydrochloric acid where calcium fluoride has a comparatively high solubility. Calcium fluoride having a high purity and a large particle size can be deposited. The hydrochloric acid residues from the reaction or formed through the reaction is reacted with an inexpensive calcium compound such as calcium hydroxide, calcium oxide and calcium carbonate to produce an aqueous calcium chloride solution, and the aqueous calcium chloride solution is reused for the treatment of the hydrofluoric acid-containing effluent. The calcium fluoride obtained can be used as a raw material as it is for producing hydrogen fluoride, and the surplus aqueous calcium chloride solution can be supplied for other industrial uses.

A drop tube type particulate crystalline body producing device is a device for creating a substantially spherical crystalline body by solidifying a particulate melt of an inorganic material while allowing it to free-fall inside a drop tube. This device 1 has a melt formation device 2, drop tube 3, gas flow formation means for forming inside the drop tube 3 a gas flow of cooling gas, and recovery mechanism 5 for recovering a crystalline body 25a from the lower end of the drop tube 3. The drop tube 3 comprises an introducing tube 30, cooling tube 31, and solidification tube 32, where the cooling tube 31 is configured such that the cross sectional area thereof becomes smaller toward the bottom such that the cooling gas flow speed becomes substantially equal to the free fall speed of the particulate melt, and the solidification tube 32 is connected to the lower end of the cooling tube 31 and has a cross sectional area enlarged discontinuously from the lower end of the cooling tube 31. In a proximity of the upper end of the solidification tube 32, the flow speed of the cooling gas is rapidly reduced and the gas pressure increases, whereby a crystal nucleus is generated in the melt in a supercooled state, and the melt is crystallized at once.

The invention introduces a discontinuous crystallization unit for the production of ball-shaped crystals comprising a crystallizer (1) that consists of a metallic cylindrical vessel with its inner surface of a hard material, with an oval or circular cross-section with a conical or vaulted bottom (12), fitted along its length with a duplicator (4) for cooling of the solution and/or suspension of the solution and crystals and a high-speed agitator (8) of a hard material with a drive (9) enabling speed control and thus the rate of the impact of the mechanical action of the agitator on roundness of crystals inside the vessel together with the inner surface of the vessel containing at least 2 baffles (5) of a hard material while the vessel is fitted with at least 1 orifice (10) at the top that at least independent branch of the circulation circuit (11) is connected to from the outside for the inlet of a heated solution and/or heated suspension of the solution and crystals by means of at least 1 circulation pump (2) and through at least 1 heat exchanger (3) and together with the duplicator (4) ensuring controlled periodic changes of temperatures of the crystal suspension around the cooling curve while an interconnection (13) pipeline is connected to the bottom (12) of the crystallizer (1) vessel that is connected to at least one branch of the circulation circuit (11).

The invention relates to a process for manufacturing a particulate titanium dioxide product, wherein hydrated titanium dioxide is precipitated from an aqueous solution of titanium oxychlioride by adding to the solution titanium dioxide particles as crystal nuclei and the product obtained from the precipitation step is isolated and optionally calcined. The process is characterized by the addition of crystal nuclei to an aqueous solution of titanium oxychloride having a content of >90 g TiO₂/l calculated as TiO₂ and the performance of precipitation at a temperature below the boiling point of the said aqueous solution and at normal pressure. In addition, the invention relates to a titanium dioxide product prepared by using the process, the use of the product as a photocatalyst, and a photocatalyst, which comprises a titanium dioxide product prepared according to the invention.