Abstract: The present invention is directed at the synthesis and characterization of recrystallized HI-6 dimethylsulfate (DMS). The method can comprise dissolving HI-6 DMS in an alkyl-based glycol and adding an antisolvent to recrystallize HI-6 DMS or dissolving HI-6 DMS in methanol and adding dimethoxy ethane or dimethyl formamide as the antisolvent to recrystallize HI-6 DMS. The recrystallized HI-6 DMS indicates a resistance to moisture absorption and/or a DSC melting point onset (MP Onset) at least at or above 160.0° C.

Abstract: A potassium hexafluoromanganate (K2MnF6) composition includes no more than six parts per million of each of one or more Group 13 elements, no more than 520 parts per million of one or more alkaline earth metals, no more than fourteen parts per million of one or more transition metals, and/or no more than forty parts per million of calcium. A method for providing this composition, as well as lighting apparatuses, backlight units, and electronic devices including phosphors formed from the composition also are provided.

Abstract: Disclosed herein is a method of producing D-psicose. The method of producing D-psicose includes subjecting D-fructose to D-psicose epimerization to produce a D-psicose-containing solution, subjecting the D-psicose-containing solution to first cooling and ion purification, subjecting the purified D-psicose-containing solution to first concentration and second cooling, subjecting the D-psicose-containing solution, which has been subjected to first concentration and second cooling, to chromatography to obtain a D-fructose-containing mother liquor and a D-psicose-containing separated solution, and subjecting the D-psicose-containing separated solution to second concentration and third cooling to obtain D-psicose crystals, wherein the D-fructose-containing mother liquor produced by chromatography is reused in the D-psicose epimerization.

Abstract: A method for obtaining crystals from a mother solution operates such that mother solution is fed into a crystallisation device. Supersaturation of the mother solution is brought about by open and/or closed-loop control of the temperature (?). Seed crystals are added to the mother solution at a seeding point (Sp). The seed crystals are grown as nuclei by continuous closed-loop process control and are finally removed from the method as crystals. They form the product yield. The formation of crystal nuclei in the mother solution is countered by steps in the closed-loop process control. During the closed-loop process control and the crystallisation procedure, the position of the limit (M) of the formation of secondary nuclei is determined using sensors that detect data currently, wherein the position of the limit (M) is established as a value of the concentration (c) and the temperature (?) from these data.

Abstract: The present invention provides a continuous process for producing ammonium sulfate crystals, wherein said process comprises: i) feeding to a series of crystallization sections, which crystallization sections are heat integrated in series, a solution of ammonium sulfate; ii) crystallizing ammonium sulfate crystals from said solution of ammonium sulfate; iii) purging a fraction of the solution of ammonium sulfate from each of said crystallization sections; and iv) discharging ammonium sulfate crystals from each crystallization section, characterized in that: a fraction of said solution of ammonium sulfate is purged from at least one crystallization section to at least one other crystallization section; and an apparatus suitable for producing ammonium sulfate crystals.

Abstract: The present disclosure provides devices and systems that utilize concurrent and countercurrent exchange platforms to produce purified silicon.

Abstract: A method is provided of shutting down an operating three-phase slurry bubble column reactor (10) having downwardly directed gas distribution nozzles (30) submerged in a slurry body (19) of solid particulate material suspended in a suspension liquid contained inside a reactor vessel (12), with the gas distribution nozzles (30) being in flow communication with a gas feed line (26) through which gas is fed to the gas distribution nozzles (30) by means of which the gas is injected downwardly into the slurry body (19). The method includes abruptly stopping flow of gas from the gas feed line (26) to the gas distribution nozzles (30) to trap gas in the gas distribution nozzles (30) thereby to inhibit slurry ingress upwardly into the gas distribution nozzles (30).

Abstract: Described is a device for inducing crystal nucleation in a crystallizer. The device comprises a vessel for fluid and a surface abrader, wherein the surface abrader is configured to abrade a surface within the vessel to induce crystal nucleation. The friction of the abrader against the surface within the vessel creates nano-sized particulates which induce crystal nucleation. Crystal growth can then take place in the crystallizer. Also described is a crystallization apparatus comprising the device and a crystallization process using the device or similar. The device is significantly cheaper and more reliable than known ultrasound devices and facilitates the separation of crystal nucleation and crystal growth. The device also enables the avoidance of the use of seeding as a source of secondary nucleation.

Abstract: Herein is disclosed a comprehensive mixer performance estimation method that can be applied to the mixers of the rotor-stator type having various configurations and circulation systems. Specifically, the performance estimation method for the mixers of the rotor-stator type includes the steps of: obtaining the homogenization index: H.I. for each of the mixers, measuring the size of each of the mixers, the powder requirements and flow rates during the running time of each of the mixers, estimating the magnitude (smallness or greatness) of the configuration dependent term value of each of the mixer as whole which is specific to each of the mixers, and estimating the performance of each of the mixers accordingly.

Abstract: The present invention relates to an indium oxide film formed by chemical vapor deposition or atomic layer deposition, or to an oxide film containing indium, and to a method for forming same. By chemical vapor deposition or atomic layer deposition, wherein an indium material that is a liquid at room temperature is used, an oxide film containing indium can be formed on a substrate having a large area, and particularly a substrate for manufacturing a display device.

Abstract: Embodiments of an obstructing member and methods for its use in a fluidized bed reactor are disclosed. The obstructing member comprises a plurality of receiving members, each receiving member comprising a tubular wall defining a passageway dimensioned to receive an internal reactor component, and a plurality of connecting elements connecting the receiving members, wherein the obstructing member occupies from 15-60% of a horizontal cross-section of a reaction chamber of the fluidized bed reactor.

Abstract: A method of making a micro-wire rib structure includes providing a substrate and locating a curable layer on or over the substrate. The curable layer is imprinted and cured to form a cured layer including a cured-layer surface and a micro-channel having a micro-channel depth, a micro-channel bottom, first and second micro-channel sides, and one or more ribs having opposing rib sides and a rib top defining a rib height less than the micro-channel depth. Each rib is located between the first and second micro-channel sides and extends from the micro-channel bottom toward the cured-layer surface. A curable conductive material is located in the micro-channel and cured to provide a cured electrical conductor forming a micro-wire in the micro-channel.

Abstract: An arrangement and a method for producing high-purity crystals, such as temperature-sensitive pharmaceutical agents, in a countercurrent crystallization process. The arrangement comprises a plurality of crystallizers, mother liquor lines, each of which has a shut-off valve, and crystallization product lines, each of which has a shut-off valve, so that a mother liquor flow can be generated which is directed from a crystallizer to the second-next crystallizer in the direction of decreasing purity, and a crystallization product flow can be generated which is directed from a to dissolved crystallization product that is about to crystallize to the next crystallizer in the direction of higher purity.

Abstract: The present invention provides a method for producing metal-supported carbon, which includes supporting metal microparticles on the surface of carbon black, by a liquid-phase reduction method, in a thin film fluid formed between processing surfaces arranged to be opposite to each other so as to be able to approach to and separate from each other, at least one of which rotates relative to the other, as well as a method for producing crystals comprising fullerene molecules and fullerene nanowhisker/nanofiber nanotubes, which includes uniformly stirring and mixing a solution containing a first solvent having fullerene dissolved therein, and a second solvent in which fullerene is less soluble than in the first solvent, in a thin film fluid formed between processing surfaces arranged to be opposite to each other so as to be able to approach to and separate from each other, at least one of which rotates relative to the other.

Abstract: A graphite crucible for silicon single crystal manufacturing by the Czochralski method, having a long life cycle, contains at least one gas venting hole provided in a corner portion of the crucible. Gas generated by reaction between the graphite crucible and a quartz crucible is released to the outside through the gas venting hole, and formation of SiC on the surface of the graphite crucible and deformation of the quartz crucible caused by the pressure of the generated gas are prevented.

Abstract: A potash-extraction system and method for extracting potash from a brine containing potash without the use of water-consuming evaporation ponds or additional chemicals is disclosed. The potash processing system uses a mechanical-vapor recompression (“MVR”) cycle to separate salt and then potash from a sylvinite brine containing salt and potash. In embodiments, the latent heat recovered from condensing vapor may be used to boil the brine to precipitate some salt and remove some water (in the form of water vapor) from the brine. The remaining potash-concentrated brine may then be cooled to precipitate potash from the solution. The precipitated potash may then be further processed for final use.

Abstract: The present invention relates to single walled and multi-walled carbon nanotubes (CNTs), functionalized CNTs and carbon nanotube composites with controlled properties, to a method for aerosol synthesis of single walled and multi-walled carbon nanotubes, functionalized CNTs and carbon nanotube composites with controlled properties from pre-made catalyst particles and a carbon source in the presence of reagents and additives, to functional, matrix and composite materials composed thereof and structures and devices fabricated from the same in continuous or batch CNT reactors. The present invention allows all or part of the processes of synthesis of CNTs, their purification, doping, functionalization, coating, mixing and deposition to be combined in one continuous procedure and in which the catalyst synthesis, the CNT synthesis, and their functionalization, doping, coating, mixing and deposition can be separately controlled.

Abstract: Systems and a method for forming carbon nanotubes are described. A method includes forming carbon nanotubes in a reactor, using a Bosch reaction. The carbon nanotubes are separated from a reactor effluent to form a waste gas stream. The feed gas, a dry waste gas stream, or both, are heated with waste heat from the waste gas stream. The waste gas stream is chilled in an ambient temperature heat exchanger to condense water vapor, forming a dry waste gas stream.

Abstract: Method and apparatus are presented for synthesis SWNT (single wall) or MWNT (multiple walls) of the carbon nanotube structure. According to the invention the very long length of the carbon tube can be synthesized in the spiral threaded holes of the rotating cylinders using the electromagnetic resonance phenomena.

Abstract: A method is described for the manufacture of semiconductor nanoparticles. Improved yields are obtained by use of a reducing agent or oxygen reaction promoter.

Abstract: The invention in some aspects relates to devices and methods for nucleating crystals under controlled conditions. In some aspects of the invention, devices and methods are provided for continuous crystallization.

Abstract: A multi-ingot furnace for the growth of crystalline semiconductor material has one or more heating devices for heating a hot zone in which crucibles containing semiconductor material are received. At least one of the heating devices is arranged to apply a predetermined differential heat flux profile across a horizontal cross-section of the semiconductor material in one or more of the crucibles, the predetermined differential heat flux profile being selected in dependence the position of the one or more crucibles in an array. In this manner, the heating device can at least partially compensate for differences in the temperature across the semiconductor material that arises from its geometric position in the furnace. This reduces the possibility of defects such as dislocations during the growth of a crystalline semiconductor material. Associated methods are also disclosed.

Abstract: A high temperature furnace comprising hot zone insulation having at least one shaped thermocouple assembly port to reduce temperature measurement variability is disclosed. The shaped thermocouple assembly port has an opening in the insulation facing the hot zone that is larger than the opening on the furnace shell side of the insulation. A method for producing a crystalline ingot in a high temperature furnace utilizing insulation having a shaped thermocouple assembly port is also disclosed.

Abstract: 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.

Abstract: A reaction-crystallization apparatus for carrying out reaction and/or solvent extraction and/or crystallization of soluble salts has an upper section having a top and a decanter. The decanter has a vertical vessel having a horizontal weir at the top of the upper section. The top of the upper section has an outlet for removing a light phase at the top of the decanter. The apparatus has a lower section, including a crystallizer. The crystallizer includes: a coaxial draft tube; a feed pipe; an agitator inside the draft tube; and at least one outlet at the bottom for crystal slurry removal. The apparatus has an intermediate section sandwiched between the lower section and the upper section such that the sections are in fluid communication and includes at least one coaxial vertical baffle with a gap between the draft tube and the coaxial vertical baffle and is adjustable by moving the baffle.

Abstract: Reactor designs for use in ammonothermal growth of group-III nitride crystals. Internal heating is used to enhance and/or engineer fluid motion, gas mixing, and the ability to create solubility gradients within a vessel used for the ammonothermal growth of group-III nitride crystals. Novel baffle designs are used for control and improvement of continuous fluid motion within a vessel used for the ammonothermal growth of group-III nitride crystals.

Abstract: A method for the evaporative production of phenol-BPA adduct crystals in a crystallizer is provided. First, a supersaturated BPA solution is introduced into a crystallizer that includes a cylindrical vessel and a concentrically-disposed draft tube that defines an annular space between the vessel and tube. Next, the BPA solution is circulated through the draft tube and annular space while a coolant is uniformly distributed in the circulating flow by radially injecting a volatile hydrocarbon compound at between about 30% and 60% of a radial extent of the annular space of to form a BPA mixture. Phenol-BPA adduct crystals are produced in the vessel by evaporating the volatile hydrocarbon compound out of the BPA mixture. The method provides a consistent and uniform concentration of coolant across the surface of the boiling zone that prevents or at least reduces unwanted crystal nucleation.

Abstract: A production saltwater disposal facility comprising a separator configured to receive production saltwater from a pipeline or a vehicle and separate hydrocarbons from the production saltwater, wherein the production saltwater received from the pipeline or vehicle is substantially the same composition as when the production saltwater was located in a subterranean formation, a hydrocarbon storage tank configured to receive hydrocarbons from the separator, a settling pit configured to receive the production saltwater from the separator and separate metals and/or other solids from the saltwater, an evaporator in fluid communication with the settling pit and comprising a nozzle configured to emit a stream of the saltwater along a path in air such that water in the saltwater evaporates, and a collection pit positioned under the path and configured to collect the salt from the saltwater after the water has evaporated.

Abstract: 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.

Abstract: A nanovolume microcapillary crystallization system allows nanoliter-volume screening of crystallization conditions in a crystal card that allows crystals to either be removed for traditional cryoprotection or in situ X-ray diffraction studies on protein crystals that grow within. The system integrates formulation of crystallization cocktails with preparation of the crystallization experiments. The system allows the researcher to select either gradient screening in crystallization experiments for efficient exploration of crystallization phase space or a combination of sparse matrix with gradient screening to execute one comprehensive hybrid crystallization trial.

Abstract: The present invention relates to a reaction vessel for crystallization of a sample from a solution and a covering foil and an arrangement for mounting the covering foil.

Abstract: Method for the production of a coarse-grained ammonium sulphate product by crystallization and installation for carrying out the method from an ammonium sulphate solution in a DTB type crystallizer having an internal suspension circuit and a clarifying zone, from which a clarified partial flow of solution is constantly drawn off into an external circuit, is heated in a heat exchanger to dissolve the solids contained therein and is guided back as a clear solution into the lower region of the crystallizer. A fine crystal suspension flow is drawn off from the clarifying zone as a further partial flow and guided back into the internal circuit of the crystallization stage without any previous dissolution of the solid proportion contained therein.

Abstract: A set of crystallization solutions includes a plurality of crystallization solutions of Crystallization Solution Set I, a plurality of crystallization solutions of Crystallization Solution Set II or a plurality of crystallization solutions of Crystallization Solution Set III.

Abstract: Reactor designs for use in ammonothermal growth of group-III nitride crystals. Internal heating is used to enhance and/or engineer fluid motion, gas mixing, and the ability to create solubility gradients within a vessel used for the ammonothermal growth of group-III nitride crystals. Novel baffle designs are used for control and improvement of continuous fluid motion within a vessel used for the ammonothermal growth of group-III nitride crystals.

Abstract: Disclosed are systems and methods for processing carnallite or sylvinite ores. The system includes a measuring hopper, a lye clarifier, two vertical ore dissolving apparatuses, two ore dehydrators and one wet product dehydrator, a crystallizer, and a dryer. Each dissolving apparatus has alternating supply and grounding electrodes arranged in axial alignment with the apparatus. The ore is run through both dissolving apparatuses in succession and dehydrated after each dissolving apparatus. A dissolving lye is fed to each dissolving apparatus in countercurrent flow to the solid phase ore. The saturated lye from the dissolving apparatuses is transported to a crystallizer to be cooled. Cooling the lye forms crystalline potassium chloride or artificial carnallite, which then goes for dehydration and drying.

Abstract: The present invention relates to means and methods for producing crystals or crystalline substances. In particular, crystals or crystalline substances which are useful as pharmaceutical ingredients can be manufactured.

Abstract: Embodiments of the inventive concept provide a successive gas hydrate manufacturing device, without hydration after generating gas hydrate slurry, capable of operating with a higher conversion rate and relatively low hydrate generation pressure and reducing a product cost by decreasing the number of processing steps for removing heat of reaction, for which the total exothermic value downs due to no need of latent heat according to a phase change rather than the case of generating a gas hydrate directly from a water solution, as well as making gas diffusion easier during reaction of generation and maximizing a contact area between water and gas to increase a gas capture rate and shorten the total hydrate generation time.

Abstract: A process to produce a dry purified furan-2,5-dicarboxylic acid (FDCA) is described. After oxidation of 5-(hydroxymethyl)furfural (5-HMF), a crude FDCA stream is produced that is fed to a crystallization zone followed by a solid-liquid displacement zone to form a low impurity slurry stream. The solids in the low impurity slurry stream are dissolved in a dissolution zone to produce a hydrogenation feed that is hydrogenated in a hydrogenation reactor to generate a hydrogenated FDCA composition. The hydrogenated FDCA composition is routed to a crystallization zone to form a crystallized produce stream that is separated from liquid in a solid-liquid separation zone to generate a purified wet cake stream containing FDCA that can be dried in a drying zone to generate a dry purified FDCA product stream.

Abstract: To provide a production method for a nitride crystal, where a nitride crystal can be prevented from precipitating in a portion other than on a seed crystal and the production efficiency of a gallium nitride single crystal grown on the seed crystal can be enhanced. In a method for producing a nitride crystal by an ammonothermal method in a vessel containing a mineralizer-containing solution, out of the surfaces of said vessel and a member provided in said vessel, at least a part of the portion coming into contact with said solution is constituted by a metal or alloy containing one or more atoms selected from the group consisting of tantalum (Ta), tungsten (W) and titanium (Ti), and has a surface roughness (Ra) of less than 1.80 ?m.

Abstract: The method and apparatus includes a vessel having a bottom and sidewalls arranged to house the material in a molten state. A temperature controlled horizontally oriented, cooling plate is movable into and out of the top of the molten material. When the cooling plate is lowered into the top of the melt, an ingot of solid silicon is solidified downwards.

Abstract: Boron-containing compounds, gasses and fluids are used during ammonothermal growth of group-Ill nitride crystals. Boron-containing compounds are used as impurity getters during the ammonothermal growth of group-Ill nitride crystals. In addition, a boron-containing gas and/or supercritical fluid is used for enhanced solubility of group-Ill nitride into said fluid.

Abstract: Processes and apparatus for purifying brine are provided including (1) providing an aqueous brine solution comprising one or more inorganic salts and one or more organic compounds and (2) conducting at least one unit operation for removing organic compounds from the brine solution to obtain a purified brine solution.

Abstract: The invention relates to a method for the continuous production of semicrystalline polycondensate pellets. Said method comprises the following steps: producing a polycondensate material; shaping polycondensate pellets and solidifying the polycondensate melt in a liquid cooling medium, wherein the shaping of the pellets can be carried out prior to or after solidification; separating the pellets from the liquid cooling medium once the polycondensate pellets have cooled down to an average temperature that lies within the crystallization temperature range of the polycondensate; and crystallizing the pellets in a treatment chamber, the treatment gas being led in said treatment chamber in a countercurrent to the polycondensate pellets, the flow rate of the treatment gas being above the incipient fluidization point of the polycondensate pellets and the polycondensate pellets having a narrow dwell time spectrum in the treatment chamber.

Abstract: A method for preparing contaminated plastics ground into flakes, such as RPET or such polymers, having at least decontamination and SSP treatment steps, with at least one reactor, with heating to the process temperature taking place essentially outside the reactor. Also, a device for carrying out the method, and having at least one decontamination reactor and at least one SSP reactor, a device for heating plastic flakes to the process temperature being arranged upstream of the decontamination reactor. Also an SSP reactor having at least two individual reactors, and preferably between 3 and 7 individual reactors.

Abstract: Methods of forming potassium sulfate include calcining polyhalite ore particles to convert the polyhalite ore particles to a water-soluble composition. At least a portion of the water-soluble composition is dissolved in an aqueous medium to form an aqueous solution comprising K+, Mg2+, and SO42? ions and a calcium-containing solid. The calcium-containing solid is separated from the aqueous solution to form a filtrate comprising K+, Mg2+, and SO42? ions. A potassium-containing salt is dissolved in the filtrate to increase the concentration of K+ and SO42? ions to from a concentrated liquor, and K2SO4 is crystallized from the concentrated liquor. A system for processing polyhalite ore includes a countercurrent leaching apparatus, a first mix tank, an evaporator, and at least one crystallizer.

Abstract: Provided are a method for preparing fine round powdery polycarbonate and a method for preparing a high molecular weight polycarbonate resin using the same. More specifically, provided are a method for preparing fine round powdery polycarbonate, comprising (A) polymerizing non-phosgene polycarbonate, (B) extruding the polycarbonate into fine round powdery amorphous polycarbonate, (C) surface-crystallizing the fine round powdery amorphous polycarbonate in the presence of a solvent or dispersion medium, and (D) drying the surface-crystallized fine round powdery polycarbonate, and a method for preparing high molecular weight polycarbonate resin capable of obtaining polycarbonates with various molecular weights ranging from low molecular weights to high molecular weights by continuously using the obtained fine round powdery polycarbonate via a solid state polymerization step.

Abstract: The present invention relates to a crucible that can be used for solidifying a silicon ingot from molten silicon, characterized in that same is at least partially coated on the inner surface thereof with at least one layer consisting of a material produced by thermal decomposition of polysilizane(s), said layer having a shear strength greater than 1 Pa and no higher than 500 MPa, and being in the form of a stack of adjoining layers of non-contiguous tiles. The invention also relates to a method for preparing such crucibles.

Abstract: Method for the production of a coarse-grained ammonium sulphate product by crystallization and installation for carrying out the method. A method for the continuous production of a coarse-grained ammonium sulphate product from an ammonium sulphate solution in a crystallizer operates in accordance with the DTB principle and has an internal suspension circuit and a clarifying zone, from which a clarified partial flow of solution is constantly drawn off into an external circuit, is heated in a heat exchanger so as to dissolve the solids contained therein and is then guided back as a clear solution into the lower region of the crystallizer. In order to ensure production of a product crystallizate with a grain coarseness which is practically constant over time, a fine crystal suspension flow may be drawn off from the clarifying zone as a further partial flow and guided back into the internal circuit of the crystallization stage without any previous dissolution of the solid proportion contained therein.

Abstract: The invention proposes a method and a device for continuously producing a crystallite, wherein a metered amount of seed crystals is fed continuously to the internal solution circuit of a crystallizer, in particular a DTB crystallizer, through a crystallization seed line from a seed generator preferably designed as a flash crystallizer. The amount of seed crystals fed is controlled by an electronic control system as a function of a measured value determined by a sensor, said value being representative of the particle size distribution of the crystallites in the solution in the internal circuit in the crystallizer. By way of a line, the seed generator receives a partial stream of the external solution circuit of the crystallizer, said external circuit being routed through a line. Excess fine crystalline suspension can be fed back to the external circuit from the seed generator by way of a return line.

Abstract: A process is provided for preparing a salt product with reduced sodium content including the step of providing a concentrated brine, which is typically seawater, to which has been added potassium chloride. The mixture is transferred to a crystalliser unit where at least a portion of the mix is transferred to the crystalliser through a washing column. Liquid is evaporated from the crystalliser such that crystals form, crystals are passed from the crystalliser through said washing column to a separating unit such that in the passing through the washing column the crystals are rinsed with the brine portion being transferred as a counter current through the column. The inventive process is characterised by recycling of the brine from which the salt crystallises, thus all main ingredients of the mixed input brine reach a steady equilibrium concentration in the mother liquor in the crystalliser.