Abstract: A process for preparing synthetic calcium fluoride (CaF2) (min 90% CaF2 by weight) from fluosilicic acid is provided. The processes comprises the steps of (a) reacting fluosilicic acid (H2SiF6) with ammonium hydroxide or ammonia in a first reactor so as to obtain a first slurry and filtering the first slurry so as to obtain a filtrate containing a solution of ammonium fluoride (b) precipitating the solution of ammonium fluoride with calcium in a second reactor so as to produce a second slurry containing calcium fluoride and (c) evolving the major part of ammonia from the second reactor and then scrubbing and returning said ammonia to the first reactor.

Abstract: The present invention relates to a high purity synthetic fluorite (CaF2). The present invention further relates to a process and an apparatus for preparing said high purity synthetic fluorite (CaF2), classified as acid grade, starting from fluorosilicic acid H2SiF6 (FSA) and calcium carbonate (CaCO3). Finally, the present invention relates to the use of said high purity synthetic fluorite (CaF2) in the industrial production of hydrofluoric acid.

Abstract: A CaF2 polycrystalline body which is a polycrystalline body constituted of CaF2 and of which an average grain size of crystalline grains is 200 ?m or more, and a method for producing a CaF2 polycrystalline body, the method including a process of introducing a compact which is obtained by using a CaF2 powder raw material into a vacuum sintering furnace and sintering at a temperature of not higher than 1400° C. for six hours or more, thereby obtaining the CaF2 polycrystalline body.

Abstract: A crystal growth device includes a crucible and a heater setting. The crucible has a bottom and a top opening. The heater setting surrounds the crucible and is movable relative to the crucible along a top-bottom direction of the crucible and between first and second positions. The heater setting includes a first temperature heating zone and a second temperature heating zone higher in temperature than the first temperature heating zone. The heater setting is in the first position when the crucible is in the second temperature heating zone and in the second position when the crucible is in the first temperature heating zone.

Abstract: The present invention relates to a process for preparing high-purity lithium fluoride proceeding from lithium carbonate, and to lithium fluoride having a preferred morphology.

Abstract: Magnesium fluoride particles with a low refractive index excellent in film formability are provided. The magnesium fluoride particles each include at least one magnesium fluoride particulate. The at least one magnesium fluoride particulate each has pores that support a supported substance. Further, the at least one magnesium fluoride particulate includes a plurality of particulates. A grain boundary void-like pore serving as a gap that supports the supported substance is present between particulates adjacent to each other of the plurality of particulates.

Abstract: The disclosure provides low-molecular-ratio cryolite for aluminum electrolytic industry, which consists of potassium cryolite and sodium cryolite with a mole ratio of 1:1˜1:3, wherein the molecular formula of the potassium cryolite is mKF.AlF3 and the molecular formula of the sodium cryolite is nNaF.AlF3, where m=1˜1.5 and n=1˜1.5. When the low-molecular-ratio cryolite provided by the disclosure is applied to the aluminum electrolytic industry, electrolytic temperature and power consumption can be reduced and electrolytic efficiency is improved.

Abstract: The present invention relates to a hydrogen-storing composite material which is convertible essentially reversibly between a storing state and a non-storing state, wherein the reaction enthalpy in this conversion reaction can be set in a targeted manner to a value between 15 and 80 kJ/mol of H2, preferably 25 to 40 kJ/mol of H2.

Abstract: According to one embodiment, a fluorine recovering apparatus includes a precipitating device allowing fluoride ion-containing water to react with calcium source to form precipitate, a mixing tank mixing a filter aid including particles of a magnetic material having a diameter of 0.5 to 5 ?m with a dispersion medium to produce slurry, a filter aid feeder to the mixing tank, a solid-liquid separator with a filter depositing a filter aid layer, and depositing the precipitate on the filter aid layer, a cleaning mechanism removing the filter aid and the precipitate, a separating tank separating the filter aid and the precipitate, and a returning mechanism returning the filter aid to the filter aid feeder.

Abstract: A method of reacting amine compounds with halons and perhalogenated compounds, resulting in the conversion of these ozone-depleting species into non-volatile salts and a variety of other amine derivatives is disclosed.

Abstract: The invention is directed to a process of combining an aqueous solution of a fluoride with an aqueous solution of a host multi-valent metal salt and an aqueous solution of a salt forming a reactant mixture resulting in a precipitate of aqueously insoluble rare-earth doped multi-valent metal fluoride nanoparticles.

Abstract: A fluorite having all the more excellent laser durability compared to a conventional fluorite is provided. A fluorite is proposed, in which the standard deviation of the surface areas of the Voronoi regions in a diagram from a Voronoi segmentation of the distribution of etch-pits in the (111) plane is 6,000 ?m2 or less, or, in which the standard deviation of the distances of the Delaunay edges in a diagram from a Delaunay segmentation of the distribution of etch-pits of the (111) plane is 80 ?m or less.

Abstract: Disclosed are compositions and methods for reducing dentin hypersensitivity. Also disclosed are compositions containing calcium fluoride nanoparticles.

Abstract: A method for processing fluoride-containing wastewaters from a factory, which includes the following steps: Step 1: collecting the fluoride-containing wastewaters into three pools: an acidic high-fluoride wastewater, an acidic low-fluoride wastewater, and an alkaline wastewater; Step 2: adding a calcium compound to the acidic low-fluoride wastewater to produce a calcium-containing solution; Step 3: reacting a portion of the calcium-containing solution with the acidic high-fluoride wastewater at a calcium-to-fluoride molar ratio of from about 0.5:1 to about 1.

Abstract: The present invention relates generally to production of a fluoride gas and equivalents thereof, and fluorine-doped sodium silicate glass, glass ceramics, vitro ceramics and equivalents thereof. In one embodiment, the method includes providing a salt and an oxide in a reactor, heating the reactor to produce a vapor and the vitro ceramic and removing the vapor.

Abstract: The disclosure provides an electrolyte supplement system in an aluminum electrolysis process, which includes low-molecular-ratio cryolite, wherein the low-molecular-ratio cryolite is selected from mKF.AlF3, nNaF.AlF3 or mixture thereof, where m=1˜1.5 and n=1˜1.5. When the electrolyte supplement system provided by the disclosure is applied to the aluminum electrolytic industry, electrolytic temperature can be reduced obviously in the aluminum electrolysis process without changing the existing electrolytic process; thus, power consumption is reduced, volatilization loss of fluoride is reduced and the comprehensive cost of production is reduced.

Abstract: A CaF2 polycrystalline body which is a polycrystalline body constituted of CaF2 and of which an average grain size of crystalline grains is 200 ?m or more, and a method for producing a CaF2 polycrystalline body, the method including a process of introducing a compact which is obtained by using a CaF2 powder raw material into a vacuum sintering furnace and sintering at a temperature of not higher than 1400° C. for six hours or more, thereby obtaining the CaF2 polycrystalline body.

Abstract: The invention generally relates to methods of selectively removing lithium from various liquids, methods of producing high purity lithium carbonate, methods of producing high purity lithium hydroxide, and methods of regenerating resin.

Abstract: A Ca—La—F based transparent ceramic, including: mixing CaF2 particles and LaF3 particles that are prepared separately from the CaF2 particles to form a mixed body of particles, and sintering the mixed body of particles and making the mixed body transparent, thereby producing a transparent ceramic.

Abstract: A method for preparing uniquely sized nanoparticles of CaF2 by simultaneously spray drying a first NH4F and a biocompatible salt solution and a second Ca(OH)2 and biocompatible salt solution to form CaF2 solid particles in a soluble salt matrix wherein the salt is more soluble than CaF2. The salt matrix may then be dissolved and the separate CaF2 nanosized particles collected for use as a dental therapeutic material. The technique is useful in the preparation of other discrete, nanoparticle sized compounds and combinations by carefully choosing the solvents and solutes of the two spray dried solutions.

Abstract: A hair care composition containing inorganic fluoride for straightening, smoothing, and/or relaxing hair, and a method for using the hair care composition a hair care composition containing an inorganic fluoride for straightening, smoothing, defrizzing, curling and/or relaxing of hair, and its method of use in a variety of hair care products, e.g., straightener solution, shampoo, conditioner, color binding treatment, volumizing treatment, a combination thereof, etc. The hair care composition is formaldehyde-free, even when heated.

Abstract: Antiseptic compounds that act as persistent and fast acting antiseptics and disinfectants. The base of these antiseptic actions is CaF2 as the persistent part, preventing the colonization of tissue and nonliving surfaces with microorganisms through the targeted on-demand release of fluorine ions. For fighting heavy contamination and invasion of transient microbes through new application of the solution, fast acting alcohols and toxic solutions have been added in small percentage. They act fast and evaporate fast, leaving the natural protection of skin undamaged and coated with a persistent antiseptic.

Abstract: A transmissive optical device includes a crystal part including a c-axis in a crystal structure. The crystal part is configured to include a surface to receive a laser beam. The c-axis is arranged to be inclined relative to an incident direction of the laser beam in a plane of incidence of the laser beam.

Abstract: The present invention provides a method of producing hollow magnesium fluoride particles by performing polymerization at the interface of micelle constituted of a hydrophobic solvent, a hydrophilic solvent, and a surfactant. The invention further provides an antireflection coating having a low refractive index due to the coating by the hollow magnesium fluoride particles and also provides an optical device coated with the antireflection coating and an imaging optical system having the optical device. In the method, micelle is formed from a hydrophobic solvent, a hydrophilic solvent, and a surfactant, and then a fluorine compound and a magnesium compound are dissolved in the micelle solution to polymerize magnesium fluoride at the interface of the micelle.

Abstract: A fluorite with excellent laser durability is provided by devising a heat-treatment method for CaF2 crystal. A fluorite production method is proposed, wherein heat-treatment is carried out by providing, through compartment walls in the periphery of a fluorite crystal, a fluoride gas trap layer containing a fluoride gas-adsorbing material.

Abstract: The described invention provides compositions related to an electronically insulating amorphous or nanocrystalline mixed ionic conductor composition comprising a metal fluoride composite to which an electrical potential is applied to form 1) a negative electrode, and 2) a positive electrode, wherein the negative electrode and positive electrode are formed in situ.

Abstract: According to one embodiment, a fluorine recovering apparatus includes a precipitating device allowing fluoride ion-containing water to react with calcium source to form precipitate, a mixing tank mixing a filter aid including particles of a magnetic material having a diameter of 0.5 to 5 ?m with a dispersion medium to produce slurry, a filter aid feeder to the mixing tank, a solid-liquid separator with a filter depositing a filter aid layer, and depositing the precipitate on the filter aid layer, a cleaning mechanism removing the filter aid and the precipitate, a separating tank separating the filter aid and the precipitate, and a returning mechanism returning the filter aid to the filter aid feeder.

Abstract: The present invention relates to a fluorine-containing magnesium oxide powder using a vapor phase reaction and a method of preparing the same and more particularly to a fluorine-containing magnesium oxide powder brings about a cathode-luminescence emission having a peak within a wavelength range of 220 to 320 nm upon being excited by electron beams. The present invention provides a fluorine-containing magnesium oxide powder using a vapor phase reaction that sprays fluorine-containing gas and oxygen-containing gas to magnesium vapor, and the purity of magnesium oxide containing fluorine (i.e. the purity of fluorine-containing magnesium oxide) of 0.001 to 2 wt % is at least 98 wt % and a BET specific surface area thereof is 0.1 to 50 m2/g.

Abstract: A process for producing fluoride crystals, in particular calcium fluoride crystals, having high radiation resistance to ultraviolet radiation, which includes: provisioning of a crystal powder (6) containing alkali metal fluoride or alkaline earth metal fluoride to form a raw crystal mass, melting of the raw crystal mass in a crystal growing unit (11) and solidifiying of the molten raw crystal mass by cooling. In the process, an ammonium salt (7) of a complex fluoro acid and an aliphatic alcohol (8) are added to the crystal powder (6) or to the raw crystal mass, to decrease oxidic impurities. A fluoride crystal produced by the process and also an optical component formed from such a fluoride crystal are also disclosed.

Abstract: A method of producing a Ca—La—F based transparent ceramic, including: mixing CaF2 particles and LaF3 particles that are prepared separately from the CaF2 particles to form a mixed body of particles, and sintering the mixed body of particles and making the mixed body transparent, thereby producing a transparent ceramic.

Abstract: The invention generally relates to methods of selectively removing lithium from various liquids, methods of producing high purity lithium carbonate, methods of producing high purity lithium hydroxide, and methods of regenerating resin.

Abstract: The invention generally relates to methods of selectively removing lithium from various liquids, methods of producing high purity lithium carbonate, methods of producing high purity lithium hydroxide, and methods of regenerating resin.

Abstract: The object of the present invention is a new inkjet printable etching composition comprising an etchant, which is activated by a second component. Thus, a further object is the use of this new composition in a process for the etching of surfaces semiconductor devices or surfaces of solar cell devices.

Abstract: A single crystal of magnesium fluoride having a large diameter and excellent optical properties such as internal transmittance and long term laser durability, and suited for use as optical elements for exposing apparatus. The single crystal of magnesium fluoride is of a cylindrical shape having a straight body portion of a diameter of not smaller than 10 cm, has an internal transmittance of at least 85%/cm at 120 nm and at least 98%/cm at 193 nm and has, desirably, an induced absorption of not larger than 0.0030 absorption/cm at 255 nm and, particularly desirably, not larger than 0.0010 absorption/cm. at 255 nm immediately after the irradiation with 2 million shorts of an ArF excimer laser of an energy density of 30 mJ/cm2 and 2000 Hz. The invention further provides an optical element for optical lithography comprising the single crystal and an optical member for vacuum ultraviolet ray transmission comprising the single crystal.

Abstract: High energy reaction of halogen-containing carbon, boron, silicon and nitrogen compounds, with base component comprising at least one atom selected from Groups IA to VIA, transition metals, lanthanides and actinides of the Periodic Table of the Elements, excluding aluminum and aluminum oxide.

Abstract: In one embodiment, the present disclosure relates generally to a method for thermally decomposing a complex precursor salt. In one embodiment, the method includes heating a salt in a reactor until a molten salt is formed, adding the complex precursor salt to the molten salt in the reactor and removing a volatile precursor halide formed from thermal decomposition of the complex precursor salt from the reactor.

Abstract: An object of the invention is to provide a process for preparing a fluorine compound, which can easily give the objective fluorine compound using an oxygen-containing compound as a raw material without forming water as impurities as a by-product. The process for preparing a fluorine compound according to the invention includes reacting an oxygen-containing compound, which is at least one kind selected from the group consisting of oxides, hydroxides, hydrates, carbonic acid compounds, hydrogencarbonic acid compounds, boric acid compounds, sulfuric acid compounds, sulfurous acid compounds, phosphorous acid compounds and phosphoric acid compounds of at least any one kind selected from the group consisting of metal elements, H, B, C, N, Si, P, S, As, Se, Te and halogens, at least with carbonyl fluoride to form at least a fluorine compound and carbon dioxide without forming water as a by-product.

Abstract: An object (first object) of the invention is to provide a waste water treatment technology (pretreatment technology in particular) which makes it possible to recover fluorine at a high recovery rate as highly pure calcium fluoride, without diluting waste water containing fluorine and silicon, i.e. to recover fluorine from high-concentration waste water containing fluorine and silicon. Waste water containing fluorine and silicon is supplied to a pH controlling tank 1 and sodium hydroxide (NaOH) is added thereto, with the result that sodium silicate is precipitated. Thereafter, the waste water is supplied to a solid-liquid separator 2 so that solid-liquid separation of sodium silicate is conducted.

Abstract: The invention generally relates to methods of selectively removing lithium from various liquids, methods of producing high purity lithium carbonate, methods of producing high purity lithium hydroxide, and methods of regenerating resin.

Abstract: There is provided a sintered body that does not readily deform during use and that allows a high flexibility for the design of surface layers, a method for manufacturing the sintered body, and an optical component including the sintered body. The method for manufacturing a sintered body includes a sintered body having a predetermined shape, the sintered body having a ceramic base material, the method for manufacturing a sintered body comprising a step for preparing a ceramic preform, a step for using a predetermined mold having an upper die and a lower die to hot-press the ceramic preform to form a pressure-sintered body, and a step for cooling the pressure-sintered body while applying a pressure load of approximately 5% or more and 100% or less (and preferably approximately 20% or more and 40% or less) of the pressure load applied during the step for forming the pressure-sintered body.

Abstract: The method produces low-stress, large-volume crystals with low birefringence and uniform index of refraction. The method includes growing the crystal with larger than desired dimensions including diameter and height from a melt; cooling and tempering the crystal with the larger than desired dimensions and after the cooling and tempering removing edge regions of the crystal with the larger than desired dimensions so that a diameter reduction and a height reduction of at least five percent occurs respectively and so that the crystal has the desired dimensions of diameter and height. No further tempering takes place after removing of the edge regions.

Abstract: To provide a method and apparatus for treating a waste gas containing fluorine-containing compounds, according to which PFCs can be decomposed efficiently even at low temperature, and moreover fluorine from the product of the decomposition can be recovered for reuse efficiently. An embodiment of the present invention relates to a method of treating a gas containing a fluorine-containing compound, comprising contacting the gas with a treatment agent comprising a mixture of aluminum hydroxide and calcium hydroxide.

Abstract: Based on designs concerning boron nitride thin-films each including boron nitride crystals in acute-ended shapes excellent in field electron emission properties, and designs of emitters adopting such thin-films, it is aimed at appropriately controlling a distribution state of such crystals to thereby provide an emitter having an excellent efficiency and thus requiring only a lower threshold electric field for electron emission. In a design of a boron nitride thin-film emitter comprising crystals that are each represented by a general formula BN, that each include sp3 bonded boron nitride, sp2 bonded boron nitride, or a mixture thereof, and that each exhibit an acute-ended shape excellent in field electron emission property; there is controlled an angle of a substrate relative to a reaction gas flow upon deposition of the emitter from a vapor phase, thereby controlling a distribution state of the crystals over a surface of the thin-film.

Abstract: Antiseptic compounds that act as persistent and fast acting antiseptics and disinfectants. The base of these antiseptic actions is CaF2 as the persistent part, preventing the colonization of tissue and nonliving surfaces with microorganisms through the targeted on-demand release of fluorine ions. For fighting heavy contamination and invasion of transient microbes through new application of the solution, fast acting alcohols and toxic solutions have been added in small percentage. They act fast and evaporate fast, leaving the natural protection of skin undamaged and coated with a persistent antiseptic.

Abstract: For a continuous process for preparing rare-earth doped Group 2 or Group 3 metal fluoride nanoparticles comprising a confluence of feed streams of reagents, a method is provided for controlling particle size by adjustment in the flow rate of the streams.

Abstract: A ceramic having at least about 90% by weight magnesium aluminate and having a bulk scattering and absorption loss of less than about 1/cm at any wavelength in a range of about 0.23 to about 5.3 microns or 0.2/cm at any wavelength in a range of about 0.27 to about 4.5 microns. A method of making a ceramic by providing a plurality of particles having a magnesium aluminate core and a fluoride salt coating; heating the particles in an oxidizing atmosphere to a temperature in the range of about 400° C. to about 750° C.; and sintering the particles to form a solid ceramic.

Abstract: The present invention provides a method for conducting a chemical reaction in a non-fluorous medium using a fluorous compound in the presence of a solid adsorbant containing a fluorous domain and at least one chemical reactant, comprising contacting the fluorous compound and at least one chemical reactant under conditions that form at least one product.

Abstract: A filler material that includes a metal fluoride compound which is coated with silica. The filler material can be used in various types of covering agents.

Abstract: The method of making a single crystal, especially a CaF2 single crystal, includes tempering, in which the crystal is heated at <18 K/h to a temperature of 1000° C. to 1350° C. and held at this temperature for at least 65 hours with maximum temperature differences within the crystal of <0.2 K. Subsequently the crystal is cooled with a cooling rate of at maximum 0.5 K/h above a limiting temperature between 900° C. to 600° C. and then further below this limiting temperature at maximum 3 K/h. The obtained CaF2 crystals have refractive index uniformity <0.025×10?6 (RMS) in a (111)-, (100)- or (110)-direction and a stress birefringence of less than 2.5 nm/cm (PV) and/or a stress birefringence of less than 1 nm/cm (RMS) in the (100)- or (110)-direction. In the (111)-direction the stress birefringence is <0.5 nm/cm (PV) and/or the stress birefringence is <0.15 nm/cm (RMS).

Abstract: A process for treating a composition comprising one or more desired (hydro)halocarbons and one or more undesired sulphur containing impurities so as to reduce the concentration of at least one undesired sulphur containing impurity, the process comprising contacting the composition with an adsorbent comprising an acid stable molecular sieve having a pore size of from 2 to 10 ? and/or an activated carbon.