摘要:
A process for producing a porous glass preform for optical fiber by depositing fine glass particles on an outer surface of a glass material while moving the glass material, including the steps of: preheating a portion of the glass material for not less than 5 minutes to clean the portion of the glass material in an apparatus for depositing fine glass particles; and depositing fine glass particles on the portion of the glass material cleaned by the preheating, in the apparatus for depositing fine glass particles.
摘要:
A method for neutralizing a sulfuric acid solution containing predominantly Zn ion, comprising adding, to the sulfuric acid solution, at least one compound selected from the group of chlorine-containing compounds of Na ion, K ion, Mg ion, Ca ion, and NH.sub.4 ion in an amount at least chemically equivalent to SO.sub.4 ion contained; and then bringing the sulfuric acid solution into contact with an organic solvent composed of one or more species selected from the group of oxygen-containing organic solvents and alkylamine organic solvents to extract Zn ion from the sulfuric acid solution as a chloride complex to the organic solvent. The sulfuric acid solution after extraction of Zn ion is further treated by addition of an oxidizing agent or by an electrochemical means to convert Fe.sup.2+ into to Fe.sup.3+ ion and is brought into contact with a second organic solvent B composed of one or more species selected from the group of oxygen-containing organic solvents and alkylamine organic solvents to extract Fe ion from the sulfuric acid solution as a second chloride complex to the second orgaic solvent B.
摘要:
A process for recovery of reusable chromic acid from waste chromic acid solution containing impurities, which process comprises a first step in which the solution containing chromic acid is introduced into the cathode compartment in an electro-dialysis process and free chromic acid or chromate ions in the above solution are transferred to the anode compartment, a second step in which H.sub.2 SO.sub.4 is added in at least equivalent amounts to the heavy metallic ion contained in the outlet solution, in which chromic acid ion concentration is reduced, in order to convert chemical species of the contained metallic ion and increase the H.sup.+ ion concentration and then chromate ions in the resultant solution are extracted into an organic phase with contact of an organic solvent (A), and a third step in which residual amounts of chromic acid ion remaining in the aqueous raffinate from the second step are extracted into an organic phase with contact of an organic solvent (B). Organic solvents A and B are regenerated by stripping the organic phase with a suitable strip reagent.
摘要翻译:从含有杂质的废铬酸溶液中回收可再利用的铬酸的方法,该方法包括第一步骤,其中将含有铬酸的溶液在电渗析过程中引入阴极室,并且将游离的铬酸或铬酸根离子 将上述溶液转移到阳极室,第二步骤,其中以至少等量的量加入H 2 SO 4,其中所述重金属离子包含在出口溶液中,其中铬酸离子浓度降低,以便将化学物质转化为 含有金属离子并增加H +离子浓度,然后将所得溶液中的铬酸根离子与有机溶剂(A)接触而萃取到有机相中,并且残留在残液中的残余量的铬酸离子的第三步骤 从有机溶剂(B)与第二步骤萃取到有机相中。 有机溶剂A和B通过用合适的剥离试剂汽提有机相来再生。
摘要:
The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, provided on the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is 0.30% or more but 0.50% or less, and the relative refractive index difference of the inner cladding with respect to the outer cladding is −0.50% or more but −0.02% or less. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective area of 70 &mgr;m2 or more at the wavelength of 1.55 &mgr;m.
摘要:
A sport shoe in which the shoe sole is bonded to an insert layer during the formation of the shoe sole by injection-molding and the assembly of the shoe sole and the insert layer is secured to the shoe upper by an adhesive applied between the insert layer and the shoe upper.
摘要:
This invention relates to a process for recovery of waste H.sub.2 SO.sub.4 and HCl which are used for pickling metallic materials and articles and contain a large quantities of Fe ions. Furthermore, it offers a process for the recovery of H.sub.2 SO.sub.4 and HCl from waste H.sub.2 SO.sub.4 which contains large amounts of Fe ions after removal of Ti ions by a hydrolysis process in the production of TiO.sub.2 and also for the recovery of high-purity electrolytic iron or iron hydroxide.
摘要:
Process for producing fluorides of Mo, W, Nb, Ta, V, Re, Ti, Zr, Hf, Co, Ni, Cr, Sb, Sn, Zn, Pb, Al and rare earth metals comprising heating fluorine-containing ammonium salts of corresponding metals in a stream of an inert or reducing gas to convert them into fluorides of the metals.
摘要:
A crystallizer comprising a mixing zone of an organic solvent containing ions of a metal extracted therein and an aqueous separating solution provided at the upper part of a main crystallizer body, a lower-part opened organic solvent settling zone provided outside of the mixing zone for receiving and settling the organic solvent overflowing out of the mixing zone, a crystals developing zone having a downwardly narrowing cross section provided at the lower part of the main crystallizer body, a descending pipe extending from the lower end of the mixing zone to the lower part of the crystals developing zone, a crystals fluidizing medium inlet provided at the lower end of the crystals developing zone, a separating solution discharge pipe and a crystals discharge pipe. By applying an aqueous separating solution, in which the solubility of the metallic salt in object is small, for transferring metal ions in an organic solvent therein, it is possible to obtain the crystals of said metallic salt with no need of concentrating the separating solution by evaporation.
摘要:
A process for selectively stripping and separating iron ions from an organic solvent (A) which comprises bringing the organic solvent (A) containing iron and zinc ions, and containing one or more compounds selected from the group consisting of alkyl phosphoric acid, alkyl-aryl phosphoric acid, alkyl thio phosphoric acid and alkyl-aryl thio phosphoric acid together with a petroleum hydrocarbon as a diluent, into contact with an aqueous solution containing NH.sub.4.sup.+ and F.sup.- ions so as to selectively strip the iron ions into the aqueous solution despite the coexistence of zinc ions.