摘要:
Solutions such as for example groundwater, drinking water, extracting solutions and effluents contaminated with metals, radioactive species and organics, singly or in combination, are treated by first removing undesirable oxidizing agents from the contaminated solution. Then the contaminated solution is separately treated with aqueous solutions of ferrous sulfate and hydroxide, which precipitate substantially all of the contaminants. Next, the precipitate is treated with a flocculant and/or a coagulant to form an easily dewaterable and separable solid. The solid contaminants are readily removed from the cleansed solution. The process utilizes a novel combination of steps which maximizes contaminant removal, minimizes waste volume, and produces a recyclable solution and a manageable waste stream. The preferred hydroxide solutions are sodium hydroxide, calcium hydroxide, and ammonium hydroxide.
摘要:
This is a method of reducing zirconium chloride to a metal product by introducing zirconium chloride into a molten salt bath containing at least one alkali metal chloride and at least one alkaline earth metal chloride; and electrochemically reducing alkaline earth metal chloride to a metallic alkaline earth metal in the molten salt bath, with the reduced alkaline earth metal reacting with the zirconium chloride to produce zirconium metal. By using this electrochemical-metallothermic reduction, zirconium metal is produced and insoluble subchlorides of zirconium in the metal product are generally avoided.Preferably, the molten salt in the molten salt bath consists essentially of a mixture of lithium chloride, potassium chloride, magnesium chloride and zirconium or hafnium chloride. The method is especially useful as part of a distillation system for separating hafnium from zirconium, possibly after the zirconium chloride is removed from the distillation system, but especially where the distillation system has an alkali metal chloride and alkaline earth metal chloride recirculating solvent and the electrochemical-metallothermic reduction is used to strip the solvent of zirconium chloride.This process can also be used for hafnium and titanium, especially when a powder metal product is desired.