A method for preparing low-chloride lutetium oxide

Abstract

The invention discloses a method for preparing low-chloride lutetium oxide, which comprises the following steps: (1) Preparation of feed liquid: LuCl with a concentration of 0.1-0.8 mol / L 3 The solution is mixed with the concentrated nitric acid solution to form a feed liquid with a stable concentration. The concentration of nitrate in the feed liquid is 0.3~2.0mol / L; (2) Precipitant preparation: use oxalic acid solution with a concentration of 120~150g / L, Completely dissolve the solid oxalic acid in the oxalic acid solution to make a precipitant; (3) Chlorine removal by precipitation: use the co-current precipitation method to mix the bottom water, the above-mentioned feed liquid and the above-mentioned precipitant at a temperature of 35~60°C to react and precipitate , so that the stoichiometric ratio of lutetium chloride and oxalic acid input into the reaction is n(lutetium chloride):n(oxalic acid)=1: (1.65~1.95); (4) washing and removing chlorine radicals: washing the precipitate lutetium oxalate ; (5) Burning: burn the washed precipitate lutetium oxalate to obtain low-chloride lutetium oxide products to prevent chloride ion wrapping and powder agglomeration during the precipitation of lutetium oxalate, resulting in high impurities.

Description

technical field [0001] The invention belongs to the field of rare earth materials, and relates to a method for preparing low-chloride lutetium oxide, which is a preparation method of rare earth oxides. Background technique [0002] Positron Emission Computed Tomography (PET) system is widely used in the diagnosis and differential diagnosis of various diseases, disease judgment, curative effect evaluation, organ function research and new drug development, etc. In the PET system, background events caused by spontaneous emission of scintillation crystals, unreal random coincidence events and background noise caused by scattered coincidence events may have a great impact on the image signal-to-noise ratio. Therefore, the PET system usually adopts the following methods to ensure the signal-to-noise ratio of the image: reducing spontaneous emission and improving the energy resolution of the system. Among these methods, improving the quality index of scintillation crystal is a way...

AI Technical Summary

Problems solved by technology

The impact of impurity ions in lutetium oxide products on crystal performance is also particularly important. According to relevant literature reports, impurity ions will directly affect the light output of rare earth scintillation crystals LSO or LYSO, and affect the efficiency of PET testing. The main impurity ions in lutetium oxide are Chloride ions, chloride ions have negative 1 valence, while oxygen ions in rare earth scintillation crystals LSO or LYSO have negative 2 valences. When lutetium oxide is used to make scintillation crystals, chloride ions will replace oxygen ions, causing crystal defects and affecting crystal performance.

[0004] At present, the content of chloride radicals in lutetium oxide prepared by precipitation method is about 100~200ug / g, and the situation of chloride radical encapsulation is very easy to occur during the precipitation process of lutetium oxide, resulting in high chloride radicals in lutetium oxide after burning

However, the use of lutetium oxide for secondary precipitation through nitric acid redissolution will lead to problems such as reduced product yield and increased cost.