Method for rapidly oxidizing oxalic acid

Abstract

The invention belongs to the technical field of spent fuel post-treatment of plutonium tail ends, and particularly relates to a method for rapidly oxidizing oxalic acid. Nitrous acid is produced in a manner of quantitatively introducing nitrogen oxide into feed liquid. The characteristic that the oxidation power of nitrous acid in a dilute solution is stronger than that of nitric acid is utilized, oxidation of oxalic acid is accelerated, the addition of potassium permanganate and high-temperature heat preservation conditions are not changed, and the original catalytic action of divalent manganese is still kept on the premise that the introduction amount of metal ions is not increased, so that the reaction rate is maximized. Various parameters are determined through a control variable method experiment, and the parameters should meet engineering application requirements. In consideration of adaptability of engineering application of a post-treatment plant, existing parameters are adopted: the flow rate of nitrogen oxide is 3.325-3.675 L / h. The parameters are matched with the actual working conditions of the on-site nitrogen oxide device and the acid adding and seasoning operation. The target of shortening the reaction time to one third of the original reaction time is achieved, and the introduction amount of metal ions is not increased on the basis of the original design.

Description

technical field

[0001] The invention belongs to the technical field of post-processing plutonium tail end of spent fuel, and particularly relates to a method for rapidly oxidizing oxalic acid. Background technique

[0002] The method is applied to the plutonium tail end process of the power reactor spent fuel reprocessing plant, and is used for the rapid oxidation of oxalic acid in the filtration mother liquor of plutonium oxalate. The specific instructions are as follows:

[0003] After the plutonium nitrate feed liquid reacts with oxalic acid and is filtered, the plutonium oxalate filter cake is sent to the drying and roasting unit to prepare plutonium dioxide powder products. Front-end deposition and scarring caused by oxalic acid reflux.

[0004] The original method is to first receive a batch of 240L filtrate mother liquor containing oxalic acid in the storage tank, and generate the catalyst Mn by adding an appropriate amount of potassium permanganate. 2+ To realize t...