Efficient self-recycling system for continuously preparing sodium bichromate by wet method

Abstract

The invention discloses an efficient self-recycling system for continuously preparing sodium bichromate by a wet method. The system comprises a beating tank, an oxygen supply device, and a first delivery pump, a preheating device, a liquid-phase oxidation reaction device, a flash evaporation device, a first separation device, a first concentration device, a carbonization device, a second separation device, an electrolytic bath, a second concentration device, a cooling crystallization device and a centrifugation device, which are sequentially connected with the beating tank through a feed liquid delivery pipeline, wherein the oxygen supply device is used for introducing oxygen into the liquid-phase oxidation reaction device; CO2 generated by preheating decomposition, CO2 and steam, which are generated by oxidation, and steam generated by flash evaporation can be delivered to the concentration devices, the steam is used for feed liquid concentration, and CO2 is led into the carbonization device for carbonization reaction; chromium-containing sodium bicarbonate obtained by separation in the second separation device can be delivered to the beating tank as an ingredient. According to the system, the byproducts CO2 and steam are used for carbonization and feed liquid concentration and the product sodium bicarbonate is used as the ingredient, so that sodium, CO2 and heat are efficiently self-recycled, and energy waste is reduced.

Description

technical field [0001] The invention belongs to the field of preparation of sodium bauxite, in particular to a system for continuously preparing sodium bauxite by a high-efficiency self-circulation wet method. Background technique [0002] As the basic product of chromium salt, sodium red alum is one of the important inorganic chemical raw materials. It occupies an important position in the national economy and has a very wide range of uses. The front end of the traditional production process uses chromite, soda ash, slag and other raw materials to be calcined in a rotary kiln at a temperature above 1000 ° C. The roasted clinker is leached to obtain a sodium chromate solution, and the back end uses sulfuric acid to acidify sodium chromate to obtain a red alum sodium solution. After evaporation and crystallization and dehydration, the sodium red alum product is obtained. However, the production process has serious secondary pollution, waste of resources, high energy consumpt...

AI Technical Summary

Problems solved by technology

However, this process has great requirements on production equipment, and the by-product sodium bicarbonate needs to be calcined. The labor intensity increases, the production equipment cannot meet the continuous production, the resources cannot be fully utilized, and the heat recovery and utilization rate generated is low.

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