Method for preparing ferrous nitrate solution by adopting liquid-solid phase moving bed reaction device

Abstract

The invention discloses a method for preparing ferrous nitrate solution by adopting a liquid-solid phase moving bed reaction device. In the method, iron sheets, water and nitric acid are taken as raw materials, reaction is carried out in the liquid-solid phase moving bed reaction device, the reaction time is 4 hours-12 hours, the reaction device comprises a reactor and a circulating pump; the reactor comprises a shell, an inner drum, a partition board, a circulating outlet, a material inlet, an acid inlet and a material outlet, wherein the acid inlet is arranged between the shell and the inner drum; the shell is formed by connecting a cylindrical section and a conical section; the partition board is arranged at the lower part of the cylindrical section; the inner drum is fixed on the partition board; the partition board at the bottom of the inner drum is provided with distributing holes; the material inlet is arranged at the upper part of the cylindrical section; the circulating outlet is arranged on the shell above the partition board; the material outlet is arranged at the bottom of the conical section; an inlet of the circulating pump is connected with the circulating outlet; and an outlet of the circulating pump is connected with the material outlet. In the method, the generation of high-valence iron and nitric oxides can be reduced, no slag and iron scrap are deposited, the system temperature is convenient to control, and the reaction time is shortened.

Description

Technical field [0001] The invention relates to a preparation method of ferrous nitrate solution. Background technique [0002] Ferrous nitrate solution is a basic raw material for the preparation of (iron oxide pigment). [0003] In the current production method, the ferrous nitrate solution is carried out in a horizontal reactor. The horizontal reactor is provided with a plurality of reaction chambers connected in series. The reaction chambers are separated by a stainless steel plate with perforations. There is a stainless steel bottom plate with larger holes at the bottom. For a production process with four reaction chambers, the reaction process is as follows: add iron sheet and water to the first 1-3 reaction chambers, then slowly add low-concentration dilute nitric acid to the first reaction chamber of the reactor, and then enter the 2~3 reactions in sequence In the fourth reaction chamber, the bottom of the fourth reaction chamber is pumped out and the material is pumped i...

AI Technical Summary

Problems solved by technology

[0005] 1. The distribution of materials is uneven, there are short circuits or dead ends in circulation, and the local concentration at the place where nitric acid is added is too high, which is easy to produce high-valent iron, including by-products such as ferric nitrate or its hydrolyzed product, ferric hydroxide, etc. The concentration of high-valent iron is 0.1-0.3g / 100ml

[0006] 2. Due to the horizontal equipment, the bottom is easy to deposit solid matter, which is difficult to clean up, and it is covered on the iron sheet to prevent the acid from contacting the iron sheet and reduce the reaction efficiency;

[0007] 3. The volume of the equipment is fixed, the liquid level is low in the early stage, and the iron sheet is exposed outside, so it is easy to directly contact with acid to generate high-valent iron and nitrogen oxides (nitrogen monoxide and nitrogen dioxide gas) to pollute the environment, and there is obvious "yellow smoke" (two nitrogen oxide gas)

[0008] 4. The volume changes greatly before and after the reaction, and the heat dissipation is different, so it is difficult to control the temperature

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