SU395321A1 - The method of regeneration of hydrochloric acid - Google Patents

Description

one

The invention relates to methods for the regeneration of hydrochloric acid from spent pickling solution.

A known method for the regeneration of hydrochloric acid from spent hydrochloric acid

pickling solution by high-temperature oxidative hydrolysis. In this method, oxidative hydrolysis is carried out by heating the solution with a stream of hot gases to 8OO-9OO C in a fluidized bed of inert material supported by this stream. The solution is fed to the fluidized bed after partial partial evaporation, and the flow rate of hot gases is kept constant over the entire height of the fluidized bed. The particle size of the inert material is 0.2-2 mm.

However, this method is characterized by a relatively low intensity of the process. So, when regenerating the spent pickling solution containing about 25% ferric chloride, the specific equipment capacity (in solution) does not exceed 15O l / m hour of the reactor working volume. The specific energy consumption is relatively high due to the high temperature at which the process is carried out.

In order to intensify the process, the flow rate of hot gases supporting the fluidized bed is proposed to be set within such limits that its value at the entrance to the fluidized bed exceeds the rate at the exit of it 3.5-6.5 times. Heating up 25% the solution is produced up to a temperature of not more than 450-60 ° C. The inert material is granules with an average size of 3-15 mm.

During the implementation of the process by the proposed method, its intensity increases significantly, since the specific productivity of the equipment increases (to a value of more than 25 l / m.h of the working volume of the reactor).

Claims (2)

At the same time, reducing the operating temperature of the process also reduces the unit cost of energy. In addition, there is no need for preliminary partial evaporation of the initial pickling solution. i Example The spent 25% ferric chloride pickling solution is regenerated in a fluidized bed reactor of porcelain balls with a diameter of 5-6 mm. The rate of hot flue gases, by which the fluidized bed is maintained and the oxidative hydrolysis is carried out, is adjusted so that it is 4 times as high as the speed at the upper point of the fluidized bed. The solution is fed into the reactor at a rate of 100 O l / h, the operating temperature is maintained at about 450-500 C. Obtained in a water-irrigated absorber by trapping the gases from the reactor, hydrochloric acid has a concentration of 18–20%. The solid particles recovered in the cyclone are 98-99% iron oxide. The formula was invented by 1. A method of regenerating hydrochloric acid from spent hydrochloric acid pickling solution by high-temperature oxidative hydrolysis, carried out by heating the solution with a stream of hot gases in a fluidized bed of inert material supported by this stream, characterized in that, to intensify the process, the flow rate of hot gases is established within the following limits: so that its value at the entrance to the fluidized bed exceeds the value of the rate at the exit from it 3.5-6.5 times, and heating products produced up to 450-60 ° C. 2. A method according to claim 1, characterized in that the inert material is granules with an average size of 3-15 mm.