CS277226B6 - Method of production of liquid nitrogen fertilizers - Google Patents

Abstract

The subject of the solution is a new method of producing liquid nitrogen fertilizer based on ammonium nitrate and urea. Its essence lies in the fact that urea is treated with such an amount of nitric acid with a concentration of 40 to 60% by weight that the weight ratio of urea: nitric acid is 1:0.8 to 1.3, and the urea nitrate solution thus formed is saturated with gaseous ammonia until a pH value of 7 to 8 is reached. The solution effectively uses the heat of dissolution of urea, while also minimizing ammonia losses.

Description

The invention relates to a process for liquid nitrogen fertilizers.

Previously used methods for the production of liquid nitrogen fertilizers, which is a mixture of ammonium nitrate and urea solutions, use ammonium nitrate and urea in solid form or in solution as basic raw materials. Ammonium nitrate for fertilizer production can be prepared by neutralizing nitric acid with ammonia. Due to the high temperatures during neutralization, ammonia escapes and thus losses. In addition, neutralization production equipment and ammonium nitrate solution tanks must be taken into account. The purchase of solid ammonium nitrate is less economically advantageous.

This disadvantage is eliminated by the process for the production of a liquid nitrogen fertilizer according to the invention, the essence of which consists in that the urea is treated with such an amount of nitric acid in a concentration of 40 to 60% by weight the urea nitrate solution thus formed is saturated with ammonia gas until a pH of 7 to 8 is reached.

The advantage of the process according to the invention is the efficient use of the heat of dissolution of urea and the division of the overall thermal color of the liquid fertilizer preparation into two successive phases with a better possibility of temperature control. This fact has a favorable effect on the losses of ammonia, which can be used in this way according to the invention in other types of machinery, e.g. used in the production of NPK fertilizers, e.g. U-reactors.

To further illustrate the invention, the following example is provided.

Example

Urea and nitric acid at a concentration of 50% by weight are metered into the flow-stirred U-reactor at the same time. The molar ratio of the dosed components is 1: 1, which corresponds to a weight ratio of urea: nitric acid (100%) of 1: 1.05. The resulting reaction slurry proceeds to other U-reactors, where the components are thoroughly mixed and reacted to a suspension of urea nitrate. In other U-reactors, it is gradually saturated with ammonia gas to form a liquid nitrogen fertilizer. When the pH value reaches 7.5 to 8, the ammonia saturation is terminated. The intensity of ammonia feed to the reaction mass and cooling is controlled so that ammonia does not escape.

Example 2

Urea and at the same time weak nitric acid with a concentration of 50% by weight are fed into the U ”reactor system. 0.9 t of nitric acid is dosed per 100 tons of urea to 100%. After the reaction, the reaction slurry is saturated with 0.243 kg of ammonia gas. When pH 7.7 is reached, the saturation of ammonia is terminated. The finished product is produced in the amount of 3.043 kg based on 1 ton of urea. The assumption of lower ammonia losses is based on lower temperatures in the reacting system and a better possibility of solving the ammonia saturation process.

Claims (1)

PATENT CLAIMS Process for the production of a liquid nitrogen fertilizer containing urea and ammonium nitrate, characterized in that the urea is treated with such an amount of nitric acid at a concentration of 40 to 60% by weight that the weight ratio of urea: nitric acid is 1: 0.8 to 1.3 and the resulting urea nitrate solution is saturated with ammonia gas until a pH of 7 to 8 is reached.