阅读说明：本技术 一种制备硝酸铵的方法 (Method for preparing ammonium nitrate ) 是由 陈志敏 李江 景银兰 于 2021-01-22 设计创作，主要内容包括：本发明涉及无机化工领域,具体涉及一种制备硝酸铵的方法；以氨水为原料,以过氧化氢为氧化剂,以含钨化合物为催化剂,一锅法制备硝酸铵；氨水是常见的无机化工原料,在反应过程中反应体系中逸出的氨可回收重复利用或用硝酸吸收生成硝酸铵；过氧化氢是一种对环境友好的清洁氧化剂,过量的过氧化氢很容易分解为氧气和水,不会给反应体系引入新的杂质。且该方法为一锅法,反应条件温和,操作简单,无需特殊的设备,不产生对环境有害的废弃物,可望成为硝酸铵的一种清洁、安全的制备方法。(The invention relates to the field of inorganic chemical industry, in particular to a method for preparing ammonium nitrate; preparing ammonium nitrate by a one-pot method by taking ammonia water as a raw material, hydrogen peroxide as an oxidant and a tungsten-containing compound as a catalyst; ammonia water is a common inorganic chemical raw material, and ammonia escaping from a reaction system in the reaction process can be recycled or absorbed by nitric acid to generate ammonium nitrate; the hydrogen peroxide is an environment-friendly clean oxidant, and the excessive hydrogen peroxide is easily decomposed into oxygen and water without introducing new impurities into a reaction system. The method is a one-pot method, has mild reaction conditions, simple operation, no need of special equipment and no generation of wastes harmful to the environment, and is expected to become a clean and safe preparation method of ammonium nitrate.)

1. The method for preparing ammonium nitrate is characterized in that ammonia water is used as a raw material, hydrogen peroxide is used as an oxidant, and a tungsten-containing compound is used as a catalyst to prepare ammonium nitrate by a one-pot method.

2. The method for preparing ammonium nitrate according to claim 1, wherein the catalyst is one or more of sodium tungstate, phosphotungstic acid, silicotungstic acid and tungstic acid.

3. The method for preparing ammonium nitrate according to claim 1, wherein the mass concentration of the ammonia water is 25-28%, and the amount of the catalyst is 0.25-4% of the mass of the ammonia water.

4. The method for preparing ammonium nitrate according to claim 2, wherein the catalyst is used in an amount of 1% by mass of ammonia water having a mass concentration of 25% to 28%.

5. The method for preparing ammonium nitrate according to claim 1, wherein the concentration of the hydrogen peroxide is 30% by mass, and the amount of the hydrogen peroxide is excessive relative to the amount of the raw material ammonia water.

6. The method for preparing ammonium nitrate according to claim 1, wherein the mass ratio of hydrogen peroxide to ammonia is 2.6: 1.

7. The method for preparing ammonium nitrate according to claim 1, wherein the reaction temperature is 0 ℃ to 90 ℃.

Technical Field

The invention relates to the field of inorganic chemical industry, in particular to a method for preparing ammonium nitrate.

Background

Ammonium nitrate is an important inorganic chemical product used for producing laughing gas and fireworks, and is used as fertilizer, military explosive, pesticide, refrigerant, oxidant, analytical reagent, nitrogen oxide absorbent, etc.

The preparation method of ammonium nitrate mainly comprises the following two methods:

the neutralization method takes ammonia and nitric acid as raw materials. The reaction principle is as follows:

NH₄OH+HNO₃→NH₄NO₃+H₂O

the conversion method uses ammonium carbonate and calcium nitrate as raw materials. The reaction principle is as follows:

the conversion method is characterized in that a byproduct calcium nitrate tetrahydrate generated in the production process of a nitrophosphate fertilizer is used as a raw material and reacts with an ammonium carbonate solution to generate ammonium nitrate and calcium carbonate precipitates, the ammonium nitrate and the calcium carbonate precipitates are limited by the raw material and are rarely used, and calcium carbonate waste is generated.

In the neutralization method, nitric acid is generally used at a concentration of 50% to 68% or more, resulting in a severe exothermic reaction, imposing severe requirements on equipment, and being susceptible to explosion accidents. And the raw material nitric acid used in the neutralization method is generally prepared by an ammonia catalytic oxidation method, and has harsh reaction conditions and explosion danger.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides a method for preparing ammonium nitrate.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a method for preparing ammonium nitrate, which takes ammonia water as raw material, hydrogen peroxide as oxidant and tungsten-containing compound as catalyst, prepares ammonium nitrate by one-pot method.

The reaction principle is as follows:

NH₃·H₂O+HNO₃→NH₄NO₃+H₂O

the total reaction is as follows:

further, the catalyst is one or more of sodium tungstate, phosphotungstic acid, silicotungstic acid and tungstic acid.

Furthermore, the mass concentration of the ammonia water is 25-28%, and the dosage of the catalyst is 0.25-4% of the mass of the ammonia water.

Preferably, the amount of the catalyst is 1% by mass of ammonia water having a mass concentration of 25% to 28%.

Further, the mass concentration of the hydrogen peroxide is 30%, the amount of the hydrogen peroxide is excessive relative to the amount of the raw material ammonia water, and the excessive hydrogen peroxide can be decomposed into oxygen and water in the evaporation crystallization process of the ammonium nitrate.

Preferably, the mass ratio of hydrogen peroxide to ammonia is 2.6: 1.

Further, the reaction temperature is 0-90 ℃. The higher the temperature, the greater the reaction rate, but at the same time the greater the rate of decomposition of the hydrogen peroxide and the degree of volatilization of the ammonia, so that the yield of ammonium nitrate is rather reduced. Taking into consideration all the factors, it is recommended that the reaction be carried out at room temperature, so that the cost for heating can be eliminated.

Compared with the prior art, the invention has the following beneficial effects:

ammonia water is a common inorganic chemical raw material, and ammonia escaping from a reaction system in the reaction process can be recycled or absorbed by nitric acid to generate ammonium nitrate; the hydrogen peroxide is an environment-friendly clean oxidant, and the excessive hydrogen peroxide is easily decomposed into oxygen and water without introducing new impurities into a reaction system. The method is a one-pot method, has mild reaction conditions, simple operation, no need of special equipment and no generation of wastes harmful to the environment, and is expected to become a clean and safe preparation method of ammonium nitrate.

Detailed Description

The present invention is further illustrated by the following specific examples.

The operation steps adopted in the invention are as follows:

adding catalyst, hydrogen peroxide and ammonia water into a round-bottom flask with a reflux condenser tube in sequence, and reacting at a selected water bath temperature until the pH of the reaction solution is less than or equal to 7 (tested by using a wide pH test paper), or the reaction solution does not contain hydrogen peroxide (tested by using a starch-potassium iodide test paper). Pouring the reaction liquid after the reaction into an evaporating dish, evaporating and crystallizing in water bath, drying the obtained crystal in an oven at 50 ℃ for a certain time, and putting the crystal into a dryer to be cooled to room temperature. Weighing and calculating the yield.

Example 1

0.0679gNa was added sequentially to a 50mL round bottom flask equipped with a water bath, reflux condenser₂WO₄·2H₂O, 26mL of 30% (mass concentration) hydrogen peroxide and 7.6mL of 25% -28% (mass concentration) ammonia water, heating to 50 ℃ in a water bath, and keeping the temperature to react until the pH value is 6 (reacting for 18 hours in total). Pouring the reaction solution into an evaporating dish, evaporating the reaction solution in water bath for crystallization, drying the obtained crystals in an oven at 50 ℃ for 1 hour, and putting the crystals into a dryer to be cooled to room temperature. 3.2776g of a white solid are obtained in yield (as NH)₃Calculated) 81.94 percent.

Example 2

0.0694g of Na was added in sequence to a 100mL Erlenmeyer flask with a glass stopper₂WO₄·2H₂O, 20mL of 30% (mass concentration) hydrogen peroxide and 7.6mL of 25% -28% (mass concentration) ammonia water, and reacting at room temperature (15 ℃ -18 ℃) until starch-potassium iodide paper is unchanged (reacting for 3 days in total). Pouring the reaction solution into an evaporating dish, evaporating the reaction solution in water bath for crystallization, drying the obtained crystals in an oven at 50 ℃ for 30 minutes, and putting the crystals into a dryer for cooling to room temperature. 3.2192g of a white solid are obtained in yield (as NH)₃Calculated) 80.48 percent.

Example 3

0.0695g of Na was sequentially added to a 100mL Erlenmeyer flask with a glass stopper₂WO₄·2H₂O, 26mL of 30% (mass concentration) hydrogen peroxide and 7.6mL of 25% -28% (mass concentration) ammonia water, and reacting at room temperature (9 ℃ -14 ℃) until the pH becomes 6 (total reaction time: 11 days). Pouring the reaction solution into an evaporating dish, evaporating the reaction solution in water bath for crystallization, drying the obtained crystals in an oven at 50 ℃ for 1 hour, and putting the crystals into a dryer to be cooled to room temperature. 3.4668g of a white solid are obtained in yield (as NH)₃Calculated) 86.67%.

Example 4

0.0675g of silicotungstic acid, 26mL of 30% (mass concentration) hydrogen peroxide and 7.6mL of 25% -28% (mass concentration) are sequentially added into a 50mL round-bottom flask provided with a water bath and a reflux condenser tube) Heating ammonia water in a water bath to 50 ℃, and keeping the temperature to react until the pH value is 7 (the total reaction time is 15.5 hours). Pouring the reaction solution into an evaporating dish, evaporating the reaction solution in water bath for crystallization, drying the obtained crystals in an oven at 50 ℃ for 1 hour, and putting the crystals into a dryer to be cooled to room temperature. 3.2321g of a white solid are obtained in yield (as NH)₃Calculated) 80.80 percent.