阅读说明：本技术 一种有机钙盐制备高端石灰氮的方法 (Method for preparing high-end lime nitrogen from organic calcium salt ) 是由 程珍 张建林 高鹏 安敬瑞 李彩葵 于 2020-11-25 设计创作，主要内容包括：本发明涉及化工领域,具体涉及一种有机钙盐制备高端石灰氮的方法。以乙酸钙等含碳有机钙盐为原料,在高温炉中与氨气反应制备石灰氮,反应后产品中有效氮含量高达33%以上,产品成分只有氰胺化钙和氧化钙,产品纯度高,是一种新型的绿色制备方法,能为石灰氮下游制备化工品提供高品质原料。(The invention relates to the field of chemical industry, in particular to a method for preparing high-end lime nitrogen by using organic calcium salt. The method is a novel green preparation method, and can provide high-quality raw materials for preparing chemicals in the downstream of lime nitrogen.)

1. The method for preparing high-end lime nitrogen by using organic calcium salt is characterized in that the organic calcium salt is used as a raw material to react with ammonia gas at the temperature of 300-600 ℃ to prepare the lime nitrogen.

2. The method of claim 1, wherein the organic calcium salt is selected from calcium acetate, calcium propionate, and mixtures thereof.

3. The method for preparing high-end lime nitrogen from organic calcium salt according to claim 1, wherein the reaction temperature is 400-500 ℃.

4. The method for preparing high-end lime nitrogen by using organic calcium salt as claimed in claim 1, wherein the molar ratio of the organic calcium salt to ammonia gas is 1: 20-1: 100.

5. The method for preparing high-end lime nitrogen through organic calcium salt according to claim 4, wherein the molar ratio of the organic calcium salt to the ammonia gas is 1: 40-1: 60.

6. The method for preparing high-end lime nitrogen by using organic calcium salt as claimed in claim 1, wherein the reaction time of the organic calcium salt and ammonia gas is 4-10 h.

7. The method for preparing high-end lime nitrogen by using organic calcium salt as claimed in claim 6, wherein the reaction time of the organic calcium salt and ammonia gas is 6-8 h.

Technical Field

The invention relates to the field of chemical industry, in particular to a method for preparing high-end lime nitrogen by using organic calcium salt.

Background

The lime nitrogen is mainly used as a fertilizer in agriculture, the lime nitrogen can be used for developing fine chemical products, in recent years, various fine chemical products are developed and produced by taking high-end lime nitrogen as a raw material abroad, and the preliminary progress is made, which is mainly shown in the following aspects: 1. synthetic resin, coating: in japan, a variety of flame-retardant resins and flexible resins having water resistance, flame retardancy, and good thermal stability have been developed. 2. Pesticide: lime nitrogen is used in the uk to develop pesticides suitable for corn crops.

The lime nitrogen used as a raw material of a chemical product has high requirement on lime nitrogen, the lime nitrogen sold in the market at present adopts a calcium carbide process, carbon is produced as a byproduct while the lime nitrogen is produced, the lime nitrogen is difficult to separate, the product contains impurities such as calcium carbide, carbon and the like, the product is black powder in appearance, the effective nitrogen content of the product is not more than 23%, and particularly, the chemical property of the calcium carbide is active, so that the quality of fine chemicals prepared in the downstream can be influenced.

Disclosure of Invention

The invention provides a method for preparing high-end lime nitrogen by using organic calcium salt, which is used for preparing the high-end lime nitrogen by using carbon-containing organic calcium salt such as calcium acetate and the like as raw materials and reacting with ammonia gas in a high-temperature furnace, wherein the content of effective nitrogen in a product after reaction is up to more than 33 percent, the product only contains calcium cyanamide and calcium oxide, the product purity is high, and the method is a novel green preparation method and can provide high-quality raw materials for preparing chemical products at the downstream of the lime nitrogen.

The technical scheme of the invention is a method for preparing high-end lime nitrogen by using organic calcium salt, which is used as a raw material to react with ammonia gas at 300-600 ℃ to prepare lime nitrogen.

The organic calcium salt is preferably selected from calcium acetate or calcium propionate or a mixture thereof, and the organic calcium salt of the present invention includes, but is not limited to, the above calcium salts.

The reaction temperature is preferably 400-500 ℃, the reaction is not obviously promoted due to high temperature and high energy consumption, and the reaction efficiency is low due to too low temperature.

The molar ratio of the organic calcium salt to the ammonia gas in the reaction is 1: 20-1: 100, preferably 1: 40-1: 60.

The reaction time of the organic calcium salt and ammonia gas is 4-10 hours, preferably 6-8 hours, the reaction time is too short, the reaction is insufficient, and when the organic calcium salt is completely consumed, the reaction time is prolonged to the end point, so that the time is meaningless.

Compared with inorganic calcium salts such as calcium carbonate and the like, for example 108557843A adopts calcium carbonate as a raw material, the organic calcium salt has more organic group components in molecules, lower bond energy, easier generation of new bonds by breaking old bonds and higher reaction activity, the reaction efficiency of the organic calcium salt is obviously better than that of the calcium carbonate under the same reaction condition, and the reaction conversion rate and the reaction yield are higher.

The high-end lime nitrogen product prepared by the process is white or gray powder, has high product purity and few components, only contains a small amount of calcium oxide except calcium cyanamide, does not contain impurities with active chemical properties such as calcium carbide and the like, and is more suitable for developing fine chemicals in the downstream. The reaction conversion rate of the organic calcium salt can reach 100 percent, the purity of the final product is higher, the content of effective nitrogen is higher and can reach more than 33 percent, and the yield can reach more than 92 percent.

Drawings

FIG. 1 is an XRD analysis spectrum of the product of example 1;

FIG. 2 is an XRD analysis spectrum of a comparative product;

XRD test conditions Cu target, radiation K β, model SmartLab (9 kW), manufacturer: RIGAKU, japan, voltage/current: 40kV, 150 mA; scanning range: wide angle scanning 5 ° -75 °, step width: 0.02, scanning speed: 2 °/min, temperature: room temperature, with fittings: wide angle diffraction measurement accessory, control and analysis software: PDXL, software: PDF 2-2009;

CaCN₂ DB card number01-085-0672；

CaO DB card number00-037-1497；

CaCO₃ DB card number01-086-0174。

Detailed Description

The present invention will be further described with reference to specific examples, but the present invention is not limited to the examples.

Example 1

Adding 1 kg of calcium acetate into a tubular furnace, introducing ammonia gas for replacing for half an hour, heating the temperature to 450 ℃ by program, adjusting the flow of the ammonia gas to 20L/min, maintaining the reaction temperature at 450 ℃ and reacting for 7 hours to finally obtain gray solid powder, namely the lime nitrogen. The total mass of the obtained product is 495 g, and the effective nitrogen content is detectedThe content is 33.1%, and the component of XRD is CaCN₂And CaO, whose XRD pattern is shown in FIG. 1, whereby the conversion rate was 100%, and the yield was calculated to be 92.6%.

Example 2

Adding 1 kg of calcium propionate into a tubular furnace, introducing ammonia gas for replacing for half an hour, heating to 300 ℃ by program, adjusting the flow of the ammonia gas to 16L/min, maintaining the reaction temperature at 300 ℃ and reacting for 10 hours to finally obtain gray solid powder, namely a limemin product. The total mass of the obtained product is 438 g, the content of effective nitrogen is detected to be 31.2 percent, and XRD components are detected to be CaO and CaCN₂From this result, the conversion was 100%, and the calculated yield was 90.9%.

Example 3

Adding 1 kg of calcium acetate into a tubular furnace, introducing ammonia gas for replacing for half an hour, heating to 600 ℃ by program, adjusting the flow of the ammonia gas to 15L/min, maintaining the reaction temperature at 600 ℃ and reacting for 4 hours to finally obtain white solid powder, namely a limemin product. The total mass of the obtained product is 491 g, the detected effective nitrogen content is 32.5 percent, and the detected XRD components are CaO and CaCN₂From this result, the conversion was 100%, and the calculated yield was 90.1%.

Comparative example

Adding 1 kg of calcium carbonate into a tubular furnace, introducing ammonia gas for replacing for half an hour, heating the mixture to 450 ℃ by a program, adjusting the flow of the ammonia gas to 32L/min, maintaining the reaction temperature at 450 ℃ and reacting for 7 hours to finally obtain white solid powder, namely a calcium cyanamide product. The total mass of the obtained product is 826 g, the content of the detected effective nitrogen is 22.3 percent, and the calculated yield is 65.8 percent. The component of the XRD is CaCO₃、CaCN₂And CaO, the XRD spectrum of which is shown in figure 2.

From the above, it can be seen that the product obtained by the example of the present invention has significantly improved effective nitrogen content, significantly improved yield and conversion rate, fewer impurity species, and significantly improved technical process compared to the prior art.