Preparation method for lime nitrogen

Abstract

The invention specifically relates to a preparation method for lime nitrogen, belonging to the field of chemical engineering. According to the preparation method, a raw material containing calcium carbonate and a raw material containing ammonia gas are used and subjected to a calcining reaction in a high-temperature reaction furnace for preparation of lime nitrogen. The lime nitrogen produced by using the method is low in energy consumption and production cost, high in the contents of active ingredients, low in impurity content and shallow in color; and calcium recovered after production of cyanamide from the lime nitrogen can be subjected to secondary development to realize valued utilization, so the target of circular economy is achieved.

Description

technical field

[0001] The invention belongs to the field of chemical industry, and in particular relates to a method for preparing lime nitrogen. Specifically, raw materials containing calcium carbonate and raw materials containing ammonia are used for calcining reaction in a high-temperature reaction furnace to prepare lime nitrogen. Background technique

[0002] Lime nitrogen, also known as calcium cyanamide, is a raw material for the production of cyanamide, dicyandiamide, thiourea, and carbendazim. It can be used as a metal heat treatment agent in iron and steel operations, and can be used as a base fertilizer in agriculture. At present, the consumption of lime nitrogen used in the production of cyanamide and dicyandiamide in my country accounts for 60% of the total consumption of lime nitrogen, and the consumption of thiourea and carbendazim accounts for about 35% of the total consumption of lime nitrogen. The consumption in the agricultural field only accounts for abou...

Examples

Embodiment 1

[0023] A kind of preparation method of lime nitrogen, concrete steps are as follows:

[0024] Place industrial light calcium carbonate in a high-temperature reaction furnace, feed ammonia gas 140 times the amount of calcium carbonate, and perform high-temperature calcination reaction at 400°C for 24 hours under an atmospheric pressure, and cool to room temperature after the reaction is completed. Material, the product is white or off-white solid powder, 33% of available nitrogen of calcium cyanamide is obtained, the content is 94.29%, and the yield is 92.04%.

Embodiment 2

[0026] A kind of preparation method of lime nitrogen, concrete steps are as follows:

[0027] Place industrial light calcium carbonate in a high-temperature reaction furnace, pass through ammonia gas 50 times the amount of calcium carbonate, carry out high-temperature calcination reaction at a pressure of -0.03MPa and a temperature of 700°C for 40 hours, and cool to room temperature after the reaction Discharging, the product is white or off-white solid powder, and 23% of calcium cyanamide available nitrogen is obtained, the content is 65.71%, and the yield is 57.29%.

Embodiment 3

[0029] A kind of preparation method of lime nitrogen, concrete steps are as follows:

[0030] Place industrial light calcium carbonate in a high-temperature reaction furnace, feed ammonia gas 200 times the amount of calcium carbonate, and perform a high-temperature calcination reaction at a pressure of -0.05MPa and a temperature of 350°C for 80 hours, and cool to room temperature after the reaction Discharging, the product is white or off-white solid powder, 25% of calcium cyanamide available nitrogen is obtained, the content is 71.43%, and the yield is 63.64%. .

technical field

[0001] The invention belongs to the field of chemical industry, and in particular relates to a method for preparing lime nitrogen. Specifically, raw materials containing calcium carbonate and raw materials containing ammonia are used for calcining reaction in a high-temperature reaction furnace to prepare lime nitrogen. Background technique

[0002] Lime nitrogen, also known as calcium cyanamide, is a raw material for the production of cyanamide, dicyandiamide, thiourea, and carbendazim. It can be used as a metal heat treatment agent in iron and steel operations, and can be used as a base fertilizer in agriculture. At present, the consumption of lime nitrogen used in the production of cyanamide and dicyandiamide in my country accounts for 60% of the total consumption of lime nitrogen, and the consumption of thiourea and carbendazim accounts for about 35% of the total consumption of lime nitrogen. The consumption in the agricultural field only accounts for abou...

Examples

Embodiment 1

[0023] A kind of preparation method of lime nitrogen, concrete steps are as follows:

[0024] Place industrial light calcium carbonate in a high-temperature reaction furnace, feed ammonia gas 140 times the amount of calcium carbonate, and perform high-temperature calcination reaction at 400°C for 24 hours under an atmospheric pressure, and cool to room temperature after the reaction is completed. Material, the product is white or off-white solid powder, 33% of available nitrogen of calcium cyanamide is obtained, the content is 94.29%, and the yield is 92.04%.

Embodiment 2

[0026] A kind of preparation method of lime nitrogen, concrete steps are as follows:

[0027] Place industrial light calcium carbonate in a high-temperature reaction furnace, pass through ammonia gas 50 times the amount of calcium carbonate, carry out high-temperature calcination reaction at a pressure of -0.03MPa and a temperature of 700°C for 40 hours, and cool to room temperature after the reaction Discharging, the product is white or off-white solid powder, and 23% of calcium cyanamide available nitrogen is obtained, the content is 65.71%, and the yield is 57.29%.

Embodiment 3

[0029] A kind of preparation method of lime nitrogen, concrete steps are as follows:

[0030] Place industrial light calcium carbonate in a high-temperature reaction furnace, feed ammonia gas 200 times the amount of calcium carbonate, and perform a high-temperature calcination reaction at a pressure of -0.05MPa and a temperature of 350°C for 80 hours, and cool to room temperature after the reaction Discharging, the product is white or off-white solid powder, 25% of calcium cyanamide available nitrogen is obtained, the content is 71.43%, and the yield is 63.64%. .

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