A batching method for integrated production of ammonium calcium nitrate solution

Abstract

This invention belongs to the chemical industry, specifically relating to an integrated method for producing calcium ammonium nitrate solution. The method includes S1, mixing dilute calcium nitrate solution and nitric acid solution in a specific ratio to obtain a mixed solution; S2, introducing an ammonia solution into the mixed solution to initiate a reaction, and obtaining the calcium ammonium nitrate solution after the reaction. The flow rate of the dilute calcium nitrate solution is the primary parameter, and the flow rate of the nitric acid solution is adjusted proportionally based on the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is also adjusted proportionally based on the flow rate of the nitric acid solution. The method provided by this invention involves mixing filtrate and nitric acid solution, then introducing ammonia solution, and reacting to obtain the dilute calcium ammonium nitrate solution. The entire process does not require the hazardous chemical ammonium nitrate solution, ensuring production safety and promoting the development of calcium ammonium nitrate production enterprises.

Description

Technical Field

[0001] This invention belongs to the field of chemical engineering, and in particular relates to an integrated method for preparing ammonium calcium nitrate solution. Background Technology

[0002] Calcium ammonium nitrate is a compound fertilizer with the chemical formula (5Ca(NO3)2·NH4NO3·10H2O). It is a white, round granular fertilizer that is highly soluble in water. It exhibits strong hygroscopicity, caking properties, and is flammable and explosive. It is a new type of high-efficiency compound fertilizer containing nitrogen and fast-acting calcium. It has a rapid fertilizing effect, providing quick nitrogen replenishment. The added calcium makes it more comprehensive in nutrients than ammonium nitrate, and it can be directly absorbed by plants. Calcium ammonium nitrate has a wide range of applications, suitable for various soils and crops, and is widely used in greenhouse and field cultivation of grain crops, cash crops, flowers, fruit trees, and vegetables. The nitrate nitrogen in calcium ammonium nitrate does not require prior conversion in the soil but dissolves rapidly in water for direct absorption by plants, making it suitable as a base fertilizer, seed fertilizer, and top dressing.

[0003] Currently, the production process of calcium ammonium nitrate in China mainly involves mixing dilute calcium nitrate solution and dilute ammonium nitrate solution in a certain proportion. However, ammonium nitrate solution is a key hazardous chemical under national supervision. Therefore, there is an urgent need for a calcium ammonium nitrate production process that can replace ammonium nitrate solution. Summary of the Invention

[0004] The main objective of this invention is to provide an integrated method for preparing ammonium calcium nitrate solution, thereby overcoming the shortcomings of the prior art.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0006] According to one aspect of the present invention, an integrated method for producing calcium ammonium nitrate solution is provided, comprising the following steps:

[0007] S1. Mix dilute calcium nitrate solution and nitric acid solution evenly in proportion to obtain a mixed solution;

[0008] S2. Ammonia solution is introduced into the mixture to carry out the reaction, and the calcium ammonium nitrate solution is obtained after the reaction is completed.

[0009] The flow rate of the dilute calcium nitrate solution is the main parameter, the flow rate of the nitric acid solution is adjusted according to the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is adjusted according to the flow rate of the nitric acid solution.

[0010] Furthermore, the mass ratio of calcium nitrate, nitric acid, and ammonia after decomposition is 45.6:3.5:1.

[0011] Furthermore, the flow rates of the dilute calcium nitrate solution, nitric acid solution, and ammonia solution are measured by a mass flow meter and controlled by a flow regulating valve.

[0012] Furthermore, the dilute calcium nitrate solution and the nitric acid solution are mixed in the primary mixing section of a multi-tube reactor.

[0013] Furthermore, the mixture of dilute calcium nitrate solution and nitric acid solution is reacted in the reaction section of a multi-tube reactor.

[0014] Furthermore, the mass percentage concentration of the ammonia water is 10-20%; more preferably, the mass percentage concentration of the ammonia water is 15%.

[0015] Furthermore, the integrated method for producing calcium ammonium nitrate solution also includes step S3, adjusting the pH value of the dilute calcium ammonium nitrate solution to a final pH value of 5-6.

[0016] Furthermore, the dilute ammonium calcium nitrate solution is pH-adjusted by adding acid in the final mixing section of the multi-tube reactor.

[0017] Furthermore, the mass percentage concentration of the nitric acid solution is 45-60%.

[0018] Furthermore, the method for preparing the dilute calcium nitrate solution includes reacting limestone and nitric acid in an acid hydrolysis tower to produce a dilute calcium nitrate solution, and then removing insoluble matter from the dilute calcium nitrate solution by passing it through a filter press to obtain the dilute calcium nitrate solution.

[0019] Compared with the prior art, the advantages of the present invention include:

[0020] This invention provides an integrated method for producing calcium ammonium nitrate solution. The method includes mixing filtrate with nitric acid solution, then introducing ammonia water, and reacting to obtain the dilute calcium ammonium nitrate solution. The entire process does not require the hazardous chemical ammonium nitrate solution, ensuring production safety and promoting the development of calcium ammonium nitrate production enterprises. Furthermore, the entire process uses the flow rate of the dilute calcium nitrate solution as the main parameter. The flow rate of the nitric acid solution is adjusted proportionally based on the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is also adjusted proportionally based on the flow rate of the nitric acid solution, allowing for better proportioning and producing a higher quality calcium ammonium nitrate solution. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0022] Figure 1 This is a schematic diagram of an integrated control system for producing calcium ammonium nitrate in a typical embodiment of the present invention;

[0023] The diagram is labeled as follows: 1. Tubular reactor; 2. First nitric acid tank; 3. Second nitric acid tank; 4. Ammonia tank; 5. Dilute calcium nitrate solution tank; 6. Mass flow meter; 7. Flow regulating valve; 8. Sampling cooler; 9. pH meter; 10. Nitric acid regulating valve. Detailed Implementation

[0024] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0025] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0026] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0027] One aspect of this invention provides a method for the integrated production of calcium ammonium nitrate solution, comprising the following steps:

[0028] S1. Mix dilute calcium nitrate solution and nitric acid solution with a mass percentage concentration of 45-60% in the primary mixing section of a multi-tube reactor in a certain proportion to obtain a mixed solution.

[0029] S2. In the reaction section of the multi-tube reactor, an ammonia solution with a mass percentage concentration of 10-20% is introduced into the mixture to carry out the reaction. After the reaction is completed, the calcium ammonium nitrate solution is obtained.

[0030] S3. The pH of the dilute calcium ammonium nitrate solution is adjusted in the final mixing section of the multi-tube reactor, and the final pH value is 5-6.

[0031] The flow rate of the dilute calcium nitrate solution is the main parameter, the flow rate of the nitric acid solution is adjusted according to the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is adjusted according to the flow rate of the nitric acid solution.

[0032] Preferably, the mass ratio of calcium nitrate, nitric acid, and ammonia after decomposition is 45.6:3.5:1.

[0033] Preferably, the flow rates of the dilute calcium nitrate solution, nitric acid solution, and ammonia solution are measured by a mass flow meter and controlled by a flow regulating valve.

[0034] Preferably, the ammonia solution has a mass percentage concentration of 15%.

[0035] Preferably, the method for preparing the dilute calcium nitrate solution includes reacting limestone and nitric acid in an acid hydrolysis tower to produce a dilute calcium nitrate solution, and then removing insoluble matter from the dilute calcium nitrate solution using a filter press to obtain the dilute calcium nitrate solution.

[0036] In practical implementation, the following systems can also be used for control operations.

[0037] like Figure 1 As shown, this embodiment of the invention provides an integrated control system for producing calcium ammonium nitrate, including a tubular reactor 1, a first nitric acid tank 2 containing nitric acid, a second nitric acid tank 3 containing nitric acid, an ammonia water tank 4 containing ammonia water, a dilute calcium nitrate solution tank 5 containing dilute calcium nitrate solution, and a control device. The outlets of the first nitric acid tank 2 and the dilute calcium nitrate solution tank 5 are respectively connected to the inlet of the tubular reactor 1.

[0038] The tubular reactor 1 includes a primary mixing section, a reaction section, and a final mixing section. The primary mixing section and the final mixing section are respectively located at both ends of the reaction section. The reaction section has a first inlet, and the final mixing section has a second inlet. The outlet of the ammonia tank 4 is connected to the first inlet of the reaction section, and the outlet of the second nitric acid tank 3 is connected to the second inlet of the final mixing section. In a specific implementation, the tubular reactor 1 is selected from the SK type multi-tube reactor 1.

[0039] The control device includes a flow control module and a pH control module. The flow control module is used to adjust the liquid discharge flow rate of the first nitric acid tank 2, the ammonia tank 4, and the dilute calcium nitrate solution tank 5. The pH control module is used to adjust the pH value of the liquid discharged from the final mixing section. A mass flow meter 6 and a flow regulating valve 7 are provided at the outlets of the first nitric acid tank 2, the ammonia tank 4, and the dilute calcium nitrate solution tank 5.

[0040] The pH control module includes a sampling cooler 8, a pH meter 9, and a nitric acid regulating valve 10, which is used to regulate the liquid discharge flow rate in the second nitric acid tank 3.

[0041] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0042] Example 1

[0043] This embodiment provides a batching method for integrated production of calcium ammonium nitrate solution, including the following steps:

[0044] S1. Mix dilute calcium nitrate solution and nitric acid solution with a mass percentage concentration of 45% in the primary mixing section of a multi-tube reactor in a certain proportion to obtain a mixed solution.

[0045] S2. In the reaction section of the multi-tube reactor, an ammonia solution with a mass percentage concentration of 10% is introduced into the mixture to carry out the reaction. After the reaction is completed, the calcium ammonium nitrate solution is obtained.

[0046] S3. The pH of the dilute calcium ammonium nitrate solution is adjusted in the final mixing section of the multi-tube reactor, and the final pH value is 5.

[0047] The flow rate of the dilute calcium nitrate solution is the primary parameter. The flow rate of the nitric acid solution is adjusted according to the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is adjusted according to the flow rate of the nitric acid solution. The mass ratio of calcium nitrate, nitric acid, and ammonia solution after 100% conversion is 45.6:3.5:1.

[0048] The method for preparing the dilute calcium nitrate solution includes reacting limestone and nitric acid in an acid hydrolysis tower to produce a dilute calcium nitrate solution, and then removing insoluble matter from the dilute calcium nitrate solution using a filter press to obtain the dilute calcium nitrate solution.

[0049] Example 2

[0050] This embodiment provides a batching method for integrated production of calcium ammonium nitrate solution, including the following steps:

[0051] S1. Mix dilute calcium nitrate solution and nitric acid solution with a mass percentage concentration of 60% in the primary mixing section of a multi-tube reactor in a certain proportion to obtain a mixed solution.

[0052] S2. In the reaction section of the multi-tube reactor, an ammonia solution with a mass percentage concentration of 20% is introduced into the mixture to carry out the reaction. After the reaction is completed, the calcium ammonium nitrate solution is obtained.

[0053] S3. The pH of the dilute calcium ammonium nitrate solution is adjusted in the final mixing section of the multi-tube reactor, and the final pH value is 5-6.

[0054] The flow rate of the dilute calcium nitrate solution is the primary parameter. The flow rate of the nitric acid solution is adjusted according to the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is adjusted according to the flow rate of the nitric acid solution. The mass ratio of calcium nitrate, nitric acid, and ammonia solution after 100% conversion is 45.6:3.5:1.

[0055] The method for preparing the dilute calcium nitrate solution includes reacting limestone and nitric acid in an acid hydrolysis tower to produce a dilute calcium nitrate solution, and then removing insoluble matter from the dilute calcium nitrate solution using a filter press to obtain the dilute calcium nitrate solution.

[0056] Example 3

[0057] This embodiment provides a batching method for integrated production of calcium ammonium nitrate solution, including the following steps:

[0058] S1. Mix dilute calcium nitrate solution and nitric acid solution with a mass percentage concentration of 52.5% in the primary mixing section of a multi-tube reactor in a certain proportion to obtain a mixed solution.

[0059] S2. In the reaction section of the multi-tube reactor, an ammonia solution with a mass percentage concentration of 15% is introduced into the mixture to carry out the reaction. After the reaction is completed, the calcium ammonium nitrate solution is obtained.

[0060] S3. The pH of the dilute calcium ammonium nitrate solution is adjusted in the final mixing section of the multi-tube reactor, and the final pH value is 5.5.

[0061] The flow rate of the dilute calcium nitrate solution is the primary parameter. The flow rate of the nitric acid solution is adjusted according to the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is adjusted according to the flow rate of the nitric acid solution. The mass ratio of calcium nitrate, nitric acid, and ammonia solution after 100% conversion is 45.6:3.5:1.

[0062] The method for preparing the dilute calcium nitrate solution includes reacting limestone and nitric acid in an acid hydrolysis tower to produce a dilute calcium nitrate solution, and then removing insoluble matter from the dilute calcium nitrate solution using a filter press to obtain the dilute calcium nitrate solution.

[0063] The above descriptions are merely some embodiments of the present invention. It should be noted that those skilled in the art can make other modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A batching method for integrated production of ammonium calcium nitrate solution, characterized in that, Includes the following steps: S1. Mix dilute calcium nitrate solution and nitric acid solution evenly in proportion to obtain a mixed solution; S2. Ammonia solution is introduced into the mixture to carry out the reaction, and the calcium ammonium nitrate solution is obtained after the reaction is completed. Wherein, the flow rate of the dilute calcium nitrate solution is the main parameter, the flow rate of the nitric acid solution is adjusted according to the flow rate of the dilute calcium nitrate solution, and the flow rate of the ammonia solution is adjusted according to the flow rate of the nitric acid solution, including: The mass ratio of calcium nitrate, nitric acid, and ammonia, after decomposition, is 45.6:3.5:

1. The dilute calcium nitrate solution and the nitric acid solution are mixed in the primary mixing section of a multi-tube reactor; The mixture of dilute calcium nitrate solution and nitric acid solution is reacted in the reaction section of a multi-tube reactor.

2. The batching method for integrated production of calcium ammonium nitrate solution according to claim 1, characterized in that: The flow rates of the dilute calcium nitrate solution, nitric acid solution, and ammonia solution are measured by a mass flow meter and controlled by a flow regulating valve.

3. The batching method for integrated production of calcium ammonium nitrate solution according to claim 1, characterized in that: The mass percentage concentration of the ammonia water is 10-20%.

4. The batching method for integrated production of calcium ammonium nitrate solution according to claim 1, characterized in that: It also includes step S3, adjusting the pH value of the ammonium calcium nitrate solution, with the final pH value being 5-6.

5. The batching method for integrated production of calcium ammonium nitrate solution according to claim 4, characterized in that: The ammonium calcium nitrate solution is pH adjusted by adding acid in the final mixing section of the multi-tube reactor.

6. The batching method for integrated production of calcium ammonium nitrate solution according to claim 1, characterized in that: The mass percentage concentration of the nitric acid solution is 45-60%.

7. The batching method for integrated production of calcium ammonium nitrate solution according to claim 1, characterized in that: The method for preparing the dilute calcium nitrate solution includes reacting limestone and nitric acid in an acid hydrolysis tower to produce a dilute calcium nitrate solution, and then removing insoluble matter from the dilute calcium nitrate solution by passing it through a filter press to obtain the dilute calcium nitrate solution.

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