Device for preparing calcium magnesium ammonium nitrate fertilizer by decomposing phosphate tailings with nitric acid

Abstract

The utility model discloses a device for preparing ammonium calcium magnesium nitrate fertilizer by decomposing phosphate tailings with nitric acid, which comprises a dissolving tank, the dissolving tank is communicated with a filter press through a pipeline, and a liquid discharge port of the filter press is communicated with a buffer tank and a neutralizing tank through pipelines. The neutralizing tank is sequentially communicated with the first-stage energy efficiency heater, the second-stage energy efficiency heater and the third-stage energy efficiency heater through pipelines, the third-stage energy efficiency heater is communicated with the upper part of the granulation tower through a pipeline, the neutralizing tank is provided with an ammonia water inlet pipe, a material inlet of the dissolving tank is communicated with a phosphate tailing conveying mechanism, and the dissolving tank is also provided with a nitric acid inlet pipe. According to the utility model, the aims of treating the phosphate tailings and comprehensively utilizing resources to produce the calcium magnesium nitrate compound fertilizer can be fulfilled, the problem of treating the phosphate tailings is solved, meanwhile, the resource utilization of by-products calcium and magnesium can be realized, and new economic benefits are realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of compound fertilizer production for agriculture, in particular to a device for preparing calcium-magnesium-ammonium nitrate fertilizer by decomposing phosphorus tailings with nitric acid. BACKGROUND

[0002] Phosphorus ore is an important raw material for the fertilizer - phosphate fertilizer needed in global agricultural production, is an important guarantee for global food production, and is also a raw material for fine chemical product production. With the continuous development of phosphorus ore resources at present, the production capacity of wet-process phosphoric acid is continuously expanded, and the output of phosphorus tailings is also continuously accumulated. After flotation, 150-200 thousand tons of phosphorus tailings can be produced from every 1 million tons of phosphorus ore, which has a great impact on safety and environment. It is of great significance to study the use of nitric acid to decompose phosphorus tailings, mainly to release nitric acid production capacity, consume phosphorus tailings, reduce the pollution of phosphorus tailings to the environment, and improve the utilization rate of phosphorus tailings. CONTENT OF THE UTILITY MODEL

[0003] The main purpose of the utility model is to provide a device for preparing calcium-magnesium-ammonium nitrate fertilizer by decomposing phosphorus tailings with nitric acid. After adopting nitric acid acidification reaction, solid-liquid separation of a filter press, ammonia water neutralization, concentration, granulation and other processes, calcium-magnesium-ammonium nitrate compound fertilizer is obtained. Phosphorus tailings, nitric acid and ammonia are used as raw materials to prepare calcium-magnesium-ammonium nitrate fertilizer products. At the same time, through the recycling of excess ammonia gas, high-value utilization and clean production of phosphorus chemical solid waste are realized. The recycling economy concept of "reduction, recycling and reuse" is fully embodied, the resource utilization rate is maximized, and the purpose of green chemical development is achieved.

[0004] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0005] A device for preparing calcium-magnesium-ammonium nitrate fertilizer by decomposing phosphorus tailings with nitric acid, comprising a dissolving tank, the dissolving tank is communicated with a filter press through a pipeline, the liquid discharge port of the filter press is communicated with a buffer tank and a neutralization tank through a pipeline, the neutralization tank is communicated with a first energy efficiency heater, a second energy efficiency heater and a third energy efficiency heater in sequence through a pipeline, the third energy efficiency heater is communicated with the upper part of a prilling tower through a pipeline, the neutralization tank is provided with an ammonia water inlet pipe, the inlet of the dissolving tank is communicated with a phosphorus tailings conveying mechanism, and the dissolving tank is also provided with a nitric acid inlet pipe.

[0006] Preferably, a discharge pump is arranged on the pipeline communicated between the dissolving tank and the filter press, a buffer liquid conveying pump is arranged on the pipeline communicated between the buffer tank and the neutralization tank, a neutralization liquid conveying pump is arranged on the pipeline communicated between the neutralization tank and the first energy efficiency heater, and a prilling conveying pump is arranged on the pipeline communicated between the third energy efficiency heater and the prilling tower.

[0007] Preferably, pH detectors are arranged on the dissolving tank, the buffer tank and the neutralization tank, and stirring paddles are arranged.

[0008] Preferably, the dissolving tank, buffer tank and neutralizing tank are made of 2205 stainless steel.

[0009] Preferably, the filter press is a plate-and-frame filter press, the metal material of which is 2205 stainless steel, the non-metal part of which is PP, and the filter cloth of which is PP3927 large chemical fiber cloth, and the filtering precision of which is 0.5 microns.

[0010] Preferably, the phosphorus tailing conveying mechanism is a belt conveyor.

[0011] Preferably,

[0012] The utility model has the following beneficial effects:

[0013] 1. The device can realize the treatment of phosphorus tailings and the comprehensive utilization of resources to produce calcium magnesium ammonium nitrate compound fertilizer, which not only solves the problem of phosphorus tailings treatment, but also realizes the resource utilization of calcium magnesium in phosphorus tailings and achieves new economic benefits.

[0014] 2. The continuous flow reaction device and the filtering device are adopted to realize the standard treatment of phosphorus tailings and obtain by-product calcium magnesium ammonium nitrate compound fertilizer, and the economic benefit is good.

[0015] 3. The device adopts corrosion-resistant special materials, which can resist the corrosion of materials to the greatest extent and realize long-period stable operation of the device. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic view of the utility model.

[0017] Among them: dissolving tank 1, phosphorus tailing conveying mechanism 1-1, nitric acid feeding pipe 1-2, filter press 2, buffer tank 3, neutralizing tank 4, ammonia water inlet pipe 4-1, primary energy-efficient heater 5, secondary energy-efficient heater 6, tertiary energy-efficient heater 7, granulation tower 8, discharge pump 9, buffer solution conveying pump 10, neutralizing liquid conveying pump 11, granulation conveying pump 12. DETAILED DESCRIPTION

[0018] The preferred embodiments of the utility model will be described below in conjunction with the drawings, and it should be understood that the preferred embodiments described here are only used to illustrate and explain the utility model, and are not used to limit the utility model.

[0019] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0020] Example 1

[0021] The device for preparing calcium magnesium nitrate ammonium fertilizer from nitric acid decomposed phosphorus tailings comprises a dissolving tank 1, the dissolving tank 1 is communicated with a filter press 2 through a pipeline, a liquid outlet of the filter press 2 is communicated with a buffer tank 3 and a neutralizing tank 4 through pipelines, the neutralizing tank 4 is sequentially communicated with a first energy efficiency heater 5, a second energy efficiency heater 6 and a third energy efficiency heater 7 through pipelines, the third energy efficiency heater 7 is communicated with an upper portion of a prilling tower 8 through a pipeline, the neutralizing tank 4 is provided with an ammonia water inlet pipe 4-1, a feed inlet of the dissolving tank 1 is communicated with a phosphorus tailings conveying mechanism 1-1, and the dissolving tank 1 is further provided with a nitric acid feed pipe 1-2.

[0022] Preferably, a discharge pump 9 is arranged on the pipeline communicated between the dissolving tank 1 and the filter press 2, a buffer liquid conveying pump 10 is arranged on the pipeline communicated between the buffer tank 3 and the neutralizing tank 4, a neutralizing liquid conveying pump 11 is arranged on the pipeline communicated between the neutralizing tank 4 and the first energy efficiency heater 5, and a prilling conveying pump 12 is arranged on the pipeline communicated between the third energy efficiency heater 7 and the prilling tower 8.

[0023] Preferably, pH detectors are arranged on the dissolving tank 1, the buffer tank 3 and the neutralizing tank 4, and stirring paddles are arranged.

[0024] Preferably, the material of the dissolving tank 1, the buffer tank 3 and the neutralizing tank 4 is 2205 stainless steel.

[0025] Preferably, the filter press 2 is a plate-and-frame filter press, the metal material of the filter press 2 is 2205 stainless steel, the non-metal part of the filter press 2 is PP, the filter cloth of the filter press 2 is PP3927 large chemical fiber cloth, and the filtration precision of the filter press 2 is 0.5 microns.

[0026] Preferably, the phosphorus tailings conveying mechanism 1-1 is a belt conveyor.

[0027] The dissolving tank is a tank with a stirring paddle, is provided with an online pH detector and is remotely transmitted by DCS, mainly mixes and reacts the phosphorus tailings and the nitric acid, and the material of the dissolving tank is 2205 stainless steel.

[0028] The filter press is a plate-and-frame filter press, mainly separates the solid and liquid of the reacted material, obtains the unreacted solid slag with a water content of about 20%, the metal material of the filter press is 2205 stainless steel, the non-metal part of the filter press is PP, the filter cloth of the filter press is PP3927 large chemical fiber cloth, and the filtration precision of the filter press is 0.5 microns.

[0029] The buffer tank is a tank with a stirring paddle, is provided with an online pH detector and is remotely transmitted by DCS, mainly receives the filtrate of the filter press, and the material of the buffer tank is 2205 stainless steel.

[0030] The neutralizing tank is a tank with a stirring paddle, is provided with an online pH detector and is remotely transmitted by DCS, mainly neutralizes the acidic filtrate after reaction and the ammonia water, and the material of the neutralizing tank is 2205 stainless steel.

[0031] The three-effect heating system is a steam heating type three-effect heating concentration system, which mainly concentrates the slurry in the neutralizing tank to obtain calcium magnesium nitrate ammonium crystal slurry with a solid content of about 60%.

[0032] The prilling tower is a spray prilling type hot air drying tower, which mainly prills the calcium magnesium nitrate ammonium crystal slurry and dries it to obtain calcium magnesium nitrate ammonium compound fertilizer products with a water content of about 0.5%.

[0033] The whole device accurately controls the pH of the reaction, each washing tank is equipped with an on-line pH detector, which can accurately display the pH, so that the purpose of accurate control is achieved, and the device can be stably operated for a long period.

[0034] After nitric acid acidification reaction, solid-liquid separation by a filter press, ammonia neutralization, concentration, prilling and other processes, calcium magnesium nitrate ammonium compound fertilizer is obtained.

[0035] The above embodiments are only preferred technical solutions of the present application, and should not be regarded as limiting the present application. The embodiments in the application and the features in the embodiments can be combined with each other as long as they do not conflict. The protection scope of the present application should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features recorded in the claims. That is, the equivalent replacement improvement within this range is also within the protection scope of the present application.

Claims

1. A device for preparing calcium magnesium ammonium nitrate fertilizer from nitric acid decomposed phosphorus tailings, comprising a dissolving tank (1), characterized in that, The dissolving tank (1) is communicated with the filter press (2) through a pipeline, the liquid outlet of the filter press (2) is communicated with the buffer tank (3) and the neutralizing tank (4) through pipelines, the neutralizing tank (4) is communicated with the first energy efficiency heater (5), the second energy efficiency heater (6) and the third energy efficiency heater (7) in sequence through pipelines, the third energy efficiency heater (7) is communicated with the upper part of the prilling tower (8) through a pipeline, the neutralizing tank (4) is provided with an ammonia water inlet pipe (4-1), the inlet of the dissolving tank (1) is communicated with the phosphate tailings conveying mechanism (1-1), and the dissolving tank (1) is further provided with a nitric acid inlet pipe (1-2).

2. The device for preparing calcium magnesium ammonium nitrate fertilizer from nitric acid decomposed phosphorus tailings according to claim 1, characterized in that: A discharge pump (9) is arranged on the communication pipeline between the dissolving tank (1) and the filter press (2), a buffer solution conveying pump (10) is arranged on the communication pipeline between the buffer tank (3) and the neutralizing tank (4), a neutralizing liquid conveying pump (11) is arranged on the communication pipeline between the neutralizing tank (4) and the first energy efficiency heater (5), and a prilling conveying pump (12) is arranged on the communication pipeline between the third energy efficiency heater (7) and the prilling tower (8).

3. The device for preparing calcium magnesium ammonium nitrate fertilizer from nitric acid decomposed phosphorus tailings according to claim 1, characterized in that: The dissolving tank (1), the buffer tank (3) and the neutralizing tank (4) are provided with pH detectors and stirring paddles.

4. The device for preparing calcium magnesium ammonium nitrate fertilizer from nitric acid decomposed phosphorus tailings according to claim 1, characterized in that: The dissolving tank (1), the buffer tank (3) and the neutralizing tank (4) are made of 2205 stainless steel.

5. The device for preparing calcium magnesium ammonium nitrate fertilizer from nitric acid decomposed phosphorus tailings according to claim 1, characterized in that: The filter press (2) is a plate-and-frame filter press, the metal material thereof is 2205 stainless steel, the non-metal part is PP, and the filter cloth has a filtering precision of 0.4-0.6 microns.

6. The device for preparing calcium magnesium ammonium nitrate fertilizer from nitric acid decomposed phosphorus tailings according to claim 1, characterized in that: The phosphate tailings conveying mechanism (1-1) is a belt conveyor.

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