Nano calcium carbonate preparation system

Abstract

The utility model relates to the technical field of nano calcium carbonate preparation, in particular to a nano calcium carbonate preparation system which comprises a hydrolysis tank, a first conveying pipe is communicated with the side lower part of the hydrolysis tank, a first surface filter is communicated with the first conveying pipe, and an upper outlet of the first surface filter is communicated with a buffer tank through a pipeline; the buffer tank is communicated with a second conveying pipe, the second conveying pipe is communicated with an inlet of a Jinyu reactor, an outlet in the bottom surface of the Jinyu reactor is communicated with a second surface filter through a pipeline, and an outlet in the upper part of the second surface filter is communicated with a buffer tank through a pipeline. According to the nano calcium carbonate preparation system, after lime nitrogen is hydrolyzed, water-insoluble impurities are filtered out firstly, the whiteness of a nano calcium carbonate product is guaranteed, meanwhile, only substances such as graphite are intercepted during filtering, Ca < 2 + > reacts with a cyanamide product and remains in the system in the form of basic salt, and loss is avoided. And the filtered graphite waste residue can be recycled.

Description

Technical Field

[0001] The utility model relates to the technical field of nano calcium carbonate preparation, in particular to a nano calcium carbonate preparation system. Background Art

[0002] Nano calcium carbonate refers to calcium carbonate products with a particle size of 0 to 100 nm, including ultrafine calcium carbonate and ultrafine calcium carbonate. Compared with ordinary calcium carbonate products, nano calcium carbonate has the characteristics of fine particles, high surface activation rate, and high whiteness. It is one of the nano materials that can be industrially produced and applied at present, and can replace expensive white carbon black and titanium dioxide.

[0003] The existing preparation of nano calcium carbonate is mainly based on double decomposition and carbonization, which are complex processes, have high requirements on equipment, and are difficult to select crystal control agents. Lime nitrogen is mainly used in the fertilizer industry. It contains impurities such as carbon, but is slightly soluble in water and is prone to produce toxic and harmful byproducts. Lime nitrogen is usually used in the industry to prepare cyanamide, but there is a large amount of black waste residue accumulation and waste.

[0004] Therefore, developing a nano calcium carbonate preparation system can improve reaction efficiency, save costs and space while rationally utilizing waste liquid and waste residue in the process. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] The utility model provides a nano calcium carbonate preparation system, comprising a hydrolysis tank, wherein the lower part of the hydrolysis tank side is connected with a first delivery pipe, the first delivery pipe is connected with a first surface filter, the upper outlet of the first surface filter is connected with a buffer tank through a pipeline, the buffer tank is connected with a second delivery pipe, the second delivery pipe is connected with an inlet of a Jinyu reactor, the bottom outlet of the Jinyu reactor is connected with the second surface filter through a pipeline, and the upper outlet of the second surface filter is connected with the buffer tank through a pipeline.

[0007] As a preferred technical solution of the utility model, a slag outlet is provided on the bottom surface of the first surface filter, a valve is installed on the slag outlet, the slag outlet is connected to a slag tank through a pipeline, and the slag tank is located below the first surface filter.

[0008] As a preferred technical solution of the utility model, a discharge port is provided on the bottom surface of the second surface filter, a valve is installed on the discharge port, the discharge port is connected to a calcium carbonate storage tank through a pipeline, and the calcium carbonate storage tank is located below the second surface filter.

[0009] As a preferred technical solution of the utility model, the lower part of the side of the calcium carbonate storage tank is connected to a third delivery pipe, and the third delivery pipe is connected to a plate and frame filter press.

[0010] As a preferred technical solution of the utility model, the first delivery pipe, the second delivery pipe and the third delivery pipe are all equipped with liquid pumps.

[0011] As a preferred technical solution of the utility model, the outlet height of the first surface filter is greater than the inlet height of the buffer tank; the bottom outlet height of the Jinyu reactor is greater than the inlet height of the second surface filter; the outlet height of the second surface filter is greater than the inlet height of the buffer tank.

[0012] As a preferred technical solution of the utility model, a carbon dioxide inlet is provided on the side of the Jinyu reactor, and a PVP crystal form control agent inlet is provided on the top surface of the Jinyu reactor.

[0013] The beneficial effects of the utility model are:

[0014] 1. This kind of nano calcium carbonate preparation system, the first surface filter and the second surface filter are automatic backwashing surface filters, which adopt flexible filtering anti-corrosion materials, use pressure difference and its own filtered clear liquid to backwash the filter membrane, and no additional air source or water source is required; the system starts and closes with the company's patented air-controlled flexible valve, the pipe and valve have the same diameter, open and close quickly, and can quickly form a pressure difference for backwashing.

[0015] 2. This nano calcium carbonate preparation system, Jinyu reactor can make gas and liquid flow, collide and mix continuously in elastic micro-channels, improve the overall reaction rate and material utilization, reduce raw material costs, replace traditional reaction pools and reaction tanks, and realize industrial automatic operation in conjunction with automatic backwashing surface filters.

[0016] 3. This kind of nano calcium carbonate preparation system has an automatic backwashing surface filter, which is easy to clean and maintain, and reduces manpower and material costs. The Jinyu filter is more responsive and efficient than ordinary stirred reaction tanks and other devices.

[0017] 4. This nano calcium carbonate preparation system first filters out water-insoluble impurities after lime nitrogen hydrolysis to ensure the whiteness of the nano calcium carbonate product. At the same time, only graphite and other substances are retained during filtration. 2+ It reacts with cyanamide products and remains in the system in the form of basic salts without loss. The filtered graphite waste can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 This is a schematic structural diagram of a nano calcium carbonate preparation system of the utility model;

[0020] Figure 2 This is a schematic diagram of the process of a nano calcium carbonate preparation system of the utility model;

[0021] In the figure: 1. hydrolysis tank; 2. first delivery pipe; 3. first surface filter; 4. buffer tank; 5. second delivery pipe; 6. Jinyu reactor; 7. slag tank; 8. second surface filter; 9. buffer tank; 10. calcium carbonate storage tank; 11. third delivery pipe; 12. plate and frame filter press. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0023] Example: Figure 1-Figure 2 As shown, a nano calcium carbonate preparation system includes a hydrolysis tank 1, a first delivery pipe 2 is connected to the lower part of the hydrolysis tank 1, the first delivery pipe 2 is connected to the first surface filter 3, the upper outlet of the first surface filter 3 is connected to the buffer tank 4 through a pipeline, the buffer tank 4 is connected to the second delivery pipe 5, the second delivery pipe 5 is connected to the inlet of the Jinyu reactor 6, the bottom outlet of the Jinyu reactor 6 is connected to the second surface filter 8 through a pipeline, and the upper outlet of the second surface filter 8 is connected to the buffer tank 9 through a pipeline.

[0024] A slag outlet is provided on the bottom surface of the first surface filter 3 , a valve is installed on the slag outlet, the slag outlet is connected to a slag tank 7 through a pipeline, and the slag tank 7 is located below the first surface filter 3 .

[0025] A discharge port is provided on the bottom surface of the second surface filter 8 , a valve is installed on the discharge port, the discharge port is connected to a calcium carbonate storage tank 10 through a pipeline, and the calcium carbonate storage tank 10 is located below the second surface filter 8 .

[0026] A third delivery pipe 11 is connected to the lower side of the calcium carbonate storage tank 10 , and the third delivery pipe 11 is connected to a plate and frame filter press 12 .

[0027] Liquid pumps are installed on the first delivery pipe 2 , the second delivery pipe 5 and the third delivery pipe 11 .

[0028] The outlet height of the first surface filter 3 is greater than the inlet height of the buffer tank 4; the bottom outlet height of the Jinyu reactor 6 is greater than the inlet height of the second surface filter 8; the outlet height of the second surface filter 8 is greater than the inlet height of the buffer tank 9.

[0029] A carbon dioxide inlet is provided on the side of the Jinyu reactor 6 , and a PVP crystal form control agent inlet is provided on the top surface of the Jinyu reactor 6 .

[0030] Working principle: Before using this nano calcium carbonate preparation system, first check whether the nano calcium carbonate preparation system can be used normally. A stirrer is installed inside the hydrolysis tank 1 to stir lime nitrogen and water to speed up the mixing speed between the two;

[0031] The first surface filter 3 and the second surface filter 8 are automatic backwashing surface filters, which are made of flexible filtering and corrosion-resistant materials, and the Jinyu reactor 6 is a microchannel reactor;

[0032] Hydrolysis stage: 10kg of lime nitrogen and 20L of water are stirred and dissolved in the hydrolysis tank 1, and the hydrolyzed mixture is pumped into the first surface filter 3 through the liquid pump, and the waste residue after filtration is collected in the slag tank 7, and the filtrate enters the buffer tank 4 for storage;

[0033] Crystal form control stage: The filtrate is pumped from the buffer tank 4 into the Jinyu reactor 6 through a liquid pump, and a certain amount of PVP crystal form control agent is added, and 0.4MpaCO2 is introduced for reaction. The reaction temperature is below 55°C, and the pH is controlled at about 8-10;

[0034] Secondary filtration stage; the fully reacted mixed solution enters the second surface filter 8 through the Jinyu reactor 6 for filtration, the filtrate is collected in the buffer tank 9 for the preparation of cyanamide products, and the slurry is collected in the calcium carbonate storage tank 10;

[0035] Drying stage: the nano calcium carbonate slurry is pumped into the plate and frame filter press 12 by a liquid pump, and the product after filtration is collected through the outlet and dried to obtain the nano calcium carbonate product;

[0036] The chemical reactions involved in the above process are:

[0037] CaCN2+H2O→Ca(HCN2)2+Ca(OH)2↓

[0038] Ca(HCN2)2+H2O→2H2CN2+Ca(OH)2↓

[0039] Ca(HCN2)2+H2O+CO2→2H2CN2+CaCO3↓.

[0040] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A nano calcium carbonate preparation system, comprising a hydrolysis tank (1), characterized in that: The lower part of the hydrolysis tank (1) is connected to a first delivery pipe (2), the first delivery pipe (2) is connected to a first surface filter (3), the upper outlet of the first surface filter (3) is connected to a buffer tank (4) through a pipeline, the buffer tank (4) is connected to a second delivery pipe (5), the second delivery pipe (5) is connected to the inlet of the Jinyu reactor (6), the bottom outlet of the Jinyu reactor (6) is connected to a second surface filter (8) through a pipeline, and the upper outlet of the second surface filter (8) is connected to a buffer tank (9) through a pipeline.

2. A nano calcium carbonate preparation system according to claim 1, characterized in that, The bottom surface of the first surface filter (3) is provided with a slag outlet, a valve is installed on the slag outlet, the slag outlet is connected to a slag tank (7) through a pipeline, and the slag tank (7) is located below the first surface filter (3).

3. A nano calcium carbonate preparation system according to claim 1, characterized in that, The bottom surface of the second surface filter (8) is provided with a discharge port, a valve is installed on the discharge port, the discharge port is connected to a calcium carbonate storage tank (10) through a pipeline, and the calcium carbonate storage tank (10) is located below the second surface filter (8).

4. A nano calcium carbonate preparation system according to claim 3, characterized in that, The lower part of the side of the calcium carbonate storage tank (10) is connected to a third delivery pipe (11), and the third delivery pipe (11) is connected to a plate and frame filter press (12).

5. A nano calcium carbonate preparation system according to claim 4, characterized in that, The first delivery pipe (2), the second delivery pipe (5) and the third delivery pipe (11) are all equipped with liquid pumps.

6. A nano calcium carbonate preparation system according to claim 1, characterized in that, The outlet height of the first surface filter (3) is greater than the inlet height of the buffer tank (4); the bottom outlet height of the Jinyu reactor (6) is greater than the inlet height of the second surface filter (8); the outlet height of the second surface filter (8) is greater than the inlet height of the buffer tank (9).

7. A nano calcium carbonate preparation system according to claim 1, characterized in that, A carbon dioxide inlet is provided on the side of the Jinyu reactor (6), and a PVP crystal form control agent inlet is provided on the top surface of the Jinyu reactor (6).

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