Device for preparing active nano calcium carbonate from ardealite

Abstract

The device comprises a phase transfer reaction kettle, a carbonization reaction kettle, a modification reaction kettle, a filter pressing mechanism and a vacuum pump, the bottoms of the phase transfer reaction kettle, the carbonization reaction kettle and the modification reaction kettle are all provided with discharge ports, and the tops of the phase transfer reaction kettle, the carbonization reaction kettle and the modification reaction kettle are all provided with feed ports, water inlets and vacuum gas path interfaces; each discharge port is connected with an inlet of the filter pressing mechanism, each feed port is connected with an outlet of the filter pressing mechanism, each water inlet is connected with a water source, and each vacuum gas path interface is connected with a vacuum pump. By designing the three independent reaction kettles, the ardealite is subjected to phase transfer reaction, carbonization reaction and modification reaction respectively, so that a final product with higher purity can be obtained, impurities do not need to be removed by adopting strong acid leaching, the process condition is mild, and the equipment requirement is low.

Description

Technical Field

[0001] The utility model relates to the technical field of phosphogypsum, in particular to a device for preparing active nano calcium carbonate from phosphogypsum. Background Art

[0002] Phosphogypsum is a solid waste residue produced in the wet phosphoric acid process, and its main component is CaSO 4 ·2H 2 O, its main impurity is calcium sulfate. The storage of phosphogypsum not only occupies limited land resources and causes great damage to the environment, but also causes a waste of calcium and sulfur resources.

[0003] In order to recycle phosphogypsum, there is a method of using phosphogypsum to prepare nano-CaCO 3 The method of nano-CaCO 3 It is an inorganic nanomaterial developed at the end of the 20th century. Due to its unique nano properties, it is different from ordinary CaCO 3 In comparison, it exhibits more superior physical or chemical properties in terms of electricity, optics and mechanics, thus realizing the recycling of phosphogypsum.

[0004] At present, light / nano CaCO is prepared from phosphogypsum 3 The more mature route is the "two-step carbonization method" (technical route such as Figure 1 As shown). First, the phosphogypsum needs to be carbonized and precipitated to obtain crude calcium carbonate, and then the calcium carbonate is leached with hydrochloric acid to form a calcium chloride solution, which is then filtered to remove insoluble impurities in the original phosphogypsum, and finally secondary carbonization is performed to prepare calcium carbonate.

[0005] However, this process has the following problems: 1. Phosphogypsum forms a filter cake (which mainly contains the desired substance calcium carbonate) through carbonization filtration, but the insoluble impurities in the phosphogypsum, namely calcium sulfate, also enter the filter cake. In order to remove the impurities, acid leaching is required to extract the calcium carbonate. However, in the process of acid leaching and dissolution, not only is the process long, but the strong acid has high requirements on equipment during production, and the production cost increases; 2. In order to further improve the purity of the product, the process requires "secondary carbonization", the process is long, and industrial-scale production is relatively difficult.

[0006] In view of the above shortcomings, the Chinese patent application "A process for preparing active nano-calcium carbonate from phosphogypsum and its application" (CN116903017A) discloses an improved process for preparing active nano-calcium carbonate from phosphogypsum. It does not require a two-step process, simplifies the process route, does not require strong acid leaching to remove impurities, has mild process conditions and low equipment requirements. In order to meet the requirements of the process, a device for preparing active nano-calcium carbonate from phosphogypsum has been designed to facilitate subsequent implementation and production. Utility Model Content

[0007] The purpose of the utility model is to provide a device for preparing active nano calcium carbonate from phosphogypsum, by using a phase transfer reactor as a reaction site for a phase transfer agent and phosphogypsum, extracting calcium ions from the phosphogypsum, and then carrying out subsequent reactions in a carbonization reactor and a modification reactor, which not only improves the utilization rate of the phosphogypsum, but also can produce modified calcium carbonate with higher purity.

[0008] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0009] The utility model discloses a device for preparing active nano calcium carbonate from phosphogypsum, comprising a phase transfer reactor, a carbonization reactor, a modification reactor, a filter press mechanism and a vacuum pump, wherein: the phase transfer reactor, the carbonization reactor and the modification reactor are all provided with a discharge port at the bottom, and a feed port, a water inlet and a vacuum air path interface at the top; each discharge port is connected to the inlet of the filter press mechanism, each feed port is connected to the outlet of the filter press mechanism, each water inlet is connected to a water source, and each vacuum air path interface is connected to the vacuum pump.

[0010] A further solution: the discharge port is connected to the filter press mechanism via a pneumatic diaphragm pump.

[0011] A further solution: the feed port is connected to the filter press mechanism via a conveyor belt.

[0012] A further solution: a gas mixing mechanism is also connected to the bottom of the carbonization reactor, and the gas mixing mechanism includes a gas mixing tank, a carbon dioxide gas source connected to the gas mixing tank, and an air source.

[0013] A further solution: the filter press mechanism comprises a first filter press and a second filter press, the first filter press is connected to the carbonization reactor and the modification reactor, and the second filter press is connected to the phase transfer reactor.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model designs three independent reaction kettles to allow the phosphogypsum to undergo phase transfer reaction, carbonization reaction and modification reaction respectively, so as to obtain a final product with higher purity, without the need to use "strong acid leaching" to remove impurities, with mild process conditions and low equipment requirements.

[0016] The inlet of each reaction kettle is connected to the filter press mechanism through a pneumatic diaphragm pump, and the outlet is connected through a conveyor belt, which is convenient for the transfer or circulation of reaction materials at different stages, and the transportation route is relatively simplified, which reduces costs and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] In the figure: 1-phase transfer reactor, 2-carbonization reactor, 3-modification reactor, 4-filter press mechanism, 5-vacuum pump, 6-discharge port, 7-feed port, 8-water inlet, 9-vacuum air path interface, 10-water source, 11-gas mixing mechanism, 12-pneumatic diaphragm pump, 13-first filter press, 14-second filter press. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] In the description of the present utility model, it should be noted that the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0021] See also Figure 1 In this embodiment, a device for preparing active nano-calcium carbonate from phosphogypsum includes a phase transfer reactor 1, a carbonization reactor 2, a modification reactor 3, a filter press mechanism 4 and a vacuum pump 5, wherein: the phase transfer reactor 1, the carbonization reactor 2 and the modification reactor 3 are each provided with a discharge port 6 at the bottom, and a feed port 7, a water inlet 8 and a vacuum air path interface 9 at the top; each discharge port 6 is connected to the inlet of the filter press mechanism 4, each feed port 7 is connected to the outlet of the filter press mechanism 4, each water inlet 8 is connected to a water source 10, and each vacuum air path interface 9 is connected to the vacuum pump 5.

[0022] Furthermore, the discharge port 6 is connected to the filter press mechanism 4 via a pneumatic diaphragm pump 12 .

[0023] Furthermore, the feed port 7 is connected to the filter press mechanism 4 via a conveyor belt.

[0024] Furthermore, a gas mixing mechanism 11 is connected to the bottom of the carbonization reactor 2. The gas mixing mechanism 11 includes a gas mixing tank, a carbon dioxide gas source connected to the gas mixing tank, and an air source.

[0025] Furthermore, the filter press mechanism 4 includes a first filter press 13 and a second filter press 14 . The first filter press 13 is connected to the carbonization reactor 2 and the modification reactor 3 , and the second filter press 14 is connected to the phase transfer reactor 1 .

[0026] The operating principle of the utility model is as follows: water is passed through the water inlet 8 of the phase transfer reactor 1, and the phosphogypsum enters the reactor through the feed inlet 7 of the phase transfer reactor 1 for rough washing. Under the action of the pneumatic diaphragm pump, the phosphogypsum after rough washing enters the filter press mechanism 4 through the discharge port 6 at the bottom of the reactor for pressure filtration to remove moisture, and returns to the reactor through the feed inlet 7 of the phase transfer reactor 1, and then water (passed in through the water inlet 8) and the phase transfer agent Na are added at the same time. 2 Y (introduced from feed port 7), phosphogypsum undergoes phase transition in the kettle, and Ca + The leached liquid is then transported to the filter press 4 by the pneumatic diaphragm pump 12 for solid-liquid separation. + Entering the liquid phase, the liquid phase returns to the phase transfer reactor 1 for aging reaction, is separated from other soluble impurities, and is then transported to the filter press mechanism 4 for solid-liquid separation. Impurities in the solid phase phosphogypsum are removed, and the main component is CaY. It is conveyed by a belt into the carbonization reactor 2, and water is passed through the water inlet 8 of the carbonization reactor 2, and sodium hydroxide is passed through the feed port 7 to form a sodium hydroxide solution. Carbon dioxide is then blown into the carbonization reactor 2 through the gas mixing mechanism 11 at the bottom of the carbonization reactor 2. Nano calcium carbonate suspension is generated in the reactor by reaction. The suspension enters the filter press mechanism 4 for solid-liquid separation. The solid phase is nano calcium carbonate, and the liquid phase re-forms the phase transfer agent Na 2 Y, transported back to the phase transfer reactor 1 for reuse, the solid phase enters the modification reactor 3, water is introduced into the water inlet 8 of the modification reactor 3, and the modifier is introduced into the feed port 7, a modification reaction occurs in the reactor, and an active nano calcium carbonate suspension is generated, and the suspension enters the filter press mechanism 4 for solid-liquid separation, and the solid phase is active nano calcium carbonate. The liquid phase after solid-liquid separation is drawn into the corresponding reactor by a vacuum pump 5 under negative pressure.

[0027] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0028] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A device for preparing active nano calcium carbonate from phosphogypsum, characterized in that: The invention comprises a phase transfer reactor (1), a carbonization reactor (2), a modification reactor (3), a filter press mechanism (4) and a vacuum pump (5), wherein: the phase transfer reactor (1), the carbonization reactor (2) and the modification reactor (3) are each provided with a discharge port (6) at the bottom, and a feed port (7), a water inlet (8) and a vacuum air path interface (9) at the top; each discharge port (6) is connected to the inlet of the filter press mechanism (4), each feed port (7) is connected to the outlet of the filter press mechanism (4), each water inlet (8) is connected to a water source (10), and each vacuum air path interface (9) is connected to the vacuum pump (5).

2. The device for preparing active nano-calcium carbonate from phosphogypsum according to claim 1, characterized in that: The discharge port (6) is connected to the filter press mechanism (4) via a pneumatic diaphragm pump (12).

3. The device for preparing active nano-calcium carbonate from phosphogypsum according to claim 1, characterized in that: The feed port (7) is connected to the filter press mechanism (4) via a conveyor belt.

4. The device for preparing active nano-calcium carbonate from phosphogypsum according to claim 1, characterized in that: The bottom of the carbonization reaction kettle (2) is also connected to a gas mixing mechanism (11), and the gas mixing mechanism (11) comprises a gas mixing tank, a carbon dioxide gas source connected to the gas mixing tank, and an air source.

5. The device for preparing active nano-calcium carbonate from phosphogypsum according to claim 1, characterized in that: The filter press mechanism (4) comprises a first filter press (13) and a second filter press (14); the first filter press (13) is connected to the carbonization reactor (2) and the modification reactor (3); and the second filter press (14) is connected to the phase transfer reactor (1).

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