Device and method for preparing calcium sulfate whiskers

Abstract

The invention discloses a device and a method for preparing calcium sulfate whiskers. A raw material liquid storage tank; a first discharging opening is formed in the bottom of the first reaction chamber, first feeding openings are formed in the upper end and the lower end of the first reaction chamber respectively, the batching tank is communicated with the first feeding opening in the upper end, and the raw material liquid storage tank is communicated with the first feeding opening in the lower end; a second discharging opening is formed in the bottom of an outer cylinder of the second reaction chamber, and a second feeding opening is formed in the upper end of the second reaction chamber; the second discharging opening is communicated with the feeding end of the filtering device; the heating devices are respectively arranged in the first reaction chamber and the second reaction chamber; the aeration devices are respectively mounted at the bottom of the first reaction chamber and the bottom of the second reaction chamber. The stirring-free continuous reactor is adopted, broken crystals formed by mechanical collision are reduced, so that crystal abrasion is improved, and the quality of the calcium sulfate whisker product is stable.

Description

Technical Field

[0001] The invention relates to the technical field of calcium sulfate whisker preparation, in particular to a device and method for preparing calcium sulfate whisker. Background Art

[0002] Calcium sulfate whisker is a kind of fibrous single crystal material with higher mechanical strength, which is nontoxic, stable in performance and cheap, and can be applied to various industries, such as polyurethane, plastic products, rubber, cement, ceramics, papermaking, adhesives, friction materials and other fields. In recent years, the controllable preparation of calcium sulfate whisker has also been paid more and more attention. Most of the methods for preparing calcium sulfate whisker at present are hydrothermal methods, but this method has high energy consumption and low yield. There is also a method for preparing calcium sulfate whisker by normal pressure acidification, which often requires a highly concentrated acid solution, and it will corrode reaction equipment in the process of separation and drying of samples, increase process cost, and simultaneously along with the increase of solution acidity, the solubility of calcium sulfate will increase, causing more calcium sulfate whiskers to dissolve, resulting in a decrease in the yield of product, and the reacted acid solution also needs certain processing to discharge. CN114197028A describes that gypsum slurry is crystallized into calcium sulfate whiskers in a continuous crystallizer, and CN104928752A uses dolomite or limestone as raw materials to dissolve into an aqueous solution containing calcium ions at room temperature and pressure, and uses a crystal growth promoter containing metal copper ions and a liquid phase organic catalyst to synthesize and prepare calcium sulfate dihydrate whiskers. There is no research on the synthesis process using a simple precipitation method without adding a crystallization agent and a differential pressure synthesis process.

[0003] Based on the above technical problems, the present invention provides a device and method for preparing calcium sulfate whiskers. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for preparing calcium sulfate whiskers to solve the problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following scheme: The present invention provides a device for preparing calcium sulfate whiskers, comprising:

[0006] A batching tank, wherein the batching tank is used to prepare a precipitant;

[0007] A raw material liquid storage tank, wherein the raw material liquid storage tank is used to store the raw material liquid;

[0008] A first reaction chamber, wherein a first discharge port is provided at the bottom of the first reaction chamber, and first feed ports are provided at the upper end and the lower end of the first reaction chamber, respectively, the material mixing tank is connected to the first feed port at the upper end, and the raw material liquid storage tank is connected to the first feed port at the lower end;

[0009] A second reaction chamber, wherein a second discharge port is provided at the bottom of the outer cylinder of the second reaction chamber, a second feed port is provided at the upper end of the second reaction chamber, and the first discharge port is connected to the second feed port;

[0010] A filter device, wherein the second discharge port is connected to a feed end of the filter device;

[0011] A heating device, wherein the first reaction chamber and the second reaction chamber are respectively equipped with the heating device;

[0012] an aeration device, wherein the aeration device is respectively installed at the bottom of the first reaction chamber and the bottom of the second reaction chamber;

[0013] Wherein, the first reaction chamber comprises an inner cylinder and an outer cylinder, the inner cylinder is arranged in the outer cylinder, the top of the outer cylinder is a defoaming zone, the area between the outer cylinder and the inner cylinder is a sedimentation zone, the inner cylinder is a reaction zone, the area between the top of the inner cylinder and the top of the outer cylinder is a fluidization zone, the bottom of the outer cylinder is provided with the first discharge port, and the top and bottom of the inner cylinder are respectively provided with first feed ports;

[0014] The structure of the second reaction chamber is the same as that of the first reaction chamber, and the second discharge port is opened at the bottom end of the outer cylinder of the second reaction chamber, and the second feed port is opened at the top end of the inner cylinder of the second reaction chamber.

[0015] According to the device for preparing calcium sulfate whiskers provided by the present invention, the bottom of the outer cylinder of the first reaction chamber and the bottom of the outer cylinder of the second reaction chamber are both configured as inverted cone structures.

[0016] A method for preparing calcium sulfate whiskers comprises the following steps:

[0017] Step 1, preparing a precipitant solution or slurry in a batching tank, and adding the raw material liquid to the raw material liquid storage tank;

[0018] Step 2: Adding bottom liquid into the first reaction chamber and the second reaction chamber respectively, and the bottom liquid level is flush with the upper edge of the inner cylinder and the second inner cylinder respectively;

[0019] Step 3, heating the base liquid to a predetermined temperature through a heating device and maintaining the temperature;

[0020] Step 4: Add the precipitant in the batching tank and the raw material liquid in the raw material liquid storage tank to the inner cylinder in parallel and continuously for reaction, open the aeration device in the first reactor and adjust the gas volume until the bottom liquid in the inner cylinder can be turned out to the outer cylinder, and the reaction slurry enters the second inner cylinder through the first discharge port at the bottom of the outer cylinder;

[0021] Step 5: After the reaction slurry reacts in the second inner tube for a certain period of time, the aeration device in the second reactor is opened to adjust the gas volume until the bottom liquid in the inner tube can be turned out to the outer tube, and enters the filtering device through the second discharge port at the bottom of the outer tube of the second reactor, and the calcium sulfate whisker product is obtained after filtering by the filtering device.

[0022] According to the preparation method of calcium sulfate whiskers provided by the present invention, in step 1, the precipitant includes one or more of calcium chloride, calcium hydroxide, and calcium oxide; the concentration of the precipitant solution or slurry is 0.5-5 mol / L in molar concentration calculated as calcium.

[0023] According to the method for preparing calcium sulfate whiskers provided by the present invention, in step 1, the raw material liquid includes one or more of sodium sulfate and potassium sulfate.

[0024] According to the method for preparing calcium sulfate whiskers provided by the present invention, in step 2, the base liquid is tap water, and the temperature range of the base liquid is 20-90°C.

[0025] According to the method for preparing calcium sulfate whiskers provided by the present invention, in step five, the reaction time of the precipitant and the raw material liquid in the inner cylinder is 30-120 minutes, and the reaction temperature ranges from 20-90°C.

[0026] According to the method for preparing calcium sulfate whiskers provided by the present invention, in step 5, the ratio of the precipitant to the raw material liquid is as follows: 2- :Ca molar ratio is 1:0.8-1.5 and added continuously in parallel.

[0027] The present invention discloses the following technical effects:

[0028] The present invention adopts a non-stirring continuous reactor, which reduces broken crystals formed by mechanical collisions, thereby improving crystal wear and tear, and the quality of the calcium sulfate whisker product is stable.

[0029] The equipment used in the present invention occupies a small area, has normal pressure and low reaction energy consumption.

[0030] The present invention can continuously produce calcium sulfate whiskers without adding additives, breaking the barrier of intermittent production of calcium sulfate whiskers by traditional hydrothermal method and improving the reusability of treatment liquid.

[0031] The invention is green and environmentally friendly. The method used in the invention does not use strong acids or strong alkalis, does not generate waste gas and solid waste, and does not pose a threat to environmental pollution. Compared with the normal pressure acid hydrolysis method, the water consumption is much lower, and the invention is more green and environmentally friendly.

[0032] The method of the present invention has strong applicability, and similar whiskers such as magnesium carbonate, basic magnesium sulfate, basic magnesium chloride and the like can be prepared by the method.

[0033] The present invention uses soluble sulfate as a raw material, adds an additive without a crystal-changing agent at normal pressure to realize continuous preparation of calcium sulfate whiskers, overcomes the problems of energy consumption and low yield in preparing whiskers by a conventional hydrothermal method, avoids the potential safety hazards caused by pressure reactions, and simultaneously does not introduce additional ions into the reaction system, thereby ensuring the feasibility of reusing the filtrate after the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 The schematic diagram of the structure of the device for preparing calcium sulfate whiskers of the present invention;

[0036] Figure 2 This is a scanning electron microscope image of the calcium sulfate whisker sample prepared in Example 1 of the present invention.

[0037] Among them, 1. batching tank; 2. raw material liquid storage tank; 3. first reaction chamber; 4. second reaction chamber; 5. filtering device; 6. defoaming zone; 7. fluidizing zone; 8. reaction zone; 9. sedimentation zone; 10. aeration device. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figure 1-Figure 2 The present invention provides a device for preparing calcium sulfate whiskers, comprising:

[0041] Batching tank 1, which is used for preparing precipitant;

[0042] A raw material liquid storage tank 2, the raw material liquid storage tank 2 is used to store the raw material liquid;

[0043] A first reaction chamber 3, wherein a first discharge port is provided at the bottom of the first reaction chamber 3, and first feed ports are provided at the upper and lower ends of the first reaction chamber 3, respectively; the batching tank 1 is connected to the first feed port at the upper end, and the raw material liquid storage tank 2 is connected to the first feed port at the lower end;

[0044] A second reaction chamber 4, wherein a second discharge port is provided at the bottom of the outer cylinder of the second reaction chamber 4, a second feed port is provided at the upper end of the second reaction chamber 4, and the first discharge port is connected to the second feed port;

[0045] The filter device 5, the second discharge port is connected to the feed end of the filter device 5;

[0046] Heating device: heating devices are installed in the first reaction chamber 3 and the second reaction chamber 4 respectively;

[0047] An aeration device 10, the aeration device 10 is installed at the bottom of the first reaction chamber 3 and the bottom of the second reaction chamber 4 respectively;

[0048] The first reaction chamber 3 includes an inner cylinder and an outer cylinder, the inner cylinder is arranged inside the outer cylinder, the top of the outer cylinder is a defoaming zone 6, the space between the outer cylinder and the inner cylinder is a settling zone 9, the inner cylinder is a reaction zone 8, the space between the top of the inner cylinder and the top of the outer cylinder is a fluidizing zone 7, the bottom of the outer cylinder is provided with a first discharge port, and the top and bottom of the inner cylinder are provided with first feed ports respectively;

[0049] The structure of the second reaction chamber 4 is the same as that of the first reaction chamber 3 , and the second discharge port is opened at the bottom end of the outer cylinder of the second reaction chamber 4 , and the second feed port is opened at the top end of the inner cylinder of the second reaction chamber 4 .

[0050] According to a further optimized solution, the bottom of the outer cylinder of the first reaction chamber 3 and the bottom of the outer cylinder of the second reaction chamber 4 are both configured as inverted cone structures.

[0051] A method for preparing calcium sulfate whiskers comprises the following steps:

[0052] Step 1, prepare a precipitant solution or slurry in a batching tank 1, and add the raw material liquid into the raw material liquid storage tank 2;

[0053] Step 2: Add bottom liquid into the first reaction chamber 3 and the second reaction chamber 4 respectively, and the bottom liquid level is flush with the upper edge of the inner cylinder and the second inner cylinder respectively;

[0054] Step 3, heating the base liquid to a predetermined temperature through a heating device and maintaining the temperature;

[0055] Step 4: Add the precipitant in the batching tank 1 and the raw material liquid in the raw material liquid storage tank 2 to the inner cylinder in parallel and continuously for reaction, open the aeration device 10 in the first reactor and adjust the gas volume until the bottom liquid in the inner cylinder can be turned out to the outer cylinder, and the reaction slurry enters the second inner cylinder through the first discharge port at the bottom of the outer cylinder;

[0056] Step 5: After the reaction slurry reacts in the second inner tube for a certain period of time, the aeration device 10 in the second reactor is opened to adjust the gas volume until the bottom liquid in the inner tube can be turned out to the outer tube, and enters the filtering device 5 through the second discharge port at the bottom of the outer tube of the second reactor. After filtering by the filtering device 5, a calcium sulfate whisker product is obtained.

[0057] To further optimize the scheme, in step one, the precipitant includes one or more of calcium chloride, calcium hydroxide, and calcium oxide; the concentration of the precipitant solution or slurry is 0.5-5 mol / L in molar concentration calculated as calcium.

[0058] To further optimize the scheme, in step one, the raw material solution includes one or more of sodium sulfate and potassium sulfate.

[0059] The solution was further optimized. In step 2, the base liquid was tap water, and the base liquid temperature ranged from 20 to 90°C.

[0060] The scheme is further optimized. In step five, the reaction time of the precipitant and the raw material liquid in the inner cylinder is 30-120 minutes, and the reaction temperature ranges from 20-90°C.

[0061] To further optimize the scheme, in step 5, the ratio of precipitant to raw material solution is based on SO4 2- :Ca molar ratio is 1:0.8-1.5 and added continuously in parallel.

[0062] Embodiment 1:

[0063] The raw material liquid contains 40g / L of sodium sulfate solution of sulfate radical. First, a precipitant calcium chloride solution is prepared. The concentration of the calcium chloride solution is 2mol / L in terms of calcium. The bottom liquid added to the first reaction chamber 3 and the second reaction chamber 4 of the continuous reaction device is tap water. The bottom liquid is added at a position flush with the inner cylinder of the reaction chamber. The bottom liquid is heated to 60°C by a heating device and the temperature is maintained. The aeration device 10 of the first reaction chamber 3 and the second reaction chamber 4 is turned on, and the gas volume is adjusted until the liquid in the inner cylinder turns out of the outer cylinder; the prepared calcium chloride solution and the sodium sulfate solution are continuously added to the continuous complete set of equipment in parallel. The sodium sulfate solution and the calcium chloride solution are added at a stoichiometric ratio of 1:1.2, and the total reaction residence time in the first reaction chamber 3 is 120min, during the reaction process, the temperature in the first reaction chamber 3 is maintained at 60°C, the reaction slurry enters the second reaction chamber 4 under natural pressure through a pipeline connected to the second reaction chamber 4 from the bottom of the first reaction chamber 3, the gas volume in the second reaction chamber 4 is adjusted until the liquid in the inner cylinder turns out of the outer cylinder, the reaction temperature is controlled to be 60°C, the total residence time of the slurry in the second reaction chamber 4 is 120min, and finally the material is discharged from the bottom of the second reaction chamber 4, and after filtering by a filtering device 5, it is a calcium sulfate whisker product, the product purity CaSO4·2H2O is 99%, and the aspect ratio of the calcium sulfate whisker is 40.

[0064] Example 2

[0065] The raw material liquid contains 40g / L of sodium sulfate solution of sulfate radical. First, a precipitant calcium oxide slurry is prepared. The purity of calcium oxide is ≥90%, and the concentration of calcium oxide slurry is 2mol / L in terms of calcium. The bottom liquid added to the first reaction chamber 3 and the second reaction chamber 4 of the continuous reaction device is tap water. The bottom liquid is added at a position flush with the inner cylinder of the reaction chamber. The bottom liquid is heated to 50°C by a heating device and the temperature is maintained. The aeration device 10 of the first reaction chamber 3 and the second reaction chamber 4 is turned on, and the gas volume is adjusted until the liquid in the inner cylinder turns out of the outer cylinder; the prepared calcium oxide slurry and the sodium sulfate solution are continuously added to the continuous complete set of equipment in parallel. The sodium sulfate solution and the calcium oxide slurry are added at a stoichiometric ratio of 1:0.8, and the total reaction residence time in the first reaction chamber 3 is 200℃. The reaction mixture is stirred for 90 minutes. During the reaction, the temperature in the first reaction chamber 3 is maintained at 50° C. The reaction slurry enters the second reaction chamber 4 under natural pressure through a pipeline connected to the second reaction chamber 4 from the bottom of the first reaction chamber 3. The gas volume in the second reaction chamber 4 is adjusted until the liquid in the inner cylinder turns out of the outer cylinder. The reaction temperature is controlled to be 50° C. The total residence time of the slurry in the second reaction chamber 4 is 90 minutes. Finally, the material is discharged from the bottom of the second reaction chamber 4 and filtered by a filter device 5 to obtain a calcium sulfate whisker product. The product purity CaSO4·2H2O is 95%, and the aspect ratio of the calcium sulfate whisker is 30.

[0066] Embodiment 3:

[0067] The raw material liquid contains 20g / L of potassium sulfate solution of sulfate radical. First, a precipitant calcium hydroxide slurry is prepared. The purity of calcium hydroxide is ≥90%, and the concentration of calcium hydroxide slurry is 1mol / L in terms of calcium. The bottom liquid added to the first reaction chamber 3 and the second reaction chamber 4 of the continuous reaction device is tap water. The bottom liquid is added at a position flush with the inner cylinder of the reaction chamber. The bottom liquid is heated to 20°C by a heating device and the temperature is maintained. The aeration device 10 of the first reaction chamber 3 and the second reaction chamber 4 is turned on, and the gas volume is adjusted until the liquid in the inner cylinder turns out of the outer cylinder; the prepared calcium oxide slurry and sodium sulfate solution are continuously added to the continuous complete set of equipment in parallel. The sodium sulfate solution and the calcium oxide slurry are added at a stoichiometric ratio of 1:0.8, and the total reaction residence time in the first reaction chamber 3 is 20℃. The reaction temperature is 120 minutes. During the reaction, the temperature in the first reaction chamber 3 is kept at 20°C. The reaction slurry enters the second reaction chamber 4 under natural pressure through a pipeline connected to the second reaction chamber 4 from the bottom of the first reaction chamber 3. The gas volume in the second reaction chamber 4 is adjusted until the liquid in the inner cylinder turns out of the outer cylinder. The reaction temperature is controlled at 20°C. The total residence time of the slurry in the second reaction chamber 4 is 120 minutes. Finally, the material is discharged from the bottom of the second reaction chamber 4. After filtering through a filtering device 5, calcium sulfate whiskers are obtained. The product purity CaSO4·2H2O is 93%, and the aspect ratio of the calcium sulfate whiskers is 20.

[0068] Embodiment 4:

[0069] The raw material liquid contains a potassium sulfate solution of 60 g / L sulfate ion. First, a precipitant calcium chloride solution is prepared. The concentration of the calcium chloride solution is 0.5 mol / L in terms of calcium. The bottom liquid added to the first reaction chamber 3 and the second reaction chamber 4 of the continuous reaction device is tap water. The bottom liquid is added at a position flush with the inner cylinder of the reaction chamber. The bottom liquid is heated to 90° C. by a heating device and the temperature is maintained. The aeration device 10 of the first reaction chamber 3 and the second reaction chamber 4 is turned on, and the gas volume is adjusted until the liquid in the inner cylinder turns out of the outer cylinder; the prepared calcium chloride solution and potassium sulfate solution are continuously added to the continuous complete set of equipment in parallel. The potassium sulfate solution and the calcium chloride solution are added at a stoichiometric ratio of 1:1.5, and the total reaction residence time in the first reaction chamber 3 is The reaction process is carried out for 30 minutes. During the reaction, the temperature in the first reaction chamber 3 is maintained at 90° C. The reaction slurry enters the second reaction chamber 4 under natural pressure through a pipeline connected to the second reaction chamber 4 from the bottom of the first reaction chamber 3. The gas volume in the second reaction chamber 4 is adjusted until the liquid in the inner cylinder turns out of the outer cylinder. The reaction temperature is controlled at 90° C. The total residence time of the slurry in the second reaction chamber 4 is 30 minutes. Finally, the material is discharged from the bottom of the second reaction chamber 4. After filtering by the filtering device 5, it is a calcium sulfate whisker product. The product purity CaSO4·2H2O is 96%, and the aspect ratio of the calcium sulfate whisker is 30.

[0070] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0071] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for preparing calcium sulfate whiskers, characterized in that, include: A batching tank (1), wherein the batching tank (1) is used to prepare a precipitant; A raw material liquid storage tank (2), wherein the raw material liquid storage tank (2) is used to store the raw material liquid; A first reaction chamber (3), wherein a first discharge port is provided at the bottom of the first reaction chamber (3), and first feed ports are provided at the upper end and the lower end of the first reaction chamber (3), respectively, the material mixing tank (1) is connected to the first feed port at the upper end, and the raw material liquid storage tank (2) is connected to the first feed port at the lower end; A second reaction chamber (4), wherein a second discharge port is provided at the bottom of the outer cylinder of the second reaction chamber (4), a second feed port is provided at the upper end of the second reaction chamber (4), and the first discharge port is communicated with the second feed port; A filtering device (5), wherein the second discharge port is connected to a feed end of the filtering device (5); A heating device, wherein the first reaction chamber (3) and the second reaction chamber (4) are respectively equipped with the heating device; an aeration device (10), the aeration device (10) being installed at the bottom of the first reaction chamber (3) and the bottom of the second reaction chamber (4) respectively; The first reaction chamber (3) comprises an inner cylinder and an outer cylinder, the inner cylinder is arranged inside the outer cylinder, the top of the outer cylinder is a defoaming zone (6), the area between the outer cylinder and the inner cylinder is a settling zone (9), the inner cylinder is a reaction zone (8), the area between the top of the inner cylinder and the top of the outer cylinder is a fluidizing zone (7), the bottom of the outer cylinder is provided with the first discharge port, and the top and bottom of the inner cylinder are respectively provided with first feed ports; The structure of the second reaction chamber (4) is the same as that of the first reaction chamber (3), and the second discharge port is opened at the bottom end of the outer cylinder of the second reaction chamber (4), and the second feed port is opened at the top end of the inner cylinder of the second reaction chamber (4).

2. a kind of device for preparing calcium sulfate whisker according to claim 1, is characterized in that: The bottom of the outer cylinder of the first reaction chamber (3) and the bottom of the outer cylinder of the second reaction chamber (4) are both configured as inverted cone structures.

3. A preparation method for preparing calcium sulfate whiskers, based on the device for preparing calcium sulfate whiskers described in any one of claims 1-2, characterized in that, The steps include: Step 1, preparing a precipitant solution or slurry in a batching tank (1), and adding the raw material liquid to a raw material liquid storage tank (2); Step 2: Adding bottom liquid into the first reaction chamber (3) and the second reaction chamber (4) respectively, so that the bottom liquid level is flush with the upper edge of the inner cylinder and the second inner cylinder respectively; Step 3, heating the base liquid to a predetermined temperature through a heating device and maintaining the temperature; Step 4: the precipitant in the batching tank (1) and the raw material liquid in the raw material liquid storage tank (2) are added to the inner cylinder in parallel and continuously for reaction, the aeration device (10) in the first reactor is opened to adjust the gas volume until the bottom liquid in the inner cylinder can be turned out to the outer cylinder, and the reaction slurry enters the second inner cylinder through the first discharge port at the bottom of the outer cylinder; Step 5: After the reaction slurry reacts in the second inner tube for a certain period of time, the aeration device (10) in the second reactor is opened to adjust the gas volume until the bottom liquid in the inner tube can be turned out to the outer tube, and enter the filtering device (5) through the second discharge port at the bottom of the outer tube of the second reactor, and the calcium sulfate whisker product is obtained after filtering by the filtering device (5).

4. a kind of preparation method preparing calcium sulfate whisker according to claim 3, it is characterized in that: In step 1, the precipitant includes one or more of calcium chloride, calcium hydroxide, and calcium oxide; the concentration of the precipitant solution or slurry is 0.5-5 mol / L in molar concentration calculated as calcium.

5. a kind of preparation method preparing calcium sulfate whisker according to claim 3, it is characterized in that: In step 1, the raw material solution includes one or more of sodium sulfate and potassium sulfate.

6. a kind of preparation method preparing calcium sulfate whisker according to claim 3, it is characterized in that: In step 2, the base liquid is tap water, and the base liquid temperature ranges from 20 to 60°C.

7. a kind of preparation method preparing calcium sulfate whisker according to claim 3, it is characterized in that: In step 5, the reaction time of the precipitant and the raw material liquid in the inner cylinder is 30-120 minutes, and the reaction temperature ranges from 20-90°C.

8. A method for preparing calcium sulfate whiskers according to claim 3, characterized in that: In step 5, the ratio of precipitant to raw material solution is based on SO4 2- :Ca molar ratio is 1:0.8-1.5 and added continuously in parallel.

Images