A circulating, high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production

Abstract

This invention discloses a circulating high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production, belonging to the field of pearlescent pigment production technology. It includes a hydrolysis reactor, a mechanical filtration unit connected to the hydrolysis reactor via a pipeline conveying unit, and a solvent distillation unit. The key feature is that the hydrolysis reactor contains a crude pearlescent pigment slurry after hydrolysis. The pipeline conveying unit transports the crude pearlescent pigment slurry to the mechanical filtration unit for filtration. The filtration waste liquid is then transported again via the pipeline conveying unit to the solvent distillation unit for distillation separation. This significantly reduces solvent waste and lowers wastewater treatment costs. Furthermore, secondary filtration of low-concentration pearlescent pigment slurry reduces losses by 5%-11%.

Description

Technical Field

[0001] This invention belongs to the field of pearlescent pigment production technology, specifically a cyclical high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production. Background Technology

[0002] Pearlescent pigments are a class of pigments with a pearly luster. They are typically made by coating one or more layers of high-refractive-index metal oxides (such as titanium dioxide, iron oxide, etc.) onto the surface of flaky mica using a liquid-phase deposition method. The core chemical reaction involves the hydrolysis of precursors such as titanium tetrachloride or ferric chloride under acidic conditions.

[0003] Currently, the industry generally uses plate and frame filter presses or centrifuges for mechanical dewatering and then treats the waste liquid. The traditional treatment method for waste liquid is basically to treat it as sewage. The waste liquid usually contains valuable solvents and other components. If it is discharged directly, it will not only waste resources, but also increase the environmental protection costs of wastewater treatment and exhaust gas treatment. Therefore, there is an urgent need for a circulating high-efficiency dewatering and solvent recovery process and system. Summary of the Invention

[0004] The technical problem that the invention aims to solve

[0005] The purpose of this invention is to solve the problems mentioned in the background above.

[0006] Technical solution

[0007] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0008] The present invention discloses a circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production, comprising a hydrolysis reactor, a mechanical pressure filtration unit and a solvent distillation unit connected to the hydrolysis reactor via a pipeline conveying unit. The hydrolysis reactor contains hydrolyzed crude pearlescent pigment slurry. The pipeline conveying unit conveys the crude pearlescent pigment slurry to the mechanical pressure filtration unit. The waste liquid after pressure filtration is again conveyed to the solvent distillation unit via the pipeline conveying unit for distillation separation. The low-concentration pearlescent pigment slurry obtained after separation is conveyed to the mechanical pressure filtration unit via the pipeline conveying unit for secondary pressure filtration.

[0009] Preferably, the mechanical filter press unit includes a filter press main frame, side connecting beams, top protective cover, hydraulic cylinder, filter plate unit, filter plate drain port, liquid inlet flange, liquid receiving tank, and tank bottom interface.

[0010] Preferably, the filter press main frame is divided into front and rear parts and is connected and fixed by side connecting beams arranged on both sides. The top protective cover is installed on the top of the main frame, the hydraulic cylinder is fixedly installed at one end of the main frame, the filter plate unit is arranged inside the main frame and mounted on the side connecting beam, the filter plate drain port is arranged on each filter plate unit, the liquid inlet flange is installed at the other end of the filter press main frame, the liquid receiving tank is installed on the lower side of the filter press main frame, and the tank bottom interface is located at the bottom of the liquid receiving tank.

[0011] Preferably, the solvent distillation unit includes a movable base frame, a distillation tank, a pressure valve, a thermometer, a distillation inlet, a separation tank, a separation outlet, a multi-port drain pipe, a storage tank, an upper pipeline, a right-angle pipeline, a bottom pipeline A, a drain pump, and a bottom pipeline B.

[0012] Preferably, a distillation tank, a separation tank, and a storage tank are fixed on the top of the moving bottom frame. The distillation tank is equipped with a pressure valve and a thermometer. The distillation inlet is located at the bottom of the distillation tank, and the separation outlet is located at the bottom of the separation tank. The separation tank is connected to the top of the distillation tank through an upper pipeline. A multi-port drain pipe is located above the storage tank and is connected to the top of the separation tank through a right-angle pipeline. The storage tank is connected to a drain pump through a bottom pipeline A, and the other end of the drain pump is connected to the separation tank through a bottom pipeline B.

[0013] Preferably, the outlet of the hydrolysis reactor is connected to pipe A, the other end of pipe A is connected to pump A, the other end of pump A is connected to valve A through pipe B, and valve A is connected to the inlet flange on the mechanical pressure filter unit via pipe C.

[0014] Preferably, the liquid outlet is connected to pump B via pipeline E, pump B is connected to valve B via pipeline D, and the other end of valve B is connected to pipeline C.

[0015] Preferably, the distillation inlet is connected to pump C via pipeline E and pipeline F, and the other end of pump C is connected to the bottom interface of the tank via pipeline H.

[0016] A cyclic, high-efficiency dehydration and solvent recovery process for the production of pearlescent pigments, characterized by the following steps:

[0017] S1, the crude pearl pigment slurry in the hydrolysis reactor is transported to the mechanical pressure filter unit through the pipeline conveying unit;

[0018] S2, the mechanical pressure filter unit applies pressure to filter the crude pearl pigment slurry;

[0019] S3, the waste liquid generated by the mechanical pressure filtration unit is transported again to the solvent distillation unit for solvent recovery through the pipeline transportation unit;

[0020] S4, after passing through the solvent distillation unit, the waste liquid is divided into three parts: solvent, water and low-concentration pearlescent pigment slurry. The solvent is pumped to the bottom of the storage tank by the drain pump, and the low-concentration pearlescent pigment slurry is pumped to the mechanical pressure filter unit by pump B for further filtration.

[0021] Beneficial effects

[0022] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0023] 1. The present invention provides a circulating high-efficiency dehydration and solvent recovery process and system for the production of pearlescent pigments, comprising mechanical pressure filtration and solvent distillation recovery, which greatly reduces solvent waste and lowers wastewater treatment costs.

[0024] 2. The present invention provides a circulating high-efficiency dehydration and solvent recovery process and system for the production of pearlescent pigments, wherein the low-concentration pearlescent pigment slurry after distillation is subjected to secondary pressure filtration, reducing losses by 5%-11%;

[0025] 3. The present invention provides a circulating high-efficiency dehydration and solvent recovery process and system for the production of pearlescent pigments. Through Fehr distillation, water, solvent and low-concentration pearlescent pigment slurry are obtained, achieving three benefits in one step, reducing costs and increasing efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a circulating high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production according to the present invention.

[0027] Figure 2 This is a schematic diagram of the auxiliary structure of a circulating high-efficiency dehydration and solvent recovery process and system for the production of pearlescent pigments according to the present invention;

[0028] Figure 3 This is a schematic diagram of the mechanical pressure filter unit of a circulating high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production according to the present invention.

[0029] Figure 4 This is a schematic diagram of the solvent distillation unit of a circulating high-efficiency dehydration and solvent recovery process and system for the production of pearlescent pigments according to the present invention.

[0030] Explanation of the labels in the diagram:

[0031] 100. Hydrolysis reactor;

[0032] 200. Mechanical filter press unit; 201. Filter press main frame; 202. Side connecting beam; 203. Top protective cover; 204. Hydraulic cylinder; 205. Filter plate unit; 206. Filter plate drain port; 207. Liquid inlet flange; 208. Liquid receiving tank; 209. Tank bottom interface;

[0033] 300. Solvent distillation unit; 301. Movable base frame; 302. Distillation tank; 303. Pressure valve; 304. Thermometer; 305. Distillation inlet; 306. Separation tank; 307. Separation outlet; 308. Multi-port drain pipe; 309. Storage tank; 310. Upper piping; 311. Right-angle piping; 312. Bottom piping A; 313. Drain pump; 314. Bottom piping B;

[0034] 400. Pipeline delivery unit; 401. Pipeline A; 402. Pump A; 403. Pipeline B; 404. Valve A; 405. Pipeline C; 406. Valve B; 407. Pipeline D; 408. Pump B; 409. Pipeline E; 410. Pipeline F; 411. Pipeline G; 412. Pump C; 413. Pipeline H. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0038] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0039] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] See attached document Figures 1-4 This embodiment discloses a circulating high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production, comprising a hydrolysis reactor 100, a mechanical pressure filtration unit 200 connected to the hydrolysis reactor 100 via a pipeline conveying unit 400, and a solvent distillation unit 300. The hydrolysis reactor 100 contains hydrolyzed crude pearlescent pigment slurry. The pipeline conveying unit 400 conveys the crude pearlescent pigment slurry to the mechanical pressure filtration unit 200. The waste liquid after pressure filtration is again conveyed to the solvent distillation unit 300 via the pipeline conveying unit 400 for distillation separation. The resulting low-concentration pearlescent pigment slurry is then conveyed to the mechanical pressure filtration unit 200 via the pipeline conveying unit 400 for secondary pressure filtration.

[0042] The mechanical filter press unit 200 in this embodiment includes a filter press main frame 201, a side connecting beam 202, a top protective cover 203, a hydraulic cylinder 204, a filter plate unit 205, a filter plate drain port 206, a liquid inlet flange 207, a liquid receiving tank 208, and a tank bottom interface 209.

[0043] In this embodiment, the filter press main frame 201 is divided into front and rear parts and is connected and fixed by side connecting beams 202 arranged on both sides. The top protective cover 203 is installed on the top of the main frame 201. The hydraulic cylinder 204 is fixedly installed at one end of the main frame 201. The filter plate unit 205 is arranged inside the main frame 201 and is supported on the side connecting beams 202. The filter plate drain port 206 is arranged on each filter plate unit 205. The liquid inlet flange 207 is installed at the other end of the filter press main frame 201. The liquid receiving tank 208 is installed on the lower side of the filter press main frame 201. The tank bottom interface 209 is located at the bottom of the liquid receiving tank 208. The mechanical filter press unit 200 is designed in a split manner, which facilitates installation, debugging and subsequent maintenance. The top protective cover can prevent impurities in the workshop from falling into the equipment and causing pollution.

[0044] The solvent distillation unit 300 of this embodiment includes a movable base frame 301, a distillation tank 302, a pressure valve 303, a thermometer 304, a distillation inlet 305, a separation tank 306, a separation outlet 307, a multi-port drain pipe 308, a storage tank 309, an upper pipe 310, a right-angle pipe 311, a bottom pipe A 312, a drain pump 313, and a bottom pipe B 314.

[0045] In this embodiment, a distillation tank 302, a separation tank 306, and a storage tank 309 are fixed on top of the movable base frame 301. The distillation tank 302 is equipped with a pressure valve 303 and a thermometer 304. The distillation inlet 305 is located below the distillation tank 302, and the separation outlet 307 is located at the bottom of the separation tank 306. The separation tank 306 is connected to the top of the distillation tank 302 via an upper pipe 310. The multi-port drain pipe 308 is located above the storage tank 309 and is connected to the top of the separation tank 306 via a right-angle pipe 311. The storage tank 309 is connected to a drain pump 313 via a bottom pipe A312. The other end of the drain pump 313 is connected to the separation tank 306 via a bottom pipe B314. The installation of a thermometer and a pressure gauge allows for convenient monitoring by personnel to prevent danger caused by excessive pressure or temperature.

[0046] In this embodiment, the outlet of the hydrolysis reactor 100 is connected to pipe A401, the other end of which is connected to pump A402. The other end of pump A402 is connected to valve A404 via pipe B403. Pipe C405 of valve A404 is connected to inlet flange 207 on mechanical filter press unit 200.

[0047] In this embodiment, the separation outlet 307 is connected to the pump B408 via pipeline E409. The pump B408 is connected to the valve B406 via pipeline D407. The other end of the valve B406 is connected to pipeline C405. The low-concentration pearlescent pigment slurry after distillation can be filtered again by the mechanical pressure filter unit 200, reducing losses.

[0048] In this embodiment, the distillation inlet 305 is connected to the pump C412 via pipes E410 and F411, and the other end of the pump C412 is connected to the tank bottom interface 209 via pipe H413.

[0049] A method for operating a circulating, high-efficiency dehydration and solvent recovery process and system for pearlescent pigment production, characterized in that the method includes the following steps:

[0050] S1, the crude pearl pigment slurry in the hydrolysis reactor 100 is transported to the mechanical pressure filter unit 200 through the pipeline conveying unit 400;

[0051] S2, Mechanical pressure filter unit 200 performs pressure filtration on the crude pearl pigment slurry;

[0052] S3, the waste liquid generated by the mechanical pressure filtration unit 200 is transported again to the solvent distillation unit 300 through the pipeline conveying unit 400 for solvent recovery;

[0053] S4, after passing through the solvent distillation unit 300, the waste liquid is divided into three parts: solvent, water and low-concentration pearlescent pigment slurry. The solvent is pumped to the lower part of the storage tank 309 by the discharge pump 313, and the low-concentration pearlescent pigment slurry is pumped to the mechanical pressure filter unit 200 for further filtration by the pump B408.

[0054] In this embodiment, steps S1 and S4 cannot be performed simultaneously and do not interfere with each other.

[0055] The specific steps are as follows:

[0056] 1. When performing step S1, valve A404 is opened, valve B406 is closed, and pump A402 draws the crude pearl pigment slurry in the hydrolysis reactor 100 to the mechanical pressure filter unit 200 for pressure filtration.

[0057] 2. When performing step S4, valve A404 is closed, valve B406 is opened, and pump B408 draws the low-concentration pearlescent pigment slurry from separation tank 306 to mechanical pressure filter unit 200 for pressure filtration.

[0058] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production, comprising a hydrolysis reactor (100), a mechanical pressure filtration unit (200) connected to the hydrolysis reactor (100) via a pipeline conveying unit (400), and a solvent distillation unit (300), characterized in that: The hydrolysis reactor (100) contains hydrolyzed pearlescent pigment crude slurry. The pipeline conveying unit (400) conveys the pearlescent pigment crude slurry to the mechanical pressure filtration unit (200). The waste liquid after pressure filtration is conveyed again through the pipeline conveying unit (400) to the solvent distillation unit (300) for distillation separation. The low-concentration pearlescent pigment slurry obtained after separation is conveyed through the pipeline conveying unit (400) to the mechanical pressure filtration unit (200) for secondary pressure filtration.

2. The circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 1, characterized in that: The mechanical filter press unit (200) includes a filter press main frame (201), a side connecting beam (202), a top protective cover (203), a hydraulic cylinder (204), a filter plate unit (205), a filter plate drain port (206), a liquid inlet flange (207), a liquid receiving tank (208), and a tank bottom interface (209).

3. The circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 2, characterized in that: The filter press main frame (201) is divided into front and rear parts and is connected and fixed by side connecting beams (202) arranged on both sides. The top protective cover (203) is installed on the top of the main frame (201). The hydraulic cylinder (204) is fixedly installed at one end of the main frame (201). The filter plate unit (205) is arranged inside the main frame (201) and mounted on the side connecting beam (202). The filter plate drain port (206) is arranged on each filter plate unit (205). The liquid inlet flange (207) is installed at the other end of the filter press main frame (201). The liquid receiving tank (208) is installed on the lower side of the filter press main frame (201). The tank bottom interface (209) is located at the bottom of the liquid receiving tank (208).

4. The circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 1, characterized in that: The solvent distillation unit (300) includes a movable base frame (301), a distillation tank (302), a pressure valve (303), a thermometer (304), a distillation inlet (305), a separation tank (306), a separation outlet (307), a multi-port drain pipe (308), a storage tank (309), an upper pipeline (310), a right-angle pipeline (311), a bottom pipeline A (312), a drain pump (313), and a bottom pipeline B (314).

5. A circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 4, characterized in that: The movable base frame (301) is fixed with a distillation tank (302), a separation tank (306) and a storage tank (309). The distillation tank (302) is equipped with a pressure valve (303) and a thermometer (304). The distillation inlet (305) is located below the distillation tank (302). The separation outlet (307) is located at the bottom of the separation tank (306). The separation tank (306) is connected to the top of the distillation tank (302) through an upper pipe (310). The multi-port drain pipe (308) is located above the storage tank (309) and is connected to the top of the separation tank (306) through a right-angle pipe (311). The storage tank (309) is connected to a drain pump (313) through a bottom pipe A (312). The other end of the drain pump (313) is connected to the separation tank (306) through a bottom pipe B (314).

6. A circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 1, characterized in that: The outlet of the hydrolysis reactor (100) is connected to pipe A (401), the other end of pipe A (401) is connected to pump A (402), the other end of pump A (402) is connected to valve A (404) through pipe B (403), and pipe C (405) of valve A (404) is connected to the inlet flange (207) on the mechanical pressure filter unit (200).

7. A circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 5, characterized in that: The separation outlet (307) is connected to pump B (408) via pipeline E (409), and pump B (408) is connected to valve B (406) via pipeline D (407). The other end of valve B (406) is connected to pipeline C (405).

8. A circulating high-efficiency dehydration and solvent recovery system for pearlescent pigment production according to claim 5, characterized in that: The distillation inlet (305) is connected to the pump C (412) via pipe E (410) and pipe F (411), and the other end of the pump C (412) is connected to the bottom interface (209) via pipe H (413).

9. A cyclical, high-efficiency dehydration and solvent recovery process for the production of pearlescent pigments, characterized in that, The working method Includes the following steps: S1, the crude pearl pigment slurry in the hydrolysis reactor (100) is transported to the mechanical pressure filter unit (200) through the pipeline conveying unit (400). S2, the mechanical pressure filter unit (200) performs pressure filtration on the crude pearl pigment slurry; S3, the waste liquid generated by the mechanical pressure filtration unit (200) is transported again through the pipeline conveying unit (400) to the solvent distillation unit (300) for solvent recovery; S4, after passing through the solvent distillation unit (300), the waste liquid is divided into three parts: solvent, water and low-concentration pearlescent pigment slurry. The solvent is pumped to the lower part of the storage tank (309) by the drain pump (313), and the low-concentration pearlescent pigment slurry is pumped to the mechanical pressure filter unit (200) by the pump B (408) for further pressure filtration.

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