Acid-resistant and high-temperature-resistant polypropylene composite cloth covering electrolytic bath

Abstract

The invention belongs to the field of geosynthetic materials, and discloses acid-resistant and high-temperature-resistant polypropylene composite cloth covering an electrolytic bath. The acid-resistant and high-temperature-resistant polypropylene composite cloth comprises silica gel fireproof cloth, polypropylene filament geotextile and a PTFE (Polytetrafluoroethylene) film which are sequentially laminated and compounded, when the acid-resistant and high-temperature-resistant polypropylene composite cloth covers the electrolytic cell, one side of the silica gel fireproof cloth of the acid-resistant and high-temperature-resistant polypropylene composite cloth faces the electrolytic cell to cover the electrolytic cell. The acid-resistant and high-temperature-resistant polypropylene composite cloth can resist erosion of acid chemical substances, and has the functions of sealing (preventing acid mist from overflowing), covering, heat preservation and protection at the same time.

Description

Technical Field

[0001] This invention belongs to the field of geosynthetics, and more specifically, relates to an acid-resistant and high-temperature-resistant polypropylene composite fabric covering an electrolytic cell. Background Technology

[0002] During electrolysis, a series of complex electrochemical reactions occur in an electrolytic cell. Taking common electroplating and hydrometallurgical electrolytic cells as examples, acids in the electrolyte (such as sulfuric acid, hydrochloric acid, and nitric acid) undergo redox reactions under the action of electrode reactions. In the anode region, metals or other substances are oxidized, and water molecules in the solution may undergo electrolysis, producing oxygen and hydrogen ions. When oxygen escapes from the solution, it carries a large number of tiny acid droplets, forming acid mist. Acid mist diffuses into the environment, polluting it and potentially corroding equipment. Existing technologies for preventing acid mist overflow from electrolytic cells have many problems and drawbacks. First, the acid mist collection efficiency is low. Existing acid mist collection hoods, due to their simple structure, cannot effectively cover the entire acid mist generation area of ​​the electrolytic cell, and a large amount of acid mist escapes into the workshop environment from the edges of the collection hood and the operating openings of the electrolytic cell. Taking a common, simple flat-plate collection hood as an example, its fit with the edge of the electrolytic cell is limited. During electrolysis, especially when the electrolyte fluctuates, acid mist can rapidly escape from the edge gaps, causing acid mist to permeate the workshop. This not only harms the health of operators but also corrodes other equipment. Secondly, the sealing performance is poor. Ordinary rubber gaskets and other sealing materials are prone to aging, deformation, and loss of elasticity after long-term contact with acid mist and the acidic electrolyte in the electrolytic cell, leading to seal failure. Moreover, traditional sealing methods rely solely on simple material filling, which cannot cope with the thermal expansion and contraction and mechanical vibration of the electrolytic cell during operation, causing gaps to appear at the seals, allowing acid mist to escape. Furthermore, the overall system lacks coordination; waterproofing, insulation, and acid mist prevention modules operate independently, failing to form an organic whole. For example, the ventilation system did not take into account the impact on the workshop temperature when exhausting acid mist, which may lead to excessive temperature fluctuations in the electrolytic cell, affecting the stability of the electrolytic reaction and indirectly increasing the amount of acid mist generated. The design of the insulation structure also did not fully consider the auxiliary role of acid mist collection and sealing. The functions of each part cannot promote each other and may even interfere with each other.

[0003] Furthermore, due to the exothermic reactions, localized abnormal high temperatures, and heat transfer media occurring within the electrolytic cell, existing equipment for preventing acid mist overflow inevitably needs to possess high-temperature resistance characteristics. If the equipment loses its integrity due to high temperatures, its acid mist prevention function will completely fail.

[0004] Therefore, there is an urgent need to develop a new type of acid-resistant and high-temperature-resistant polypropylene composite cloth for covering electrolytic cells. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an acid-resistant and high-temperature-resistant polypropylene composite fabric for covering electrolytic cells. This acid-resistant and high-temperature-resistant polypropylene composite fabric can resist the erosion of acidic chemicals and simultaneously possesses functions of sealing (preventing acid mist leakage), covering, heat insulation, and protection.

[0006] To achieve the above objectives, the present invention provides an acid-resistant and high-temperature resistant polypropylene composite cloth covering an electrolytic cell, the acid-resistant and high-temperature resistant polypropylene composite cloth comprising, in sequence, a silicone fireproof cloth, a polypropylene filament geotextile and a PTFE membrane. When the acid-resistant and high-temperature-resistant polypropylene composite cloth is applied to the electrolytic cell, the silicone fireproof cloth side of the acid-resistant and high-temperature-resistant polypropylene composite cloth faces the electrolytic cell.

[0007] In this invention, the acid-resistant and high-temperature-resistant polypropylene composite cloth is used with silicone fireproof cloth in direct contact with the electrolytic cell, thus achieving high-temperature resistance.

[0008] According to the present invention, preferably, the basis weight of the polypropylene filament geotextile is 500-600 g / m. 2 .

[0009] According to the present invention, preferably, the thickness of the PTFE membrane is 30-50 μm.

[0010] According to the present invention, preferably, the thickness of the silicone fireproof cloth is 1.5-2.5 mm.

[0011] According to the present invention, preferably, one side of the polypropylene filament geotextile is thermally bonded to the PTFE membrane.

[0012] According to the present invention, preferably, one side of the polypropylene filament geotextile is combined with a PTFE membrane to obtain a composite structure, and the boundary of the composite structure is a lock-edge structure.

[0013] According to the present invention, preferably, the overlock structure is obtained by impregnating a structure including the overlock seam with silicone resin and then curing it.

[0014] According to the present invention, preferably, the immersion time is 3-5 minutes.

[0015] According to the present invention, preferably, the curing treatment is performed at a temperature of 80-130°C for a time of 1-2 hours.

[0016] According to the present invention, preferably, the other side of the polypropylene filament geotextile is bonded and composited with the silicone fireproof cloth through a modified acrylate layer and a silicone layer; the other side of the polypropylene filament geotextile, the modified acrylate layer, the silicone layer and the silicone fireproof cloth are sequentially stacked.

[0017] According to the present invention, preferably, the temperature resistance of the acid-resistant and high-temperature resistant polypropylene composite fabric is 145-200℃.

[0018] The beneficial effects of the technical solution of the present invention are as follows: The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell of the present invention can resist the erosion of acidic chemicals, and at the same time has the functions of sealing (preventing acid mist leakage), covering, heat preservation and protection. Specifically: 1. The acid-resistant and high-temperature-resistant polypropylene composite fabric of the present invention adopts a composite structure, and achieves super acid resistance stability through the synergistic effect of three layers of materials, avoiding the problems of aging, deformation, and loss of elasticity caused by long-term contact with acid mist and acidic electrolyte in the electrolytic cell. Specifically: Silicone fireproof cloth: Silicone material itself has excellent acid corrosion resistance, and the fiber structure of silicone fireproof cloth is dense, which can directly block the contact between acid mist and the sealing surface (the membrane structure formed by the composite of PTFE membrane and polypropylene filament geotextile surface); the thickness design of silicone fireproof cloth not only enhances physical strength, but also buffers the penetration rate of acidic substances, avoiding the problem of rapid corrosion of traditional thin rubber gaskets. Polypropylene filament geotextile: Polypropylene molecular chains do not contain functional groups that are easily damaged by acids, and are resistant to corrosion from common electrolyte acids such as sulfuric acid, hydrochloric acid, and nitric acid. In addition, the filament structure has high tensile strength and is not easy to break or deform after long-term use, thus solving the problem of loss of elasticity caused by the fragile structure of traditional sealing materials. PTFE membrane: PTFE (polytetrafluoroethylene) has the property of being a "king of acid resistance", which can resist the erosion of almost all strong acids. Its smooth and non-stick surface can prevent long-term corrosion caused by electrolyte residue. It further provides double protection for the sealing surface (the membrane structure formed by the composite of PTFE membrane and polypropylene filament geotextile). In summary, the three materials—silicone fireproof cloth, polypropylene filament geotextile, and PTFE membrane—are bonded together with a silicone layer and a modified acrylate layer through edge locking, forming a seamless, sealed structure that eliminates the vicious cycle of "acid mist corrosion - material aging - seal failure" from the source.

[0019] 2. The acid-resistant and high-temperature-resistant polypropylene composite fabric of the present invention, through the combination of elasticity and toughness, can cope with the thermal expansion and contraction and mechanical vibration of the electrolytic cell during operation, achieving dynamic sealing. Specifically: Elastic compensation of silicone fireproof cloth: Silicone material has good elastic recovery. When the electrolytic cell expands due to heat from the electrolytic reaction, the silicone fireproof cloth can stretch synchronously with the sealing surface (the membrane structure formed by the composite of PTFE membrane and polypropylene filament geotextile), avoiding gaps caused by the tensile breakage of traditional rigid sealing materials; when the temperature drops and shrinks, the elasticity of the silicone fireproof cloth can make the sealing surface fit tightly against the electrolytic cell, eliminating gaps caused by cold shrinkage. The toughness and buffering properties of polypropylene filament geotextile: The fiber structure of polypropylene filament geotextile has excellent toughness, which can absorb the mechanical vibration energy generated during the operation of the electrolytic cell and prevent the sealing material from being misaligned with the edge of the electrolytic cell due to vibration; at the same time, the porous structure of polypropylene filament geotextile can disperse vibration stress and prevent the local sealing surface from being damaged due to stress concentration. Sealing enhancement through edge locking and bonding processes: The composite structure edges of the composite fabric of this invention are treated with edge locking to avoid sealing failure caused by interlayer separation; the high adhesion performance of the silicone layer-modified acrylate layer ensures that the three layers of materials are tightly bonded to the surface of the electrolytic cell, and the integrity of the sealing surface can be maintained even under temperature and vibration changes, completely solving the defect of traditional seals that "static filling cannot cope with dynamic changes".

[0020] 3. The acid-resistant and high-temperature-resistant polypropylene composite fabric of the present invention achieves organic synergy among various functional modules through a multi-functional integrated design, solving the problem of separate functions for waterproofing, heat insulation, and acid mist prevention in the prior art. Specifically: (1) Thermal insulation-acid mist prevention linkage design The three-layer material maintains a stable temperature inside the electrolytic cell (the porous structure of the polypropylene filament geotextile forms an air insulation layer, which, combined with the low thermal conductivity of the silicone fireproof cloth, effectively reduces heat loss from the electrolytic cell; the sealing properties of the PTFE membrane also prevent the leakage of high-temperature gases from the cell, thus maintaining a stable temperature inside the electrolytic cell). By stabilizing the temperature inside the electrolytic cell (temperature fluctuations can lead to unstable electrolyte evaporation rates), the evaporation rate of the electrolyte is kept stable, reducing acid mist generation from the source; at the same time, temperature stability also avoids sealing gaps caused by frequent thermal expansion and contraction, further enhancing the anti-acid mist effect, forming a synergistic cycle of "heat preservation - temperature stabilization - mist reduction - strong sealing"; (2) Seamless synergy between waterproofing and acid mist protection In the prior art, waterproof modules and acid mist prevention modules are often designed independently, which can easily lead to problems such as the waterproof structure hindering acid mist collection or the acid mist prevention device damaging the waterproof seal. The three-layer composite structure of the present invention does not require the addition of separate waterproof or acid mist prevention components.

[0021] 4. The acid-resistant and high-temperature-resistant polypropylene composite fabric of the present invention has high-temperature resistance properties, specifically: The dual function of silicone fireproof cloth: not only can it directly resist the external high temperature environment with its upper limit of 200℃, but its fireproof fiber structure can also block the sparks generated by the anodic effect and prevent the high temperature melt from damaging the inner material; the thickness design forms a gradient heat-resistant layer to buffer the instantaneous high temperature impact. Heat resistance enhancement of polypropylene filament geotextile: Through filament fiberization treatment, the heat resistance temperature of polypropylene is increased from the conventional 110℃ to over 130℃. At the same time, the porous structure is used to form an air insulation layer to reduce the heat load of the PTFE membrane. High-temperature stability of PTFE membrane: Relying on its 260℃ temperature resistance, it resists the corrosion of high-temperature acid mist in the electrolytic cell, and at the same time forms a "high and low temperature complementarity" with silicone fireproof cloth - when the inner layer temperature approaches the tolerance limit of silicone fireproof cloth, PTFE membrane can act as a second heat-resistant barrier to avoid overall structural failure. High-temperature curing edge treatment: Existing edge treatments are prone to detachment at high temperatures. This invention impregnates the edge stitching with silicone resin, and after curing, the temperature resistance of the edge is consistent with that of the substrate, thus avoiding interlayer cracking. Gradient Adhesion Technology: This invention abandons conventional double-sided adhesive and adopts a composite adhesive layer of "silicone layer-modified acrylate layer". The silicone layer is compatible with silicone fireproof cloth, and the modified acrylate layer is tightly bonded to polypropylene filament geotextile. The overall temperature resistance of the "silicone layer-modified acrylate layer" reaches 200℃, solving the industry problem of adhesion failure at high temperatures. Dynamic sealing compensation at high temperatures: The silicone fireproof cloth retains its elasticity at high temperatures, which can cope with the thermal expansion and contraction caused by temperature fluctuations in the electrolytic cell, and avoid the sealing gaps caused by the loss of elasticity of traditional materials at high temperatures. Heat resistance and insulation linkage for mist reduction: The multi-layer heat-resistant design of the composite structure simultaneously achieves efficient heat insulation, reducing heat loss from high-temperature equipment such as electrolytic cells and avoiding a surge in acid mist caused by temperature fluctuations, forming a synergistic closed loop of "heat resistance and insulation - stable operating conditions - reduced acid mist".

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0023] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0024] Figure 1 This diagram illustrates the structure of an acid-resistant and high-temperature-resistant polypropylene composite cloth covering an electrolytic cell, as provided in Embodiment 1 of the present invention.

[0025] The annotations in the attached figures are explained as follows: 1. Silicone fireproof cloth, 2. Polypropylene filament geotextile, 3. PTFE membrane, 2-1. Modified acrylate layer, 2-2. Silicone layer. Detailed Implementation

[0026] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0027] In the following examples and comparative examples: The silicone fireproof cloth was purchased from Suzhou Weidun Composite Fabric Co., Ltd. The polypropylene filament geotextile was purchased from Tiandingfeng Holdings Co., Ltd. The PTFE membrane was purchased from Jiangsu Baizhe Polymer Co., Ltd. The silicone resin was purchased from Shandong Dayi Chemical Co., Ltd. The modified acrylate layer was purchased from Shandong Rike Chemical Co., Ltd. The silicone for the silicone layer was purchased from Qingdao Mintai High-Tech Materials Co., Ltd. The double-sided tape was purchased from Dongguan Changying Packaging Products Co., Ltd. The overlock stitching is made of high-strength polyester sewing thread, purchased from Nantong Weirui Thread Industry Co., Ltd.

[0028] Example 1

[0029] This embodiment provides an acid-resistant and high-temperature-resistant polypropylene composite cloth covering an electrolytic cell, such as... Figure 1 As shown, the acid-resistant and high-temperature resistant polypropylene composite fabric includes silicone fireproof fabric 1, polypropylene filament geotextile 2 and PTFE membrane 3, which are sequentially stacked and composited. When the acid-resistant and high-temperature-resistant polypropylene composite cloth is placed on the electrolytic cell, the silicone fireproof cloth 1 side of the acid-resistant and high-temperature-resistant polypropylene composite cloth faces the electrolytic cell.

[0030] The polypropylene filament geotextile 2 has a basis weight of 500 g / m. 2 .

[0031] The thickness of the PTFE membrane 3 is 30 μm.

[0032] The thickness of the silicone fireproof cloth 1 is 2mm.

[0033] One side of the polypropylene filament geotextile 2 is thermally bonded to the PTFE membrane 3 (composite pressure is 5MPa) to obtain a composite structure, and the boundary of the composite structure is provided with a locking edge structure (five-thread sewing machine pattern). The locking edge structure is obtained by impregnating the structure, including the locking edge seam, in silicone resin (impregnation time is 3-5min) and then curing it (curing temperature is 80℃, time is 1-2h).

[0034] The other side of the polypropylene filament geotextile 2 is bonded and composited with the silicone fireproof cloth 1 through a modified acrylate layer 2-1 and a silicone layer 2-2; the other side of the polypropylene filament geotextile 2, the modified acrylate layer 2-1, the silicone layer 2-2 and the silicone fireproof cloth 1 are stacked in sequence.

[0035] Comparative Example 1

[0036] The only difference between this comparative example and Example 1 is that: This comparative example does not include silicone fireproof cloth; When the polypropylene composite fabric of this comparative example is covered on the electrolytic cell, the polypropylene filament geotextile side of the polypropylene composite fabric faces the electrolytic cell.

[0037] Comparative Example 2

[0038] The only difference between this comparative example and Example 1 is that: The overlock structure is only a five-thread sewing machine pattern overlock structure, and it has not been impregnated or cured.

[0039] Comparative Example 3

[0040] The only difference between this comparative example and Example 1 is that: The other side of the polypropylene filament geotextile is bonded to the silicone fireproof cloth with double-sided adhesive; the other side of the polypropylene filament geotextile, the double-sided adhesive, and the silicone fireproof cloth are stacked in sequence.

[0041] Test case

[0042] This test example examines the acid resistance and high temperature resistance of the polypropylene composite fabrics obtained in the examples and comparative examples.

[0043] The test results are shown in Table 1.

[0044] Table 1

[0045] As shown in Table 1, when the surface of the polypropylene filament geotextile is close to the high temperature, the high temperature strength retention rate is low due to the poor temperature resistance of polypropylene itself; the overlock structure that has not been impregnated is damaged under acid treatment and high temperature; when ordinary double-sided tape is used, the product will delaminate under high temperature and the overlock structure will be damaged.

[0046] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An acid-resistant and high-temperature-resistant polypropylene composite cloth covering an electrolytic cell, characterized in that, The acid-resistant and high-temperature resistant polypropylene composite fabric comprises silicone fireproof fabric, polypropylene filament geotextile and PTFE membrane stacked in sequence. When the acid-resistant and high-temperature-resistant polypropylene composite cloth is applied to the electrolytic cell, the silicone fireproof cloth side of the acid-resistant and high-temperature-resistant polypropylene composite cloth faces the electrolytic cell.

2. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1, wherein, The polypropylene filament geotextile has a basis weight of 500-600 g / m. 2 .

3. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1, wherein, The thickness of the PTFE membrane is 30-50 μm.

4. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1, wherein, The thickness of the silicone fireproof cloth is 1.5-2.5mm.

5. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1, wherein, One side of the polypropylene filament geotextile is thermally bonded to the PTFE membrane.

6. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1 or 5, wherein, One side of the polypropylene filament geotextile is combined with a PTFE membrane to form a composite structure, and the boundary of the composite structure is a lock-edge structure.

7. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 6, wherein, The overlock structure is obtained by impregnating a structure, including the overlock seam, in silicone resin and then curing it.

8. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 7, wherein, The soaking time is 3-5 minutes; The curing process is carried out at a temperature of 80-130℃ for 1-2 hours.

9. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1, wherein, The other side of the polypropylene filament geotextile is bonded and composited with the silicone fireproof cloth through a modified acrylate layer and a silicone layer; the other side of the polypropylene filament geotextile, the modified acrylate layer, the silicone layer and the silicone fireproof cloth are stacked in sequence.

10. The acid-resistant and high-temperature-resistant polypropylene composite cloth covering the electrolytic cell according to claim 1, wherein, The acid-resistant and high-temperature-resistant polypropylene composite fabric has a temperature resistance of 145-200℃.

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