WO2020259343A1

WO2020259343A1 - Slurry pump capable of resisting acidic and high-temperature environment, and production method therefor

Info

Publication number: WO2020259343A1
Application number: PCT/CN2020/096236
Authority: WO
Inventors: 李秋南; 刘凯; 王惠民; 陈敬; 黄涛; 阳白梅; 邢彧; 李再勇; 余小峰; 赵红飞; 汪红刚; 潘帅; 张利军; 贾俊; 胡正坤
Original assignee: 汉江弘源襄阳碳化硅特种陶瓷有限责任公司
Priority date: 2019-06-28
Filing date: 2020-06-16
Publication date: 2020-12-30
Also published as: ZA202100695B; CN110219823B; CN110219823A

Abstract

A slurry pump capable of resisting an acidic and high-temperature environment, comprising a housing (1), a front protective plate (2), an impeller (3), and a rear protective plate (4). Each of the housing (1), the front protective plate (2), the impeller (3), and the rear protective plate (4) comprises metal bodies (a), ceramic layers (b), and silicon carbide composite adhesive layers (c) positioned therebetween; the volume density of the silicon carbide composite adhesive layer (c) is 2.65-2.9 g/cm³; the outer surfaces of the metal bodies (a) and the inner walls of the ceramic layers (b) facing the metal bodies (a) are provided with treatment layers; each treatment layer comprises the following components in parts by mass: 20-40 parts of silicon carbide powder less than 200 meshes, 60-80 parts of vinyl ester resin, 0.1-0.5 part of an accelerant, 0.5-1 part of a curing agent, 0.2-0.5 part of a defoaming agent, 0.2-0.5 part of a flatting agent, and 1-2 parts of a coupling agent. The slurry pump is applicable to different working conditions.

Description

Slurry pump for resisting acid and high temperature environment and preparation method thereof

Technical field

The invention relates to the technical field of slurry pumps, in particular to a slurry pump used to resist acid and high temperature environments and a preparation method thereof.

Background technique

Metal materials are basically used in the manufacture of flow parts of domestic slurry pumps. Metal pumps are expensive because their main components are non-ferrous metals, and they also corrode in strong oxidizing media containing halogen elements such as dilute sulfuric acid and chloride ions, which cannot meet the requirements of working conditions and have a short service life; fluoroplastics Although engineering plastic materials such as high molecular weight polyethylene have excellent corrosion resistance, the mechanical strength of the material itself is not high, and it is generally combined with metal materials. Because the thermal expansion coefficients of such materials and metal materials are different, the temperature The relatively high medium will cause the peeling of plastic and metal materials, which will also damage the pump parts, thus limiting the use temperature of this material, and the plastic material itself is relatively soft and cannot be used for media containing more solid particles. This material is generally compression molded, and the high mold cost also limits the use of this material in the manufacture of large pumps. (Metal materials are wear-resistant but not corrosion-resistant, and rubber materials are corrosion-resistant but not wear-resistant)

Silicon carbide ceramics have excellent wear resistance, acid and alkali resistance, but there are many problems in the application of ceramics to slurry pumps and large-scale: the large-scale silicon carbide ceramics increase the difficulty and cost of production geometrically. The current market The size of the impeller of the pump using silicon carbide ceramics does not exceed 300mm; the strong abrasion resistance and impact resistance of the silicon carbide ceramic materials need to be further improved. The maximum particle size of the slurry transport of the ceramic pumps currently developed on the market does not exceed 2mm; silicon carbide ceramics The existence of certain pores causes slurry leakage problems.

The combination of silicon nitride and silicon carbide in the silicon carbide ceramic material can realize the manufacture of large and special-shaped ceramic pump parts. At present, the existing grouting molding process and casting molding process can complete the product realization. However, the grouting process is to ensure the stability of the grouting slurry. The raw materials have no large-grained aggregates. The moisture content of the grouting molding is more than 16%. The strength of the product body is low. The product shrinks and deforms greatly during the drying and firing process. , Dimensional accuracy is difficult to control and cracks easily occur. Grouting product of silicon nitride bonded silicon carbide ceramic material at the apparent porosity of 20%, bulk density of about 2.5g / cm ^3, the presence of pores 40MPa Flexural strength at room temperature results in a material with a contact area of the slurry delivery greatly increased, The corrosion resistance of the material is reduced, and the leakage problem of the material cannot be solved, and the wear resistance of the product is far from the requirement. Casting molding forming process water can be controlled at about 10%, the silicon nitride product cast binding apparent porosity of the silicon carbide ceramic material at about 15%, bulk density of about 2.65g / cm ^3, flexural strength at room temperature of about 50MPa Compared with the grouting process, the material performance has also been improved to a certain extent, but in the field of large-scale heavy-duty slurry pumps with more severe working conditions, such as the conveying slurry concentration process section, the slurry has strong acid corrosion and some slurry temperature Between 80-95℃, in this working environment, ceramic pumps are required to have good acid resistance, high temperature resistance and impact resistance. At present, ceramic pumps at home and abroad still cannot meet the performance requirements of materials in working conditions.

Summary of the invention

The purpose of the present invention is to provide a slurry pump for resisting acid and high temperature environments and a preparation method thereof, aiming to solve the problem that the current slurry pump cannot meet the requirements of working conditions.

The above-mentioned technical purpose of the present invention is achieved through the following technical solutions: a slurry pump for resisting acid and high temperature environments, comprising a pump casing, a front guard plate, an impeller and a rear guard plate, the pump casing, the The front guard plate, the impeller and the rear guard plate all include a ceramic layer, a silicon carbide composite bonding layer and a metal body, and the silicon carbide composite bonding layer is located between the ceramic layer and the metal body, The volume density of the silicon carbide composite bonding layer is 2.65 to 2.9 g/cm ³ , and the outer surface of the metal body and the ceramic layer are provided with a treatment layer on the inner wall of the metal body. The treatment layer includes the following components:

A further arrangement of the present invention is that the front guard plate and the rear guard plate are both buckled with the pump casing.

The present invention also provides a method for preparing a slurry pump for resisting acid and high temperature environments as described in any one of the above, including the following steps:

S1, prepare the castable, mix the castable, and spare;

S2, the mold is assembled and the mold is fixed, and the assembled mold is fixed on the high-frequency vibration molding machine, where the mold has a molding cavity;

S3, pouring molding, start the high-frequency vibration molding machine, and pour the castable into the molding cavity from the discharge port on the mold until the castable fills the entire cavity;

S4, demoulding, after leaving the formed body for 1-2 hours, demoulding;

S5, drying and trimming, drying and trimming the demolded body;

S6, firing and forming, placing the dried body in a high-temperature nitriding furnace, and gradually increasing the temperature to 1400-1500°C with nitrogen for nitriding and firing to obtain silicon nitride bonded silicon carbide ceramic structural parts;

S7: Perform surface treatment on the ceramic structure to remove floating dust, then inject the reinforced sealing liquid into the ceramic structure, and cure it at 60-120°C for 6-12 hours;

S8, interface treatment: apply one or more treatment layers on the surface of the ceramic structure after S7 treatment, and cure at 60-120°C for 3-8 hours, and apply one or more treatment layers on the surface of the metal body. And curing at 60-120℃ for 3-6 hours;

S9, the ceramic structure and the metal body are combined: the ceramic structure and the metal body are assembled into one body, and the silicon carbide composite bonding slurry is filled into the gap between the ceramic structure and the metal body through high pressure, and the filling is completed and placed at 60-120 Cure at ℃ for 6-12 hours to obtain silicon carbide ceramic composite impeller, front guard plate, rear guard plate and pump casing respectively;

S10: Assemble the composite impeller, front guard plate, rear guard plate and pump casing with metal joint plate, mechanical seal and bracket to form a complete slurry pump;

In parts by mass, the castable in S1 includes

The present invention is further provided as follows: in parts by mass, the silicon carbide sand includes:

The present invention is further configured as follows: in the S5, the demolded body is placed at 35-60°C for 24-36 hours, then the blank is trimmed, and then the blank is dried at 100-140°C for 24-48 hour.

The present invention is further configured as follows: the stepwise heating process of nitrogen gas in S6 is:

S61, heat up to 450-550°C at a rate of 20-50°C/h, and keep it for 6-10h;

S62, heat up to 850-950°C at a rate of 30-60°C/h, and keep it for 2-4h;

S63, heat up to 1050-1150°C at a rate of 30-50°C/h, and keep it for 6-12h;

S64, heat up to 1250-1350°C at a rate of 20-45°C/h, and keep it for 1-3h;

S65, heat up to 1400-1500°C at a rate of 20-40°C/h and keep it for 5-9h;

S66, naturally cool down to room temperature.

A further configuration of the present invention is that the reinforced sealing liquid includes nano-scale inorganic particles, silica sol, resin, defoamer, coupling agent, curing agent and solvent.

The present invention is further provided that: the silicon carbide composite bonding slurry in S9 includes, in parts by mass:

The present invention is further provided that: the resin in the silicon carbide composite bonding slurry in S9 includes one of epoxy resin, vinyl ester resin, furan resin, polyester resin, and bismaleimide resin Or a mixture of several.

A further arrangement of the present invention is: ceramic blocks are provided on the ceramic layer, the ceramic blocks are arranged on the partition tongue and the inner cavity wall of the pump housing, and the front guard plate and the rear guard plate At the intermediate position, the impeller includes a connecting part and a plurality of arc-shaped blade parts on the connecting part, and the ceramic block on the impeller is located at the end of the blade part close to the center of the connecting part.

The beneficial effect of the present invention is: the cross section of the pump casing, the front guard plate, the impeller and the rear guard plate have a five-layer structure, namely, a ceramic layer, a treatment layer, a silicon carbide composite bonding layer, a treatment layer and a metal body. The large particles of silicon carbide sand in the material formula can be used as aggregate to improve the wear resistance of the ceramic layer, and greatly reduce the moisture required for the molding of the castable, and ensure that the slurry moisture is below 8%. Through high-frequency vibration molding, The slurry can flow to a certain extent, so as to fill the entire molding cavity of the mold, which not only makes the mold stand for a short time, but also the green body can have higher strength, and it also ensures that the material is in the drying and firing process The shrinkage rate is small, and it is not easy to produce shrinkage cracks, which can ensure the dimensional accuracy of large ceramic parts. Since the ceramic layer has acid resistance, the parts that come into contact with the acid solution during work can better resist the acid solution. At the same time, the outer surface of the metal body is coated with a treatment layer, and the vinyl ester resin in the treatment layer has better properties. Therefore, even if part of the metal body comes into contact with the acid liquid, it can better prevent the acid liquid from corroding the metal body. The overall acid resistance of the slurry pump is good, and it can be applied to more conditions.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained from these drawings without creative work.

1 is a schematic structural view of an embodiment of a partial structure of a slurry pump used for resisting acid and high temperature environments of the present invention after assembly;

Figure 2 is an exploded view of an embodiment of a slurry pump for resisting acid and high temperature environments according to the present invention, where x indicates the installation position of the ceramic block;

Fig. 3 is a schematic diagram 1 of the fastening structure of the front guard plate/rear guard plate and the pump casing in a slurry pump used to resist acid and high temperature environments according to the present invention;

4 is the second schematic diagram of the fastening structure of the front guard plate/rear guard plate and the pump casing in a slurry pump used to resist acid and high temperature environments according to the present invention;

Fig. 5 is a third schematic diagram of the fastening structure of the front guard plate/rear guard plate and the pump casing in a slurry pump used to resist acid and high temperature environments according to the present invention;

Fig. 6 is a fourth schematic diagram of the fastening structure of the front guard plate/rear guard plate and the pump casing in a slurry pump used to resist acid and high temperature environments of the present invention.

In the figure, 1. pump housing; 2. front guard plate; 3. impeller; 4. rear guard plate; a, metal body; b, ceramic layer; c, silicon carbide composite bonding layer.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Example 1

A slurry pump for resisting acidic and high temperature environments, as shown in Figures 1 to 5, includes a pump casing 1, a front guard plate 2, an impeller 3, and a rear guard plate 4. The pump casing 1, the front The guard plate 2, the impeller 3, and the rear guard plate 4 all include a ceramic layer b, a silicon carbide composite bonding layer c, and a metal body a. The silicon carbide composite bonding layer c is located between the ceramic layer b and Between the metal bodies a, the outer surface of the metal body a and the inner wall of the ceramic layer b opposite to the inner wall of the metal body a are provided with a treatment layer, and the treatment layer includes the following groups in parts by mass Minute:

The front guard plate 2 and the rear guard plate 4 are both buckled with the pump casing 1.

The present invention also provides a method for preparing a slurry pump for resisting acid and high temperature environments, including the following steps:

S1, prepare the castable, mix the castable, and spare;

S4, demoulding, after leaving the formed body for 2 hours, demoulding;

S5, drying and trimming, drying and trimming the demolded body;

S6, firing and molding, placing the dried body in a high-temperature nitriding furnace, and gradually increasing the temperature to 1400°C through nitrogen for nitriding and firing to obtain silicon nitride bonded silicon carbide ceramic structural parts;

S7: Perform surface treatment on the ceramic structure to remove floating dust, and then inject the reinforced sealing liquid into the ceramic structure and cure it at 60°C for 6 hours;

S8, interface treatment: apply one or more treatment layers on the surface of the ceramic structure after S7 treatment, and cure at 60°C for 8 hours, and apply one or more treatment layers on the surface of the metal body a, and Cure for 6 hours at ℃;

S9. Combine the ceramic structure with the metal body a: Assemble the ceramic structure and the metal body a into one, fill the silicon carbide composite bonding slurry into the gap between the ceramic structure and the metal body a through high pressure, and place it in Cure at 60°C for 12 hours to obtain silicon carbide ceramic composite impeller 3, front guard plate 2, rear guard plate 4 and pump casing 1 respectively;

S10: Assemble the compounded impeller 3, front guard plate 2, rear guard plate 4 and pump casing 1 with metal joint plates, mechanical seals, and brackets to form a complete slurry pump;

In parts by mass, the castable in S1 includes

In parts by mass, the silicon carbide sand includes:

In the S5, after the demolded body is placed at 60°C for 24 hours, the blank is trimmed, and then the blank is dried at 140°C for 24 hours.

The process of gradually increasing the temperature by passing nitrogen in S6 is:

S61, heat up to 450°C at a rate of 50°C/h and hold for 10h;

S62, heat up to 950°C at a rate of 30°C/h, and hold for 2h;

S63, heat up to 1050°C at a rate of 50°C/h, and hold for 12h;

S64, heat up to 1350°C at a rate of 20°C/h and keep it for 1h;

S65, heat up to 1400°C at a rate of 40°C/h and keep it for 9h;

S66, naturally cool down to room temperature.

The reinforced sealing solution is prepared by the following steps: in parts by mass, 4 parts of nano-zirconia, 6 parts of nano-aluminum nitride, 10 parts of nano-titanium dioxide, 1 part of aluminum phosphate, 3 parts of sodium tripolyphosphate, silica sol 8 parts, 2 parts coupling agent KH-560, 0.8 parts polyoxyethylene polyoxypropanolamine ether, 7 parts acetone, 40 parts ethanol, 35 parts bismaleimide resin, methyltetrahydrophthalic anhydride 1.8 parts, 4 parts of hexahydrophthalic anhydride, mixed uniformly at 50°C.

The silicon carbide composite bonding slurry in S9 includes by mass parts:

The resin in the silicon carbide composite bonding slurry in the S9 is epoxy resin, the number of parts is 10 parts, the coupling agent is 3 parts of KH550, and the curing agent is 1 part of m-phenylenediamine.

Example 2

A slurry pump used to resist acid and high temperature environments, comprising a pump casing 1, a front guard plate 2, an impeller 3, and a rear guard plate 4, the pump casing 1, the front guard plate 2, the impeller 3, and The rear guard 4 includes a ceramic layer b, a silicon carbide composite bonding layer c, and a metal body a. The silicon carbide composite bonding layer c is located between the ceramic layer b and the metal body a. The outer surface of the metal body a and the ceramic layer b are provided with a treatment layer on the inner wall of the metal body a, and the treatment layer includes the following components in parts by mass:

S1, prepare the castable, mix the castable, and spare;

S4, demoulding, after leaving the formed blank for 1 hour, demoulding;

S5, drying and trimming, drying and trimming the demolded body;

S6, firing and forming, placing the dried body in a high-temperature nitriding furnace, and gradually increasing the temperature to 1500°C with nitrogen for nitriding and firing to obtain silicon nitride bonded silicon carbide ceramic structural parts;

S7: Perform surface treatment on the ceramic structure to remove floating dust, and then inject the reinforced sealing liquid into the ceramic structure and cure it at 100°C for 6 hours;

S8, interface treatment: apply one or more treatment layers on the surface of the ceramic structure after S7 treatment, and cure at 120°C for 3 hours, and apply one or more treatment layers on the surface of the metal body a, and Cure for 3 hours at ℃;

S9. Combine the ceramic structure with the metal body a: Assemble the ceramic structure and the metal body a into one, fill the silicon carbide composite bonding slurry into the gap between the ceramic structure and the metal body a through high pressure, and place it in Cured at 120°C for 6 hours to obtain silicon carbide ceramic composite impeller 3, front guard plate 2, rear guard plate 4 and pump casing 1 respectively;

In parts by mass, the castable in S1 includes

In parts by mass, the silicon carbide sand includes:

In the S5, the demolded body is placed at 35°C for 36 hours, then the blank is trimmed, and then the blank is dried at 100°C for 48 hours.

S61, heat up to 550°C at a rate of 20°C/h, and keep it for 6h;

S62, heat up to 850°C at a rate of 60°C/h, and hold for 2h;

S63, heat up to 1150°C at a rate of 30°C/h, and keep it for 6h;

S64, heat up to 1250°C at a rate of 45°C/h, and keep it for 3h;

S65, heat up to 1500°C at a rate of 20°C/h and keep it for 5h;

S66, naturally cool down to room temperature.

The reinforced sealing liquid is prepared by the following steps: in parts by mass, 3 parts of nano zirconia, 10 parts of nano aluminum nitride, 0.5 parts of nano titanium dioxide, 5 parts of aluminum phosphate, 0.2 parts of sodium tripolyphosphate, and silica sol 5 parts, 1 part coupling agent KH-540, 2 parts polyoxyethylene polyoxypropylene pentaerythritol ether, 3 parts cyclohexanone, 26 parts cyclohexane, 12 parts furan resin, 3 parts phthalic anhydride, at 18 Mix well at ℃.

The silicon carbide composite bonding slurry in S9 includes in parts by mass:

The resin in the silicon carbide composite bonding slurry in S9 is 2 parts of vinyl ester resin and 2 parts of bismaleimide resin, the coupling agent is 1 part of KH792, and the curing agent is 2 parts of diethylenetriamine.

Example 3

A slurry pump for resisting acid and high temperature environments, comprising a pump casing 1, a front guard plate 2, an impeller 3, and a rear guard plate 4. The pump casing 1, the front guard plate 2, the impeller 3, and The rear guard plate 4 includes a ceramic layer b, a silicon carbide composite bonding layer c, and a metal body a. The silicon carbide composite bonding layer c is located between the ceramic layer b and the metal body a. The outer surface of the metal body a and the ceramic layer b are provided with a treatment layer on the inner wall of the metal body a, and the treatment layer includes the following components in parts by mass:

S1, prepare the castable, mix the castable, and spare;

S4, demoulding, after leaving the formed body for 1.5 hours, demoulding;

S5, drying and trimming, drying and trimming the demolded body;

S6, firing and molding, placing the dried green body in a high-temperature nitriding furnace, and gradually increasing the temperature to 1450°C through nitrogen for nitriding and firing to obtain a silicon nitride bonded silicon carbide ceramic structure;

S7: Perform surface treatment on the ceramic structure to remove floating dust, and then inject the reinforced sealing liquid into the ceramic structure and cure it at 80°C for 9 hours;

S8, interface treatment: apply one or more treatment layers on the surface of the ceramic structure after S7 treatment, and cure it at 80°C for 5 hours, apply one or more treatment layers on the surface of the metal body a, and apply it to 110 Cure for 5 hours at ℃;

S9. Combine the ceramic structure with the metal body a: Assemble the ceramic structure and the metal body a into one, fill the silicon carbide composite bonding slurry into the gap between the ceramic structure and the metal body a through high pressure, and place it in Cure at 80°C for 10 hours to obtain silicon carbide ceramic composite impeller 3, front guard plate 2, rear guard plate 4 and pump casing 1 respectively;

In parts by mass, the castable in S1 includes

In parts by mass, the silicon carbide sand includes:

In the S5, the demolded body is placed at 45°C for 30 hours, and then the blank is trimmed, and then dried at 110°C for 36 hours after trimming.

S61, heat up to 500°C at a rate of 30°C/h and keep it for 8h;

S62, heat up to 900°C at a rate of 40°C/h, and keep it for 3h;

S63, heat up to 1100°C at a rate of 40°C/h and keep it for 9h;

S64, heat up to 1300°C at a rate of 30°C/h, and hold for 2h;

S65, heat up to 1450°C at a rate of 30°C/h and keep it for 7h;

S66, naturally cool down to room temperature.

The reinforced sealing liquid is prepared by the following steps: in parts by mass, 3 parts of nano-zirconia, 12 parts of nano-aluminum nitride, 2 parts of nano-titanium dioxide, 3 parts of aluminum phosphate, 4 parts of sodium tripolyphosphate, and silica sol 5 parts, 1 part of coupling agent KH-540, 1 part of polydimethylsiloxane, 5 parts of n-butanol, 18 parts of n-propanol, 17 parts of vinyl resin, 2 parts of dibenzoyl peroxide, over 1 part of tert-butyl oxybenzoate, mix well at 33°C.

The silicon carbide composite bonding slurry in S9 includes in parts by mass:

The resin in the silicon carbide composite bonding slurry in S9 includes 3 parts of furan resin and 2 parts of polyester resin, the coupling agent is 3 parts of KH550, and the curing agent is 2 parts of diaminocyclohexane DACH.

Example 4

S1, prepare the castable, mix the castable, and spare;

S4, demoulding, after leaving the formed body for 1.8 hours, demoulding;

S5, drying and trimming, drying and trimming the demolded body;

S6, firing and molding, placing the dried body in a high-temperature nitriding furnace, and gradually increasing the temperature to 1420°C through nitrogen for nitriding and firing to obtain silicon nitride bonded silicon carbide ceramic structural parts;

S7: Perform surface treatment on the ceramic structure to remove floating dust, and then inject the reinforced sealing liquid into the ceramic structure and cure it at 70°C for 10 hours;

S8, interface treatment: apply one or more treatment layers on the surface of the ceramic structure after S7 treatment, and cure it at 105°C for 7 hours, apply one or more treatment layers on the surface of the metal body a, and Cure for 5 hours at ℃;

S9. Combine the ceramic structure with the metal body a: Assemble the ceramic structure and the metal body a into one, fill the silicon carbide composite bonding slurry into the gap between the ceramic structure and the metal body a through high pressure, and place it in Cure at 100°C for 11 hours to obtain silicon carbide ceramic composite impeller 3, front guard plate 2, rear guard plate 4 and pump casing 1 respectively;

In parts by mass, the castable in S1 includes

In parts by mass, the silicon carbide sand includes:

In the S5, the demolded body is placed at 50°C for 30 hours, and then the blank is trimmed, and then dried at 110°C for 40 hours after trimming.

S61, heat up to 480°C at a rate of 40°C/h, and hold for 6.5h;

S62, heat up to 920°C at a rate of 55°C/h, and hold for 3.5h;

S63, heat up to 1120°C at a rate of 40°C/h, and keep it for 7h;

S64, heat up to 1280°C at a rate of 38°C/h, and hold for 2.5h;

S65, heat up to 1420°C at a rate of 22°C/h and keep it for 8.5h;

S66, naturally cool down to room temperature.

The reinforced sealing liquid is prepared by the following steps: in parts by mass, 6 parts of nano-zirconia, 3 parts of nano-aluminum nitride, 2 parts of nano-titanium dioxide, 1 part of aluminum phosphate, 5 parts of sodium tripolyphosphate, silica sol 4 parts, 8 parts coupling agent KH-540, 2 parts polydimethylsiloxane, 8 parts n-butanol, 15 parts n-propanol, 40 parts epoxy resin, 1 part dibenzoyl peroxide, over 1 part of tert-butyl oxybenzoate, mix well at 30°C.

The silicon carbide composite bonding slurry in S9 includes in parts by mass:

The resin in the silicon carbide composite bonding slurry in S9 is 3 parts epoxy resin, 2 parts furan resin and 1 part polyester resin, coupling agent is 5 parts KH570, and curing agent is 2 parts N-aminoethyl Piperazine.

Among them, the embodiment is consistent with the embodiment. The components of the four binding agents are all in a mass ratio of 1:1:1:1: CMC (sodium carboxymethyl cellulose), PVA (polyvinyl alcohol), lignosulfonate , Silica sol. The additives are all with a mass ratio of 1:1:1:1: ferrosilicon powder, fine silicon powder, yttrium oxide, and yttrium stabilized zirconia. Moreover, the ways in which the front guard plate 2 and the rear guard plate 4 are both buckled with the pump casing 1 are shown in Figures 3 to 6. There are four buckling ways to improve the front guard plate 2, the rear guard plate 4 and the pump. The tightness and stability of the connection between the shells 1.

Consistent with the embodiment The flow rate of the slurry pump manufactured in the fourth embodiment is between 160-4500m ³ /h, the head is between 11-110m, the speed is between 50-1550r/min, and the efficiency is 65%- Between 82%. It is suitable for the transportation of medium with acid concentration (80% H ₂ SO ₄ or HF 5% and below, which is acid resistance), chloride ion concentration ≤60000ppm, weight concentration ≤70%, maximum particle size ≤15mm, and temperature ≤100℃ ( With high temperature resistance), the service life of the same working environment is more than 4 times that of traditional pumps. The volume density of the ceramic layer of Examples 1 to 4 is between 2.75 and 2.95g/cm ³ , the apparent porosity is ≤1%, and the normal temperature flexural strength reaches more than 100MPa, which closes most of the pores of the silicon nitride bonded silicon carbide material , Effectively reduce the contact area between silicon carbide particles and corrosive slurry, solve slurry leakage, and improve the acid and alkali corrosion resistance of the material; silicon carbide particles (2.3-6.7mm) are added to the material of silicon nitride combined with silicon carbide , Improve the strong abrasion resistance of the material.

At the same time, the silicon carbide composite bonding layer c uses coarse, medium and fine silicon carbide particles as aggregates, adding specific resins and additives to make the slurry have good fluidity and can fill the gap between ceramic and metal through high pressure , Curing at no higher than 120°C to form a bonding material with a bulk density between 2.65 and 2.9g/cm ³ and a normal temperature flexural strength ≥ 80MPa, which can bond ceramic and metal composites as a whole.

The pump casing 1, the front guard plate 2, the impeller 3 and the rear guard plate 4 of Embodiments 1 to 4 can also be provided with ceramic blocks (or inserts), wherein the ceramic blocks are arranged on the pump casing 1, the front guard plate 2, the impeller 3 and the rear guard plate 4 where the impact resistance requirements are high, that is, on the partition tongue and the inner cavity wall of the pump casing 1, at the middle position of the guard plate, the impeller 3 includes a connecting part and a number of arcs on the connecting part The blade part (used to drive liquid movement), the ceramic block on the impeller 3 is located at the end of the blade part close to the center of the connecting part. The manufacturing process of the ceramic blocks at different positions is the same, but the shapes are different. The materials of the ceramic blocks are reaction sintered silicon carbide ceramics, pressureless sintered silicon carbide ceramics, recrystallized silicon carbide ceramics or silicon nitride combined with silicon carbide and zirconia. For a certain kind of ceramics, other impact-resistant and wear-resistant ceramic materials or other materials can also be selected according to the actual situation.

It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.

The foregoing description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes or modifications made by persons of ordinary skill in the field of the present invention based on the foregoing disclosure shall fall within the protection scope of the claims.

Claims

A slurry pump for resisting acid and high temperature environment, which is characterized in that it comprises a pump casing (1), a front guard plate (2), an impeller (3) and a rear guard plate (4). The pump casing (1) ), the front guard plate (2), the impeller (3) and the rear guard plate (4) all include a ceramic layer (b), a silicon carbide composite bonding layer (c) and a metal body (a) , The silicon carbide composite bonding layer (c) is located between the ceramic layer (b) and the metal body (a), and the volume density of the silicon carbide composite bonding layer (c) is 2.65 to 2.9 g /cm 3 , the outer surface of the metal body (a) and the ceramic layer (b) are provided with a treatment layer on the inner wall of the metal body (a), and the treatment layer includes The following components:
The slurry pump for resisting acid and high temperature environments according to claim 1, characterized in that: the front guard plate (2) and the rear guard plate (4) are both connected to the pump casing (1). ) Buckle connection.
A method for preparing a slurry pump for resisting acid and high temperature environments according to any one of claims 1 to 2, characterized in that it comprises the following steps:

S1, prepare the castable, mix the castable, and spare;

S2, the mold is assembled and the mold is fixed, and the assembled mold is fixed on the high-frequency vibration molding machine, where the mold has a molding cavity;

S3, pouring molding, start the high-frequency vibration molding machine, and pour the castable into the molding cavity from the discharge port on the mold until the castable fills the entire cavity;

S4, demoulding, after leaving the formed body for 1-2 hours, demoulding;

S5, drying and trimming, drying and trimming the demolded body;

S6, firing and forming, placing the dried body in a high-temperature nitriding furnace, and gradually increasing the temperature to 1400-1500°C with nitrogen for nitriding and firing to obtain silicon nitride bonded silicon carbide ceramic structural parts;

S7: Perform surface treatment on the ceramic structure to remove floating dust, then inject the reinforced sealing liquid into the ceramic structure, and cure it at 60-120°C for 6-12 hours;

S8, interface treatment: apply one or more treatment layers on the surface of the ceramic structure after S7 treatment, and cure at 60-120°C for 3-8 hours, and apply one or more layers on the surface of the metal body (a) Treat the layer and cure it at 60-120°C for 3-6 hours;

S9, the ceramic structure and the metal body (a) are combined: the ceramic structure and the metal body (a) are assembled into one body, and the silicon carbide composite bonding slurry is filled into the gap between the ceramic structure and the metal body (a) through high pressure After filling, place it at 60-120℃ and cure for 6-12 hours to obtain silicon carbide ceramic composite impeller (3), front guard plate (2), rear guard plate (4) and pump casing (1) respectively;

S10: Assemble the composite impeller (3), front guard plate (2), rear guard plate (4) and pump casing (1) with metal joint plates, mechanical seals and brackets to form a complete slurry pump;

In parts by mass, the castable in S1 includes
The method for preparing a slurry pump for resisting acid and high temperature environments according to claim 3, characterized in that: in parts by mass, the silicon carbide sand comprises:
The method for preparing a slurry pump for resisting acid and high temperature environments according to claim 4, characterized in that: in the S5, the demolded body is placed at 35-60°C for 24-36 After hours, trim the billet, and then dry it at 100-140°C for 24-48 hours.
The method for preparing a slurry pump for resisting acidic and high-temperature environments according to claim 4, characterized in that: the process of gradually increasing the temperature of S6 through nitrogen is as follows:

S61, heat up to 450-550°C at a rate of 20-50°C/h, and keep it for 6-10h;

S62, heat up to 850-950°C at a rate of 30-60°C/h, and keep it for 2-4h;

S63, heat up to 1050-1150°C at a rate of 30-50°C/h, and keep it for 6-12h;

S64, heat up to 1250-1350°C at a rate of 20-45°C/h, and keep it for 1-3h;

S65, heat up to 1400-1500°C at a rate of 20-40°C/h and keep it for 5-9h;

S66, naturally cool down to room temperature.
The method for preparing a slurry pump for resisting acid and high temperature environments according to claim 4, characterized in that: the reinforced sealing liquid includes nano-scale inorganic particles, silica sol, resin, defoamer, and Coupling agent, curing agent and solvent.
The method for preparing a slurry pump for resisting acidic and high-temperature environments according to claim 4, characterized in that: the silicon carbide composite bonding slurry in S9 includes by mass parts:
The method for preparing a slurry pump for resisting acid and high temperature environments according to claim 8, wherein the resin in the silicon carbide composite bonding slurry in S9 includes epoxy resin, vinyl One or a mixture of ester resin, furan resin, polyester resin, and bismaleimide resin.
A method for preparing a slurry pump for resisting acid and high temperature environments according to claim 3, characterized in that: ceramic blocks are arranged on the ceramic layer (b), and the ceramic blocks are arranged at all On the partition tongue and inner cavity wall of the pump housing (1), at the intermediate position of the front guard plate (2) and the rear guard plate (3), the impeller (3) includes a connecting portion and a connecting portion The ceramic block on the impeller (3) is located at the end of the blade part close to the center of the connecting part.