A method for reducing the sticking of fillers in isostatically pressed graphite roasted blanks

Abstract

The present invention belongs to the technical field of isostatic graphite product production, and provides a method for reducing the sticky filler of isostatic graphite roasted blank. The method includes: (1) making refractory mud: putting refractory raw material and solvent in a container at a ratio of 1: 1-5, stirring and mixing to prepare refractory mud; (2) spraying refractory mud: the isostatic graphite green blank is hoisted to the spraying position, and the refractory mud is sprayed to the surface of the green blank to form a coating of 0.4-0.5mm thickness; (3) carrying out a natural drying process, a furnace loading and roasting process, and a furnace cleaning process in sequence. The method can optimize the problem that the filler used in the existing isostatic graphite product green blank roasting process is attached to the surface of the roasted blank and is difficult to clean and affects the quality, thereby playing a role in saving resources, reducing labor costs, simplifying operations, improving production efficiency and improving product quality.

Description

Technical Field

[0001] The invention belongs to the technical field of isostatically pressed graphite product production, and in particular relates to a method for reducing the sticking of fillers to isostatically pressed graphite roasted blanks. Background Art

[0002] Fillers are essential auxiliary materials in the production of isostatically pressed graphite products. The specific process involves wrapping the filler around the isostatically pressed green body and then firing it together. The filler plays a role in heat transfer and preventing deformation during this process.

[0003] Currently, the fillers used in the industry mainly include metallurgical coke, quartz sand, and yellow sand. The filler particle size range is approximately 0-4mm, and the proportion of filler particle size range used by each company varies, with some companies using a larger proportion of fine filler and others using a smaller proportion.

[0004] After isostatic pressing and firing, the filler coating the green body adheres to the surface of the finished product. This presents the following disadvantages: First, cleaning is difficult, requiring significant investment in equipment, manpower, and resources; second, cleaning the surface of the green body takes a long time, which can lead to a longer cycle for the green body to be transferred to the next process (impregnation), increasing time and cost; and third, fine powder of the filler penetrates the surface of the green body during firing, forming a barrier layer that hinders the weight gain during impregnation and affects product quality.

[0005] At present, the difficulty in cleaning and the impact on the quality of the finished product caused by the filler adhering to the surface of the baked billet during the baking process have become problems that need to be solved urgently. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a method for reducing the adhesion of fillers to isostatically pressed graphite calcined blanks; this method can optimize the problem that the fillers used in the existing isostatically pressed graphite green blank calcining process adhere to the surface of the calcined blank and are difficult to clean, thereby affecting the quality, thereby saving resources, reducing labor costs, simplifying operations, improving production efficiency and enhancing product quality.

[0007] In order to achieve the above object, the solution adopted by the present invention is:

[0008] A method for reducing the stickiness of fillers in isostatically pressed graphite calcined blanks comprises: (1) preparing refractory slurry: adding refractory raw materials and solvents in a ratio of 1:1-5 into a container, stirring and mixing to prepare refractory slurry; (2) spraying refractory slurry: hoisting the isostatically pressed graphite blanks to a spraying position, spraying the refractory slurry onto the surface of the blanks to form a coating with a thickness of 0.4-0.5 mm; and (3) sequentially performing a natural drying process, a furnace loading and calcining process, and a furnace cleaning process.

[0009] Furthermore, in a preferred embodiment of the present invention, the refractory raw materials include refractory mud, calcareous inorganic powder, graphite inorganic powder, carbonaceous organic powder, and carbonaceous inorganic powder.

[0010] Furthermore, in a preferred embodiment of the present invention, the solvent includes inorganic and organic solvents including water or alcohol.

[0011] Furthermore, in a preferred embodiment of the present invention, the refractory raw material is refractory mud and the solvent is water.

[0012] Furthermore, in a preferred embodiment of the present invention, the ratio of refractory mud to water is 1:2.5; the refractory mud includes refractory powder and plastic clay in a mass ratio of 1-3:1.

[0013] Furthermore, in a preferred embodiment of the present invention, the natural air-drying process includes: placing the sprayed isostatically pressed graphite green body in a ventilated place to dry naturally.

[0014] Furthermore, in a preferred embodiment of the present invention, the furnace loading and firing step includes: processing the air-dried isostatically pressed graphite green body according to the furnace loading process and the firing process.

[0015] Furthermore, in a preferred embodiment of the present invention, the furnace cleaning process includes: after the isostatically pressed graphite green body is taken out of the furnace, cleaning the hardened coating with a scraper or cleaning equipment.

[0016] The beneficial effects of the method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks provided by the present invention are:

[0017] (1) The method for reducing the sticky filler of isostatically pressed graphite roasted blanks provided by the present invention has a low investment cost, a low cost of using refractory raw materials, and does not require the investment of other equipment or facilities;

[0018] (2) The method for reducing the sticking of fillers to isostatically pressed graphite calcined blanks provided by the present invention has simple spraying operation and high work efficiency;

[0019] (3) The method for reducing the sticking of fillers to isostatically pressed graphite calcined blanks provided by the present invention is easy to clean, and the surface coating of the isostatically pressed graphite calcined blanks hardens and forms a crust after being taken out of the furnace, which can be easily separated from the product;

[0020] (4) The method provided by the present invention for reducing the sticking of fillers in isostatically pressed graphite roasted blanks takes about 0.5 hours to clean a piece of product before the improvement, but only a few minutes after the improvement, which can significantly improve production efficiency and shorten the turnover cycle;

[0021] (5) The method of reducing the sticking of fillers in isostatically pressed graphite roasted blanks provided by the present invention increases the impregnation weight gain rate by 0.6% to 1% after the product flows into the impregnation process, thereby improving the product quality. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0023] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0024] Example 1

[0025] This embodiment provides a method for reducing the sticking of fillers in an isostatically pressed graphite calcined blank, comprising:

[0026] (1) Preparation of refractory mud: adding refractory mud (refractory powder: plastic clay = 1:1) and water in a container at a ratio of 1:1, stirring and mixing to prepare refractory mud;

[0027] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a 0.5 mm thick coating;

[0028] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0029] Example 2

[0030] This embodiment provides a method for reducing the sticking of fillers in an isostatically pressed graphite calcined blank, comprising:

[0031] (1) Preparation of refractory mud: adding refractory mud (refractory powder: plastic clay = 3:1) and water in a ratio of 1:5 into a container, stirring and mixing to prepare refractory mud;

[0032] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a 0.5 mm thick coating;

[0033] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0034] Example 3

[0035] This embodiment provides a method for reducing the sticking of fillers in an isostatically pressed graphite calcined blank, comprising:

[0036] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 2:1) and water in a ratio of 1:2.5 into a container, stir and mix to prepare refractory mud;

[0037] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a 0.5 mm thick coating;

[0038] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0039] Example 4

[0040] This embodiment provides a method for reducing the sticking of fillers in an isostatically pressed graphite calcined blank, comprising:

[0041] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 2:1) and water in a ratio of 1:2.5 into a container, stir and mix to prepare refractory mud;

[0042] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a coating with a thickness of 0.4 mm;

[0043] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0044] Comparative Example 1

[0045] This comparative example provides a method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks, comprising:

[0046] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 2:1) and water in a ratio of 1:2.5 into a container, stir and mix to prepare refractory mud;

[0047] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a coating with a thickness of 0.6 mm;

[0048] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0049] Comparative Example 2

[0050] This comparative example provides a method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks, comprising:

[0051] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 2:1) and water in a ratio of 1:2.5 into a container, stir and mix to prepare refractory mud;

[0052] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a coating with a thickness of 0.7 mm;

[0053] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0054] Comparative Example 3

[0055] This comparative example provides a method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks, comprising:

[0056] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 2:1) and water in a ratio of 1:2.5 into a container, stir and mix to prepare refractory mud;

[0057] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a coating with a thickness of 0.3 mm;

[0058] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0059] Comparative Example 4

[0060] This comparative example provides a method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks, comprising:

[0061] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 0.5:1) and water in a ratio of 1:6 into a container, stir and mix to prepare refractory mud;

[0062] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a 0.5 mm thick coating;

[0063] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0064] Comparative Example 5

[0065] This comparative example provides a method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks, comprising:

[0066] (1) Preparation of refractory mud: Add refractory mud (refractory powder: plastic clay = 4:1) and water in a ratio of 1:0.5 into a container, stir and mix to prepare refractory mud;

[0067] (2) Spraying refractory slurry: The isostatically pressed graphite green body is hoisted to the spraying position, and the refractory slurry is sprayed onto the surface of the green body to form a 0.5 mm thick coating;

[0068] (3) performing the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence to obtain the isostatically pressed graphite roasted blank.

[0069] Experimental Example 1

[0070] Experimental method: Calculate the filler viscosity (%) of the isostatically pressed graphite calcined blanks obtained after cleaning for 5 minutes in Examples 1-4 and Comparative Examples 1-5, and the impregnation weight gain (%) after the isostatically pressed graphite calcined blanks are transferred to the impregnation process;

[0071] Filling material stickiness rate (%) = (weight difference before and after filling of filling material bin) / weight of filling material bin before filling * 100%;

[0072] Immersion weight gain (%) = (weight after immersion - weight before immersion) / weight before immersion * 100%. The results are shown in Table 1:

[0073] Table 1

[0074]

[0075]

[0076] It can be seen from the data in Table 1 that, compared with Comparative Examples 1-5, the method for reducing the sticky filler of the isostatically pressed graphite calcined blank provided by Example 1-4 can achieve complete peeling of the surface coating of the isostatically pressed graphite calcined blank within a cleaning time of 5 minutes, and when the product flows to the impregnation process, the impregnation weight gain rate can be increased by 0.6% to 1%.

[0077] The coating thickness of the sprayed refractory slurry provided in Comparative Examples 1-3 is not within the scope of this application. The coating thickness of Comparative Examples 1-2 is greater than the coating thickness provided in this application. The sticky filler rate within 5 minutes of cleaning is greater than 0%, and the immersion weight gain rate is less than 1%. This shows that increasing the coating thickness has no significance for the peeling of the coating and the subsequent immersion weight gain effect. Instead, it will increase the cleaning time. The coating cannot be completely removed within the same cleaning time, thereby affecting the subsequent immersion weight gain rate. The coating thickness provided in Comparative Example 3 is less than the coating thickness provided in this application. The results show that its sticky filler rate is 20% and the immersion weight gain rate is 0.5%, indicating that the spraying thickness does not meet the specified range of this application, and also affects the sticky filler rate and immersion weight gain rate.

[0078] The raw material ratio of the refractory mud provided in Comparative Examples 4-5 is not within the scope of protection of this application. Its adhesive filler ratio is greater than that of the embodiment of this application and its impregnation weight gain rate is less than that of the embodiment of this application. The results show that within the raw material ratio of the refractory mud of this application, its coating is easier to be peeled off and the impregnation weight gain rate is higher.

[0079] In summary, the method provided by the present invention for reducing the adhesion of fillers to isostatically pressed graphite calcined blanks can optimize the problem that the fillers used in the existing isostatically pressed graphite product green blank calcining process adhere to the surface of the calcined blank and are difficult to clean, thereby affecting the quality, thereby saving resources, reducing labor costs, simplifying operations, improving production efficiency and enhancing product quality.

[0080] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks, characterized in that: include: (1) preparing refractory mud: adding refractory raw materials and solvent in a ratio of 1:2.5 into a container, stirring and mixing to prepare the refractory mud; the refractory raw materials are refractory mud, and the solvent is water; the refractory mud comprises refractory powder and plastic clay in a mass ratio of 1-2:1; (2) spraying the refractory slurry: hoisting the isostatically pressed graphite green body to the spraying position, spraying the refractory slurry onto the surface of the green body to form a coating with a thickness of 0.4-0.5 mm; (3) Carry out the natural drying process, the furnace loading and roasting process, and the furnace cleaning process in sequence.

2. The method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks according to claim 1, wherein: The natural air-drying process comprises: placing the sprayed isostatically pressed graphite green body in a ventilated place to dry naturally.

3. The method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks according to claim 1, wherein: The furnace loading and calcining process includes: processing the dried isostatically pressed graphite green body according to the furnace loading process and the calcining process.

4. The method for reducing the sticking of fillers in isostatically pressed graphite calcined blanks according to claim 1, wherein: The furnace cleaning process includes: after the isostatically pressed graphite green body is taken out of the furnace, cleaning the hardened coating with a scraper or cleaning equipment.

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