Method for manufacturing art charcoal pen based on lake desilting sediment

Abstract

The invention relates to a method for manufacturing an art charcoal pen based on lake desilting bottom mud. The method comprises the following steps that the lake desilting bottom mud is sampled to obtain dredged mud; mixing the dredged mud with charcoal powder to obtain mixed mud, wherein the addition amount of the charcoal powder is 2-10% of the weight of dry matters in the dredged mud; carrying out dehydration treatment on the mixed slurry to obtain a mud cake with a preset water content; and the mud cake is extruded into a pen-rod-shaped blank, drying and curing treatment is conducted till the weight is constant, and the art charcoal pen is obtained. According to the method, the bottom mud which is traditionally regarded as waste is successfully converted into an art charcoal pen product with commercial value, so that not only is the resource benefit of the bottom mud greatly improved, but also a brand-new application direction oriented to the cultural creative industry is opened up for bottom mud treatment; in addition, by taking dredging bottom mud and biochar prepared by pyrolyzing lake submerged plants or agricultural wastes as core raw materials, the dependence on specific wood is reduced, and the requirement of sustainable development is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lake dredging utilization, and particularly relates to a method for making art charcoal pens based on lake dredging sludge. BACKGROUND

[0002] Lake dredging is a common engineering measure for lake ecological management and restoration. However, a large amount of sludge is generated during the dredging process. How to efficiently and economically utilize these sludge is a key link to realize the concept of "waste-free city" and circular economy, and is also a long-standing technical problem in the field of environmental engineering. At present, the resource utilization approaches of lake dredging sludge mainly focus on the engineering field, which mainly include: used as soil conditioner or landscaping soil: this method needs to be treated for a long time, such as composting, airing, etc. It has problems such as long processing period, large land occupation, and low economic added value of the final product. Its cost is often higher than that of traditional soil materials, resulting in insufficient market driving force; used for preparing building materials: such as brick making, ceramic particle firing, etc. This method can consume a large amount of sludge, but it usually has specific requirements for the chemical composition and physical properties of the sludge, and the energy consumption in the production process is high, so its application has certain limitations; fermentation to realize energy utilization: such as producing biogas. This technology is complex, and the residues after fermentation still need further treatment, which does not completely solve the problem of final disposal of sludge.

[0003] Charcoal pen is a traditional tool for artists to create sketches, which is usually made of willow, rattan or other wood through high-temperature carbonization. Its production depends on specific wood resources. With the development of cultural and artistic industry, the market demand for charcoal pens with excellent performance, controllable cost and environmentally friendly source is increasing. Therefore, there is an urgent need for a method that can realize high-value resource utilization of lake dredging sludge and provide a sustainable alternative raw material for charcoal pen production, to effectively connect waste resource utilization and cultural industry demand. SUMMARY

[0004] The present application provides a method for making art charcoal pens based on lake dredging sludge, which can realize high-value resource utilization of lake sludge.

[0005] In a first aspect, the present application provides a method for making art charcoal pens based on lake dredging sludge, which comprises the following steps: sampling lake dredging sludge to obtain dredged slurry; mixing the dredged slurry with biochar powder to obtain mixed slurry, the addition amount of the biochar powder being 2% to 10% of the weight of dry matter in the dredged slurry; dehydration treatment of the mixed slurry to obtain sludge cake with a preset water content; The mud cake is extruded into a pen barrel-shaped blank and is subjected to a drying and curing treatment until a constant weight is reached to obtain the art charcoal pen.

[0006] In combination with the first aspect, in an implementation, the sampling of the lake dredging sludge to obtain the dredging slurry further includes: The lake dredging sludge is subjected to heavy metal content detection to ensure that it meets a preset standard.

[0007] In combination with the first aspect, in an implementation, the mixing of the dredging slurry and the biochar powder to obtain the mixed slurry is performed when the water content of the dredging slurry is greater than or equal to a preset water content threshold.

[0008] In combination with the first aspect, in an implementation, the preset water content threshold is 75%.

[0009] In combination with the first aspect, in an implementation, the biochar powder is made from lake submerged plants or agricultural waste pyrolysis, and the particle size of the biochar powder is between 150 mesh and 300 mesh.

[0010] In combination with the first aspect, in an implementation, the dehydration treatment is one of pressure filtration, centrifugation, or vacuum filtration.

[0011] In combination with the first aspect, in an implementation, the preset water content is 50% to 60%.

[0012] In combination with the first aspect, in an implementation, after the mud cake is extruded into the pen barrel-shaped blank, the pen barrel-shaped blank is further subjected to a disinfection treatment.

[0013] In combination with the first aspect, in an implementation, the disinfection treatment is ultraviolet irradiation, and the ultraviolet irradiation is 15 minutes to 30 minutes.

[0014] In combination with the first aspect, in an implementation, the temperature of the drying and curing treatment is 105 DEG C to 120 DEG C.

[0015] The technical scheme provided by the embodiments has the following beneficial effects: 1. The method realizes high-value resource utilization of lake dredging sludge, successfully converts the sludge, which is traditionally regarded as waste, into art charcoal pen products with commercial value, greatly improves the resource utilization efficiency of the sludge, opens up a new application direction for the cultural and creative industry for sludge disposal, and replaces the traditional charcoal pen production that relies on forest resources such as willow and rattan, reduces the dependence on specific wood, and meets the requirements of sustainable development. 2. This method only requires steps such as mixing, dehydration, shaping, and drying. The entire production process is simple, the processing cycle is short, and no additional chemical adhesives are needed during the molding process, thus avoiding secondary pollution and achieving environmental friendliness throughout the entire process from raw materials to products.

[0016] 3. This method can control the hardness and color of the final charcoal pencil by adjusting the proportion of biochar added, effectively meeting the multi-dimensional needs of artists for painting effects such as line density and texture softness during the creative process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a diagram illustrating the main method steps of the present invention; Figure 2 This is a schematic diagram of a charcoal pencil sample from Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the scratches on a charcoal pencil sample according to Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the scratches on carbon pencil samples obtained by adding different proportions of bio-carbon powder in Example 3 of the present invention. Detailed Implementation

[0019] 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 are within the scope of protection of the present application.

[0020] Example 1: Please see Figure 1 Embodiment 1 of this application provides a method for making art charcoal pencils based on lake dredging sediment, including the following steps: S1. Sample the dredged sediment from the lake to obtain dredging mud; When using lake dredging sediment as raw material to obtain dredging mud, it is necessary to conduct raw material safety screening on the lake dredging sediment, that is, to test its heavy metal content to ensure that it meets the preset safety standards.

[0021] The preset safety standard of the present application is the risk screening value requirement specified in the Environmental Labeling Product Technical Requirement Pen (HJ1161-2021). Specifically, the content of the migratable elements in the bottom mud, including but not limited to antimony, arsenic, barium, cadmium, chromium, lead, mercury, and selenium, needs to be lower than the limit value specified in the standard to ensure the safety of human health and meet the national environmental protection requirements.

[0022] S2, mixing the dredged slurry with biochar powder to obtain a mixed slurry, the addition amount of biochar powder being 2% to 10% of the weight of dry matter in the dredged slurry; In the process of mixing the dredged slurry with biochar powder to obtain a mixed slurry, the water content of the dredged slurry needs to be greater than or equal to a preset water content threshold, and the preset water content threshold is preferably 75% to ensure that the dredged slurry is fully and uniformly mixed with the biochar powder. The biochar powder is preferably made from submerged plants (such as cattail and fox tail) salvaged from lakes or common agricultural waste (such as rice husk and straw) under anaerobic conditions through pyrolysis and carbonization, and the particle size of the biochar powder is between 150 mesh and 300 mesh. The preparation of biochar powder is a mature biomass pyrolysis process in the prior art. By introducing this environmentally friendly material, the present application not only effectively conditions the dewatering performance of the lake dredging bottom mud, but also integrates the two types of waste into resources, embodying the environmental protection concept of treating waste with waste.

[0023] In the mixing and conditioning process, the addition amount of biochar powder needs to be accurately controlled, and the addition ratio is 2% to 10% of the weight of dry matter (i.e. absolute dry bottom mud) in the dredged slurry.

[0024] S3, dewatering the mixed slurry to obtain a mud cake with a preset water content; After the mixed slurry is prepared, mechanical dewatering is performed to obtain a mud cake with a water content of 50% to 60%; Mechanical dewatering can be performed by conventional methods such as plate and frame filter pressing, centrifugal dewatering, or vacuum suction filtration.

[0025] S4, extruding the mud cake into a pen barrel-shaped blank and performing drying and solidification treatment until a constant weight is obtained to obtain an art charcoal pen.

[0026] The mud cake with a water content of 50% to 60% obtained in step S3 is put into a specially designed extrusion molding equipment, and the mud cake is continuously extruded into a pen barrel-shaped blank with uniform cross section and consistent density by applying mechanical pressure through a mold. After the blank is formed, it must be sterilized before drying and solidification to eliminate microorganisms that may be carried in the raw material and ensure the safety of the product.

[0027] The present application preferably uses ultraviolet irradiation for sterilization, and the ultraviolet irradiation is for 15 to 30 minutes. After sterilization, the pen-shaped preform is transferred to a drying device for drying and curing. Specifically: The green body is heated in a constant temperature oven at 105℃ to 120℃. This temperature range can efficiently remove residual moisture from the green body while avoiding excessive coking of organic matter or cracking of the green body due to excessive temperature.

[0028] Continue heating until the blank reaches a constant weight, that is, the change rate of mass between two consecutive weighings is less than 0.1%. At this point, the blank has been solidified, has a hard texture, and a uniform color, thus obtaining the final finished art charcoal pencil.

[0029] Example 2: Based on the technical concept of Embodiment 1, this application also provides a method for producing art charcoal pencils using lake dredging sediment: The specific steps are as follows: S1. Sample the dredged sediment from the lake to obtain dredging mud; Mud slurry from dredging a lake was passed through a coarse screen to remove obvious foreign matter and was used for later use. The initial moisture content was measured to be 80%. The biochar powder used was made from straw with a particle size of 200 mesh.

[0030] S2. Mix the dredging mud with biochar powder to obtain a mixed mud. The amount of biochar powder added is 2% to 10% of the dry matter weight in the dredging mud. Place the above-mentioned dredged mud in a mixing container, add biochar in proportion, the addition amount is 7.5%, calculated based on the dry matter weight of the bottom mud in the mud, the addition amount is 7.5%, stir at room temperature for 20 minutes to make the biochar powder and mud fully mixed evenly, to obtain mixed mud.

[0031] S3. Dehydrate the mixed mud to obtain mud cake with a preset moisture content; The mixed slurry was fed into a small plate and frame filter press for filtration. The filtration pressure was controlled at 0.6 MPa and the filtration time was 25 minutes. After filtration, a slurry cake was obtained, and the moisture content of the slurry cake was measured to be 48.5%.

[0032] S4. Extrude the clay cake into a pen-shaped blank and dry and solidify it until a constant weight is achieved to obtain an art charcoal pencil.

[0033] The filtered mud cake is filled into a cylindrical mold and pressure is applied to make it compact and form a charcoal pencil blank. The formed charcoal pencil blank is placed in an ultraviolet sterilization device and irradiated with ultraviolet light with a wavelength of 253.7 nm for 20 minutes to perform surface and shallow sterilization treatment on the charcoal pencil. The charcoal pencil blanks treated with ultraviolet light were transferred to an oven and dried at 110°C for 4 hours to obtain hardened and shaped charcoal pencils. Figure 2As shown; draw a line on the printer paper, and the resulting mark is as follows. Figure 3 As shown.

[0034] Example 3: Based on the same technical concept as Embodiment 1, this application also provides Embodiment 3, which differs from Embodiment 2 in that the proportion of added biochar powder is different; The specific steps are as follows: The dredged mud from a lake was measured to have an initial moisture content of 78.5%. Biochar powder was obtained by pyrolyzing rice straw at 500-550℃, and after crushing and sieving, powder with a particle size of 200 mesh was selected for use. Place the above mud in a mixing container, and accurately add biochar powder in three different mass ratios of 5%, 7.5% and 10% according to the dry matter weight of the bottom mud in the mud. Stir at a constant speed for 20 minutes at room temperature using a mechanical stirrer to ensure that the biochar powder and mud are mixed evenly and without obvious agglomerated particles. The uniformly mixed slurry was transferred to a plate and frame filter press and filtered under a constant pressure of 0.6 MPa for 25 minutes. After filtration, a dense slurry cake was obtained, and the average moisture content was 45.3% according to multi-point sampling. The filter cake is evenly filled into a cylindrical stainless steel mold with an inner diameter of 8mm and extruded to form a pen-shaped blank. The formed pen-shaped blank is placed in an ultraviolet sterilization chamber and irradiated from all directions with ultraviolet light with a main wavelength of 253.7 nm. The irradiation time is strictly controlled within 20 minutes to complete the inactivation of surface and shallow microorganisms.

[0035] The sterilized pen-shaped blanks are neatly arranged in a tray and placed in a forced-air drying oven. They are baked at 110°C for 4 hours until the moisture content of the pen core drops below 5%, finally obtaining a dried and hardened carbon pen core.

[0036] A comparative observation and feel test were conducted on charcoal pen refills prepared with three different proportions of biochar (5%, 7.5%, and 10%). The results showed that the proportion of biochar added had a significant impact on the hardness of the final pen refill: the pen refill with 10% biochar showed the highest hardness and density, felt solid, and was not easy to bend; the pen refill with 7.5% biochar had moderate hardness; while the pen refill with only 5% biochar had relatively low hardness and a certain degree of flexibility. Figure 4 The image shows scratch marks caused by biochar powder at different addition amounts: the overall trend indicates that under the stated process conditions, the greater the amount of biochar powder added, the higher the hardness of the resulting pen lead and the darker the ink color. This provides a clear process basis for obtaining charcoal pen products with different hardness characteristics and ink color by adjusting the amount of biochar powder added.

[0037] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0038] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for making an art charcoal pencil based on lake dredged sludge, characterized in that, The method comprises the following steps: sampling lake dredging sludge to obtain dredging slurry; mixing the dredging slurry with biochar powder to obtain mixed slurry, the biochar powder being added in an amount of 2-10% of the weight of dry matter in the dredging slurry; dehydration treatment of the mixed slurry to obtain mud cake with a preset water content; extruding the mud cake into a pen barrel-shaped blank and performing drying and curing treatment until a constant weight is reached to obtain an art charcoal pen.

2. The method of making an art charcoal pencil based on lake dredged sludge according to claim 1, characterized in that, When the lake dredging sludge is sampled to obtain the dredging slurry, the method further comprises: detecting the heavy metal content of the lake dredging sludge to ensure that it meets the preset standard.

3. The method of making an art charcoal pencil from lake dredged material according to claim 1, wherein, When the dredging slurry is mixed with biochar powder to obtain mixed slurry, the water content of the dredging slurry is greater than or equal to a preset water content threshold.

4. The method of making an art charcoal pencil from lake dredged material according to claim 1, wherein, The preset water content threshold is 75%.

5. The method of making an art charcoal pencil from lake dredged material according to claim 1, wherein, The biochar powder is made from lake submerged plants or agricultural waste pyrolysis, and the particle size of the biochar powder is between 150 mesh and 300 mesh.

6. The method of making an art charcoal pencil from lake dredged material according to claim 1, wherein, The dehydration treatment is one of pressure filtration, centrifugation or vacuum filtration.

7. The method of making an art charcoal pencil from lake dredged material according to claim 1, wherein, The preset water content is 50-60%.

8. The method of making an art charcoal pencil from lake dredged material of claim 1, wherein, After the mud cake is extruded into a pen barrel-shaped blank, the pen barrel-shaped blank is further subjected to disinfection treatment.

9. The method of making an art charcoal pencil from lake dredged material according to claim 8, wherein, The disinfection treatment is ultraviolet irradiation for 15-30 minutes.

10. The method of making an art charcoal pencil from lake dredged material according to claim 1, wherein, The drying and curing treatment is performed at a temperature of 105-120°C.

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