A method for preparing green cementitious materials based on waste resource utilization

Abstract

The present invention relates to the field of building materials technology, and in particular to a method for preparing green cementitious materials based on waste resource utilization, comprising: placing crushed municipal solid waste into a pyrolysis reactor for pyrolysis; if the degree of pyrolysis meets a preset standard, separating the pyrolysis gas generated after the pyrolysis, and determining the main components of the municipal solid waste based on the composition and content of the pyrolysis gas; passing the pyrolyzed municipal solid waste into a vertical mill for grinding; determining the degree of grinding to determine whether the municipal solid waste should be re-grinded; if re-grinding is required, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding based on the degree of grinding; correcting the content of the main components of the municipal solid waste based on the number of grinding times and particle size distribution to determine the addition ratio of a cementitious additive; and mixing the ground municipal solid waste with the cementitious additive in proportion to prepare a green cementitious material. The present invention can effectively improve the preparation efficiency of green cementitious materials.

Description

Technical Field

[0001] The present invention relates to the technical field of building environmental protection, and in particular to a method for preparing a green cementitious material based on waste resource utilization. Background Art

[0002] Municipal solid waste not only seriously pollutes soil, water, and air, endangering human health, but also affects urban landscapes and damages the city's image. Researchers have begun exploring ways to convert municipal solid waste into valuable materials, such as cementitious materials. This method is an effective resource utilization method, transforming municipal solid waste into valuable building materials. With the emergence of new technologies and increasing environmental protection requirements, the technical requirements for preparing cementitious materials from municipal solid waste are also increasing.

[0003] Chinese patent publication number CN115321848A discloses a fully solid waste-based low-carbon green ecological cementitious material and a manufacturing method thereof, comprising: S1, accurately measuring various raw materials through a metering scale according to the formula ratio; S2, adding the various raw materials in S1 into a roller vertical mill, grinding them separately to obtain powder materials with a specific surface area of not less than 500m2 / kg and a 30μm sieve residue of not more than 3.0%, and then accurately measuring them according to the formula ratio by a rotor metering scale, entering into a pneumatic and mechanical composite mixer for homogenization, and thus obtaining the fully solid waste-based low-carbon green ecological cementitious material.

[0004] It can be seen that the above invention has the following problems: various raw materials need to be ground separately and then proportioned and homogenized for preparation, which is relatively inefficient. Summary of the Invention

[0005] To this end, the present invention provides a method for preparing a green gelling material based on waste resource utilization, so as to overcome the problem of relatively low efficiency in preparing green gelling materials in the prior art.

[0006] To achieve the above objectives, the present invention provides a method for preparing a green cementitious material based on waste resource utilization, comprising:

[0007] Step S1, placing the crushed municipal solid waste into a pyrolysis reactor for pyrolysis, and determining the degree of pyrolysis based on the change in gas pressure in the pyrolysis reactor;

[0008] Step S2: if the degree of pyrolysis meets the preset standard, separating the pyrolysis gas generated after pyrolysis, and determining the main components of the municipal solid waste based on the composition and content of the pyrolysis gas; the main components include calcium-based inorganic substances;

[0009] Step S3, feeding the pyrolyzed municipal solid waste into a vertical mill for grinding, wherein the feed rate and grinding roller pressure of the vertical mill are determined according to the main components of the municipal solid waste;

[0010] Step S4, determining the grinding degree based on the particle size distribution of the ground municipal solid waste to determine whether to re-grind the municipal solid waste. If re-grinding is required, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding based on the grinding degree;

[0011] Step S5, uniformly mixing the ground municipal solid waste, correcting the content of the main components of the municipal solid waste according to the number of grinding times and the particle size distribution, and determining the addition ratio of the gelling additive based on the detected specific surface area of the municipal solid waste and the corrected content of the main components;

[0012] Step S6: mixing the ground municipal solid waste with the gelling additive in proportion to prepare a green gelling material.

[0013] Furthermore, in step S1, determining the degree of pyrolysis according to the change in gas pressure in the pyrolysis reactor includes:

[0014] The gas pressure in the pyrolysis reactor is continuously collected to determine the gas pressure ratio of each adjacent collection point, and the pyrolysis degree is determined according to each gas pressure ratio and a preset pyrolysis degree comparison table.

[0015] Furthermore, in step S3, determining the feed rate and grinding roller pressure of the vertical mill according to the main components of the municipal solid waste includes:

[0016] Step S31, obtaining the hardness, average particle size and content ratio of the main components of the municipal solid waste;

[0017] Step S32: determining the feed rate and grinding roller pressure of the vertical mill according to the hardness, average particle size and content ratio of the main components of the municipal solid waste.

[0018] Furthermore, the step S32 includes:

[0019] Step S321, determining the basic feeding rate and basic grinding roller pressure of the vertical mill according to the hardness and average particle size of the main components of the municipal solid waste;

[0020] Step S322: adjusting the feeding rate and grinding roller pressure of the vertical mill according to the content ratio of the main components of the municipal solid waste.

[0021] Furthermore, in step S4, determining the degree of grinding according to the particle size distribution of the ground municipal solid waste includes:

[0022] Step S41, determining a particle size characteristic value according to the particle size distribution of the ground municipal solid waste;

[0023] Step S42: determining the degree of grinding based on the particle size characteristic value and a preset degree of grinding comparison table.

[0024] Furthermore, in the step S4, it includes:

[0025] The grinding degree is compared with a preset grinding degree. If the grinding degree does not meet the preset grinding degree, the municipal solid waste is ground again.

[0026] Furthermore, in step S4, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the grinding degree includes:

[0027] Step S43, comparing the grinding degree with a preset grinding degree to determine a first comparison value; wherein the first comparison value is a ratio of the grinding degree to the preset grinding degree;

[0028] Step S44: determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the first comparison value.

[0029] Furthermore, in the step S44, it includes:

[0030] Determining the mill speed for re-grinding of the vertical mill according to the first comparison value and the initial mill speed;

[0031] Determining the grinding roller pressure for re-grinding of the vertical mill according to the first comparison value and the initial grinding roller pressure;

[0032] The initial mill speed is the mill speed during the initial grinding of the vertical mill; and the initial grinding roller pressure is the grinding roller pressure during the initial grinding of the vertical mill.

[0033] Furthermore, in step S5, the content of the main components of the municipal solid waste is corrected according to the number of grinding times and the particle size distribution, including:

[0034] If the grinding times are greater than the preset grinding times and the particle size distribution does not conform to the preset particle size distribution, reducing the content of the main components of the municipal solid waste;

[0035] The reduction ratio is determined according to the ratio of the grinding times to the preset grinding times and the difference between the particle size distribution and the preset particle size distribution.

[0036] Furthermore, in step S5, determining the addition ratio of the gelling additive based on the detected specific surface area of the municipal solid waste and the corrected content of the main components includes:

[0037] If the content of the main component is greater than a preset content threshold, determining the addition ratio of the gelling additive according to the ratio of the corrected specific surface area of the municipal solid waste to the preset specific surface area;

[0038] If the content of the main component is less than or equal to a preset content threshold, the addition ratio of the gelling additive is determined according to the ratio of the content of the main component to the preset content threshold.

[0039] Compared with the prior art, the beneficial effects of the present invention are that the present invention pyrolyzes the crushed urban solid waste, which can reduce the volume and weight of the urban solid waste, facilitate subsequent processing, and thus improve preparation efficiency; and based on the composition and content of the pyrolysis gas generated during the pyrolysis process, the main components of the urban solid waste can be analyzed and determined, which facilitates subsequent proportioning, thereby improving the performance of the green cementitious material. Grinding the pyrolyzed urban solid waste can evenly mix the various components in the urban solid waste and help stimulate the activity of the various components in the urban solid waste, thereby improving the performance of the cementitious material. Correcting the content of the main components of the urban solid waste based on the number of grinding times and the particle size distribution, and determining the addition ratio of the gelling additive based on the detected specific surface area of the urban solid waste and the corrected content of the main components can effectively improve the performance and stability of the prepared green cementitious material.

[0040] Furthermore, the present invention determines the degree of pyrolysis by changing the gas pressure in the pyrolysis reactor, which can improve the energy utilization efficiency of the pyrolysis process and improve the overall preparation efficiency.

[0041] Furthermore, the present invention determines the feeding rate and grinding roller pressure of the vertical mill by the hardness, average particle size and content ratio of the main components of urban solid waste, which can effectively improve the grinding efficiency and grinding accuracy.

[0042] Furthermore, the present invention can reduce the particle size of the urban solid waste by re-grinding the urban solid waste when the grinding degree does not meet the preset grinding degree, thereby improving the uniformity between the various components of the urban solid waste and thus improving the performance of the green cementitious material.

[0043] Furthermore, the present invention determines the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the grinding degree, which can further improve the grinding efficiency.

[0044] Furthermore, the present invention corrects the content of the main components of the urban solid waste based on the number of grinding times and the particle size distribution. If the number of grinding times is greater than the preset number of grinding times and the particle size distribution does not conform to the preset particle size distribution, it indicates that the main components of the urban solid waste are relatively hard and the content is relatively high, then the content of the main components of the urban solid waste is reduced to improve the performance of the prepared green cementitious material. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a flow chart of the method for preparing green gelling materials based on waste resource utilization according to the present invention;

[0046] Figure 2A schematic diagram of a process for determining the feed rate and grinding roller pressure of a vertical mill according to an embodiment of the present invention;

[0047] Figure 3 Schematic diagram of the process of step S32 of an embodiment of the present invention;

[0048] Figure 4 A schematic diagram of a process for determining the degree of grinding according to an embodiment of the present invention;

[0049] Figure 5 The figure is a flow chart of determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below with reference to embodiments. It should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0051] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0052] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0053] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0054] In this embodiment, urban solid waste generally refers to various wastes generated in production and life, including: kitchen solid waste, construction waste (gypsum board, concrete, bricks, etc.), industrial waste (smelting waste, chemical waste, etc.), etc.

[0055] See also Figure 1 As shown, it is a flow chart of a method for preparing a green cementitious material based on waste resource utilization according to the present invention; the present invention provides a method for preparing a green cementitious material based on waste resource utilization, comprising:

[0056] Step S1, placing the crushed municipal solid waste into a pyrolysis reactor for pyrolysis, and determining the degree of pyrolysis based on the change in gas pressure in the pyrolysis reactor;

[0057] In practice, pyrolysis can convert urban solid waste into valuable products, such as bio-oil, combustible gas and biochar, which can be further used to prepare cementitious materials to improve their mechanical properties and durability; the combustible gas and bio-oil produced by pyrolysis can be directly used for energy recovery. Pyrolysis technology can effectively reduce the environmental pollution caused by urban solid waste during landfill and incineration, such as greenhouse gas emissions and soil and groundwater pollution, and effectively improve the resource utilization rate and environmental performance of urban solid waste.

[0058] Specifically, the pyrolysis temperature can be set according to the specific type of urban solid waste in actual application. Preferably, the pyrolysis temperature is set to 500°C to 700°C.

[0059] Specifically, in step S1, determining the degree of pyrolysis according to the change in gas pressure in the pyrolysis reactor includes:

[0060] The gas pressure in the pyrolysis reactor is continuously collected to determine the gas pressure ratio of each adjacent collection point, and the pyrolysis degree is determined according to each gas pressure ratio and a preset pyrolysis degree comparison table.

[0061] During implementation, as the pyrolysis gas increases during the pyrolysis process, the gas pressure in the pyrolysis reactor will gradually increase. In the early stage of pyrolysis, the gas gradually increases, and the increase is relatively large. At this time, the gas pressure ratio of each adjacent collection point gradually increases. In the later stage of pyrolysis, since the reaction is basically completed, the increase in pyrolysis gas decreases, and the gas pressure ratio of each adjacent collection point gradually decreases.

[0062] Specifically, the actual implementer can set a preset pyrolysis degree comparison table based on the actual situation and the pressure changes in the pyrolysis process in the historical data. Preferably, the pyrolysis degree can be divided into 3 to 5 levels, and each level corresponds to a critical pressure ratio. For example: the pyrolysis degree is 3 levels, level 1 is the initial stage of pyrolysis, and the corresponding critical pressure ratio is 2.5; level 2 is the middle stage of pyrolysis, and the corresponding critical pressure ratio is 2.0; level 3 is the end of pyrolysis, and the corresponding critical pressure ratio is 1.3. Adjacent collection points refer to the collection points with adjacent time in each collection moment corresponding to the continuous collection of the pressure in the pyrolysis reactor. The pressure ratio is calculated based on the ratio of the pressure value collected at the current collection point to the pressure value collected at the previous collection point.

[0063] The present invention determines the degree of pyrolysis by changing the gas pressure in the pyrolysis reactor, can monitor the degree of pyrolysis in real time, improve the energy utilization efficiency of the pyrolysis process, and improve the overall preparation efficiency.

[0064] Step S2: if the degree of pyrolysis meets the preset standard, separating the pyrolysis gas generated after pyrolysis, and determining the main components of the municipal solid waste based on the composition and content of the pyrolysis gas; the main components include calcium-based inorganic substances;

[0065] During implementation, the actual implementers can set preset standards based on the actual situation, the specific types and characteristics of urban solid waste, and the preset pyrolysis degree comparison table. Generally, the pyrolysis degree corresponding to the preset standard is the late pyrolysis stage, at which time the pyrolysis reaction is basically complete, usually corresponding to the end of pyrolysis in the pyrolysis degree comparison table. The preset standard generally selects the minimum value of the gas pressure ratio range corresponding to the end of pyrolysis.

[0066] It should be noted that those skilled in the art know that any method in the prior art that can separate the pyrolysis gas generated after pyrolysis falls within the scope of protection of the present invention and will not be described in detail here.

[0067] Specifically, gases produced during the pyrolysis of municipal solid waste include hydrogen, methane, carbon monoxide, carbon dioxide, hydrocarbons, volatile organic compounds, nitrogen, and ammonia. By analyzing the composition and relative amounts of these gases, the types and amounts of substances in the solid waste can be determined. For example, a high methane content indicates that the solid waste contains a high amount of biodegradable components; high carbon monoxide and hydrogen levels indicate a high amount of plastics or other synthetic materials; and a high nitrogen content may indicate a high protein content in the solid waste.

[0068] In implementation, if the total content of methane and nitrogen in a unit volume (1 cubic meter) of municipal solid waste reaches or exceeds 50% to 60% of the total pyrolysis gas, the main substance in the municipal solid waste is determined to be carbon-based, and the content of the main component of the municipal solid waste (calcium-based inorganic matter) is calculated based on the preset content ratio of calcium-based inorganic matter in the kitchen waste;

[0069] If the total content of methane and nitrogen in the unit volume (1 cubic meter) of municipal solid waste is less than 40% to 50% of the total pyrolysis gas, the main substance in the municipal solid waste is determined to be calcium-based, and the content of the main component of the municipal solid waste (calcium-based inorganic matter) is calculated based on the preset content ratio of calcium-based inorganic matter in industrial solid waste;

[0070] Among them, the preset content ratio of calcium-based inorganic matter in kitchen waste can be calculated based on the average value of the calcium-based inorganic matter content ratio obtained by analyzing the composition of kitchen waste after pyrolysis obtained multiple times in historical data, and the preset content ratio of calcium-based inorganic matter in industrial solid waste can be calculated based on the average value of the calcium-based inorganic matter content ratio obtained by analyzing the composition of industrial solid waste after pyrolysis obtained multiple times in historical data. In an embodiment of the present invention, the preset content ratio of calcium-based inorganic matter in kitchen waste is set to 50% to 60%, and the preset content ratio of calcium-based inorganic matter in industrial solid waste is set to 60% to 70%.

[0071] Step S3, feeding the pyrolyzed municipal solid waste into a vertical mill for grinding, wherein the feed rate and grinding roller pressure of the vertical mill are determined according to the main components of the municipal solid waste;

[0072] See also Figure 2 , which is a flow chart of determining the feeding rate and grinding roller pressure of a vertical mill according to an embodiment of the present invention; specifically, in step S3, determining the feeding rate and grinding roller pressure of the vertical mill according to the main components of the municipal solid waste includes:

[0073] Step S31, obtaining the hardness, average particle size and content ratio of the main components of the municipal solid waste;

[0074] Step S32: determining the feed rate and grinding roller pressure of the vertical mill according to the hardness, average particle size and content ratio of the main components of the municipal solid waste.

[0075] Specifically, the hardness of the main components of urban solid waste can be tested by a hardness tester, or a number of randomly selected fragments of the main components of urban solid waste can be scratched against standard hardness fragments (with known hardness) to evaluate the hardness of each fragment and take the average as the hardness of the main components of urban solid waste; the different particle sizes of the main components of urban solid waste can be determined by a screening test, and the average particle size can be determined based on the average of several particle sizes that account for 65% to 80%; the content of different elements in the main components of urban solid waste can be determined based on technologies such as X-ray fluorescence spectroscopy or inductive coupling.

[0076] It should be noted that those skilled in the art know that any method in the prior art that can determine the hardness, average particle size and content ratio of the main components of urban solid waste falls within the scope of protection of the present invention and will not be described in detail here.

[0077] See also Figure 3 , which is a flow chart of step S32 of an embodiment of the present invention; specifically, step S32 includes:

[0078] Step S321, determining the basic feeding rate and basic grinding roller pressure of the vertical mill according to the hardness and average particle size of the main components of the municipal solid waste;

[0079] Specifically, if the hardness of the main component of the urban solid waste is less than a preset hardness threshold, and the average particle size of the main component of the urban solid waste is less than a preset particle size threshold, the vertical mill performs grinding at a first feeding rate and a first grinding roller pressure;

[0080] If the hardness of the main component of the municipal solid waste is greater than a preset hardness threshold, and the average particle size of the main component of the municipal solid waste is greater than a preset particle size threshold, the vertical mill performs grinding at a second feeding rate and a second grinding roller pressure;

[0081] If the hardness of the main component of the municipal solid waste is greater than a preset hardness threshold, and the average particle size of the main component of the municipal solid waste is less than or equal to the preset particle size threshold, the vertical mill performs grinding at a first feeding rate and a second grinding roller pressure;

[0082] If the hardness of the main component of the municipal solid waste is less than or equal to the preset hardness threshold, and the average particle size of the main component of the municipal solid waste is greater than the preset particle size threshold, the vertical mill grinds the waste at the second feeding rate and the first grinding roller pressure;

[0083] Wherein, the first feeding rate is greater than the second feeding rate; the first grinding roller pressure is less than the second grinding roller pressure.

[0084] In practice, the actual implementer can set the preset hardness threshold and preset particle size threshold based on the actual situation or based on the minimum hardness value and average particle size of the ground municipal solid waste that have passed the qualification test in historical data. Generally, the preset hardness threshold is set to 3.5-4.5, the preset particle size threshold is set to 50μm-70μm, the first feed rate of the vertical mill is set to 5.5 tons / hour-7.0 tons / hour, the second feed rate is set to 4.0 tons / hour-5.0 tons / hour, the first grinding roller pressure is set to 500kN-600kN, and the second grinding roller pressure is set to 650kN-800kN.

[0085] Step S322: adjusting the feeding rate and grinding roller pressure of the vertical mill according to the content ratio of the main components of the municipal solid waste.

[0086] During implementation, if the content ratio of the main components of the urban solid waste is greater than the preset content ratio, the basic feeding rate is reduced and the basic grinding roller pressure is increased; if the content ratio of the main components of the urban solid waste is less than or equal to the preset content ratio, the basic feeding rate is increased and the basic grinding roller pressure is reduced; the reduction / increase ratio is determined according to the content ratio of the main components of the urban solid waste. Preferably, the reduction / increase ratio is set to 1 / 4 to 1 / 8 of the content ratio of the main components of the urban solid waste.

[0087] Specifically, the actual implementers can set the preset content ratio based on the actual situation or based on the content ratio of the main components of urban solid waste that have passed the qualification test in historical data.

[0088] The present invention determines the feeding rate and grinding roller pressure of the vertical mill by the hardness, average particle size and content ratio of the main components of urban solid waste, which can effectively improve the grinding efficiency and grinding accuracy.

[0089] Step S4, determining the grinding degree based on the particle size distribution of the ground municipal solid waste to determine whether to re-grind the municipal solid waste. If re-grinding is required, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding based on the grinding degree;

[0090] See also Figure 4 , which is a schematic diagram of a process for determining the degree of grinding according to an embodiment of the present invention; specifically, in step S4, determining the degree of grinding according to the particle size distribution of the ground municipal solid waste includes:

[0091] Step S41, determining a particle size characteristic value according to the particle size distribution of the ground municipal solid waste;

[0092] Step S42: determining the degree of grinding based on the particle size characteristic value and a preset degree of grinding comparison table.

[0093] It should be noted that those skilled in the art know that any method in the prior art that can determine the particle size distribution of municipal solid waste after grinding falls within the scope of protection of the present invention and will not be described in detail here.

[0094] During implementation, the particle size corresponding to the maximum particle size ratio is determined based on the particle size distribution of the municipal solid waste after grinding, and is used as the particle size characteristic value.

[0095] Specifically, the actual implementers can set a preset grinding degree comparison table based on the actual situation or the grinding degree of urban solid waste after passing the qualification test based on historical data. Several grinding degree levels can be set, and each level has a corresponding critical particle size characteristic value to determine the grinding degree. Among them, the critical particle size characteristic value corresponding to the highest grinding degree level is the smallest, and the critical particle size characteristic value corresponding to the lowest grinding degree level is the largest.

[0096] Specifically, the step S4 includes:

[0097] The grinding degree is compared with a preset grinding degree. If the grinding degree does not meet the preset grinding degree, the municipal solid waste is ground again.

[0098] During implementation, the actual implementer can set the preset grinding degree according to the actual situation or based on the preset grinding degree comparison table. Preferably, the preset grinding degree is set to a higher level of grinding degree in the preset grinding degree comparison table. For example, the preset grinding degree comparison table divides the grinding degree into 5 levels, level 1 is the lowest grinding degree, and level 5 is the highest grinding degree. The preset grinding degree can be set to level 4 / level 5.

[0099] The present invention can reduce the particle size of the urban solid waste by re-grinding the urban solid waste when the grinding degree does not meet the preset grinding degree, thereby improving the uniformity between the various components of the urban solid waste and thus improving the performance of the green cementitious material.

[0100] See also Figure 5 , which is a flow chart of determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to an embodiment of the present invention; specifically, in step S4, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the grinding degree includes:

[0101] Step S43, comparing the grinding degree with a preset grinding degree to determine a first comparison value; wherein the first comparison value is a ratio of the grinding degree to the preset grinding degree;

[0102] In implementation, the first comparison value is determined according to the ratio of the particle size characteristic value corresponding to the grinding degree (the particle size corresponding to the maximum particle size ratio determined by the particle size distribution) and the particle size characteristic value corresponding to the preset grinding degree.

[0103] Step S44: determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the first comparison value.

[0104] Specifically, the step S44 includes:

[0105] Determining the mill speed for re-grinding of the vertical mill according to the first comparison value and the initial mill speed;

[0106] In implementation, the mill speed of the vertical mill for re-grinding is calculated according to the product of the first comparison value and the initial mill speed.

[0107] Determining the grinding roller pressure for re-grinding of the vertical mill according to the first comparison value and the initial grinding roller pressure;

[0108] In implementation, the grinding roller pressure of the vertical mill for re-grinding is calculated according to the product of the first comparison value and the initial grinding roller pressure.

[0109] The initial mill speed is the mill speed during the initial grinding of the vertical mill; and the initial grinding roller pressure is the grinding roller pressure during the initial grinding of the vertical mill.

[0110] The present invention determines the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the grinding degree, and can further improve the grinding efficiency.

[0111] Step S5, uniformly mixing the ground municipal solid waste, correcting the content of the main components of the municipal solid waste according to the number of grinding times and the particle size distribution, and determining the addition ratio of the gelling additive based on the detected specific surface area of the municipal solid waste and the corrected content of the main components;

[0112] Specifically, in step S5, the correction of the content of the main components of the municipal solid waste according to the number of grinding times and the particle size distribution includes:

[0113] If the grinding times are greater than the preset grinding times and the particle size distribution does not conform to the preset particle size distribution, reducing the content of the main components of the municipal solid waste;

[0114] The reduction ratio is determined according to the ratio of the grinding times to the preset grinding times and the difference between the particle size distribution and the preset particle size distribution.

[0115] Specifically, the reduction ratio H = A / B;

[0116] Among them, A is the ratio of the grinding times to the preset grinding times; B is the difference between the particle size distribution and the preset particle size distribution.

[0117] During implementation, the actual implementers can set the preset grinding times according to the actual situation or the average number of grinding times of urban solid waste that has passed the qualification test based on historical data, and set the preset particle size distribution according to the actual situation or the particle size distribution of urban solid waste that has passed the qualification test based on historical data.

[0118] The present invention corrects the content of the main components of the urban solid waste according to the number of grinding times and the particle size distribution. If the number of grinding times is greater than the preset number of grinding times and the particle size distribution does not conform to the preset particle size distribution, it indicates that the main components of the urban solid waste are relatively hard and the content is relatively high. In this way, the content of the main components of the urban solid waste is reduced to improve the performance of the prepared green cementitious material.

[0119] Specifically, in step S5, determining the addition ratio of the gelling additive based on the detected specific surface area of the municipal solid waste and the corrected content of the main components includes:

[0120] If the content of the main component is greater than a preset content threshold, determining the addition ratio of the gelling additive according to the ratio of the corrected specific surface area of the municipal solid waste to the preset specific surface area;

[0121] Specifically, the ratio of the corrected specific surface area of the urban solid waste to the preset specific surface area is W1 / W2, and the addition ratio of the gelling additive is W1 / W2, that is, the corrected ratio of the mass of the urban solid waste to the mass of the gelling additive is W1 / W2.

[0122] If the content of the main component is less than or equal to a preset content threshold, the addition ratio of the gelling additive is determined according to the ratio of the content of the main component to the preset content threshold.

[0123] Specifically, the ratio of the corrected content of the main components of the urban solid waste to the preset content threshold is S1 / S2, and the addition ratio of the gelling additive is S1 / S2, that is, the corrected ratio of the mass of the urban solid waste to the mass of the gelling additive is S1 / S2.

[0124] In implementation, the actual implementers can set the preset content threshold value based on the actual situation or the average content value of the main components of urban solid waste that have passed the qualification test based on historical data. Generally, the preset content threshold value is set to 70% to 80% of the total mass of the urban solid waste; and the actual implementers can set the preset specific surface area based on the actual situation or the specific surface area of the main components of urban solid waste that have passed the qualification test based on historical data. Generally, the preset specific surface area is set to 350m 2 / kg~450m 2 / kg.

[0125] Specifically, the gelling additive may be sodium carboxymethyl cellulose, polyacrylic acid, sodium alginate, carboxymethyl starch, and the like.

[0126] The present invention determines the addition ratio of the gelling additive based on the detected specific surface area of the urban solid waste and the corrected content of the main component. If the content of the main component is relatively high, the difference between the content of the main component and other components of the urban solid waste is relatively large, and the content of the added gelling additive is mainly affected by the content of the main component, while the specific surface area is easily affected by the main component of the urban solid waste. If the content of the main component is relatively low, the difference between the content of the main component and other components of the urban solid waste is relatively small, the addition ratio of the gelling additive can be determined according to the content of the main component, which can improve the accuracy of the ratio and thus improve the performance of the prepared green gelling material.

[0127] Step S6: mixing the ground municipal solid waste with the gelling additive in proportion to prepare a green gelling material.

[0128] The present invention pyrolyzes crushed urban solid waste, which can reduce the volume and weight of the urban solid waste, facilitate subsequent processing, and thus improve preparation efficiency; and based on the composition and content of the pyrolysis gas generated during the pyrolysis process, the main components of the urban solid waste can be analyzed and determined, which facilitates subsequent proportioning, thereby improving the performance of the green cementitious material. Grinding the pyrolyzed urban solid waste can evenly mix the various components in the urban solid waste and help stimulate the activity of the various components in the urban solid waste, thereby improving the performance of the cementitious material. Correcting the content of the main components of the urban solid waste based on the number of grinding times and the particle size distribution, and determining the addition ratio of the gelling additive based on the detected specific surface area of the urban solid waste and the corrected content of the main components can effectively improve the performance and stability of the prepared green cementitious material.

[0129] Example 1:

[0130] This embodiment provides a gelling material prepared from municipal solid waste using the preparation method of the present invention. The municipal solid waste raw material comes from municipal kitchen solid waste. The content of the main components is obtained according to the method of the embodiment of the present invention. The ratio with the gelling additive and the tested gelling properties are shown in Table 1 below.

[0131] Example 2:

[0132] This embodiment provides a gelling material prepared from urban solid waste using the preparation method of the present invention. The urban solid waste raw material comes from urban industrial solid waste, and the content of the main components is obtained according to the method of the embodiment of the present invention. The ratio with the gelling additive and the tested gelling properties are shown in Table 1 below.

[0133] Example 3:

[0134] This embodiment provides a cementitious material prepared from municipal solid waste using the preparation method of the present invention. The municipal solid waste raw material is the same as that in Example 1 (crushed and homogenized into equal parts). The content of the main components was not analyzed. The ratio of the main components to the cementitious additives was based on a preset content threshold. The tested cementitious properties are shown in Table 1 below.

[0135] Example 4:

[0136] This example provides a cementitious material prepared from municipal solid waste using the preparation method of the present invention. The municipal solid waste raw material is the same as that in Example 2 (crushed and homogenized into equal parts). The content of the main components was not analyzed, and the ratio of the main components to the gelling additives was based on a preset content threshold. The tested gelling properties are shown in Table 1 below.

[0137] Table 1 Components and gelling effects

[0138]

[0139] Table 1 shows that the gelling properties of the gelling material prepared by the preparation method of the present invention are significantly better than those of the conventional preparation method. The higher the content of the main component (calcium-based inorganic matter) and the higher the addition ratio of the gelling additive, the better the gelling properties of the green gelling material prepared accordingly.

[0140] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A method for preparing green gelling materials based on waste resource utilization, characterized in that: include: Step S1, placing the crushed municipal solid waste into a pyrolysis reactor for pyrolysis, and determining the degree of pyrolysis based on the change in gas pressure in the pyrolysis reactor; Step S2: if the degree of pyrolysis meets the preset standard, separating the pyrolysis gas generated after pyrolysis, and determining the main components of the municipal solid waste based on the composition and content of the pyrolysis gas; the main components include calcium-based inorganic substances; Step S3, feeding the pyrolyzed municipal solid waste into a vertical mill for grinding, wherein the feed rate and grinding roller pressure of the vertical mill are determined according to the main components of the municipal solid waste; Step S4, determining the grinding degree based on the particle size distribution of the ground municipal solid waste to determine whether to re-grind the municipal solid waste. If re-grinding is required, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding based on the grinding degree; Step S5, uniformly mixing the ground municipal solid waste, correcting the content of the main components of the municipal solid waste according to the number of grinding times and the particle size distribution, and determining the addition ratio of the gelling additive based on the detected specific surface area of the municipal solid waste and the corrected content of the main components; Step S6: mixing the ground municipal solid waste with the gelling additive in proportion to prepare a green gelling material.

2. The method for preparing green gelling materials based on waste resource utilization according to claim 1, characterized in that: In step S1, determining the degree of pyrolysis according to the change in gas pressure in the pyrolysis reactor includes: The gas pressure in the pyrolysis reactor is continuously collected to determine the gas pressure ratio of each adjacent collection point, and the pyrolysis degree is determined according to each gas pressure ratio and a preset pyrolysis degree comparison table.

3. The method for preparing green gelling materials based on waste resource utilization according to claim 1, characterized in that: In step S3, determining the feed rate and grinding roller pressure of the vertical mill according to the main components of the municipal solid waste includes: Step S31, obtaining the hardness, average particle size and content ratio of the main components of the municipal solid waste; Step S32: determining the feed rate and grinding roller pressure of the vertical mill according to the hardness, average particle size and content ratio of the main components of the municipal solid waste.

4. The method for preparing green gelling materials based on waste resource utilization according to claim 3, characterized in that: The step S32 includes: Step S321, determining the basic feeding rate and basic grinding roller pressure of the vertical mill according to the hardness and average particle size of the main components of the municipal solid waste; Step S322: adjusting the feeding rate and grinding roller pressure of the vertical mill according to the content ratio of the main components of the municipal solid waste.

5. The method for preparing green gelling materials based on waste resource utilization according to claim 4, characterized in that: In step S4, determining the degree of grinding according to the particle size distribution of the ground municipal solid waste includes: Step S41, determining a particle size characteristic value according to the particle size distribution of the ground municipal solid waste; Step S42: determining the degree of grinding based on the particle size characteristic value and a preset degree of grinding comparison table.

6. The method for preparing green gelling materials based on waste resource utilization according to claim 5, characterized in that: In the step S4, it includes: The grinding degree is compared with a preset grinding degree. If the grinding degree does not meet the preset grinding degree, the municipal solid waste is ground again.

7. The method for preparing green gelling materials based on waste resource utilization according to claim 6, characterized in that: In step S4, determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the grinding degree includes: Step S43, comparing the grinding degree with a preset grinding degree to determine a first comparison value; wherein the first comparison value is a ratio of the grinding degree to the preset grinding degree; Step S44: determining the mill speed and grinding roller pressure of the vertical mill for re-grinding according to the first comparison value.

8. The method for preparing green gelling materials based on waste resource utilization according to claim 7, characterized in that: In the step S44, it includes: Determining the mill speed for re-grinding of the vertical mill according to the first comparison value and the initial mill speed; Determining the grinding roller pressure for re-grinding of the vertical mill according to the first comparison value and the initial grinding roller pressure; The initial mill speed is the mill speed during the initial grinding of the vertical mill; and the initial grinding roller pressure is the grinding roller pressure during the initial grinding of the vertical mill.

9. The method for preparing green gelling materials based on waste resource utilization according to claim 8, characterized in that: In step S5, the correction of the content of the main components of the municipal solid waste according to the number of grinding times and the particle size distribution includes: If the grinding times are greater than the preset grinding times and the particle size distribution does not conform to the preset particle size distribution, reducing the content of the main components of the municipal solid waste; The reduction ratio is determined according to the ratio of the grinding times to the preset grinding times and the difference between the particle size distribution and the preset particle size distribution.

10. The method for preparing green gelling materials based on waste resource utilization according to claim 9, characterized in that: In step S5, determining the addition ratio of the gelling additive based on the detected specific surface area of the municipal solid waste and the corrected content of the main components includes: If the content of the main component is greater than a preset content threshold, determining the addition ratio of the gelling additive according to the ratio of the corrected specific surface area of the municipal solid waste to the preset specific surface area; If the content of the main component is less than or equal to a preset content threshold, the addition ratio of the gelling additive is determined according to the ratio of the content of the main component to the preset content threshold.

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