Preparation method of green cementing material based on waste recycling

Abstract

The invention relates to the technical field of building materials, in particular to a method for preparing a green cementing material based on waste recycling, which comprises the following steps: putting crushed urban solid waste into a pyrolysis reactor for pyrolysis, if the pyrolysis degree meets a preset standard, separating pyrolysis gas generated after pyrolysis, determining the main components of the urban solid waste according to the components and content of the pyrolysis gas; the pyrolyzed urban solid waste is introduced into a vertical mill to be ground; the grinding degree is determined to judge whether the urban solid waste is ground again or not, and if the urban solid waste is ground again, the grinding machine rotating speed and the grinding roller pressure of re-grinding of the vertical grinding machine are determined according to the grinding degree; correcting the content of main components of the urban solid waste according to the grinding frequency and the particle size distribution, and determining the adding proportion of a gelling additive; and mixing the ground urban solid waste with a gelling additive in proportion to prepare the green gelling material. The preparation method can effectively improve the preparation efficiency of the green cementing material.

Description

Technical Field

[0001] The 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] Urban solid waste not only seriously pollutes soil, water and air, endangers human health, but also affects urban landscape and damages the city's image. Researchers have begun to explore the transformation of urban solid waste into valuable materials, such as cementitious materials. The preparation of cementitious materials from urban solid waste is an effective way to utilize resources and can transform urban solid waste into valuable building materials. With the emergence of new technologies and the improvement of environmental protection requirements, the technical requirements for the preparation of cementitious materials from urban solid waste are also constantly 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 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 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 object, the present invention provides a method for preparing a green cementitious material based on waste resource utilization, comprising:

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

[0008] Step S2, if the degree of pyrolysis meets the preset standard, the pyrolysis gas generated after pyrolysis is separated, and the main components of the urban solid waste are determined according to the composition and content of the pyrolysis gas; the main components include calcium-based inorganic substances;

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

[0010] Step S4, determining the grinding degree according to the particle size distribution of the ground urban solid waste to determine whether to grind the urban solid waste again, and if so, determining the mill speed and roller pressure of the vertical mill for grinding again according to the grinding degree;

[0011] Step S5, uniformly mixing the ground urban solid waste, correcting the content of the main components of the urban 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 urban solid waste and the corrected content of the main components;

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

[0013] Furthermore, in the 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] Further, in the step S3, the feeding rate and roller pressure of the vertical mill are determined according to the main components of the urban solid waste, including:

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

[0017] Step S32, determining the feeding 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 urban 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 urban 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 urban solid waste.

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

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

[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, and if the grinding degree does not meet the preset grinding degree, the urban solid waste is ground again.

[0026] Further, in the step S4, determining the mill speed and 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 of the vertical mill for re-grinding according to the first comparison value and the initial mill speed;

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

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

[0033] Furthermore, in the step S5, the content of the main components of the urban 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 urban 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 the step S5, the addition ratio of the gelling additive is determined based on the detected specific surface area of ​​the urban solid waste and the corrected content of the main components, including:

[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 urban solid waste to the preset specific surface area;

[0038] If the content of the main component is less than or equal to the 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 effect of the present invention is 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 the preparation efficiency; and according to 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 is convenient for subsequent proportioning, thereby improving the performance of the green cementitious material. Grinding the pyrolyzed urban solid waste can make the various components in the urban solid waste mix evenly, 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 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 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 the 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, so as to improve the uniformity between the components of the urban solid waste and thus improve the performance of the green cementitious material.

[0043] Furthermore, the present invention determines the mill speed and the 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 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, indicating that the main components of the urban solid waste are relatively hard and have a relatively high content, 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 cementitious materials based on waste resource utilization of the present invention;

[0046] Figure 2A schematic diagram of a process for determining a feed rate and a 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 the 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 present invention is a schematic diagram of a process for determining the mill speed and roller pressure of the vertical mill for re-grinding. 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 in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used 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 protection scope 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 drawings. This is merely 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] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In this embodiment, urban solid waste generally refers to various wastes generated in production and life, including: kitchen 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 of 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 urban solid waste into a pyrolysis reactor for pyrolysis, and determining the degree of pyrolysis according to the change of 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 the actual application process. 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 pressure changes in the pyrolysis process in the historical data according to the actual situation. Preferably, the pyrolysis degree can be divided into 3 to 5 levels, and each level corresponds to a critical gas pressure ratio. For example: the pyrolysis degree is 3 levels, level 1 is the initial stage of pyrolysis, and the corresponding critical gas pressure ratio is 2.5; level 2 is the middle stage of pyrolysis, and the corresponding critical gas pressure ratio is 2.0; level 3 is the end of pyrolysis, and the corresponding critical gas 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 gas pressure in the pyrolysis reactor. The gas pressure ratio is calculated based on the ratio of the gas pressure value collected at the current collection point to the gas 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, the pyrolysis gas generated after pyrolysis is separated, and the main components of the urban solid waste are determined according to 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, when the pyrolysis reaction is basically complete, usually corresponding to the late pyrolysis stage of the pyrolysis degree comparison table. The preset standard generally selects the minimum value of the gas pressure ratio range corresponding to the late pyrolysis stage.

[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 protection scope of the present invention and will not be described in detail here.

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

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

[0069] If the total content of methane and nitrogen in the unit volume (1 cubic meter) of urban solid waste is less than 40% to 50% of the total pyrolysis gas, the main substance in the urban solid waste is determined to be calcium-based, and the content of the main component (calcium-based inorganic matter) of the urban solid waste 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 solid waste can be calculated based on the average value of the calcium-based inorganic matter content ratio obtained by multiple component analysis of kitchen waste solid waste after pyrolysis 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 multiple component analysis of industrial solid waste after pyrolysis in historical data. In an embodiment of the present invention, the preset content ratio of calcium-based inorganic matter in kitchen waste solid 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 urban solid waste into a vertical mill for grinding, wherein the feed rate and roller pressure of the vertical mill are determined according to the main components of the urban solid waste;

[0072] See also Figure 2 As shown, it is a schematic diagram of a process for determining the feeding rate and grinding roller pressure of a vertical mill according to an embodiment of the present invention; specifically, in step S3, the feeding rate and grinding roller pressure of the vertical mill are determined according to the main components of the urban solid waste, including:

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

[0074] Step S32, determining the feeding 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 urban 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 with 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 screening tests, 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 protection scope of the present invention and will not be described in detail here.

[0077] See also Figure 3 As shown, it is a schematic diagram of the process 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 urban 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 urban solid waste is greater than a preset hardness threshold, and the average particle size of the main component of the urban 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 urban solid waste is greater than a preset hardness threshold, and the average particle size of the main component of the urban 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 urban solid waste is less than or equal to the preset hardness threshold, and the average particle size of the main component of the urban solid waste is greater than the preset particle size threshold, the vertical mill performs grinding at the second feeding rate and the first grinding roller pressure;

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

[0084] In implementation, the actual implementation personnel can set the preset hardness threshold and the preset particle size threshold according to the actual situation or based on the minimum hardness value and average particle size of the ground urban solid waste that have passed the qualification test in the 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 urban 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, and 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 according to 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 according to 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 according to the particle size distribution of the ground urban solid waste to determine whether to grind the urban solid waste again, and if so, determining the mill speed and roller pressure of the vertical mill for grinding again according to the grinding degree;

[0090] See also Figure 4 As shown, it is a schematic diagram of the process of determining the degree of grinding according to an embodiment of the present invention; specifically, in step S4, the degree of grinding is determined according to the particle size distribution of the ground urban solid waste, including:

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

[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 urban solid waste after grinding falls within the protection scope of the present invention and will not be described in detail herein.

[0094] In implementation, the particle size corresponding to the maximum particle size ratio is determined according to the particle size distribution of the urban 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 in historical data, and can set several grinding degree levels, and set a corresponding critical particle size characteristic value for each level to determine the grinding degree, among which 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, in step S4, it includes:

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

[0098] In implementation, the actual implementers 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, with level 1 being the lowest grinding degree and level 5 being 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, so as to improve the uniformity between the components of the urban solid waste and thus improve the performance of the green cementitious material.

[0100] See also Figure 5 As shown, it is a schematic diagram of a process of determining the mill speed and the 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 the 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, in step S44, it includes:

[0105] Determining the mill speed of the vertical mill for re-grinding 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 of the vertical mill for re-grinding 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] Wherein, the initial mill speed is the mill speed of the vertical mill during initial grinding; and the initial grinding roller pressure is the grinding roller pressure of the vertical mill during initial grinding.

[0110] The present invention determines the mill speed and the 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 urban solid waste, correcting the content of the main components of the urban 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 urban solid waste and the corrected content of the main components;

[0112] Specifically, in step S5, the content of the main components of the urban solid waste is corrected according to the number of grinding times and the particle size distribution, including:

[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 urban 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 number of grinding times to the preset number of 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 in 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 in 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 have a relatively high content. 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, the addition ratio of the gelling additive is determined based on the detected specific surface area of ​​the urban solid waste and the corrected content of the main components, including:

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

[0124] In implementation, the actual implementers can set the preset content threshold according to the actual situation or the average content of the main components of urban solid waste that have passed the qualification test in historical data. Generally, the preset content threshold 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 according to the actual situation or the specific surface area of ​​the main components of urban solid waste that have passed the qualification test in 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 components. 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, and 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, thereby improving the performance of the prepared green gelling material.

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

[0128] 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 the preparation efficiency; and according to 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 is convenient for subsequent proportioning, thereby improving the performance of the green cementitious material. Grinding the pyrolyzed urban solid waste can make the various components in the urban solid waste mix evenly, 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 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 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] Embodiment 1:

[0130] This embodiment provides a gelling material prepared from urban solid waste by the preparation method of the present invention. The urban solid waste raw material comes from urban 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 gelling properties tested are shown in Table 1 below.

[0131] Embodiment 2:

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

[0133] Embodiment 3:

[0134] In this embodiment, a cementitious material is provided which is prepared from urban solid waste by the preparation method of the present invention. The urban solid waste raw material is consistent with that in Example 1 (homogenized and divided into equal parts after crushing), the content of the main components is not analyzed, the ratio with the cementitious additive adopts the addition ratio of the main components with a preset content threshold and the cementitious additive, and the tested cementitious properties are shown in Table 1 below.

[0135] Embodiment 4:

[0136] In this embodiment, a cementitious material is provided which is prepared from urban solid waste by the preparation method of the present invention. The urban solid waste raw material is consistent with that in Example 2 (homogenized and divided into equal parts after crushing), the content of the main components is not analyzed, the ratio with the cementitious additive adopts the addition ratio of the main components with a preset content threshold and the cementitious additive, and the tested cementitious 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 common 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 corresponding green gelling material.

[0140] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

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

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

4. The method for preparing green cementitious materials based on waste resource utilization according to claim 3 is characterized in that: The step S32 comprises: 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 urban 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 urban solid waste.

5. The method for preparing green cementitious 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 urban solid waste includes: Step S41, determining a particle size characteristic value according to the particle size distribution of the urban solid waste after grinding; 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 cementitious 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, and if the grinding degree does not meet the preset grinding degree, the urban solid waste is ground again.

7. The method for preparing green cementitious materials based on waste resource utilization according to claim 6, characterized in that: In the step S4, the mill speed and roller pressure of the vertical mill for re-grinding are determined according to the grinding degree, including: 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 cementitious materials based on waste resource utilization according to claim 7, characterized in that: In the step S44, it includes: Determining the mill speed of the vertical mill for re-grinding according to the first comparison value and the initial mill speed; Determining the grinding roller pressure of the vertical mill for re-grinding according to the first comparison value and the initial grinding roller pressure; Wherein, the initial mill speed is the mill speed of the vertical mill during initial grinding; and the initial grinding roller pressure is the grinding roller pressure of the vertical mill during initial grinding.

9. The method for preparing green cementitious materials based on waste resource utilization according to claim 8, characterized in that: In the step S5, the content of the main components of the urban solid waste is corrected according to the grinding times and the particle size distribution, including: 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 urban 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 cementitious materials based on waste resource utilization according to claim 9, characterized in that: In step S5, the addition ratio of the gelling additive is determined based on the detected specific surface area of ​​the urban solid waste and the corrected content of the main components, including: 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 urban solid waste to the preset specific surface area; If the content of the main component is less than or equal to the 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.

Images