CN112213255B - Carbonization test method with adjustable carbon dioxide concentration - Google Patents
Carbonization test method with adjustable carbon dioxide concentration Download PDFInfo
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- CN112213255B CN112213255B CN202011114416.8A CN202011114416A CN112213255B CN 112213255 B CN112213255 B CN 112213255B CN 202011114416 A CN202011114416 A CN 202011114416A CN 112213255 B CN112213255 B CN 112213255B
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- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims abstract description 208
- 239000001569 carbon dioxide Substances 0.000 title claims abstract description 104
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims abstract description 104
- 238000003763 carbonization Methods 0.000 title claims abstract description 54
- 238000010998 test method Methods 0.000 title claims abstract description 16
- 239000007789 gas Substances 0.000 claims abstract description 71
- 239000002689 soil Substances 0.000 claims abstract description 42
- 238000000034 method Methods 0.000 claims abstract description 28
- 239000000463 material Substances 0.000 claims abstract description 24
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000004567 concrete Substances 0.000 claims abstract description 7
- 239000000523 sample Substances 0.000 claims description 97
- 230000001105 regulatory effect Effects 0.000 claims description 35
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 20
- 239000003570 air Substances 0.000 claims description 19
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 10
- 239000000292 calcium oxide Substances 0.000 claims description 10
- 235000012255 calcium oxide Nutrition 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 8
- 239000011398 Portland cement Substances 0.000 claims description 7
- 239000004816 latex Substances 0.000 claims description 7
- 229920000126 latex Polymers 0.000 claims description 7
- 238000012423 maintenance Methods 0.000 claims description 7
- 229910052734 helium Inorganic materials 0.000 claims description 5
- 239000001307 helium Substances 0.000 claims description 5
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 5
- 239000004570 mortar (masonry) Substances 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- 230000009471 action Effects 0.000 claims description 4
- 239000012670 alkaline solution Substances 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 14
- 239000000395 magnesium oxide Substances 0.000 abstract description 13
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 abstract description 13
- 238000007711 solidification Methods 0.000 abstract description 12
- 230000008023 solidification Effects 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 10
- 238000009423 ventilation Methods 0.000 abstract description 7
- 230000009286 beneficial effect Effects 0.000 abstract description 4
- 230000008859 change Effects 0.000 abstract description 4
- 238000002955 isolation Methods 0.000 abstract description 3
- 230000008878 coupling Effects 0.000 abstract 1
- 238000010168 coupling process Methods 0.000 abstract 1
- 238000005859 coupling reaction Methods 0.000 abstract 1
- 238000009434 installation Methods 0.000 abstract 1
- 230000001737 promoting effect Effects 0.000 abstract 1
- 238000001723 curing Methods 0.000 description 17
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 8
- 238000010276 construction Methods 0.000 description 8
- NEKPCAYWQWRBHN-UHFFFAOYSA-L magnesium;carbonate;trihydrate Chemical group O.O.O.[Mg+2].[O-]C([O-])=O NEKPCAYWQWRBHN-UHFFFAOYSA-L 0.000 description 6
- 238000002156 mixing Methods 0.000 description 6
- 238000010000 carbonizing Methods 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 239000002585 base Substances 0.000 description 4
- 229910000019 calcium carbonate Inorganic materials 0.000 description 4
- 239000004568 cement Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 239000003513 alkali Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 230000000813 microbial effect Effects 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000005056 compaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- QRGVJYFZZFSGAK-UHFFFAOYSA-N C(=O)=O.[O-2].[Mg+2] Chemical compound C(=O)=O.[O-2].[Mg+2] QRGVJYFZZFSGAK-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000011066 ex-situ storage Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000003469 silicate cement Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D11/00—Control of flow ratio
- G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
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- General Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
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- General Health & Medical Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Ecology (AREA)
- Biochemistry (AREA)
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- Biodiversity & Conservation Biology (AREA)
- Immunology (AREA)
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- Automation & Control Theory (AREA)
- Treating Waste Gases (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention discloses a carbonization test method with adjustable carbon dioxide concentration, which comprises the steps of sample installation to be carbonized, carbon dioxide concentration adjustment, sample confining pressure application, air inlet pressure application, sample carbonization, tail gas treatment and the like. The method comprises the steps of sequentially introducing carbon dioxide and another non-reactive gas into a pressure-bearing barrel, and adjusting the ratio of the inlet pressure of the two gases to realize the automatic adjustment of the concentration of the carbon dioxide; the carbon dioxide gas is squeezed into the gas inlet pipe through the expansion effect of the isolation air bag, so that the problem that the traditional concrete carbonization box can only change the concentration of the carbon dioxide but can not change the pressure at the same time is solved; the confining pressure is applied by adopting air pressure instead of water pressure, so that the influence of the heat conduction and the permeation of the water body on the sample carbonization is avoided. The test method is beneficial to solving the coupling influence of the carbon dioxide concentration and the ventilation pressure on the carbonization and solidification effects of the soil body, and has important significance for promoting the effective application of low-concentration carbon dioxide gas in the magnesium oxide solidification material.
Description
Technical Field
The invention belongs to a test method of civil engineering instruments, and particularly relates to a carbonization test method with adjustable carbon dioxide concentration.
Background
With the development of economy and urbanization, the foundation construction of urban construction, traffic and water conservancy and the like often meets soft soil layers or liquefied silt soil layers with different thicknesses, and the soil has the poor characteristics of low strength, high compressibility, large pore ratio, high water content and the like, so that great challenges are brought to engineering construction. The mechanical strength and stability of the weak soil or sandy soil are required to be improved by manual improvement treatment so as to meet the requirements of engineering construction. The traditional method for treating weak soil or silt soil is divided into physical treatment, chemical curing treatment and microbial curing treatment. Physical treatment methods such as a backfill method, a prepressing tamping method, a sludge heat treatment method and the like are adopted, but the traditional backfill method is rarely recommended to be used in a large area due to the defects of large engineering quantity, difficult material taking and stacking, high cost and the like; the dynamic compaction method and the vibroflotation method are also limited in use in many projects due to large construction noise, high energy consumption and the like; the heat treatment method is a method for converting sludge into building materials by a heating or sintering method, and has small treatment capacity, high cost and difficult large-scale utilization; the sedimentation, airing or mud throwing treatment occupies a large amount of stacking sites, the land occupied by the mud is difficult to be reused in a short time, the construction cost is increased, and secondary pollution of air, water, soil and the like is easily caused in the process of pumping drainage or ex-situ landfill. Microbial solidification is a novel soil solidification technology, microbial liquid and nutrient solution additives are sprayed in soil by a certain means, so that the growth of a cementing material and the cementation of soil particles are realized, but the technology has high cost and long period, has high requirements on the activity and survival conditions of microbes, is not beneficial to large-area popularization, and is more suitable for sandy soil or silt with higher porosity. For this reason, the chemical curing method is the most widely used technique due to its simple curing agent, easy construction and high curing strength, such as cement/lime pile, grouting method, high pressure jet grouting pile, etc., and the curing materials used in the conventional chemical curing method are mainly cement and lime. However, the traditional chemical curing method has long treatment and maintenance period, and the used material cement has large energy resource consumption and serious environmental pollution in the production process, thereby bringing a plurality of negative effects on the sustainable development of economy and environment.
In recent years, geotechnical workers have begun to explore cement substitute materials and corresponding curing methods, and the inventors have conducted a great deal of research and have disclosed a series of inventions: for example, "a method for carbonizing and solidifying soil (201210097042.2)", "a method for carbonizing and solidifying soil and a device thereof (201010604013.1)", "a treatment system and a method for thermally consolidating soft soil foundation using industrial waste gas (201310122135.0)", "a treatment system and a method for carbonizing and piling up soil (2014102039788)", "a method for carbonizing and solidifying a filling-up pad layer of a soft soil foundation (2014102729571)", "a treatment method for in-situ carbonizing and solidifying a shallow soft foundation (201510348797.9)", and "a composite foundation of a carbonized stirring pile and a gas-permeable tubular pile and a construction method thereof (201710225231.6)", which are soft soil treatment techniques disclosed based on a magnesium oxide-carbon dioxide carbonization mechanism. In addition, the existing research or patent of the invention adopts commercial high-purity carbon dioxide gas, and although the carbonization and solidification of soil can be well realized, the cost of the commercial high-purity carbon dioxide gas is high, and the carbonization technology is difficult to popularize and apply.
In order to promote the application of low-concentration carbon dioxide gas in soil carbonization and solidification, the influence of the concentration of the carbon dioxide on the carbonization performance of a carbonized alkaline material solidified soil sample needs to be researched, the mutual relation among the concentration of the carbon dioxide, ventilation pressure and ventilation time is researched, and the influence rule of the concentration of the carbon dioxide on the soil carbonization and solidification effect is determined. Although some concrete carbonization chambers can regulate the concentration of carbon dioxide, the regulation principle of the concentration of carbon dioxide is as follows: under the same air pressure, the concentration of carbon dioxide in the sealed box is adjusted by setting the flow ratio of the carbon dioxide to air; and the gas pressure of the carbonization box is low, and the pressure can not be adjusted, so that the research on the carbonization effect of carbon dioxide concentration, ventilation pressure and carbonization time is greatly limited. Based on the advantages of the carbonization strengthening method, in combination with the current situation that the influence of the concentration of carbon dioxide on the carbonization and solidification effect is unknown, a carbonization test method with adjustable concentration of carbon dioxide is urgently needed to be researched and developed, has important significance for realizing the effective application of different concentrations of carbon dioxide in the carbonization and solidification of soil, and is beneficial to the popularization and application of the carbonization technology in the solidification of soil.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a carbonization test method with adjustable carbon dioxide concentration, and the test method has important significance for solving the influence rule of the carbon dioxide concentration on the carbonization and solidification effect of a sample and realizing the effective application of different carbon dioxide concentrations in the carbonization and solidification sample.
In order to achieve the aim, the invention discloses a carbonization test method with adjustable carbon dioxide concentration, which is characterized by comprising the following steps:
a. installing a sample to be carbonized: opening the top cover of the pressure chamber, aligning the lower vent plate with the lower temperature probe and placing on the base, then placing the sample on the lower vent plate, sheathing the latex film on the outer side of the sample, then sequentially placing the upper vent plate and the top seat on the sample, tightly hooping the latex film on the outer sides of the base and the top seat, finally covering the top cover, screwing the screw cap of the pull rod, connecting the temperature probe and opening the acquisition instrument and the computer,
b. adjusting the concentration of carbon dioxide: opening a control valve A and adjusting a pressure reducing valve A to a pressure P1 to enable high-concentration carbon dioxide to enter a pressure-bearing barrel and reach a stable pressure P1; then closing the control valve A and the pressure reducing valve A, opening the control valve B and adjusting the pressure reducing valve B to pressure P2, leading the gas in the high-pressure gas tank to enter the pressure-bearing barrel and be mixed with the carbon dioxide in the pressure-bearing barrel to form low-concentration carbon dioxide, finally closing the control valve B and the pressure reducing valve B when the gas pressure is stabilized at P2,
c. applying confining pressure of a pressure chamber: starting the air compressor, closing the control valve E and the pressure regulating valve A, opening the control valve C, regulating the pressure regulating valve B to pressure P3,
d. applying ventilation pressure: closing the control valve F, opening and regulating the pressure regulating valve C to make the reading of the barometer be P4, simultaneously closing the control valve D, opening and regulating the pressure regulating valve A to pressure P5 to make the isolating airbag gradually bulge to press the low-concentration carbon dioxide gas in the pressure-bearing barrel to make the low-concentration carbon dioxide enter the sample according to the pressure of P4,
e. sample carbonization: the sample is carbonized and maintained under the action of confining pressure P3 and air inlet pressure P4, the temperatures of the bottom and the top of the sample are automatically monitored in the carbonization process, when the temperature of the top is higher than or equal to the temperature of the bottom, the pressure regulating valve C can be automatically adjusted to be small or closed,
f. and finishing maintenance: when the temperature of the top of the sample begins to decrease, the maintenance is stopped, the control valve C, the pressure regulating valve A, the pressure regulating valve B and the pressure regulating valve C are closed in sequence, then the control valve D, the control valve E and the control valve F are opened in sequence, the air in the pressure chamber is discharged, and the residual carbon dioxide gas in the sample and the pipeline is discharged into the alkaline solution tank.
As a modification of the invention, the sample is a compacted sample doped with an alkaline material, the alkaline material is a mixture of active magnesium oxide, quicklime or portland cement, the active magnesium oxide comprises 20-100%, the quicklime comprises 10-40%, and the portland cement comprises 0-30%, and the compacted sample can be soil, polluted soil, concrete or mortar.
As a modification of the present invention, the mixture of carbon dioxide and gas in the high-pressure gas tank satisfies an ideal gas state equation, and under the same pressure, the volume ratio of carbon dioxide to the volume of the mixed gas is the volume concentration of carbon dioxide, and the concentration is equal to P1: p2, wherein the concentration range of the low-concentration carbon dioxide is 0-100%.
As a modification of the invention, the pressure P2 is less than the limit pressure of the pressure-bearing barrel, the pressure P2 is greater than or equal to the pressure P1, the pressure P4 is greater than or equal to the pressure P3, and the pressure P5 is greater than or equal to the pressure P4; the pressure P1 was determined to be 1.5 times or more the amount of carbon dioxide required to fully carbonize the sample.
As another modification of the invention, the gas in the high-pressure gas tank does not react with the carbon dioxide, the sample and the curing agent, and can be nitrogen, helium or air.
Compared with the prior art, the invention has the beneficial effects that:
1) the pressure-bearing barrel which is pre-filled with carbon dioxide gas with certain pressure and high concentration is filled with another gas, the adjustment of the carbon dioxide concentration is realized by adjusting the pressure of the other gas, the adjustment method is simple and easy to implement, and the influence of different carbon dioxide concentrations on the sample carbonization effect can be favorably researched.
2) On the premise of not influencing the gas capacity of the pressure-bearing barrel, the carbon dioxide gas can be extruded into the gas inlet pipe by the expansion pressure of the isolation airbag, and the problem that the traditional concrete carbonization box can only change the concentration of the carbon dioxide but can not change the pressure at the same time is solved.
3) The sample is mixed with a certain proportion of alkaline material such as active magnesium oxide, and the magnesium oxide is carbonized under the action of low-concentration carbon dioxide, so that the strength of the sample is promoted to be increased.
4) The confining pressure is applied to the sample in the pressure chamber in a gas form, the hydraulic confining pressure form adopted in the traditional triaxial chamber is changed, and the influence of water heat conduction and permeation on sample carbonization is avoided.
5) The outside of the carbonization chamber is connected with the lye tank, so that the residual carbon dioxide in the sampling and sample changing process is absorbed, and the environmental pollution is avoided.
Drawings
FIG. 1 is a schematic structural diagram of a carbonization test device with adjustable carbon dioxide concentration;
in the figure: 1. a high-pressure gas tank, 2, a carbon dioxide high-pressure tank, 3, an air compressor, 4, a pressure regulating valve A, 5, a three-way joint, 6, a pressure regulating valve B, 7, a barometer B, 8, a pressure regulating valve C, 9, a barometer C, 10, a quick connector A, 11, a quick connector B, 12, an acquisition instrument, 13, a computer, 14, a base, 15, a lower vent plate, 16, a lower temperature probe, 17, a sample, 18, a latex film, 19, a pressure chamber, 20, an upper vent plate, 21, an upper temperature probe, 22, a top seat, 23, a top cover, 24, a pull rod, 25, a quick connector C, 26, a quick connector D, 27, a quick connector E, 28, a control valve A, 29, a pressure reducing valve A, 30, a control valve B, 31, a pressure reducing valve B, 32, a control valve C, 33, a barometer A, 34, a quick connector F, 35, an isolation airbag, 36, an alkali barrel, 37, an electronic scale, 38 and a pressure-bearing liquid tank, 39. quick-connect joints G, 40, control valves D, 41, quick-connect joints H, 42, control valves E, 43 and control valve F.
Detailed Description
The invention discloses a carbonization test method with adjustable carbon dioxide concentration, which is characterized by comprising the following steps of:
a. installing a sample to be carbonized: opening a top cover 23 of the pressure chamber, aligning a lower vent plate 15 with a lower temperature probe 16 and placing the lower vent plate on a base 14, then placing a mixed soil compaction sample doped with an alkaline material on the lower vent plate 15, sleeving a latex film 18 on the outer side of the sample, sequentially placing an upper vent plate 20 and a top seat 22 on the sample, tightly hooping the latex film 18 on the outer sides of the base 14 and the top seat 22, finally covering the top cover 23, screwing a screw cap of a pull rod 24, connecting the temperature probe, and opening an acquisition instrument 12 and a computer 13; the sample is a compacted sample doped with an alkaline material, the alkaline material can be a mixture of active magnesium oxide, quicklime or portland cement, the active magnesium oxide can account for 20-100%, the quicklime can account for 10-40%, the portland cement can account for 0-30%, the compacted sample can be a soil body, polluted soil, concrete or mortar,
b. adjusting the concentration of carbon dioxide: opening a control valve A28 and adjusting a pressure reducing valve A29 to a pressure P1 to enable carbon dioxide gas to enter a pressure-bearing barrel 36 and reach a stable pressure P1; then closing the control valve A28 and the pressure reducing valve A29, opening the control valve B30 and adjusting the pressure reducing valve B31 to a pressure P2, enabling the gas in the high-pressure gas tank 1 to enter the pressure-bearing barrel 36 to be mixed with the carbon dioxide gas in the pressure-bearing barrel 36, enabling the gas pressure to be stabilized at P2, and finally closing the control valve B30 and the pressure reducing valve B31; wherein, the gas in the high-pressure gas tank 1 does not react with the carbon dioxide, the sample and the curing agent and can be nitrogen, helium or air; the mixture of the carbon dioxide and the gas in the high-pressure gas tank 1 meets an ideal gas state equation, the volume ratio of the carbon dioxide to the mixed gas is the volume concentration of the carbon dioxide under the same pressure, the concentration is P1: P2, the concentration range is 0-100%, the pressure P2 is less than the limit pressure of the pressure-bearing barrel, the pressure P2 is more than or equal to the pressure P1, wherein the pressure P1 is determined by more than 1.5 times of the required carbon dioxide when the sample is completely carbonized,
c. pressure application chamber 19 confining pressure: starting air compressor 3, closing control valve E42 and pressure regulating valve A4, opening control valve C32, regulating pressure regulating valve B6 to pressure P3,
d. applying ventilation pressure: closing the control valve F43, opening and adjusting the pressure regulating valve C8 to make the barometer C9 read P4, wherein the pressure P4 is greater than or equal to the pressure P3; meanwhile, the control valve D40 is closed, the pressure regulating valve A4 is opened and regulated to pressure P5, the isolating air bag is enabled to be gradually expanded, the low-concentration carbon dioxide gas in the pressure-bearing barrel 36 is squeezed, wherein the pressure P5 is more than or equal to P4, the low-concentration carbon dioxide gas enters the sample according to the pressure P4,
e. sample carbonization: the sample is carbonized and maintained under the action of confining pressure P3 and air inlet pressure P4, the temperatures of the bottom and the top of the sample are automatically monitored in the carbonization process, when the temperature of the top is higher than or equal to the temperature of the bottom, the pressure regulating valve C8 can be automatically reduced or closed,
f. and finishing maintenance: when the temperature of the top of the sample starts to decrease, the maintenance is stopped, the control valve C32, the pressure regulating valve A4, the pressure regulating valve B6 and the pressure regulating valve C8 are closed in sequence, then the control valve D40, the control valve E42 and the control valve F43 are opened in sequence, the air in the pressure chamber 19 is discharged, and the residual carbon dioxide gas in the sample and the pipeline is discharged to the lye tank 38.
Based on the above operation principle and steps, the calculation steps of the ventilation pressures P1 and P2 for obtaining high concentration carbon dioxide and high pressure gas, for example, using a soil sample: (1) calculating the total volume of the sample according to the size of the soil mass sample; (2) calculating the mass of dry soil in the soil sample according to the natural density and the initial water content of the soil body of the sample; (3) calculating the total amount of the alkaline material according to the percentage of the alkaline material; (4) under the condition of assuming that the sample is completely carbonized, calculating the amount of carbon dioxide required for the complete carbonization reaction according to a carbonization reaction equation; (5) calculating the carbon dioxide pressure corresponding to the amount of carbon dioxide required according to the ideal gas state equation PV ═ nRT (where P is the gas pressure, V is the volume, R is a constant, T is the temperature, and n is the amount of substance): (6) the value of the pressure P1 is determined from the pressure P1 as 1.5 times or more the amount of carbon dioxide required for complete carbonization of the sample: (7) the value of pressure P2 was determined from the carbon dioxide concentration required for the test and pressure P1.
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below by combining the figures.
Example 1:
if the sample is a cylinder with the diameter of 50mm and the height of 100mm, and the natural density of the soil body of the sample is 1.8g/cm3The initial water content is 20%, and the alkali material is 100% active magnesium oxide, and the mixing amount is 10%. Assuming that the sample is subjected to complete carbonization reaction and the product is magnesium carbonate trihydrate, the P1 is about 217kPa according to an ideal gas state equation and the pressure P1, wherein the pressure is 2 times of the required carbon dioxide when the sample is completely carbonized, and if the introduced high-pressure gas is nitrogen and the carbon dioxide is carbon dioxideWith a carbon concentration of 70%, P2 was about 310 kPa.
Example 2:
if the sample is a cylinder with a diameter of 50mm and a height of 100mm, and the density of the polluted soil of the sample is 1.85g/cm3The initial water content is 20%, and the alkali material is 100% active magnesium oxide, and the mixing amount is 10%. Assuming that the sample is subjected to complete carbonization reaction and the product is magnesium carbonate trihydrate, the P1 is about 218kPa according to an ideal gas state equation and the pressure P1, wherein the pressure is 2 times of the required carbon dioxide when the sample is completely carbonized, and if the introduced high-pressure gas is nitrogen and the carbon dioxide concentration is 70%, the P2 is about 312 kPa.
Example 3:
if the sample is a cylinder with a diameter of 50mm and a height of 100mm, and the density of the polluted soil of the sample is 1.8g/cm3The initial water content is 25%, and the alkaline curing agent is composed of 60% of active magnesium oxide and 40% of quicklime, and the mixing amount of the alkaline curing agent is 10%. Assuming that the sample is subjected to complete carbonization reaction and the products are magnesium carbonate trihydrate and calcium carbonate, the P1 is about 218kPa according to the ideal gas state equation and the pressure P1, which is 2 times of the amount of carbon dioxide required when the sample is completely carbonized, and if the high-pressure gas fed is helium and the concentration of carbon dioxide is 70%, the P2 is about 311 kPa.
Example 4:
if the sample is a cylinder with the diameter of 50mm and the height of 100mm, and the natural density of the soil body of the sample is 1.8g/cm3The initial water content is 20%, and the alkaline curing agent consists of 60% of active magnesium oxide and 40% of quicklime, and the mixing amount of the alkaline curing agent is 15%. Assuming that the sample is subjected to complete carbonization reaction and the products are magnesium carbonate trihydrate and calcium carbonate, the P1 is about 216kPa according to the ideal gas state equation and the pressure P1, which is 2 times of the amount of carbon dioxide required when the sample is completely carbonized, and if the high-pressure gas fed is helium and the concentration of carbon dioxide is 70%, the P2 is 309 kPa.
Example 5:
if the mortar sample is a cylinder with the diameter of 50mm and the height of 100mm, and the density of the mortar sample is 2.0g/cm3Initial water content of 20% and alkaliThe curing material consists of 60 percent of active magnesium oxide, 20 percent of quicklime and 20 percent of portland cement, and the mixing amount of the curing material is 10 percent. Assuming that the sample is subjected to complete carbonization reaction and the products are magnesium carbonate trihydrate (or other magnesium basic carbonates) and calcium carbonate, the P1 is about 218kPa determined according to the ideal gas state equation and the pressure P1 according to 2 times of the required carbon dioxide amount when the sample is completely carbonized, and if the high-pressure gas is selected to be air and the carbon dioxide concentration is 50%, the P2 is about 436 kPa.
Example 6:
if the sample is a cylinder with the diameter of 50mm and the height of 100mm, and the natural density of the soil body of the sample is 1.8g/cm3The initial water content is 20%, the alkaline solidifying material is composed of alkaline material selected from 60% of active magnesium oxide, 20% of quicklime and 20% of silicate cement, and the mixing amount is 15%. Assuming that the sample is subjected to complete carbonization reaction and the products are magnesium carbonate trihydrate and calcium carbonate, the P1 is about 163kPa according to the ideal gas state equation and the pressure P1, which is 1.5 times of the amount of carbon dioxide required when the sample is completely carbonized, and if the high-pressure gas is selected to be air and the concentration of carbon dioxide is 70%, the P2 is about 233 kPa.
Comparing example 1, example 2, example 3, example 4, example 5 and example 6, it can be seen that when the apparatus is used to perform carbonization test with adjustable carbon dioxide concentration, the aeration pressure of carbon dioxide and high-pressure gas can be adjusted in real time according to the type of the sample (concrete is not shown in the examples because the sample size is small), the initial water content, the doping amount of alkaline material and the required carbon dioxide concentration, so as to ensure that sufficient carbon dioxide can completely carbonize the sample on the basis of reaching the carbon dioxide concentration required by the test.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited by the foregoing examples, which are provided to illustrate the principles of the invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention, which is also intended to be covered by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (5)
1. A carbonization test method with adjustable carbon dioxide concentration is characterized by comprising the following steps:
a. installing a sample to be carbonized: opening the top cover of the pressure chamber, aligning the lower vent plate with the lower temperature probe and placing on the base, then placing the sample on the lower vent plate, sheathing the latex film on the outer side of the sample, then sequentially placing the upper vent plate and the top seat on the sample, tightly hooping the latex film on the outer sides of the base and the top seat, finally covering the top cover, screwing the screw cap of the pull rod, connecting the temperature probe and opening the acquisition instrument and the computer,
b. adjusting the concentration of carbon dioxide: opening a control valve A and adjusting a pressure reducing valve A to a pressure P1 to enable high-concentration carbon dioxide to enter a pressure-bearing barrel and reach a stable pressure P1; then closing the control valve A and the pressure reducing valve A, opening the control valve B and adjusting the pressure reducing valve B to pressure P2, leading the gas in the high-pressure gas tank to enter the pressure-bearing barrel and be mixed with the carbon dioxide in the pressure-bearing barrel to form low-concentration carbon dioxide, finally closing the control valve B and the pressure reducing valve B when the gas pressure is stabilized at P2,
c. applying confining pressure of a pressure chamber: starting the air compressor, closing the control valve E and the pressure regulating valve A, opening the control valve C, regulating the pressure regulating valve B to pressure P3,
d. applying intake pressure: closing the control valve F, opening and regulating the pressure regulating valve C to make the reading of the barometer be P4, simultaneously closing the control valve D, opening and regulating the pressure regulating valve A to pressure P5 to make the isolating airbag gradually bulge to press the low-concentration carbon dioxide gas in the pressure-bearing barrel to make the low-concentration carbon dioxide enter the sample according to the pressure of P4,
e. sample carbonization: the sample is carbonized and maintained under the action of confining pressure P3 and air inlet pressure P4, the temperatures of the bottom and the top of the sample are automatically monitored in the carbonization process, when the temperature of the top is higher than or equal to the temperature of the bottom, the pressure regulating valve C can be automatically adjusted to be small or closed,
f. and finishing maintenance: when the temperature of the top of the sample begins to decrease, the maintenance is stopped, the control valve C, the pressure regulating valve A, the pressure regulating valve B and the pressure regulating valve C are closed in sequence, then the control valve D, the control valve E and the control valve F are opened in sequence, the air in the pressure chamber is discharged, and the residual carbon dioxide gas in the sample and the pipeline is discharged into the alkaline solution tank.
2. The carbonization test method with adjustable carbon dioxide concentration as claimed in claim 1, wherein the sample is a compacted sample doped with an alkaline material, the alkaline material is a mixture of activated magnesium oxide, quicklime or portland cement, the composition of the activated magnesium oxide is 20-100%, the composition of the quicklime is 10-40%, and the composition of the portland cement is 0-30%, and the compacted sample can be soil, polluted soil, concrete or mortar.
3. The carbonization test method with adjustable carbon dioxide concentration as claimed in claim 1, wherein the mixture of carbon dioxide and gas in the high-pressure gas tank satisfies the ideal gas equation of state, the volume ratio of carbon dioxide to the volume of the mixed gas is the volume concentration of carbon dioxide at the same pressure, the concentration is equal to P1: P2, and the concentration of the low-concentration carbon dioxide is in the range of 0-100%.
4. The carbonization test method with adjustable carbon dioxide concentration as claimed in claim 1, wherein the pressure P2 is less than the limit pressure of the pressure-bearing barrel, the pressure P2 is greater than or equal to the pressure P1, the pressure P4 is greater than or equal to the pressure P3, the pressure P5 is greater than or equal to the pressure P4, and the pressure P1 is determined by more than 1.5 times of the required carbon dioxide amount when the sample is completely carbonized.
5. The carbonization test method with adjustable carbon dioxide concentration according to claim 1, wherein the gas in the high-pressure gas tank does not react with the carbon dioxide, the sample and the curing agent, and can be nitrogen, helium or air.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091173A (en) * | 2013-01-14 | 2013-05-08 | 桂林理工大学 | Triaxial test apparatus of soil under water-soil chemical action and method thereof |
| CN107389398A (en) * | 2017-06-30 | 2017-11-24 | 武汉大学 | A kind of adjustable soil sample instrument for carbonizing of confined pressure |
| CN108844888A (en) * | 2018-08-10 | 2018-11-20 | 清华大学 | A kind of scale pressure carbonization device and method after industrial solid wastes basification |
| CN109612899A (en) * | 2018-11-19 | 2019-04-12 | 中国矿业大学 | A kind of pressure correction formula gas permeability calculation method |
| CN110044792A (en) * | 2019-04-25 | 2019-07-23 | 合肥工业大学 | A kind of multi-functional low permeability media gas permeability test device and test method |
| CN110726822A (en) * | 2019-10-21 | 2020-01-24 | 南京林业大学 | Method for testing expansibility and shear strength of carbonized soil in carbonization process of magnesium oxide solidified soil |
| CN111610309A (en) * | 2020-05-07 | 2020-09-01 | 上海大学 | Device for testing gas adsorption capacity and oxidation efficiency of soil body with controllable soil body external load |
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Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091173A (en) * | 2013-01-14 | 2013-05-08 | 桂林理工大学 | Triaxial test apparatus of soil under water-soil chemical action and method thereof |
| CN107389398A (en) * | 2017-06-30 | 2017-11-24 | 武汉大学 | A kind of adjustable soil sample instrument for carbonizing of confined pressure |
| CN108844888A (en) * | 2018-08-10 | 2018-11-20 | 清华大学 | A kind of scale pressure carbonization device and method after industrial solid wastes basification |
| CN109612899A (en) * | 2018-11-19 | 2019-04-12 | 中国矿业大学 | A kind of pressure correction formula gas permeability calculation method |
| CN110044792A (en) * | 2019-04-25 | 2019-07-23 | 合肥工业大学 | A kind of multi-functional low permeability media gas permeability test device and test method |
| CN110726822A (en) * | 2019-10-21 | 2020-01-24 | 南京林业大学 | Method for testing expansibility and shear strength of carbonized soil in carbonization process of magnesium oxide solidified soil |
| CN111610309A (en) * | 2020-05-07 | 2020-09-01 | 上海大学 | Device for testing gas adsorption capacity and oxidation efficiency of soil body with controllable soil body external load |
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