Low-carbon cement and method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud

Abstract

The present invention relates to a low-carbon cement and a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and belongs to the technical field of low-carbon cement. In order to solve the problem of resource utilization of printing and dyeing sludge and papermaking white mud, the present invention provides a low-carbon cement and a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud. The raw materials of the low-carbon cement in the present invention include calcined powder of printing and dyeing sludge, dry powder of papermaking white mud and ordinary Portland cement. The present invention reduces the amount of traditional cement used in the concrete preparation process by adding printing and dyeing sludge and papermaking white mud to traditional cement, and carries out reduction, resource utilization and green treatment of printing and dyeing sludge and papermaking white mud. At the same time, printing and dyeing sludge participates in the gelling reaction due to its high aluminum characteristics to generate dense C‑A‑S‑H gel, thereby improving the mechanical strength and durability of the final product. The low-carbon cement and its preparation method provided by the present invention have broad application prospects in the field of building materials, especially in the field of low-carbon building materials.

Description

Technical Field

[0001] The invention belongs to the technical field of low-carbon cement, and in particular relates to low-carbon cement and a method for preparing the low-carbon cement by using printing and dyeing sludge and papermaking white mud. Background Art

[0002] The cement industry is one of the main sources of carbon emissions. According to statistics, cement production accounts for about 5-7% of global carbon dioxide emissions. This is mainly because the calcination of limestone in the cement production process releases a large amount of carbon dioxide. In addition, the high-temperature combustion in the cement production process also consumes a lot of energy, which further increases its environmental footprint. Therefore, finding alternative raw materials to reduce carbon emissions during the calcination process has become a key direction of technological reform in the industry.

[0003] With the strengthening of environmental protection regulations and the promotion of resource recycling, the treatment of industrial waste has attracted widespread attention. Printing and dyeing sludge and papermaking mud are two typical industrial solid wastes. Printing and dyeing sludge comes from the wastewater treatment process of the textile printing and dyeing industry, and contains a large amount of organic dyes, auxiliaries and other chemicals. Papermaking mud mainly comes from the deinking and bleaching process in the papermaking process, and its main components include calcium carbonate and a small amount of organic matter. If these wastes are not properly treated, they will cause serious pollution to the environment.

[0004] Using printing and dyeing sludge and papermaking mud in cement preparation can be used as a way to recycle these wastes and reduce the environmental burden of these wastes. However, the complex composition of printing and dyeing sludge and papermaking mud will affect the physical and chemical properties of cement. Therefore, how to synergistically utilize printing and dyeing sludge and papermaking mud to prepare low-carbon cement, realize the resource utilization of industrial waste and meet the physical and chemical properties of cement is an urgent problem to be solved in this field. Summary of the invention

[0005] In order to solve the problem of resource utilization of printing and dyeing sludge and papermaking white mud, the present invention provides a low-carbon cement and a method for preparing the low-carbon cement using the printing and dyeing sludge and papermaking white mud.

[0006] The technical solution of the present invention:

[0007] A low-carbon cement comprises the following raw materials by weight: 5-20 parts of calcined powder of printing and dyeing sludge, 5-15 parts of dried powder of papermaking white mud and 70-90 parts of ordinary Portland cement.

[0008] Furthermore, the raw materials include, by weight: 5 parts of calcined powder of printing and dyeing sludge, 5 parts of dried powder of papermaking white mud and 90 parts of ordinary Portland cement.

[0009] Furthermore, the ordinary Portland cement is P·O52.5 Portland cement.

[0010] A method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud comprises the following steps:

[0011] Step 1, grinding and sieving the printing and dyeing sludge after high-temperature calcination, and collecting the sieve to obtain the printing and dyeing sludge calcined powder;

[0012] Step 2, grinding and sieving the dried papermaking white mud, and collecting the sieved material to obtain the papermaking white mud dry powder;

[0013] Step 3: Mix 70 to 90 parts of ordinary Portland cement, 5 to 20 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 5 to 15 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0014] Furthermore, the calcination temperature in step 1 is 600° C. for 2 h, the heating rate is 10° C. / min, and the screening is through a 200-mesh sieve.

[0015] Furthermore, the main components of the printing and dyeing sludge calcined powder obtained in step 1 include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0016] Furthermore, in step 2, the drying temperature is 105° C. for 24 hours, and the sieving is through a 200-mesh sieve.

[0017] Furthermore, the main component of the papermaking white mud dry powder obtained in step 2 includes 93.6wt% CaO.

[0018] Furthermore, the ordinary Portland cement in step 3 is P·O52.5 Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0019] Furthermore, when the low carbon cement obtained in step 3 is used, 36 parts of a polycarboxylate water-reducing agent mixture are added to every 100 parts of the low carbon cement, and the polycarboxylate water-reducing agent mixture consists of 1 part of a polycarboxylate water-reducing agent and 35 parts of water.

[0020] Beneficial effects of the present invention:

[0021] The present invention reduces the usage of traditional cement in the process of concrete preparation by adding printing and dyeing sludge and papermaking white mud into traditional cement, reduces the amount of solid waste such as printing and dyeing sludge and papermaking white mud which are difficult to recycle, and disposes them in a green way, thereby obtaining a low-carbon cement with a strength not lower than that of traditional cement.

[0022] The invention utilizes the high alkalinity of papermaking white mud to neutralize the acidic substances in printing and dyeing sludge, thereby improving the performance of cement; at the same time, the printing and dyeing sludge participates in the gelling reaction by virtue of its high aluminum property to generate dense CASH gel, which can improve the later compressive strength of cement-based materials, improve the mechanical strength and durability of the final product, and make it have broad application prospects in the field of building materials, especially in the field of low-carbon building materials.

[0023] The present invention synergistically utilizes printing and dyeing sludge and papermaking white mud to prepare low-carbon cement, which can not only realize the resource utilization of industrial waste and reduce the cost of industrial waste treatment, but also reduce the cost of cement raw materials and improve production efficiency and economic benefits; at the same time, it also provides a sustainable material option for the construction industry, conforms to the global trend of environmental protection and sustainable development, and helps promote the green transformation of the construction materials industry. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below in conjunction with the embodiments, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically specified, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0025] Example 1

[0026] This embodiment provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0027] The printing and dyeing sludge used in this embodiment is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0028] The specific method of preparing low carbon cement from printing and dyeing sludge and papermaking white mud in this embodiment comprises the following steps:

[0029] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0030] Step 2: Place the papermaking white mud in an electric oven at 105° C. and dry for 24 hours, then grind it with a vibration mill for 3 minutes and pass it through a 200-mesh sieve. Collect the sieve-through material to obtain papermaking white mud dry powder. The main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO.

[0031] Step 3: Mix 90 parts of ordinary Portland cement, 5 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 5 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0032] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of the low-carbon cement prepared in this example, add 36 parts of the polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5°C and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing is completed, the compressive strength of the cement test block is tested.

[0033] Example 2

[0034] This embodiment provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0035] The printing and dyeing sludge used in this embodiment is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0036] The specific method of preparing low carbon cement from printing and dyeing sludge and papermaking white mud in this embodiment comprises the following steps:

[0037] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0038] Step 2: Place the papermaking white mud in an electric oven at 105° C. and dry for 24 hours, then grind it with a vibration mill for 3 minutes and pass it through a 200-mesh sieve. Collect the sieve-through material to obtain papermaking white mud dry powder. The main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO.

[0039] Step 3: Mix 85 parts of ordinary Portland cement, 10 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 5 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0040] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of the low-carbon cement prepared in this example, add 36 parts of the polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5°C and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing is completed, the compressive strength of the cement test block is tested.

[0041] Example 3

[0042] This embodiment provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0043] The printing and dyeing sludge used in this embodiment is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0044] The specific method of preparing low carbon cement from printing and dyeing sludge and papermaking white mud in this embodiment comprises the following steps:

[0045] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0046] Step 2: Place the papermaking white mud in an electric oven at 105° C. and dry for 24 hours, then grind it with a vibration mill for 3 minutes and pass it through a 200-mesh sieve. Collect the sieve-through material to obtain papermaking white mud dry powder. The main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO.

[0047] Step 3: Mix 80 parts of ordinary Portland cement, 10 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 10 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0048] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of the low-carbon cement prepared in this example, add 36 parts of the polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5°C and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing is completed, the compressive strength of the cement test block is tested.

[0049] Example 4

[0050] This embodiment provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0051] The printing and dyeing sludge used in this embodiment is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0052] The specific method of preparing low carbon cement from printing and dyeing sludge and papermaking white mud in this embodiment comprises the following steps:

[0053] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0054] Step 3: Mix 75 parts of ordinary Portland cement, 10 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 15 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0055] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of the low-carbon cement prepared in this example, add 36 parts of the polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5°C and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing is completed, the compressive strength of the cement test block is tested.

[0056] Example 5

[0057] This embodiment provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0058] The printing and dyeing sludge used in this embodiment is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0059] The specific method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud in this embodiment comprises the following steps:

[0060] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0061] Step 2: Place the papermaking white mud in an electric oven at 105° C. and dry for 24 hours, then grind it with a vibration mill for 3 minutes and pass it through a 200-mesh sieve. Collect the sieve-through material to obtain papermaking white mud dry powder. The main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO.

[0062] Step 3: Mix 80 parts of ordinary Portland cement, 15 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 5 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0063] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of low-carbon cement prepared in this comparative example, add 36 parts of polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5℃ and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing, test the compressive strength of the cement test block.

[0064] Example 6

[0065] This embodiment provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0066] The printing and dyeing sludge used in this embodiment is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0067] The specific method of preparing low carbon cement from printing and dyeing sludge and papermaking white mud in this embodiment comprises the following steps:

[0068] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0069] Step 2: Place the papermaking white mud in an electric oven at 105° C. and dry for 24 hours, then grind it with a vibration mill for 3 minutes and pass it through a 200-mesh sieve. Collect the sieve-through material to obtain papermaking white mud dry powder. The main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO.

[0070] Step 3: Mix 70 parts of ordinary Portland cement, 20 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 10 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0071] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of low-carbon cement prepared in this comparative example, add 36 parts of polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5℃ and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing, test the compressive strength of the cement test block.

[0072] Comparative Example 1

[0073] This comparative example provides an ordinary Portland cement test block, in which the cement used is P·O52.5 ordinary Portland cement, and its main components include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0074] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of P·O52.5 ordinary Portland cement, add 36 parts of polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface with a film, place it in a curing room with a temperature of 20±5℃ and a relative humidity of 90%, and demold it after 1 day to obtain an ordinary Portland cement test block. Continue to cure the obtained ordinary Portland cement test block in the curing room for 3d, 7d and 28d. After the curing, test the compressive strength of the cement test block.

[0075] Comparative Example 2

[0076] This comparative example provides a method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, and the prepared low-carbon cement.

[0077] The printing and dyeing sludge used in this comparative example is sludge from the textile printing and dyeing industry, the papermaking white mud is a by-product of the papermaking industry, and the cement is P·O52.5 ordinary Portland cement, the main components of which include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

[0078] The specific method for preparing low carbon cement from printing and dyeing sludge and papermaking white mud in this comparative example comprises the following steps:

[0079] Step 1: The printing and dyeing sludge is placed in a muffle furnace and calcined at 600°C for 2 hours, then ground with a vibration mill for 3 minutes and passed through a 200-mesh sieve. The sieve-through material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2.

[0080] Step 2: Place the papermaking white mud in an electric oven at 105° C. and dry for 24 hours, then grind it with a vibration mill for 3 minutes and pass it through a 200-mesh sieve. Collect the sieve-through material to obtain papermaking white mud dry powder. The main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO.

[0081] Step 3: Mix 60 parts of ordinary Portland cement, 30 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 10 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

[0082] Prepare a polycarboxylate water-reducing agent mixed solution consisting of 1 part of polycarboxylate water-reducing agent and 35 parts of water by weight, take 100 parts of low-carbon cement prepared in this comparative example, add 36 parts of polycarboxylate water-reducing agent mixed solution and mix evenly to obtain a mixed slurry, and test the fluidity of the obtained mixed slurry; pour the obtained mixed slurry into a mold, place it on a vibration table for vibration, smooth it, cover the surface, place it in a curing room with a temperature of 20±5℃ and a relative humidity of 90%, and demold it after 1 day to obtain a low-carbon cement test block. Continue to cure the obtained low-carbon cement test block in the curing room for 3d, 7d and 28d. After the curing, test the compressive strength of the cement test block.

[0083] The fluidity of cement mortar was measured for each group of examples according to the method specified in GB / T 2419-2005, and the compressive strength of cement mortar specimens was tested according to the method specified in GB / T17671-2001. The fluidity test results of the mixed slurries obtained in Examples 1-6 and Comparative Examples 1-2 and the compressive strength test results of the cement test blocks are shown in Table 1.

[0084] Table 1

[0085]

[0086] The results show that the large amount of printing and dyeing sludge and papermaking white mud has an adverse effect on the strength of low-carbon cement, especially in the early stages. However, the appropriate amount of printing and dyeing sludge and papermaking white mud can improve the later strength of low-carbon cement. The strength of ordinary Portland cement in Comparative Example 1 develops rapidly and stably, and the strength reaches 41.2MPa, 53.9MPa and 63.7MPa after curing for 3, 7 and 28 days. When the dosage of printing and dyeing sludge and papermaking white mud in Example 1 is 5%, the compressive strength of the low-carbon cement test block at 28 days of curing is higher than that of Comparative Example 1, reaching 65.2MPa. This is because the calcined printing and dyeing sludge has volcanic ash activity, which reacts with silicate to generate more CASH gel. At the same time. Due to the small particle size of printing and dyeing sludge, a denser microstructure can be formed.

Claims

1. A low carbon cement, characterized in that: The raw materials include, by weight: 5 parts of calcined powder of printing and dyeing sludge, 5 parts of dry powder of papermaking white mud and 90 parts of ordinary Portland cement; the main components of the calcined powder of printing and dyeing sludge include 31.42wt% of Al2O3, 11.97wt% of Fe2O3 and 10.23wt% of SiO2; the main components of the dry powder of papermaking white mud include 93.6wt% of CaO.

2. A low carbon cement according to claim 1, characterized in that: The ordinary Portland cement is P·O52.5 Portland cement.

3. A method for preparing low-carbon cement using printing and dyeing sludge and papermaking white mud, characterized in that: The steps include: Step 1: After high-temperature calcination, the printing and dyeing sludge is ground and sieved, and the sieved material is collected to obtain the printing and dyeing sludge calcined powder. The main components of the obtained printing and dyeing sludge calcined powder include 31.42wt% Al2O3, 11.97wt% Fe2O3 and 10.23wt% SiO2; Step 2: After drying, the papermaking white mud is ground and sieved, and the sieved material is collected to obtain a papermaking white mud dry powder, wherein the main component of the obtained papermaking white mud dry powder includes 93.6wt% CaO; Step 3: Mix 90 parts of ordinary Portland cement, 5 parts of the calcined powder of the printing and dyeing sludge obtained in step 1, and 5 parts of the dry powder of the papermaking white mud obtained in step 2 to obtain low-carbon cement.

4. The method for preparing low carbon cement using printing and dyeing sludge and papermaking white mud according to claim 3, characterized in that: The calcination temperature in step 1 is 600° C. for 2 h, the heating rate is 10° C. / min, and the sieving is through a 200-mesh sieve.

5. The method for preparing low carbon cement using printing and dyeing sludge and papermaking white mud according to claim 4, characterized in that: The drying temperature in step 2 is 105° C. for 24 hours, and the sieving is through a 200-mesh sieve.

6. The method for preparing low carbon cement using printing and dyeing sludge and papermaking white mud according to claim 5, characterized in that: Step 3: The ordinary Portland cement is P·O52.5 Portland cement, and its main components include 60.2wt% CaO, 23.8wt% SiO2, 6.1wt% Al2O3 and 4.5wt% SiO3.

7. The method for preparing low carbon cement from printing and dyeing sludge and papermaking white mud according to claim 6, characterized in that: When the low carbon cement obtained in step 3 is used, 36 parts of a polycarboxylate water-reducing agent mixture is added to every 100 parts of the low carbon cement, and the polycarboxylate water-reducing agent mixture consists of 1 part of a polycarboxylate water-reducing agent and 35 parts of water.

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