A method for cold pressing blast furnace gravity ash

Abstract

The present invention discloses a method for cold-pressing blast furnace gravity ash, comprising the steps of: (1) drying blast furnace gravity ash and converter steel slag tailings; (2) preparing a binder; (3) spraying water and mixing blast furnace gravity ash, converter tailings and binder at a mass ratio of 80:20:15-35, and pressing into blocks to prepare a sample. The present invention treats blast furnace gravity ash by adding a high-efficiency binder and converter tailings to make it cold-pressed. CMC in the binder is used to perform low-temperature consolidation on converter tailings and blast furnace gravity ash, and cement and bentonite are used to improve their strength, thereby finally achieving effective bonding of blast furnace gravity ash, expanding its application path, and providing a new method for treating blast furnace gravity ash, a solid waste resource of enterprises.

Description

Technical Field

[0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a method for cold pressing blast furnace gravity ash. Background Art

[0002] Blast furnace gravity ash is a carbon-rich industrial by-product with a carbon content of about 40%. This characteristic gives it excellent reducing ability. In the reduction modification process, the application prospects of blast furnace gravity ash have attracted much attention, especially as a converter slag modifier; its high carbon content helps to improve the strength of converter slag, increase the proportion of cementitious active materials in the slag and the iron recovery rate, thereby expanding the comprehensive utilization of converter slag. In addition, the silicon, calcium and other elements contained in blast furnace gravity ash play a positive role in regulating the basicity of converter slag and realizing the natural pulverization of converter slag by relying on the transformation of dicalcium silicate crystal form.

[0003] Despite this, blast furnace gravity ash still faces challenges in its application. Its large particle size and good hydrophilicity make it difficult to shape, which affects its application in industrial production.

[0004] Based on the physical and chemical properties of blast furnace gravity ash, the present invention designs a special binder rich in cohesiveness and gelling activity to achieve efficient and environmentally friendly utilization of blast furnace gravity ash. The special binder can not only significantly improve the molding performance of blast furnace gravity ash through scientific formulation, but also improve its mechanical strength and durability. In practical applications, the binder can be widely used in the fields of brick making and ball making of blast furnace gravity ash, providing a new solution for the resource utilization of industrial waste. Summary of the invention

[0005] The present invention uses blast furnace gravity ash as the main raw material, converter tailings as aggregate (particle size 5-10mm), and special binder as molding material. After cold pressing, it falls 1.5m (3 times) to the surface of the steel plate without falling apart. After drying, the compressive strength is higher than 5MPa, which meets the transportation and storage requirements and realizes the effective utilization of solid waste resources. In order to achieve the purpose of the present invention, the following technical scheme is proposed: Its process flow is as follows: Figure 1 shown.

[0006] One aspect of the present invention relates to a method for cold pressing blast furnace gravity ash, comprising the following steps:

[0007] (1) drying blast furnace gravity ash and converter steel slag tailings, wherein the blast furnace gravity ash contains C, TFe (full iron), CaO, SiO2, MgO and Al2O3, and the C and TFe contents thereof are between 40-50% and 20-30%, respectively;

[0008] (2) preparing a binder, the binder comprising sodium carboxymethyl cellulose (CMC), bentonite and cement, wherein the mass ratio of sodium carboxymethyl cellulose (CMC), bentonite and cement is 8-12:8-12:8-12 (preferably 1:1:1);

[0009] (3) Mix blast furnace gravity ash, converter tailings, and binder in a mixer at a mass ratio of 80-100:20-30:15-35; spray water and continue stirring until the end, the stirring time is 8-12 minutes;

[0010] (4) taking out the raw material and molding it in the mold using a pressure of 8-20 MPa to simulate the on-site process without pressure maintenance during the molding process;

[0011] (5) Strength test: test the drop strength of the wet sample (dropped 3 times at a height of 1.5 m). Dry the wet sample in a drying oven at 105°C and test the strength of the dry sample. The strength is greater than 7 MPa.

[0012] In a preferred embodiment of the present invention, the compressive strength of blast furnace gravity ash briquette is 10.03-15.37 MPa.

[0013] In a preferred embodiment of the present invention, step (3) is to mix blast furnace gravity ash, converter tailings, and binder in a mass ratio of 80:20:30 and a water content of 35%, and mix them in a mixer. A press is used to prepare a standard block using step (4), and a sample is obtained through step (5).

[0014] In a preferred embodiment of the present invention, the dry sample strength is tested, and the average compressive strength is higher than 7.00 MPa, preferably higher than 10.00 MPa, preferably higher than 12.00 MPa, and particularly preferably higher than 13.00 MPa.

[0015] In a preferred embodiment of the present invention, the water content is tested. The average water content is 17.59%, preferably 16.75%, and particularly preferably 14.76%.

[0016] In a preferred embodiment of the present invention, the drying temperature of the drying oven is 100-110° C., preferably 105° C., and the drying time is 120 min.

[0017] The idea of ​​the present invention is based on the blast furnace gravity ash briquetting treatment technology, adding metallurgical solid waste converter tailings as aggregate structure, and preparing samples by adding special binders. CMC in the binder is used to perform low-temperature consolidation of aggregates and blast furnace gravity ash, and cement and bentonite are used to improve the strength of the dry sample, ultimately achieving effective bonding of blast furnace gravity ash, expanding its application path, and providing a new method for the treatment of blast furnace gravity ash, a solid waste resource of enterprises.

[0018] The invention utilizes a high-efficiency binder to bond blast furnace gravity ash, expands its efficient utilization path through a consolidation mechanism, and solves the problem that blast furnace gravity ash is difficult to shape and cannot be efficiently utilized.

[0019] The present invention is applied to the tempering and modification of converter slag and the iron recovery stage, fundamentally solving the technical bottleneck problem of efficient recycling of bulk metallurgical solid waste.

[0020] The present invention takes a unique approach and utilizes residual carbon (blast furnace gravity ash) after high temperature and applies it to the processing process of converter slag, thereby increasing the reaction time of reduction and modification of converter slag, while consuming the difficult-to-process blast furnace solid waste resource gravity ash, thereby achieving the goal of synergistic processing of waste treatment with waste and complementary advantages.

[0021] The experimental schemes adopted in the present invention all adopt the existing briquetting process. In industrial experimental research, only the existing briquetting process needs to be reasonably utilized without any additional supplement. The blast furnace gravity ash can be effectively utilized to modify the steel slag, and the resource recycling of the steel slag can be realized, which has a reference significance for establishing an integrated steel slag process.

[0022] The invention determines the optimal ratio scheme of blast furnace gravity ash-binder by adjusting the ratio of binder and water content. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0024] In the attached picture: Figure 1 The flowchart of the blast furnace gravity ash cold pressing process of the present invention is shown.

[0025] Figure 2 FIG. 1 shows an embodiment of the present invention.

[0026] Figure 3 FIG. 2 shows an embodiment of the present invention.

[0027] Figure 4 FIG. 3 shows an embodiment of the present invention.

[0028] Figure 5 FIG. 4 shows an embodiment of the present invention.

[0029] Figure 6 FIG. 5 shows an embodiment of the present invention.

[0030] Figure 7 FIG. 6 shows an embodiment of the present invention.

[0031] Figure 8 FIG. 7 shows an embodiment of the present invention.

[0032] Fig. 9 FIG8 shows an embodiment of the present invention.

[0033] Fig.10 FIG. 9 shows an embodiment of the present invention.

[0034] Fig.11 FIG. 10 shows an embodiment of the present invention.

[0035] Fig.12 FIG. 11 shows an embodiment of the present invention.

[0036] Fig.13 FIG. 12 shows an embodiment of the present invention.

[0037] Fig.14 FIG. 13 shows an embodiment of the present invention.

[0038] Fig.15 FIG. 14 shows an embodiment of the present invention.

[0039] Fig.16 FIG15 shows an embodiment of the present invention.

[0040] Fig.17 FIG. 16 shows an embodiment of the present invention.

[0041] Fig.18 FIG. 17 shows an embodiment of the present invention.

[0042] Fig.19 FIG. 18 shows an embodiment of the present invention.

[0043] Fig. 20 A standard sample diagram of the present invention is shown. DETAILED DESCRIPTION

[0044] The present invention will be further described with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0045] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0046] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are commercially available products unless otherwise specified. Example 1

[0047] A method for cold-pressing blast furnace gravity ash, wherein the raw material formula of the cold-pressing blast furnace gravity ash comprises, by weight, 80g of blast furnace gravity ash, 20g of converter tailings, 40g of water and 15g of a binder. Figure 2shown.

[0048] The blast furnace gravity ash cold pressing molding of the present invention comprises the following steps during production:

[0049] Preparation of binder: The main components of the binder are sodium carboxymethyl cellulose (CMC), bentonite and cement, which are mixed in a ratio of 1:1:1. The ratio in the present invention is based on mass.

[0050] Mixing of raw materials: Mix blast furnace gravity ash, converter tailings and binder in a mixer at a mass ratio of 80:20:15; measure a certain amount of water, with a moisture content of 40g, and continue stirring until the end, with a stirring time of 8 to 12 minutes.

[0051] Sample preparation: In a standard mold (61 41mm) was formed using a pressure of 15MPa to simulate the on-site process, and no pressure holding treatment was performed during the molding process.

[0052] Strength test: Test the falling strength of wet samples (drop 3 times at 1.5m), dry the wet samples in a drying oven at 105℃, and test the strength of the dry samples. Example 2

[0053] The difference from Example 1 is the binder ratio. The blast furnace gravity ash cold pressing molding raw material formula includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 20g binder. Figure 3 shown. Example 3

[0054] The difference from Example 1 is the binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 25g binder. Figure 4 shown. Example 4

[0055] The difference from Example 1 is the water content and the binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 25g binder. Figure 5 shown. Example 5

[0056] The difference from Example 1 is the water content and the binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 30g binder. Figure 6 shown. Example 6

[0057] The difference from Example 1 is the water content and the binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 35g binder. Figure 7 shown. Example 7

[0058] The difference from Example 1 is the binder ratio. The raw material formula for cold-pressing blast furnace gravity ash includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 15g binder (5g CMC and 10g bentonite). Figure 8 shown. Example 8

[0059] The difference from Example 1 is the binder ratio. The raw material formula for cold-pressing blast furnace gravity ash includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 15g binder (5g CMC and 10g cement). Fig. 9 shown. Example 9

[0060] The difference from Example 1 is the binder ratio. The raw material formula for cold-pressing blast furnace gravity ash includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 20g binder (6.67g CMC and 13.33g bentonite). Fig.10 shown. Example 10

[0061] The difference from Example 1 is the binder ratio. The raw material formula for cold-pressing blast furnace gravity ash includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 20g binder (6.67g CMC and 13.33g cement). Fig.11 shown. Embodiment 11

[0062] The difference from Example 1 is the binder ratio. The raw material formula for cold-pressing blast furnace gravity ash includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 25g binder (8.34g CMC and 16.66g bentonite). Fig.12 shown. Example 12

[0063] The difference from Example 1 is the binder ratio. The raw material formula for cold-pressing blast furnace gravity ash includes: 80g blast furnace gravity ash, 20g converter tailings, 40g water and 25g binder (8.34g CMC and 16.66g cement). Fig.13 shown. Embodiment 13

[0064] The difference from Example 1 is the moisture content and binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 25g binder (8.34g CMC and 16.66g bentonite). Fig.14 shown. Embodiment 14

[0065] The difference from Example 1 is the moisture content and binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 25g binder (8.34g CMC and 16.66g cement). Fig.15 shown. Embodiment 15

[0066] The difference from Example 1 is the moisture content and binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 30g binder (10g CMC and 20g bentonite). Fig.16 shown. Example 16

[0067] The difference from Example 1 is the moisture content and binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 30g binder (10g CMC and 20g cement). Fig.17 shown. Embodiment 17

[0068] The difference from Example 1 is the moisture content and binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 35g binder (11.67g CMC and 23.33g bentonite). Fig.18 shown. Embodiment 18

[0069] The difference from Example 1 is the moisture content and binder ratio. The raw material formula of the blast furnace gravity ash cold pressing molding includes: 80g blast furnace gravity ash, 20g converter tailings, 35g water and 35g binder (11.67g CMC and 23.33g cement). Fig.19 shown.

[0070] The specific formula data of 18 groups of embodiments of the present invention are shown in Table 1

[0071] Table 1 Example formulation data and compressive strength of dried samples

[0072]

[0073] Note: The compressive strength test direction is Fig. 20 (b) Direction.

[0074] It should be noted that the inventors also conducted the following test: the difference from Example 6 is that the binder is 36.3g (12.10g CMC, 12.10g bentonite and 12.10g cement), and its compressive strength is not better than that of Example 6.

[0075] Blast furnace gravity ash is difficult to pelletize and has high processing costs, making it difficult to handle directly.

[0076] In order to solve these problems, blast furnace gravity ash is processed into products of specific shapes through cold pressing process. This technology not only expands the utilization of blast furnace gravity ash and realizes efficient recycling, but also reduces production costs and reduces the burden on the environment.

[0077] The method for cold-pressing blast furnace gravity ash of the present invention comprises the following steps: mixing blast furnace gravity ash, converter tailings, a special binder and water in a certain ratio and pressing them into shape. The method has low preparation cost, makes full use of solid waste resources, reduces environmental pollution caused by resource accumulation, and plays the role of energy conservation, environmental protection and resource recycling.

[0078] The product prepared by cold-pressing blast furnace gravity ash of the present invention can be applied to the high-temperature reduction modification process of converter slag, reduce the strength of converter slag, improve the enrichment of cementitious materials, and achieve the goal of reducing costs and increasing efficiency.

[0079] Through the above-mentioned embodiments, the advantages of the present invention are:

[0080] It makes full use of solid waste resources such as blast furnace gravity ash and converter tailings, avoiding waste of resources and environmental pollution.

[0081] By adding special binders and water, the molding properties of the mixture are improved, making the molded products have higher strength and stability.

[0082] The cold pressing process is simple, easy to operate, and does not require high-temperature heating, thus reducing the preparation cost.

[0083] The molded products can be widely used in metal smelting, metallurgical slag reduction and modification treatment processes and other fields, and have good market prospects.

[0084] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for cold pressing blast furnace gravity ash, characterized in that: The steps include: (1) drying blast furnace gravity ash and converter steel slag tailings, wherein the blast furnace gravity ash contains C, TFe, CaO, SiO2, MgO and Al2O3, wherein the C and TFe contents are between 40-50% and 20-30%, respectively, and the converter steel slag tailings are used as aggregate structure; (2) preparing a binder, wherein the binder mainly comprises sodium carboxymethyl cellulose, bentonite and cement, and the ratio of the three by mass is 8-12:8-12:8-12; (3) stirring and mixing blast furnace gravity ash, converter steel slag tailings, and binder in a mass ratio of 80-100:20-30:15-35; spraying water and continuing stirring until the end, the stirring time is 8-12 minutes; (4) Take out the raw material and shape it in a mold using a pressure of 8~20MPa.

2. The method according to claim 1, characterized in that The step (3) is to mix the blast furnace gravity ash, the converter steel slag tailings and the binder in a mass ratio of 80:20:

30.

3. The method according to claim 2, characterized in that The step (4) is performed by molding the product in a standard mold using a pressure of 12-18 MPa.

4. The method according to claim 1 or 2, characterized in that: The method also includes step (5) of drying the sample.

5. The method according to claim 4, characterized in that The drying temperature of the drying is 100-110°C.

6. The method according to claim 4, characterized in that The method also includes testing the compressive strength of the dry sample, wherein the compressive strength of the dry sample is greater than 7 MPa.

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