A method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection

Abstract

This invention discloses a method for co-processing automobile dismantling residue and titanium-containing waste catalyst in blast furnace injection, belonging to the field of solid waste resource utilization technology. The invention mixes zinc-containing automobile dismantling residue and titanium-containing waste catalyst, then uses the mixture to replace a portion of pulverized coal in blast furnace injection. More preferably, the zinc-containing automobile dismantling residue is first heated, melted, and centrifuged to obtain an upper light molten component and a lower heavy molten component. The titanium-containing waste catalyst is then added to the upper light molten component for melting and mixing. The resulting light and heavy molten components are then cooled, crushed, and used together in blast furnace injection. This invention, by co-processing zinc-containing automobile dismantling residue and titanium-containing waste catalyst and using them to replace a portion of pulverized coal as blast furnace injection fuel, facilitates the simultaneous resource utilization of automobile dismantling residue and titanium-containing waste catalyst, and avoids the harmful effects of zinc in the automobile dismantling residue on the blast furnace.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, and more specifically, relates to a method for blast furnace injection and co-processing of automobile dismantling residue and titanium-containing waste catalyst. Background Technology

[0002] Waste SCR denitrification catalysts, as a type of hazardous solid waste, can cause serious harm to the natural environment and human health if improperly stockpiled or disposed of, while also wasting resources (the main component is titanium oxide). Current policies impose strict requirements on the disposal of such waste SCR catalysts. Existing technologies for the recycling and treatment of waste SCR denitrification catalysts mainly include solidification / stabilization and chemical recycling. Solidification / stabilization can solve the current problem of where to place the waste catalysts, but it still poses a long-term pollution risk to the environment. Chemical recycling methods easily generate polluting waste liquids during implementation, and the process is complex and costly.

[0003] After a scrapped car is manually dismantled, there will be residues equivalent to 15%-25% of the car's total weight, known as automotive debris. This debris is mainly a mixture of fragments and powders of dozens of materials, including plastics, rubber, foam materials, paint, metal particles, fiber composites, cloth, sand, and wood chips. Its composition is quite complex, and these components are further contaminated by toxic and harmful substances such as fuel, lubricating grease, and heavy metals during the dismantling, crushing, and sorting processes. Therefore, further separating these waste mixtures to obtain recycled materials with the required purity is both economically and technically difficult.

[0004] A search revealed no reports on the co-processing of waste SCR denitrification catalysts with automotive dismantling residues. Such co-processing would be significant for promoting the resource utilization of metallurgical and industrial wastes and for achieving a circular economy. Summary of the Invention

[0005] The purpose of this invention is to provide a method for co-processing automobile dismantling residue and titanium-containing waste catalyst in blast furnace injection. By co-processing zinc-containing automobile dismantling residue and titanium-containing waste catalyst, and using them to replace part of the pulverized coal as fuel for blast furnace injection, it is beneficial to realize the simultaneous resource utilization of automobile crushing residue and titanium-containing waste catalyst, and can avoid the harmful effects of zinc in automobile crushing residue on blast furnace.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows: This invention provides a method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection. The zinc-containing automobile dismantling residue and titanium-containing waste catalyst are mixed and then used to replace part of the pulverized coal in blast furnace injection.

[0007] This invention mixes zinc-containing automobile dismantling residue with titanium-containing waste catalyst, which can then be used to replace part of the pulverized coal in blast furnace injection. This achieves synergistic resource utilization of automobile dismantling residue and titanium-containing waste catalyst, and is conducive to carbon emission reduction. At the same time, the large amount of titanium in the titanium-containing waste catalyst can be combined with the zinc in the automobile dismantling residue to form zinc titanate during blast furnace injection, thus avoiding the reduction and evaporation of zinc in the automobile dismantling residue in the blast furnace, which would otherwise harm the blast furnace.

[0008] Furthermore, the titanium-containing waste catalyst is an SCR denitrification catalyst (the titanium content in the SCR denitrification catalyst is usually 80%-85%). However, it should be noted that the titanium-containing waste catalyst of the present invention is not limited to SCR denitrification catalyst, and other titanium-containing waste catalysts can also be used, as long as they do not have other adverse effects or hazards on the blast furnace.

[0009] Furthermore, the total amount of zinc-containing automobile dismantling residue and titanium-containing waste catalyst added accounts for 20%-30% of the total blast furnace fuel (the total amount of zinc-containing automobile dismantling residue, titanium-containing waste catalyst and pulverized coal added), thereby maximizing the resource utilization of zinc-containing automobile dismantling residue and titanium-containing waste catalyst while ensuring the blast furnace's fuel heating requirements.

[0010] In one embodiment of the present invention, zinc-containing automobile dismantling residue and titanium-containing waste catalyst are crushed or ground and then physically mixed, and then used for blast furnace injection. This method is simple to operate and can directly utilize the zinc in the automobile dismantling residue to react with the titanium in the titanium-containing waste catalyst to generate zinc titanate, thereby preventing the zinc oxide in the automobile dismantling residue from being reduced and evaporated in the blast furnace, which would harm the blast furnace.

[0011] Furthermore, the mass ratio of the zinc-containing automotive dismantling residue to the titanium-containing waste catalyst is 1:0.3-0.7, thereby ensuring that the zinc in the automotive dismantling residue can react fully, but is not affected by this value. As a further preferred embodiment of the present invention, zinc-containing automobile dismantling residue is heated and melted, and mixed with titanium-containing waste catalyst. After cooling and granulation, it is used for blast furnace injection. This can, to some extent, solve the problem that the heavy and light components in automobile dismantling residue are prone to stratification when directly physically mixed and then injected into the blast furnace.

[0012] As a further preferred embodiment of the present invention, the zinc-containing automobile dismantling residue is first heated, melted, and centrifuged to obtain an upper light molten component and a lower heavy molten component; then, titanium-containing waste catalyst is added to the upper light molten component for mixing, and the final light molten component and heavy molten component are cooled, crushed, and then used together for blast furnace injection.

[0013] By adopting the above method, the following technical effects can be achieved simultaneously: 1) During blast furnace injection, zinc in automobile dismantling residue reacts with titanium in titanium-containing waste catalyst to generate zinc titanate, preventing zinc in automobile dismantling residue from causing harm to the blast furnace; 2) The molten organic matter in the upper light component solidifies and bonds the light fibers and other components in automobile dismantling residue, effectively solving the problem of poor rheological properties of the light fibers during blast furnace injection; 3) The density of the upper light component is adjusted by adding titanium-containing waste catalyst, thereby further preventing the stratification of the upper light component and the lower heavy component during blast furnace injection.

[0014] Furthermore, the amount of titanium-containing waste catalyst added is such that the density difference between the upper light component and the lower heavy component obtained after adding the waste catalyst is no greater than 0.3 g / cm³. 3 For reference only. Before adding titanium-containing waste catalyst, the density of the resulting upper light component is approximately 0.8-1.0 g / cm³. 3 The density of the lower layer of heavy components is approximately 1.5-1.7 g / cm³. 3 After adding spent catalyst, the density of the upper layer component was adjusted to make the density difference between the upper and lower layers less than 0.3 g / cm³. 3 This effectively prevents stratification during blast furnace injection.

[0015] Furthermore, the heating and melting temperature is 400-550℃, the centrifugation speed is 3000-4000 rpm, and the centrifugation time is 20-40 min.

[0016] Furthermore, during the melt centrifugation process, the volume of the upper light molten component removed accounts for 75-80% of the total volume of the molten automobile dismantling residue.

[0017] Furthermore, the particle size of the upper lightweight and lower heavy molten components after cooling and crushing is 5-7 mm.

[0018] It should be noted that when mixing the obtained heavy component particles and light component particles with pulverized coal, the components can be pre-mixed evenly and then injected into the blast furnace; or the heavy component particles and light component particles can be directly mixed with pulverized coal through the blast furnace tuyeres during the blast furnace injection process.

[0019] In summary, by adopting the technical solution provided by this invention, the following beneficial effects can be achieved compared with the prior art: (1) This invention mixes zinc-containing automobile dismantling residue with titanium-containing waste catalyst, which can replace part of the pulverized coal for blast furnace injection. On the one hand, it realizes the simultaneous resource utilization of automobile dismantling residue and titanium-containing waste catalyst, which is of great significance for realizing the circular economy. On the other hand, it can also use the titanium in the titanium-containing waste catalyst to solidify the zinc in the automobile dismantling residue during the injection process. The two react to generate zinc titanate, which can avoid the damage to the blast furnace after the reduction and evaporation of titanium oxide.

[0020] (2) In this invention, the automobile dismantling residue is first melted and centrifuged. Then, titanium-containing waste catalyst is added to the separated upper light molten component. After that, the upper light component and the lower heavy component are cooled and crushed respectively before being used for blast furnace injection. This can further solve the problem of easy stratification of the upper light component and the lower heavy component during blast furnace injection. The organic matter in the automobile dismantling residue is used to solidify and bond the light fluff component, solving the problem of poor rheological properties of the light fluff component during injection. In addition, after the automobile dismantling residue is melted and centrifuged, the zinc in the automobile dismantling residue mainly deposits and accumulates in the lower heavy component, which can effectively increase its concentration in the local area, thus helping to ensure that it can fully react during injection. Detailed Implementation

[0021] The composition of automobile dismantling residue is quite complex, containing dozens of substances such as plastics, rubber, foam materials, coatings, metal particles, fiber composite materials, cloth, mud and sand, and wood chips. The specific composition is shown in Table 1 below. Among them, the plastic and other components in automobile dismantling residue are flammable. This invention uses them to replace part of the coal powder as blast furnace fuel, thereby realizing the resource recycling of automobile dismantling residue in the metallurgical process.

[0022] Table 1. Main components of existing conventional ASR (zinc accounts for 1-2% of the metal content).

[0023] However, since automobile dismantling residue contains a certain amount of zinc oxide, it is easily reduced to elemental zinc during subsequent reduction processes. Elemental zinc has a low boiling point, and after evaporation, it forms zinc vapor, which rises within the blast furnace, cools in the upper part, and accumulates on the furnace wall, forming furnace nodules. This causes corrosion and expansion of refractory materials, which is the main reason why zinc damages the blast furnace. Therefore, this invention, by adding a certain amount of titanium-containing waste catalyst, can effectively fix zinc using the titanium in the waste catalyst during blast furnace injection, allowing zinc to react with titanium to form zinc titanate. This effectively suppresses the damage caused by zinc in automobile dismantling residue to the blast furnace and enables the synergistic treatment of automobile dismantling residue and titanium-containing waste catalyst. The titanium-containing waste catalyst mentioned in this invention can be an SCR denitrification catalyst, but is not limited to it.

[0024] In one embodiment of the present invention, zinc-containing automobile dismantling residue and titanium-containing waste catalyst can be directly physically mixed after crushing or grinding, and then used for blast furnace injection. This method is relatively simple to operate. The mixing ratio of the zinc-containing automobile dismantling residue and the titanium-containing waste catalyst is determined to ensure that the zinc in the zinc-containing automobile dismantling residue can fully react, preferably a mass ratio of 1:0.3-0.7.

[0025] However, due to the complex composition of automobile dismantling residue, with significant differences in density between light and heavy components, stratification easily occurs during blast furnace injection under the influence of high-speed airflow, which is detrimental to blast furnace operation. Therefore, as a further preferred embodiment of the present invention, zinc-containing automobile dismantling residue is heated and melted, mixed with titanium-containing waste catalyst, and then cooled, granulated, and used for blast furnace injection.

[0026] As a further preferred embodiment of the present invention, the automobile dismantling residue is first preheated, melted, and centrifuged to obtain an upper light molten component and a lower heavy molten component. Then, titanium-containing waste catalyst is added to the upper light molten component for mixing. Finally, the light molten component and the heavy molten component are cooled and crushed respectively and then used together for blast furnace injection. The upper lightweight component obtained from the melting and separation of automobile dismantling residue mainly contains organic components and lightweight fluff components. The molten organic components can bind and solidify lightweight, non-meltable components such as leather and fibers, thus preventing the poor rheological properties of the lightweight fluff components during subsequent direct injection. Oxides such as ZnO, SiO2, Al2O3, and TiO2 in the automobile dismantling residue mainly accumulate in the lower heavy component. Therefore, centrifugal separation can effectively increase the concentration of these oxides in localized areas, increasing their reaction probability with zinc in the waste catalyst during blast furnace injection. This further ensures that ZnO in the automobile dismantling residue can be fully converted into high-melting-point substances, avoiding the damage of zinc to the blast furnace. Furthermore, adding the waste catalyst to the upper lightweight molten component, followed by cooling and crushing to obtain the lightweight component, can adjust the density of the upper lightweight component, further preventing stratification during blast furnace injection.

[0027] Furthermore, when using this preferred method, the amount of titanium-containing waste catalyst added is such that the density difference between the upper light component and the lower heavy component obtained after adding the waste catalyst is no greater than 0.3 g / cm³. 3 As the standard.

[0028] It should be noted that, as another embodiment of the present invention, the automobile dismantling residue can also be preheated, melted, and centrifuged to obtain an upper light molten component and a lower heavy molten component. Then, the upper light molten component and the lower heavy molten component are cooled and crushed to obtain corresponding light component particles and heavy component particles. The obtained light component particles and heavy component particles are injected into the blast furnace together with pulverized coal. Under the action of high temperature and oxidizing zone in the blast furnace tuyeres, the zinc oxide in the heavy component particles can react with other oxides, such as silicon oxide and aluminum oxide, to generate high-melting-point substances. However, on the one hand, it is not possible to effectively guarantee the sufficiency of zinc oxide reaction. On the other hand, due to the relatively large density difference between the light component and the heavy component, a certain degree of stratification will still inevitably exist in the subsequent injection process. By adding a certain amount of waste catalyst to the upper light molten component, the above problems can be effectively solved.

[0029] To further understand the content of this invention, it will now be described in detail with reference to specific embodiments.

[0030] Example 1 This embodiment provides a method for co-processing automobile dismantling residue and titanium-containing waste catalyst in blast furnace injection. The zinc-containing automobile dismantling residue and titanium-containing waste catalyst are directly physically mixed after crushing or grinding, and then used for blast furnace injection. The crushed automobile dismantling residue has a particle size of 5-7 mm, and the waste catalyst is ground to below 100 mesh. The mass ratio of the zinc-containing automobile dismantling residue to the titanium-containing waste catalyst is 1:0.3-0.7, specifically 1:0.3, 1:0.4, 1:0.5, 1:0.6, or 1:0.7, but at least sufficient zinc reaction must be ensured. In this embodiment, when zinc-containing automobile dismantling residue and titanium-containing waste catalyst are applied to blast furnace injection, they can be pre-mixed physically and then injected into the blast furnace along with pulverized coal. Alternatively, the zinc-containing automobile dismantling residue and titanium-containing waste catalyst can be directly mixed with pulverized coal through the blast furnace tuyeres. The total amount of zinc-containing automobile dismantling residue and titanium-containing waste catalyst is 20-30% of the total fuel injection volume, for example, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%. This achieves synergistic resource utilization of zinc-containing automobile dismantling residue and titanium-containing waste catalyst, while effectively solving the problem of excessively rapid combustion when using pulverized coal alone, and the problem of the zinc in automobile dismantling residue causing harm to the blast furnace when using only automobile dismantling residue. Specifically, in this embodiment, the titanium-containing waste catalyst uses an SCR denitrification catalyst, the composition of which is shown in Table 2. The total amount of zinc-containing automobile dismantling residue and titanium-containing waste catalyst is 20% of the total fuel injection amount, and the pulverized coal injection amount is 80% of the total fuel injection amount.

[0031] Table 2 Main components of the spent SCR catalyst in this embodiment

[0032] During injection, the injection velocity can be selected between 60-300 m / s according to the different blast furnace volumes (the larger the volume, the higher the injection velocity). Specifically, 60 m / s, 70 m / s, 80 m / s, 90 m / s, 100 m / s, 150 m / s, 180 m / s, 200 m / s, 220 m / s, 230 m / s, 240 m / s, 260 m / s, 280 m / s, or 300 m / s can be selected. The combustion zone temperature at the blast furnace tuyeres is 1600-2400 ℃, specifically 1600 ℃, 1700 ℃, 1800 ℃, 1900 ℃, 2000 ℃, 2100 ℃, 2200 ℃, 2300 ℃, or 2400 ℃. In this embodiment, the injection velocity is specifically 300 m / s. The velocity of the injection flow rate is m / s, and the temperature of the blast furnace tuyere combustion zone is 2000℃, but the values ​​of the injection flow rate and the temperature of the blast furnace tuyere combustion zone are not limited by the above specific values.

[0033] Example 2 This embodiment provides a method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection. The main differences between this embodiment and Embodiment 1 are as follows: the zinc-containing automobile dismantling residue is heated and melted, then mixed with the titanium-containing waste catalyst (the catalyst itself does not melt, but is incorporated into the molten automobile dismantling residue in powder form). After cooling and granulation, the mixture is then used for blast furnace injection. The particle size of the granulated particles is 5-7 mm. When using the method in Embodiment 1 for blast furnace injection, the light and heavy components in the zinc-containing automobile dismantling residue are prone to stratification, thus affecting blast furnace operation. The method in this embodiment can alleviate the above-mentioned stratification phenomenon to a certain extent and increase the probability of zinc in the automobile dismantling residue reacting to form zinc titanate.

[0034] Example 3 This embodiment provides a method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection. The main differences between this embodiment and Embodiment 2 are as follows: First, the automobile dismantling residue is preheated, melted, and centrifuged to obtain an upper light molten component and a lower heavy molten component. Then, the titanium-containing waste catalyst is added to the upper light molten component for mixing. The resulting light and heavy molten components are then cooled, crushed, and used together for blast furnace injection. Specifically, this embodiment further preferably includes the following processing steps: Step 1: Heat the crushed car dismantling residue to a molten state to obtain molten car dismantling residue. The heating temperature is 400℃. Step 2: Centrifuge the molten car dismantling residue at a speed of 4000 rpm for 20 minutes. Step 3: After centrifugation, the upper molten automotive dismantling residue is removed, and a certain amount of degraded SCR catalyst is added. The residue is then cooled and crushed to obtain light component particles. The resulting heavy molten component is then cooled and crushed to obtain heavy component particles. In this embodiment, the volume of the removed upper molten automotive dismantling residue accounts for 75% of the total volume of the molten automotive dismantling residue, and the density difference between the final light and heavy component particles is 0.3 g / cm³. 3 .

[0035] Step 4: The obtained heavy component particles, light component particles, and pulverized coal are mixed at the blast furnace tuyeres and injected into the blast furnace. Under the action of the combustion zone at the blast furnace tuyeres, the zinc oxide in the automobile dismantling residue reacts with the titanium in the waste catalyst to form zinc titanate. Simultaneously, it also reacts with other oxides (silicon oxide, aluminum oxide, titanium oxide, etc.) in the automobile dismantling residue to form high-melting-point substances. In this embodiment, the pulverized coal content is 80%, the automobile dismantling residue particles content is 20%, the blast furnace injection velocity is 300 m / s, and the blast furnace tuyeres combustion zone temperature is 2000 ℃.

[0036] Example 4 This embodiment provides a method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection. The operation steps are basically the same as in Embodiment 3, and the specific steps are as follows: Step 1: Heat the crushed car dismantling residue to a molten state to obtain molten car dismantling residue. The heating temperature is 550℃. Step 2: Centrifuge the molten car dismantling residue at a speed of 3000 rpm for 40 minutes. Step 3: After centrifugation, the upper molten automotive dismantling residue is removed, and a certain amount of SCR degraded catalyst is added to it. Then, it is cooled and crushed to obtain lightweight component particles. The removed upper molten automotive dismantling residue accounts for 80% of the total volume of the molten automotive dismantling residue.

[0037] Step 4: Add new molten automobile dismantling residue obtained in Step 1 to the remaining molten automobile dismantling residue, and repeat Step 2 and Step 3. Step 5: Repeat Step 4 three times, cooling and crushing the resulting molten heavy component to obtain heavy component particles. Adjust the density difference between the final light component particles and the heavy component particles to 0.2 g / cm³ based on the amount of waste catalyst added. 3 .

[0038] Step 6: Mix the obtained heavy component particles, light component particles and pulverized coal using the blast furnace tuyeres, and then inject the mixture into the blast furnace. In this embodiment, the pulverized coal accounts for 70%, the blast furnace injection velocity is 100 m / s, and the blast furnace tuyeres combustion zone temperature is 1600 ℃.

[0039] Example 5 This embodiment provides a method for the co-processing of automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection, specifically including: Step 1: Heat the crushed car dismantling residue to a molten state to obtain molten car dismantling residue. The heating temperature is 480℃. Step 2: Centrifuge the molten car dismantling residue at a speed of 3500 rpm for 30 minutes. Step 3: After centrifugation, the upper molten automotive dismantling residue is removed, and a certain amount of SCR degraded catalyst is added to it. Then, it is cooled and crushed to obtain lightweight component particles. The volume of the removed upper molten automotive dismantling residue accounts for 78% of the total volume of the molten automotive dismantling residue.

[0040] Step 4: Add new molten automobile dismantling residue obtained in Step 1 to the remaining molten automobile dismantling residue, and repeat Step 2 and Step 3. Step 5: Repeat Step 4 three times, cooling and crushing the resulting molten heavy component to obtain heavy component particles. Adjust the density difference between the final light component particles and the heavy component particles to 0.15 g / cm³ based on the amount of waste catalyst added. 3 .

[0041] Step 6: Mix the obtained heavy component particles, light component particles and pulverized coal using the blast furnace tuyeres, and then inject the mixture into the blast furnace. In this embodiment, the pulverized coal accounts for 75%, the blast furnace injection velocity is 60 m / s, and the blast furnace tuyeres combustion zone temperature is 2400 ℃.

[0042] In summary, this invention utilizes a compound of automobile dismantling residue and titanium-containing waste catalyst to replace a portion of pulverized coal in blast furnace injection, achieving simultaneous and efficient synergistic processing of both. The optimal effect is achieved when the automobile dismantling residue is first melted and centrifuged, and then the titanium-containing waste catalyst is added to the upper layer of lightweight molten automobile dismantling residue. Furthermore, within a certain range, as the amount of pulverized coal replaced by automobile dismantling residue and titanium-containing waste catalyst increases, it further improves the combustion efficiency of pulverized coal.

Claims

1. A method for co-processing of automobile shredder residue and spent catalyst containing titanium by blast furnace injection, characterized in that, First, the zinc-containing automobile dismantling residue is heated, melted, and centrifuged to obtain an upper light molten component and a lower heavy molten component. Then, titanium-containing waste catalyst is added to the upper light molten component for mixing. The resulting light and heavy molten components are then cooled, crushed, and used together for blast furnace injection. Under the action of the combustion zone at the blast furnace tuyeres, the zinc oxide in the automobile dismantling residue reacts with the titanium in the waste catalyst to generate zinc titanate.

2. The method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection according to claim 1, characterized in that, The titanium-containing waste catalyst is an SCR denitrification catalyst.

3. The method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection according to claim 1, characterized in that, The mass ratio of zinc-containing automobile dismantling residue to titanium-containing waste catalyst is 1:0.3-0.

7.

4. The method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection according to claim 1 or 2, characterized in that, The amount of the titanium-containing waste catalyst to be added is such that the density difference between the light component particles and the heavy component particles obtained after the addition of the titanium-containing waste catalyst is not more than 0.3 g / cm 3 To be precise.

5. The method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection according to claim 4, characterized in that, The heating and melting temperature is 400-550℃, the centrifugation speed is 3000-4000 rpm, and the centrifugation time is 20-40 min.

6. The method for co-processing automobile dismantling residue and titanium-containing waste catalyst by blast furnace injection according to claim 4, characterized in that, When performing melt centrifugation, the volume of the upper light molten component removed accounts for 75-80% of the total volume of the molten automobile dismantling residue.

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