A method for ash reduction and purification of waste tire pyrolysis carbon black

Abstract

The invention discloses a method for ash reduction and purification of waste tire pyrolysis carbon black, and belongs to the technical field of high-value utilization of waste tire pyrolysis carbon black. The method is carried out according to the following steps: waste tire pyrolysis carbon black undergoes an oxidation-reduction reaction with an ammonium persulfate solution, and filtrate A and carbon black product A are obtained by filtration; metal zinc particles are added to filtrate A, and the filtrate undergoes an oxidation-reduction reaction with hydrogen ions in the filtrate, and incompletely reacted metal zinc particles and filtrate B are obtained by filtration; filtrate B is heated and evaporated to crystallize to obtain zinc sulfate heptahydrate, and ammonia generated during the heating and evaporation process is passed into water to obtain ammonia water; under the protection of an inert gas, carbon black product A is heated, and a nitrogen gas stream is condensed to obtain sublimated sulfur and carbon black product B; carbon black product B is subjected to wet magnetic separation to obtain steel particles and a carbon black slurry product; the carbon black slurry product is subjected to nanobubble flotation to obtain a pure carbon black product. The method realizes the effective recovery of each valuable component in waste tire pyrolysis carbon black.

Description

Technical Field

[0001] The invention relates to the technical field of high-value utilization of waste tire pyrolysis carbon black, and more specifically to a method for ash reduction and purification of waste tire pyrolysis carbon black. Background Art

[0002] With the rapid development of the automobile industry in recent years, the number of cars owned has become huge, and as a result, more and more discarded tires have come along. Under the influence of factors such as the annual increase in the number of cars owned, the scrapping of cars and the replacement of car models, the annual tire scrapping rate will remain between 6% and 8%.

[0003] Compared with other waste tire treatment methods such as incineration, refurbishment, heat energy utilization, manufacturing rubber powder and recycled rubber, waste tire pyrolysis is more in line with the principles of resource utilization, harmlessness and reduction of waste treatment, and has the advantages of large processing volume, low environmental pollution and high efficiency. Therefore, as a way to complete the recycling of tire resources from the final way, pyrolysis technology has begun to be applied in some regions at home and abroad.

[0004] However, due to the addition of additives such as ZnO, Al2O3, and SiO2 during tire production, these additives are converted into ash in the carbon black product during the production of carbon black by pyrolysis of waste tires. The presence of ash in pyrolysis carbon black restricts its application scope and field, and has a certain impact on the reprocessing and utilization of pyrolysis carbon black. Therefore, ash reduction of waste tire pyrolysis carbon black is an urgent problem to be solved for its high-value utilization.

[0005] At present, there are many methods for reducing ash from waste tire pyrolysis carbon black, including physical sorting and chemical leaching. Among them, physical methods include direct flotation, graded magnetic separation and cyclone separation. Although the process of directly flotating pyrolysis carbon black is simple, easy to operate and low-cost, the ash reduction of pyrolysis carbon black by direct flotation is generally only about 2% to 4%, and the effect is poor. This is mainly because the carbon black particles are too fine (submicron level) and the surface properties are complex. Carbon black and the impurity minerals therein are interwoven, and a large amount of carbon black is coated on the surface of the impurity minerals. Traditional grinding methods are difficult to achieve the purpose of dissociation. Therefore, the direct flotation effect is not ideal, and it is necessary to dissociate before flotation. Chemical leaching uses different acid solutions to treat carbon black, including nitric acid, hydrochloric acid, sulfuric acid, glacial acetic acid, etc. However, whether it is a physical method or a chemical method, the treatment efficiency used alone is relatively low, and it is impossible to achieve the full recovery of valuable components, and it is easy to cause serious secondary pollution. Summary of the invention

[0006] In view of the above problems, the present invention discloses a method for ash reduction and purification of waste tire pyrolysis carbon black. The waste tire pyrolysis carbon black is taken as the research object, and wet oxidation leaching, high-temperature sublimation sulfur extraction, magnetic separation iron removal, nano bubble flotation carbon collection and other methods are adopted to effectively recover the valuable components in the waste tire pyrolysis carbon black. The method is a combined selection and metallurgy method with simple and efficient process, and all components are recovered without causing secondary pollution to the environment.

[0007] The purpose of this method is to provide a method for ash reduction and purification of waste tire pyrolysis carbon black, which is carried out according to the following steps:

[0008] Step 1: Under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution undergo redox reaction, and after the reaction is complete, filtrate A and carbon black product A are obtained by filtration;

[0009] Step 2, adding metal zinc particles to the filtrate A to react with the hydrogen ions in the filtrate to produce an oxidation-reduction reaction, and filtering after the reaction to obtain the incompletely reacted metal zinc particles and the filtrate B;

[0010] Step 3, heating the filtrate B for evaporation and crystallization to obtain zinc sulfate heptahydrate, and passing ammonia gas generated during the heating and evaporation process into water to obtain ammonia water;

[0011] Step 4: Under the protection of an inert gas, the carbon black product A is heated, and the nitrogen gas flow is condensed to obtain sublimated sulfur and a carbon black product B;

[0012] Step 5: performing wet magnetic separation on the carbon black product B to obtain steel particles and carbon black slurry products;

[0013] Step 6: Perform nanobubble flotation on the carbon black slurry product to remove quartz and calcite impurities to obtain a pure carbon black product.

[0014] Preferably, in step 1, the ultrasonic frequency is 30-40kHz, the leaching temperature is 30°C-40°C, and the leaching time is 60min; wherein the concentration of the ammonium persulfate solution is 0.8-1mol / L, and the ratio of waste tire pyrolysis carbon black to the ammonium persulfate solution is 300-350g / L.

[0015] Preferably, in step 2, the stirring speed is 300-450 r / min, the reaction time is 30 min, the pH is 5.5-6.5, the particle size of the metal zinc particles is 0.5-1 mm; and the concentration of the metal zinc particles in the filtrate A is 15-30 g / L.

[0016] Preferably, in step 3, the evaporation temperature is 80-100°C, then evaporated to 50°Be, cooled and crystallized at 10-15°C, and centrifuged and dried to obtain zinc sulfate heptahydrate.

[0017] Preferably, in step 4, the heating temperature is between 140-160° C., and the nitrogen flow rate is 0.5-1.5 L / min.

[0018] Preferably, in step 5, the carbon black product B is mixed with water and fully stirred and dispersed to prepare a slurry, and magnetic separation is performed; wherein the slurry concentration is 120-150 g / L, the magnetic flux of the magnetic roller is 2000 GS, and the magnetic roller speed is 80-120 r / min.

[0019] Preferably, in step 6, the concentration of the carbon black slurry product is 20-150 g / L, and then the inhibitor, collector, and frother flotation reagent are added in sequence, and the flotation aeration volume is 0.1-0.5 m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 50-1000nm.

[0020] Preferably, in step 6, the inhibitor used is one of water glass, sodium sulfide, zinc sulfate, sodium cyanide, potassium dichromate, lime, hematite, tannin, starch, dextrin, and carboxymethyl cellulose, and the added amount of the inhibitor is 1000-2000 g / t.

[0021] Preferably, in step 6, the collector used is one of kerosene and diesel, and the added amount of the collector is 500-1000 g / t.

[0022] Preferably, in step 6, the foaming agent used is one of pine oil, eucalyptus oil, octanol and fusel alcohol, and the addition amount of the foaming agent is 500-1000g / t.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention starts from the mineralogical characteristics of waste tire pyrolysis carbon black, combines wet oxidation decomposition, high temperature sublimation sulfur extraction, magnetic separation iron removal, nano bubble flotation carbon collection and other selection-metallurgy combined methods to comprehensively recover the valuable components in waste tire pyrolysis carbon black, thereby achieving the purpose of ash reduction and purification. The method has simple process flow in each link and high recovery efficiency of each component, including elemental zinc, elemental sulfur and purified carbon black, wherein elemental zinc is recovered in the form of zinc sulfate heptahydrate; elemental sulfur is recovered in the form of elemental sulfur. It will not cause secondary pollution to the environment, and all components of waste tire pyrolysis carbon black can be recovered. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the process flow of the method of the present invention;

[0026] Figure 2 The ash content and recovery rate using the method of Example 1;

[0027] Figure 3XRD comparison diagram of waste tire pyrolysis carbon black, carbon black product A, carbon black slurry product, nano bubble floating matter, and pure carbon black product in Example 1;

[0028] Figure 4 This is an XRD comparison chart of waste tire pyrolysis carbon black, conventional direct flotation floats, and conventional direct flotation sediments in Comparative Example 1. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black. Figure 1 .

[0032] The specific steps are as follows:

[0033] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 350 g / L, and the reaction material was filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 40 kHz, the leaching temperature was 35° C., the concentration of the ammonium persulfate solution was 0.85 mol / L, and the leaching time was 60 minutes;

[0034] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, removing zinc sulfide and generating elemental sulfur and zinc ions (ZnS+S2O8 2- →Zn 2+ +S↓+SO4 2- ), after filtration, a solid and a filtrate containing zinc ions are obtained, and the solid enters the next process as a carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0035] (2) Add excess metallic zinc particles (the concentration of metallic zinc particles in the filtrate A is 20 g / L) to the zinc ion-containing filtrate A obtained in step (1), wherein the zinc particles have a particle size of 0.5-1 mm and react with the hydrogen ions in the filtrate A for 30 min, (Zn+H + →Zn 2+ +H2↑) The stirring speed of the reactor is 450r / min, and the pH at the reaction end is controlled at 6.0. The product after the reaction is completed is filtered using a filtering device to obtain unreacted metal zinc particles and a filtrate B containing zinc ions.

[0036] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0037] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 160° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 1.2 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0038] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 150 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0039] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0040] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → foaming agent → aeration volume → flotation time). Specifically, the carbon black slurry in step (5) is slurried for 2-5 minutes to wet the carbon black particles with water. The carbon black slurry is poured into the flotation tank, water is added to the first mark, the flotation machine is started and stirred for 2 minutes until the carbon black is completely wetted, water is added to the second mark and stirred for 2 minutes. During the stirring process, the nanobubble generating device and the air inlet valve are turned on and the air intake volume is adjusted. Then, the inhibitor is added to the slurry below the surface and stirred for 2 minutes, then the collector is added to the surface, and the foaming agent is added to the surface after 1 minute. After stirring for 10 seconds, the nanobubble generator and the air inlet valve are turned on, and the scraper switch is turned on at the same time to start scraping bubbles. The scraping time is 7 minutes, and then the floating objects and the sinking objects are filtered, dried and analyzed later.

[0041] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the carbon black slurry concentration is 120g / L, the inhibitor is water glass, the addition amount is 1500g / t, the collector is kerosene, the addition amount is 800g / t, the foaming agent is octanol, the addition amount is 1000g / t, and the flotation aeration volume is 0.4m3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 8min.

[0042] Example 2

[0043] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0044] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 300 g / L, and the materials after the reaction were filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 30 kHz, the leaching temperature was 30° C., the concentration of ammonium persulfate solution was 0.80 mol / L, and the leaching time was 60 minutes;

[0045] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0046] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 15 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 300 r / min, and the pH at the end of the reaction is controlled at 5.5. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0047] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0048] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 140°C to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 0.5 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0049] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 120 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0050] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0051] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0052] The specific flotation operation steps are the same as those in Example 1.

[0053] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 20g / L, the inhibitor is sodium sulfide, the addition amount is 1000g / t, the collector is diesel, the addition amount is 500g / t, the foaming agent is eucalyptus oil, the addition amount is 800g / t, and the flotation aeration volume is 0.1m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 10min.

[0054] Example 3

[0055] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0056] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 320 g / L, and the materials after the reaction were filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 35 kHz, the leaching temperature was 10° C., the concentration of the ammonium persulfate solution was 1.0 mol / L, and the leaching time was 60 minutes;

[0057] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0058] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 30 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 350 r / min, and the pH at the end of the reaction is controlled at 6.5. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0059] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0060] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 150° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 1.5 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0061] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 130 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0062] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0063] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0064] The specific flotation operation steps are the same as those in Example 1.

[0065] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 150g / L, the inhibitor is zinc sulfate, the addition amount is 2000g / t, the collector is kerosene, the addition amount is 1000g / t, the frother is octanol, the addition amount is 1500g / t, and the flotation aeration volume is 0.5m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 3min.

[0066] Example 4

[0067] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0068] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 330 g / L, and the materials after the reaction were filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 40 kHz, the leaching temperature was 40° C., the concentration of the ammonium persulfate solution was 0.9 mol / L, and the leaching time was 60 minutes;

[0069] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0070] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 20 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in filtrate A for 30 min. The stirring speed of the reactor is 400 r / min, and the pH at the end of the reaction is controlled at 5.5. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0071] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0072] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 155° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 0.8 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0073] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 140 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0074] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0075] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0076] The specific flotation operation steps are the same as those in Example 1.

[0077] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 40g / L, the inhibitor is sodium cyanide, the addition amount is 1500g / t, the collector is diesel, the addition amount is 600g / t, the frother is fusel alcohol, the addition amount is 1200g / t, and the flotation aeration volume is 0.3m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 5min.

[0078] Example 5

[0079] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0080] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 310 g / L, and the reaction material was filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 30 kHz, the leaching temperature was 40° C., the concentration of the ammonium persulfate solution was 0.95 mol / L, and the leaching time was 60 minutes;

[0081] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0082] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 25 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 450 r / min, and the pH at the reaction end point is controlled at 6. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0083] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0084] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 145°C to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 1 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0085] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 150 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0086] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0087] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0088] The specific flotation operation steps are the same as those in Example 1.

[0089] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 60g / L, the inhibitor is potassium dichromate, the addition amount is 1600g / t, the collector is kerosene, the addition amount is 900g / t, the foaming agent is pine oil, the addition amount is 1000g / t, and the flotation aeration volume is 0.2m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 15min.

[0090] Example 6

[0091] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0092] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 350 g / L, and the reaction material was filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 35 kHz, the leaching temperature was 40° C., the concentration of ammonium persulfate solution was 0.85 mol / L, and the leaching time was 60 minutes;

[0093] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0094] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 20 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 450 r / min, and the pH at the reaction end point is controlled at 6. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0095] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0096] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 160° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 1.2 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0097] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 150 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0098] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0099] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0100] The specific flotation operation steps are the same as those in Example 1.

[0101] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 80g / L, the inhibitor is lime, the addition amount is 1800g / t, the collector is diesel, the addition amount is 500g / t, the foaming agent is eucalyptus oil, the addition amount is 800g / t, and the flotation aeration volume is 0.1m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 7min.

[0102] Example 7

[0103] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0104] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 300 g / L, and the materials after the reaction were filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 30 kHz, the leaching temperature was 30° C., the concentration of the ammonium persulfate solution was 0.8 mol / L, and the leaching time was 60 minutes;

[0105] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0106] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 15 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 400 r / min, and the pH at the end of the reaction is controlled at 5.5. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0107] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0108] (4) Under argon protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 140°C to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 0.5 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0109] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 130 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0110] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0111] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0112] The specific flotation operation steps are the same as those in Example 1.

[0113] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 100g / L, the inhibitor is yellow blood salt, the addition amount is 1000g / t, the collector is kerosene, the addition amount is 800g / t, the foaming agent is 2-octanol, the addition amount is 1000g / t, and the flotation aeration volume is 0.5m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 8min.

[0114] Example 8

[0115] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0116] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 330 g / L, and the materials after the reaction were filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 35 kHz, the leaching temperature was 40° C., the concentration of the ammonium persulfate solution was 1 mol / L, and the leaching time was 60 minutes;

[0117] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0118] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 30 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 350 r / min, and the pH at the end of the reaction is controlled at 6.5. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0119] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0120] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 150° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 0.9 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0121] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 140 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 80 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0122] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0123] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0124] The specific flotation operation steps are the same as those in Example 1.

[0125] The nanobubbles in this step are generated by the Venturi jet method. During the sorting process, the pulp concentration is 120g / L, the inhibitor is tannin, the addition amount is 1000g / t, the collector is kerosene, the addition amount is 800g / t, the foaming agent is octanol, the addition amount is 1000g / t, and the flotation aeration volume is 0.4m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 15min.

[0126] Example 9

[0127] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0128] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 310 g / L, and the reaction material was filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 30 kHz, the leaching temperature was 40° C., the concentration of the ammonium persulfate solution was 0.9 mol / L, and the leaching time was 60 minutes;

[0129] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0130] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 20 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 450 r / min, and the pH at the reaction end point is controlled at 6. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0131] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 90°C, then evaporated to 50°Be, cooled and crystallized at 15°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0132] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 155° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 0.8 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0133] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 150 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the speed of the magnetic roller is 100 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0134] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0135] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0136] The specific flotation operation steps are the same as those in Example 1.

[0137] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 70g / L, the inhibitor is starch, the addition amount is 1000g / t, the collector is diesel, the addition amount is 800g / t, the frother is fusel alcohol, the addition amount is 1000g / t, and the flotation aeration volume is 0.2m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 10min.

[0138] Example 10

[0139] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0140] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 350 g / L, and the reaction material was filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 40 kHz, the leaching temperature was 35° C., the concentration of the ammonium persulfate solution was 0.85 mol / L, and the leaching time was 60 minutes;

[0141] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0142] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 30 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 450 r / min, and the pH at the reaction end point is controlled at 6. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0143] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 100°C, then evaporated to 50°Be, cooled and crystallized at 13°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia into the water to obtain ammonia water.

[0144] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 160° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 1 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0145] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 140 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 100 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0146] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0147] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0148] The specific flotation operation steps are the same as those in Example 1.

[0149] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 120g / L, the inhibitor is dextrin, the addition amount is 1000g / t, the collector is kerosene, the addition amount is 800g / t, the foaming agent is pine oil, the addition amount is 1000g / t, and the flotation aeration volume is 0.4m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 12min.

[0150] Embodiment 11

[0151] This embodiment provides a method for ash reduction and purification of waste tire pyrolysis carbon black, and the specific steps are as follows:

[0152] (1) under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution were added to react at a solid-liquid ratio of 350 g / L, and the materials after the reaction were filtered to obtain filtrate A and carbon black product A. During the leaching process, the ultrasonic frequency was 40 kHz, the leaching temperature was 40° C., the concentration of the ammonium persulfate solution was 0.9 mol / L, and the leaching time was 60 minutes;

[0153] In this process, ammonium persulfate reacts with zinc sulfide in carbon black, and while removing zinc sulfide, elemental sulfur and zinc ions are generated. After filtration, solid and zinc ion-containing filtrate are obtained. The solid enters the next process as carbon black product A. In this step, the zinc sulfide removal rate is higher than 98%.

[0154] (2) Add excess metal zinc particles (the concentration of metal zinc particles in filtrate A is 20 g / L) to the zinc ion-containing filtrate A obtained in step (1), the zinc particles have a particle size of 0.5-1 mm, and react with the hydrogen ions in the filtrate A for 30 min. The stirring speed of the reactor is 450 r / min, and the pH at the end of the reaction is controlled at 5.5. The product after the reaction is filtered using a filtering device to obtain unreacted metal zinc particles and zinc ion-containing filtrate B.

[0155] (3) The filtrate B obtained by filtration is heated and evaporated, the temperature is controlled at 80°C, then evaporated to 50°Be, cooled and crystallized at 10°C, dehydrated using a centrifuge, and the solid product of the centrifuge is dried using a drying device to obtain a zinc sulfate heptahydrate product. During the heating and evaporation stage, the unreacted ammonium persulfate in the solution will decompose to produce ammonia gas. In order to avoid air pollution, an air pump and a draft device are used to pass the ammonia gas into the water to obtain ammonia water.

[0156] (4) Under nitrogen protection, the carbon black product A is heated in a tubular furnace with a diameter of 0.15 m and the temperature is maintained at 160° C. to sublime the sulfur attached to the surface of the carbon black particles. The nitrogen flow rate is 1.5 L / min. The nitrogen flow is quickly condensed at the outlet of the tubular furnace to collect the sulfur element. The carbon black product B remains in the tubular furnace. In this process, the sulfur recovery rate is higher than 95%.

[0157] (5) After the carbon black product B is mixed with water and fully stirred and dispersed, a wet magnetic separator is used for magnetic separation, the slurry concentration is 150 g / L, the magnetic flux of the magnetic roller of the magnetic separator is 2000 GS, and the rotation speed of the magnetic roller is 120 r / min, to obtain steel particles and carbon black slurry products. In this process, the steel particle removal rate is higher than 98%.

[0158] (6) The carbon black slurry product is subjected to nanobubble flotation to remove impurities such as quartz and calcite to obtain a pure carbon black product.

[0159] The carbon black slurry obtained in step (5) is subjected to nanobubble flotation, and the nanobubble flotation of the cracked carbon black is carried out in accordance with the conventional flotation operation sequence (slurry concentration → inhibitor → collector → frother → aeration volume → flotation time).

[0160] The specific flotation operation steps are the same as those in Example 1.

[0161] In this step, nanobubbles are generated by the Venturi jet method. During the sorting process, the pulp concentration is 120g / L, the inhibitor is hydroxymethyl cellulose, the addition amount is 2000g / t, the collector is kerosene, the addition amount is 800g / t, the foaming agent is pine oil, the addition amount is 1000g / t, and the flotation aeration volume is 0.4m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 20-1000nm, and the flotation time is 9min.

[0162] The waste tire pyrolysis carbon black ash reduction and purification method of Example 1 is used to Figure 2 It can be seen that when using nanobubble flotation, the best recovery rate of cracked carbon black is 90.04% and the ash content is 3.38% when the flotation time is 5 minutes. Compared with the raw material, the ash content is reduced from about 19% to 3.38%, and the ash reduction effect is obvious, indicating that nanobubbles not only have a higher recovery rate of carbon black floating matter, but also can significantly reduce the ash content of carbon black.

[0163] Comparative Example 1

[0164] Direct flotation method was used to flotate waste tire pyrolysis carbon black. The amount of collector kerosene was 500 g / t, the amount of frother octanol was 1500 g / t, and the amount of aeration was 0.25 m 3 / h, slurry concentration of 20g / L, scraping time of 9min, the floating ash content was 17.29% and the yield was 62.32%.

[0165] From the XRD qualitative analysis results, it can be seen that the impurities in waste tire pyrolysis carbon black are mainly calcite, zinc sulfide and silica. Figure 3 In this table, the original ore refers to the carbon black from the cracking of waste tires, the carbon black product A after leaching (containing sulfur), the flotation feed (desulfurization) refers to the carbon black slurry product, the floating matter refers to the nano bubble floating matter, and the sinker refers to the pure carbon black product. Figure 3 It can be seen that the characteristic peak of elemental sulfur appears in the carbon black product A, indicating that elemental sulfur is generated. The carbon black slurry product obtained after desulfurization and magnetic separation is used as the feed for nanobubble flotation. The XRD image of the nanobubble float shows that the nanobubble float contains almost no silicon dioxide, but the silicon dioxide content in the nanobubble sediment increases sharply. This shows that nanobubbles have a good purification effect on thermal cracking carbon black. Figure 4 In this paper, the input material refers to the carbon black from waste tire pyrolysis, the floating matter refers to the floating matter from conventional direct flotation, and the sinker refers to the sinker from conventional direct flotation. Figure 4 It can be seen that after the direct flotation of the thermal cracking carbon black ore by conventional bubbles, although there is a large amount of silicon dioxide enriched in the sediment, the ash content of the float from the direct flotation does not decrease much (from about 19% to 17%), and the content of silicon dioxide and zinc sulfide in the float has hardly decreased. This is mainly due to the fact that the carbon black and these impurity minerals are not dissociated, and the thermal cracking carbon black particles are too fine. Figure 3 and Figure 4 From the comparison, it can be seen that compared with conventional direct flotation, nanobubble flotation can significantly reduce the ash content of thermal cracked carbon black after ammonium persulfate leaching.

[0166] It should be noted that the nanobubbles used in the present invention are generated by the Venturi jet method, and may also be generated by one of the ultrasonic method, pressure increase and decompression method, hydraulic cavitation method, mechanical shearing method, electrolysis method, Venturi method, etc.

[0167] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0168] 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 ash reduction and purification of waste tire pyrolysis carbon black, characterized in that: Follow these steps: Step 1, under ultrasonic conditions, waste tire pyrolysis carbon black and ammonium persulfate solution undergo redox reaction, and after the reaction is completed, filtrate A and carbon black product A are obtained by filtration; the ultrasonic frequency is 30-40kHz, the leaching temperature is 30°C-40°C, and the leaching time is 60min; wherein the concentration of the ammonium persulfate solution is 0.8-1mol / L, and the ratio of waste tire pyrolysis carbon black to the ammonium persulfate solution is 300-350g / L; Step 2, adding metal zinc particles to the filtrate A to react with the hydrogen ions in the filtrate to produce an oxidation-reduction reaction, and filtering after the reaction to obtain the incompletely reacted metal zinc particles and the filtrate B; Step 3, heating the filtrate B for evaporation and crystallization to obtain zinc sulfate heptahydrate, and passing ammonia gas generated during the heating and evaporation process into water to obtain ammonia water; Step 4: Under the protection of an inert gas, the carbon black product A is heated and the nitrogen flow is condensed to obtain sublimated sulfur and the carbon black product B; the heating temperature is between 140-160° C. and the nitrogen flow rate is 0.5-1.5 L / min; Step 5, wet magnetic separation of the carbon black product B to obtain steel particles and carbon black slurry products; the carbon black product B is mixed with water and fully stirred and dispersed to prepare a slurry, and magnetic separation is performed; wherein the slurry concentration is 120-150 g / L, the magnetic flux of the magnetic roller is 2000 GS, and the rotation speed of the magnetic roller is 80-120 r / min; Step 6: Perform nanobubble flotation on the carbon black slurry product to remove quartz and calcite impurities to obtain a pure carbon black product; the concentration of the carbon black slurry product is 20-150g / L, and then an inhibitor, a collector, and a frother flotation agent are added in sequence, and the flotation aeration volume is 0.1-0.5m 3 / h, the radius of the nanobubbles produced by the nanobubble generator is 50-1000nm.

2. The method for ash reduction and purification of waste tire pyrolysis carbon black according to claim 1, characterized in that: In step 2, the stirring speed is 300-450 r / min, the reaction time is 30 min, the pH is 5.5-6.5, the particle size of the metal zinc particles is 0.5-1 mm; and the concentration of the metal zinc particles in the filtrate A is 15-30 g / L.

3. The method for ash reduction and purification of waste tire pyrolysis carbon black according to claim 1, characterized in that: In step 3, the evaporation temperature is 80-100°C, then evaporated to 50°Be, cooled and crystallized at 10-15°C, and zinc sulfate heptahydrate is obtained after centrifugal dehydration and drying.

4. The method for ash reduction and purification of waste tire pyrolysis carbon black according to claim 1, characterized in that: In step 6, the inhibitor used is one of water glass, sodium sulfide, zinc sulfate, sodium cyanide, potassium dichromate, lime, hematite, tannin, starch, dextrin, and carboxymethyl cellulose, and the addition amount of the inhibitor is 1000-2000g / t.

5. The method for ash reduction and purification of waste tire pyrolysis carbon black according to claim 1, characterized in that: In step 6, the collector used is one of kerosene and diesel, and the addition amount of the collector is 500-1000g / t.

6. The method for ash reduction and purification of waste tire pyrolysis carbon black according to claim 1, characterized in that: In step 6, the foaming agent used is one of pine oil, eucalyptus oil, octanol and fusel alcohol, and the addition amount of the foaming agent is 500-1000g / t.

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