Method for treating heavy metal-containing silicon-aluminum-based waste slag and amorphous silicon-aluminum powder and use thereof

Abstract

The present application discloses a method for treating heavy metal silicon-aluminum-based waste slag and amorphous silicon-aluminum powder and its use, and relates to the technical field of industrial solid waste treatment. The method comprises crushing the heavy metal silicon-aluminum-based waste slag and then performing alkaline dissolution treatment. The present application solves the problem that the existing method cannot achieve effective resource recovery and secondary utilization of solid waste in the heavy metal silicon-aluminum-based waste slag, reduces the treatment cost, and realizes the circular utilization of resources.

Description

Technical Field

[0001] The present application relates to the technical field of industrial solid waste treatment, and in particular to a method for treating heavy metal-containing silicon-aluminum-based waste slag, amorphous silicon-aluminum powder and uses thereof. Background Art

[0002] With the rapid development of modern industry, the discharge of waste residue is also increasing day by day. Waste residue not only occupies a large amount of land, but also causes great harm to the environment. In particular, industrial waste residue containing heavy metals pollutes the environment more and directly harms human health. Making full use of industrial waste residue can not only save energy resources and turn waste into treasure, but also improve the environment and reduce the huge economic losses caused by secondary pollution. At present, there are two main methods for treating hazardous waste containing heavy metals: one is to directly reuse it after stabilization, such as CN105618468A and CN108411113A. This method cannot recover heavy metal elements, resulting in waste of resources, and usually requires high-temperature smelting, which consumes a lot of energy, has low product added value and unsatisfactory economic benefits; the other is wet acid hydrolysis-metal recovery method. Due to the limitation of the reactant structure, a super-acid environment is usually required to ensure a high leaching rate of heavy metals, which brings certain difficulties to the subsequent heavy metal recovery. In addition, this type of hazardous waste usually contains more alkali metals. In the process of acid leaching to recover heavy metals, a large amount of alkali metals will be precipitated and mixed into metal salts or metal hydroxides, making them difficult to separate.

[0003] Silica-alumina-based waste slag containing heavy metals is a type of non-porous silica-alumina-based hazardous waste containing heavy metals. It has the characteristics of high carbon content, low specific surface area, high calcium and magnesium content, irregular surface morphology, and high heavy metal nickel and vanadium content. Because it has no internal pore structure and some heavy metals are wrapped in the silica-alumina structure, it is difficult to obtain a high reaction specific surface area by mechanical crushing alone. If the above method is used to treat hazardous wastes with complex composition and properties such as silica-alumina-based waste slag containing heavy metals, it is impossible to effectively recover heavy metals and achieve secondary utilization of silica-alumina-based waste slag containing heavy metals. Therefore, for hazardous wastes such as silica-alumina-based waste slag containing heavy metals, a new disposal method needs to be developed to achieve resource recycling. Summary of the invention

[0004] The embodiments of the present application provide a method for treating heavy metal silicon-aluminum-based waste slag, amorphous silicon-aluminum powder and uses thereof, thereby solving the problem that existing methods are unable to achieve effective resource recovery and secondary utilization of solid waste in heavy metal silicon-aluminum-based waste slag, reducing processing costs and achieving circular utilization of resources.

[0005] To achieve the above objectives, the embodiments of the present application mainly provide the following technical solutions:

[0006] The embodiment of the present application provides a method for treating silicon-aluminum-based waste slag containing heavy metals, the method comprising crushing the silicon-aluminum-based waste slag containing heavy metals and then performing alkaline dissolution treatment.

[0007] Preferably, the specific surface area of ​​the heavy metal-containing silicon-aluminum-based waste slag is not higher than 10m 2 / g; the heavy metal-containing silicon-aluminum-based waste slag contains at least one of the heavy metal elements nickel, iron and vanadium.

[0008] Preferably, the heavy metal-containing silicon-aluminum-based waste slag is petroleum coke gasification ash.

[0009] Preferably, the heavy metal-containing silicon-aluminum-based waste slag is crushed to a particle size of less than 90 μm.

[0010] Preferably, the alkaline solution used in the alkaline dissolution treatment is an inorganic alkaline solution or a quaternary ammonium alkaline solution or a mixed solution of the two.

[0011] Preferably, the inorganic base is one or more of sodium hydroxide, potassium hydroxide and ammonium hydroxide; and the quaternary ammonium base is tetramethylammonium hydroxide.

[0012] Preferably, the mass concentration of the alkaline solution used in the alkaline dissolution treatment is 3%-5%.

[0013] Preferably, the reaction temperature of the alkali dissolution treatment is 100-180°C, and the reaction time is 2-3h.

[0014] Preferably, when the heavy metal-containing silicon-aluminum-based waste slag contains heavy metal vanadium, the method further comprises: filtering the heavy metal-containing silicon-aluminum-based waste slag after alkali dissolution, adding calcium salt to the filtrate, filtering after the reaction is completed, and obtaining calcium vanadate slag.

[0015] Preferably, the method further comprises: filtering the heavy metal-containing silicon-aluminum-based waste residue after alkali dissolution, and performing a chlorination reaction on the obtained filter residue after washing and drying.

[0016] Preferably, the temperature of the chlorination reaction is 500-650°C.

[0017] Preferably, the method further comprises: obtaining chlorinated flue gas and chlorinated slag through a chlorination reaction, condensing and recovering the chlorinated flue gas to obtain one or more of iron chloride, aluminum chloride and vanadium chloride, filtering the chlorinated slag after washing to obtain metal chloride filtrate and tailings; and roasting the tailings to obtain amorphous silicon aluminum powder.

[0018] Preferably, when the chlorinated flue gas is condensed and recovered, a portion of the chlorinated flue gas is collected after settling by gravity, and the remaining chlorinated flue gas is condensed at 80-100°C to obtain at least one of the crude products of FeCl3 and AlCl3 and the condensed flue gas; when the heavy metal silicon-aluminum-based waste slag contains heavy metal vanadium, the condensed flue gas is condensed at -20-0°C to obtain the crude VOCl3 product.

[0019] Preferably, when the heavy metal-containing silicon-aluminum-based waste slag contains heavy metal nickel, the method further comprises: adding alkali to the metal chloride filtrate, and after the reaction is completed, filtering to obtain a crude nickel hydroxide product and saline wastewater.

[0020] The embodiment of the present application also provides an amorphous silicon-aluminum powder, which is prepared from silicon-aluminum-based waste slag containing heavy metals according to the above method.

[0021] The embodiments of the present application also provide the use of the amorphous silicon aluminum powder as a raw material for building materials.

[0022] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0023] The embodiment of the present application performs an alkaline dissolution treatment on the silicon-aluminum-based waste slag containing heavy metals before the chlorination treatment. First, the stable structure of the silicon-aluminum-based waste slag can be destroyed, the specific surface area of ​​the silicon-aluminum-based waste slag can be increased, the efficiency of the subsequent chlorination reaction can be improved, and the effective recovery of resources can be achieved; secondly, when the same treatment effect is achieved, the crushing degree of the silicon-aluminum-based waste slag can be increased from 10μm to 90μm, which greatly reduces the cost of crushing treatment; finally, the shape of the microscopic particles of the silicon-aluminum-based waste slag can be improved, the fluidity of the silicon-aluminum-based waste slag can be improved, and the silicon-aluminum-based waste slag can be made more conducive to the operation of the subsequent fluidized bed chlorination reactor. The treatment method provided in the embodiment of the present application not only has a high resource recovery rate in the silicon-aluminum-based waste slag containing heavy metals, can realize the secondary utilization of solid waste, but also has a low treatment cost and is suitable for large-scale industrial treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a chlorination treatment route for heavy metal-containing silicon-aluminum-based waste slag in the examples of this application;

[0025] Figure 2 This is a surface morphology diagram of the petroleum coke gasification ash in the embodiment of the present application before alkali dissolution treatment;

[0026] Figure 3 This is the apparent morphology of the petroleum coke gasification ash after alkali dissolution treatment in the examples of the present application. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present application scheme by those skilled in the art, the present application scheme is further elaborated below in conjunction with specific embodiments. It should be understood that the embodiments of the present application are explanations of the present application scheme and are not intended to limit the scope of protection of the present application.

[0028] The embodiments of the present application provide a method for treating heavy metal silicon-aluminum-based waste slag, amorphous silicon-aluminum powder and uses thereof, thereby solving the problem that existing methods are unable to achieve effective resource recovery and secondary utilization of solid waste in heavy metal silicon-aluminum-based waste slag, reducing processing costs and achieving circular utilization of resources.

[0029] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows:

[0030] The present application provides a method for treating heavy metal-containing silicon-aluminum-based waste slag, such as Figure 1 As shown, the method includes crushing the heavy metal silicon-aluminum-based waste slag and then performing alkali dissolution treatment.

[0031] The heavy metal-containing silicon-aluminum-based waste slag in the embodiments of the present application is a type of non-porous silicon-aluminum-based hazardous waste containing heavy metals, which has the characteristics of high carbon content, low specific surface area, high calcium and magnesium content, irregular surface morphology, high heavy metal nickel and vanadium content, etc. It has no internal pore structure, and some heavy metals are wrapped in the silicon-aluminum structure.

[0032] In the embodiment of the present application, the specific surface area of ​​the heavy metal-containing silicon-aluminum-based waste slag is not higher than 10m 2 / g; preferably, the heavy metal-containing silicon-aluminum-based waste slag contains at least one of the heavy metal elements nickel, iron and vanadium, and at least one of the elements sodium, potassium, magnesium and calcium.

[0033] In a preferred embodiment of the present application, the above-mentioned heavy metal-containing silicon-aluminum-based waste slag is petroleum coke gasification ash.

[0034] The embodiment of the present application performs alkaline dissolution treatment on the silicon-aluminum-based waste slag containing heavy metals after crushing. Firstly, the stable structure of the silicon-aluminum-based waste slag can be destroyed, the specific surface area of ​​the silicon-aluminum-based waste slag can be increased, the efficiency of the subsequent chlorination reaction can be improved, and the effective recovery of resources can be realized; secondly, when achieving the same treatment effect, the crushing degree of the silicon-aluminum-based waste slag can be increased from less than 10μm to 90μm, which greatly reduces the cost of crushing treatment; finally, the shape of the microscopic particles of the silicon-aluminum-based waste slag can be improved, and the fluidity of the silicon-aluminum-based waste slag can be improved, so that the silicon-aluminum-based waste slag is more conducive to the operation of the subsequent fluidized bed chlorination reactor.

[0035] In a preferred embodiment of the present application, the heavy metal silicon-aluminum-based waste slag is crushed to a particle size of less than 90 μm, such as a particle size of 70-90 μm, 50-70 μm, 50-90 μm, 30-50 μm, 10-30 μm, etc., and a more preferred particle size of 70-90 μm. Since the alkali dissolution treatment is first performed on the heavy metal silicon-aluminum-based waste slag before the subsequent chlorination treatment, the stable structure of the ash is destroyed and the specific surface area of ​​the ash is increased. The chlorination efficiency when the ash particle size is 90 μm can reach the chlorination efficiency when the ash particle size is less than 10 μm when the alkali dissolution treatment is not performed. Since the investment and energy consumption of crushing the ash to less than 10 μm in industry are far greater than that of 90 μm, increasing the crushing degree of the ash from less than 10 μm to 90 μm greatly reduces the production cost. Crushing the heavy metal silicon-aluminum-based waste slag to a particle size of 90 μm can not only ensure the efficiency of the chlorination reaction, but also significantly reduce the production cost and energy consumption caused by industrial ash crushing.

[0036] In a preferred embodiment of the present application, the alkaline solution used for alkaline dissolution treatment of the waste residue is a solution of an inorganic alkali or a quaternary ammonium alkali, including but not limited to an aqueous solution of sodium hydroxide, potassium hydroxide, ammonium hydroxide or tetramethylammonium hydroxide.

[0037] In a preferred embodiment of the present application, the mass concentration of the alkaline solution used in the alkaline dissolution treatment is 3%-5%, and the mass ratio of the waste residue to the alkaline solution is 1:3-1:10, preferably 1:5.

[0038] In the implementation scheme of the present application, the above-mentioned alkaline dissolution conditions adopted can ensure that the solid specific surface area is increased when the dissolution rate of vanadium is low, the apparent structure of the particles is improved, and the conversion efficiency and fluidization performance of the subsequent process are improved. The present application embodiment adopts an alkaline solution with a mass concentration of 3%-5% for alkaline dissolution, which can not only ensure the effect of alkaline dissolution of silicon-aluminum-based waste slag containing heavy metals, but also reduce the amount of alkali. Because the ash slag is not roasted before the alkaline dissolution treatment, part of the vanadium is in a low-valent state or is wrapped by carbon. The conversion rate of vanadium during alkaline dissolution is low, which can make the vanadium be concentrated and separated in the subsequent chlorination treatment process, thereby improving the separation efficiency.

[0039] In a preferred embodiment of the present application, the reaction temperature of the alkali dissolution treatment is 100-180° C., and the reaction time is 2-3 h.

[0040] In a further embodiment of the present application, when the heavy metal silicon-aluminum-based waste slag contains heavy metal vanadium, the heavy metal silicon-aluminum-based waste slag is treated with alkali and then filtered, and calcium salt is added to the filtrate. After the reaction is completed, the filtrate is filtered to obtain calcium vanadate slag. Through this step, a portion of the vanadium in the heavy metal silicon-aluminum-based waste slag is separated and recovered.

[0041] After the heavy metal silicon-aluminum-based waste residue is treated with alkali, it is filtered, and the obtained filter residue is washed and dried before chlorination reaction; wherein the chlorination reaction generally adopts an ebullating bed chlorination reactor, and a chlorine / inert gas mixture is used as a chlorinating agent. In the embodiment of the present application, the preferred chlorination reaction temperature is 500-650°C, and the chlorination reaction time is 10min-5h.

[0042] In a further embodiment of the present application, the treatment process of the above-mentioned chlorination reaction includes: obtaining chlorinated flue gas and chlorinated slag through chlorination reaction, condensing and recovering the chlorinated flue gas to obtain one or more of iron chloride, aluminum chloride and vanadium chloride, washing and filtering the chlorinated slag to obtain metal chloride filtrate and tailings; roasting the tailings to obtain amorphous silicon aluminum powder.

[0043] In the embodiment of the present application, when the chlorination method is used to dispose of the silicon-aluminum-based waste slag containing heavy metals, there is no need to carry out conventional carbon burning treatment. The carbon contained in the silicon-aluminum-based waste slag containing heavy metals can play a catalytic role in the subsequent chlorination process and promote the chlorination reaction. Therefore, there is no need to add an additional carbon source in the chlorination reaction stage. This simplifies the resource recovery and treatment steps of the silicon-aluminum-based waste slag containing heavy metals, and saves the carbon resources required for the chlorination reaction.

[0044] Specifically, when the chlorinated flue gas obtained by the chlorination reaction is condensed and recovered, a part of the chlorinated flue gas is collected after settling by gravity, and the remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. After the crude VOCl3 is refined, refined VOCl3 and a small amount of bottom slag 2 are obtained. The residual chlorine in the tail gas is absorbed by alkali solution and then emptied. Bottom slag 1 and bottom slag 2 are added to the alkali-dissolved ash to be chlorinated, and the chlorination reaction is circulated. Through this step, the separation and recovery of aluminum, iron and vanadium in the silicon-aluminum-based waste slag containing heavy metals is achieved.

[0045] Specifically, the chlorinated slag obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings, wherein the metal chloride filtrate contains Ni 2+ , Ca 2+ 、Na + , K + By adding an alkaline solution to the metal chloride filtrate to generate a precipitate, the crude nickel hydroxide and saline wastewater are obtained by filtration. The saline wastewater contains Ca 2+ 、Na + , K +The plasma can be discharged after neutralization or reused according to actual needs. The alkaline solution added to the metal chloride filtrate can be a solution of an inorganic alkali or a quaternary ammonium alkali, including but not limited to an aqueous solution of sodium hydroxide, potassium hydroxide, ammonium hydroxide or tetramethylammonium hydroxide, and the mass concentration of the alkaline solution can be 0.5%-5%.

[0046] In the implementation scheme of the present application, through the chlorination treatment step of the filter residue after alkali dissolution, the valuable resources such as iron, aluminum, vanadium, nickel, calcium, sodium, potassium, silicon and aluminum in the heavy metal silicon-aluminum-based waste slag are recovered and reused, thereby improving the comprehensive resource utilization rate of the heavy metal silicon-aluminum-based waste slag.

[0047] The embodiment of the present application also provides an amorphous silicon-aluminum powder, which is prepared from heavy metal silicon-aluminum-based waste slag according to the above method. The main components of the amorphous silicon-aluminum powder are amorphous silicon oxide and aluminum oxide, which can be used as a binder or raw material for the production of catalysts, molecular sieves, adsorbents, etc., can also be directly used for adsorption and decolorization, and can also be hot-melted for the production of silicon-aluminum fibers, and used to manufacture refractory and thermal insulation materials.

[0048] The embodiments of the present application also provide the use of the amorphous silicon aluminum powder as a raw material for building materials.

[0049] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods, but it does not serve as a limitation to the present application.

[0050] The following examples are based on Figure 1 The chlorination treatment route for heavy metal-containing silicon-aluminum-based waste slag is shown in the treatment of petroleum coke gasification ash samples.

[0051] Example 1

[0052] (1) 100 g of petroleum coke gasification ash sample was ball-milled to a particle size of 70-90 μm, added to 500 g of a 3% sodium hydroxide solution, reacted at 145° C. for 2 h, and filtered after the reaction to obtain an alkali-dissolved filtrate and an alkali-dissolved filter residue;

[0053] (2) adding an excess of CaCl2 to the filtrate after the alkali dissolution, filtering after the reaction is completed, and obtaining calcium vanadate slag;

[0054] (3) After the alkali-dissolved filter residue is washed with water and dried, it is loaded into a fluidized bed chlorination reactor, He gas is introduced into the chlorination reactor for purging, the temperature is raised to 500° C., and a chlorine / He gas mixture is introduced for chlorination reaction, and the reaction time is 30 min;

[0055] (4) After the chlorination reaction is completed, the chlorinated flue gas is condensed and recovered, specifically: a part of the chlorinated flue gas is settled by gravity and the dust is collected, and the remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. The crude VOCl3 is refined to obtain refined VOCl3 and a small amount of bottom slag 2. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged. Bottom slag 1 and bottom slag 2 are added to the alkali-dissolved ash to be chlorinated, and the chlorination reaction is circulated.

[0056] (5) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a 2% potassium hydroxide solution is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0057] Example 2

[0058] (1) 100 g of petroleum coke gasification ash sample was ball-milled to a particle size of 70-90 μm, added to 300 g of 4% ammonium hydroxide solution, reacted at 100° C. for 3 h, and filtered after the reaction to obtain an alkali-dissolved filtrate and an alkali-dissolved filter residue;

[0059] (2) adding an excess of CaCl2 to the filtrate after the alkali dissolution, filtering after the reaction is completed, and obtaining calcium vanadate slag;

[0060] (3) After the alkali-dissolved filter residue is washed and dried, it is loaded into a fluidized bed chlorination reactor, He gas is introduced into the chlorination reactor for purging, the temperature is raised to 600° C., and a chlorine / He gas mixture is introduced for chlorination reaction, and the reaction time is 30 min;

[0061] (4) After the chlorination reaction is completed, the chlorinated flue gas is condensed and recovered, specifically: a part of the chlorinated flue gas is settled by gravity and the dust is collected, and the remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. The crude VOCl3 is refined to obtain refined VOCl3 and a small amount of bottom slag 2. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged. Bottom slag 1 and bottom slag 2 are added to the alkali-dissolved ash to be chlorinated, and the chlorination reaction is circulated.

[0062] (5) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a 2% potassium hydroxide solution is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0063] Example 3

[0064] (1) 100 g of petroleum coke gasification ash sample was ball-milled to a particle size of 70-90 μm, added to 1000 g of a 5% tetramethylammonium hydroxide solution, reacted at 180° C. for 3 h, and filtered after the reaction to obtain an alkali-dissolved filtrate and an alkali-dissolved filter residue;

[0065] (2) adding an excess of CaCl2 to the filtrate after the alkali dissolution, filtering after the reaction is completed, and obtaining calcium vanadate slag;

[0066] (3) After the alkali-dissolved filter residue is washed and dried, it is loaded into a fluidized bed chlorination reactor, He gas is introduced into the chlorination reactor for purging, the temperature is raised to 650° C., and a chlorine / He gas mixture is introduced for chlorination reaction, and the reaction time is 30 min;

[0067] (4) After the chlorination reaction is completed, the chlorinated flue gas is condensed and recovered, specifically: a part of the chlorinated flue gas is settled by gravity and the dust is collected, and the remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. The crude VOCl3 is refined to obtain refined VOCl3 and a small amount of bottom slag 2. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged. Bottom slag 1 and bottom slag 2 are added to the alkali-dissolved ash to be chlorinated, and the chlorination reaction is circulated.

[0068] (5) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of 5% ammonium hydroxide solution is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0069] Comparative Example 1

[0070] This comparative example uses the same petroleum coke gasification ash sample as in Example 1.

[0071] (1) 100 g of petroleum coke gasification ash sample was ball-milled and sieved, and a sample with a particle size range of 1-10 μm and an average particle size of 2.154 μm was selected and loaded into a fluidized bed chlorination reactor. After He gas was introduced into the chlorination reactor for purging, the temperature was raised to 600° C., and a chlorine / He gas mixture was introduced for chlorination reaction, and the reaction time was 30 min;

[0072] (2) After the reaction is completed, the chlorinated flue gas is condensed and recovered. Specifically, a part of the chlorinated flue gas is settled by gravity and the dust is collected. The remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. After the crude VOCl3 is refined, refined VOCl3 and a small amount of bottom slag 2 are obtained. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged.

[0073] (3) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a sodium hydroxide solution with a mass concentration of 0.5% is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0074] Comparative Example 2

[0075] This comparative example uses the same petroleum coke gasification ash sample as in Example 1.

[0076] (1) 100 g of petroleum coke gasification ash sample was ball-milled and sieved, and a sample with a particle size range of 20-40 μm and an average particle size of 38.313 μm was selected and loaded into a fluidized bed chlorination reactor. After He gas was introduced into the chlorination reactor for purging, the temperature was raised to 600° C., and a chlorine / He gas mixture was introduced for chlorination reaction, and the reaction time was 30 min;

[0077] (2) After the reaction is completed, the chlorinated flue gas is condensed and recovered. Specifically, a part of the chlorinated flue gas is settled by gravity and the dust is collected. The remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. After the crude VOCl3 is refined, refined VOCl3 and a small amount of bottom slag 2 are obtained. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged.

[0078] (3) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a sodium hydroxide solution with a mass concentration of 0.5% is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0079] Comparative Example 3

[0080] This comparative example uses the same petroleum coke gasification ash sample as in Example 1.

[0081] (1) 100 g of petroleum coke gasification ash sample was ball-milled and sieved, and a sample with a particle size range of 40-50 μm and an average particle size of 43.588 μm was selected and loaded into a fluidized bed chlorination reactor. After He gas was introduced into the chlorination reactor for purging, the temperature was raised to 600° C., and a chlorine / He gas mixture was introduced for chlorination reaction, and the reaction time was 30 min;

[0082] (2) After the reaction is completed, the chlorinated flue gas is condensed and recovered. Specifically, a part of the chlorinated flue gas is settled by gravity and the dust is collected. The remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. After the crude VOCl3 is refined, refined VOCl3 and a small amount of bottom slag 2 are obtained. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged.

[0083] (3) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a sodium hydroxide solution with a mass concentration of 0.5% is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0084] Comparative Example 4

[0085] This comparative example uses the same petroleum coke gasification ash sample as in Example 1.

[0086] (1) 100 g of petroleum coke gasification ash sample was ball-milled and sieved, and a sample with a particle size range of 50-60 μm and an average particle size of 56.004 μm was selected and loaded into a fluidized bed chlorination reactor. After He gas was introduced into the chlorination reactor for purging, the temperature was raised to 600° C., and a chlorine / He gas mixture was introduced for chlorination reaction, and the reaction time was 30 min;

[0087] (2) After the reaction is completed, the chlorinated flue gas is condensed and recovered. Specifically, a part of the chlorinated flue gas is settled by gravity and the dust is collected. The remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. After the crude VOCl3 is refined, refined VOCl3 and a small amount of bottom slag 2 are obtained. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged.

[0088] (3) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a sodium hydroxide solution with a mass concentration of 0.5% is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0089] Comparative Example 5

[0090] This comparative example uses the same petroleum coke gasification ash sample as in Example 1.

[0091] (1) 100 g of petroleum coke gasification ash sample was ball-milled and sieved, and a sample with a particle size range of 70-80 μm and an average particle size of 77.316 μm was selected and loaded into a fluidized bed chlorination reactor. After He gas was introduced into the chlorination reactor for purging, the temperature was raised to 600° C., and a chlorine / He gas mixture was introduced for chlorination reaction, and the reaction time was 30 min;

[0092] (2) After the reaction is completed, the chlorinated flue gas is condensed and recovered. Specifically, a part of the chlorinated flue gas is settled by gravity and the dust is collected. The remaining chlorinated flue gas is condensed at 80-100°C to obtain crude FeCl3 and AlCl3 and condensed flue gas. The crude FeCl3 and AlCl3 and the dust are first heated to 200-250°C, and then condensed at 80-100°C to obtain refined FeCl3 and AlCl3 and a small amount of bottom slag 1. The condensed flue gas is collected by condensation heat exchange at 0-20°C to obtain crude VOCl3 and tail gas. After the crude VOCl3 is refined, refined VOCl3 and a small amount of bottom slag 2 are obtained. The residual chlorine in the tail gas is absorbed by alkali solution and then discharged.

[0093] (3) The chlorinated residue obtained by the chlorination reaction is washed and filtered to obtain a metal chloride filtrate and tailings. An excess of a sodium hydroxide solution with a mass concentration of 0.5% is added to the metal chloride filtrate to generate a precipitate, which is then filtered to obtain a crude nickel hydroxide product and saline wastewater. The tailings are roasted to obtain amorphous silicon aluminum powder.

[0094] Example 4

[0095] This embodiment is an application example of amorphous silicon aluminum powder as a raw material for building materials.

[0096] The amorphous silicon-aluminum powder obtained in the embodiment and the following raw materials are mixed and configured into a thermal insulation slurry according to the following formula: 580 kg of light calcium carbonate powder, 100 kg of amorphous silicon-aluminum powder, 25 kg of acrylate emulsion, 180 kg of alginate, 150 kg of hydroxypropyl methylcellulose sodium, 3 kg of polypropylene fiber, and 4 kg of preservative; first, the light calcium carbonate powder and the amorphous silicon-aluminum powder are sucked into a mixing and stirring tank by a vacuum negative pressure device for mixing and stirring, and then the acrylate emulsion, alginate, hydroxypropyl methylcellulose sodium, polypropylene fiber and preservative are sucked into the mixing and stirring tank by a vacuum negative pressure device, and finally mixed and stirred at room temperature to prepare a thermal insulation slurry.

[0097] Put the thermal insulation slurry, expanded perlite and polystyrene fine foam into the mixer container in a mass ratio of 1:0.16:0.026, mix and stir evenly to form a semi-solid paste. During on-site construction, put the semi-solid paste, ordinary Portland cement with a grade of P42.5 and water in a mass ratio of 1:0.45:0.50 into the mixing agitator, mix and stir evenly to obtain a hydrophobic composite thermal insulation mortar for exterior walls that meets the national A1 fire protection standard.

[0098] In the process of treating the petroleum coke gasification ash in the above embodiment, the specific surface area and the apparent structure morphology of the crushed petroleum coke gasification ash before and after the alkali dissolution treatment were measured respectively, and the data results shown in Table 1 and Figure 2 and Figure 3 The surface morphology shown in the figure is Figure 2 It can be seen that the sample before alkali treatment is blocky, with a smooth surface and no pore structure. Figure 3 It can be seen that after alkali dissolution treatment, the sample turned into a spherical shape and a large number of pores appeared on the surface. Combined with the changes in the specific surface area of ​​the sample before and after alkali dissolution in Table 1, it can be determined that alkali dissolution treatment can destroy the stable structure, increase the specific surface area of ​​the sample, and improve the fluidity of the sample by improving the shape of the sample microscopic particles, thereby making the sample more conducive to the operation of the subsequent fluidized bed chlorination reactor.

[0099] Table 1. Changes in specific surface area of ​​petroleum coke gasification ash samples before and after alkali dissolution treatment

[0100] serial number <![CDATA[Specific surface area before alkali treatment / m 2 / g]]> <![CDATA[Specific surface area after alkali treatment / m 2 / g]]> Example 1 3.8 89 Example 2 2.3 76 Example 3 6 103

[0101] In Example 1 and Comparative Examples 1-5, the conversion rate of each main component was calculated by measuring the content of each main component in the petroleum coke gasification ash sample and the obtained tailings, as shown in Table 2. As can be seen from the table, Comparative Examples 1-5 did not perform alkali dissolution treatment when treating the petroleum coke gasification ash, and the total conversion rate gradually increased as the particle size of the ash decreased. When the petroleum coke gasification ash was directly chlorinated without alkali dissolution treatment, a relatively ideal conversion rate could be achieved when the particle size was 2.154 μm, and the ash particles with an average particle size of 90 μm were chlorinated at 500°C after alkali dissolution treatment, and the effect of chlorination at 600°C was close to that of ash particles ground to 10 μm directly chlorinated, indicating that the increase in specific surface area and the improvement in the apparent morphology of the raw materials brought about by the alkali treatment process can greatly improve the efficiency of the chlorination reaction, and the particle size requirement of the ash can be increased from less than 10 μm to 90 μm, which significantly reduces the production cost and energy consumption brought about by industrial ash crushing, saving energy.

[0102] By measuring the composition analysis of the ash before and after alkali dissolution in Example 1, the results shown in Table 3 were obtained. When the petroleum coke gasification ash was treated with alkali dissolution using a dilute alkali solution, less silicon and aluminum were dissolved, and the dissolution rate of V2O5 was 17%. Through this step, a portion of the vanadium in the petroleum coke gasification ash was separated and recovered.

[0103] By measuring the contents of the main components of the filter residue after alkali dissolution in each example before and after the chlorination reaction, the conversion rate of each component in the chlorination reaction was calculated, and the results are shown in Table 4. It can be seen from the table that the main metals are effectively removed by the chlorination reaction of the petroleum coke gasification ash after alkali dissolution treatment, realizing the secondary utilization of solid waste.

[0104] Table 2. Conversion rates of main metal components

[0105]

[0106] Table 3. Analysis of main components of petroleum coke gasification ash before and after alkali dissolution in Example 1

[0107]

[0108]

[0109] Table 4. Results of ash chlorination reaction

[0110]

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present application, which should be included in the scope of the claims of the present application.

Claims

1. A method for treating heavy metal-containing silicon-aluminum-based waste slag, characterized in that: The method comprises (1) crushing the heavy metal silicon-aluminum-based waste residue to a particle size of less than 90 μm, adding it to an alkaline solution with a mass concentration of 3%-5%, reacting it at 100-180° C. for 2-3 hours, filtering it after the reaction, and obtaining an alkaline-dissolved filtrate and an alkaline-dissolved filter residue; wherein the mass ratio of the waste residue to the alkaline solution is 1:3-1:10; (2) treating the heavy metal-containing silicon-aluminum-based waste slag with alkali solution and filtering it, adding calcium salt to the filtrate, filtering it after the reaction is completed, and obtaining calcium vanadate slag; (3) the heavy metal-containing silicon-aluminum-based waste residue is treated with alkali and then filtered, and the obtained filter residue is washed and dried and then subjected to chlorination reaction; (4) obtaining chlorinated flue gas and chlorinated slag through a chlorination reaction, condensing and recovering the chlorinated flue gas to obtain one or more of iron chloride, aluminum chloride and vanadium chloride, washing and filtering the chlorinated slag to obtain a metal chloride filtrate and tailings; and roasting the tailings to obtain amorphous silicon aluminum powder; (5) When the heavy metal-containing silicon-aluminum-based waste slag contains heavy metal nickel, the method further comprises: adding alkali to the metal chloride filtrate, and filtering to obtain a crude nickel hydroxide product and saline wastewater after the reaction is completed; The heavy metal-containing silicon-aluminum-based waste slag is petroleum coke gasification ash, which contains heavy metal elements nickel, iron and vanadium; the petroleum coke gasification ash also contains at least one of the elements sodium, potassium, magnesium and calcium; the heavy metal-containing silicon-aluminum-based waste slag contains carbon.

2. The method for treating heavy metal-containing silicon-aluminum-based waste slag according to claim 1, characterized in that: The specific surface area of ​​the heavy metal-containing silicon-aluminum-based waste slag is not higher than 10m 2 / g.

3. The method for treating heavy metal-containing silicon-aluminum-based waste slag according to claim 1, characterized in that: The alkaline solution used in the alkaline dissolution treatment is an inorganic alkaline solution or a quaternary ammonium alkaline solution or a mixed solution of the two.

4. The method for treating heavy metal-containing silicon-aluminum-based waste slag according to claim 3, characterized in that: The inorganic base is one or more of sodium hydroxide, potassium hydroxide and ammonium hydroxide; and the quaternary ammonium base is tetramethylammonium hydroxide.

5. The method for treating heavy metal-containing silicon-aluminum-based waste slag according to claim 1, characterized in that: The temperature of the chlorination reaction is 500-650°C.

6. The method for treating heavy metal-containing silicon-aluminum-based waste slag according to claim 1, characterized in that: When the chlorinated flue gas is condensed and recovered, a part of the chlorinated flue gas is collected after settling by gravity, and the remaining chlorinated flue gas is condensed at 80-100°C to obtain at least one of the crude products of FeCl3 and AlCl3 and condensed flue gas; when the heavy metal silicon-aluminum-based waste slag contains heavy metal vanadium, the condensed flue gas is condensed at -20-0°C to obtain the crude VOCl3 product.

7. Amorphous silicon aluminum powder, characterized in that: The amorphous silicon-aluminum powder is prepared from silicon-aluminum-based waste slag containing heavy metals according to the method described in any one of claims 1-6.

8. Use of the amorphous silicon aluminum powder according to claim 7 as a raw material for building materials.

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