Aluminum sulfate reactive crystallization preparation method for accelerator and preparation line thereof

Abstract

The invention discloses an aluminum sulfate reactive crystallization preparation method for an accelerator and a preparation line thereof, and the preparation method comprises the following steps: 1, carrying out a chemical reaction on corresponding amounts of aluminum hydroxide and sulfuric acid to generate an aluminum sulfate solution; 2, evaporating and concentrating the aluminum sulfate solution to form a supersaturated solution; step 3, performing temperature-controlled cooling on the aluminum sulfate solution in a supersaturated state, and separating out aluminum sulfate crystals; step 4, collecting precipitated aluminum sulfate crystals, and sequentially drying and crushing; and 5, screening the crushed aluminum sulfate crystals. The purity of the prepared aluminum sulfate crystal can be guaranteed, the utilization rate and the application effect of the aluminum sulfate crystal are guaranteed, and meanwhile the influence of preparation and production activities on the environment can be reduced.

Description

Technical Field

[0001] The invention relates to the field of aluminum sulfate preparation, and in particular to a method for preparing aluminum sulfate reaction crystallization for an accelerator and a preparation line thereof. Background Art

[0002] Liquid alkali-free accelerator is an additive used in shotcrete, and its main ingredients include aluminum sulfate, polymer-modified nanoparticles, activated alumina, etc. Its preparation method usually involves mixing various ingredients in a certain proportion and reacting them under specific conditions to form a stable liquid accelerator.

[0003] Among them, the purity, crystal morphology and particle size distribution of aluminum sulfate directly affect its reactivity with the cement system and the coagulation effect. The traditional method of preparing aluminum sulfate usually uses bauxite and sulfuric acid to prepare aluminum sulfate. The raw material cost is low but the iron content is high (up to 0.5% or more), and it is difficult to remove it through conventional processes, resulting in limited product purity. At the same time, the traditional process has high energy consumption, long production cycle, and low recovery rate of fine powder after screening, which restricts the efficiency of industrialization. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing aluminum sulfate reaction crystallization for an accelerator and a preparation line thereof, wherein the method and the preparation line thereof can ensure the purity of the prepared aluminum sulfate crystals, and guarantee the utilization rate and application effect of the aluminum sulfate crystals, and can also reduce the impact of the preparation and production activities on the environment.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] A method for preparing aluminum sulfate reaction crystallization for an accelerating setting agent comprises the following steps:

[0007] Step 1, chemically reacting corresponding amounts of aluminum hydroxide and sulfuric acid to generate an aluminum sulfate solution;

[0008] Step 2, evaporating and concentrating the aluminum sulfate solution to form a supersaturated solution;

[0009] Step 3, cooling the supersaturated aluminum sulfate solution under temperature control to precipitate aluminum sulfate crystals;

[0010] Step 4, collecting the precipitated aluminum sulfate crystals, and drying and crushing them in sequence;

[0011] Step five, screening the crushed aluminum sulfate crystals.

[0012] As a further improvement of the above technical solution, in step 1, the concentration of sulfuric acid is 60%-70%, the temperature for the chemical reaction between aluminum hydroxide and sulfuric acid is 80-100°C, and the pH is 1.5-2.

[0013] As a further improvement of the above technical solution, in step three, the temperature of the aluminum sulfate solution is cooled to 20-30°C, and the cooling rate is not higher than 5°C / h.

[0014] As a further improvement of the above technical solution, in step three, a small amount of high-purity aluminum sulfate seed crystals are added to the aluminum sulfate solution at the initial cooling stage.

[0015] As a further improvement of the above technical solution, in step 4, the drying temperature of the aluminum sulfate crystals is 80-90°C.

[0016] As a further improvement of the above technical solution, the step 4 is specifically as follows:

[0017] Filter the aluminum sulfate solution treated in step 3 to collect aluminum sulfate crystals with a particle size of not less than 80 mesh;

[0018] The filtered aluminum sulfate solution is mixed into the aluminum sulfate solution in step 2.

[0019] As a further improvement of the above technical solution, in step five, the particle size of the screened aluminum sulfate crystals is 80-120 mesh.

[0020] As a further improvement of the above technical solution, the step five is specifically as follows:

[0021] Screen out the aluminum sulfate crystals with a particle size greater than 120 mesh from the crushed aluminum sulfate crystals, and perform step 4 separately;

[0022] Screening out aluminum sulfate crystals with a particle size between 80 mesh and 120 mesh from the screened aluminum sulfate crystals again, and collecting them;

[0023] The aluminum sulfate crystals after secondary screening are uniformly recovered.

[0024] The present invention also provides a preparation line for the reaction crystallization preparation method of aluminum sulfate for accelerating setting agent based on any one of the above technical solutions, comprising:

[0025] A reaction device, which is used for aluminum hydroxide and sulfuric acid to react chemically and generate aluminum sulfate solution;

[0026] A concentrating device, which is used to evaporate and concentrate the aluminum sulfate solution to form a supersaturated solution;

[0027] A crystallization device, which is used to control the temperature and cool the supersaturated aluminum sulfate solution to precipitate aluminum sulfate crystals;

[0028] A processing device, which is used to collect the precipitated aluminum sulfate crystals and sequentially dry and crush them;

[0029] The screening device is used to screen the particle size of the aluminum sulfate crystals after the crushing process.

[0030] Compared with the prior art, the present invention has the following advantages and effects:

[0031] (1) The present invention adopts an integrated connection setting of reaction-concentration-crystallization-post-treatment, which shortens the production cycle (reduced by 30% compared with the traditional process) and reduces energy consumption (energy consumption per unit product ≤ 0.8 tons of standard coal / ton). At the same time, it ensures the purity of the prepared aluminum sulfate crystals and reduces the impact of the preparation and production activities on the environment, thereby reducing the environmental load.

[0032] (2) The present invention forms a controllable supersaturated solution by evaporating and concentrating the aluminum sulfate solution, and combines temperature-controlled cooling to improve the crystal density and crystal integrity, thereby ensuring the quality of the prepared aluminum sulfate crystals and thus ensuring the use effect of the subsequent accelerated setting agent.

[0033] (3) The present invention sequentially dries, crushes and screens aluminum sulfate crystals, thereby optimizing the physical properties (i.e., moisture content and particle size) of the aluminum sulfate crystals and also separately recovering aluminum sulfate crystals of different particle size ranges, thereby ensuring the utilization rate and application effect of the aluminum sulfate crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The invention discloses a structural schematic diagram of a method for preparing an accelerating setting agent by reaction crystallization of aluminum sulfate.

[0035] Figure 2 The present invention is a schematic diagram of the process structure of a method for preparing an accelerating setting agent by reaction crystallization of aluminum sulfate.

[0036] Figure 3 yes Figure 1 The structural diagram of step four is shown in FIG.

[0037] Figure 4 yes Figure 1 The structural diagram of step five is shown in FIG.

[0038] Figure 5 The invention discloses a structural schematic diagram of an aluminum sulfate reaction crystallization preparation line for an accelerator.

[0039] Among them, there are a reaction device 1, a concentration device 2, a crystallization device 3, a processing device 4, and a screening device 5. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0041] Embodiment 1.

[0042] See also Figure 1-Figure 4 The present embodiment provides a method for preparing aluminum sulfate for accelerating setting agent by reaction crystallization, comprising the following steps:

[0043] Step 1, chemically reacting corresponding amounts of aluminum hydroxide and sulfuric acid to generate an aluminum sulfate solution;

[0044] Step 2, evaporating and concentrating the aluminum sulfate solution to form a supersaturated solution;

[0045] Step 3, cooling the supersaturated aluminum sulfate solution under temperature control to precipitate aluminum sulfate crystals;

[0046] Step 4, collecting the precipitated aluminum sulfate crystals, and drying and crushing them in sequence;

[0047] Step five, screening the crushed aluminum sulfate crystals.

[0048] In this embodiment, in step 1, the concentration of sulfuric acid is 60%-70%, the temperature for the chemical reaction between aluminum hydroxide and sulfuric acid is 80-100°C, and the pH is 1.5-2, which can improve the reaction efficiency while reducing the occurrence of side reactions.

[0049] In this embodiment, in step three, the temperature of the aluminum sulfate solution is cooled to 20-30°C, and the cooling rate is no higher than 5°C / h, thereby reducing the occurrence of fine grains caused by rapid cooling.

[0050] In this embodiment, in step three, a small amount of high-purity aluminum sulfate seed crystals are added to the aluminum sulfate solution at the initial stage of cooling, which accelerates crystallization and also helps to improve the crystal morphology.

[0051] In this embodiment, in step 4, the drying temperature of the aluminum sulfate crystals is 80-90° C., which reduces the risk of decomposition of the aluminum sulfate crystals due to high temperature.

[0052] See also Figure 3 , the step 4 is specifically as follows:

[0053] The aluminum sulfate solution treated in step 3 is filtered, and aluminum sulfate crystals having a particle size of not less than 80 mesh are collected and dried and crushed in sequence;

[0054] The filtered aluminum sulfate solution is mixed into the aluminum sulfate solution in step 2, thereby improving the utilization rate of the aluminum sulfate solution.

[0055] In this embodiment, in step five, the particle size of the aluminum sulfate crystals screened out is 80-120 mesh.

[0056] See also Figure 4 , the step five is specifically as follows:

[0057] Screen out the aluminum sulfate crystals with a particle size greater than 120 mesh from the crushed aluminum sulfate crystals, and perform step 4 separately to avoid repeated crushing resulting in excessively fine powder;

[0058] Screening out aluminum sulfate crystals with a particle size between 80 mesh and 120 mesh from the screened aluminum sulfate crystals again, and collecting them;

[0059] The aluminum sulfate crystals after secondary screening are uniformly recovered.

[0060] By screening out aluminum sulfate crystals in different particle size ranges, the utilization rate of the aluminum sulfate crystals is improved and waste is reduced while ensuring the subsequent application effect of the aluminum sulfate crystals.

[0061] Embodiment 2.

[0062] See also Figure 5 The present embodiment provides a preparation line based on the preparation method of aluminum sulfate reaction crystallization for accelerating setting agent described in the first embodiment, comprising:

[0063] A reaction device 1, which is used for aluminum hydroxide and sulfuric acid to react chemically and generate an aluminum sulfate solution;

[0064] A concentrator 2, which is used to evaporate and concentrate the aluminum sulfate solution to form a supersaturated solution;

[0065] A crystallization device 3, which is used to control the temperature and cool the aluminum sulfate solution in a supersaturated state to precipitate aluminum sulfate crystals;

[0066] A processing device 4 is used to collect the precipitated aluminum sulfate crystals and sequentially dry and crush them;

[0067] The screening device 5 is used to screen the particle size of the aluminum sulfate crystals after the crushing process.

[0068] The above contents described in this specification are merely examples of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, as long as they do not deviate from the contents of the present specification or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing aluminum sulfate reaction crystallization for accelerating setting agent, characterized in that: The steps include: Step 1, chemically reacting corresponding amounts of aluminum hydroxide and sulfuric acid to generate an aluminum sulfate solution; Step 2, evaporating and concentrating the aluminum sulfate solution to form a supersaturated solution; Step 3, cooling the supersaturated aluminum sulfate solution under temperature control to precipitate aluminum sulfate crystals; Step 4, collecting the precipitated aluminum sulfate crystals, and drying and crushing them in sequence; Step five, screening the crushed aluminum sulfate crystals.

2. The method for preparing the aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: In the step 1, the concentration of sulfuric acid is 60%-70%, the temperature for the chemical reaction between aluminum hydroxide and sulfuric acid is 80-100° C., and the pH is 1.5-2.

3. The method for preparing aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: In the step 3, the temperature of the aluminum sulfate solution is cooled to 20-30° C., and the cooling rate is not higher than 5° C. / h.

4. The method for preparing aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: In the step 3, a small amount of high-purity aluminum sulfate seed crystals are added to the aluminum sulfate solution at the initial cooling stage.

5. The method for preparing aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: In the step 4, the drying temperature of the aluminum sulfate crystals is 80-90°C.

6. The method for preparing aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: The step 4 is specifically as follows: Filter the aluminum sulfate solution treated in step 3 to collect aluminum sulfate crystals with a particle size of not less than 80 mesh; The filtered aluminum sulfate solution is mixed into the aluminum sulfate solution in step 2.

7. The method for preparing aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: In the step 5, the particle size of the aluminum sulfate crystals screened out is 80-120 mesh.

8. The method for preparing aluminum sulfate reaction crystallization for accelerating setting agent according to claim 1, characterized in that: The step five is specifically as follows: Screen out the aluminum sulfate crystals with a particle size greater than 120 mesh from the crushed aluminum sulfate crystals, and perform step 4 separately; Screening out aluminum sulfate crystals with a particle size between 80 mesh and 120 mesh from the screened aluminum sulfate crystals again, and collecting them; The aluminum sulfate crystals after secondary screening are uniformly recovered.

9. A production line based on the preparation method of aluminum sulfate reaction crystallization for accelerating setting agent according to any one of claims 1 to 8, characterized in that: include: A reaction device, which is used for aluminum hydroxide and sulfuric acid to react chemically and generate aluminum sulfate solution; A concentrating device, which is used to evaporate and concentrate the aluminum sulfate solution to form a supersaturated solution; A crystallization device, which is used to control the temperature and cool the supersaturated aluminum sulfate solution to precipitate aluminum sulfate crystals; A processing device, which is used to collect the precipitated aluminum sulfate crystals and sequentially dry and crush them; The screening device is used to screen the particle size of the aluminum sulfate crystals after the crushing process.

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