Succinimide leaching agent suitable for co-production of light calcium carbonate through CO2 indirect mineralization of alkaline solid waste

Abstract

The invention discloses a succinimide leaching agent suitable for co-production of light calcium carbonate through CO2 indirect mineralization of alkaline solid waste. The succinimide leaching agent is prepared from a main leaching agent succinimide and a solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 5-25 wt%. The succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste is simple in composition, high in calcium ion leaching efficiency, high in selectivity, low in leaching agent viscosity and capable of being recycled, and loss and cost of the leaching agent are reduced; in the mineralization stage, CO2 is promoted to be dissolved from a gas phase to a liquid phase, so that the reaction rate of the mineralization reaction is favorably improved, the production efficiency of calcium carbonate is improved, and the process cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of mineralization leaching, and in particular relates to a succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. Background Art

[0002] Excessive CO2 emissions have led to global warming, rising sea levels, and frequent natural disasters, posing a threat to human survival and development. Indirect mineralization technology is an important part of carbon capture, utilization and storage (CCUS) technology. It can simultaneously achieve CO2 storage and resource utilization of calcium-containing solid waste, and is a technology with great prospects.

[0003] However, there are still some problems with the leaching agents used in indirect mineralization, and traditional indirect mineralization leaching agents (ammonium chloride, ammonium acetate, sodium hydroxide, etc.) still have some problems. Most traditional indirect mineralization leaching agents only have the function of leaching calcium ions. The chemical reagents cannot be recycled after application, and a subsequent regeneration process is required to regenerate the leaching solution, which increases the cost of indirect mineralization and makes it difficult to apply it industrially. In order to solve the above problems, researchers have developed a series of recyclable leaching agents to reduce the cost of indirect mineralization. The patent with publication number CN115650274A discloses a method for liquid phase indirect mineralization of solid waste gypsum with tyrosine as an additive. The method uses potassium hydroxide to dissolve tyrosine and deprotonate tyrosine at the same time to make the solution have a certain alkalinity; the deprotonated tyrosine solution is used to leach the waste gypsum and obtain a calcium-enriched solution, and carbon dioxide is introduced into the calcium-enriched solution to precipitate calcium ions and tyrosine at the same time, and potassium hydroxide is added to the precipitation mixture to dissolve tyrosine again to obtain a relatively pure calcium carbonate product. Patent publication number CN115784285A discloses a method for preparing nano-calcium carbonate by indirect mineralization of carbide slag with CO2. The method uses ammonium acetate as a leaching agent, stirs and filters the carbide slag in an ammonium acetate solution to obtain a calcium-enriched solution, introduces CO2 into the calcium-enriched solution and adds a dispersant, and continues stirring until the pH drops to 7 to terminate the reaction, and obtains nano-calcium carbonate after solid-liquid separation.

[0004] However, ammonium salt leaching agents are prone to ammonia escape during the leaching process, resulting in chemical reagent loss and increased production costs. Amino acids are expensive, and their solubility is greatly affected by the pH of the solution. They are prone to amino acid loss during the leaching and mineralization stages of indirect mineralization, resulting in high costs for indirect mineralization. In addition, the above-mentioned leaching agents often undergo coordination effects with the heterometallic ions in the solid waste during leaching to generate colored precipitates, resulting in reduced purity and whiteness of the calcium carbonate generated by indirect mineralization. Summary of the invention

[0005] The purpose of the present invention is to provide a succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. The succinimide leaching agent can be recycled to reduce loss and cost. Applying it to the leaching and mineralization of calcium-containing solid waste can improve the leaching efficiency and selectivity of calcium ions and increase the reaction rate of the mineralization reaction.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0007] A succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 5-25wt%.

[0008] Preferably, the concentration of the main leaching agent succinimide in the succinimide leaching agent is 5wt%.

[0009] Preferably, the concentration of the main leaching agent succinimide in the succinimide leaching agent is 10wt%.

[0010] Preferably, the concentration of the main leaching agent succinimide in the succinimide leaching agent is 15wt%.

[0011] Preferably, the concentration of the main leaching agent succinimide in the succinimide leaching agent is 20wt%.

[0012] Preferably, the concentration of the main leaching agent succinimide in the succinimide leaching agent is 25wt%.

[0013] In the present invention, succinimide can absorb and release protons during leaching and mineralization, thereby achieving better cycle performance.

[0014] In the present invention, both leaching and mineralization occur at relatively low temperatures, thus effectively reducing solvent loss due to volatilization.

[0015] The leaching agent of the present invention can be adsorbed on the surface of calcium carbonate crystals in the mineralization stage, and has an impact on the crystal form of calcium carbonate, and can be directionally regulated to prepare high-value-added vaterite crystal calcium carbonate.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste of the present invention has a simple composition, high leaching efficiency and selectivity for calcium ions, low viscosity and recyclable leaching agent, which reduces the loss and cost of the leaching agent; the mineralization stage promotes the dissolution of CO2 from the gas phase to the liquid phase, which is beneficial to improving the reaction rate of the mineralization reaction, improving the calcium carbonate production efficiency, and reducing the process cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram of a leaching experimental device for applying the succinimide leaching agent of the present invention to CO2 indirect mineralization;

[0019] Figure 2 This is a diagram of a mineralization experimental device for applying the succinimide leaching agent of the present invention to indirect CO2 mineralization;

[0020] Figure 3 This is a surface SEM image of calcium carbonate obtained by applying succinimide leaching agent to CO2 indirect mineralization in Example 5;

[0021] Figure 4 This is the XRD characterization diagram of calcium carbonate obtained by applying succinimide leaching agent to CO2 indirect mineralization in Example 5;

[0022] Figure 5 This is a surface SEM image of the steel slag used in the embodiment of the present invention before leaching;

[0023] Figure 6 This is a surface SEM image of the steel slag used in the embodiment of the present invention after leaching;

[0024] In the attached figure, 1. constant temperature magnetic stirring water bath, 2. three-necked flask, 3. pH meter, 4. vacuum filter; 5. CO2 gas cylinder, 6. mass flow meter. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] A succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 5wt%.

[0028] Example 2

[0029] A succinimide leaching agent suitable for indirect mineralization of alkaline solid waste by CO2 to produce light calcium carbonate. The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 10wt%.

[0030] Example 3

[0031] A succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 15wt%.

[0032] Example 4

[0033] A succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 20wt%.

[0034] Example 5

[0035] A succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate. The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 25wt%.

[0036] The leaching agent prepared in the above embodiment is applied to the leaching and mineralization of calcium-containing solid waste. The specific application process is as follows: Figure 1 As shown, the leaching agent prepared in the above example is added to the steel slag in proportion, and the stirring is stopped after stirring for 1 hour, and the leached calcium-rich solution is obtained by suction filtration; Figure 2 As shown, the calcium-rich solution is transferred to another reaction vessel, and CO2 is introduced into the calcium-rich solution to obtain pure white calcium carbonate precipitate. The leaching and mineralization reaction parameters are shown in Table 1:

[0037] Table 1 Parameters of leaching and mineralization reaction of calcium-containing solid waste

[0038]

[0039] The above-mentioned experimental device and experimental method were used to conduct experiments on the succinimide leaching agent formulations of the present invention numbered 1 to 5 to illustrate the performance of the calcium-containing solid waste leaching agent of the present invention. The formulations and test results are shown in Table 2:

[0040] Table 2 Leaching test results of succinimide leaching agent of the present invention

[0041]

[0042] The succinimide leaching agent prepared in Example 5 was tested at different leaching temperatures. The experimental results are shown in Table 3 below:

[0043] Table 3 Test results of the leaching agent prepared in Example 5 at different leaching temperatures

[0044]

[0045] Table 4 EDS+mapping characterization results of calcium carbonate obtained by indirect CO2 mineralization using the leaching agent prepared in Example 5

[0046]

[0047] From the test results in Table 2, it can be seen that the leaching efficiency of the leaching agent of the present invention is 23.60% at a temperature of 30°C; and the leaching efficiency increases with the increase of temperature. As shown in Table 3, the leaching efficiency can reach 43.07% at most, which is much higher than that of the proton amine leaching agent (the leaching efficiency of proton amine is about 18%). 2+ The leaching selectivity is above 99%, indicating that the main component of the leaching agent, succinimide, can ensure the leaching efficiency and leaching selectivity of the leaching agent of the present invention for calcium-containing solid waste. Figure 3 It can be seen from the SEM and EDS characterization results in Table 4 that the prepared calcium carbonate is a spherical crystal calcium carbonate with a particle size of 0.5-2um. Characterization and analysis show that the impurities present in the calcium carbonate are only 0.04% of Mg element, and the purity of calcium carbonate is higher than 99.9%. Figure 4 XRD characterization analysis confirmed that all calcium carbonate is vaterite, which has the highest economic value, and there is no other crystal form. Figure 5 Figure and Figure 6 As shown, the mineral surface structure of the steel slag is dense before leaching, and honeycomb-like pores appear on the surface after leaching, indicating that the leaching agent of the present invention can selectively leach the active calcium component in the steel slag.

[0048] In summary, the present invention provides a succinimide leaching agent formula with excellent comprehensive performance. The leaching agent has high selectivity for calcium-containing solid waste and is recyclable. Its component raw materials are easy to obtain and the loss of chemical reagents is low. It has cost advantages when applied to chemical production and has industrial practicability.

[0049] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention.

Claims

1. A succinimide leaching agent suitable for indirect CO2 mineralization of alkaline solid waste and co-production of light calcium carbonate, characterized in that: The succinimide leaching agent is prepared from a main leaching agent succinimide and solvent water; the concentration of the main leaching agent succinimide in the succinimide leaching agent is 5-25wt%.

2. A succinimide leaching agent suitable for CO2 indirect mineralization of alkaline solid waste and co-production of light calcium carbonate according to claim 1, characterized in that: The concentration of the main leaching agent succinimide in the succinimide leaching agent is 5wt%.

3. The succinimide leaching agent suitable for indirect CO2 mineralization of alkaline solid waste and co-production of light calcium carbonate according to claim 1, characterized in that: The concentration of the main leaching agent succinimide in the succinimide leaching agent is 10wt%.

4. The succinimide leaching agent suitable for indirect CO2 mineralization of alkaline solid waste and co-production of light calcium carbonate according to claim 1, characterized in that: The concentration of the main leaching agent succinimide in the succinimide leaching agent is 15wt%.

5. The succinimide leaching agent suitable for indirect CO2 mineralization of alkaline solid waste and co-production of light calcium carbonate according to claim 1, characterized in that: The concentration of the main leaching agent succinimide in the succinimide leaching agent is 20wt%.

6. The succinimide leaching agent suitable for indirect CO2 mineralization of alkaline solid waste and co-production of light calcium carbonate according to claim 1, characterized in that: The concentration of the main leaching agent succinimide in the succinimide leaching agent is 25wt%.

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