阅读说明：本技术 一种具有炭缺陷位结构的生物炭吸附剂及其制备方法与应用 (Charcoal adsorbent with carbon defect site structure and preparation method and application thereof ) 是由 胡晖 吕晨光 汪湉 张佳源 于 2021-08-24 设计创作，主要内容包括：本发明属于炭材料领域,具体涉及一种具有炭缺陷位结构的生物炭吸附剂制备的方法及应用。制备过程包括以下步骤：(1)制粒：将洗净、干燥的笋壳粉碎,过筛,备用；(2)预制：取适量笋壳在限氧的条件下对其进行预处理(3)转制：炭化后的笋壳炭与转制剂按一定质量比例添加于研钵中,混合,研磨均匀,在惰性气体保护下进行高温转制。(4)精制：高温转制的生物炭冷却至室温后,使用精制液对其进行精制,过滤,并用去离子水洗涤至滤液为中性,以制得一种具有炭缺陷位结构的生物炭材料,可以用于吸附回收酸性废液中金属铼。(The invention belongs to the field of carbon materials, and particularly relates to a preparation method and application of a charcoal adsorbent with a carbon defect site structure. The preparation process comprises the following steps: (1) and (3) granulating: pulverizing cleaned and dried bamboo shoot shell, and sieving; (2) prefabrication: taking a proper amount of bamboo shoot shells, and carrying out pretreatment (3) conversion on the bamboo shoot shells under the condition of oxygen limitation: adding the carbonized bamboo shoot shell carbon and the conversion agent into a mortar according to a certain mass ratio, mixing, uniformly grinding, and carrying out high-temperature conversion under the protection of inert gas. (4) Refining: and cooling the biochar converted at high temperature to room temperature, refining the biochar by using a refining solution, filtering, and washing by using deionized water until filtrate is neutral to prepare the biochar material with a carbon defect site structure, wherein the biochar material can be used for adsorbing and recovering metal rhenium in acid waste liquid.)

1. A preparation method of a charcoal adsorbent with a charcoal defect site structure is characterized by comprising the following steps: the method comprises the following steps:

1) and (3) granulating: pulverizing cleaned and dried bamboo shoot shell, and sieving to obtain bamboo shoot shell granule;

2) prefabrication: performing prefabrication treatment on the bamboo shoot shells treated in the step 1) under the condition of oxygen limitation;

3) transferring: adding the bamboo shoot shell biochar prepared in the step 2) and a conversion agent into a mortar according to a certain mass ratio, mixing, uniformly grinding, and carrying out high-temperature conversion under the protection of protective gas;

4) refining: refining the biochar obtained in the step 3) by using a refining liquid, filtering, washing by using deionized water until the filtrate is neutral, and drying to obtain the biochar adsorbent with the carbon defect site structure.

2. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: in the step 1), the bamboo shoot shells are crushed and then sieved by a 20-100-mesh sieve, and the drying temperature is 60-100 ℃.

3. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: the prefabrication treatment in the step 2) is high-temperature heating treatment, the temperature is 100 ℃ and 600 ℃, the time is 1-3 h, and the oxygen content of the limited oxygen is 1-12 vol%.

4. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the biochar adsorbent is prepared by the following steps: in the step 3), the transfer agent is potassium acetate.

5. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: in the step 3), the mixing mass ratio of the bamboo shoot shell biochar prepared in the step 2) to the conversion agent is 1:1-1: 4.

6. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: in the step 3), the transfer temperature is 500-.

7. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: in the step 3), the protective gas is one of nitrogen, argon and carbon dioxide, and the flow rate is 50-150 mL/min.

8. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: in the step 4), the refining solution is one or more of hydrochloric acid, nitric acid or sulfuric acid, and H⁺The concentration is 0.1-5 mol/L, the mass ratio of the volume of the refined liquid to the biochar is 20-30 ml: 1g, refining for 10-30 min.

9. The method for preparing the biochar adsorbent with the carbon defect site structure as claimed in claim 1, wherein the method comprises the following steps: in the step 4), the drying temperature is 40-100 ℃.

10. Use of the charcoal adsorbent having carbon defect site structure prepared by the method according to any one of claims 1 to 9 for adsorbing and recovering rhenium metal in acid waste liquid.

Technical Field

The invention belongs to the field of carbon materials, and particularly relates to a preparation method and application of a charcoal adsorbent with a carbon defect site structure.

Background

Rhenium is a rare metal, has the characteristics of corrosion resistance, high temperature resistance, high hardness and good catalytic performance, and is widely applied to the fields of national defense, aerospace, aviation, catalysis and the like. However, the rhenium reserves are limited and scarce, the average content of rhenium in the crust is only ppb and no trace of rhenium is detected which is often associated with the industrial exploitation of single rhenium-containing ores, molybdenite and bornite. Rhenium becomes one of important strategic resources in China, however, rhenium resources in China are deficient, and the demand of national defense, science and technology and high and new technology for rapid development on rhenium is far higher than the existing reserve quantity of rhenium. The improvement has important significance for the recovery of rhenium in primary and secondary resources.

In pyrometallurgy, trace rhenium dispersed in copper concentrate finally enters copper smelting acid waste liquid in a form of Re (VII) after high-temperature oxidation and washing processes, and the waste liquid has the characteristics of low rhenium content, strong acidity and complex coexisting ions, so that how to selectively recover rhenium from the copper smelting acid waste liquid with high efficiency becomes a focus of increasing attention of researchers.

At present, methods for recovering and separating rhenium from waste liquid mainly comprise a solvent extraction method, an ion exchange method and a chemical precipitation method, but the three methods cannot separate and recover low-concentration rhenium in the waste liquid, and the low-concentration rhenium in the waste liquid needs to be subjected to enrichment pretreatment to improve the initial concentration of rhenium, and then can be separated and extracted. The adsorption method has the characteristics of simple process, convenient operation and direct application to adsorption and separation of low-concentration rhenium in waste liquid, and is widely concerned by researchers. In the adsorption method, the carbon material is often used as an adsorbent for adsorbing and separating metal ions in waste liquid due to the characteristics of simple preparation process, wide raw materials, low price and the like. However, the carbon material has no selective adsorption capacity on Re (VII) in the waste liquid under the influence of the physicochemical property of the carbon material when the carbon material is used as an adsorbent. The disorder degree of the carbon material structure is improved, and the defect sites of the carbon material are increased, so that the selective adsorption capacity of the carbon material on hydrophobic ions Re (VII) in the waste liquid is enhanced. It is therefore essential to select a suitable method for activating the carbon material to improve its selectivity to rhenium.

Disclosure of Invention

The invention aims to provide a biochar adsorbent with a carbon defect site structure, which is low in cost and simple in preparation method, and application of the biochar adsorbent in adsorption recovery of metal rhenium in acid waste liquid.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a charcoal adsorbent with a charcoal defect site structure comprises the following steps:

1) and (3) granulating: pulverizing cleaned and dried bamboo shoot shell, and sieving to obtain bamboo shoot shell granule;

2) prefabrication: taking a proper amount of bamboo shoot shells treated in the step 1) for prefabricating treatment under the condition of limiting oxygen;

3) transferring: taking a proper amount of the bamboo shoot shell biochar prepared in the step 2), adding the bamboo shoot shell biochar and a conversion agent into a mortar according to a certain mass ratio, mixing, uniformly grinding, and carrying out high-temperature conversion under the protection of protective gas;

4) refining: refining the biochar obtained in the step 3) by using a refining liquid, filtering, washing by using deionized water until the filtrate is neutral, and drying to obtain the biochar adsorbent with the carbon defect site structure.

In the step 1), the bamboo shoot shells are crushed and then sieved by a 20-100-mesh sieve, and the drying temperature is 60-100 ℃.

The prefabricating temperature in the step 2) is 100-.

In the step 3), the transfer agent is potassium acetate, the mixing mass ratio of the bamboo shoot shell biochar prepared in the step 2) to the transfer agent is 1:1-1:4, the transfer temperature is 500-800 ℃, the transfer time is 1-3 h, the protective gas is one of nitrogen, argon and carbon dioxide, and the flow rate is 50-150 mL/min.

In the step 4), the biochar obtained in the step 3 is placed in a beaker and thenAdding a certain amount of refined solution into a beaker, placing the beaker into a water bath constant temperature oscillator, oscillating for a period of time at the temperature of 25 ℃ and the oscillation speed of 120rpm, taking out, filtering, and washing with deionized water until the filtrate is neutral. The refining solution is one or more of hydrochloric acid, nitric acid or sulfuric acid, and H⁺The concentration is 0.1-5 mol/L, the drying temperature is 40-100 ℃, the mass ratio of the volume of the refined liquid to the biochar is 20-30 ml: 1g, refining for 10-30 min.

The charcoal adsorbent with the carbon defect site structure is applied to high-efficiency selective adsorption and separation of scattered metal rhenium in waste liquid, and the main adsorption mechanism of rhenium in the charcoal adsorption solution with the carbon defect site structure is the interaction between an electron acceptor and a donor.

The invention has the beneficial effects and outstanding advantages that:

1. the invention takes the bamboo shoot shells which are large agricultural and forestry wastes as the raw material of the adsorbent, has wide sources and low cost, and can lighten the environmental burden and achieve the aim of changing waste into valuables;

2. under the high-temperature condition, the conversion agent etches the bamboo shoot shell biochar, so that the disorder degree of the bamboo shoot shell biochar structure is improved, carbon defect sites in the bamboo shoot shell biochar structure are increased, and the selective adsorption capacity of the bamboo shoot shell biochar material on rhenium in acid waste liquid is improved.

3. The biochar adsorbent with the carbon defect site structure is used for separating rhenium from the acidic waste liquid, the recovery rate is more than 96%, the selectivity of rhenium in the binary ion coexisting waste liquid is up to 86%, and the selectivity of rhenium in the multi-ion coexisting waste liquid is up to 77%. Can realize the high-efficiency selective separation and recovery of rhenium in the acid waste liquid.

Drawings

FIG. 1 is Raman diagram of raw charcoal and charcoal with carbon defect site structure prepared by the present invention;

FIG. 2 is XRD pattern of undisturbed biochar and biochar with carbon defect site structure prepared by the present invention.

Detailed Description

Example 1

A preparation method and application of a charcoal adsorbent with a charcoal defect site structure comprise the following steps:

(1) and (3) granulating: crushing the washed and dried bamboo shoot shells, and sieving the crushed bamboo shoot shells with a 60-mesh sieve;

(2) prefabrication: taking a proper amount of sieved bamboo shoot shells, placing the bamboo shoot shells in a muffle furnace, prefabricating for 4 hours at 500 ℃, cooling to room temperature, taking out, washing to be neutral, and drying to obtain bamboo shoot shell biochar;

(3) transferring: mixing 0.2 g bamboo shoot shell charcoal and 0.6 g CH₃COOK in mortar, mixing, grinding, placing in a tube furnace with program temperature control, and introducing N₂The flow rate was 60 mL/min and the rotation was carried out at 700 ℃ for 2 h. (ii) a

(4) Refining: and (3) placing the converted biochar in a beaker, adding 20mL of HCl with the concentration of 2moL/L into the beaker, placing the beaker in a water bath constant temperature oscillator, oscillating for 20min at the temperature of 25 ℃ and the oscillation speed of 120rpm, taking out, filtering, and washing with deionized water until the filtrate is neutral.

Application example 1

Adding 0.008g of bamboo shoot shell biochar into 100 mL of solution with rhenium concentration of 20 mg/L for adsorption experiment, wherein the adsorption quantity after adsorption balance is 14 mg/g; 0.008g of the biochar material with the carbon defect site structure is added into 100 mL of solution with rhenium concentration of 20 mg/L for adsorption experiment, and the adsorption quantity after adsorption equilibrium is 238 mg/g. Adding 0.008g of bamboo shoot shell biochar into 200 mL of solution with the rhenium concentration of 10 mg/L for adsorption experiment, wherein the adsorption quantity after adsorption balance is 6 mg/g; 0.008g of the biochar material with the carbon defect site structure is added into 200 mL of solution with the rhenium concentration of 10 mg/L for adsorption experiment, and the adsorption quantity after adsorption equilibrium is 225 mg/g.

Application example 2

Adding 0.008g of bamboo shoot shell biochar material into 100 mL of NO-containing biochar material₃ ^-And ReO₄ ^-In solution with coexisting binary ions, NO₃ ^-Molar concentration of ReO₄ ^-The adsorption efficiency of the bamboo shoot shell biochar selective adsorption solution Re (VII) is only 2 percent. 0.008g of biochar material with carbon defect site structure is added into 100 mL of biochar material containing NO₃ ^-And ReO₄ ^-In solution with coexisting binary ions, NO₃ ^-Molar concentration of ReO₄ ^-The adsorption efficiency of the biochar selective adsorption solution Re (VII) with the carbon defect site structure is more than 83 percent. Adding 0.008g of bamboo shoot shell biochar material into 100 mL of SO-containing biochar material₄ ^2-And ReO₄ ^-In a binary ion coexisting solution, SO₄ ^2-Molar concentration of ReO₄ ^-The adsorption efficiency of the bamboo shoot shell biochar selective adsorption solution Re (VII) is only 3 percent. 0.008g of biochar material with carbon defect site structure is added into 100 mL of biochar material containing SO₄ ^2-And ReO₄ ^-In a binary ion coexisting solution, SO₄ ^2-Molar concentration of ReO₄ ^-The adsorption efficiency of the biochar selective adsorption solution Re (VII) with the carbon defect site structure is over 86 percent. Adding 0.008g of bamboo shoot shell biochar material into 100 mL of PO-containing material₄ ^3-And ReO₄ ^-In a binary ion coexisting solution, PO₄ ^3-Molar concentration of ReO₄ ^-The adsorption efficiency of the bamboo shoot shell biochar selective adsorption solution Re (VII) is only 5 percent. 0.008g of biochar material with carbon defect site structure is added into 100 mL of PO-containing material₄ ^3-And ReO₄ ^-In a binary ion coexisting solution, PO₄ ^3-Molar concentration of ReO₄ ^-The adsorption efficiency of the biochar selective adsorption solution Re (VII) with the carbon defect site structure is more than 88 percent. Adding 0.008g of bamboo shoot shell biochar material into 100 mL of Cl-containing biochar material^-、NO₂ ^-、NO₃ ^-、SO₄ ^2-、ReO₄ ^-Five-membered ions coexisting in solution and in a molar ratio of m (Cl)^-/NO₂ ^-/NO₃ ^-/SO₄ ^2-/ReO₄ ^-) The adsorption efficiency is only 1.5 percent when the ratio is 300:800:310:0.0350:1 and the bamboo shoot shell biochar selective adsorption solution Re (VII) is used. 0.008g of biochar material with carbon defect site structure is added into 100 mL of biochar material containing Cl^-、NO₂ ^-、NO₃ ^-、SO₄ ^2-、ReO₄ ^-Five-membered ions coexisting in solution and in a molar ratio of m (Cl)^-/NO₂ ^-/NO₃ ^-/SO₄ ^2-/ReO₄ ^-) 300:800:310:0.0350:1, and the adsorption efficiency of the biochar selective adsorption solution Re (VII) with the carbon defect site structure is over 77 percent.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.