阅读说明：本技术 一种从废活性炭中再生金属的方法 (Method for regenerating metal from waste activated carbon ) 是由 郑先强 于 2019-08-23 设计创作，主要内容包括：本发明公开了一种从废活性炭中再生金属的方法,涉及金属回收技术领域,该方法包括：烧结磨粉、二次镍浸出、二次铁浸出、一次镉浸出等步骤,再通过多次压滤处理,能从废活性炭中提取所有有用金属,提高了回收率。(The invention discloses a method for regenerating metal from waste activated carbon, which relates to the technical field of metal recovery, and comprises the following steps: sintering and milling, secondary nickel leaching, secondary iron leaching, primary cadmium leaching and the like, and then performing multiple pressure filtration treatment, so that all useful metals can be extracted from the waste activated carbon, and the recovery rate is improved.)

1. A method for regenerating metals from spent activated carbon, comprising the steps of:

s1, crushing the waste activated carbon into powder, and mixing the powder with the following raw materials: glucose: baking soda: silicon dioxide: the mass portion of the sodium carbonate is 60: 5: (0.1-0.3): 5: 2 to obtain a waste activated carbon mixture;

s2, fully combusting the waste activated carbon mixture by spontaneous combustion under the oxygen-rich condition, and sintering into a block body with a porous structure; collecting smoke dust generated in the combustion process, recovering metals in the dust, and discharging the waste gas after harmless treatment;

s3, grinding the block body with the porous structure in a grinding machine to obtain solid particles with the particle size smaller than 320 meshes;

s4, adding anhydrous sodium sulfate and hydrogen peroxide into the solid particles, mixing and stirring, then adding concentrated sulfuric acid under continuous steam heating and stirring to enable the pH value of the solution to be about 2, and leaching a first precipitate containing nickel and cobalt; then, performing filter pressing treatment to obtain first filter residue containing nickel and cobalt and first mixed filtrate;

s5, adding hydrogen peroxide and lime milk into the first mixed filtrate under continuous steam heating and stirring to enable the pH value of the solution to be about 4, and leaching a second precipitate containing ferric ions, aluminum and chromium; then, performing filter pressing treatment to obtain a second filter residue containing ferric ions, aluminum and chromium and a second mixed solution;

s6, adding hydrogen peroxide and lime milk into the second mixed filtrate under continuous steam heating and stirring to enable the pH value of the solution to be about 5.5, and leaching a third precipitate containing ferric ions, aluminum and chromium for the second time; then, filter pressing treatment is adopted to obtain third filter residue containing ferric ions, aluminum and chromium and a third mixed solution;

s7, adding liquid caustic soda into the third mixed solution to enable the pH value of the solution to be about 8, and leaching out a fourth precipitate containing nickel for the second time; then, filter pressing treatment is adopted to obtain a fourth filter residue containing nickel and a fourth mixed solution;

s8, adding sodium sulfide and sodium hydroxide into the fourth mixed solution to enable the pH value of the solution to be about 9, and leaching a fifth precipitate containing cadmium; then, performing filter pressing treatment to obtain fifth filter residue containing cadmium and a fifth mixed solution; and returning the fifth mixed solution to the solid particles for continuous circulation.

2. A method for regenerating metals from spent activated carbon as claimed in claim 1 wherein the steam heating temperature is 50-70 ℃.

3. A method for regenerating metals from spent activated carbon as in claim 1 or 2, characterized by the fact that the stirring rate is 200- "300 rad/min.

Technical Field

The invention relates to the technical field of metal recovery, in particular to a method for regenerating metal from waste activated carbon.

Background

In recent years, heavy metal pollution events occur frequently in China, so that serious threats are caused to drinking water safety and food safety in China, and the health of human beings is harmed. Some metals, such as cadmium, nickel, ferric ion, aluminum, cobalt, chromium, etc., can cause harm to the human body in trace amounts.

Therefore, heavy metal removal is required before sewage discharge, and the traditional heavy metal removal process is suitable for removing heavy metal ions with higher concentration, and is suitable for removing technologies with low concentration, such as a reverse osmosis method and the like, which have higher cost. The prior common activated carbon adsorption technology has good removal effect on organic pollutants by activated carbon adsorption, and the surface characteristics of the activated carbon can be changed by modification, so that the adsorption of heavy metals can be improved.

However, metals existing in the waste activated carbon after heavy metal adsorption are also considerable resources, the national requirements for environmental protection are more and more strict in the industrial transformation process, the environmental awareness of people is gradually enhanced, and the development of an energy-saving and environment-friendly method for extracting the regenerated metals from the waste activated carbon is very important.

Disclosure of Invention

Therefore, the embodiment of the invention aims to provide a method for regenerating metals from waste activated carbon, which has the advantages of repeatable resource recovery and high recovery rate.

To this end, the method for regenerating metals from waste activated carbon of the embodiment of the invention comprises the following steps:

s1, crushing the waste activated carbon into powder, and mixing the powder with the following raw materials: glucose: baking soda: silicon dioxide: the mass portion of the sodium carbonate is 60: 5: (0.1-0.3): 5: 2 to obtain a waste activated carbon mixture;

s2, fully combusting the waste activated carbon mixture by spontaneous combustion under the oxygen-rich condition, and sintering into a block body with a porous structure; collecting smoke dust generated in the combustion process, recovering metals in the dust, and discharging the waste gas after harmless treatment;

s3, grinding the block body with the porous structure in a grinding machine to obtain solid particles with the particle size smaller than 320 meshes;

s4, adding anhydrous sodium sulfate and hydrogen peroxide into the solid particles, mixing and stirring, then adding concentrated sulfuric acid under continuous steam heating and stirring to enable the pH value of the solution to be about 2, and leaching a first precipitate containing nickel and cobalt; then, performing filter pressing treatment to obtain first filter residue containing nickel and cobalt and first mixed filtrate;

s5, adding hydrogen peroxide and lime milk into the first mixed filtrate under continuous steam heating and stirring to enable the pH value of the solution to be about 4, and leaching a second precipitate containing ferric ions, aluminum and chromium; then, performing filter pressing treatment to obtain a second filter residue containing ferric ions, aluminum and chromium and a second mixed solution;

s6, adding hydrogen peroxide and lime milk into the second mixed filtrate under continuous steam heating and stirring to enable the pH value of the solution to be about 5.5, and leaching a third precipitate containing ferric ions, aluminum and chromium for the second time; then, filter pressing treatment is adopted to obtain third filter residue containing ferric ions, aluminum and chromium and a third mixed solution;

s7, adding liquid caustic soda into the third mixed solution to enable the pH value of the solution to be about 8, and leaching out a fourth precipitate containing nickel for the second time; then, filter pressing treatment is adopted to obtain a fourth filter residue containing nickel and a fourth mixed solution;

s8, adding sodium sulfide and sodium hydroxide into the fourth mixed solution to enable the pH value of the solution to be about 9, and leaching a fifth precipitate containing cadmium; then, performing filter pressing treatment to obtain fifth filter residue containing cadmium and a fifth mixed solution; and returning the fifth mixed solution to the solid particles for continuous circulation.

Preferably, the steam heating temperature is 50-70 ℃.

Preferably, the stirring rate is 200-300 rad/min.

The technical scheme of the embodiment of the invention has the following advantages:

according to the method for regenerating metal from waste activated carbon provided by the embodiment of the invention, a block body with a porous structure is formed by adding trace sodium bicarbonate when waste activated carbon powder is sintered, so that air can be fully contacted with carbon powder for combustion supporting through porous gaps during combustion, and metal-containing substances are fully separated. Through multiple stages of filter pressing treatment, all useful metals can be extracted from the waste activated carbon, and the recovery rate is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flowchart showing a specific example of a method for regenerating metals from waste activated carbon in the embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In describing the present invention, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises" and/or "comprising," when used in this specification, are intended to specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.