阅读说明：本技术 采用高效脱Sn药剂从废旧电路板中回收金属Sn的方法 (Method for recovering metal Sn from waste circuit board by adopting efficient Sn-removing agent ) 是由 张修超 张世镖 郝福来 王秀美 李健 赵国惠 逄文好 马东梅 于 2020-12-23 设计创作，主要内容包括：本发明涉及一种采用高效脱Sn药剂从废旧电路板中回收金属Sn的方法,属于废弃资源回收利用领域。包括：电路板预处理,金属Sn的浸出,金属Sn的回收,使用该回收方法的操作条件为：在一定搅拌条件下,pH值为1.0-2.0,液固比为5:1,温度为常温,浸出时间为8-10h。本发明优点是在对电路板中的金属Sn进行高效浸出的同时,也为后续其余稀贵金属的浸出提供便利条件,实现了电路板中金属Sn的梯级浸出与高效回收。Sn的回收率与纯度均较高,无需低温熔炼,能耗较低,回收成本相对少,具有药剂配方简单,工艺流程短,操作方便等优点。非常便于企业规模化生产,具有较好的应用前景,在形成产业化回收后,可取得较好的经济效益与社会效益。(The invention relates to a method for recovering metal Sn from a waste circuit board by adopting an efficient Sn removing medicament, belonging to the field of waste resource recycling. The method comprises the following steps: the method comprises the following steps of pretreatment of a circuit board, leaching of metal Sn, and recovery of the metal Sn, wherein the operating conditions of the recovery method are as follows: under a certain stirring condition, the pH value is 1.0-2.0, the liquid-solid ratio is 5:1, the temperature is normal temperature, and the leaching time is 8-10 h. The invention has the advantages that the invention provides convenient conditions for leaching the rest rare noble metals in the follow-up process while efficiently leaching the metal Sn in the circuit board, and realizes the step leaching and the efficient recovery of the metal Sn in the circuit board. The recovery rate and the purity of Sn are high, low-temperature smelting is not needed, the energy consumption is low, the recovery cost is relatively low, and the method has the advantages of simple medicament formula, short process flow, convenience in operation and the like. The method is very convenient for large-scale production of enterprises, has better application prospect, and can obtain better economic benefit and social benefit after industrialized recovery is formed.)

1. A method for recovering metal Sn from waste circuit boards by adopting an efficient Sn removing agent is characterized by comprising the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; and (3) leading the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board.

2. The method for recovering the metal Sn from the waste circuit board by adopting the high-efficiency Sn removing medicament as claimed in claim 1, wherein: the high-efficiency Sn removing agent is Fe³⁺The solution is at least one of ferric chloride, ferric sulfate and ferric nitrate ferric salt, wherein Fe³⁺The concentration is 25-35 g/L.

3. The method for recovering the metal Sn from the waste circuit board by adopting the high-efficiency Sn removing medicament as claimed in claim 1, wherein: the auxiliary reagent in the high-efficiency Sn removing medicament is H₂SO₄The solution and the HAc-NaAc solution are used for adjusting and stabilizing the pH value required by the solution of the detn agent.

4. The method for recovering the metal Sn from the waste circuit board by adopting the high-efficiency Sn removing medicament as claimed in claim 1, wherein: in the step (1), the waste circuit board is crushed into particles with the size of (5-10 cm) x (5-10 cm).

5. The method for recovering the metal Sn from the waste circuit board by adopting the high-efficiency Sn removing medicament as claimed in claim 1, wherein: in the step (2), the leaching is carried out under the condition of stirring, the liquid-solid ratio is 5:1, the pH value is 1.0-2.0, and the leaching time is 8-10h at normal temperature.

Technical Field

The invention belongs to the field of waste resource utilization and environmental protection, and particularly relates to a method for recovering metal Sn from a waste circuit board by adopting an efficient Sn removing agent.

Background

With the rapid development of the information industry along with the advancement of science and technology, electronic products are more and more applied in the production and life of people, and the frequency of replacement and updating is faster and faster. The circuit board (PCB) is used as the most basic common component of various electrical and electronic product systems, and has rapidly become the main source of electronic garbage in the present times. The waste circuit board contains a plurality of substances harmful to the environment and various valuable rare and precious metals due to complex components. If the waste water cannot be effectively treated and recycled, the waste water is a serious waste of limited resources and also a serious pollution to the environment. In summary, both for recycling resources and for preventing environmental pollution, the rare and precious metals in the circuit board should be effectively recycled.

In the process of recycling waste circuit boards, the metal Sn is not thoroughly treated due to the existence of a large amount of soldering tin and the complex material of the circuit boards, so that Sn is doped in the subsequently leached materials, and finally, the metal Sn and other rare and precious metals are not thoroughly leached and the purity is reduced. At present, the conventional leaching methods are low-temperature smelting, heating, electrolytic Sn removal and wet leaching. The melting and Sn removal are performed for 1.0-3.5h at the temperature of 350-550 ℃, the operation environment is severe, and secondary pollution is caused to the environment. The defects of heating and electrolytic Sn removal are high energy consumption and high recovery cost. When wet leaching is adopted, Sn is unfavorable for leaching other rare and precious metals due to the special existence of Sn, and the step separation leaching of the rare and precious metals cannot be well realized, so that the recovery of Sn and other metals is incomplete.

Therefore, how to effectively treat and efficiently recover the Sn in the waste circuit board provides convenience for the subsequent recovery of the rest rare and precious metals becomes a problem to be solved urgently.

Disclosure of Invention

The invention provides a method for recovering metal Sn from a waste circuit board by adopting an efficient Sn removing agent, which aims to solve the problem that the prior art is easy to cause environmental pollution in the recovery process.

The technical scheme adopted by the invention is as follows: comprises the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; and (3) leading the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board.

The efficient Sn removal agent is Fe³⁺The solution is at least one of ferric chloride, ferric sulfate and ferric nitrate ferric salt, wherein Fe³⁺The concentration is 25-35 g/L.

The auxiliary reagent in the high-efficiency Sn removal medicament is H₂SO₄The solution and the HAc-NaAc solution are used for adjusting and stabilizing the pH value required by the solution of the detn agent.

In the step (1), the waste circuit board is crushed into particles with the size of (5-10 cm) x (5-10 cm).

In the step (2), the leaching is carried out under the condition of stirring, the liquid-solid ratio is 5:1, the pH value is 1.0-2.0, and the leaching time is 8-10h at normal temperature.

The method has the advantages that when the metal Sn is recovered from the waste circuit board, the metal Sn in the circuit board is removed more thoroughly, the recovery rate and the purity of the metal Sn are higher, the circuit board after being subjected to Sn removal enters the next rare and noble metal recovery process, the subsequent leaching and recovery of other rare and noble metals are facilitated, the basic requirements of resource recycling can be met, the recovery rate and the purity of the Sn are higher, the method has better industrial application prospects, and better economic benefits and social benefits can be obtained when large-scale industrial production is carried out.

Drawings

FIG. 1 is an SEM image of the present invention for recovering metallic Sn from a circuit board;

FIG. 2 is a SEM-EDS diagram of the recovery of metallic Sn from a circuit board according to the present invention.

Detailed Description

Example 1

Comprises the following steps:

(1) preprocessing a circuit board: the method comprises the following steps of splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles, wherein the crushing granularity is as follows: 5cm × 5 cm;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; enabling the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next step extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board;

the high-efficiency Sn removal medicament, the liquid-solid ratio, the pH value and the leaching time are as follows:

the result shows that the metallic Sn in the waste circuit board is leached more thoroughly, the soldering tin in the circuit board can be completely removed, the Sn is separated, leached and recovered in a gradient manner, the metallic Sn has higher leaching rate and recovery rate, the leaching rate is 98 percent, the recovery rate is 95 percent, and meanwhile, through analysis and test, the metallic Sn also has higher purity, more than 99.9 percent, and reaches the standard of being sold in the market. After the metal Sn in the circuit board is leached more thoroughly, the metal with low melting point does not influence the cracking and separation of subsequent plastics, can provide convenient conditions for the leaching and recovery of the rest of subsequent rare and precious metals, and is beneficial to resource recovery.

Example 2

Comprises the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles with the crushing particle size of 8cm multiplied by 8 cm;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; enabling the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next step extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board;

the high-efficiency Sn removal medicament, the liquid-solid ratio, the pH value and the leaching time are as follows:

example 3

Comprises the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles; the crushing particle size is 10cm multiplied by 10 cm;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; and (3) leading the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board.

The high-efficiency Sn removal medicament, the liquid-solid ratio, the pH value and the leaching time are as follows:

example 4

Comprises the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles; the crushing particle size is 5cm multiplied by 8 cm;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; and (3) leading the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board.

The high-efficiency Sn removal medicament, the liquid-solid ratio, the pH value and the leaching time are as follows:

example 5

Comprises the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles with the crushing granularity of 5cm multiplied by 10 cm;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; and (3) leading the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board.

The high-efficiency Sn removal medicament, the liquid-solid ratio, the pH value and the leaching time are as follows:

example 6

Comprises the following steps:

(1) preprocessing a circuit board: splitting and sorting the waste circuit boards, shearing and crushing the circuit boards to obtain required circuit board particles with the crushing particle size of 8cm multiplied by 10 cm;

(2) and (3) Sn leaching: placing the circuit board particles into a stirring container at normal temperature and normal pressure, and leaching by adopting an efficient Sn removing agent under certain liquid-solid ratio, pH value and stirring conditions;

(3) and (3) recovering Sn: filtering the mixed solution obtained in the step (2), evaporating and concentrating the filtrate to obtain mixed crystals containing Sn; and (3) leading the mixed crystals to enter the next step for recovering and extracting the metal Sn, returning the evaporation mother liquor to the previous leaching process, taking the filter residue as the next extraction raw material to enter other subsequent processes, and continuing leaching and recovering the rest rare and noble metals, thereby realizing the step separation leaching and recovery of the metal Sn and other rare and noble metals in the waste circuit board.

The high-efficiency Sn removal medicament, the liquid-solid ratio, the pH value and the leaching time are as follows:

it can be seen from the above embodiments that, when the Sn removing agent is used to treat the metal Sn in the waste circuit board, the leaching rate and recovery rate of Sn are high, so that the soldering tin in the circuit board can be completely removed, and the step separation, leaching and recovery of the metal Sn and other rare and noble metals in the circuit board are really realized, so that the metal with low melting point does not affect the cracking and separation of subsequent plastics, and simultaneously, a convenient condition is provided for the subsequent leaching of other rare and noble metals. The method has the advantages of no need of low-temperature smelting, low energy consumption, relatively low recovery cost, simple medicament formula, short process flow, convenient operation, contribution to realizing industrialization and the like. Can meet the basic requirements of resource recycling, has better industrial application prospect, and can obtain better economic benefit and social benefit when carrying out large-scale industrial production.