阅读说明：本技术 一种机械物理法处理废线路板制备纯铜粉末的工艺 (process for preparing pure copper powder by treating waste circuit board through mechanical and physical method ) 是由 陈维平 王发展 刘方方 于 2019-08-26 设计创作，主要内容包括：本发明公开了一种机械物理法处理废线路板制备纯铜粉末的工艺,步骤包括：废旧线路板破碎预处理、气流分选、磁选除铁、机械粉碎、筛分、摇床分选、球磨除杂、酸浸除杂、球磨细化、铜粉纯化处理等流程,最后获得纯铜粉末。该工艺具有以下优点：获得的铜粉末可直接应用于粉末冶金,整个工艺产生的少量废液、尾矿易于处理实现金属的全回收；与其他可实现废线路板中有价金属循环再生的方法相比,本工艺不需经过冶金过程,就可实现铜的直接材料化,工艺简单,生产投入小,能耗低,污染小。(the invention discloses a process for preparing pure copper powder by treating a waste circuit board by a mechanical physical method, which comprises the following steps: crushing pretreatment of the waste circuit board, air flow separation, magnetic separation for removing iron, mechanical crushing, screening, table separation, ball milling for removing impurities, acid leaching for removing impurities, ball milling for refining, copper powder purification treatment and the like, and finally obtaining pure copper powder. The process has the following advantages: the obtained copper powder can be directly applied to powder metallurgy, and a small amount of waste liquid and tailings generated in the whole process are easy to treat to realize full recovery of metal; compared with other methods for realizing the recycling of valuable metals in waste circuit boards, the process can realize the direct material preparation of copper without a metallurgical process, and has the advantages of simple process, low production investment, low energy consumption and little pollution.)

1. a process for preparing pure copper powder by treating waste circuit boards by a mechanical physical method is characterized by comprising the following steps:

(1) crushing the waste circuit boards, and then carrying out primary physical sorting to obtain a metal concentrate;

(2) Carrying out magnetic separation on the metal concentrate obtained in the step (1), and separating ferromagnetic metal to obtain a non-ferrous metal concentrate;

(3) Further crushing the non-ferrous metal concentrate obtained in the step (2), and screening by using a screen to obtain a material with a size larger than 200 meshes;

(4) Sorting the materials with the particle size larger than 200 meshes obtained in the step (3) by adopting a table concentrator to remove nonmetal, and improving the content of metal in the metal concentrate;

(5) performing ball milling treatment on the metal concentrate obtained in the step (4), grinding residual nonmetal and part of tin-lead solder, and screening to remove the residual nonmetal and part of tin-lead solder, so as to further improve the content of copper in the metal concentrate and obtain a copper concentrate;

(6) Leaching the copper-enriched body obtained in the step (5) by using a leaching agent, removing impurity metals of tin, lead and iron, and carrying out solid-liquid separation to obtain pure copper coarse powder;

(7) refining the pure copper coarse powder obtained in the step (6) by using a high-energy ball mill to obtain copper fine powder;

(8) And (4) reducing the copper fine powder obtained in the step (7) to obtain pure copper powder which can be directly used for powder metallurgy.

2. The process for preparing pure copper powder by treating waste circuit boards by the mechanical physical method according to claim 1, wherein in the step (1), the waste circuit boards are crushed to be less than 5mm by a crusher, and the physical separation is airflow separation.

3. The process for preparing pure copper powder by treating waste circuit boards by the mechanical and physical method according to claim 1, wherein in the step (3), the nonferrous metal concentrate obtained in the step (2) is crushed to less than 0.5mm by a hammer mill.

4. The process for preparing pure copper powder by treating waste circuit boards by the mechanical and physical method according to claim 1, wherein in the step (5), a planetary ball mill is adopted for ball milling in a wet milling mode, a ball milling solvent is water or cyclohexane, the mass ratio of the volume of the water or cyclohexane to the metal concentrate is 0.2-1 ml/g, the ball milling rotation speed is 300-500 r/min, the ball milling time is 2-10 h, and the mass ratio of ball materials is 15: 1-100: 1.

5. the process for preparing pure copper powder by treating waste circuit boards by the mechanical and physical method according to claim 1, wherein in the step (6), the leaching agent is concentrated hydrochloric acid, the concentration of the concentrated hydrochloric acid is 6-10 mol/L, the leaching temperature is 30-110 ℃, the leaching time is 0.5-3 h, and the addition amount of the leaching agent relative to the copper concentrate is 1-3 ml/g.

6. the process for preparing pure copper powder by treating waste circuit boards by the mechanical and physical method according to claim 1, wherein in the step (7), a planetary high-energy ball mill is adopted for high-energy ball milling, the ball milling rotation speed is 300-500 r/min, the ball milling time is 6-20 h, the ball-material mass ratio is 15: 1-100: 1, the process control agent is water or cyclohexane, and the volume of the process control agent and the mass ratio of the pure copper coarse powder are 0.2-2 ml/g.

7. The process for preparing pure copper powder by treating waste circuit boards by the mechanical physical method according to claim 1, wherein stainless steel grinding balls are adopted in the high-energy ball milling in the step (7), Fe pollution exists in the copper fine powder after ball milling, dilute acid is used for leaching and deironing, the concentration of the dilute acid is 1-3 mol/L, and the pure copper fine powder is obtained after solid-liquid separation.

8. the process for preparing pure copper powder by treating waste circuit boards by the mechanical physical method according to claim 5, wherein the main reaction generated in the process of leaching with concentrated hydrochloric acid is as follows:

2HCl+Fe→FeCl₂+H₂↑ (3)

9. The process for preparing pure copper powder by treating waste circuit boards according to claim 7 by using a mechanical physical method, wherein the dilute acid is hydrochloric acid.

10. The process for preparing pure copper powder by treating waste circuit boards by the mechanical and physical method according to claim 1, wherein the copper fine powder is reduced in the hydrogen atmosphere in the step (7).

Technical Field

the invention relates to the technical field of resource recovery of electronic wastes, in particular to a process for preparing pure copper powder by treating waste circuit boards by a mechanical and physical method.

Background

The circuit board is a core component of an electronic product and generally consists of three parts, namely a conductive material, a reinforcing material, an adhesive and the like. The resource of the waste circuit board is mainly embodied in that the waste circuit board contains a large amount of valuable metals, and the content of different circuit boards is different and is mostly between 10 wt.% and 40 wt.%. For example, the copper content of a circuit board in a computer reaches 26.6 wt.%, and the circuit board also contains valuable metals such as tin, lead, aluminum and the like and precious metals such as gold, silver, palladium and the like, so that the recovery value is very high. The recovery of the circuit board has high economic benefit and huge ecological benefit, and toxic and harmful substances such as lead, chromium, mercury, brominated flame retardants and the like contained in the waste circuit board can seriously break the surrounding ecological environment and threaten the human health if not properly treated. The resource treatment of waste circuit boards is an important issue.

at present, the main process of metal recovery in waste circuit boards is as follows: pretreating by a mechanical physical method to obtain a metal concentrate, and then performing pyrometallurgy, hydrometallurgy or biological metallurgy and the like to realize metal regeneration. The process flow is long, the energy consumption is high, and the environmental pollution is large.

Patent CN101049955A discloses a treatment process of waste circuit boards, comprising the following steps: pretreating the waste circuit board to realize the dissociation of metal and nonmetal, obtaining 30-60 meshes of metal powder through physical separation, adding the metal powder into dilute sulfuric acid, blowing air for leaching, filtering, evaporating and crystallizing to obtain blue vitriod. The metal powder also contains metals such as iron, tin and the like, and the metals and the dilute sulfuric acid react and enter the leaching solution, so that the process is difficult to obtain a particularly pure product.

patent CN106381391A discloses a waste circuit board treatment method, which comprises the following steps: the waste circuit board is pretreated to obtain metal concentrate powder, alkaline pressure oxidation leaching and filtering are carried out to obtain leaching liquid and leaching slag, the leaching slag is separated by a table concentrator to obtain copper concentrate, and the copper concentrate is reduced and smelted in a smelting furnace to obtain blister copper. The method has the disadvantages of complex process, expensive required equipment, large amount of smelting tailings and difficult treatment.

Patent CN102671916A discloses a waste circuit board treatment and recovery process, which comprises the following steps: the method comprises the processes of waste cutting, manual sorting, gold removing, tin removing, primary crushing, magnetic separation, secondary crushing, vibration sorting, airflow sorting, granulation crushing, specific gravity sorting, plastic-wood compounding and the like, and can realize the primary recovery of metals and nonmetals.

disclosure of Invention

The invention aims to provide a recycling process which avoids the short flow, low energy consumption and small pollution of the traditional metallurgy process and realizes the efficient recycling of waste metal copper resources aiming at the defects of the existing waste circuit board recycling technology.

The object of the invention is achieved by at least one of the following solutions.

The invention provides a process for preparing pure copper powder by treating a waste circuit board by a mechanical physical method, which comprises the following steps:

(1) crushing the waste circuit boards, and then carrying out primary physical sorting to obtain a metal concentrate;

(2) carrying out magnetic separation on the metal concentrate obtained in the step (1), and separating ferromagnetic metal to obtain a non-ferrous metal concentrate;

(3) further crushing the non-ferrous metal concentrate obtained in the step (2), and screening by using a screen to obtain a material with a size larger than 200 meshes;

(4) Sorting the materials with the particle size larger than 200 meshes obtained in the step (3) by adopting a table concentrator to remove nonmetal, and improving the content of metal in the metal concentrate;

(5) performing ball milling treatment on the metal concentrate obtained in the step (4), grinding residual nonmetal and part of tin-lead solder, and screening to remove the residual nonmetal and part of tin-lead solder, so as to further improve the content of copper in the metal concentrate and obtain a copper concentrate;

(6) Leaching the copper-enriched body obtained in the step (5) by using a leaching agent, removing impurity metals of tin, lead and iron, and carrying out solid-liquid separation to obtain pure copper coarse powder;

(7) Refining the pure copper coarse powder obtained in the step (6) by using a high-energy ball mill to obtain copper fine powder;

(8) and (4) reducing the copper fine powder obtained in the step (7) to obtain pure copper powder which can be directly used for powder metallurgy.

Preferably, in the step (1), the waste circuit boards are crushed by a crusher to be less than 5mm, and the physical sorting is airflow sorting.

preferably, in the step (3), the non-ferrous metal concentrate obtained in the step (2) is pulverized to less than 0.5mm by a hammer mill.

Preferably, in the step (5), a planetary ball mill is adopted for ball milling, the ball milling is carried out in a wet milling mode, a ball milling solvent is water or cyclohexane, the mass ratio of the volume of the water or cyclohexane to the metal concentrate is 0.2-1 ml/g, the ball milling rotation speed is 300-500 r/min, the ball milling time is 3-10 h, and the ball material mass ratio is 15: 1-100: 1.

Preferably, in the step (6), the leaching agent is concentrated hydrochloric acid, the concentration of the concentrated hydrochloric acid is 6-10 mol/L, the leaching temperature is 30-110 ℃, the leaching time is 0.5-3 h, and the addition amount of the leaching agent relative to the copper concentrate is 1-3 ml/g.

Preferably, in the step (7), a planetary high-energy ball mill is adopted for high-energy ball milling, the ball milling rotation speed is 300-500 r/min, the ball milling time is 6-20 h, the ball material mass ratio is 15: 1-100: 1, the process control agent is water or cyclohexane, and the mass ratio of the volume of the process control agent to the pure copper coarse powder is 0.2-2 ml/g.

preferably, stainless steel grinding balls are adopted in the high-energy ball milling in the step (7), Fe pollution exists in the copper fine powder after ball milling, dilute acid is used for leaching and removing iron, the concentration of the dilute acid is 1-3 mol/L, and the pure copper fine powder is obtained after solid-liquid separation.

Preferably, the main reactions occurring during leaching with concentrated hydrochloric acid are:

2HCl+Fe→FeCl₂+H₂↑ (3)

preferably, the dilute acid is hydrochloric acid.

preferably, the copper fine powder in step (7) is reduced in a hydrogen atmosphere.

Compared with the prior art, the invention has the following beneficial effects and advantages:

the recovery treatment process of the waste circuit board provided by the invention mainly adopts a mechanical physical method, avoids a metallurgical process, has the characteristics of short flow, low energy consumption and small pollution, can obtain pure copper powder for powder metallurgy, and realizes direct material application of metal copper. A small amount of tailings generated in the process can enter a metallurgical process for further recovery, so that the full recovery of metals is realized.

Drawings

FIG. 1 is a process flow chart of preparing pure copper powder by treating waste circuit boards by a mechanical and physical method according to an embodiment.

Detailed Description

In order to facilitate an understanding of the invention, reference will now be made to the appended drawings, which together with the description serve to explain the principles of the invention. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.