CN111170277B - Method for recovering bromine in electronic waste smelting smoke dust by wet alkaline system - Google Patents
Method for recovering bromine in electronic waste smelting smoke dust by wet alkaline system Download PDFInfo
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- CN111170277B CN111170277B CN201811339834.XA CN201811339834A CN111170277B CN 111170277 B CN111170277 B CN 111170277B CN 201811339834 A CN201811339834 A CN 201811339834A CN 111170277 B CN111170277 B CN 111170277B
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- smoke dust
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B7/00—Halogens; Halogen acids
- C01B7/09—Bromine; Hydrogen bromide
- C01B7/096—Bromine
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention discloses a method for recovering bromine in electronic waste smelting smoke dust by a wet alkaline system, which comprises the following steps: carrying out dry ball milling on the electronic waste smelting smoke dust to obtain ball milling smoke dust; leaching the ball-milling smoke dust by using 1-5mol/L alkali liquor according to a liquid-solid ratio of 1:1-4 so as to obtain a leaching solution; and carrying out liquid-solid separation on the leachate, and carrying out evaporative crystallization on the obtained leachate to obtain bromine salt or finely extracting bromine to obtain a liquid bromine product. The method has the advantages of high recovery efficiency, low cost, short flow and the like.
Description
Technical Field
The invention belongs to the field of electronic waste smelting smoke dust treatment, and particularly relates to a method for recovering bromine in electronic waste smelting smoke dust by a wet alkaline system.
Background
The comprehensive utilization of the electronic waste has both environmental protection benefit and economic benefit, and the recycling, disassembling and processing system of the electronic waste in China is gradually improved. The electronic waste treatment by the pyrogenic process has the advantages of high efficiency, good benefit and the like, and is widely concerned and popularized.
The electronic waste material simultaneously contains valuable metal components such as copper, lead, zinc, tin, gold, silver and the like, and also contains organic components such as a flame retardant, plastics, organic resin and the like. During the pyrogenic process, smelting smoke dust with high metal and high halogen content is generated. The element composition and phase composition of the smoke dust are obviously different from those of the traditional copper smelting smoke dust, the bromine content in the smoke dust reaches 5-35%, and the smoke dust has great recovery value. However, the technical research on the treatment and recovery of electronic waste smelting smoke dust is not seen at present in China, and international related enterprises also carry out technical blockade on China.
For the recycling of bromine, published literature focuses mainly on the treatment of bromine-containing solutions and bromine-containing plastics. For example, the invention patent of a harmless debromination method of plastic waste containing bromine (CN104722555.A) uses 25% ammonia water to debrominate under the conditions of more than 9.85MPa and more than 300 ℃, and then prepares an ammonium bromide product; the invention patent of sodium bromide preparation method (CN106185995.A) adopts acidification oxidation and air stripping method to prepare bromine-containing gas; a process for extracting bromine from the solution containing bromine (CN105712298. A) includes acidifying, oxidizing and extracting to obtain bromine. The raw materials processed by the technology have single component, long process flow, large pollution, high equipment requirement and high cost.
The electronic waste smelting smoke dust contains 5-35% of bromine, and the recovery and extraction for preparing the bromine salt or the elemental bromine have great benefit. However, bromine in the smoke dust is combined with metal elements such as copper, lead, zinc, tin, gold, silver and the like to exist in the form of compounds, and the conventional process is difficult to efficiently and greenly treat the materials.
Therefore, the existing method for recovering and extracting the bromine from the electronic waste smelting smoke is still to be further improved.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention aims to provide a method for recovering electronic waste smelting smoke dust bromine by a wet method alkaline system with high efficiency, low cost and short process.
According to one aspect of the invention, the invention provides a method for recovering bromine in electronic waste smelting smoke by a wet alkaline system, which comprises the following steps:
carrying out dry ball milling on the electronic waste smelting smoke dust to obtain ball milling smoke dust;
leaching the ball-milling smoke dust by using 1-5mol/L alkali liquor according to the liquid-solid ratio of 1:1-4 so as to obtain a leaching solution;
carrying out liquid-solid separation on the leaching slurry so as to obtain a leaching solution;
and (3) evaporating and crystallizing the leachate to obtain bromine salt, or refining the leachate to extract bromine to obtain a bromine liquid product.
Therefore, the method for recovering bromine in the electronic waste smelting smoke by the wet alkaline system in the embodiment of the invention comprises the steps of sequentially carrying out dry ball milling, leaching treatment and evaporative crystallization on the electronic waste smelting smoke. The inventor finds that the leaching rate and leaching efficiency of bromine can be remarkably improved by carrying out dry ball milling on the electronic waste smelting smoke dust in advance before leaching treatment. Therefore, the method for recovering bromine in electronic waste smelting smoke by using the wet alkaline system in the embodiment of the invention has the advantages of high bromine recovery rate, short flow, high efficiency, low cost and the like.
In addition, the method for recovering bromine in electronic waste smelting smoke by using the wet method alkaline system according to the embodiment of the invention can also have the following additional technical characteristics:
in some embodiments of the invention, the dry ball milling uses a ball to material mass ratio of 1 to 5:1.
In some embodiments of the invention, the dry ball milling is performed at a rotational speed of 300 to 1000r/min.
In some embodiments of the invention, the dry ball milling time is 10 to 60 minutes.
In some embodiments of the present invention, the alkali solution is at least one selected from the group consisting of ammonia, sodium carbonate, sodium hydroxide, and lime.
In some embodiments of the invention, the temperature of the leaching process is 0-100 degrees celsius.
In some embodiments of the invention, the time of the leaching treatment is 30 to 480 minutes;
in some embodiments of the invention, the evaporative crystallization is performed using a double effect evaporator.
In some embodiments of the invention, the refined extraction of bromine uses a liquid chlorine process to produce liquid bromine.
Drawings
FIG. 1 is a flow diagram of a method for recovering bromine from electronic scrap smelting fumes with a wet alkaline system in accordance with one embodiment of the present invention.
FIG. 2 is a flow diagram of a method for recovering bromine from electronic scrap smelting fumes with a wet alkaline system in accordance with one embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
According to one aspect of the invention, the invention provides a method for recovering bromine in electronic waste smelting smoke dust by using a wet alkaline system. The method for recovering bromine from electronic scrap smelting fumes by using the wet alkaline system according to the embodiment of the present invention will be described in detail with reference to fig. 1-2.
S100: dry ball milling
According to the specific embodiment of the invention, firstly, the electronic waste smelting smoke dust is subjected to dry ball milling so as to obtain ball milling smoke dust. The inventor finds that the leaching rate and the recovery rate of the subsequent bromine can be effectively improved by carrying out dry ball milling on the electronic waste smelting smoke dust.
According to the specific embodiment of the invention, the mass ratio of the ball material adopted by the dry ball milling of the electronic waste smelting smoke dust is 1-5:1. The inventor finds that if the mass ratio of the ball materials is too large, the ball milling efficiency is low, and the production cost is high; if the mass ratio of the ball material is too small, agglomerated particles are difficult to effectively break, and part of bromine-containing smoke dust is coated, so that the bromine leaching rate is low. According to a specific example of the present invention, the dry ball milling preferably has a ball to mass ratio of 2 to 3:1. The ball-milling smoke dust obtained by ball milling according to the mass ratio of the ball material has the highest bromine leaching efficiency and leaching rate in the subsequent alkali liquor leaching process.
According to a specific embodiment of the invention, the rotation speed of the dry ball milling is 300-1000r/min, for example, 300r/min, 350r/min, 400r/min, 450r/min, 500r/min, 550r/min, 600r/min, 650r/min, 700r/min, 750r/min, 800r/min, 850r/min, 900r/min, 950r/min or 1000r/min. The dry ball milling time is 10 to 60 minutes, and specifically, may be 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, or 60 minutes. The inventor finds that the rotation speed and time of the dry ball milling greatly influence the ball milling effect of the electronic waste smelting smoke dust, and when the ball milling rotation speed and time are adopted, the bromine leaching rate of the subsequent leaching treatment can be further improved, so that the bromine extraction rate is improved. The inventor finds that when the rotating speed of ball milling by a plurality of methods is lower than 300r/min, agglomerated particles are difficult to effectively break, and the bromine leaching rate is low; if the rotating speed is higher than 1000r/min, the ball milling energy consumption is high, and the production cost is increased. Therefore, the bromine leaching is adversely affected by the rotation speed being too high or too low.
According to a specific example of the present invention, it is preferable that the dry ball milling is performed for 10 to 60 minutes at a rotation speed of 450 to 600 r/min. Therefore, when the optimized dry ball milling rotating speed and time are adopted, the subsequent leaching of bromine can be maximized, and the leaching rate of bromine can be further remarkably improved.
In addition, the steps of carrying out dry ball milling on the electronic waste smelting smoke dust in advance before alkaline liquor leaching and achieving unexpected effects are actually obtained based on the unexpected attempts of the inventor. Because the particle size of the electronic scrap smelting fume itself is small, ball milling of the fume is not usually contemplated, and the ball milling step is not added in the existing treatment process. In the research on how to improve bromine leaching, ball milling on electronic waste smelting smoke dust is unexpectedly tried, and the leaching rate of bromine after ball milling is improved by about 20 percent compared with the leaching rate of bromine without ball milling.
S200: leaching treatment
According to the specific embodiment of the invention, secondly, the ball milling smoke dust is leached by alkali liquor with the concentration of 1-5mol/L according to the liquid-solid ratio of 1:1-4 so as to obtain leachate. Obviously, the molar concentration of the lye and the liquid-solid ratio are necessarily important factors influencing bromine leaching. Therefore, the inventor finds that the leaching effect of the ball milling smoke is best when the ball milling smoke is leached by using 1-5mol/L alkali liquor according to the liquid-solid ratio of 1:1-4.
According to an embodiment of the present invention, further, the alkali solution used may be at least one selected from ammonia, sodium carbonate, sodium hydroxide, and lime. Thereby, the leaching efficiency can be further improved. According to a specific embodiment of the present invention, sodium carbonate or sodium hydroxide is preferably used as the alkali solution.
According to the embodiment of the invention, the temperature of the slurry is controlled to be 0-100 ℃ in the leaching treatment process, so that the leaching time can be shortened, and the leaching efficiency can be improved. Specifically, the leaching time can be controlled to be 30 to 480 minutes.
According to the specific example of the invention, the ball milling smoke dust is preferably leached by using 2-5mol/L alkali liquor according to the liquid-solid ratio of 1:2-3 at 30-50 ℃, the leaching rate of bromine is highest, and the leaching time can be shortened to 30-120 minutes. Therefore, the leaching rate of bromine and the leaching efficiency can be remarkably improved by the leaching conditions.
S300: evaporative crystallization
According to a particular embodiment of the invention, finally, the leaching slurry is subjected to a liquid-solid separation so as to obtain a leaching solution; and (3) evaporating and crystallizing the leachate to obtain bromine salt, or refining the leachate to extract bromine to obtain a bromine liquid product.
Specifically, the leachate is evaporated and crystallized by using a double-effect evaporator. Thereby further improving the crystallization yield and the treatment efficiency. The refined bromine extraction can adopt a liquid chlorine method to prepare liquid bromine.
Example 1
(1) Certain electronic waste smelting smoke dust dry basis composition (%): f0.16, cl 7.85, br 9.13, cu 20.81, zn 9.91, pb 8.83 and Sn 2.90.
(2) Carrying out dry ball milling on the smelting smoke dust for 30min according to the ball material mass ratio of 4:1 and the rotating speed of 450 r/min; 2mol/LNH is added 4 OH solution, liquid-solid ratio 3: and excessive air is introduced at the temperature of 1,40 ℃, the reaction is stirred for 100min, and the leaching rate of bromine is 94.1%.
Example 2
(1) Certain electronic waste smelting smoke dust dry basis composition (%): the same as in example 1.
(2) Carrying out dry ball milling on the smelting smoke dust for 30min according to the ball material mass ratio of 3:1 and the rotating speed of 500 r/min; 1mol/LNa is added 2 CO 3 Solution, liquid-solid ratio 3: introducing excessive air at the temperature of 1,40 ℃ and stirring for reaction for 120min, wherein the leaching rate of bromine is 98.1%.
Example 3
(1) Certain electronic waste smelting smoke dust dry basis composition (%): the same as in example 1.
(2) Carrying out dry ball milling on the smelting smoke dust for 10min according to the ball material mass ratio of 4:1 and the rotating speed of 600 r/min; adding 1.0mol/LNaOH solution, wherein the liquid-solid ratio is 4: introducing excessive air at the temperature of 1,40 ℃ and stirring for reaction for 100min, wherein the leaching rate of bromine is 99.1%.
Comparative example 1 (non-ball milled, same leaching conditions as example 1)
(1) Certain electronic waste smelting smoke dust dry basis component (%): the same as in example 1.
(2) Directly adding 2mol/LNH into smelting smoke dust 4 OH solution, liquid-solid ratio 3: and introducing excessive air at the temperature of 1,40 ℃ and stirring for reaction for 100min, wherein the leaching rate of bromine is 84.1%.
Comparative example 2 (ball milling conditions outside the protective range, leaching conditions as in example 1)
(1) Certain electronic waste smelting smoke dust dry basis composition (%): the same as in example 1.
(2) Carrying out dry ball milling on the smelting smoke dust for 10min according to the ball material mass ratio of 4:1 and the rotating speed of 200 r/min; 2mol/LNH is added 4 OH solution, liquid-solid ratio 3: and introducing excessive air at the temperature of 1,40 ℃ and stirring for reaction for 100min, wherein the leaching rate of bromine is 84.8%.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (5)
1. A method for recovering bromine in electronic waste smelting smoke dust by a wet alkaline system is characterized by comprising the following steps:
carrying out dry ball milling on the electronic waste smelting smoke dust to obtain ball milling smoke dust;
leaching the ball-milling smoke dust by using 1-5mol/L alkali liquor according to a liquid-solid ratio of 1:1-4 so as to obtain leaching slurry;
carrying out liquid-solid separation on the leaching slurry so as to obtain a leaching solution;
evaporating and crystallizing the leachate to obtain bromine salt, or refining the leachate to extract bromine to obtain liquid bromine product, wherein the refined bromine extraction adopts a liquid chlorine method to prepare liquid bromine,
the mass ratio of the ball material adopted by the dry ball milling is 1-5:1;
the rotating speed of the dry ball milling is 300-1000r/min;
the dry ball milling time is 10-60 minutes.
2. The method according to claim 1, wherein the alkali is at least one selected from the group consisting of ammonia water, sodium carbonate, and sodium hydroxide.
3. A method as claimed in claim 2, wherein the temperature of the leaching process is 0-100 degrees celsius.
4. A method according to claim 3, wherein the leaching treatment is carried out for a period of 30-480 minutes.
5. The method according to claim 4, wherein the evaporative crystallization is performed using a double effect evaporator.
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| WO2008106346A2 (en) * | 2007-02-28 | 2008-09-04 | Albemarle Corporation | Processes for producing and using bromine products suitable for reducing mercury emissions during coal combustion |
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Address after: 330031 No. 888, Qian Hu Road, Hongjiao Island, Nanchang, Jiangxi. Patentee after: CHINA NERIN ENGINEERING Co.,Ltd. Patentee after: Jiangxi Huagan Ruilin Precious Metal Technology Co.,Ltd. Address before: 330031 No. 888, Qian Hu Road, Hongjiao Island, Nanchang, Jiangxi. Patentee before: CHINA NERIN ENGINEERING Co.,Ltd. Patentee before: JIANGXI NERIN RARE AND PRECIOUS METALS SCIENCE & TECHNOLOGY CO.,LTD. |