阅读说明：本技术 一种从棕刚玉烟尘中高效提取镓的方法 (Method for efficiently extracting gallium from brown corundum smoke dust ) 是由 张菊花 常雨微 张伟 于 2021-09-24 设计创作，主要内容包括：本发明提供一种从棕刚玉烟尘中高效提取镓的方法,包括以下步骤：首先,将棕刚玉烟尘与焙烧添加剂混合,获得混合物；其次,将所述混合物焙烧,获得第一产物；再次,将所述第一产物加入酸性溶液中进行浸泡,获得第二产物；最后,对所述第二产物进行固液分离,获得含有镓的浸出液。与现有技术相比,本发明提供的方法工艺简单、容易操作,原料成本低廉；本发明利用焙烧与酸浸相结合的方式,提供了一种以棕刚玉烟尘为原料,高选择性的提取金属镓的全新的工艺路线。实验数据表明,采取本发明的方法对棕刚玉烟尘中的金属镓进行提取,镓的浸出率最高可达98％以上,并能够将杂质硅的浸出率控制在0.6％以下。(The invention provides a method for efficiently extracting gallium from brown fused alumina smoke dust, which comprises the following steps: firstly, mixing brown corundum smoke dust and a roasting additive to obtain a mixture; secondly, roasting the mixture to obtain a first product; thirdly, adding the first product into an acidic solution for soaking to obtain a second product; and finally, carrying out solid-liquid separation on the second product to obtain a leaching solution containing gallium. Compared with the prior art, the method provided by the invention has the advantages of simple process, easy operation and low cost of raw materials; the invention provides a brand new process route for extracting gallium metal with high selectivity by using brown corundum smoke dust as a raw material by utilizing a mode of combining roasting and acid leaching. Experimental data show that the method provided by the invention is adopted to extract the gallium metal in the brown corundum smoke dust, the leaching rate of the gallium can reach more than 98% at most, and the leaching rate of impurity silicon can be controlled below 0.6%.)

1. A method for efficiently extracting gallium from brown corundum smoke dust comprises the following steps:

s1, mixing the brown corundum smoke dust with a roasting additive to obtain a mixture;

s2, roasting the mixture to obtain a first product;

s3, adding the first product into an acidic solution for soaking to obtain a second product;

s4, carrying out solid-liquid separation on the second product to obtain a leaching solution containing gallium.

2. The method according to claim 1, wherein the mass ratio of the brown corundum smoke dust to the roasting additive in the mixture is 1: (0.5 to 1.3).

3. The method of claim 1, wherein the roasting additive is selected from the group consisting of one or more of calcium carbonate, sodium carbonate, or calcium oxide in combination.

4. The method of claim 1, wherein the temperature of the firing is 750 to 950 ℃.

5. The method according to claim 1, wherein the roasting time is 1-3 hours.

6. The method according to claim 1, wherein the acidic solution is concentrated sulfuric acid with a volume concentration of 10-30%.

7. The method according to claim 1, wherein the soaking temperature is 30-100 ℃ and the soaking time is 1-3 h.

8. The method according to claim 1, wherein the liquid-solid ratio of the acidic solution to the first product is 10-15 mL/g.

9. A method according to claim 1, wherein the brown fused alumina soot comprises, in weight percent: SiO 2₂ 25～40％、K₂O 10～20％、Al₂O₃ 10～20％、SO₃ 2～5％、Fe₂O₃2～5％、SiC 2～5％、MnO 0.3～1.3％、P₂O₅ 0.5～1.2％。

10. The method of claim 9, wherein: in the brown corundum smoke dust, the content of metal gallium is 0.07-0.2% by weight in terms of gallium oxide.

Technical Field

The invention belongs to the technical field of valuable component recovery in brown corundum smoke dust, and particularly relates to a method for efficiently extracting gallium from brown corundum smoke dust.

Background

The brown corundum smoke dust refers to smoke dust discharged in the high-temperature smelting process of an electric arc furnace in the production process of brown corundum. Sources of brown corundum soot include mechanical dust (such as fine coal dust from anthracite, iron oxide powder from iron filings, and mineral material in fragments during bauxite calcination), and also chemical dust generated during high temperature calcination. The amount of brown corundum smoke generated in China every year is up to tens of thousands of tons by calculating according to 3% -5% of dust amount. The emission of high-concentration smoke dust can cause serious harm to the ecological environment, most manufacturers choose to pile or bury corundum smoke dust in places, and the treatment mode can cause pollution to the land.

Gallium contained in brown corundum smoke dust is an important valuable metal and has important application value in the electronic industry and other high-tech fields. If the brown corundum smoke dust can be used for efficiently extracting the gallium element, the method has environmental benefit and economic benefit. The existing methods for extracting gallium from brown corundum smoke mainly comprise two methods:

one is a direct acid leaching method, namely gallium in brown corundum smoke dust is directly leached by adopting acid solutions such as hydrochloric acid, sulfuric acid and the like, and then the gallium is recovered and enriched by adopting an ion exchange or extraction mode. The method has the problems of high filtration difficulty and low gallium extraction rate. The document (Transactions of non-ferrous Metals Society of China, vol.9 of 2018, P1862-1868) mentions a method for leaching gallium in brown corundum smoke dust by using mixed acid formed by hydrofluoric acid and sulfuric acid, so that the extraction efficiency of gallium is improved to a certain extent, but the treatment difficulty of subsequent waste liquid is increased by the residue of a large amount of fluoride ions in the leachate, and the environment is easily damaged.

The other method is to adopt a mode of combining sintering and alkaline leaching, firstly adding a sintering agent into corundum soot, and then preparing gallium through material preparation, roasting, grinding, alkaline leaching, separation, alkaline leaching, electrolysis, refining and purification. Compared with the direct acid leaching method, the method has the advantages that the leaching rate of gallium is improved, but the process route is relatively complex, and two sections of alkaline leaching and electrolytic purification are needed. In addition, the method has a disadvantage that the dissolution rate of impurity silicon is high, and the influence of the impurity silicon still needs to be considered when gallium metal is purified from the leaching solution subsequently, so that the subsequent process treatment is inconvenient.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the method for efficiently extracting gallium from brown fused alumina smoke dust, which has the advantages of high extraction efficiency, good selectivity on impurity silicon, simple process flow and easy operation.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention provides a method for efficiently extracting gallium from brown corundum smoke dust, which comprises the following steps:

s1, mixing the brown corundum smoke dust with a roasting additive to obtain a mixture;

s2, roasting the mixture to obtain a first product;

s3, adding the first product into an acidic solution for soaking to obtain a second product;

s4, carrying out solid-liquid separation on the second product to obtain a leaching solution containing gallium.

On the basis of the technical scheme, the mass ratio of the brown corundum smoke dust to the roasting additive is 1: (0.5 to 1.3).

On the basis of the technical scheme, the roasting additive is selected from one or more of calcium carbonate, sodium carbonate or calcium oxide.

On the basis of the technical scheme, the roasting temperature is 750-950 ℃.

On the basis of the technical scheme, the roasting time is 1-3 h.

On the basis of the technical scheme, the acid solution is concentrated sulfuric acid with the volume concentration of 10-30%.

On the basis of the technical scheme, the soaking temperature is 30-100 ℃, and the soaking time is 1-3 hours.

On the basis of the technical scheme, the liquid-solid ratio of the acidic solution to the first product is 10-15 mL/g.

On the basis of the technical scheme, the brown corundum smoke dust comprises the following main components in percentage by weight: SiO 2₂ 25～40％、K₂O 10～20％、Al₂O₃ 10～20％、SO₃ 2～5％、Fe₂O₃ 2～5％、SiC 2～5％、MnO 0.3～1.3％、P₂O₅ 0.5～1.2％。

On the basis of the technical scheme, the content of metal gallium in the brown fused alumina smoke dust is 0.07-0.2% by weight in terms of gallium oxide.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a brand new process route for extracting gallium metal with high selectivity by using brown corundum smoke dust as a raw material by utilizing a mode of combining roasting and acid leaching. Compared with the prior art, the method provided by the invention has the advantages of simple process, easy operation, low cost of raw materials, more than 90% of gallium leaching rate and more than 98% of optimal conditions; the leaching rate of the impurity silicon is lower than 6 percent, and the leaching rate of the impurity silicon can be controlled below 0.2 percent under the optimal condition.

Drawings

FIG. 1 is a schematic flow chart of the method for efficiently extracting gallium from brown corundum soot provided by the invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be obtained by an existing method.

According to an exemplary embodiment of the present invention, there is provided a method for efficiently extracting gallium from brown corundum soot, comprising the steps of:

s1, mixing the brown corundum smoke dust with a roasting additive to obtain a mixture;

s2, roasting the mixture to obtain a first product;

s3, adding the first product into an acidic solution for soaking to obtain a second product;

s4, carrying out solid-liquid separation on the second product to obtain a leaching solution containing gallium.

In some preferred embodiments, the mass ratio of the brown corundum soot to the roasting additive in the mixture is 1: (0.5 to 1.3). When the addition amount of the roasting additive is lower than the range, the aluminosilicate of the gallate wrapping layer is not completely damaged, so that the leaching rate of gallium is low; when the addition amount of the roasting additive is higher than the range, the leaching rate of gallium cannot be further improved, and resource waste is also caused. More preferably, the mass ratio of the brown corundum smoke dust to the roasting additive is 1: (0.8 to 1.3).

In some preferred embodiments, the roasting additive is selected from the group consisting of one or more of calcium carbonate, sodium carbonate, or calcium oxide in combination.

In some preferred embodiments, the temperature of the firing is 750 to 950 ℃. In the present invention, the choice of the firing temperature also affects the leaching rate of gallium. When the roasting temperature is lower than 750 ℃, the roasting additive and brown corundum smoke dust cannot form sufficient reaction, so that the dissolution rate of gallium is low; when the high roasting temperature is higher than 950 ℃, the liquid sodium salt or calcium salt generated by melting the roasting additive can wrap the gallate, so that the subsequent leaching rate of gallium is reduced.

In some preferred embodiments, the time for the calcination is 1 to 3 hours. More preferably, the calcination time is 2 h.

In some preferred embodiments, the acidic solution is concentrated sulfuric acid with a volume concentration of 10-30%.

In some preferred embodiments, the liquid-to-solid ratio of the acidic solution to the first product is 10 to 15 mL/g.

In some preferred embodiments, in step S3, the soaking time is 1 to 3 hours, and more preferably, the soaking time is 2 to 3 hours. The soaking temperature is 30-100 ℃. More preferably, the soaking temperature is 50-90 ℃, and most preferably, the soaking temperature is 80-90 ℃.

The brown corundum smoke raw material related by the method comprises the following main components in percentage by weight: SiO 2₂25～40％、K₂O 10～20％、Al₂O₃10-20% of SO₃ 2～5％、Fe₂O₃ 2～5％、SiC 2～5％、MnO 0.3～1.3％、P₂O₅0.5 to 1.2 percent. Wherein, the weight percentage of gallium is 0.07-0.20% counted by gallium oxide.

In the brown corundum smoke dust, K and S exist in the form of potassium sulfate, Al exists in the form of corundum and aluminosilicate, Si mainly exists in the form of amorphous silicate, and a small part exists in the form of simple substance and silicon carbonitride. Besides being distributed in the aluminosilicate phase, a part of Ga and potassium are enriched in potassium sulfate, and are mainly in the forms of sodium gallate and potassium gallate.

The method for efficiently extracting gallium from brown corundum soot according to the present invention will be described in detail with reference to examples, comparative examples and experimental data.

The chemical compositions of brown corundum smoke dust samples related to the embodiments and the comparative examples of the invention are shown in the following table 1:

TABLE 1 chemical composition (wt.%) of brown corundum soot samples

	SiO2	K2O	Al2O3	SO3	Fe2O3	SiC	MnO	P2O5	Ga2O3	Others
											Sample 1	27.647	13.871	11.467	3.085	2.837	2.27	0.757	0.712	0.114	37.211
Sample 2	30.159	15.364	12.307	3.117	3.212	1.714	0.535	0.612	0.123	32.857
											Sample 3	25.654	12.259	11.786	2.996	2.565	2.332	0.753	0.645	0.126	40.884

Example 1

The following operations were performed on brown fused alumina soot samples 1-3 in Table 1, respectively:

mixing the brown corundum smoke dust sample with sodium carbonate according to the mass ratio of 1:1, and then putting the mixture into a grinding body to be uniformly ground. And (3) putting a proper amount of ground mixture into a crucible for roasting, setting a muffle furnace program, heating to 850 ℃, keeping the temperature for 2 hours, taking out the crucible after the program cooling is finished, and cooling to room temperature.

Grinding the roasted mixture in a sample grinding machine, putting 10g of ground smoke dust sample in a three-neck flask, adding a sulfuric acid solution with the volume fraction of 25% in a water bath kettle, wherein the solid-to-solid ratio (mL/g) of a leaching solution is 10:1, stirring at the speed of 20rad/min, leaching at 90 ℃ for 3h, taking out a three-neck flask, and performing suction filtration to obtain leaching residues and filtrate.

The leaching rate of metal gallium and impurity silicon is calculated by respectively detecting the concentration of the gallium leaching solution and the concentration of the silicon leaching solution in the obtained filtrate, and the experimental result is shown in the following table 2:

TABLE 2 EXAMPLE 1 gallium and silicon leach rates from brown fused alumina samples 1-3 after treatment

As can be seen from the above table, the method provided in example 1 is used to extract gallium from brown corundum soot samples 1-3, so that the dissolution rate of impurity silicon can be significantly reduced while a higher gallium extraction rate is obtained. The experimental result shows that the leaching rate of gallium is more than 97%, and the leaching rate of impurity silicon is only about 0.5%.

TABLE 3 Experimental parameters and conditions for examples 1-5 and comparative examples 1-6

Examples 2 to 5

The procedure of example 1 was repeated according to the experimental parameters and conditions in table 3, and the brown corundum soot 1 in table 1 was treated separately.

Comparative example 1

Brown corundum soot sample 1 in table 1 was treated as follows:

10g of brown corundum smoke dust is taken and placed in a three-neck flask, sulfuric acid solution with the volume fraction of 25% is added into a water bath kettle, the solid-to-solid ratio (mL/g) of the leaching solution is 10:1, the mixture is stirred at the speed of 20rad/min, the mixture is leached for 3 hours at the temperature of 90 ℃, the three-neck flask is taken out and filtered, and leaching residues and filtrate are obtained.

Comparative example 2

Brown corundum soot sample 1 in table 1 was treated:

mixing the brown corundum smoke dust and sodium carbonate according to the mass ratio of 1:1, and then putting the mixture into a mortar for grinding uniformly. And (3) taking a proper amount of ground mixture, putting the ground mixture into a crucible, setting a muffle furnace program to heat the mixture to 850 ℃, preserving heat for 2 hours, taking out the crucible after the program cooling is finished, and cooling the crucible to room temperature.

And (4) putting the mixture after roasting into a sample grinder for grinding. Putting 10g of ground smoke dust sample into a three-neck flask, adding 25% sodium hydroxide solution into a water bath kettle, stirring at a rotation speed of 20rad/min with a solid-to-solid ratio (mL/g) of a leaching solution of 10:1, leaching for 3 hours at 90 ℃, taking out the three-neck flask, and performing suction filtration to obtain leaching residues and filtrate.

Comparative examples 3 to 6

The procedure of example 1 was repeated according to the experimental parameters and conditions in Table 3, and the brown corundum soot sample 1 in Table 1 was treated separately.

Experimental data

The filtrates obtained in the above examples and comparative examples were subjected to sample analysis, the gallium concentration and the silicon concentration in the leachate were measured, and the leaching rates of gallium and silicon were calculated from the concentration test results, and the results are shown in the following table:

TABLE 4 Leaching rates of gallium and silicon in examples 1-5 and comparative examples 1-6

From the above table, it can be seen that:

the comparative example 1 adopts the direct acid leaching method to extract gallium in brown corundum smoke dust, the leaching rate of the gallium is very low, and the leaching rate of impurity silicon is also higher.

Comparative example 2 adopts a combined technical route of roasting and alkaline leaching, and although the leaching rate of gallium is improved to a certain extent compared with the treatment method of direct acid leaching, the problem of overhigh leaching rate of impurity silicon exists.

The test result of the comparative example 3 shows that when the addition amount of the roasting additive is lower, the equivalent damage to the aluminosilicate of the coating layer of the gallate is incomplete, so the gallium leaching rate is lower; comparative example 4 shows that, with the increase of the addition amount of the roasting additive, although the destructiveness to the coating layer of the aluminosilicate is stronger, so that gallium metal in the subsequent leaching process can be leached into the leaching solution more, and a higher leaching rate is obtained, considering that the excessive addition of the roasting additive can cause resource waste, and the leaching rate is not obviously increased, the comprehensive consideration is that the addition ratio of the roasting additive is not too high, and the mass ratio of brown corundum smoke dust to the roasting additive is controlled to be 1: the most preferable range is (0.5-1.3).

In addition, the test results of comparative examples 5 and 6 show that the calcination temperature is too low or too high, and the extraction of gallium is not facilitated. When the roasting temperature is too low, the roasting additive and the brown corundum smoke do not react sufficiently; when the roasting temperature is too high, especially when sodium carbonate is used as a roasting additive, a liquid sodium salt phase generated by melting the additive is filled in a high-melting-point gap to form a package, so that the subsequent leaching rate is reduced.

The test results of examples 1-5 prove that the roasting temperature and the type of the roasting agent are key factors influencing the leaching effect of gallium. Wherein, the leaching rate of gallium is obviously improved along with the rise of the roasting temperature, and when the roasting temperature is 850 ℃, the extraction rate of gallium can reach more than 98 percent when sodium carbonate is selected as a roasting additive; if calcium carbonate is selected as the roasting additive, the leaching rate of the impurity silicon can be further controlled, and the leaching rate of the impurity silicon can be controlled to be 0.18 percent.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.