A method for recovering germanium and tannin from tannin germanium precipitation residue

Abstract

The invention discloses a method for recovering germanium and tannin from tannin germanium precipitated slag. The method comprises the following steps: slurrying the tannin germanium precipitated slag and sodium hydroxide solution, adding the slurry into a reactor, adding hydrogen peroxide into the reactor for alkaline dissolution and oxidation decomposition, dissolving the tannin and germanium, obtaining a sodium tannate germanium solution, chlorinating and volatilizing the germanium in the sodium tannate germanium solution with industrial concentrated hydrochloric acid to recover the germanium, producing a volatile mother liquor, adding lime into the volatile mother liquor to remove aluminum, silicon and arsenic, introducing oxygen to oxidize and precipitate iron and adsorb and precipitate germanium to obtain a purified mother liquor, and vacuum evaporating and concentrating the purified mother liquor at low temperature to obtain sodium tannate, which is then returned to the tannin germanium precipitation process for use in a germanium-containing wet zinc smelting solution. The method effectively separates impurities such as aluminum and silicon from the tannin germanium precipitated slag, avoids calcination of the tannin germanium precipitated slag, and has no gas pollution caused by combustion of organic matter. Meanwhile, the tannin in the tannin germanium precipitated slag can be recovered and reused.

Description

Technical Field

[0001] The invention relates to a method for recovering germanium and tannin from tannin germanium precipitation slag, belonging to the technical field of hydrometallurgy. Background Art

[0002] As a rare metal, germanium is widely used in high-tech fields. However, there are very few independently exploitable germanium deposits in nature. Instead, it is associated with complex metal sulfide ores, especially sphalerite. In the hydrometallurgical process of sphalerite, in the conventional leaching process of zinc roasted sand, germanium is not leached but enriched in the zinc leaching slag. The recovery of germanium in zinc leaching slag has become the main way to recover germanium.

[0003] Methods for recovering germanium from germanium-containing zinc leaching slag include pyrometallurgical reduction volatilization, wet high-temperature high-acid leaching, and direct oxygen pressure leaching of germanium-containing zinc concentrate. Conventional zinc smelting process and fuming furnace volatilization process of germanium-containing zinc oxide are used, and zinc and germanium are leached from the germanium-containing zinc oxide dust. Liquid sulfur dioxide reduction acid leaching is used to leach the germanium in the zinc leaching slag. The smelting process of leaching zinc leaching slag by sulfur dioxide high-pressure reduction can effectively recover the valuable metals in the zinc leaching slag; direct high-temperature acid leaching process of zinc sulfide concentrate is used to leach the slag while leaching zinc. In general, the recovery of germanium in the zinc smelting process is to dissolve germanium into the wet zinc smelting solution by acid leaching process, and then separate and enrich the germanium in the solution. Among them, the direct high-temperature acid leaching process uses zinc powder neutralization precipitation to separate and enrich germanium, the sulfur dioxide reduction acid leaching process uses lime neutralization precipitation to separate and enrich germanium, and the acid leaching solution of zinc oxide dust uses tannin to precipitate germanium. The zinc powder neutralization method easily produces arsenic in the solution, which requires precise protection; the lime neutralization method produces a large amount of gypsum, and the secondary leaching of gypsum easily causes the loss of germanium; the tannin precipitation germanium consumption is large, and the amount of tannin added is 25 times the amount of germanium or even higher.

[0004] The recovery of germanium in zinc concentrate mainly adopts the process of fuming volatilization of zinc oxide dust-acid leaching-tannin precipitation of germanium. This method has a high germanium recovery efficiency, but it is also easy to volatilize germanium through chlorination. However, due to the large consumption of tannin and the need to use a calcination process to burn and remove organic matter such as tannin from the tannin germanium precipitation residue, it cannot be effectively recovered and reused in a sequential manner, resulting in a high cost for germanium recovery.

[0005] Therefore, realizing the direct recovery of germanium from tannin germanium precipitate slag without calcination and the recycling of tannin is of great significance to reducing costs and eliminating gas pollution caused by the combustion of organic matter. Summary of the invention

[0006] The invention provides a method for recovering germanium and tannin from tannin germanium precipitated slag. The method comprises the following steps: oxidative dissolution with alkali solution, and direct chlorination and volatilization of the germanium-containing solution to separate and recover the germanium. The calcination of the tannin germanium precipitated slag is avoided, and there is no gas pollution caused by the combustion of organic matter. Meanwhile, impurities such as aluminum, silicon, arsenic and iron are effectively separated from the volatile mother liquor, so that the recovery of germanium in the tannin germanium precipitated slag and the recovery and reuse of tannin are realized.

[0007] A method for recovering germanium and tannin from tannin germanium precipitation residue, the specific steps are as follows:

[0008] Tannin germanium precipitation residue obtained by using the traditional tannin germanium precipitation process for germanium-containing wet zinc smelting solution is slurried with sodium hydroxide solution and added to a reactor. Hydrogen peroxide is added to the reactor for alkaline dissolution and oxidation decomposition. After liquid-solid separation, filtrate I and filter residue I are obtained. Filtrate I is a sodium tannate germanium solution. Industrial concentrated hydrochloric acid is added to chlorinate and volatilize the germanium in the sodium tannate germanium solution to recover germanium. After volatilization, a volatile mother liquor is produced. The volatilized mother liquor is stirred and reacted with lime. After liquid-solid separation, filtrate II and filter residue II are obtained. Oxygen is then introduced into filtrate II to oxidize and precipitate iron, and the residual germanium that is not volatilized in filtrate II is adsorbed and precipitated by iron hydroxide. After liquid-solid separation, filter residue III and purified mother liquor are obtained. The purified mother liquor is evaporated and concentrated at low temperature in a vacuum to obtain sodium tannate, which is returned to the tannin germanium precipitation process for germanium-containing wet zinc smelting solution. Filter residue I, filter residue II and filter residue III are sent to wet zinc smelting slag treatment for harmless treatment and germanium pyro-volatilization recovery.

[0009] Furthermore, the mass fraction of germanium in the tannin germanium precipitation residue is 2-10%.

[0010] Furthermore, the concentration of the sodium hydroxide solution is 20-30 g / L.

[0011] Furthermore, the solid-to-liquid ratio of the tannin germanium precipitate residue to the sodium hydroxide solution is 1:4 to 1:6 g / mL.

[0012] Furthermore, the amount of hydrogen peroxide added in the alkali-dissolving oxidation decomposition is 10-15% of the mass of the germanium precipitated slag, and the hydrogen peroxide is a commercially available industrial product with a mass concentration of 30%; the alkali-dissolving oxidation decomposition is stirred and reacted at 80-90° C. for 90-120 minutes.

[0013] Furthermore, the chlorination volatilization recovery of germanium is a traditional hydrochloric acid volatilization recovery process of germanium tetrachloride.

[0014] Furthermore, the lime removal of aluminum, silicon and arsenic is to add lime to adjust the pH of the mother liquor to 4-5, and perform a neutralization precipitation and impurity removal process.

[0015] Furthermore, the oxygen oxidation precipitation of iron and adsorption precipitation of germanium is a known process of hydrolyzing ferric hydroxide to precipitate germanium.

[0016] Furthermore, the low-temperature vacuum evaporation and concentration is a vacuum evaporation and concentration process known in the art carried out at 40-60°C.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention effectively removes impurities such as aluminum and silicon from tannin germanium precipitate slag, and separates the impurities from the germanium.

[0019] (2) The present invention realizes the preparation of germanium tetrachloride by volatilization of tannin germanium precipitate slag without calcination, and there is no gas pollution caused by the combustion of organic matter.

[0020] (3) The present invention realizes the recovery of unreacted excess tannin in the tannin germanium precipitation residue, thereby reducing the tannin consumption of germanium precipitation. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the above contents. The hydrogen peroxide used in the examples is a commercially available industrial product with a mass concentration of 30%.

[0022] Example 1

[0023] The method for recovering germanium and tannin by using tannin germanium precipitation slag obtained by conventional tannin germanium precipitation process in germanium-containing hydrometallurgical zinc solution as raw material, wherein the mass fraction of germanium is 2.15%, has the following specific steps:

[0024] The tannin germanium precipitate residue and the sodium hydroxide solution with a concentration of 20g / L are slurried at a solid-liquid ratio of 1:6g / mL, and added into a reactor, and hydrogen peroxide with a mass percentage of 15% of the tannin germanium precipitate residue is added into the reactor, and stirred for 90 minutes at 80°C to dissolve the tannin and germanium into the solution, and the filtrate I and the filter residue I are obtained after liquid-solid separation. The filtrate I is a sodium tannate germanium solution, and the germanium in the sodium tannate germanium solution is chlorinated and volatilized by using industrial concentrated hydrochloric acid with a concentration of 4mol / L to recover germanium, and a volatile mother liquor is produced. The volatile mother liquor is added with stone The ash is adjusted to pH = 4.22 to remove aluminum, silicon and arsenic. After liquid-solid separation, filtrate II and residue II are obtained. Oxygen is introduced into filtrate II to oxidize and precipitate iron, and ferric hydroxide is used to adsorb and precipitate the non-volatile residual germanium in filtrate II. After liquid-solid separation, residue III and purified mother liquor are obtained. The purified mother liquor is vacuum evaporated and concentrated at 40°C to obtain sodium tannate, which is returned to the tannin germanium precipitation process for germanium-containing wet zinc smelting solution; residue I, residue II and residue III are sent to wet zinc smelting slag treatment for harmless treatment and germanium pyrometallurgical volatilization recovery.

[0025] The germanium recovery rate in this embodiment is 95.12%, and the tannin recovery rate is 73.96%.

[0026] Example 2

[0027] The method for recovering germanium and tannin is based on the tannin germanium precipitated slag obtained by the traditional tannin germanium precipitation process using germanium-containing hydrometallurgical zinc solution as raw material, wherein the mass fraction of germanium is 6.23%. The specific steps are as follows:

[0028] The tannin germanium precipitate residue and the sodium hydroxide solution with a concentration of 30g / L were slurried at a solid-liquid ratio of 1:4g / mL, and added to a reactor. In the reactor, 13% of the mass of the tannin germanium precipitate residue was added with hydrogen peroxide. The mixture was stirred at 85°C for 120 minutes to dissolve the tannin and germanium into the solution. After liquid-solid separation, filtrate I and residue I were obtained. Filtrate I was a sodium tannate germanium solution. The germanium in the sodium tannate germanium solution was chlorinated and volatilized with industrial concentrated hydrochloric acid with a concentration of 5mol / L to recover germanium, and a volatile mother liquor was produced. The volatile mother liquor was added The pH value is adjusted to 4.97 with lime to remove aluminum, silicon and arsenic. After liquid-solid separation, filtrate II and residue II are obtained. Oxygen is introduced into filtrate II to oxidize and precipitate iron, and residual germanium that has not volatilized in filtrate II is adsorbed and precipitated by ferric hydroxide. After liquid-solid separation, residue III and purified mother liquor are obtained. The purified mother liquor is vacuum evaporated and concentrated at 50°C to obtain sodium tannate, which is returned to the tannin germanium precipitation process for germanium-containing wet zinc smelting solution; residue I, residue II and residue III are sent to wet zinc smelting slag treatment for harmless treatment and germanium pyrometallurgical volatilization recovery.

[0029] The germanium recovery rate in this embodiment is 95.73%, and the tannin recovery rate is 70.82%.

[0030] Example 3

[0031] The method for recovering germanium and tannin is based on the tannin germanium precipitated slag obtained by the traditional tannin germanium precipitation process using germanium-containing hydrometallurgical zinc solution as raw material, wherein the mass fraction of germanium is 9.57%, and the specific steps are as follows:

[0032] The tannin germanium precipitate residue and the sodium hydroxide solution with a concentration of 25g / L were slurried at a solid-liquid ratio of 1:5g / mL, and added to a reactor, and hydrogen peroxide with a mass ratio of 10% of the tannin germanium precipitate residue was added to the reactor, and stirred for 100 minutes at 90°C to dissolve the tannin and germanium into the solution. After liquid-solid separation, filtrate I and filter residue I were obtained. Filtrate I was a sodium tannate germanium solution. The germanium in the sodium tannate germanium solution was chlorinated and volatilized with industrial concentrated hydrochloric acid with a concentration of 6mol / L to recover germanium, and a volatile mother liquor was produced. The volatile mother liquor was added The pH value is adjusted to 4.53 with lime to remove aluminum, silicon and arsenic. After liquid-solid separation, filtrate II and residue II are obtained. Oxygen is introduced into filtrate II to oxidize and precipitate iron, and residual germanium that has not volatilized in filtrate II is adsorbed and precipitated by ferric hydroxide. After liquid-solid separation, residue III and purified mother liquor are obtained. The purified mother liquor is vacuum evaporated and concentrated at 60°C to obtain sodium tannate, which is returned to the tannin germanium precipitation process for germanium-containing wet zinc smelting solution; residue I, residue II and residue III are sent to wet zinc smelting slag treatment for harmless treatment and germanium pyrometallurgical volatilization recovery.

[0033] The germanium recovery rate in this embodiment is 95.98%, and the tannin recovery rate is 67.25%.

[0034] The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes made without departing from the spirit of the present invention are also included within the knowledge scope of ordinary technicians in the field.

Claims

1. A method for recovering germanium and tannin from tannin germanium precipitation residue, characterized in that: The specific steps are as follows: The tannin germanium precipitated residue is slurried with sodium hydroxide solution and added to a reactor. Hydrogen peroxide is added to the reactor for alkaline dissolution and oxidation decomposition. After liquid-solid separation, filtrate I and filter residue I are obtained. Filtrate I is a sodium tannate germanium solution. Industrial concentrated hydrochloric acid is added to chlorinate and volatilize the germanium in the sodium tannate germanium solution to recover germanium. After volatilization, a volatile mother liquor is produced. The volatilized mother liquor is stirred and reacted with lime. After liquid-solid separation, filtrate II and filter residue II are obtained. Oxygen is then introduced into filtrate II to oxidize and precipitate iron and adsorb and precipitate the residual germanium that is not volatilized in filtrate II. After liquid-solid separation, filter residue III and purified mother liquor are obtained. The purified mother liquor is vacuum evaporated and concentrated at 40-60° C. to obtain sodium tannate, which is returned to the tannin germanium precipitation process for germanium-containing wet zinc smelting solution. Filter residue I, filter residue II and filter residue III are sent to wet zinc smelting slag treatment for harmless treatment and germanium pyro-volatilization recovery. The amount of hydrogen peroxide added for alkali dissolution oxidation decomposition is 10-15% of the mass of the germanium precipitated slag, and the hydrogen peroxide is a commercially available industrial product with a mass concentration of 30%; The alkaline dissolution oxidation decomposition is carried out by stirring and reacting at 80-90° C. for 90-120 minutes.

2. The method for recovering germanium and tannin from tannin germanium precipitation residue according to claim 1, characterized in that: The mass fraction of germanium in the tannin germanium precipitation slag is 2-10%.

3. The method for recovering germanium and tannin from tannin germanium precipitation residue according to claim 1, characterized in that: The concentration of the sodium hydroxide solution is 20-30 g / L.

4. The method for recovering germanium and tannin from tannin germanium precipitation residue according to claim 1, characterized in that: The solid-to-liquid ratio of the tannin germanium precipitate slag to the sodium hydroxide solution is 1:4-1:6 g / mL.

5. The method for recovering germanium and tannin from tannin germanium precipitation residue according to claim 1, characterized in that: The adding of lime adjusts the pH value of the mother liquor to 4-5.