Process for leaching germanium by modifying germanium-containing aluminosilicate

Abstract

The invention discloses a process for leaching germanium by modifying germanium-containing aluminosilicate, which belongs to the technical field of solid waste recycling and comprises the following steps: mixing germanium-containing aluminosilicate and industrial concentrated sulfuric acid with the mass concentration of 98% to prepare concentrated slurry; (2) carrying out sulfating roasting on the concentrated slurry in a smelting furnace to obtain roasted ore; (3) adding water into the roasted ore, carrying out acid leaching in a reaction tank, and carrying out liquid-solid separation to obtain a leaching solution rich in germanium; according to the method, the germanium in the germanium-containing aluminosilicate is extracted by adopting a sulfating roasting-water leaching process, insoluble silicate and silicon dioxide are converted into silicate of a soluble acidic aqueous solution by utilizing sulfating roasting, so that efficient leaching of the germanium is realized, the process flow is simple, the concentration of the germanium in the leachate is high, subsequent separation and recovery of the germanium are facilitated, and the method is suitable for industrial production. And comprehensive resource recycling of the lignite smoke dust is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to a process for modifying leaching germanium from germanium-containing silicate aluminates, belonging to the technical field of solid waste resource utilization. BACKGROUND

[0002] Germanium is an important strategic metal resource, and there are very few germanium deposits that can be independently mined in nature. However, due to its affinity for sulfur, iron, and silicon, it is usually present in high content in sphalerite and lignite. Therefore, the current recovery of germanium is mainly from the extraction of associated germanium in zinc smelting and the recovery of germanium from coal ash in lignite combustion.

[0003] In the wet smelting process of sphalerite, in addition to the process of direct oxygen pressure leaching of germanium-containing zinc concentrate and separation of germanium-rich solution, there is also a process of obtaining germanium-rich zinc oxide dust through traditional zinc leaching slag pyrometallurgical reduction volatilization, and then separating and enriching germanium from the dust through sulfuric acid leaching. The recovery of germanium from germanium-containing lignite is mainly the separation and extraction of germanium from coal ash in lignite combustion.

[0004] Due to the presence of a certain amount of insoluble silicon in zinc oxide dust and coal ash from lignite combustion, the leaching rate of germanium is limited. In particular, most of the germanium in coal ash from lignite combustion is present in insoluble silicate aluminates, which is more difficult to recover than germanium in zinc smelting process containing zinc oxide dust. There are many process methods, and some enterprises currently use methods including: coal ash pyrometallurgical reduction smelting to prepare iron germanium alloy, coal ash secondary reduction volatilization to enrich germanium, coal ash alkali fusion water leaching, and coal ash hydrofluoric acid leaching.

[0005] Pyrometallurgical reduction smelting to prepare iron germanium alloy and coal ash secondary reduction volatilization to enrich germanium are processes that secondarily enrich germanium in coal ash before leaching. Coal ash alkali fusion water leaching and coal ash hydrofluoric acid leaching are processes that directly leach germanium in coal ash to obtain a germanium-containing solution. Although the above methods have achieved certain results, they generally have the problem of low germanium recovery rate. The main reason is the dispersion of germanium and the generation of insoluble germanium-containing silicate aluminates during alkali fusion. Direct leaching process is limited by the presence of germanium-containing silicon dioxide in coal ash, making it difficult to leach germanium. In addition, due to the current recovery of germanium mainly using an acidic system, the alkali fusion method is limited to some extent. SUMMARY

[0006] In view of the low leaching (recovery) rate of germanium in germanium-containing silicate aluminates, the present application provides a process for modifying leaching germanium from germanium-containing silicate aluminates. The process uses sulfuric acid roasting-water leaching to extract germanium from germanium-containing silicate aluminates. Sulfuric acid roasting is used to convert insoluble silicates and silicon dioxide into easily soluble acid-soluble silicates, thereby achieving efficient leaching of germanium. The process is simple, the germanium concentration in the leaching solution is high, and it is easy to separate and recover germanium in the subsequent process, which is conducive to the comprehensive recovery and utilization of lignite dust resources.

[0007] In order to achieve the above object, the process for modifying germanium-containing silico-aluminate to leach germanium comprises the following steps: (1) mixing the germanium-containing silico-aluminate with industrial concentrated sulfuric acid with a mass concentration of 98% to prepare concentrated slurry; The germanium-containing silico-aluminate comprises the following components: germanium content of 4000-8000 g / t, silicon content of 10-25 wt%, aluminum content of 8-18 wt%, iron content of 5-15 wt%, and calcium content of 5-10 wt%; The germanium-containing silico-aluminate is mixed with industrial concentrated sulfuric acid with a mass concentration of 98% at a mass ratio of 0.5-1:1; (2) performing sulfuric acid roasting of the concentrated slurry in a smelting furnace to obtain roasted ore; The reaction temperature of the roasting is 500-800 ℃, and the reaction time is 1-2 h; (3) adding water to the roasted ore in a reaction tank to perform acid leaching, and then performing liquid-solid separation to obtain leaching solution rich in germanium.

[0008] The liquid-solid ratio mL: g of the water to the roasted ore is 5-8:1, the acid leaching temperature is 80-90 ℃, the reaction time is 2-3 h, and the terminal pH value is 0.5-2.5.

[0009] The germanium-containing silico-aluminate is mixed with industrial concentrated sulfuric acid with a mass concentration of 98% at a mass ratio of 0.5-1:1; DETAILED DESCRIPTION

[0010] The technical solutions of the present application will be further described in detail below in combination with specific embodiments, but the present application is not limited to the following technical solutions; unless specifically stated, the reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the technical field; those skilled in the art can refer to various conventional toolbooks, scientific and technical literature or related specifications, manuals and the like before the application date of the present application to implement them; Example 1: The process for modifying germanium-containing silico-aluminate to leach germanium comprises the following steps: (1) mixing the germanium-containing silico-aluminate with industrial concentrated sulfuric acid with a mass concentration of 98% to prepare concentrated slurry; (2) The concentrated slurry is placed in a smelting furnace, and sulfuric acid roasting is carried out at a reaction temperature of 650°C for 1.5h to obtain a roasted ore; (3) The roasted ore is added with water at a liquid-solid ratio mL: g of 8: 1, and placed in a reaction tank for acid leaching at 85°C for 3h to obtain a leaching ore slurry with a final pH value of 0.97, and a germanium-rich leaching solution is obtained after liquid-solid separation.

[0011] The germanium leaching rate of this embodiment is 95.86%, and the germanium content of the leaching solution is 0.56g / L.

[0012] Example 2: The process for modifying and leaching germanium from the germanium-containing silicate is as follows: (1) The germanium-containing silicate with a germanium content of 4138.92g / t, a silicon content of 24.87wt%, an aluminum content of 8.26wt%, an iron content of 14.36wt%, and a calcium content of 5.07wt% is mixed with industrial concentrated sulfuric acid with a mass concentration of 98% to prepare a concentrated slurry at a mass ratio of 1:1; (2) The concentrated slurry is placed in a smelting furnace, and sulfuric acid roasting is carried out at 800°C for 1h to obtain a roasted ore; (3) The roasted ore is added with water at a liquid-solid ratio mL: g of 5: 1, and placed in a reaction tank for acid leaching at 90°C for 2h to obtain a leaching ore slurry with a final pH value of 0.53, and a germanium-rich leaching solution is obtained after liquid-solid separation.

[0013] The germanium leaching rate of this embodiment is 90.28%, and the germanium content of the leaching solution is 0.43g / L.

[0014] Example 3: The process for modifying and leaching germanium from the germanium-containing silicate is as follows: (1) The germanium-containing silicate with a germanium content of 4138.92g / t, a silicon content of 24.87wt%, an aluminum content of 8.26wt%, an iron content of 14.36wt%, and a calcium content of 5.07wt% is mixed with industrial concentrated sulfuric acid with a mass concentration of 98% to prepare a concentrated slurry at a mass ratio of 1:1; (2) The concentrated slurry is placed in a smelting furnace, and sulfuric acid roasting is carried out at 500°C for 2h to obtain a roasted ore; (3) The roasted ore is added with water at a liquid-solid ratio mL: g of 6: 1, and placed in a reaction tank for acid leaching at 80°C for 3h to obtain a leaching ore slurry with a final pH value of 2.48, and a germanium-rich leaching solution is obtained after liquid-solid separation.

[0015] The germanium leaching rate of this embodiment is 93.81%, and the germanium content of the leaching solution is 0.67g / L. Comparative Example 1

[0016] Comparative Example 1: The method of this example is the same as that of Example 1, except that the sulfating roasting of step (2) is not included, and is as follows: (1) A germanium-containing silico-aluminate with a germanium content of 7952.68 g / t, a silicon content of 19.53 wt%, an aluminum content of 13.95 wt%, an iron content of 11.83 wt%, and a calcium content of 8.27 wt% is mixed with industrial concentrated sulfuric acid with a mass concentration of 98% at a mass ratio of 0.78:1 to form a concentrated slurry; (2) The mixed slurry is added with water at a volume-to-mass ratio of 8:1, and is placed in a reaction tank to react at 85°C for 3h to perform acid leaching, and an end-point pH value of the leaching slurry is 0.12, and a germanium-rich leaching solution is obtained after liquid-solid separation; the calculated germanium leaching rate is 56.28%.

[0017] Comparative Example 2 (1) A germanium-containing silico-aluminate with a germanium content of 7952.68 g / t, a silicon content of 19.53 wt%, an aluminum content of 13.95 wt%, an iron content of 11.83 wt%, and a calcium content of 8.27 wt% is placed in a smelting furnace and is roasted at 650°C for 1.5h to obtain a roasted ore; (2) The roasted ore is added with water at a liquid-to-solid ratio of 8:1, and is placed in a reaction tank to react at 85°C for 3h to perform acid leaching, and an end-point pH value of the leaching slurry is 0.27, and a germanium-rich leaching solution is obtained after liquid-solid separation; the calculated germanium leaching rate is 63.75%.

[0018] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A process for leaching germanium by modifying germanium-containing aluminosilicate, characterized in that: The following steps are involved: (1) A germanium-containing aluminosilicate is mixed with 98% industrial concentrated sulfuric acid to prepare a concentrated slurry; (2) the concentrated slurry is subjected to sulfuric acid roasting in a smelting furnace to obtain a roasted ore; (3) the roasted ore is added with water and subjected to acid leaching in a reaction tank, and a germanium-rich leachate is obtained after liquid-solid separation.

2. The process for leaching germanium by modifying aluminosilicate containing germanium according to claim 1, characterized in that: The germanium-containing aluminosilicate comprises the following components: a germanium content of 4000-8000 g / t; a silicon content of 10-25 wt%; an aluminum content of 8-18 wt%; an iron content of 5-15 wt%; and a calcium content of 5-10 wt%.

3. The process for leaching germanium by modifying germanium-containing aluminosilicate according to claim 1, characterized in that: The germanium-containing aluminosilicate is mixed with industrial concentrated sulfuric acid with a mass concentration of 98% according to a mass ratio of the germanium-containing aluminosilicate to sulfuric acid of 0.5-1:

1.

4. The process for leaching germanium by modifying germanium-containing aluminosilicate according to claim 1, characterized in that: The reaction temperature of the sulfuric acid roasting is 500-800°C, and the reaction time is 1-2h.

5. The process for leaching germanium by modifying germanium-containing aluminosilicate according to claim 1, characterized in that: The liquid-solid ratio of water to roasted ore is 5-8:1 in mL:g, the acid leaching temperature is 80-90°C, the reaction time is 2-3h, and the end point pH value is 0.5-2.5.