Method for back extraction of germanium from germanium-contained fluosilicic acid solution

Abstract

The invention relates to the technical field of hydrometallurgy, in particular to a method for back extraction of germanium from a germanium-contained fluosilicic acid solution. The germanium-contained fluosilicic acid solution is extracted with an N235-kerosene system serving as an organic phase, a sodium hydroxide solution containing ammonium ions is adopted for treating the organic phase, sulfuric acid is added to a back extraction solution to adjust the PH value, then, germanium hydrolysis treatment is performed, obtained precipitate is calcined, germanium is obtained, and the quality of germanium concentrate is further improved, so that in the germanium concentrate, the content of germanium is larger than or equal to 7%, the content of F is smaller than 0.5%, and the content of Si is smaller than 4%; the extraction rate of germanium in germanium-contained fluosilicic acid is increased, and the extraction cost of germanium in the germanium-contained fluosilicic acid solution is reduced.

Description

technical field [0001] The invention relates to the technical field of hydrometallurgy, in particular to a method for stripping germanium from a germanium-containing fluorosilicate solution. Background technique [0002] The raw material containing germanium and high silicon is treated by acid leaching with fluoride, and then produced by tannin precipitation method, which has high production cost and low yield. Therefore, some researchers applied N to the germanium-containing fluorosilicate solution obtained after the germanium-containing high-silicon raw material was treated with fluoride acidic leaching. 235 Ge was extracted under the condition of adding Ge complexing agent, and NaOH solution was used for alkaline stripping. The extraction rate of Ge in this process is all above 90%, but its stripping is not complete, and the purity of stripped germanium is low, and then causes, N 235 The regeneration of the organic phase is not good, and the extraction rate is getting l...

AI Technical Summary

Problems solved by technology

The extraction rate of Ge in this process is all above 90%, but its stripping is not complete, and the purity of stripped germanium is low, and then causes, N 235 The regeneration of the organic phase is not good, and the extraction rate is getting lower and lower as the extraction-stripping cycle continues

Even if it is N 235 Poor regeneration of the organic phase, which in turn makes the extraction and stripping of germanium more expensive

And the reason that produces such technical problem is: N 235 While Ge is extracted, Si and F are also partially extracted, but only NaOH stripping is used, and the stripping of Ge, Si, and F is not complete; and the stripped Si exists in the NaOH solution in the form of sodium silicate. Solubility is not high, and the solubility of F in NaOH solution is not high in the form of NaF, which is easy to produce crystal precipitation, which affects the phase separation resolution and phase separation speed of alkali stripping, and then hinders the carrying out of alkali stripping germanium, increasing The cost and difficulty of alkali stripping treatment

[0003] For this reason, further research and discussion have been made by researchers in combination with the above-mentioned defects, that is, CaCl is used before and after alkali stripping. 2 The solution is washed with the organic phase in order to replace Si with CaSiO 3 , F and CaF 2 eluted, but due to CaSiO 3 and CaF 2 Both are compounds with low solubility, when CaCl 2 When the washing solution is repeatedly washed, a large amount of sediment will be produced, which will separate the organic phase and make it difficult to settle. CaCl must be replaced every time. 2 washing solution, resulting in CaCl 2 The amount of washing liquid is large, and the amount of waste water generated is large

At the same time Cl - Under alkaline conditions to be N 235 Partial extraction, the regeneration of the organic phase is not good, and the extraction rate of Ge will be affected when it is returned to use