Abstract

The pyrometallurgical production of germanium concentrates from the raw materials (coal, argillite, siltstone) of brown coal fields is accompanied by the formation of molten silicate slags. The mineral component of the raw materials concentrates in slags, reaching 60 wt %. It is obvious that the process indices are mainly determined by the physicochemical properties of the molten slags, such as density ρ and surface tension σ, reflecting the structure of molten silicates. The compositions of the slags after processing of carbonaceous raw materials differ significantly from those of the slags of nonferrous and ferrous metallurgy: they contain higher contents of SiO₂ (up to 50–55%), Al₂O₃ (up to 20–22%), K₂O, and Na₂O (up to 5–6%). In addition, the slags contain significant contents of sulfide sulfur (up to 3%) and trace amounts of nonferrous metals and rare elements (up to 5%). The differences between the compositions of the molten slags of germanium production and the slags of main metallurgy influence their properties and require special studies. Industrial cyclone melting and electric smelting slag samples are studied. Semi-synthetic samples are analyzed; these samples are produced from industrial ones by the addition of SiO₂ and CaO in order to determine the influence of composition on ρ and σ. The measurements are based on the maximum pressure in an inert gas bubble blown in a melt, more specifically, on the differential version to improve the accuracy. The cell consists of the melt to be studied in an alundum crucible with an immersed alundum capillary and a reference capillary immersed into distilled water. The melt temperature is measured in the range 1100–1400°C. ρ and σ of the melts are found to fall in the ranges from 2.20 to 4.3 t/m³ and from 218 to 531 mN/m, respectively. The values of ρ and σ significantly depend on the basicity (ratio of the sum of the CaO and MgO contents to SiO₂) and the Al₂O₃ content. The temperature dependences of ρ and σ are found to be linear with negative temperature coefficients. In the general case, ρ and σ of the melts significantly differ from, for instance, the blast furnace slags at the same basicity. The obtained results are valuable for predicting the structures of melts and their behavior under real conditions.

中文翻译：

---

精矿锗熔渣的密度和表面张力

摘要

从褐煤田的原料（煤，泥锌矿，粉砂岩）进行火法冶金生产锗精矿会伴随着熔融硅酸盐矿渣的形成。原料的矿物成分集中在炉渣中，达到60 wt％。显然，工艺指标主要取决于熔渣的物理化学性质，例如密度ρ和表面张力σ，反映了熔融硅酸盐的结构。含碳原料加工后的炉渣成分与有色和黑色冶金炉渣的成分明显不同：它们包含较高含量的SiO ₂（最高50-55％），Al ₂ O ₃（最高20-22） ％），K ₂ O和Na ₂O（最高5–6％）。另外，这些炉渣中含有大量的硫化物硫（最高3％）以及痕量的有色金属和稀有元素（最高5％）。锗生产熔渣和主要冶金渣的成分之间的差异会影响其性能，需要进行特殊研究。研究了工业旋风熔炼和电熔渣样品。分析半合成样品；这些样品是由工业样品通过添加SiO ₂制成的和CaO，以确定成分对ρ和σ的影响。这些测量基于熔体中吹入的惰性气泡中的最大压力，更具体而言，基于微分形式以提高精度。该池由待研究的熔体组成，该熔体要在具有浸入的刚玉毛细管和浸入蒸馏水中的参比毛细管的刚玉坩埚中进行研究。熔体温度的测量范围为1100–1400°C。发现熔体的ρ和σ分别落在2.20至4.3t / m ³和218至531mN / m的范围内。ρ和σ的值很大程度上取决于碱度（CaO和MgO含量之和与SiO _2的比）和Al ₂ O ₃内容。发现ρ和σ的温度依赖性与负温度系数呈线性关系。在一般情况下，熔体的ρ和σ与例如高炉矿渣在相同的碱度下明显不同。获得的结果对于预测熔体的结构及其在实际条件下的行为是有价值的。