Abstract

Using the method of experiment planning by simplex, the surface tension of the melts of СаО–SiO₂–Al₂O₃–В₂O₃ system was researched. The local part of the system was explored which covered the process of ferrosilicon, silicochrome, cement clinker, ceramics, glass, and sittals production. The amount of oxides in it was (%): 9.8–52.0 CaO; 0–70.4 SiO₂; 0–51.5 Al₂O₃, and 0–20 B₂O₃. A mathematical model of surface tension dependence on the melt composition has been created and diagrams in the form of tetrahedron sections in B₂O₃ have been constructed. In the CaO–SiO₂–Al₂O₃ system, which is the basis for metallurgy, melts with a high surface tension adjoin the binary side of CaO–Al₂O₃ in the calcium aluminate crystallization area which have small sizes, high charge and, thus, bond to melt volume. With the introduction of SiO₂, σ of melts decreases due to the formation of large aluminosilicon formations of the [Al₂Si₂O₈]^2– type, rankinite groups Si₂\({\text{O}}_{7}^{{6 - }}\), and ring complex [Si₃O₉]^6– pseudo-wollastonite anion. The anion complication due to polymerization leads to a drop of surface tension because of a decrease in charge ratio of the latter to the radius and, consequently, the strength of bond with cations. Boron anhydride injection causes a decrease in surface tension of melts СаО–SiO₂–Al₂О₃, which can be explained by boron transition at high temperature from four oxygen-coordinated (\({\text{BO}}_{4}^{{5 - }}\)) to three oxygen-coordinated state (\({\text{BO}}_{3}^{{3 - }}\)). Formed flat triangles \({\text{BO}}_{3}^{{3 - }}\) or complexes with them are loosely related to the melt’s volume, forced out to the surface and reduce surface tension. Mostly, this affects the main aluminate melts, rather than acid ones. The latter can be explained by the capillary activity closeness of boron- and silicon-oxygen anions. The surface phenomena between the products of blast-furnace smelting of titanomagnetite iron ores have been studied experimentally using the lying drop method. It was noted that the highest adhesion forces (work of adhesion) take place between slag and grenal (cast iron with a high titanium and silicon content), which is the reason for the metal loss at the outlet with slags during the processing of such ores. Boron loaded into the blast furnace (in the form of natural ores) is redistributed under reduction conditions between cast iron, grenal and slag. Experiments have shown that the presence of boron in slag at the level of microconcentrations reduces the work of adhesion from 688 to 436 MN/m (by 37%). Industrial experiments have shown that this helped to reduce the loss of valuable vanadium-containing cast iron with slags by 1.2–1.5 times with a simultaneous improvement in smelting performance.

中文翻译：

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CaO–SiO2–Al2O3–B2O3体系的熔体表面张力

摘要

使用由单一实验规划的方法，СаО-的SiO的熔体的表面张力₂ -Al ₂ ö ₃ -В ₂ ö ₃系统进行了研究。探索了该系统的本地部分，该部分涵盖了硅铁，硅铬铁，水泥熟料，陶瓷，玻璃和锡塔铁的生产过程。其中的氧化物含量为（％）：9.8-52.0 CaO；0–70.4 SiO ₂；0-51.5 Al ₂ O ₃和0-20 B ₂ O ₃。已经建立了表面张力对熔体成分的依赖性的数学模型，并以B ₂ O _3中的四面体截面形式绘制了图表已建成。在作为冶金基础的CaO-SiO ₂ -Al ₂ O ₃系统中，具有高表面张力的熔体与铝酸钙结晶区域中的CaO-Al ₂ O ₃的二元面邻接，具有小尺寸，高电荷因此，结合到熔体体积上。随着SiO ₂的引入，熔体的σ降低，这是由于形成了[Al ₂ Si ₂ O ₈ ] ^2–型的大型铝硅晶格，形成了兰科岩群Si ₂ \（{\ text {O}} _ {7} ^ {{{6-}} \）和环复合物[Si ₃ O ₉ ] ^6–假硅灰石阴离子。由于聚合引起的阴离子复杂化导致表面张力降低，这是由于表面电荷与半径的电荷比降低，因此，与阳离子的键合强度降低。硼酐注入导致熔体的表面张力的降低СаО-的SiO ₂ -Al ₂ О ₃，其可通过硼过渡在高温下从进行说明四个氧配位的（\（{\文本{BO}} _ {4} ^ {{{5-}} \））到三个氧配位状态（\（{\ text {BO}} _ {3} ^ {{3-}} \））。形成的扁平三角形\（{\ text {BO}} _ {3} ^ {{3-}} \）或与它们形成的络合物与熔体的体积松散相关，被迫排到表面并降低表面张力。通常，这会影响主要的铝酸盐熔体，而不是酸性的熔体。后者可以通过硼和硅氧阴离子的毛细管活性接近性来解释。钛磁铁矿铁矿高炉冶炼产品之间的表面现象已通过落滴法进行了实验研究。值得注意的是，最高的附着力（附着力）发生在炉渣和粗晶（钛和硅含量高的铸铁）之间，这是在此类矿石加工过程中，炉渣出口处金属损失的原因。装入高炉中的硼（以天然矿石的形式）在还原条件下在铸铁，坯料和炉渣之间重新分配。实验表明，矿渣中微量浓度的硼的存在将附着功从688降低到436 MN / m（降低了37％）。工业实验表明，这有助于将有价值的含钒铸铁随炉渣的损失减少1.2-1.5倍，同时提高了冶炼性能。