| A general review of tin and antimony smelting technology is given, in this thesis which analyses the characterization and superiority of the Bath Smelting-Continuous Fuming process(the BS-CF process). This paper deals mainly with two parts, which is the study of the application of the BS-CF process to the high tungsten slag of tin smelting and to the treatment of low-grade antimony minerals.High tungsten tin electric furnace smelting slag has a high melting point and a hihg viscosity and there has no a suitable technique before in China to deal with it. After the characterization of the high tungsten slag of tin electrical furnace smelting. Bence trials of the liquid fuming process are conducted. The results of these trials show that visvosity and fnelting point of the slag can be aduusted by adding proper basic materials (such as remains of pyrites calcite, lime and hardhead) to the slag, which can achieve the technical conditions that are needed in the sulphidizing and fuming process.In the pilot plant employing fuming furnaces of 4m2 to which the results from bench trials are applied, as a result, the volatility of 96%, direct recovery of 93.5%, low tin content of 0.2% (the lowest being 0.05%) in the disposal waste, coal expense of 4.6 ton per ton tin, ratio of pyrite of 20.1% as well as tin content of 60% in the dust have been obtained. The process has been carried out on industrial plant with a suitable performance and targets.In order to investigate the performance of tungsten, silicon and other elements in the process, samples of fuming slag are picked up in site and studied by various methods of material phase analysis, X-ray diffraction, electric probe. The results indicate that almost all tungsten are presented in the scheelite, while silicon dioxide being present in Ca-fayalite (accounts for 80.17% ) and fayalite (accounts for 14.64% ) with adding basic materials, which produces a relatively lower melting point and viscosity to make the slag fluent enough to assure the reaction smooth. From the results other conclusion may also be made that the performance of tungsten does not change apparently, while silicon dioxide makes up of the lower melting point material with the adding basic material, which makes the accomplishment of the process. A high tungsten and silicon content in feeds will increase the melting point and viscosity of the feed material, which makes the reaction more difficult.In the pilot test, foaming occurred in some campaign and foam slag are produced. To have a deeper understanding of it, samples are taken in site and its characterization is also studied with thehelp of X-ray diffraction, electric probe and microscope determination. In the foam slags, 8162, A12O3 are found to have a higher content than those in tin electric furnace smelting slag and the fuming slag. The elements in the slag make up of vitroclastic in the form of oxides without crystal phase, which belongs to vitreous body, and few iron phases are found in the slag. The alkali degree of the foam slag is 0.97, which is much lower than that of the fuming slag. It belongs to acid slag in which positive ion is insufficient while anion is superfluous. The insufficiency of positive ion leads to a silicon saturation in the slag and a higher viscosity of the foam slag, which prevents a large amount of bulbs produced from escaping effectively as to make the slag a honeycomb-like structure, and mineral phases so that the final product proves to be vitreous phase. Feedings of alkali materials such as lime would increase positive ion content and lead to a higher alkali degree and a lower silicon saturation coefficient, which balances positive ions and anions in the slag, and forms crysolite-type slag. This is an effective method to eliminate foams so as to suppress the slag expanding, which guarantees the smooth operation of the smelting and fuming process.The results of slag chemistry reveal that high tungsten tin electric smelting slag belongs to subsatured slag with minority of saturated slag, the mineral t...
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