A new method for separating and recovering tin from a low-grade tin middling with high Si content and low Fe content by roasting with anthracite coal was researched by studying the reaction mechanism and performing an industrial test, in which the Sn was sulfurized into SnS(g) and then collected using a dust collector. The Fe-Sn alloy may be formed at roasting temperatures above 950°C, and like the roasting temperature increases, the Sn content and Sn activity in this Fe-Sn alloy decrease. Also, more FeS can be formed at higher temperatures and then the formation of FeO-FeS with a low melting point is promoted, which results in more serious sintering of this low-grade tin middling. And from the thermodynamics and kinetics points of view, the volatilization of the Sn decreases at extremely high roasting temperatures. The results of the industrial test carried out in a coal-fired rotary kiln show that the Sn volatilization rate reaches 89.7% and the Sn is concentrated in the collected dust at a high level, indicating that the Sn can be effectively extracted and recovered from the low-grade tin middling with a high Si content and low Fe content through a reduction—sulfurization roasting process.

通过研究无烟煤的反应机理并进行工业试验，研究了一种通过无烟煤焙烧从低品位的高硅含量低铁锡中分离和回收锡的新方法，并进行了工业测试，其中锡被硫化成SnS（ g），然后使用集尘器收集。可以在高于950℃的焙烧温度下形成Fe-Sn合金，并且随着焙烧温度的升高，该Fe-Sn合金中的Sn含量和Sn活性降低。同样，在更高的温度下可以形成更多的FeS，然后促进低熔点的FeO-FeS的形成，从而导致这种低品位锡熔渣的烧结更加严重。并且从热力学和动力学的观点来看，在极高的焙烧温度下，锡的挥发减少。