Gypsum waste, with CaSO₄·2H₂O as the main ingredient, decomposed into SO₂(g) at a proper temperature, according to previous research. It could sulfurize SnO₂ to SnS(g) in the presence of C or CO(g), based on which a method of roasting with gypsum waste (CaSO₄·2H₂O) for removing Sn from Sn-bearing iron concentrates was put forward in this paper. In addition, a traditional curing agent, FeS₂, was introduced and comparatively studied. With FeS₂ used as the curing agent for tin sulfurization and removal, the FeS generated from the FeS₂ decomposition played a major role through its transformation to SO₂(g) and COS(g) in mixed gases of 35 vol.%CO and 65 vol.%CO₂. Besides, the COS(g) had a better sulfurization effect on tin than SO₂(g). The ‘S’ from gypsum waste (CaSO₄·2H₂O) was mainly transformed into FeS and Ca₃Fe₄S₃O₆ upon roasting with tin-bearing iron concentrate in mixed gases of 35 vol.%CO and 65 vol.%CO₂, both of which could sulfurize Sn(l) to SnS(g) also through their transformation to SO₂(g) and COS(g). The amount of sulfur added by CaSO₄·2H₂O could be decreased compared with that added by FeS₂ due to the higher utilization efficiency of ‘S’ in CaSO₄·2H₂O. This process realized the cyclic utilization of gypsum waste, Sn effective removal and the iron pre-reduction from tin-bearing iron concentrate.

根据以前的研究，以CaSO ₄ ·2H ₂ O为主要成分的石膏废料在适当的温度下分解为SO ₂（g）。可以在C或CO（g）存在下将SnO ₂硫化成SnS（g），据此提出了一种用石膏废料（CaSO ₄ ·2H ₂ O）焙烧的方法，从含锡铁精矿中去除Sn。本文向前。另外，引入和比较研究了传统的固化剂FeS ₂。FeS ₂用作硫化锡和去除锡的固化剂，由FeS ₂分解生成的FeS通过转化为SO起到了主要作用₂（g）和COS（g）在35 vol。％CO和65 vol。％CO _2的混合气体中。此外，COS（g）对锡的硫化作用要优于SO ₂（g）。用含锡铁精矿在35％（体积）的CO和65％（体积）的混合气体中焙烧时，石膏废料（CaSO ₄ ·2H ₂ O）中的“ S”主要转化为FeS和Ca ₃ Fe ₄ S ₃ O ₆。 ％CO ₂，它们也都可以通过转化为SO ₂（g）和COS（g）而将Sn（l）硫化为SnS （g）。与FeS相比，可以减少CaSO ₄ ·2H ₂ O添加的硫量₂由于在的CaSO“S”的更高利用效率₄ ·2H ₂ O.这种处理来实现的石膏废物，锡有效去除和铁预还原从含锡铁精矿的循环利用。