An efficient and environmentally friendly process for the reduction of SO by using waste phosphate mine tailings as adsorbent.

The emission of SO and the disposal of waste phosphate mine tailings are generally regarded as two major environmental issues in phosphorus chemical activities. In this paper, an environmentally friendly and efficient route for removing SO from phosphorus chemical processes by using waste phosphate mine tailings as adsorbent was proposed. It was indicated that the desulfurization performance of the waste phosphate mine tailings was better than that of its raw ore. The characterization analysis illustrated that higher content of CaMg(CO) was shown on the waste phosphate mine tailings, which played a dominant role in determining the better desulfurization activity. In contrast, the accumulation of PO and H ions resulted from the dissolution of Ca(PO)F on the raw ore caused negative effect on SO removal. In the typical desulfurization system, the produced sulfuric acid from desulfurization process was used to decompose phosphate mine tailings, and these spent tailings can be subsequently applied as raw materials for the production of phosphorus products. As a result, the present approach can achieve the dual goal of reducing the cost of desulfurization process and recycling the waste tailings, which is of great environmental and economic significance.