Mechanism of Iodine Enrichment in Phosphorite of Late Sinian, SW China

Abstract

Yangtze platform Doushantuoian is the first large-scale phosphorous forming peak period of China, and the sedimentary phosphorite is widely distributed in south China, at same time, this area have phosphorous deposits with abundant iodine element. Especially, the phosphorite occurred in the Doushantuo formation in the Late Ediacaran in Central Guizhou features the highest iodine, with the content achieving 76 mg kg -1 (Zhou 1984; Zhang et al., 2003). In 20 th century many countries extract the iodine from the phosphorite, hovever, the process flow was complicated the production cost was too high and the industrialized production was not realized (Zhang et al., 2011; Reich et al., 2013). In 2007, Wengfu (Group) Co., Ltd. extracted the iodine from the processing of the phosphorite successfully. The proved phosphate ore reserve of the whole Guizhou Province is 2.7 billion tons. There is a large reserve of associated iodine resource, for instance, the Yingping ore block of Wengfu phosphate ore has associated iodine reserve of almost 7,000 t (Zhang et al., 2011). However, the previous researches all focus on the mineral processing technology, only few of them related to the enriching reasons and rules, occurrence states and control factors of the iodine in the phosphorite, which becomes as a point of departure and priority to this research work.