Hunan Sanan Mining Co., Ltd. is a wholly-owned subsidiary of Fujian Sanan Group Co., Ltd. It owns Qidong Duijiachong Iron Mine and Hengyang Miaochong Iron Mine, and is the largest enterprise in Hunan Province that produces and sells iron concentrate.

In 2007, Hongda Blasting's subsidiary Xinhua Du Engineering undertook the mining projects of Duijiachong and Miaochong iron mines, and has been cooperating for more than ten years. In May 2021, Hongda Blasting signed a general contract with Sanan Mining for the mining, selection, construction, production and operation of Miaochong Duijiachong iron mine, including open-pit mining, underground mining, beneficiation and production operation. Miaochong Iron Mine is a difficult to select and poor iron ore. After Hongda blasting took over the beneficiation plant, it underwent a phase one technological transformation and upgrade, building two advanced production lines with ultra-fine particle size. It adopts a three-stage closed-circuit crushing, three-stage grinding, selective flocculation desliming, and anion reverse flotation new process, which has successfully overcome the difficulties of difficult, fine, and miscellaneous ore selection.