IM 2017 April | Page 81

MINERAL PORTS economical price. China Coal sought storage facilities for both its Hulusu and Menkeqing coal mines, located 15 miles apart in north China’s Inner Mongolia province. Based on “their ability to keep out outside moisture,” Bateman said a series of domes was a more economical solution than traditional silos. But the aesthetics were also very important to the customer. Today, one mine has three identical domes housing 60,000 t of coal apiece and in the distance there are three more identical domes at the other mine. An innovative material-handling system inside the domes gave China Coal what it wanted most: the ability to move product and move it fast. And demand for energy coal in China is continually growing. “China is an emerging country, and they have an energy shortage— that’s why companies like this are developing in this region,” Bateman said. Inside each dome, a full hopper system similar to a series of funnels situated side by side allows coal to flow through the structure under its own weight rather than by loader. “Inside this dome it’s a 100% live-reclaim system, which is not new to the industry, but on this magnitude, it’s pretty new,” Bateman said, adding that this design allows each dome to be completely emptied every three days. Other design details also add value, especially since the possibility of coal self-igniting in the dome was one of the main concerns, according to Zhao Jiapeng of China Coal. The PVC membrane outside the dome prevents moisture from entering and contributing to spontaneous combustion. Secondary explosions—the kind caused when initial explosions shake loose accumulated coal dust—are less likely because the support-free domes have no ledges for dust to build up. The domes’ design also allows China Coal to render the pile of coal inert by sealing the top and bottom to cut off oxygen sources and by pumping nitrogen to lower the oxygen level. At each site, Dome One, located closest to the mine, houses coal coming fresh from the mine until exiting the dome, passing through a cleaning and washing process before being milled to achieve the right-sized pieces. From there coal is dumped via conveyor into Domes Two and Three, where it later exits the structures in one of three tunnels and is transported to trains waiting just outside. Bucket wheels well suited to hydraulic drives Bucket wheel rec