The coal company’s pursuit of water management solutions was born from a strong need to conserve fresh water in densely populated China where this resource per capita is about one quarter of the global average at 2200 cubic metres.
This shortage is even worse in key Chinese coal fields.
“In 2013, 71% of the coal produced in China came from Western China, an area comprising Shanxi, Shaanxi, Inner Mongolia, Gansu and Ningxia,” WCA said.
“This area's per capita water resource is just 927 cubic metres.”
To feasibly tackle the issue, Shenhua invested in researching the potential of storing water in goaf areas of its underground mines which, on average, capture two tonnes of seeped water for every tonne of coal they produce.
In 1998 this culminated in Shenhua’s first goaf water storage facility, capable of holding 50,000 cubic metres of water.
WCA said it established the “first true coal mine underground reservoir” in 2006 which could contain 600,000cu.m over four square kilometres.
In 2010 Shenhua built the world’s first distributed underground reservoir in the Shendong Daliuta coal mine with the four linked reservoirs holding up to 7.1 million cu.m of water – eliminating 270cu.m per hour of mine water that was previously wasted.
“Daliuta was followed by Bulianta, Shangwan, Wulanmulun and other mines in the Shendong mining area,” WCA said.
“Shenhua Group now operates 32 underground reservoirs there, with a total capacity of 32 million cubic metres. Between 2011 and 2013, these reservoirs saved 85 million cubic metres of water.
“Far from making local water shortages worse as they first feared, Shenhua Group's mine water reservoirs now supply the Shendong mining area's power plants, industrial sites and homes with 95% of the water they need.
“The company is now applying its underground reservoir technology in other mining areas, including Baotou and Xinjie – and considers it well worth commercialising to help coal miners in other arid areas of the world.”
A more detailed case study is available from the WCA website.