What are the regular spot trading platforms in China?

There are Hengqin Precious Metals Trading Center, Qingdao Zhengyuan Hengbang Precious Metals Trading Center, Hunan Huaxia Yindu Commodity Trading Center, Sichuan Chuanshang Commodity Trading Center, Guangdong International Commodity Trading Center, Xinhua Shanghai Precious Metals Trading Center and Hunan Yinlou Spot Commodity Trading Market.