Ma Yumin of Ling Gang has no retirement information. According to relevant public information, Ma Yumin, with a university degree and party member, is a senior engineer. He is currently the director of Chaoyang Coking Co., Ltd. of Ling Gang Group, the chairman of Ling Gang Lingyuan Renewable Resources Development Co., Ltd., the chairman of Lingyuan Iron and Steel Transportation Co., Ltd., the director of Chaoyang Longshan Asset Management Co., Ltd., the director of Ningcheng Yishan Mining Co., Ltd., the director of Jianping Phosphate Iron Mine Co., Ltd., and the director and general manager of Lingyuan Iron and Steel Co., Ltd., up to now 65,438.