Hello, we are couple of Kazakhstan citizens. Can we get chinese visa in Hanoi?

This winter we are planning to have a 4-month tour from Kazakhstan-to China and then to Vietnam and back. Here in Kazakhstam due to elections in China we cannnot make multiply chinese visa, only single entry visa. So can we take firstly visa to China in Kazakhstan and then after 3 month on a way back home from Vietnam get the same single visa to China in Hanoi? Many thanks for your attention/