Not sure why our colleague marked my response as correct answer. I'm so sorry for the mistake.
Upon checking with our server engineers, the Intel X520-LR1 Network Adapter is compatible with Intel® Server System R2312WTTYS. Please refer to the website below for the list of compatible hardware for Intel® Server System R2000WT Family:
Thank you for your patience and understanding. Feel free to contact us back if you have further inquiries.