Ten million jin of crude iron a year meant five thousand tonnes of crude iron a year. Although this might be the daily production of a small steel mill back in Yan Liqiang's previous world, this amount was still considered a very large scale iron ore production in the Great Han Empire. To Gan Province or the entire Great Han Empire, this iron mine at Mount Kang was certainly of an impressive scale. Taking out the production cost, it was estimated to generate an annual profit of more than seventy or eighty thousand taels of silver.