Cementitious material and production method thereof

A method for producing a cementitious material, which comprises steps of:

• (1) dry desulfurization and denitrification of a flue gas with a flue gas absorbent to give a by-product, wherein the flue gas absorbent comprises 12-22 parts by weight of a nano-sized metal oxide, 12-20 parts by weight of a micro-sized metal oxide, and 42-60 parts by weight of magnesium oxide,
• wherein the nano-sized metal oxide comprises Fe2O3, V2O5 and MnO2, and the micro-sized metal oxide comprises Fe2O3, V2O5 and MnO2;
• wherein Fe2O3, V2O5 and MnO2 in the nano-sized metal oxide are at a weight ratio of 3-5:3-8:5-10, and Fe2O3, V2O5 and MnO2 in the micro-sized metal oxide are at a weight ratio of 3-5:3-8:5-10;
• and
• (2) uniformly mixing the by-product with magnesium oxide, an industrial solid waste and an additive to give the cementitious material, wherein the industrial solid waste is selected from one or more of the group consisting of fly ash, a slag powder, and a construction waste powder, and the additive is selected from one or more of the group consisting of dihydrogen phosphate, monohydrogen phosphate, tartaric acid, tartrate and amino trimethylene phosphonic acid, wherein the by-product, magnesium oxide, the industrial solid waste and the additive are at a weight ratio of 100:100-150:100-130:5-8.