Method for preparing general-purpose cement

A method for preparing a general-purpose cement, comprising:

• step (1) mixing one or more raw materials to obtain a raw meal containing SiO2, Al2O3, CaO, MgO, and Na2O or K2O;
• and subjecting the raw meal to drying and grinding to obtain a raw meal powder;
• step (2) oxidatively calcining the raw meal powder at no less than 1210° C. for a time long enough to obtain a stable phase state, followed by cooling to obtain a clinker predominated by a glass phase;
• wherein a mass percentage of SiO2+Al2O3+Fe2O3+CaO+MgO+Na2O+K2O in the clinker is no less than 93%, and in every 100 parts (by mass) of SiO2+Al2O3+Fe2O3+CaO+MgO+Na2O+K2O, a mass distribution is:
• SiO2 31.5˜44.8, Al2O3 6.1˜19.9, Fe2O30˜6.2, CaO 22.5˜45.0, MgO 1.2˜16.0, Na2O+K2O 1.0˜8.3;
• and
• step (3) mixing the clinker with NaOH, KOH or a combination thereof followed by grinding to obtain the general-purpose cement;
• or
• grinding the clinker to obtain a clinker powder, and mixing the clinker powder with a NaOH aqueous solution, a KOH aqueous solution or a combination thereof for use;
• wherein NaOH, KOH or a combination thereof is added such that a weight ratio of NaOH+0.713KOH to the clinker is 0-0.03:1.