Method for preparing portland cement featuring early strength, low shrinkage, and low heat

A method for preparing Portland cement, the Portland cement comprising 90-97 parts by weight of a cement clinker and 3-10 parts by weight of gypsum;

• the cement clinker being obtained by calcining cement raw materials comprising:
• 10-20 parts by weight of marble, 3-5 parts by weight of fluorite, 20-35 parts by weight of dolomite, 2-9 parts by weight of quartz, 8-12 parts by weight of mica, 2-3 parts by weight of kaolinite, 2-5 parts by weight of prefabricated iron slag, 3-4 parts by weight of prefabricated copper slag, 8-15 parts by weight of prefabricated vanadium slag, and 5-13 parts by weight of prefabricated nickel slag;
• and the method comprising:
• 1) respectively weighing iron slag, copper slag, vanadium slag, and nickel slag and grinding, to yield the prefabricated iron slag, the prefabricated copper slag, the prefabricated vanadium slag, and the prefabricated nickel slag;
• 2) weighing the mica and the kaolinite, mixing, and grinding to obtain aluminous raw materials;
• 3) evenly mixing the prefabricated iron slag and the aluminous raw materials, and calcining, to yield an iron-aluminum eutectic mineral;
• 4) weighing the marble, fluorite, dolomite, and quartz, evenly mixing the marble, fluorite, dolomite, and quartz with the prefabricated copper slag, prefabricated vanadium slag, and prefabricated nickel slag to yield a first mixture;
• grinding the iron-aluminum eutectic mineral to yield powders, and calcining a second mixture of the first mixture and the powders, to yield the cement clinker;
• and
• 5) cooling the cement clinker, and grinding a third mixture of the cooled cement clinker and the gypsum, to yield the Portland cement.