The manufacturing method of "Portland cement" described in his patent certificate is: "Mash limestone into fine powder, add a certain amount of clay, mix it with water, and stir it into slurry manually or mechanically. Put the mud on a plate and heat it to dry. The dry material is crushed into blocks, and then put into a lime kiln for calcination until the carbonic acid gas in limestone completely escapes. The calcined clinker is cooled, crushed and ground to make cement. When cement is used, a small amount of water is added and stirred into mortar with appropriate consistency, which can be applied to various workplaces. "
The color of this cement after hydration and hardening is similar to the color of building stone in Portland, England, so it is called "Portland cement". Reference/Question /26447563.html