Where do people get their information from. Lafarge is the biggest producer of cement in the world with plants and mines all over the world. They are also the biggest building supplier in the world including cement, concrete, roofing etc. Where is this idea that the the USA only produces 6 to 8 million tonnes of cement per year.In 1981 Lafarge acquired portland cement that had a capacity of 6 million tonnes per year at that time. That is only one company twenty five years ago. Do the reasearch. Look up Lafarge and you will see.