Limestone is a rock mainly composed of calcium carbonate (CaCO3). Our high purity limestone is supplied to customers around the world after being sorted by size and application at our manufacturing sites across Japan, from Hokkaido in the north to Kyushu in the south. We also ship limestone aboard large bulk carriers (60,000-ton class) from the Torigatayama Quarry Complex, which has the largest production output in Japan.

Dolomite is a type of limestone made up mostly of magnesium instead of calcium. Dolomite is also known as dolostone. The chemical formula of dolomite is CaMg(CO3)2, similar to limestone (CaCO3). Nittetsu Mining extracts and processes limestone at KUZUU LIMESTONE AGGREGATE CO., LTD., in Sano City, Tochigi Prefecture, which accounts for more than 80% of the limestone produced in Japan.

Silica rock is a mineral mainly comprised of silicon dioxide (SiO2). Nittetsu Mining handles silica rock extracted in Oita Prefecture and imported silica rock from China. This rock is graded according to customer use and sorted by size before being supplied throughout Japan.