The 1980s saw the beginnings of a shift in the cement industry. Slowly and steadily, cement producers began to adopt vertical roller mills (VRMs) for cement grinding instead of ball mills. Fast forward to today, and the VRM, with its superior grinding efficiency and low power consumption, is the industry standard. Since FLSmidth’s initial OKä Mill installation in 1982 through to the end of 2018, customers have bought a total of 184 mills.
Raw materials grinding was added to the OK Mill’s résumé in 2017. Following the launch of this flagship VRM, three new OK Raw Mills were sold in 2018.
In 2018, FLSmidth sold 31 new vertical roller mills for all grinding applications. The combined cement grinding capacity of OK Mills from FLSmidth, grew by over 38 % from 2270 t/h in 2017 to 3145 t/h in 2018.
The flexibility of the modular design is a key driver of its success. It uses the same core grinding parts in raw and cement mills, in multiple mill sizes, greatly reducing the capital investment for spare parts in a plant.
Mills for large-capacity plants
FLSmidth has supplied VRMs to 67 countries around the world since the OK Mill was launched in 1982. In the last two years alone, OK Mills have been sold in Indonesia, the Philippines, Algeria, Turkey, United Kingdom, Pakistan, Nigeria, Kenya, Peru, Cuba, India, Nepal, Algeria and Egypt.
Particularly in South Asia and Africa, where large-capacity plants are installed, cement producers choose single big mills to take advantage of the lower installation costs associated with a single mill versus multiple smaller units. Perhaps the most impressive example of this is at Shah Cement in Bangladesh, where an 81-6 OK Mill, one of the world’s largest vertical roller mills for cement grinding, was inaugurated in 2018 – featuring six rollers and a whopping 8.1-m diameter grinding table.
The average grinding capacity per sale of OK Mills for cement grew by almost 10 % from 2017 to 2018 (206 t/h in 2017 to 225 t/h in 2018). FLSmidth has supplied OK Mills with grinding tables ranging between 2.8 m and 8.1 m in diameter. The number one selling mill size is the OK 56-4 Mill, which is right in the middle of the available size range.