About Us


Inspired by his creative idea that the novel and most energy efficient grinding concept for fine and ultrafine grinding of industrial calcium carbonate, as developed by Omya during the second half of the last century, might be successfully applied into non white minerals, Fritz Moser, based on his wide ranging experiences from ABB, secured a long term license in order to found Swiss Tower Mills Minerals AG (STM) in August 2011, together with a small team of experts, in Baden, Switzerland. The vision was clear – to revolutionize and expand this novel technology and apply it to base and precious metals mineral processing.

Numerous test trials with different metal containing minerals proved the milling concept to be quite promising, even in the first large scale applications. However, it became obvious that grinding these more abrasive metal ores, rather than soft calcium carbonate, may lead to short replacement intervals of wear parts. Hence, together with Outotec Oy, as its marketing partner, STM developed and tested a wide variety of novel design features and cutting edge materials, that were disclosed in patents that guaranteed highly competitive replacement intervals, and increased grinding performance.

STM has continued this relationship with Outotec, now merged with Metso, for sales of equipment and services to the worldwide minerals market, with an exclusive partnership arrangement for grinding applications with a product size less than 30µm, Metso market the STM Vertical Regrind Mills (VRMmill™) as HIGmill™

Meanwhile STM has delivered HIGMill’s ™ with an installed power of up to 6.5MW, have established a new state of the art for fine and ultrafine grinding of iron, copper, zinc, gold, molybdenum and platinum minerals in more than 50 projects throughout the global mining market, and proves its milling concept based on a development history of more than 50 years, to continue to be highly energy efficient, sustainable, and unique.

STM further developed its milling concept for coarse grinding to offer a more energy efficient grinding of minerals compared to traditional horizontal ball mills and has a goal to replace ball mills in processing plants of the future. Additionally, STM has expanded the future product range to an incredible 12.5MW installed power.

Weir Minerals recognized the performance of our vertical mills in combination with their Enduron® High Pressure Grinding Roll (HPGR) mills to create the most energy efficient grinding circuits. In 2022, Weir Minerals and STM signed an agreement to market STM VRMmills™ together.

Since the beginning, STM has a close and successful strategic manufacturing partner in KMF Austria, providing excellence in manufacturing quality and reliability, this partnership continues to provide for world class manufacturing and assembly.

STM continues to sell its novel grinding mills and services to the customers of the worldwide minerals market through its partners Metso and Weir Minerals, as well as directly to the global mining market.



Swiss Tower Mills Minerals AG was founded


Outotec (now Metso) exclusive technology agreement


First order received in Chile for QB2 project


Commissioning of Kevitsa mine in Finland
First 5000kW mills in base and precious metals processing sold to Cobre Panama


12 fine grinding mills sold in 6 countries


STM launches novel grinding rotor, increasing performance and wear life


Ironbridge selects STM for 10x 5,000kW secondary and tertiary grinding mills, Cobre Panama mills operational


Freeport McMoRan, Grasberg chose STM for 2x 5500 kW grinding mill, KSP joint company opened


Swiss Tower Mills Minerals Australia Pty Ltd office opened


First coarse grinding mill applications installed and operational, Swiss Tower Mills Minerals Chile SpA office opened