The art
of grinding

Welcome

Welcome to Swiss Tower Mills Minerals AG. We are an innovative company in the regrind, fine and ultra-fine grinding industry.



Swiss Tower Mills Minerals AG (STM) was founded in 2012 to introduce the well proven fine grinding technology of industrial minerals to the mining industry. Today more than 200 grinding mills are operating today to grind industrial minerals with truly minimized energy requirements; over 10 units are currently operating in the hard rock mineral processing industry. STM’s technology enables the mining industry to profit from more than 40 years of development and operational experience in fine and ultra-fine grinding.

In the meantime, the HIGmill™ has been accepted by the hard rock mineral processing market. Numerous tests have been successfully performed, both laboratory or on site. STM has received several orders from very small test and pilot mills, up to several large 5 MW HIGmills. A 700 kW HIGmill for a copper concentrate regrind application at the Kevitsa mine in Finland has been commissioned in February 2015 and is operating successfully; both the copper recovery and the copper grade in the final copper concentrate have been increased significantly, where at the same time the nickel grade in the final copper concentrate has been reduced. Other HIGmillsTM are in Operation now in a copper and in a platinum concentrator.

 
 
Experienced Team
with proven track record
in minerals processing

About Us


Contacts


Hanspeter Erb
CEO

Tel: +41 58 590 3502
Cell: +41 79 529 4525
Email: hanspeter.erb@stmminerals.com
Ralf Hesemann
COO

Tel: +41 58 590 3519
Cell: +41 79 369 0085
Email: ralf.hesemann@stmminerals.com
Maarten van de Vijfeijken
Sales

Tel: +41 58 590 3512
Cell: +41 79 593 0804
Email: maarten.vijfeijken@stmminerals.com
Per Thorn
Sales

Tel.: +41 58 590 3501
Cel.: +41 79 251 3012
E-mail: per.thorn@stmminerals.com
Günter Probst
Project Management

Tel: +41 58 590 3507
Cell: +41 79 855 1497
Email: guenter.probst@stmminerals.com
Patricio Huencho
Sales Promoter South America

Tel: +56 2 2946 4383
Cell: +56 9 6678 4707
Email: patricio.huencho@stmminerals.com

Board


Hanspeter Erb
Email: hanspeter.erb@stmminerals.com
Fritz Moser
Email: fritz.moser@stmminerals.com
Bernhard Schupp
Email: bernhard.schupp@stmminerals.com
Robert Lang
Email: robert.lang@stmminerals.com
Kimmo Kontola
Email: kimmo.kontola@outototec.com

Partners & suppliers



In 2012 Swiss Tower Mills Minerals AG and Outotec entered in to an exclusive technology agreement to market STM’s VRM (Vertical Regrind Mill) type mills. The Outotec brand name is HIGmillTM (High Intensity Grinding mill).

Outotec HIGmills »
 

Swiss Tower Mills Minerals AG has an agreement with KMF (Kärntner Maschinen Fabriken) GmbH to manufacture the HIGmills. During the last 40 years KMF has produced more than 200 of these mills for the industrial minerals market. KMF has over 40 years’ experience in manufacturing fine grinding mills for the industrial minerals industry. KMF is ISO 9001 and ISO 14001 certified and holds numerous special certificates for welding and safety.

www.kmf.at »
 
 
More
out of ore

Products

Overview


Declining ore grades and more complex ore bodies lead to a clear trend for fine grinding. Fine grinding technology has already been used for more than half a century in the ceramics, pigment, paint, paper and pharmaceutical industries. The unique grinding technology, which Swiss Tower Mills Minerals AG offers for the mineral processing industries, has been well proven over more than 40 years in the industrial mineral segment: over 200 fine and ultra-fine grinding mills are in operation, with a total installed power of over 300 MW. The largest units in operation have each an installed motor power of 5 MW. Swiss Tower Mills Minerals AG has made this exceptional grinding technology available to the mineral processing industry.

The ceramic grinding beads in the mixing cylinder are put in motion by the grinding rotors which are mounted on the mill shaft. The mill shaft is powered by a motor and gearbox arrangement. The high packing density of the grinding media produces strong friction, which causes efficient grinding of the product. The variable speed of the milling shaft allows for an energy efficient grinding process to reach the required product particle size.
 
The feed material is supplied as a slurry from below by a feed pump. The mineral particles, which become smaller during the grinding process, rise up in the mill cylinder and leave the mill via a natural overflow on top. Gravity supports to retain the grinding beads, which have a higher density than the slurry, in the milling chamber.

The fineness of the final product (slurry) is adjustable through the following factors:
  • Feed rate
  • Slurry concentration
  • Amount of grinding beads
  • Speed of the milling shaft
 

Key Benefits


The HIGmill™ provides the following key benefits:
  • High energy intensity
  • Efficient transfer of energy from the mill shaft into the grinding bed
  • Low required specific grinding efficiency (SGE)
  • Steep particle distribution curve (PSD) without external classification
  • Single pass grinding (no re-circulating loads)
  • High flexibility to handle fluctuating process conditions:
    • Fluctuation in slurry feed rate
    • Fluctuation in slurry particle feed size
    • slurry consistency / ore characteristics
    • required product size
  • Simple flow sheet leads to cost reduction
  • Minimized footprint due to vertical milling arrangement
  • Easy maintenance
  • High availability due to long maintenance intervals
Both CAPEX and OPEX are significantly minimized with this regrind mill technology.
 

HIGmill™ Portfolio


Swiss Tower Mills Minerals AG has established an extensive portfolio of vertical regrind mills, in order to ensure a perfect match between project specific demands and the selected mill type.

Pilot Mill Production Mill
Standard designation for mill HIG 75 HIG 125 HIG 250 HIG 500 HIG 700 HIG 1100 HIG 1600 HIG 2300 HIG 3500 HIG 5000 HIG 6500
Nominal power [kW] 75 125 250 500 700 1100 1600 2300 3500 5000 6500

Installed base



Installed base of HIGmills in industrial minerals (up to 5 MW).



HIGmill™ reference list in hard rock mineral processing

Year Ordered Location Model Mill Power [kW] No. Mills Duty F80 P80
2013 DRC HIG1600 1600 1 Cu Regrind 212 35
2014 South Africa HIG75 75 1 Pt Regrind (Pilot Plant) Various Various
2014 Finland HIG700 700 1 Cu/Ni Rougher Regrind 50 20
2014 Panama HIG5000 5000 3 Cu Regrind 150 35
2014 Chile HIG3500 3500 2 Cu Bulk Rougher Regrind 75 35
2014 Chile HIG500 500 1 Mo Rougher Regrind 50 40
2015 Germany HIG25 25 1 Test mill iron ore laboratory Various Various
2016 Australia HIG5 5 1 CO2 Capture / Mineral Carbonation Various Various
2016 Mexico HIG3500 3500 1 Pyrite Pre-Leach Regrind 130 60
2016 South Africa HIG700 700 1 Pt Fine Grind 60 30
2016 Chile HIG3000 3000 2 Cu Regrind 125 45
2016 Australia HIG500 500 1 Gold Pre-Leach Grind 50 25
2016 Mexico HIG950 950 2 Ultra-Fine Pyrite Pre-leach Grind 40 8
2016 Turkey HIG2650 2650 1 Copper Regrind 82 30
2016 Australia HIG1400 1400 1 Ultra-Fine Copper Regrind 50 10
2016 Argentina HIG75 75 1 Fine Gold-Silver Grind 75 30
2017 Australia HIG800 800 1 Copper Regrind 65 20
2017 Australia HIG3500 3500 1 Sulphide Gold Concentrate 175 10
2017 Spain HIG25 25 1 Copper Regrind Various Various
2017 Australia HIG5 5 1 Various Various Various
2017 South Africa HIG110 110 1 Metspar 150 75
2017 South Africa HIG185 185 1 Acid refloat 75 45
2017 South Africa HIG425 425 1 Acid concentrate 150 75
2017 Canada HIG700 700 1 Gold  170 40
2017 Turkey HIG1100 1100 1 Copper Regrind 38 11
2017 Australia HIG1600 1600 1 Cu/Au regrind 53 20
2018 Mexico HIG1100 1600 1 Au/Ag Tertiary grind 150 50
2018 Mexico HIG1100 1600 1 Au/Ag Tertiary grind 150 50
2018 Ecuador HIG700 700 1 Au regrind 60 45
2018 Botswana HIG1100 1100 1 Cu Concentrate 80 20
2018 Mexico HIG1800 1800 2 Pyrite regrind 80 22
2019 Mexico HIG1600 1600 1 Au/Ag Tertiary grind 150 50
2019 Mexico HIG132 132 1 Pilot mill Various Various
2019 Russia HIG3000 3000 2 Copper regrind 62 25
2019 Brazil HIG2300 2300 1 Copper ball mill duty 300 75
2019 Brazil HIG1600 1600 1 Copper concentrate regrind 71 20
Total Power/Number of
HIGmills in Mineral Processing
70 MW 43      
 
Simple flow sheet
efficient, flexible & single pass

Process

Flow sheet


Typical overall flow sheet



The typical HIGmill™ flow sheet for regrind circuits is simple and straight forward. Regrind feed from the flotation goes to a scalping cyclone. The cyclone overflow (typically 10 – 50%) bypasses the HIGmill™. The cyclone underflow is pumped into the mill, where the target product size, with a steep particle distribution curve, is produced in one pass. Having no re-circulating loads, pumps, piping and mill cylinder volume can be significantly reduced, while achieving a product with a steep particle size distribution curve.
Typical regrind circuit flow sheet

 
 

Advantages


The HIGmill™ provided the following process related advantages:
  • Steep particle distribution curve (PSD) without external classification
  • Single pass grinding (no re-circulating loads)
  • Flexibility to handle conveniently process variables as:
    • Fluctuation of slurry feed rate
    • Fluctuation of particle feed sizes
    • Feed slurry consistency / ore characteristics
    • Required product size
  • Simple flow sheet leads to cost reduction
  • Relative small pumps (no re-circulating loads)
Both CAPEX and OPEX are significantly minimized with this regrind mill technology.
 

Application


The HIGmill™ cover a wide range of applications for fine and ultra-fine grinding, such as:
  • Concentrate regrinding (gold, copper, moly, platinum, lead, zinc, ...)
  • Iron ore fine grinding
  • Tailings regrinding
  • Slag & fly ash grinding for recovery of recyclable metals
 
We are here
to serve the customer

Services

Manufacturing


The HIGmills are designed by Swiss Tower Mills. The main mill components are manufactured by KMF in Villach, Austria. KMF is a leading company specialized in tilting rotary furnaces, mills and grinders, special machinery, plant construction, process engineering and contract manufacturing. KMF has over 40 years’ experience in manufacturing fine grinding mills for the industrial minerals industry. Naturally KMF is ISO 9001 and ISO 14001 certified and holds numerous special certificates for welding and safety.
 
 

Engineering


Swiss Tower Mills Minerals AG has the required know how to provide the necessary engineering services, such as:
  • Finite element modelling and analysis of the separate mill components as well as the complete mill
  • Identification and mitigation of resonance frequency issues
  • Design and build in accordance with project specific seismic requirements
  • Design of all main structural components to withstand the applied dynamic forces as well as calculation of expected lifetime
  • Spare part management support
  • Creation and implementation of the control and protection philosophy for the regrind mill
  • Drive system engineering
 

Maintenance


The partnership with Outotec ensures that end users have access to an established worldwide and state of the art service network.

Outotec: Operations Services »
 

Testing


Swiss Tower Mills Minerals AG and Outotec operate several mobile and stationary test HIGmills units with three different mill sizes and offer these test services to customers globally. The stationary test units are located in Villach, Austria and at Outotec Research Center (ORC) in Pori, Finland. Additionally the portfolio includes the larger HIG75 pilot mill. Base line test work with the HIG5 test mill requires a minimum of 4 kg of dry test material.
On-site testing is possible with the HIG25 containerized mobile test unit or with the HIG75 pilot mill. Additional testing can be performed at ORC. ORC develops metal processing technologies, processes and equipment and its expertise covers the entire processing chain from ore to metal, starting from mineralogical analysis.
 

HIG25 test container

SGA Liebenburg in Germany
 

HIG5 test mill in Austria

HIG5 test mill in South Korea
 
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to read