Our Grolls™ Technology

One Step Ahead

Our GRolls™ Technology

The Gyratory Rolls Crusher (GRolls™) is a compression based particle size reduction device, designed to generate fine and ultra-fine products from coarse feeds, by simultaneously applying pulsed compression and shear forces to a packed particle bed.  The breakage mechanisms initiated by these forces include impact breakage, inter-particle compression, induced tensile failure and particle shear forces generated by a gyrating roll.

The GRolls™ consists of a “v” profiled main rotating drive roll and an opposing gyratory roll with an intermeshing “v” profile.  The main rotating drive roll is driven through a gearbox, while the gyratory roll is mounted on a driven shaft with an eccentric off set to generate the gyratory motion.  The gyratory roll is engaged and free to rotate in mesh with the main driven roll as feed enters the crusher.  The gyratory motion generates a high frequency pulsing action which initiates particle breakage.

The GRolls™ can operate in both dry or wet process conditions whilst reducing coarse feed into fine and ultra fine particle sizes with low recirculation rates.

The concept of the GRolls™ is subject of an international patent application PCT/AU2021/051052 by Applicant CBSM Mining Services Pty Ltd, filed on 10 September 2021. A national phase entry request for Australia was filed on 18 March 2022. A trade mark application was submitted on 18 March 2022 for “GRolls™”.


Testing Results

CBSM has conducted laboratory scale testing of the laboratory scale GRolls™ on silica sand, slag, limestone and magnetite ore feed materials under different configurations which has demonstrated impressive size reductions for the range of dry feed materials. The results of the GRolls™ preliminary dry testing program are summarized in the table below.

Note:   NSE = Net Specific Energy, SSE = Size-Specific Energy and Wio = Bond operating work index.

The initial energy consumption test results are favorable with competitor equipment, such as the High Pressure Grinding Rolls (HPGR) and Super Fine Crusher (SFC) reported in Baawuah et al (2020).  Even though the GRolls™ reported higher Net Specific Energy (NSE, kWh/t) consumption for all feed materials, the very large size reductions (RR80) of the GRolls™ generates nearly twice the fines content (%<75µm) which results in significantly lower recirculation loads and more energy efficient comminution as presented in lower Bond operating work index (Wi) values.  When considering the energy consumption of air classification (NSE 4-7 kWh/t), the lower recirculation loads of the GRolls™ will result in lower overall energy consumption for tertiary and quaternary dry comminution circuits.

CBSM conducted wet feed materials testing which confirmed the applicability of the GRolls™ technology to wet mining processes.  Minus 3 mm limestone was fed as a 33-34% solids (w/w) slurry into the GRolls™ to simulate a mining wet process circuit requiring tertiary/quaternary regrind.  The test conditions included processing the same feed material dry and as a slurry, with results showing similar impressive size reductions for the slurry to dry feed material.

Dry Testing

Wet testing

Additional GRolls™ test information is presented in our latest company brochure which is available on request to info@cbsmmining.au

The GRolls™ is a compression-based particle size reduction device, designed to generate fine to ultra-fine products from coarse feeds.  The main competitors to the GRolls™ are HPGR and Vertical Rolls Mills (VRM) for dry and stirred mills for wet flow sheets.  The GRolls™ features a gyrating roll which simultaneously applies pulsed compression and shear forces to the packed particle bed, whereas the HPGR and VRM’s relies solely on inter-particle compression breakage within the particle bed passing between moving rollers, and stirred mills are reliant on particle attrition from gravity-induced and fluidized technologies. The GRolls™ technology encourages intergranular breakage, with the potential of exposing value surfaces more readily.

Higher generation of fines per single pass of material results in lower recirculation loads, less air classification and lower power consumption per tonne of product.

The capacity of the GRolls™ to effectively operate wet as well as dry differentiates it from HPGR’s and VRM’s, both do not tolerate feed moisture. All other grinding equipment are wet and are not suitable for dry processing unlike the GRolls™.

Our GRolls™ can operate dry and achieve similar energy and media savings to HPGR’s and VRM’s

Our GRolls™ can operate wet – HPGR’s and VRM’s can’t

Our GRolls™ could operate in wet regrind circuits without media and could reprocess tailings – HPGR’s, VRM’s and stirred mills can’t

CBSM believes the GRolls™ meets market demand for comminution equipment that can operate wet or dry, with low energy consumption, no media, produce targeted fines with low recirculation loads, be adaptable, scalable, modular and transferrable to exploration, feasibility through to operational stages of mining and cement process plants.

The GRolls™ Advantage

Slow motion video of dry then wet testing