IPCC TECHNOLOGY
RWE on green mining
Paul Moore caught up with RWE Technology International Head of Mining & Materials Handling , Arie-Johann Heiertz on the future of IPCC
Q Is the general trend towards zero emissions 2030 and 2050 making IPCC a more economic option in terms of initial cost , especially when compared to switching a whole mobile fleet to battery and / or trolley operation ? A The trend in carbon reduction and electrification of mines is definitely pushing the IPCC and continuous mining topic . Initially higher capex of the IPCC systems is compensated also by the higher cost of electric mobile equipment . Also , when many countries and large mine operations are still very dominated in their thinking by truck systems , the truck technology providers are still not able to offer feasible , fully-electrified mining systems . Until now , most of the solutions seem to be on a research and engineering level without reliable experience . Trolley assist offers great potential but also requires intensive road maintenance and additional capex . The big advantage of IPCC technology is that has been proven over many decades and very experienced OEMs and consultants are in the market to help clients realise successful green mining projects .
Q While a greenfield mine is the ideal for IPCC application , what can IPCC bring to brownfield projects ? Is even a truck fleet reduction now attractive ? A As a consultant we are always looking for the most feasible option for our clients and of course pure IPCC can ’ t be always the right way . Also , while greenfield mining operations offer great potential for an optimised IPCC implementation , IPCC can be also successfully applied in brownfield operations . Here the biggest potential in energy savings and application of electric mining systems is with IPCC and conquering elevation . Here IPCC conveyors have a much lower initial energy consumption and materials can be moved in a much more economic way . In many operations where we have been involved it is very feasible to still have a truck fleet serving a semi-mobile crushing station on short haulage distances and even surfaces but moving the material on higher lifts out of the pit with conveyor belts . lines is done by one person in the mine control room . Also , when these systems require maintenance they are very predictable and easy to monitor . In combination with integrated maintenance planning systems , maintenance is mostly done in the shadow of other events to guarantee high annual effective operating times .
Q Aside from being electric is IPCC also greener for other reasons including less dust ( and so less water use ), ability to use more power regeneration ? A What we are seeing at client projects is that IPCC has much less dust and noise emissions than truck haulage . By the application of conveyor belts , very cost intensive road grading , wetting of the roads or the use of polymers can be avoided . The haulage is shifted to the conveyor belt where dust can be reduced very efficiently with proven technology at certain spots . This offers the potential to operate large scale mining operations even closer to densely populated areas . As conveyor lines are operated on inclines in a downhill direction they can even produce energy by generative braking . Depending on the project , this can turn the mine site into an energy plus energy operation .
Q As interest in dry stacked tailings increases , is this another growing area in application of conveyor technology in mines ? A In the last three years we have seen major interest in dry stacking technology using conveyor belts and stacker systems and we have done several studies in that field . Based on the major incidents with tailing deposits in the past the operators are tending to move away from wet disposal more towards dry stacking with stable build-up of dump sites . Wet tailings are dewatered by a filter press system and the water can be recycled and brought back into the process . This is also very interesting for sites with sparse water resources such as those in the Andes .
Q Is IPCC also a more attractive option for operators aiming at fully autonomous mines as the relative maintenance aspect is still less than maintaining a truck fleet ? Has conveyor maintenance also become more preventative & predictive ? A IPCC offers by its nature great potential for automation . Just an example , in one of our mines we are operating 130 km of belt conveyors with capacitiy of 38,000 t / h . The complete operation of these conveyor
Graph showing the vastly reduced energy consumption of conveyors versus trucks in mining of the technical and economic advantages .” Three profiles summarise the main DSI Flying Sandwich proposals , exemplify the broader technology and reveal the special advantages when spanning long distances .
FS1 is a crushed stone lowering system . A French mountainside quarry needed to lower the crushed rock product to storage at the plant site . The suspended Flying Sandwich offered the optimal solution suspending the high angle conveyor structure from the quarry ’ s operating level down to the coarse rock storage pile . The conveying rate is modest , only 500 t / h , but the span is significant exceeding 300 m . The system is decisively regenerative feeding power back into the grid when operating under load .
FS2 featured both the DSI Flying Sandwich technology as well as the patented DSI Adder Snake technology . Conveying coal from the plant to the dock , the 2,000 mm wide conventional adder belt , with its bulk load , enters the 2,400 mm wide Belt Sandwich at the top of a cliff then is lowered in the sandwich at a high angle of 43 degrees down to the shore level where the bulk is discharged onto a dock conveyor . The adder belt separates from the Sandwich conveyor ’ s bottom belt , at the discharge , for an independent return to its tail loading point . This system features a very high volumetric rate of 4,667 m 3 / h . With its modest span over the cliff , this
system does not offer the distinct Flying Sandwich advantage of FS1 and FS3 as the savings of the light wire rope structure are offset by the terminal anchor stations . This system is just as well served by a conventional truss spanning structure with one intermediate support bent .
FS3 , depicted in the attached graphic , elevates primary crushed copper ore from the in-pit crusher to the surface , 261 m . A high conveying rate of 5,514 t / h is achieved with 2,000 mm wide belts running at 4.5 m / s . The Flying Sandwich wire rope suspension is able to span over many benches , minimising the number of support
towers .
IM
48 International Mining | APRIL 2022