World Cement invited industry leaders to share their thoughts on a range of grinding and milling-related topics. Contributions come from: FIVES FCB, Gebr. Pfeiffer, and thyssenkrupp Industrial Solutions.
1) In our increasingly climate-conscious world, emissions reduction remains a key goal for the cement industry. What steps can be taken to reduce the environmental impact of cement grinding operations?
As well the consideration of production costs and carbon footprints, one key issue is energy consumption. For reference, the grinding process represents a significant part of a cement plant’s electrical demand, in the range of 50 – 70% of the total integrated plant’s needs. Therefore, limiting grinding power demand is a major industry focus.
The end-product evolution is another key issue to address, with respect to the expansion of the cement additives range and cement/clinker ratio, as well as the emergence of ultra-fine products in the cement industry. It appears then that the solutions are to be found in versatile technologies, with low-energy consumption, and the capability to adapt to a wide range of raw materials, which come with their own constraints such as grain size variation, moisture content, grindability, etc.
The FCB Horomill® grinding system can help provide a solution to these challenges, offering low energy consumption and high flexibility and end-product quality for an optimised cement/clinker ratio.
Sustainability is one of the most important challenges facing cement production, which is responsible for 8% of global carbon emissions – the dependence on fossil fuels must be reduced. In the area of material comminution, we are constantly optimising our systems to save raw materials and energy, and thus reduce emissions. Especially in the recent past, we have been able to increase the already high power density of our MVR mills by a further 10% and also drastically reduce the water requirement and pressure losses in the overall system, to name just a few examples. And we are determined to continue on this path of constant improvement.
On the way to achieving climate neutrality for cement plants, there are many pieces of the mosaic that only together form a complete pattern. This starts with low-CO2 raw materials, alternative fuels, kilns with carbon capture technology, reduction of clinker content, energy-efficient grinding, and many other aspects, such as transport of the cements.
The cement grinding process will be further optimised and become significantly more environmentally friendly. The trend toward using clinker substitutes will also continue. Taking all these aspects into account, mill designers must ensure that energy-saving comminution is possible and is further improved.
thyssenkrupp Industrial Solutions
Cement producers can apply the following measures in order to reduce the environmental impact of their cement grinding plants: Reduction of the clinker factor by shifting the production towards cement types with the maximum possible proportions of constituents. By increasing the amount of fly ash, limestone, pozzolana or granulated blast-furnace slag in the final cement product, the clinker factor and consequently the required heat consumption per ton of cement as well as all emissions (CO2, NOx, SO2, TOC, etc.) caused by the clinker burning process are significantly reduced.
Along with the increasing demand for low clinker cements or high early strength cement types, the installation of the polysius® booster mill is a highly energy-efficient solution for achieving the necessary cement quality even at existing cement grinding plants. It is a horizontal agitated bead mill based on a modular and very compact design, which is advantageous for very fine grinding of cementitious materials or constituents. As the polysius booster mill releases a very high energy density, it is well suited for the production of high-performance cements or shifting the portfolio to lower clinker cement types and simultaneously for reducing the emissions.
Depending on the specific customer needs, the cement grinding plant installation comprising a high-pressure grinding roll polycom® or a vertical roller mill quadropol® in conjunction with a sepol® separator technology offers the lowest specific power consumption. These best available grinding technologies not only help the cement industry to save OPEX costs, but also to reduce its emissions, especially the CO2 footprint and the exhaust gases originating from the hot gas generator of the cement grinding plant.
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Read the article online at: https://www.worldcement.com/special-reports/18022022/world-cement-grinding-milling-qa/