The raw material (limestone, clay, sand and iron ore) is primarily gained from the quarries via blasting. The raw material is then broken down into crushed rock by crushers (lime/marl crushers) and transported to the cement factory. All of the raw materials are then milled together and dried in the ball mill. The raw mix which is produced from this process is then burned into so called clinkers in a rotary kiln (at approx. 1450 °C). Finally the material will then be cooled down in a cooler to a temperature of under 200 °C. Before being transported to the ball mill and before the milling stage, the large clinker parts will be broken down by a clinker crusher hammer. The generated granules are then milled together with gypsum or anhydrite in the ball mill in order to produce the finished product – the cement. The shipment of the cement takes place either loose or it will be filled into bags.


Circular cycle with aramid V-belts
Immense drum mills are used in order to break down the raw materials. The drives move a volumetric capacity of between 40,000 and 160,000 litres. Optibelt V-belts with aramid tension cords were recommended, that are now used by SACMI in order to ideally meet the requirements, to increase the reliability and to minimise the stretching. On each side of the drive, 32 Optibelt KR V-belts in the 8V 4500/11430 mm size are used. As of that point, SACMI has also been using Optibelt CAP calculation program for the design and calculation of drives. In addition to this, the Italian Company has also been using the TT frequency tension tester in order to inspect the tension of V-belts and Kraftbands.

The belts have been found …
In their 50 production facilities worldwide, Metso Minerals manufactures systems and machines that are sold in over 100 countries via sales offices. Going into detail, Metso Minerals produces – amongst other products – mobile crushing plants for commission processing companies, stone crushing firms, mining company as well as for industry sectors. According to Tero Majuri, development engineer at Metso Minerals: “The Optibelt RED POWER II products are the first choice when looking for appropriate belts.” Due to the fact that high power drives are used during the crushing and milling phases, this means that accordingly top-quality belts are also required. “In RED POWER II from Optibelt, we have found the best belts for our new generation of impact crusher and jaw crushing drives.”


Optibelt V-belts in use
One of the largest stone crushing systems in Europe can be found in the town of Slite, which is located on the Swedish island of Gotland, located in the Baltic Sea – 90 kilometres away from the mainland. It is on this island that the Swedish Company Firma Cementa, a Swedish subsidiary of Heidelberg Cement operates huge systems for the production of cement. Today 64 Optibelt-developed S=C PLUS V-belts drive the Swedish stone crushing system. In particular, the 8V 5230/13280 mm size of Optibelt S=C PLUS is used on site here which ensures that Cementa can produce 2,000 tonnes of stone per hour.


RED POWER II in a cement factory in Great Britain
Deployment in the most difficult of conditions
During a visit to the Tarmac Company in Derbyshire, Alwin Townsend, the Drive Specialist from Optibelt UK explained to the engineer, Colin Higton the remaining last details of the drive optimisation with the RED POWER II maintenance-free high performance V-belts. Today, Tarmac exclusively uses Optibelt quality belts in all of their production machines. Previously, the conventional V-belts or kraftbands had to be replaced on a regular basis. After the conversion to the RED POWER II maintenance-free high performance V-belts, these problems have now been rectified. These maintenance-free V-belts have now been running for more than 17 months – without retensioning and without additional maintenance work. This specific drive of a stone crusher runs for 60 hours per week and without any problems whatsoever according to the responsible Tarmac engineer, Colin Higton. Four units of Optibelt RED POWER II S=C PLUS V-belts in the SPC section with a length of 5,000 mm were selected.