Intelligent, energy-efficient, continuous crushing

HAZEMAG, a global supplier of equipment solutions for the processing and beneficiation of raw materials in the cement, aggregate, mining and recycling industry, supplied one of the most advanced, and state-of the art crushers to the Lhoist Group. Within the framework of a “retrofit project”, a jaw crusher was exchanged for a new HAZEMAG Primary Sizer HCS 1020 at the French lime works “Dugny”. Focal to the project was the optimization of the main crushing process.

 

With this new crusher the HAZEMAG design engineers succeeded in increasing the production output by more than 20 % and significantly improved the grain shape of the final product, as requested by the customer. The project planning was perfectly coordinated and downtime during the conversion of the crushing plant was kept to a minimum, with just the adaption of the existing steelwork to allow the installation of the new crusher.

 

With a roll diameter of 1000 mm and a roll length of 2000 mm the new HAZEMAG Sizer HCS 1020 can achieve, downstream permitting, an average throughput rate of 800 t/h, which is double the output of the original jaw crusher. Even with a larger feed material of the medium-hard limestone, the HAZEMAG Sizer HCS 1020 succeeds in crushing the material down from 1200 mm to 97 % < 300 mm without loss of capacity. This was unimaginable with the old jaw crusher, however, it can be achieved with the intelligent and patented technology of the HAZEMAG Sizer. The HAZEMAG engineers also succeeded in integra­ting the new HAZEMAG Sizer into the existing crushing plant without having to carry out larger adaptions or adding expensive civils.

 

The LHoist Group ranks among the world’s leading manufacturers of limestone products and is constantly working to optimize production streams. Hence, after consulting with HAZEMAG, they decided in favour of a complete system change, from traditional jaw crusher to “Sizer technology”. The main challenge for HAZEMAG, was not only to increase the capacity of the plant but also to optimize the grain shape of the limestone product.

 

The following problems were resolved following the reorganisation of the crushing plant:

Limestone with a size of less than 30 mm is not suitable for the lime burning process in a shaft furnace, so the fines are screened out which increases the handling costs. Hence, with the introduction of the sizer, and reducing the fines by some percentage points provides considerable cost savings.

On the other hand, the oversized material is also problematic because of its physical size or its quantity, and can result in overloading or jamming of the downstream process.

 

With the introduction of the HAZEMAG Sizer HCS 1020 both problems were addressed and resolved satisfactorily. The quantity of fines in the finished product was reduced by 3 % and the oversize was reduced so as to be more manageable. The overall result of the improved feed grading reduced energy costs during the calcination process in the shaft furnace.

 

Conclusion

This “retrofit project” utilising the HAZEMAG HCS 1020 Sizer turned out to be the “optimum solution” for our French customer. The compact construction of the HCS 1020 made handling during the transport, assembly, and commissioning process trouble-free and resulted in a very short installation period without noteworthy downtime. Also, an important point to note was a considerable improvement in safety aspects whilst maintenance is carried out on the new sizer. The numerous, arduous and frequently risky maintenance tasks carried out by the site fitters to clear the blocked jaw crusher and processes downstream have virtually been eliminated following the integration of the HCS 1020 Sizer.

 

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