Each non-metal industry company at the planning stage or before production expansion is to decide which operation conception to choose: stationary plant or mobile plant. This issue is even more important because it affects not only crushing and screening processes but also lots of other aspects as drilling, blasting, rock transportation, arrangement of product storages, getting permits and so on.
Both options have advantages and disadvantages, which are often mutually exclusive. For example, a stationary plant is expensive and cannot be moved when necessary to a new site, while it is easy to relocate having mobile plant. On the other hand, in terms of operating costs and crushing process stability mobile plants clearly lose out to stationary plants. Which one to choose? Which way to go?
Metso produced new concept of the crushing and screening line for rubble based on the standard modules of the popular crushers and screens to help in solving of this issue. Each module on its structure has main machine, auxiliary equipment, electrical cabinet, maintenance platforms, stairs and handrails. Unlike stationary equipment, installation of modules doesn’t require capital bases and they can be installed on prepared solid ground. This feature gives the possibility to transfer modular plant to a new pit. The modules themselves are interconnected by conveyors and form a complete crushing and screening plant. There is a great variety of plant configurations – starting from the single-stage crushing plant for coarse fraction 40-70 mm to 5-10 mm and 10-20 to the three-stage crushing plant for complex processing of the blasted rock into high-quality gravel. All plants are equipped with automatic systems, which greatly simplifies production process control.
Modular plant promptly gained popularity on emerging markets such as India, China, Brazil and CIS countries because it combines advantages of stationary crushing plant and mobile crushing plant. The first modular plant has been installed in Ukraine this year
It is specific that technological schemes of modular and stationary plants are very often identical: the whole set of equipment, including intermediate storage hoppers is identical. This means that the productivity and product quality on a modular plant will be the same as on the stationary. As for crushing products, plants can produce full spectrum of the fractions for the production of concrete or asphalt. There is always a possibility to select pit garbage at the primary stage. Composite products 0-40 or 0-70 mm can be made using tray system at screens unload. This requires only a gate turn to send additional flow to the conveyer.
As for the quality of the product, it is also high, because the scheme is built according to the canons of the production of cube-shaped rubble: uniform feed, crushers work under the load, material paths three crushing stages, crushers operate at high eccentricity. For example, new plant in Zhytomyr region operates two jaw and cone crusher Nordberg HP. There is a hopper before each cone crusher to ensure uniform feed of material and work under the load, this provides permanent crushing in the layer, and thus - high quality of rubble.
Modular plants are the best choice for small and medium pits with average output for the rubble – 400-600 thousand tons per year. Capital expenditures in comparison with the stationary plant is much lower, terms of delivery and installation is shorter, but the customer will have exactly the same performance and quality. Modular plants will also be of interest to companies that implement construction projects for a period of one to three years, as it is more profitable than mobile equipment that is "famous" for its high operating costs. Modular plants will prepare a mixture of the roadway, crush coarse fraction into small with high cubicity, and recycle waste concrete or asphalt.
The modular plant, as an investment, also has a number of advantages: it is easy to reconfigure it for different flow diagrams, it can be moved, it can be long-term leased. Eventually it is always possible to sell it, which can not be done with a stationary plant, because it is walled into concrete foundations.
Due to typical modules, plant layout does not require special engineering, which significantly reduces the time of manufacturing and delivery, as well as the total cost of the crushing and screening line. The first modular plant began its work in Ukraine, and easily performed all declared parameters of productivity and rubble quality. We are confident that many pits will appreciate this concept, due to its flexibility, cost and high quality of equipment, which brand Metso is famous for.
Performance comparison of the three-stage modular, stationary and mobile plants.
Feed rate, t/h
Produced fractions, mm
5-10, 10-20, 5-20, 20-40, 40-70, 0-40
5-10, 10-20, 5-20, 20-40, 40-70, 0-40
5-10, 10-20, 20-40, 0-40
Availability of intermediate hoppers
Possibility to relocate
Average term of project implementation, month
BETON №4, 2013