Nonmetallic minerals market is not experiencing best times now: demand catastrophically drops down, carriage tariffs are growing, hryvna and ruble exchange rates are draping down… Looks like development is not possible at all. However, as is well-known Chinese word “crisis” consists of two hieroglyphs – first means “danger” and the second means “possibility”. Eventually any crisis comes to an end and companies should be ready for new round of expansion. Our magazine visited companies who are paying attention on the second hieroglyph, they mutually successfully finished ambitious project on start-up of new up-to-date crushing and screening plant in Zhytomyr region.
CRH (Ireland) is the world leader in building materials. The main business segments are cement, asphalt, concrete and gravel. Gravel for CRH in Ukraine is presented by "Bekhy specialized pit”. Company is located in Korosten district, Zhytomyr region and has good reserves, developed transport infrastructure and qualified personnel. Until recently pit processed rock at the two old crushing and screening plants. Market demand of higher quality gravel, as well as higher volumes, along with stable supply directly indicated the need of modernization of the crushing plant.
Vladimir Shargunov, Purchasing Manager for CRH Ukraine says, "High quality of gravel, flexibility in the release of various fractions, reduced downtime and lower production costs – were the main parameters to approve technical assignment for the new plant. Process and equipment requirements were very high. We have considered several quotations and chose Metso's technology. Firstly, the classic three-stage scheme was complemented by solutions that allow better control of the fractions’ balance; secondly, it is based on the usage of the equipment that has proved its effectiveness - HP cone crushers and TS screens. Thirdly, process guarantee on the basic parameters - productivity and content of the flaky grain was provided".
Commissioning and preparation for commercial operation of new plant is ending now. We asked Sergii Gunko – head of Metso crushing and screening department in Ukraine to tell more about the technology and all the benefits of the plant.
"The new plant that undergoes trials at Bekhy specialized pit, is one of the most, if not the best, innovative complex in Ukraine. Built on the classical scheme of "jaw crusher + cone crusher + cone crusher", it gives the opportunity to produce a wide range of high quality fractions with minimal downtime.
Primary crushing performed by Nordberg С125 jaw crusher which is fed with rock by grizzly feeder, it passes over fine material thereby reduces loads on the crusher and reduces operation expenses. In favor of full-fledged primary screening based on the enhanced version of CVB inclined screen, we refused to use scalpers to separate pit rubbish, as they separate 0-30 mm product. This provides an opportunity to select a smaller class, increasing the yield of valuable product. Pit rubbish storage system is very interesting - it uses radial conveyor, which increases the storage volume by 2-3 times.
Secondary crushing performed by Nordberg НР4 cone crusher which runes in closed cycle. Crusher automation system constantly monitors the level of material in the hopper and crushing chamber and keeps it under the load. This is particularly important, since after the secondary crusher there is a possibility of tacking out of coarse fractions from Nordberg TS4.3 screen. Flexible system of dampers and trays directs flow in a way that the output can be obtained as fractions 20-40, 40-70 and as mixtures of fractions 0-40 or 0-70. Radial Conveyor stores the product, using the maximum available area.
The most important tertiary crushing stage is performed by new model of Nordberg НР6 cone crusher. There are more than ten Nordberg НР4 cone crushers in Ukraine and only one Nordberg НР6. History of this crusher is very interesting – originally it was HP5, but after the first results of its operation, it was understood that its productivity is much higher than it was expected. As a resulted it turned to be HP6, additionally Nordberg HP5 cone crusher was designed. Average flakiness index of the HP6 crusher at Bekhy specialized pit is 11 – 12%. Offered technical parameters on productivity of the fraction 5-20 mm were overfulfilled by 7%.
A number of interesting solutions on the Nordberg TS screens were applied on the stages of intermediate and final screening. Firstly, modular rubber or polyurethane screens are used as screening media at all machines. As is well known, the life of these screens is much longer than of the metal screens. Taking into consideration high abrasiveness of Zhytomyr rocks, the difference in downtimes of the plant will be very noticeable – usage of synthetic screens will ensure higher utilization ratio of Bekhy specialized pit. Secondly, the scheme has the possibility of sending the finished grade 5-20 mm after secondary crushing to the finished product storage. This helps to reduce dropout volume at a sufficient rubble quality level. Third, separate deck is equipped with rectangular cell screens and it can be used for additional screening of flakiness product. Fourth, on the close sizing 0-5, class 2 mm zigzag screens are used which provide qualitative screening even without washing".
New plant is an implementation of great experience of pits in Ukraine. Good primary selection, reduction of dropouts’ volume, gravel of high quality, reduction of downtime for parts replacement - these are the challenges for each pit director in Ukraine. We are confident that with the new plant management of Bekhy specialized pit will have less troubles and more confidence to fulfill their obligations to customers. The correct approach to the investment from the parent company and understanding that a little bigger capital investment will significantly reduce operating costs makes the pit more competitive in the long term. With other necessary components, they can be confident to storm new heights on the market of high-quality aggregates both in Ukraine and abroad.
BETON №1, 2015