Magnezit Group Conducts Construction of Multi-hearth Furnace
The multi-hearth furnace is supplied by Polysius/DE and part of the investment project aimed at increasing capacities by 2,5 times of the Satka Complex for production of dead-burnt magnesia clinkers in the Chelyabinsk region. Annual production capacity of the furnace will amount to 100000 t calcined magnesia. The full cycle of construction and assembling work is scheduled to be completed autumn 2012. The multiple-hearth furnace is intended for primary burning (calcination) of raw magnesite at a processing temperature of 1000–1050 °С. The finished product will be used in the production of dead-burnt magnesia clinker. The new unit ensures production of material with certain characteristics, which considerably reduce the risk of waste production during further technological treatment. The magnesite calcination in a multiple-hearth furnace is an alternative process to magnesite calcination in a rotary kiln and corresponds to the highest world standards of environmental safety. The unit has a diameter of 7,85 m and 32 m in height. The furnace process chamber is shaped as a vertical cylinder with 19 horizontally positioned hearths, dividing the furnace into chambers with various temperature conditions. Material movement from one hearth into another one is ensured by gravity and by a special shaft passing through the furnace with paddles fixed in a certain manner. The furnace is equipped with 40 main gas burners supplied by Hans Hennig/DE and has an automated control system. The whole complex of the multiple-hearth furnace has a very high degree of automation. Furnace assembling has already begun and the bottom hearth, the 19th, has been already installed onto supports. This bottom hearth weights about 28 t and has a length of 8 m. Assembling of all the hearths will be done with the help of a mobile crane with a capacity of 160 t supplied by Liеbherr/DE. Magnesia clinkers and magnesia-based products are now in strong demand both in Russia and beyond its borders. The 1st stage of the Complex for production of dead-burnt magnesia clinker with a capacity of 50000 t/a was commissioned at 5 September 2008. The competitive advantage achieved due to implementation of this project up to now remains unachievable for other refractory manufacturers based in Russia and in the CIS countries. After commissioning of the 2nd stage of the project, including the multiple-hearth furnace, the calcination complex will correspond to the best world analogues production units – singular manufacturing facilities in Australia, Ireland and Netherlands. The investment project for increasing capacity of the Complex up to 13000 t/a for dead-burnt magnesia clinkers production also includes the construction of another unique unit i.e. a high-temperature Polysius shaft kiln with a production capacity of 80000 t/a. By now, the Magnezit Group is finishing the preparation of the documentation project for the construction of this kiln. It is intended for burning of briquetted calcined magnesia. This new kiln will have improved production capacity and has no analogues in the CIS countries. The total volume of investments for expansion of the production capacity of this Complex for the production of dead-burnt magnesia clinkers, i.e. for the construction of a multiple-hearth furnace and a high-temperature shaft kiln exceeds RUB 1,8 billion (6/2012).