Development of Technology for Separating Low Grade Coals from Raw Coals by Fluidized Bed of Dry Heavy Medium.

The concentration of low grade iron ore resources was evaluated by washing and reduction. The advanced concentration methods for low grade limonite and hematite iron ores of South Eastern Anatolian resources required such specific methods. The followed column flotation and magnetic separation, microwave radiated reduction of hematite slime and limonite sand orewere investigated on potential reducing treatment. The bubling fluidized bed allows more time to the heat radiation and conduction for reducing to the resistive ıron compounds. Furthermore, heavy limonite and iron oxide allowed sufficient intimate contact coal and biomass through surface pores in the bubbling fluidized bed furnace due to more pyrolysis gas desorption. Bubbling bath porosity decreased by temperature decrease. This research was included reduction in microwave of poor hematite and limonite ores in the microwave ovens, but through smaller tubing flows as sintering shaft plants following column flotation and scavangering operation. Two principle stages could still manage prospective pre reduction granule and pellet production in new sintering plants. There is a lack of energy side which one can produce reduced iron ore in advanced technology plants worldwide. However, for the low grade iron ores such as limonite and sideritic iron ores it was thought that microwave reduction technique was assumed that this could cut energy consumption in the metallurgy plants.

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Lab-scale investigation of Middle-Bosnia coals to achieve high-efficient and clean combustion technology

Thermal Science ◽

10.2298/tsci1403875s ◽

2014 ◽

Vol 18 (3) ◽

pp. 875-888 ◽

Cited By ~ 3

Author(s):

Izet Smajevic ◽

Nihad Hodzic ◽

Anes Kazagic

Keyword(s):

Power Plant ◽

Fluidized Bed ◽

Environmental Indicators ◽

Low Grade ◽

Plant Design ◽

Fluidized Bed Combustion ◽

High Efficient ◽

Combustion Technology ◽

Boiler Design ◽

Clean Combustion

This paper describes full lab-scale investigation of Middle-Bosnia coals launched to support selection an appropriate combustion technology and to support optimization of the boiler design. Tested mix of Middle-Bosnia brown coals is projected coal for new co-generation power plant Kakanj Unit 8 (300-450 MWe), EP B&H electricity utility. The basic coal blend consisting of the coals Kakanj: Breza: Zenica at approximate mass ratio of 70:20:10 is low grade brown coal with very high percentage of ash - over 40%. Testing that coal in circulated fluidized bed combustion technique, performed at Ruhr-University Bohum and Doosan Lentjes GmbH, has shown its inconveniency for fluidized bed combustion technology, primarily due to the agglomeration problems. Tests of these coals in PFC (pulverized fuel combustion) technology have been performed in referent laboratory at Faculty of Mechanical Engineering of Sarajevo University, on a lab-scale PFC furnace, to provide reliable data for further analysis. The PFC tests results are fitted well with previously obtained results of the burning similar Bosnian coal blends in the PFC dry bottom furnace technique. Combination of the coals shares, the process temperature and the air combustion distribution for the lowest NOx and SO2 emissions was found in this work, provided that combustion efficiency and CO emissions are within very strict criteria, considering specific settlement of lab-scale furnace. Sustainability assessment based on calculation economic and environmental indicators, in combination with Low Cost Planning method, is used for optimization the power plant design. The results of the full lab-scale investigation will help in selection optimal Boiler design, to achieve sustainable energy system with high-efficient and clean combustion technology applied for given coals.

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