Effects and impacts of components of coal handling system on coke quality and yield of coke plants S. Steinbach, R. Neuwirth, Dr. R. Kim, ThyssenKrupp Industrial Solutions AG (TKIS), Germany

Motivation Increased requirements for the quality of coke A well designed coal handling system helps to improve the coke quality and to reduce the purchasing costs for coal at the same time 2 Simon Steinbach ThyssenKrupp Industrial Solutions AG

3 Simon Steinbach ThyssenKrupp Industrial Solutions AG Influencing Factors Grain size distribution Coal moisture Additives Summary Plant Layout Blend crushing concept Selective crushing concept Recommendations Selective screening and crushing Coal moisture controle Overview

Influencing Factors: Grain size distribution 1 normal raw coal has 30% ~ 50% of grain size < 3 mm the caking ability of coal decreases when the fraction below 0.2 mm is increased Separate grain size of 4 ~ 6mm by screening before crushing to reduce the fraction below 0.2 mm 4 Typical coal size distribution Simon Steinbach ThyssenKrupp Industrial Solutions AG

5 Simon Steinbach ThyssenKrupp Industrial Solutions AG Ideal grain size distribution size target ideal <10 mm 100% 100% < 3 mm 80~90% 100% < 0.5 mm 34~40% 34% *Simons W., Rubrecht E.: Optimaler Körnungsaufbau von Kokskohle, Essen, Germany, 1965 * Influencing Factors: Grain size distribution 2

6 Simon Steinbach ThyssenKrupp Industrial Solutions AG GRAIN SIZE PERCENTAGE GRAIN SIZE *Simons W., Rubrecht E.: Optimaler Körnungsaufbau von Kokskohle, Essen, Germany, 1965 The higher the amount of small particles, the lower the bulk density The bulk density influences the coke strength (M10 and M40) Influencing Factors: Grain size distribution 3

Influencing Factors: Coal moisture 1 7 Simon Steinbach ThyssenKrupp Industrial Solutions AG Coal moisture control plants (CMCP) are common practice to control bulk density and reducing heating costs Usual technologies are drum and fluidized drying *Laske H.: Untersuchungsverfahren zur Charakterisierung fester Brennstoffe, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, Germany, 1961 *

Influencing Factors: Coal moisture 2 8 Simon Steinbach ThyssenKrupp Industrial Solutions AG Moisture control is recommended to stabilize to coking conditions Optimum wall pressure can be achieved at 6% to 9% moisture content *Deutsche Montan Technologie GmbH: Improved energy efficiency and coking process operation and control, Bulk density and internal gas pressure in large volume coke ovens, Germany, internal report *

Influencing Factors: Additives 9 0.1% ~ 0.5% of oil addition to the coal mixture, advantages: Simon Steinbach ThyssenKrupp Industrial Solutions AG Increase of the bulk density without increasing the wall pressure Flow of the charged coal characteristics are getting better Reduces carry over Less spillage coal amount Overheating of the gas collecting space can be avoided

10 Simon Steinbach ThyssenKrupp Industrial Solutions AG Overview Influencing Factors Grain size distribution Coal moisture Additives Summary Plant Layout Blend crushing concept Selective crushing concept Recommendations Selective screening and crushing Coal moisture controle

Plant Layout: Blend crushing concept Problems: hard coals are not crushed sufficiently soft coals are crushed to an extremely fine grain size 11 Simon Steinbach ThyssenKrupp Industrial Solutions COAL TOWER BLENDING BINSCRUSHER

Plant Layout: Selective crushing concept Profit: Control of grain size, moisture and additives leads to stable coking conditions and a better coke quality 12 Simon Steinbach ThyssenKrupp Industrial Solutions DRYERBLENDING BINSCRUSHERMIXERCOAL TOWERSURGE BINSCREEN

Overview 13 Simon Steinbach ThyssenKrupp Industrial Solutions AG Influencing Factors Grain size distribution Coal moisture Additives Summary Plant Layout Blend crushing concept Selective crushing concept Recommendations Selective screening and crushing Coal moisture controle

Selective crushing of each individual coal grade Hard coking coals → coarse crushing Hard coking coals + high swelling index→ fine crushing Softer coals → fine crushing Particle size (<0.1 mm) → graphite deposits → carry-over Recommendations for coal handling plants 14 Simon Steinbach ThyssenKrupp Industrial Solutions AG

Fine grain >40% oiling →(0.1% ~ 0.5%) is advisable. Pre-screening Drying of coal to a constant moisture level Combination of pneumatic classifying and drying upstream crushing. Recommendations for coal handling plants 15 Simon Steinbach ThyssenKrupp Industrial Solutions AG

Overview 16 Simon Steinbach ThyssenKrupp Industrial Solutions AG Influencing Factors Grain size distribution Coal moisture Additives Summary Plant Layout Blend crushing concept Selective crushing concept Recommendations Selective screening and crushing Coal moisture controle

A well designed coal handling plant including: Pre-separation of fine particles before crushing Selective crushing of each coal type Coal moisture control Mixing equipment for additives Allows for: Use of increased portion of low-ranked coking coals Reduction of cost for coal Increase of coke quality Improvement of coking conditions & battery life time Summary 17 Simon Steinbach ThyssenKrupp Industrial Solutions AG

18 Any questions? For further information contact us Thank you for your attention! Simon Steinbach ThyssenKrupp Industrial Solutions AG