Jorge Madias

Mariano de Cordova

metallon, San Nicolas, Argentina

A Review on Stamped Charging of Coals

Content

Introduction

Equipment and Operation

Blend Design and Coke Quality

Recent Research

Conclusions

Introduction

Drivers for this review Start-up of a pilot coke oven

with stamped charging facility at

a steel plant in Peru, with

unexpected results

Dramatic expansion of stamped charging capacity in China:

more than 100 Mtpa of installed

capacity (Dr. Q. Meng, ICSTI

2012)

Introduction

PCI calls for higher coke quality

Coking coal price volatility calls for use of poorly coking coals

One of the answers has been stamped charging

Introducing the coal blend previously ground within a steel box, as successive layers that are

rammed mechanically

The higher the density, the higher the coke quality (mostly for high volatile blends)

Introduction

Developed in Silesia and Poland in the

early XX century

Extended to East and West Europe Germany

France

UK

Czech Republic

Ukraine

Introduction

1978 First 6 m high cake, after long R&D effort

(Feuerfesten Coke Plant,

Germany)

1984 First 6 m high coke stamp charged batteries

(ZKS, Vlklingen) by Didier

and Saarberg Interplan

1989 Battery #7 in Tata Steel

1995-2013 Expansion in China and India

Introduction

Some coke plants with stamped charging Company Location Country Mta Year Builder Oven type ZKS Vlklingen Germany 1.3 2010 (#3)

2012 (#1) Paul Wurth-Saarberg Conventional

ISD Alchevsk Coking Plant Alchevsk Ukraine 2.0 1993/2006 Azovintex-VeCon Conventional Shanxi Changzhi Changzhi China 1.5 MEPC Conventional Shanxi Zhonghua Dali Village China 1.2 SPDCI Heat-recovery Zhongmei Jingda Huian China SPDCI Heat-recovery Jincheng Qinhe Qinhe China SPDCI Heat-recovery Shanxi Sanjia Jiexiu City China SPDCI Heat-recovery Shanxi Luxin Energy Group Shanxi Prov. China SPDCI Heat-recovery Xinjiang International Urumqi China SPDCI Heat-recovery Jiangsu Zhuxi Activated C. Liyang City China 0.75 SPCDI Heat-recovery Shanxi Fenyang Longquan Fenyang C. China 0.4 SPCDI Heat-recovery Hunan Loudi Xinxing Loudi China 0.6 SPCDI Heat-recovery Qingdao Steel Qingdao China 0.6 1995 Saarberg Conventional Taiyuan Gangyuan Donggaobai China 0.4 SPCDI Heat-recovery Xinggao Coking Group Gaoping China 1.0 2000

2008 SPCDI

FLSmidth Koch Heat-recovery Conventional

Tata Steel Jamshedpur India 2.0 1989/2000 Conventional Sesa Goa Amona India 0.28 Sesa Goa Non-recovery Bla Coke Arambhada India 0.25 Bla-VeCon Non-recovery JSW Steel Bellary India 1.2 Sesa Goa-VeCon Heat-recovery JSW Steel Bellary India 1.5 2008 Sinosteel Conventional JSL India 0.42 Sinosteel Heat-recovery JSPL Raigahr India 0.8 2008-2013 Sinosteel Heat-recovery SISCOL Tamil Nadu India 0.4 2007 Sinosteel Heat-recovery Lanco Ind. Ltd. Rachagunneri India 012 2005 Dasgupta-MEPC Heat-recovery Hoogly Met Coke & Power Haldia India 1.6 MEPC Heat-recovery TK-CSA Santa Cruz Brazil 2.0 2010 Sinosteel Heat-recovery

Equipment & Operation

Stamping equipment

Location Stationary (i.e. in a building below the coal tower)

In a stamping/charging/pushing machine

Densification Ramming (several layers)

Vibration (as a complement, for horizontal ovens)

Cake properties Densification

Mechanical properties

Equipment & Operation

Vertical stamping

Equipment & Operation

Horizontal stamping

Equipment & Operation

Cake preparation

Densification Required by the coking process, for coke quality

Influenced by Moisture

Grain size

Coal properties

Stamping energy

Mechanical properties Required to handle cake (critical for vertical ovens)

Compressive strength, shear strength

Favored by densification (and additives)

Equipment & Operation

Influence of moisture on cake density

Equipment & Operation

Influence of stamping energy on cake density

Equipment & Operation

Influence of moisture and stamping energy

on compressive and

shear strength

Equipment & Operation

Charging slot ovens

Equipment & Operation

Charging heat-recovery oven

Equipment & Operation

Wall pressure issues

Equipment & Operation

Wall pressure issues

ZKS Didier batteries 1 & 2

started up in 1984,

6.25 m high

Battery 3 built by Paul Wurth in 2010

Battery 1 demolished and rebuilt in 2012

Battery 2 said to be shut down in 2012

So, battery live was 28 years

Equipment & Operation

Wall pressure issues

Tata Steel Jamshedpur

Oldest stamp charged battery #7, built in

1989

Failures started in 2005

After long continuous improvement work, all

ovens came back by

2010

Equipment & Operation

These examples suggests that with the technology used for 6 m high stamp charged

batteries in the mid 80s, working life should

be around 30 years

This is less than what is expected for top charged batteries (40-50 years)

But it is the same that for non-recovery/heat recovery ovens, with or without stamped

charging

Blend Design & Coke Quality

ZKS blend

Local coal Ruhr coal Imported coal Pet coke Blend Content (%) 72 5 8 12 100* Volatile matter (%) 38.6 17.3 19.1 11.8 31-32 Dilatation (%) 100 -18 34 - 10 FSI 8 3 9 - Ash (%) 6 7 10 1 6 Sulphur (%) 0.72 0.80 0.80 0.85-1.70 Mean reflectivity 0.89 - 1.4 - 1.14

Blend Design & Coke Quality

Tata Steel

Main blend component: West Bokaro

Complemented with hard and semi soft Australian coals

Volatile matter (%) 26.7

Ash (%) 17.5

FSI 3

Maximum fluidity (ddpm) 3900

Vitrinite reflectance 0.97

Blend Design & Coke Quality

Tata Steel

Blend cost comparison

Blend Design & Coke Quality

Coke Quality (JSW Steel) Coking coal (%) 100 95 90 85 80 65 65 75 70 65 Semi soft coal (%) 0 0 0 0 0 15 10 0 0 0 Non-coking coal (%) 0 5 10 15 20 20 25 25 30 35 Coking time (h) 62 60 59 61 58 61 61 56 56 62 CRI (%) 23 24 25 24 24 25 25 26 26 27 CSR (%) 67 67 66 66 65 64 64 65 63 62 MICUM 10 (%) 5.6 5.7 5.5 5.8 5.3 5.3 5.7 5.3 5.9 5.7 MICUM 40 (%) 85 86 87 85 88 89 89 87 87 89

Blend Design & Coke Quality

China Committee of Coke and

Coal Resources of the

China Coke Industry

Association: by using

stamp charge, coking coal

and fat coal can be

decreased by 14%

So, there is emphasis on full utilization of stamp

charging installed

capacity

Blend Design & Coke Quality

China

CRI and CSR comparison (three blends)

Blend Design & Coke Quality

China

Blends with anthracite

Coal Ash (%) Volatile Matter (%) Sulphur (%) 45% anthracite 10.2 9.3 0.41 20% coking coal 7.7 18.5 0.44 35% 1/3 fat coal 8.8 33.2 0.45 Blend 9.0 21.6 0.42

Coke M40 (%) M10 (%) CSR (%) Ash (%) Sulphur (%) 85.6 6.6 62.1 11.3 0.34

Blend Design & Coke Quality

Summary

Main blend component: high volatile local coal

Use of soft/semisoft coals

Use of low volatile inerts like anthracite and petroleum coke, in some plants

For such blends, MICUM 10 and CSR improve in comparison with top charging (less porosity)

Recent Research

Technical University of Berlin, Germany

Stampability, modeling of stamping operation

Tata Steel R&D, India

Tar pitch/molasses to improve cake strength

Fluid pet coke/anthracite to decrease cost

RDTE, China

Influence of coke structure on high temperature behavior

Conclusions

With more than 100 Mtpa capacity installed, stamped charging became one of the most

applied technologies to decrease blend cost

and/or to improve coke quality

Adoption by China and to a less extent by India, suggests that further increase in

capacity may take place in the future

Some Universities, Institutes and Steel Companies are supporting this technology

with R&D efforts

Jorge Madias

Mariano de Cordova

metallon

Thank You