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MANAGEMENT OF COKING COAL RESOURCES

By: , Posted on: November 7, 2018

The ‘coking coal chain’ primarily consists of exploration, extraction, processing, carbonisation, and steel making – while storage and transportation form the connecting link. In recent years, supply chain management has grown in popularity and usage. The Internet forms tighter links in integration of key business processes from initial extraction of raw coal to end customers through different stages of process techniques.

2.0 Supply Chain Management

The important technical parameters in the business of coking coal are presented in Figure 1. Each process identified should be able to work under optimum conditions, commonly by vertically    integrating processing with mining – something called “forward integration.” In contrast to vertical integration, outsourcing may provide many advantages for mining enterprises. Outsourcing of coal preparation plants can provide better quality and cost savings. Acquiring a mining lease outside the country is called offshoring, and this adds a new dimension to the supply chain strategy of globalization. Offshoring is the practice of locating mining interests in other countries; a practice that is closer to vertical integration than outsourcing. Offshoring firms are motivated to secure the supply of coal; however, this carries opportunities, challenges, and threats (Ritzman et al., 2007). There is a new focus on global mining management. In some cases, steel makers own all the units of the coking coal chain. 

FIGURE 1 Supply chain management of coking coal.

3.0 Geological Exploration

Figure 2 elaborates on the collection of different data and how best to use them regarding excavations, choice of mining machinery, safety of the mine environment, and subsurface water.

 

 

 

 

 

 

 

 

FIGURE 2 Collection of data during exploration.

3.1 Assessing the Grade of an Exploration Block

Exploration supplies not only coal quality data from the seams but also much of the additional information required for successful mining activity. These data are essential for assessing the deposit and for undertaking subsequent planning. Thus, exploration needs to be carried out within as short a period of time as possible and at a minimum cost. Moreover, exploration needs to make

essential data available as quickly as possible. Although this is not the topic under discussion here, samples from and data on coal quality in the exploration stage are very important. During exploration, samples are taken from drilling cores that are obtained either from conventional coring processes or via a wireline coring technique. The latter method involves core recovery being greater than 99% and the whole operation being very rapid. Geophysical borehole surveys also play an important role in exploration. Geophysical surveys can be executed both in an open borehole and in a wireline core rod. Comprehensive computer-aided programs are available to interpret the data from geophysical logging. In the event of core loss, geophysical logging ensures the delimitation of seams. Core logging in conjunction with geophysical surveys provide the most accurate and reliable data. It is here that the computer-aided Kriging method, which is based on a geostatistical technique, is finding wider application. Reserves of coking coal are severely limited. These reserves require careful exploitation for the long-term health of the steel industry. The whole coalfield can be divided into different blocks, each requiring detailed planning based on data from geological exploration and current mine workings. Similarly, the grade of each block needs to be determined so as to make an integrated plan regarding long-term quality control. This can be achieved by following the sequence of activities shown in Figure 3. Operational planning is a very important aspect since coal quality has to be maintained within regions of unknown local geology.

 

 

 

 

 

 

 

 

FIGURE 3 Estimating grade of a block.

4.0 Steel Industry

Steel is ubiquitous in the everyday objects used by humanity. The steel industry has become the backbone of the economic development and industrial growth of a country. There is need for additional steel capacity, goes without saying. Growth in the steel industry stimulates the entire economy by conservative use of natural resources, development of engineering industries, employment opportunities, research and development, and the building of infrastructure. In short, the industrial development of a country hinges on steel consumption, which has to be enhanced.

4.1 Technological Innovations

Indian steel plants have not been able to keep pace with advances made by plants in developed countries. India’s blast furnaces are operating under peculiar and unique conditions: high ash content of cokes, high alumina/silica ratio in iron ores, and high gangue content in flux. This has affected productivity, coke rate, and the quality of hot metal. These indices are used to judge the performance of blast furnaces. Areas in need of improvement in productivity include burden preparation and distribution, level of injections, high top pressure, blast modification, oxygen enrichment of blast, instrumentation, automation, and control. Measures that can be used to improve blast furnace productivity are presented schematically in Figure 4 and described briefly:

■ Beneficiation of coking coal, iron ores, and flux.

■ Blending of raw materials fed to coke ovens, sintering plants, and blast furnaces.

■ Improvement in coke making such as preheating the coal charge, selective crushing of coal,

stamp charging, dry quenching, and partial briquetting of the coal charge.

■ Conversion of blast top pressure to above 3 bar.

■ Use of formed coke made from noncoking coal, which can replace about 30% of normal coke

consumption.

■ Raising the blast temperature to about 1200 °C by humidifying the blast.

■ Pulverized coal injection (PCI) of noncoking coal into blast furnaces at the rate of 250 kg per

tonne of hot metal and enriching the blast with 2–3% oxygen.

■ Careful sizing of raw materials fed to blast furnaces in the context of permeability and

reducibility of burden.

■ Insuring fines below 0.5 mm do not exceed 5%.

■ Insuring agglomerates in the form of pellets and sinters are used because of their specific

advantages.

■ Implementation of high basic sinter, optimum slag regime, lime dust injection, external

desiliconization, and desulfurization of hot metal.

■ Recovery and utilization of waste heat in steel plants.

■ Instrumentation, automation, and computer control in all areas of integrated steel plants.

In addition to efforts made to improve the performance of blast furnaces, directly reduced iron – produced by noncoking coal – is going to play an important role in conserving India’s reserves of coking coal. It is important to keep up with technological developments taking place in the steel industry across the world. The economic survival of the steel industry depends upon the effective planning and implementation of technology.

FIGURE 4 Technology developments for improvement in iron making.

5.0 Framework

A panoply of tools (Kumar, 1995) from operations research, management sciences, statistics, systems analyses, productivity management, as well as detailed economic and econometric study have been appropriately used to probe the multidimensional problems of the coal industry to formulate feasible solutions. To support the envisaged growth of steel industry (i.e., to meet the increasing demand for coking coal), key areas having potential for further improvement have been identified (see the framework provided in Figure 5). Such a framework may lead to establishing a constructive dialog, help explore issues of concern, sort fact from fiction, and identify a concrete and coordinated way forward.

 

 

 

 

 

 

 

 

 

FIGURE 5 Framework for future development.

About the book

Management of Coking Coal Resources provides a one-stop reference that focuses on sustainable mining practices using a four-point approach that includes the economical, governmental, societal, and environmental aspects of coal exploration, coking coal mining, and steelmaking applications.

Readers will find a multidisciplinary reference that presents the broad range of applications, techniques, and methodologies used in maintaining coking coal quality from exploration through extraction.

The book is available now on the Elsevier store. Enter STC317 at the checkout for up to 30% discount.

 

References

Kumar, D., 1995. Optimum Exploitation of Coking Coal Resources for the Growth of Indian Steel Industry. Glückauf Forschungs-Hefte 56 (6), 185–188.

Kumar, D., Kumar, D., 2016, Management of Coking Coal Resources, Elsevier, Waltham, MA, USA.

Ritzman, L.P., Krajewski, L.J., Malhotra, M.K., Klassen, R.D., 2007. Foundations of Operations

Management. Pearson, Prentice Hall, Toronto.

 

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