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Abstract

Steel and cast-iron products, due to their low price and beneficial properties, are the most widely used among metals; their consumption has become an indicator of the economic development of countries. The characteristics of iron raw materials, in relation to current metallurgical requirements, are presented in the present this article. The globalization of the trade and development of steelmaking technologies have caused significant changes in the quality of raw materials in the last half-century forcing improvements in processing technologies. In many countries, standard concentrates (at least 60% Fe) are almost twice as rich as those processed in the mid-20th century. Methods of quality assessment have been improved and quality standards tightened. The quality requirements for the most important raw materials ‒ iron ores and concentrates, steel scrap, major alloy metals, coking coal, and coke, as well as gas and other energy media ‒ are reviewed in the present paper. Particular attention is paid to the quality testing methodology. The quality of many raw materials is evaluated multi-parametrically: both chemical and physical characteristics are important. Lower-quality parameters in raw materials equate to significantly lower prices obtained by suppliers in the market. The markets for these raw materials are diversified and governed by separate sets of newly introduced rules. Price benchmarks (e.g. for standard Australian metallurgical coal) or indices (for iron concentrates) apply. Some raw materials are quoted within the framework of the commodity market system (certain alloying components and steel scrap). The abandonment of the long-established system of multi-annual contracts has led to wide fluctuations in prices, which have reached a scale similar to that of other metals.
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Abstract

An attempt to summarize the primary iron raw materials and steel market’s hundred years history as well as influence of economic indicators on the iron ore deposit qualification for extraction has been undertaken in the paper. Steel products are crucial to the world economy, and their production has a major impact on the environment. The main factor is the huge scale of the production and growth rate, unprecedented among minerals. Iron ore and concentrates production has increased more than thirty times over the past century, and the geological resource base at the current level of consumption has provided almost 250 years of sufficiency. There have been tremendous changes in the world geography of the ore and steel industry. The iron ore mining industry is the driver of other economic activities (land transport, freight, metallurgy) and involves huge capital and human resources. The consumption of iron raw materials is also considered as an important indicator of the countries development and current or even future economic situation. Population growth remains one of the key stimulating factors. The prices of ore and iron concentrates depend on the quality of the raw material, delivery conditions, market balance and the weight of the ordered cargo. They are usually the subject of negotiations. In the past, they were long-term contracts, while short-term (yearly, quarterly) and current spot transactions are now significant. The prices of ores and concentrates in relation to steel prices are showing a strong correlation. The average iron content of the reserves has been reduced in the largest producers in the 21st century, however it does not translate into the quality of mining output. Exploitation of the richer parts of the mineral deposit is usually carried out. The high content of iron in the output is a response to the technological requirements of the metallurgy where the blast furnace charge should contain at least 56% Fe and 5–8% FeO. The current surplus of geological-mining supply (large resource base) justifies that a mineral deposit choice, destined for excavation, is economic profit maximization as well as social and environmental considerations.
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Abstract

The operational mineral deposit reconnaissance tends to evaluate its parameters to conduct safe and profitable production. Particular deposit parameters, important from the point of mineral deposit management, are estimated on the basis of observations carried out by mining geological surveys. These observations usually involve sampling, drilling, laboratory analyses and others. The use of fuzzy description to assess the parameters of the mineral deposit was proposed in the paper. In the fuzzy characteristics, an imprecise descriptive description appeared in place of a particular numerical quantity. This approach was used to description of the ore deposit features (metal content, volume, and metal yield) by assigning them specific characteristic functions, whose distributions were based on basic statistical quantities. Characteristic functions can be used to prepare operational strategies for any configuration of required deposit parameters resulting from the production management needs. For this purpose, selected logical operators of fuzzy sets were used. In the next approach to fuzzy modeling, an opportunity to characterize the deposit in a subjective approach was indicated, where the assessment of the deposit parameters is based on rough, in some way, discretionary observation and evaluation. Such model construction enabled the overall assessment of the deposit from the point of view of any parameters. Through the implementation of appropriate inference rules, adequate fuzzy control planes were obtained, which may also be useful in the context of operational mine strategy planning.
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