P. I. Chernousov

The role of alkalis and conserving resources in blast-furnace smelting

In ferrous metallurgy, the potential for conserving resources is often determined by the behavior of the impurity elements in metals production. This behavior may be highly complex, and its features may be interpreted differently by different experts. For example, the presence of zinc and alkali metals in the blast-furnace charge is known to result in excessive coke consumption, a reduction in the productivity of the furnace, an increase in the yield of top dust, shortening of the campaign, and in some cases to complete destabilization of the smelting operation. In choosing a technology for blast-furnace smelting, accounting for the entry of alkali metals and zinc into the furnace is one of the most important factors that determines the expediency of controlling the heat “from the top” or “from the bottom” features of the slag formation process, the gasdynamics of the smelting operation, and other characteristics.

Effect of the Removal of Arsenic from Metal on the Environment

demand for ultrapure metals and alloys has increased in recent years, which is making it necessary to elevate product quality in order to reliably maintain market share. On the other hand, requirements are also being tightened in regard to toxic emissions. This trend is embodied in the promulgation of the new standards ISO-14000. Together, these two factors , along with the increasing use of new sources of raw materials – new deposits, industrial by-products, and household wastes – are making it necessary to carefully analyze the distribution of impurity elements between the main products and by-products of metallurgical processes. Special attention should be given to the elements that are harmful both to metallur-gical products and to the environment. One of the elements most deserving of such attention is arsenic, since it is fairly widespread in the traditional raw materials – ores, coal, and secondary resources. This situation presents additional problems related to the need to remove arsenic from raw materials during the preparatory stages and in metal production processes. Arsenic is an impurity which adversely affects the quality of the products of ferrous metallurgical plants. Arsenic tends to undergo dendritic segregation during the crystallization of steel ingots, which then leads to the formation of striated structures and makes the mechanical properties of the rolled product more anisotropic. A high arsenic concentration in steel lowers its ductility properties, reduces its strength characteristics, adversely affects weldability, and somewhat increases its tendency to undergo strain-hardening. The presence of arsenic in structural carbon and alloy steels reduces their hardenabil-ity and makes them more susceptible to reversible and irreversible temper brittleness. In the course of its removal from raw materials and metals, arsenic enters slag (in blast-furnace smelting) or changes to the gaseous state (mainly in pellet and sinter production and the blast-furnace process). Thus, arsenic enters the hydro-sphere and atmosphere of industrial regions through metallurgical waste products (solid slag, sludge, gaseous emissions, etc.). As a result, one important problem which arises in the production of metal from arsenic-bearing raw materials is study of the consequences of the removal of arsenic from those materials and the behavior of arsenic in the environment. Unfortunately, these matters have thus far received little attention. We will examine the environmental aspects of metallurgical production involving arsenic – one of the elements that poses a significant danger to the environment. It has a toxic effect not only on individual organisms …

METHODOLOGY FOR ANALYZING MICROELEMENT BEHAVIOR IN BLAST FURNACE SMELTING

Methodology for analyzing and predicting the behavior of microelements in blast furnace smelting is developed, taking account of process features, the form of microelements present in metallurgical materials, and the method of their introduction into a blast furnace. The procedure includes experimental, research, and calculation sections. As a result of comparing experimental data and the results of modelling, element distribution between pig iron, slag, and the gas phase of the blast furnace process is determined. It is established that the increase observed recently in the microelement content in blast furnace sludge is mainly connected with features of the behavior of the proportion of these microelements within the composition of the organic part of coke and coal dust fuel.

Improving methodological approaches to the systematic evaluation of greenhouse-gas emissions in ferrous metallurgy

A survey is made of the main methodological approaches used to evaluate greenhouse-gas emissions in ferrous metallurgy. The concept of the carbon content of products is formulated as a comprehensive index of the aggregate greenhouse-gas emissions associated with each conversion in the manufacture of a given type of product and its processing and use beyond the metallurgical plant. A method is proposed for calculating the carbon content of products. Use of the proposed approach makes it possible to solve a range of problems encountered in monitoring and predicting emissions and performing environmental-economic analyses of the efficiency of metallurgical plants and the industry as a whole.

Feasibility of Improving Energy Efficiency When Using Technologies That Produce Iron Outside the Blast Furnace

Calculations and a comparative analysis which were performed show that compared to blast-furnace smelting and converter steelmaking, the expediency (based on indices for greenhouse-gas emissions and the energy content of the product) of non-blast-furnace-based technologies for iron and steel production depends on the extent to which secondary energy resources (SERs) are used: the efficiency of SER use and the use of steel scrap in steelmaking.

AUTOMATED SYSTEM FOR MONITORING SUPPLIES OF FERROUS-METAL SCRAP

A noncontact method is developed for monitoring reserve stores of ferrous-metal scrap.

The blast furnace as a multifunctional device

Conclusion1.In the twenty-first century, metallurgy will remain the basic branch of the world economy, but the conditions of its functioning will change substantially. On one hand, the exhaustion of resources of iron ores will lead to the predominant processing of compound polymetallic ores. On the other hand, the need for conserving resources will make the extraction of one basic metal with all others going to waste impossible.2.Of all the known installations for obtaining primary metal, only the blast furnace can combine processing of compound ores with meeting stringent requirements on conserving resources and preserving the ecology. This objectively makes the blast furnace a leading metallurgical installation in the twenty-first century.3.Calculations show that 20–30% of the reserved capacity of the blast furnace production in Russia can be used for processing technogenic waste and garbage.4.In the twenty-first century, the blast furnace will become a multifunctional device, solving both metallurgical and sanitary-ecological problems. In the future, blast furnaces will be used for producing pure pig and cast irons, ferroalloys, polymetallic alloying compositions from compound ores and technogenic waste, slags of specified compositions and properties, gasification of solid fuel, and the processing of solid garbage.