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Abstract

Contents

Introduction

Liquid iron and remains the main component in the metal stock   steelmaking. Factors that determine the economic advantages of the blast furnace process   to others, are: the duration of the campaign of blast furnaces, their performance, the unit cost of coke and the injected fuel.

pulverized coal injection into the blast furnace is an effective technology for reducing the cost of cast iron, increasing the furnace productivity and protect the environment. This idea patented as early as 1831 but its mass industrial implementation started in 80-90. XX century, after the theoretical research and development of specialized equipment,   providing efficient injection of pulverized coal in blast furnaces, explosion and fire, etc. The result was the introduction of the 80-ies. the last century in the first operation of industrial plants   Company «Armco Steel» (Ashland, USA) and ПАО «Донецксталь»-МЗ» (Ukraine). On the basis of years of experience have been formulated scientific principles of technologies that allowed strictly calculate the optimal cost of pulverized coal.

1. Relevance of the topic

In the past 30 years, the world is continuously expanding implementation of the technology with the replacement of blast furnace coke of coal injection.

Domestic and foreign practice confirms the well-known theoretical assumptions about the effectiveness of the coal injection. The advantages of using pulverized coal are also supported by the following factors:

- virtually all new or reconstructed blast furnaces were built abroad in combination with modern pulverized coal-fired plants: Spain, Brazil, South Korea, Turkey, etc.;

- in today's world with the use of pulverized coal 600 million tons of smelted iron / year, the percentage change them skip coke increased to 45-50%, and the rate of the last virtually reduced to 240 kg / t of pig iron [ 1 ];

- the mass commercialization of coal-dust technology and a corresponding reduction in coke production was determined for koksodomennogo complex reduction  capital expenditures and the areas occupied by equipment, operating costs, increase productivity, the conditions for increasing the share of coking coal in koksoshihte and improve the quality of the produced coke  reduce pollution water and air polluting emissions.

massive industrial experience, the latest theoretical developments confirm the fundamental possibility of reducing the consumption of skip coke per 1 ton of pig iron to 100-200 kg due to the introduction of technology to the blast furnace injection of 200-260 kg / iron and full implementation of the technology and comprehensive compensation [ 2 ].

Despite the undeniable successes of Ukraine in 70-90 years. the last century in the development of industrial technology with the use of pulverized coal, to date, in the use and implementation of this technology, it lags behind most capitalist countries for 20-25 years. Obviously, the question of the mass commercialization of PCI technology in blast furnaces of Ukraine with the aim of replacing part or all of their GHG and visible reduction of the skip Coke does not tolerate delay.

2. Purpose and objectives of the study

Purpose - to develop and evaluate the effectiveness of the conditions for the blast furnace number 3 PJSC "EMZ" blast furnace pulverized coal technology with the replacement of up to 60% of the coke. At the blast furnace number 3 m3 useful volume of 1719 started the construction of coal complex under the contract with Kuttner.

To evaluate the effectiveness of the proposed measures have been adopted baseline estimates of the melting furnace number 3 with a high flow of pulverized coal, pulverized coal used by the laboratory Donetsk National Technical University. The accepted method of calculation set based on the work of Professor A. Ramm [ 3 ].

as the base period of performance of the furnace was in May 2012: the performance of 2,860 tons / day; Qk skip = 464.3 kg / t; yelling Qc = 41.7 kg / t, the consumption of natural gas: 43.0 m3/t of pig iron. Blast furnace smelts pig iron using coke improved quality «Премиум», a local sinter basicity (CaO/SiO2) = 1,3, pellets SevGOK, magnesium slag basicity (CaO/SiO2) = 1,15. On the basis of the principle of full and comprehensive compensation (output from the blast of natural gas, oxygen enrichment of blast and use highly basic sinter, coke quality) have been calculated with the use of technological modes of pulverized coal, which showed that the use of the available ПАО «ЕМЗ» iron burden optimum flow of pulverized coal is 160 kg / t of pig iron. This reduces coke consumption by 170.3 kg / m (33.5%), withdrawal from the blast PG (43.0 m3/t) reduction of fuel consumption of 59.5 kg / t (10.56%), the increase in production rate of 14.5%, the cost of iron drops to 219 UAH. / ton of pig iron.



Table - Level of compensatory measures in the technological modes of pulverized coal injection

Indicators base 1 2 3 4 5 6 7
  Material consumption, kg / t of pig iron
    pulverized coal, kg / t of pig iron045135160185210220230
    natural gas, m3/t of pig iron4326000000
    agglomerate(В=1,3)498498000000
    agglomerate highly basic00715715715580490400
    agglomerate of ММК Ильича598598000000
    agglomerate of ЮГОК153153000000
    pellets of СевГОК4454459534690000
    pellets of ЦГОК 00004701039948858
    converter slag 7474000000
    briquettes from dropping out00232323232323
    iron ore (Ukraine)2424000000
    iron ore (imp.)000000160320
  Basic slag1,151,151,121,121,121,121,121,12
  О2 in the blast, %21212122,925,127,528,529,9
  Temperature blast, оС11361136120012001200120012001200



Table - Techno-economic indicators in the blast furnace process modes with injection of coal

Indicators base 1 2 3 4 5 6 7
 Productivity,
  tons / day		28292820311232393463368537613857
 Consumption of coke and coke nut,
  kg / t of pig iron		506,0475,3359,8335,7302,8271,2259,2247,9
 Consumption of fuel,
  kg / t of pig iron		564,!558,9503,6504,5496,5489,8487,8486,5
 Change in the cost of cast iron,
  UAH / t of pig iron		0,0-79,9-197,8-219,8-251,0-253,3-216,2-174,9



Increase of expense of coal to 230 kg are possible at enriching of blowing oxygen to 29,9 % and to replacement of part of agglomerate and pellets of СевГОК by the imported iron-stone.

Conclusions

The implementation of these complex measures will reduce the output of slag from 475 to 212 kg / t of pig iron (51.5%), with the charge of sulfur coming from 6.6 to 4.4 kg / t of pig iron (33%) and yield furnaceman gases at 645 m3/t of pig iron (35%). With appropriate compensatory measures real becomes possible to replace up to 60% coke skip additional fuel. Thus, we can conclude that the construction of the installation of pulverized coal by ПАО «ЕМЗ» is a necessity in becoming economically stable company.

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