Theme of abstract:

"Ecological and economic estimation of use pulverised coal fuel in the manufacture of pig iron"

Performed: Butenko Natal'ya

Leader of work: Associate Professor, PH.d. Kochura V.V.

1. Actuality of a theme.
2. Purpose and problems of a theme.
3. Scientific novelties and practical value.

1. Ecological efficiency of pulverized coal injection in the blast furnace.
2. Economic efficiency of pulverized coal injection in the blast furnace.

1.Actuality of a theme.

The theme of master’s work is actual in modern economic and ecological conditions. Because the theme considers ecological and the economic benefit replacement of metallurgical coke by pulverized coal. Also natural gas becomes unprofitable kind of fuel for metallurgy as a whole, and for manufacture of pig iron in particular. Natural gas has high price and injection of pulverized coal in the blast furnace will allow to lower consumption of natural gas or to refuse it. Pulverized coal injection in the blast furnace will allow reducing power-capacity of the metal product. Coked coals are the most high cost and remote and coked coals are necessary for manufacture of coke. But gas and power coals are appropriate for preparing pulverized coal. Therefore development of technology of pulverised coal injection in the blast furnace will define reduction in the charge of coke to 40 % and will allow to extract coked coals according to geological resources, to expand extraction of the cheapest coals.

2.Purpose and problems of a theme.

The purpose and problems of the theme is to study and make a complex estimation of technology of pulverised coal in manufacture of pig iron; to consider advantage and disadvantage of replacement of metallurgical coke by pulverized coal; to result the economic calculation; to make the analys of influence this technology on environment, to provide its ecological safety. The economic calculation have to confirm efficiency of introduction pulverized coal injection at the metallurgical enterprises of Ukraine.

3.Scientific novelties and practical value

Scientific novelty of master’s work consists in studying influence of technology of pulverized coal injection in a forge of blast furnaces on an environment. Practical value of master’s work is consisted in achievement maximal coke and power economy in conditions of increasing requirements on ecology, power consumption decreases of metal products.

1.Ecological efficiency of pulverized coal injection in the blast furnace.

Problems of ecology have got an exclusive urgency for last years. Preparation of pulverized coal is accompanied by smaller pollution of an atmosphere and water pool, than manufacture of coke. Manufacture of coke is the largest source of environmental contamination by a lot of chemical compounds. Manufacture of coke is picked out the huge quantity of harmful substances: hydrogen sulphide, sulphurous anhydride, carbon oxidize, phenols, ammonia, naphthalene, a hydrocianic acid. The specific size emissions coke makes on 1 t coke: a dust - 2,66 kg; gas – 7600 m3, harmful substances – 4,07 kg. The quantity of emissions in an atmosphere by manufacture of coke and manufacture of pulverized coal is resulted in table 2.1.

 
Table 2.1 shows that manufacture of pulverized coal is cleaner than manufacture of coke.

2. Economic efficiency of pulverized coal injection in the blast furnace.

It is spent up to 2/3 from the general charge of the power resources for manufacture of pig-iron. Cost of fuel makes 30 - 40 % from the general cost of pig-iron. Ukraine has a great stocks of coal. Significant part of coals is made up power coals. The technology of pulverized coal injection is the most perspective. It will allow to raise competitiveness of the Ukrainian pig-iron. Application of pulverized coal will allow to improve ecological parameters of the ferrous metallurgy enterprises.
Different kinds of coal are used on plants. There are gas coal, lean coal, coke coal and so it. Resources for preparing of pulverized coal are provided with stocks of coals and existing capacities for their extraction. The need in raw materials for preparation of pulverized fuel can be satisfied due to gas coals.
A concentrate of lean coals injection in blast furnace will allow to decrease production of metallurgic coke on 4,5 million t. The structure of charge, which used for preparing of coke, will improve in this case. So, the maintenance of gas coals will decrease for 4,7 million t, and lean coals will be completely deduced from a raw-material base of coking.
A gas coals injection in blast furnace will allow to decrease production of metallurgic coke on 3,6 million t. At inflation in blast furnaces of gas coals the need for domain coke decreases on 3,6 million т, and the need in шихте decreases accordingly for 5,0 million t. It will allow to refuse completely use of lean coals and to reduce individual share of gas coals by 3,7 million t.
Improvement of coke quality, as a result of a exclusion from batch for coking gas and lean coals, will lower the charge of coke accordingly on 3,25 % and 3,85 % and will raise productivity of blast furnaces on 4,03 and 4,84 %. Analytical calculation and the analys of experience of applications pulverized coal from different marks of coal have accepted following parameters of work of blast furnaces(Table 2.2). Table shows that the maximal decrease in the charge of coke and increase in productivity of the blast furnace can be reached of anthracites injection with ashes fuel of 4,5 and 7,5 %.

 Table 2.3 shows the economy effect of pulverized coal injection in manufacture of pig iron

The maximal decrease in the charge of coke and increase of productivity can be reached by anthracites injection in a forge of blast furnaces. But application of anthracites is less effectively, than lean coals, because fuel has high fixed price.
Gas and lean coals have identical quality. Lean coals provide greater on 22 % economy of coke, then gas coals. Annul economic benefit increases in 1,8 times. Smaller efficiency of application pulverized coal from gas coals is defined by the smaller maintenance of carbon in fuel and according to smaller factor of replacement of coke by pulverized coal. Application of less cindery concentrates provide additional economy in manufacture of pig iron, but as a result concentrates appear less effective because have the high procuring price of fuel.
Thus, pulverized coal injection in a forge of a blast furnace allows considerably to reduce the charge of coke (up to 40 %), consumption of natural gas without change of productivity of a blast furnace. It provides recept of economic benefit. Pulverized coal injection is one of the most effective actions developed and prepared for wide introduction.

The technology of injection coal allows to reduce the charge of coke and natural gas and to receive significant economic benefit. Also it is favorable from the point of view of ecology. Complex efficiency of application pulverized coal in manufacture of pig iron is accompanied by improvement of parameters of work of blast furnaces, reduction of emissions in an atmosphere of harmful substances and pollution of water pool, reduction of a capital intensity, the areas borrowed by the equipment and increase of labour productivity in coke and and metallurgical industry.
This master's work will be finish in December 2007.

Literature

1. Гольдерман Г.Д. Вдувание угольной мелочи в горн доменной печи за рубежом. – «Бюллетень ЦНИИИ ЧМ», 1964, №10.
   
2. Леонидов Н.К. Применение кислорода, вдувание углеводородов и других материалов. – М.:ВИНИТИ, 1972, (Итоги науки и техники, т.5).
   
3. Применение пылеугольного топлива для выплавки чугуна. /Под ред. Ярошевского С.Л. М.:Металлургия, 1974. – 184 с.
   
4. Старк С.Б. Газоочистные аппараты и установки в металлургическом производстве. – М.:Металлургия, 1990. – 399 с.      
   
5. Юдашкин М.Я. Очистка газов в металлургии. – М.:Металлургия, 1976. – 376 с.
   
6. Ярошевский С.Л. Выплавка чугуна с применением пылеугольного топлива.- М.:Металлургия, 1988. – 174 с.