SU1447867A1 - Method of producing steel in converter - Google Patents

Abstract

This invention relates to ferrous metallurgy, in particular to steelmaking in oxygen converters. The purpose of the invention is to increase the yield of the molten metal, decrease the duration of smelting and increase the fair phosphate slag, achieved by neutralizing the final slag in the converter with a combined additive of 19.8-39.6 kg / ton of lime steel and (or) dolomite and 3, 3-9.9 kg / t titanium-magnesium steel waste of the following composition, wt%: magnesium 3-8, titanium 1-4, magnesium oxide 6-10, titanium dioxide 3-6, magnesium, sodium, potassium chlorides and kalyda rest. As a result of using the technology, the consumption of pig iron is reduced by 6.8 kg / t, lime by 13.3 kg / t, the content in the slag is increased. 2 tab. SS

Description

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The invention relates to the field i of ferrous metallurgy, more specifically to the production of steel in oxygen converters from phosphorous iron 4

The purpose of the invention is to increase the yield of liquid metal, reduce the duration of melting, and decrease the quality of the phosphate.

The essence of the invention is in ToMj that in swimming trunks, leaving the entire final shpak of the previous smelting to eliminate popping and emissions when casting iron into the converter and speeding up slag formation, neutralization of the final slag is carried out by joint addition of 19.4-39.6 kg / ton of lime steel and (or ) dolomite and 3.3-9.9 kg / t of titanium-magnesium steel production. Studies have shown that the goal is achieved only with the indicated costs of reagents,

The chemical composition of the sludge is determined by the characteristics of titanium-magnesium production.

The use of waste in the amount of less than 3.3 kg / t of steel does not ensure the acceleration of slag formation due to the insufficient amount of reagents, which have a strong thinning effect on the final slag. The addition of waste in the amount of more than 9.9 kg / ton of steel does not cause doubts in accelerating the process. slag formation, however, a significant dilution effect of waste components does not ensure in this case the complete neutralization of the final slag, which is accompanied, as already noted, either by an increase in the duration of smelting, i.e. production losses, or a decrease in the yield and an increase in the consumption of materials and pig iron ..

The use of lime in the amount of less than 19.4 kg / ton of steel does not ensure the achievement of this goal due to the inability to completely neutralize the final slag. The use of lime in the amount of more than 39.6 kg / ton of steel requires an increase in the consumption of mineralizer over 9.9 kg / ton of steel to accelerate slag formation. However, in this case, due to the increase in the total mass of slag in the converter, the process does not evenly proceed. Purge is followed

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intense emissions of metal and slag.

Thus, to more fully utilize the physical heat of the final slag, speed up slag formation and eliminate claps and emissions when zapivka in the converter of cast iron, neutralization of the final shpak must be carried out by joint addition of waste of lime and (or) dolomite in the amount of 3.3-9.9 and 19 , 4-39.6 kg / t of steel, respectively. The correctness of the choice of the optimal values of the parameters follows from the data given in table.

Technological and techno-economic indicators of the process with various options before phosphorus iron is given in Table 2.

Below are examples of the implementation of the method of production of steel from phosphorus iron in heavy-duty converters KMK,

Example 1, In the converter (300 tons, all the slag of the previous smelting is left, 9 tons (29.2 kg / t) of lime and 2 tons (6.5 kg / t) of waste are placed:

titanium and magnesium production. The shpak was poured, 105 tons (340.7 kg / t) of scrap were poured over and 255 tons (827.4 kg / t) of pig iron containing 0.68% manganese, OLZ% silicon, 0.980% phosphorus and sulfur were poured in. 4 Purge according to current technological design. The oxygen consumption for the first period is 13050 nm, the blowing is stopped right, the metal contains 0.73% carbon and 0.089% phosphorus. The second period ends-at 1615 ° C and a content of 0.05% carbon, 0.010% phosphorus and 0.013% sulfur "

Melting cycle 60.6 min. Oxygen consumption is 19800 nm, lime is 132 kg / t, and the yield of steel is 85.6%,

Example 2 12 tons (39.6 kg / ton) of lime and 3 tons (9.9 kg / ton) of titanium-magnesium production were set on the slag forcing the slag into the converter, the slag was completely left in the converter, 105 tons were poured (346.3 kg / t) of scrap and pour 250 t (824.5 kg / t), pig iron with a content of 0.63% manganese, 0.78% silicon, 1.050% phosphorus and 0.034% sulfur. The consumption of oxygen for the first period of melting is 133250 nm, the blowing is stopped when the nonall content is 0.68% carbon and 0.102% phosphorus. Metal temperature 1565 s. The second period ends at 1615 ° С with a content of 0.06% carbon, 0.012% phosphorus and 0.012% sulfur,

Tdikl smelting 61.0 min, carbon consumption - 19870 nm3, lime 134 kg / t, and the yield of steel 85.4%,

Example 3. In the converter 6 t (19.8 kg / t) of lime 1 t (3.3 kg / t) of titanium-magnesium production waste are placed on the slag of the previous melting, then part of the slag is poured into the bowl, 100 t (329.5 kg / t) of scrap and pour 255 t (840.2 kg / t) of pig iron containing 0.70% manganese, 0.74% silicon, 0.927% phosphorus and 0.038% sulfur. Melting blow in

The type consists in more complete use of the physical heat of the final slag and improvement of the slag regime of converter smelting and, as a consequence, a reduction in the consumption of pig iron by 6.8 kg / t, lime by 13.3 kg / t, a reduction in the duration of smelting, an increase in the yield of suitable steel and 10 improvements quality phosphate spack.

Claims (1)

Invention Formula The method of steel production in the converter is 15, which includes leaving co-eternal slag, neutralizing it, adding scrap, pouring iron, entering slag-forming materials and two-stage blowing with intermediate two periods and finish at 1605 C 20 slag downloading, differing in the content of 0.06% carbon, 0.008% phosphorus and 0.020% sulfur,, Oxygen consumption for smelting 19650 them, incl. for the first period 13,100 nm, lime consumption 124 kg / t, yield of 85.5%. Melting cycle 59.3 min, Doduvka on these heats did not hold, blowing took place without emissions, t, e, blowing due to emissions did not stop, which ultimately led to a reduction in the duration of allowances and was one of the reasons for increasing the yield of the metal compared to the known method. The technical advantages of the proposed method are compared with the flow and with the fact that, in order to increase the yield of liquid metal, reduce the duration of smelting and improve the quality of the phosphate slag, 25 neutralizing the final slag is carried out by joint addition of 19.8 39.6 kg / ton of lime steel and or dolomite and 3.3–9.9 kg / t of steel of titanium-magnesium production waste of the following composition,%: Magnesium 3-8 Titan1-4 Magnesium oxide 6-10 Dioxide titanium3-6 Magnesium chlorides, rub, potassium and Calcium Else. . 35 The type consists in a more complete use of the physical heat of the final slag and the improvement of the slag regime of converter smelting and, as a consequence, a reduction in the consumption of pig iron by 6.8 kg / t, lime by 13.3 kg / t, a reduction in the duration of smelting, an increase in the yield of suitable steel and an improvement in quality phosphate spack. Invention Formula The method of steel production in the converter, which includes leaving co-eternal slag, neutralizing it, adding scrap, casting iron, introducing slag-forming materials and two-stage blowing with intermediate 5 and in order to increase the yield of the liquid metal, decrease the duration of smelting and improve the quality of the phosphate slag, 5 neutralizing the final slag is carried out by a joint additive of 19.8–39.6 kg / ton of lime steel and or dolomite and 3.3 -9.9 kg / t titanium-magnesium wastes steel production of the following composition,%: Magnesium 3-8 Titan1-4 Magnesium oxide 6-10 Dioxide titanium3-6 Magnesium chlorides, rub, potassium and Calcium Else. . Table 1 five 19.6-39.3 More than 39.3 Less than 19.6 19.6-39.3 19.6-39.3 Number of heats (08 kn) Material consumption for slag thickening, kg / t: lime waste titanium production The chemical composition of cast iron,%: Table 2 15 20 ten 29.4 13.1 28.3 6,6 The yield of liquid metal,% 87.2 The yield of steel,% 85,5 Duration of melting, mnn 60,3 1A478678 Continued tabl, 2 86.2 84.8 64.0