SU1486523A1 - Method of producing ferronickel - Google Patents

Description

The invention relates to metallurgy and can be used in the production of ferronickel from oxidized nickel ores. The purpose of the invention to reduce the loss of iron and nickel. In the smelting of ferronickel in reductive electric smelting, the resulting metal is subjected to desiliconization in an oxygen converter with an acid fuIz. The invention relates to metallurgy and can be used in the process of refining ferronickel.

The purpose of the invention is to reduce the loss of iron and nickel.

The method is as follows.

Refining ferronickel in acidic converter to a low content, silicon is necessary due to the fact that.

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by grading to a silicon content of 0., 1—

0.3%, then the metal is poured into the ladle is treated ^- it Karbjurizator, cooled to 1250-1380 C, is introduced soda ash and then poured into an oxygen converter ferronickel with the main liner, it is poured into the previous final slag smelting and refining is completed. Such treatment reduces the temperature of ferronickel before pouring it into the main converter. The low temperature of the metal in combination with the presence of the previously prepared slag of high oxidation and basicity allows for efficient dephosphorization. Desulfurization, .® ferronickel after processing it with a car | / bureauser eliminates an additional 1 ^ supply of sulfur from metal waste and carburizer into the main converter. ₌ Yose it allows to reduce the displacement of metal in the main converter, to reduce the waste of iron and the loss of nickel with converter slags. 1 tab.

along with the high temperature of the metal, it provides a high rate of dissolution of carbon in ferronickel when it is treated with a carburizer.

The silicon content in ferronickel before it is drained into the ladle from the sour lining converter should not exceed 0.3%. Higher concentrate silicon is negatively affected

at the rate of dissolution of carbon in

1486523 A1

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ferronickel, in addition, increases the amount of silicon introduced into the main converter. At the same time, during slagging, the basicity of slag and the efficiency of metal dephosphorization decrease. When the silicon content before pouring into the ladle is less than 0.1%, the high oxidation of the metal causes an intense boiling of the melt in the ladle, accompanied by emissions of the metal being processed.

Processing the carburizer leads to a simultaneous decrease in the temperature of the metal in the ladle and a decrease in the melting temperature of ferronickel, which cools the melt before zapivka in the main converter to a low temperature, while maintaining sufficient overheating of the metal above the melting point.

After treatment of ferronickel with a carburizer, extrahepental desulfurization is carried out, which helps reduce the amount of sulfur introduced into the main converter, reduce the duration of refining and the loss of metal with slags.

After pouring the ferronickel into the main converter, slag of the final stage of the previous smelting containing 40–50% of iron oxides, 24–28% of calcium oxide at a ratio of calcium oxide to silica in the slag is more than three, and the refining is continued. The low temperature of the metal, together with the pouring of pre-’prepared slag, contribute to the effective dephosphorization of the melt, which reduces the duration of the metal blowing in the main converter, the amount of oxidized iron and the loss of nickel from the slag that is drained from the converter. The amount of slag poured into the main converter is 5-20% by weight of the metal.

Ave. The study of the possibility of reducing the loss of metals upon receipt of ferronickel in accordance with the proposed method was performed during the processing of furnace-type ferronickel composition,%: 4.2-4.4; 0.20.25 Co; 2.1-2., 3 C; 3.5-4.5 8ί; 1.61.8 Cr; 0.09-0.125 P; 0,16-0,19 8, discharged from the ore-thermal furnaces with a temperature of 1220-1260 ° C. 0bearing \ ferro-nickel silicification led sour

a native sour-lined converter using metal waste and source nickel ore as coolers. By reducing the concentration of silicon to the required limits, the metal with a temperature of 1600-1650 ° C was poured into a ladle, to which anthracite shtyb was preloaded in an amount of 2.5-3.5% by weight of the metal. After the metal was drained from the acid converter for 10-15 minutes, the metal was purged with nitrogen through a lance dipped into the melt to complete the dissolution of the carburizer fed into the ladle. After that, during the overflow from the ladle to the ladle, ferronickel was desulfurized with preliminary molten soda ash in an amount of 10-12 kg / ton of ferronickel. Then, it was boiled out of the ladle, sulphurous slag, and the metal was poured into the main oxygen converter, where the slag obtained at the final stage of the previous smelting was added in an amount of 8-10% by weight of ferronickel. After this, oxygen purging was continued according to the technology adopted in the workshop using limestone as a cooler. In this case, the total duration of the metal purge in the acidic and basic converters was recorded until the desired composition of the ferronickel was obtained for the content of phosphorus and sulfur (5.0.03%; Р- ^ 0.03%). *

The results of the melts are shown in the table.

The lowest metal losses were observed during melt processing in accordance with the proposed method. !

Experience 1, due to the high oxidation of the metal being drained from the acidic converter, the carburization process was accompanied by rapid boiling of the melt in the ladle. To eliminate possible emissions, the metal was poured from the converter in separate portions, which led to a significant increase in the duration of the melting cycle. In experiments 5, 6, 7, the efficiency of desulfurization of ferronickel with soda ash and dephosphorization was low, which led to an increase in the duration of metal refining in the converter and an increase in metal losses.

Using the proposed method allows to reduce iron losses

and nickel in the refining of ferronickel in the main oxygen envelope5

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Tere, to organize the production of new grades of ferronickel of increased V purity.

Claims (1)

The method of obtaining ferronickel, including melt smelting, input of soda ash, pouring the melt into the sour-lined converter, purging with oxygen, discharging the melt into the ladle, pouring the melt into the convection with oxygen, characterized in that, in order to reduce iron loss and nickel, after you 5 start-up of the melt from the acid converter, the carburizer is additionally introduced into the ladle and the melt is cooled to 1250–1380 ° C, after which the soda ash is introduced, and the melt in the acid converter is blown to a silicon content of 0.1–0.3%, and the main converter is additionally added werther with main lining and Incomplete slag previous smelting. one Experience Indicators ------- 1 -------- g ------- ___ _ g ------- ¹ I ² 1 ³ 1 ⁴ 1 ⁵ 1 ⁶ 1 ⁷ 1 ⁸ The content of silicon in ferronickel at plum from sour Converter,% The chemical composition of ferronickel before pouring into the main converter, 0.02 0.1 0.2 oh w 0.8 0.2 0.2 1,3 Nickel 5.2 5.1 5.1 5.3 5.2 5.2 5.1 5.2 Cobalt 0.26 0.23 0.26 0.27 0.22 0.24 0.25 0.25 Chromium 0.5 0.6 0.7 0.8 1.2 0.6 0.7 1.2 Silicon 0.02 0.1 0.2 0.3 0.8 0.2 0.2 1,3 Carbon 3.6 3.5 3.6 oh oh 2.1 3.2 3.2 1.6 Sulfur 0.05 0.06 0.035 0.038 0.067 0.07 0.062 0.065 Phosphorus The temperature of ferronickel before pouring into the main 0.09 0.105 0.095 0.11 0.115 0.105 0,100 0.105 werter, C Duration 1320 1250 1320 1380 1660 1210 1620 1540 duvki min Lost with slag, 20.5 20.0 19.5 20.0 26.0 27.0 26.5 29.5 t Iron 6.0 3.8 3.9 4.0 6.8 7.1 6.9 8,8 Nickel 0,008 0,009 0,009 0,009 0.012 0.015 0.014 0.022