SU832282A1

SU832282A1 - Method of producing cast iron in cupola

Info

Publication number: SU832282A1
Application number: SU792796894A
Authority: SU
Inventors: Феликс Стафанович Раковский; Евгений Романович Беляев; Юрий Степанович Щекалев; Михаил Леонидович Великанов; Владлен Иванович Шулаев; Владимир Сергеевич Радя; Анатолий Анатольевич Филиппенков
Original assignee: Уральский Научно-Исследовательскийинститут Черных Металлов
Priority date: 1979-07-13
Filing date: 1979-07-13
Publication date: 1981-05-23

Description

(54) СПОСОБ ПОЛУЧЕНИЯ ЧУГУНА В ВАГРАНКЕ(54) METHOD OF OBTAINING IRON IN WAGRAN

II

Изобретение относитс к черной металлургии и может быть использовано при получении чугунов дл отливок в ваграночных печах.The invention relates to ferrous metallurgy and can be used in the production of cast iron for castings in cupola furnaces.

Известен способ получени чугуна дл отливок с использованием известн ка в качестве ваграночного флюса 1.A known method for producing cast iron for castings using limestone as a cupola flux 1.

Недостатком такого способа вл етс расход тепла .на разложение известн ка, позднее шлакообразование и повышенный угар (10 - 20%) кремни и марганца, снижающий литейные и механические свойства чугуна и вызывающий необходимость его дополнительного легировани кремнистыми и марганецсодержащими ферросплавами. Кроме того, применение известн ка снижает температуру чугуна вследствие расхода тепла на его разложение и повышает требование к его качеству по содержанию вредных примесей, увеличивающих брак отливок. Последнее требование усиливаетс при работе вагранки на коксе или термоантраците с повышенным содержанием серы.The disadvantage of this method is the consumption of heat for the decomposition of limestone, late slag formation and increased waste (10-20%) of silicon and manganese, which reduces the casting and mechanical properties of cast iron and necessitates its additional doping with silicon and manganese-containing ferroalloys. In addition, the use of limestone reduces the temperature of the iron due to the consumption of heat for its decomposition and increases the quality requirement for the content of harmful impurities, castings that increase the waste. The latter requirement is enhanced when the cupola operates on coke or thermoanthracite with a high sulfur content.

Цель изобретени - повышение температуры чугуна и качества отливок.The purpose of the invention is to increase the temperature of the iron and the quality of the castings.

Поставленна цель достигаетс тем, что вместе с флюсом, содержащим известн к.The goal is achieved by combining with a flux containing limestone.

ввод т марганцовистый шлак, вз тый в соотношении с известн ком, равным 1 : (0,25 - 2,5), а их суммарное количество составл ет 3 - 6% от веса металлошихты.Manganese slag is introduced, taken in proportion to limestone, equal to 1: (0.25 - 2.5), and their total amount is 3-6% by weight of the charge.

Шлаки от производства марганцевых ферросплавов содержат 30 - 50% SiOj, 15 - 45% СаО, 10.-20% МпО, 3 - 8% AlaO 1-5% MgO, а также до 10% Мп в виде включений ферросплавов и незначительное количество фосфора (0,005 - 0,025%.Slag from the production of manganese ferroalloys contain 30 - 50% SiOj, 15 - 45% CaO, 10.-20% MpO, 3 - 8% AlaO 1-5% MgO, as well as up to 10% Mn in the form of inclusions of ferroalloys and a small amount of phosphorus (0.005 - 0.025%.

В процессе расплавлени такой смеси на основе марганцовистого шлака быстро образуютс легкоплавкие жидкоподвижные ваграночные шлаки, хорошо смачивающие чугун и предохран ющие его поверхность от окислени . При этом распределенный в жидкой основе ваграночного шлака известн к в зоне высоких температур разлагаетс с выделением СОд, интенсифицирующего растекание жидкой основы ваграночного шлака на открытых поверхност х незащищенного металла и снижающего тем самым угар кремни , марганца и железа.In the process of melting such a mixture based on manganese slag, low-melting liquid mobile cupola slags quickly form, wetting the cast iron and protecting its surface from oxidation. At the same time, limestone distributed in a liquid base of cupola slag decomposes in a high temperature zone to release CO, which intensifies the spreading of the liquid base of the cupola slag on the exposed surfaces of the unprotected metal and thereby reduces flint of silicon, manganese and iron.

Claims

The sulfur content in the pig iron is reduced, and not only due to a decrease in its quantity coming from the limestone, but primarily due to the formation of slag with a higher absorbing capacity than in the known method, which, in combination with the increased wettability of this slag of liquid iron, promising application of the method and the use of cupola fuel with a high sulfur content. The noted effects, as well as an increase in the temperature of the iron on the trough, caused by the replacement of a part of lime with manganese slag, together contribute to an increase in the casting and mechanical properties of the iron and markedly reduce the number of scrap castings. The optimum ratio of manganese slag and limestone is 1:: (0.25 - 2.5), since with a larger proportion of manganese slag, the noted effects remain almost at the same level, and some, and especially the lining quality of the cupola, decrease. An increase in the proportion of limestone above this is accompanied by a deterioration in remelting rates — an increase in silicon and manganese loss, an increase in cast rejects, etc. The optimum amount of the mixture is 3–6% of the weight of the metal charge. With less soda, the achieved performance decreases, with a larger increase in coke consumption and reduced productivity of the cupola. An example of the method. In a cupola with the remelting of cast iron of the same composition, 50% of foundry coke was replaced with thermoanthracite having a higher sulfur content (up to 1.75%), and limestone was replaced with a mixture of manganese slag and limestone, taken in a ratio of 1: (0.20 - 2.5). The amount of the mixture is 2 - 7%. The temperature of the cast iron at the outlet increased to 1380-190 ° C. Silicon carbon monoxide, as compared with the known method, has decreased by 70%. Manganese carbon monoxide decreased by 70-85%. Accordingly, the amount of ferrosilicon and ferromanganese added to the metal charge decreased. The sulfur content in the castings decreased to 0.08 - 0.10% using the flux mixture in the ratio of 1; (2.0 - 2.50) and up to 0.06 - 0.07% of sulfur in the flux mixture with a ratio of 1: (0.20 - 1.0). Cast marriage decreased by 18%. Thus, smelting iron for castings in cupolas with a mixture of manganese slag and limestone instead of limestone makes it possible to significantly improve the quality of the iron and the technical and economic indicators of smelting. The invention of the method for producing pig iron in a cupola, including the introduction into the cupola of metal and flux containing limestone, followed by heating and melting, characterized in that, to increase the temperature of the iron and the quality of the castings, slag from the production of manganese ferroalloys, taken in relation to limestone, equal to 1: (0.25 - .2.5), and their total amount is 3 - 6% by weight of the metal charge. Sources of information taken into account during the examination 1. Pivovarsky E. High-quality cast iron. M., 1965, t. 11, p. 959.