SU1219663A1 - Charge for melting low-carbon low-phosphorus ferromanganeses - Google Patents

Description

I

This invention relates to ferrous metallurgy, in particular to the production of ferroalloys.

The purpose of the invention is to increase the extraction of manganese and reduce the consumption of silicomanganese.

- This goal is achieved by the fact that the mixture containing lime, silicon Komargan and low-phosphorus slag, additionally contains ferrosilicon of the grade FS45 in the following ratio of components, wt.% :.

Lime36-38

Silikomanganese. 12-1D

Ferrosilicon

FS452-3 brands

Low phosphorus

slagEverything

The presence of iron in FS45 grade ferrosilicon has a positive effect on the thermodynamics and kinetics of manganese reduction. In the presence of iron, the reduction of manganese oxide is observed at lower temperatures and is determined by the formula T „8 DN (L3-5.575 Iga,

where U n is the change in the enthalpy of solution formation; d S - change in the entropy of the system, the activity of manganese in the system.

The lower limit of the content of ferrosilicon in the mixture is due to the fact that its introduction in an amount less than

2% by mass is not enough to increase the recovery of manganese. The introduction of ferrosilicon in an amount of more than

3% by mass leads to a loss of productivity due to a decrease in D.OI of manganese introduced with silicomanganese.

In ferrosilicon, the preferred ratio of the content of silicon and iron should be 0.7-0.8. Such a relationship takes place for FS45 grade ferrosilicon, having the following 20

19663J

its chemical composition, wt.%: silicon 41-47; sulfur 0.02; phosphorus 0.05; aluminum 2.0; iron 50-55.

The limits of the content of other components were established taking into account the consumption of ferrosilicon and ensuring the conditions for the process of reduction of manganese oxide.

Example. Under laboratory conditions on the Tamman furnace, under identical conditions, a comparative analysis of the mixture of the composition and the known composition is carried out. The tested mixtures of the mixture differ from one another by the content of ferrosilicon.

The composition of the mixture and the results of laboratory tests are given in table. one.

The chemical composition of the alloys of the proposed charge and known are given in table. 2

The use of the proposed mixture allows reducing the consumption of silicomanganese by 14-17%, increasing the extraction of manganese by 1.5-2.2% (abs.) And the weight of melting by 3-4%.

According to industrial experience, the use of the proposed composition of the charge makes it possible to increase the extraction of manganese by 3-5% (from 62.0 to 67%), to reduce the specific consumption of electricity and charge materials by an average of 4-6 and 6-8%, respectively, to increase the productivity of the furnace by 1-2%. In addition, the cost of the resulting alloy is reduced.

The obtained qualitatively new type of ferroalloy with an iron content of up to 10-12%, and the remaining elements at the level of GOST requirements for the MP2 grade under industrial conditions, shows a complete interchangeability of the scarce metallic manganese, moreover, the cost of steel decreases and the degree of manganese assimilation increases by reducing its concentration in ferroalloy and its melting point decrease.

25

thirty

35

40

45

Ferrosilicon brand

FS 45

Extraction of manganese,%

Mp content in waste slag,%

Average melting weight,%

Ferromanganese FMNO, 5 85

0.5

Ferromanganese

of the proposed charge

85

0.2

Compiled by O. Veretennikov Editor V. Petrash Tehred I. Polovych; Proofreader V.Sinitska

Order 1236/37 Circulation 567 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, Proektna St., 4

Table 1

12345 62.5 63.7 65.1 66, V 67.5

15.2 14,514.0 13,813,5

100.4 103104 102100

Table 2

The rest is 0.3

1.8

12

0.07

Claims (1)

Batch for smelting low-carbon low-phosphorus ferromanganese containing lime, silicomanganese and low-phosphorus slag, characterized in that, in order to increase manganese extraction and reduce the consumption of silicomanganese, it additionally contains ferrosilicon grade FS45, in the following ratio: wt% of components, wt. Lime36-38 Silicomanganese 12-14 Ferrosilicon brand FS45 2-3. Malophosphorous slag The rest and СО σ * CO> * 1219663