SU1747503A1 - Charge for melting low-phosphorus manganese slag - Google Patents

Abstract

Use: production of pig manganese slag for smelting low-phosphorous manganese ferroalloys. The essence of the invention: The charge for melting low-phosphorous manganese slag contains, in wt.%: Manganese sinter 94.2-94.8; anthracite shtyb 1,2-5,88 and coke the rest. The use of the charge makes it possible to reduce the phosphorus content in the slag by 10–15%, to increase the extraction of manganese in the slag by 2.6–4.7%: 1 table.

Description

FIELD OF THE INVENTION The present invention relates to ferrous metallurgy, in particular, to the production of pig manganese slags for smelting low-phosphorous manganese ferroalloys.

The known charge for smelting low-phosphorus manganese slag (MFS) is a continuous process with the following ratio of components in the ore-settling mixture, May%:

Manganese sinter 95-94;

Coke 5-6.

The main technical task in smelting MFSH is a more complete recovery of phosphorus from manganese raw materials with minimal reduction of manganese. From this position, the disadvantage of the prototype is the use of a carbonaceous reducing agent with high carbon activity, which leads to a decrease in the quality of the FSM modulo phosphorus due to a decrease in the mass fraction of manganese in the low-phosphorus slag. Therefore, the subsequent metallurgical conversion will require an increased consumption of such low-phosphorus slag. It should also be noted that coke is an expensive and scarce material.

In pyrometallurgical dephosphorization using coke, the ratio of phosphorus to manganese in low-phosphorus slag is maintained at level 4 ,. Improvement of this index (its reduction) can be achieved with the use of a thermodynamically less active reducing agent. At the same time, manganese, which is a hardly-reducing element, will be reduced to a lesser extent and its content in low-phosphorus slag will increase. This effect is achieved with the use of anthracite shtyb, which is a by-product of coal mining and has lower carbon activity compared to coke.

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eight

with

The lometric composition is represented by a fraction of 0-6 mm.

The purpose of the invention is to improve the quality of slag and extract manganese in low-phosphorous slag.

This goal is achieved by the fact that the charge for smelting MFSH contains anthracite grit (C-68-73%. A-14.2-17.0%) in the following ratio of components in the mining mix, in wt.%:

Manganese sinter 94.2-94.8:

Anthracite Shtyb 1,2-5,8;

Coke Else

The lower limit of the content of anthracite ityba (1.2%) was determined taking into account the onset of a significant positive effect on the quality of the FSM,

The upper limit of the a1 content of the anthracite chuck charge (5.8%) corresponds to the complete replacement of coke with carbon. In this case, the phosphorus module in the mixture reaches a minimum. However, at the same time, the stability of current loads decreases due to the fine fractional composition of anthracite shtab, as a result of which the specific power consumption increases.

The optimal proportion of anthracite shtyb in the charge corresponds to 70-80% of coke replacement by carbon.

Example, MFSH melting was carried out in a 240 kVA large-laboratory furnace. As manganese raw materials used agglomerate brand AMNSH (42.5%

MP, 0.2% P). Restore carbon to manganese ore ratio in all variants were kept constant. Fluxing materials and iron shavings are not used. The release of metal and slag was carried out jointly into a cast-iron mold, after which the melting products were manually dismantled for their weighing and sampling for chemical analysis. For each option held 5 heats. The averaged results of the melts are shown in the table.

As follows from the above data, the use of the proposed composition of the charge made it possible to reduce the phosphorus modulus with a simultaneous increase in the extraction of manganese by 1.6–4.7%. A decrease in the specific energy consumption in comparison with the prototype by 17–33 kWh is associated with an increase in the manganese content in the slag. Some height

Claims (1)

Specific energy consumption in options 3 and 4 is due to the reduction of the carbon reductant size. Claims of the invention for smelting low-phosphorous manganese slag containing manganese agglomerate and coke, characterized in that, in order to improve the quality of the slag, extract manganese into a low-phosphorus slag, it additionally contains anthracite shtyb in the following ratio, wt%: Manganese sinter 9x}, 2-94,8; Anthracite Shtyb 1,2-5,8; Coke Else Table continuation