SU1693080A1 - Charge for melting modifiers with rare-earth metals - Google Patents

Abstract

The invention relates to blend compositions for smelting modifiers with rare-earth metals. The aim of the invention is to expand the technological capabilities by increasing the deoxidizing, desulfurizing and dephosphorizing abilities of the modifiers and reducing the cost due to the use of secondary resources. The mixture contains, wt%: sludge from the electrolytic production of rare-earth metals 22-31; screenings for the preparation of recycled aluminum raw materials 37-45; powder-type limestone quarry waste 1.5-3.0; screening of enriched dolomite 5-10, calcium fluoride 0.5-1.0; sludge production mzoganets electrolytic dioxide 16.5-26.0. Processing with modifiers smelted from the proposed alloy of steel and cast iron indicates an increase in the deoxidizing, desulfurizing and dephosphorizing ability of the modifiers, the degree of extraction of components from the melt. The cost of 1 ton of the charge is 400-440 rubles. 2 tab.

Description

The invention relates to ferrous metallurgy, in particular to the smelting of modifiers for the production of high-strength cast iron and high-quality steel.

The aim of the invention is to expand the technological capabilities by increasing the deoxidizing, desulfurizing and dephosphorizing abilities of modifiers and reducing the cost due to the use of secondary resources.

Example. Several compositions were prepared, the mixture, from which modifiers with rare-earth metals (REM) were smelted. The fractional composition of all charge materials was taken in the form in which they are obtained during the main production, f.e. without additional processing. At the same time, the fractional composition of sludge from electrolytic production of rare-earth metals, powdered limestone quarry waste, sludge from manganese dioxide production amounted to 5 mm, and screenings for the preparation of secondary aluminum raw materials - up to 8 mm.

The chemical composition of the charge materials is as follows.

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Slurry of electrolytic production of rare-earth metals, wt.%: The sum of oxides of rare-earth metals 35,0; The amount of chlorides of rare-earth metals 10.0; CaCte 25.0; KCI 10.0; Cao rest.

REM-containing sludge from the electrolytic production of rare-earth metals is a waste from the production of rare-earth metals by the electrolysis of rare-earth metals, which remains in the electrolyzers.

The screenings for the preparation of secondary aluminum raw materials have the following composition.

Elimination of aluminum chips (TU 48-26- 52-82), wt.%: AI 40-55; Si 5.6; Mg 0.35; Zn 1.9; N 1,2; Mn 0.26; Fe 14-15; oxides of Fe, A, and other elements else.

Metallurgical yield of 55-40%, size not more than 3 mm.

Waste screening recycled aluminum raw materials, wt.%: AI25-30; SI 6.2; Mg 0.8; Zn 0.8; Ni 0.87; Mn 0, f5; Fe 15-18; oxides of Fe, AI and other elements else.

Metallurgical yield 25-30%. Content class minus 0.1 mm 15-20%.

The waste screening of recycled aluminum raw materials is not satisfactory to TU and represents a sub-standard waste screening of recycled aluminum raw materials.

Powder waste limestone quarry, wt.%: SI02 0,60; CaO 84.00; MDO 0.62; 1.38; Fe 0.57; P 0.067; ppt rest.

Limestone mined in a quarry is used in sintering, blast furnace, steelmaking and ferroalloy production processes. In this case, according to OST, the particle size should be in the range of 5-30 mm, and the production of fluxed agglomerate should be up to the class of 0-3 mm.

Powdered waste - lime, mainly containing less than 1 mm. Such limestone, which does not satisfy the conditions of OST and does not have technical conditions, is a waste of a limestone mine.

Sludge from the production of electrolytic manganese dioxide (EDM), wt.%: Mp 20.50 - 26.0; SI02 20-21.4; Mn02 8.3; CaO 4.80; NI 0.20; ReaOz 3.40; A1203 4.60; MgO 1.20; P 0.30; sulphides and oxides of other elements else.

The elimination of burnt dolomite, wt.%: SI02 2,00; ABOz 2.0; ReaOz 0.30; MDO 36.0; CaO 55.0; NaO 2.20; COA 2.50.

Natural dolomite is burned in drum furnaces, scattered after firing, a fraction of more than 3 mm is used in metallurgical production, and a fraction of less than 3 mm does not have a specification and is called sintering of burned dolomite.

Materials prepared for smelting were poured into the hoppers of the dosing device, from where they were fed to the measuring device using feeders or by gravity, mounted on the scales, weighed materials were fed to the mixer, where the mixture was mixed for 5-10 minutes. Thoroughly mixed

The charge was poured into a graphite crucible of an ICT-type induction furnace. The crucible was previously heated to 1000-1050 ° C, after filling the crucible with the charge, the furnace was disconnected from the power source, after 5-7 minutes it began to recover and melt. The exothermic reduction and smelting process lasted an average of 17 minutes; at the time the exothermic process subsided, the furnace was re-connected to the network to maintain the temperature in order to average the chemical composition and completely separate the metal and slag. This period lasted no more than 14 minutes. At the end of the process of finishing the alloy with slag was kept in

0 hot metal at 1350-1400 ° С. The whole process from the moment of loading the charge into the crucible to the loading of the new portion lasted 36-38 minutes.

After the alloy cooled down, the chill mold was turned over, the ingot easily fell out of the chill mold,

5 the surface of the alloy was clean. The slag layer on the upper part of the modifier ingot is easily separated from the latter without machining. The output of the alloy is 46-52%.

The chemical compositions of the proposed and known charge, as well as the modifier are given in Table 1.

Smelted modifiers were used in the smelting of iron and steel.

The steel was melted in an induction furnace with a capacity of 1 ton. The steel melt was released5 into the casting ladle at 1620-1650 ° C. Before steel production, a modifier was loaded into the ladle at a rate of 1% by weight of steel.

Cast iron was melted in an induction furnace with a capacity of 1 t. Molten iron was released from a furnace at 1330–1350 ° C into a ladle; before being released, a modifier obtained from the proposed and known charge was loaded into the ladle, the flow rate of the modifier was

5 1% by weight of cast iron.

The chemical composition of the steel before processing, wt.%: C 0.41; Mp 0.58; Si 0.32; S 0.04; P 0.037; AI, REM, Ca and Mg are absent. The chemical composition of the pig iron before processing,

0 wt.%; C 3.2; Si 0.82, Mp 1.2; S 0.017; P 0.18; AI, REM, Ca and Mg are absent.

The results of the processing of steel and cast iron modifier held in table 2.

How should published, submitted

5 in Tables 1 and 2, the invention makes it possible to increase the deoxidizing, desulfurizing and dephosphorizing abilities of modifiers, thereby expanding the technological capabilities of modifiers,

which are used in the processing of iron and steel. In addition, the cost of the charge is significantly reduced through the use of secondary resources.

Claims (1)

Claims for smelting modifiers with rare-earth metals, containing REM-containing materials, aluminum-containing materials, calcium-containing fluxes, magnesium-containing materials, and calcium fluoride, in order to expand technological capabilities by increasing races of acid desulfurizing and dephosphorizing abilities of modifiers and cost reduction due to the use of secondary resources, it contains electrolytic sludge as a REM-containing material. production of rare-earth metals, as an aluminum-containing material - screenings for the preparation of secondary aluminum raw materials, as calcium-containing flux - powdery waste of limestone quarry, as magnesium-containing material - sifting of burnt dolomite and additionally sludge from the production of electrolytic manganese dioxide in the following ratio, wt.%: Sludge electrolytic production of rare earth metals22-31 Screenings for the preparation of secondary aluminum raw materials 37-45 Powdered waste limestone quarry 1,5-3,0 Screened baked dolomite5-10 Calcium fluoride 0.5-1.0 Slurry production of electrolytic manganese dioxide16,5-26,0 but t AND 26 l W 37 40 2.5 3 1.5 7.3 250.5 260.7 16.5 1 1 ", 5:, 5 2-3 3.0 13 15 and 26 4 is 2 12 723.5 5.3 22 Rest five 13 15 12,5 38