RU2282673C2 - Method of production of ferro-titanium alloy - Google Patents

Abstract

FIELD: metallurgy; production of doping alloys.

SUBSTANCE: proposed method includes aluminothermic melting; burden is charged in crucible by layers: lesser part of burden and titanium waste is loaded underneath and larger part of burden is loaded above it. Prior to performing aluminothermic melting, admixtures are removed by creating vacuum in crucible at rarefaction below 20 mm Hg at preliminary heating of burden and titanium waste to temperature of 100-300°C. Proposed method makes it possible to use titanium chips contaminated with emulsion.

EFFECT: reduced melting losses of titanium; reduction of gas admixtures in finished alloy.

5 cl, 1 tbl

Description

The invention relates to the field of metallurgy and can be used to obtain alloying alloys.

A known method of producing ferrotitanium, including pressing from shavings of titanium alloys and iron shavings of a consumable electrode, which is melted in a vacuum arc water-cooled mold / RF Patent No. 21117067, 1998 /.

However, pressing a consumable electrode from titanium alloy chips is a difficult task.

There is also a method of producing ferrotitanium, including melting in a vacuum induction furnace shavings of titanium alloys and iron shavings / RF Patent No. 2118992, 1998 /.

To implement the method, an expensive furnace is necessary and it is difficult to supply chips to the furnace. The use of chips contaminated with emulsion leads to a sharp increase in carbon in the alloy (up to 0.6-1.2% at a rate of 0.3%).

The closest analogue is a method for producing ferrotitanium, including the preparation of waste from titanium and a mixture consisting of a material consisting of iron oxides and powdered aluminum, for aluminothermic melting / ed. testimonial. USSR No. 1418345, C 22 C 33/04, 1988 /.

Melting is carried out in an open atmosphere, with a large fume of titanium and a high content of gas impurities in the finished alloy.

The invention is aimed at reducing fumes of titanium and the content of gas impurities in the finished alloy.

The invention is also directed to the use of titanium chips contaminated with emulsion.

In addition, the invention is directed to the complete remelting of titanium shavings and the production of a monolithic ingot of ferrotitanium of a given chemical composition.

A method for producing ferrotitanium is provided, including the preparation of waste at least partially consisting of titanium and a mixture consisting of a material at least partially consisting of iron oxides and powdered aluminum for aluminothermic melting.

The selection of the chemical composition of the materials that make up the mixture, allows you to get a given chemical composition of the ingot, taking into account the balance of the generated and absorbed heat.

For aluminothermic melting, they are loaded into a crucible, the walls of which, in contact with the charge, are made of cast iron.

The materials are loaded into the crucible in layers, respectively, from below — the smallest part of the charge, titanium waste, then the majority of the charge, and impurities are removed before aluminothermic melting by creating a vacuum in the crucible with a pressure below the dew point. It is proposed to create a vacuum below 20 mmHg when preheating to a temperature of 100-300 degrees of charge and titanium waste.

The method can be implemented in the crucible installation for obtaining ligatures according to the patent of the Russian Federation No. 2058514, equipped with a liquid ring pump with an ejector for pumping vapors. The inner surface of the crucible chamber must be made of cast iron.

Waste in the form of chips of titanium alloys is crushed in jaw or ball crushers to a particle size of 1-100 mm.

As iron oxides, iron oxide or iron ore is used.

A preferred embodiment of the method.

The method of production (ferrotitanium involves the preparation of chips of titanium alloys contaminated with emulsion (waste consisting partly of titanium)) by grinding in jaw crushers to a particle size of 1-100 mm.

A crucible is used in contact with the charge and shavings, the walls of which are made of cast iron and the chamber cavity of which is connected to the ejector of the liquid ring pump to create a vacuum.

The mixture for aluminum-thermal melting of titanium consists of iron oxide and powdered aluminum.

In the crucible, layers are loaded respectively from below - the smaller part of the charge, shavings, then most of the charge and ignition device.

Close the crucible lid. The water ring pump is turned on with an ejector to create a vacuum of 10 mm Hg during preliminary heating to a temperature of 150 degrees of the charge and titanium waste chips with electric heating elements.

Initiate an ignition device.

The mixture is ignited and an exothermic chemical reaction occurs, as a result of which ferrotitanium and slags are formed.

During melting, the pressure inside the crucible rises, but does not exceed atmospheric pressure.

Upon cooling, crystallization of ferrotitanium occurs in the lower part of the crucible.

The melted ingot tray is lowered and set aside for unloading. Slag is knocked out in an auxiliary vessel for withdrawal beyond the crucible.

At this time, turn on the water ring pump using an ejector to remove dust from the cavity of the crucible chamber.

In industrial conditions, experimental smelting was carried out on an operating unit equipped with a vacuum system (table 1).

As a criterion for evaluating the effectiveness of the proposed method was taken: the chemical composition of the obtained ferrotitanium, the degree of penetration (assimilation) of the chips: the conditions for the separation of metal from slag.

The most effective indicators of the proposed method No. 1 is a more complete absorption of chips and higher titanium content in the alloy of ferrotitanium.

1) proposed;

2) 2 and 3 are beyond;

3) 4 for the prototype.

The results of experimental swimming trunks Experience Number Chip fraction,
mm Temperature ° С Vacuum mm. Hg Chip loading weight, kg The degree of assimilation of chips,% Carbon content Ecological result Fe-Ti Ti one 1-5 200 10 200 98 0.15 72 Purely 2 0-1 one hundred fifty 150 95 0.6 68 Purely 3 150-200 400 10 ^-1 one hundred 90 0.5 68 Purely four 150 twenty 760 one hundred 85 0.6 68 -

Claims (5)

1. A method of producing an alloy of ferrotitanium, including the preparation of waste at least partially consisting of titanium and a mixture consisting of a material at least partially consisting of iron oxides and powdered aluminum, for aluminothermic melting, characterized in that for aluminothermic melting is loaded into the crucible in layers, respectively, from the bottom — the smaller part of the charge, titanium waste, then the majority of the charge, and impurities are removed before aluminothermic melting by creating a vacuum in the crucible with a vacuum below 20 m Hg upon preliminary heating to a temperature of 100-300 ° C of the charge and titanium waste. 2. The method according to claim 1, characterized in that before loading into the crucible, titanium waste in the form of chips is crushed to a particle size of 1-100 mm 3. The method according to claim 1, characterized in that the crucible walls in contact with the charge are made of cast iron. 4. The method according to claim 1, characterized in that the waste uses shavings of titanium alloys. 5. The method according to claim 1, characterized in that the iron oxides are iron oxide or iron ore.