RU2356962C2 - Processing method of metallic chips of titanium subgroup and its melts - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: invention relates to metallurgy field, particularly to processing method of metal chips of titanium subgroup and its alloys. Method includes defatting of chips in water solution of washing material, flushing in hot water, drying and iodide refining with receiving of rod of fine metal. Additionally before defatting initial chips are crushed. After drying it is dispersed on grid with cell size 2-5 mm. Cut more than 2-5 mm is subject to iodide refining, and the rest after iodide refining chips are cleaned by washing in hot water or solution of washing material. Then it is dried, disseminated on grid with cell size 2-5 mm. Cut more than 2-5 mm together with initial chips of cut more than 2-5 mm is subject to iodide refining. ^ EFFECT: decreasing of laboriousness and metallic yield increasing during the chips processing ensured by reduction of operation labour-intensiveamount and cost saving of final product - iodide metal. ^ 4 cl, 1 tbl, 1 ex

Description

The invention relates to the field of metallurgy of metals of a subgroup of titanium and their alloys and can be used in the processing of chips by the method of iodide refining.

In the process of manufacturing products from metals of the subgroup of titanium and their alloys, a large number of large twisted chips with a width of up to 10 mm and a length of up to 1000 mm are formed, the oil content in such chips is 0.05-0.20% wt. This shavings refers to production waste and is currently being stored due to the lack of processing technology.

A known method of processing zirconium chips (RF patent No. 2238171, publ. 20.10.2004), including degreasing chips in an aqueous solution of detergent, washing in hot water, degreasing in an ultrasonic bath in an aqueous solution of detergent, washing in water, drying, grinding chips , pressing it into a briquette, remelting the briquette into an ingot, processing the ingot into shavings, which are subjected to iodide refining.

The disadvantages of this method are:

1. The impossibility of degreasing large twisted shavings, because due to the large volume of chips, it cannot be loaded into existing degreasing equipment and into the iodide refining apparatus.

2. The high cost of processing chips due to the need for an expensive operation of remelting it into an ingot and cutting chips before the iodide refining process.

The proposed invention solves the problem of processing large twisted shavings - increasing the yield of metal in the process of processing and reducing the cost of the final product - bars of iodide metal.

The technical result is achieved by the fact that in the method of processing metal chips of a subgroup of titanium and their alloys, including degreasing chips in an aqueous solution of detergent, washing in hot water, drying and iodide refining to obtain a bar of pure metal, before degreasing, the initial chips are crushed, and after drying scattered on a grid with a mesh size of 2-5 mm, a fraction of more than 2-5 mm is subjected to iodine refining, and the chips remaining after iodide refining are cleaned by washing in hot water or by washing with a solution its means are dried, scattered on a grid with a mesh size of 2-5 mm, a fraction of more than 2-5 mm, together with the initial shavings of a fraction of more than 2-5 mm, is again subjected to iodide refining.

It is preferable to degrease the initial chips with a detergent solution with a concentration of 0.005-0.015 kg / l at a solution temperature of 50-65 ° C for at least 8 minutes.

Before iodide refining, the initial chips of a fraction of more than 2-5 mm can be mixed with the remaining chips of a fraction of more than 2-5 mm remaining after the iodide refining process in a ratio of 1: (1-2).

To further increase the yield due to waste processing, fraction shavings of less than 2-5 mm can be pressed into briquettes, which are then welded into an electrode and melted into an ingot, from which chips are cut, cleaned by washing in hot water or a detergent solution, and dried and scattered on a grid with a mesh size of 2-5 mm, and subjected to iodine refining.

Grinding coarse twisted chips before degreasing them in combination with sieving and iodide refining of a fraction of 2-5 mm allows it to be processed using the iodide refining method without the use of costly operations of smelting and cutting chips from it, which significantly reduces the cost of chip processing and, accordingly, the cost of the final product.

Using a fraction of more than 2-5 mm for the iodide refining process can increase the yield of metal in the iodide refining process, since the fine chips during the process wakes up through a grid that holds the chips in the iodide refining apparatus, and enters the metal bar. In the process of sorting out finished products - bars of iodide metal, metal with shavings is characterized as scrap by inclusions, is cut down and goes to waste.

In the process of iodide refining, the chips loaded into the apparatus are not fully developed, 60-62% of the chips remain after the process, and its surface is contaminated with a dark coating, studies of which have shown that it consists of metal hydroxide. The presence of this plaque on the chips does not allow it to be processed by the iodide refining method. The use in the claimed technical solution of the operation of cleaning the remaining chips in hot water or detergent, sieving on a grid with a mesh size of 2-5 mm and repeated iodide refining of the chip fraction of more than 2-5 mm also contributes to an increase in yield.

Oil chips must be degreased before being subjected to iodide refining, as a high oil content leads to a decrease in the quality of the iodide metal due to the increased carbon content. The oil content in large twisted chips is small - 0.05-0.20% wt., Which allows it to be degreased in the detergent solution according to the following modes: the concentration of detergent in the solution is 0.005-0.020 kg / l at a solution temperature of 50-65 ° С , degreasing time - at least 8 minutes. This degreasing mode reduces the consumption of detergent and instead of steam to use hot water to heat the solution, which significantly reduces the cost of the operation of degreasing chips without reducing the quality of the finished product. Ultrasonic degreasing is not required to clean this chip.

To verify the claimed technical solution, the following work was carried out.

Example

Chips of titanium alloy VT-1-0 were processed, which was formed during various operations of manufacturing pipes, rods, billets and other products of rolling production. This shavings cannot be degreased, as suggested by the closest method, because it is very voluminous, up to 1000 mm long, and is not included in the loading device of existing equipment. Therefore, the chips were crushed in a chip mill and loaded into the chip washing unit. The chips were degreased in an aqueous solution of detergent SM-37 according to TU 6-52265324-99. It is possible to use other detergents with a similar degreasing ability, for example, Labomid-102 according to TU 6-002004843-29-95. Then the chips were dried and scattered on a screen with different mesh sizes. The chips remaining on the grid during sieving (initial) were loaded into the C-40 apparatus and subjected to iodine refining.

Unreacted chips discharged after the iodide refining process were cleaned in a rotating drum in hot water or a detergent solution, where, due to friction of the chip particles against each other, the surface of the chip contaminated with hydroxide was cleaned. Then this shavings were dried and dispersed on a screen with different mesh sizes of 2-5 mm, and then the shavings remaining on the grid were loaded into the iodide refining apparatus, while the raw materials for iodide refining were a mixture of the initial shavings and shavings after the iodide refining process.

In one embodiment, the fine chips that woke up through the mesh were pressed into briquettes, the briquettes were welded into an electrode, and the ingot was smelted by vacuum-arc remelting. Shavings were cut from the obtained ingot, which were degreased, dried, scattered on a screen, and the chips remaining after sieving were processed with iodide refining.

In the process of this work, the following parameters were varied.

1. When degreasing chips

- the concentration of detergent in water is 0.004; 0.005; 0.009; 0.011; 0.013; 0.015; 0.016 kg / l;

- temperature 45, 50, 55, 60, 65, 70 ° C;

- the duration of degreasing 6, 7, 8, 10 minutes.

2. When sifting chips on a screen

- mesh cell size 1, 2, 3, 5, 6 mm.

3. During the process of iodide refining of chips

- the ratio when loading into the apparatus C-40 of the original chips to the remaining unreacted chips remaining after iodide refining 1: 0.9; 1: 1; 1: 1.6; 1: 2.0; 1: 2.1.

For the work, the most contaminated shavings with an oil content of 0.20% by weight were selected. In the process of this work, the carbon content in the iodide metal was determined to assess the quality of chip degreasing and the metal yield of the entire chip processing cycle to obtain the iodide metal and the cost of the finished product, the iodide metal, were calculated. In this case, the yield of metal and the cost of metal according to the technical solution taken as a prototype was taken as 100%.

Analysis of the results shown in the table shows that the inventive method for processing chips of refractory metals and alloys of the titanium subgroup differs from the prototype in higher yield of metal obtained in the process of processing chips. So, the yield of metal according to the claimed method is 145.2-154.1%, and the cost of the finished metal is 72.6-73.4% instead of 100% of the prototype.

The optimal parameters for processing chips of the claimed technical solution are as follows:

- the concentration of detergent in an aqueous solution of 0.005-0.015% wt. (op. No. 17, 18, 21, 22, 25-28, 32, 33, 35, 36, 38, 39, 41, 42, 44, 46-48);

- the temperature of the solution is 50-65 ° C (op. No. 17, 18, 21, 22, 25, 26, 32, 33, 35, 36, 38, 39, 41, 42, 44, 46-48, 55-65) ;

- degreasing time - at least 8 minutes (op. No. 17, 18, 21, 22, 25, 26, 32, 33, 35, 36, 38, 39, 41-46, 48, 50, 52, 54, 55- 65);

- sieving chips on the grid with a mesh size of 2-5 mm (op. No. 56, 58, 60-66);

- the use for iodide refining of a mixture of a mixture of the initial chips of a fraction of more than 2-5 mm and chips after iodide refining of a fraction of more than 2-5 mm in a ratio of 1: (1-2) (op. No. 61, 62, 63, 65-68).

A decrease in the concentration of detergent in an aqueous solution (op. No. 2-10) leads to incomplete degreasing of the chips and an increased carbon content in the final product.

The increase in the concentration of detergent in an aqueous solution of more than 0.015% wt. (op. No. 49-54) practically does not lead to an increase in the degree of degreasing of chips, but causes an increase in the cost of processing chips due to an increase in the cost of detergent.

Reducing the temperature of the degreasing solution below 50 ° C (op. No. 2-5, 11-14, 29) leads to incomplete degreasing of the chips and contamination of the finished product with carbon.

An increase in the temperature of the degreasing solution above 65 ° C (op. Nos. 27, 28, 47, 48, 53, 54) practically does not lead to an increase in the degree of degreasing of the chips, but causes an increase in the cost of processing chips due to an increase in energy costs for heating water.

Reducing the duration of degreasing less than 8 minutes leads to incomplete degreasing of the chips and contamination of the finished metal with carbon (op. No. 15, 16, 19, 20, 23, 24, 30, 31, 34, 37, 40, 45).

Sieving chips on the grid less than 2 mm leads to an increase in the amount of rejected metal, which reduces the yield of metal (op. No. 55).

Sieving chips on a mesh with a mesh of more than 5 mm significantly increases the number of screenings that require additional processing, which increases the cost of the final product (op. No. 59).

Using for a iodide refining of a chip a mixture of the original chip of a fraction of more than 2-5 mm and the remaining fraction of an unreacted chip of a fraction of more than 2-5 mm in the ratio of less than 1: 1 remaining after iodine refining leads to an increase in the time of the iodide refining process, because the cleaned chip is easier subjected to iodide refining, which increases energy consumption and leads to an increase in the cost of the final product (op. No. 60).

Use for iodide refining of the mixture of the initial chip fractions of more than 2-5 mm and the remaining fraction after the iodide refining of the chip of more than 2-5 mm in a ratio greater than 1: 2 leads to an increase in the number of processing cycles of the original chip and ultimately to an increase in the complexity of the process and rise in price of final products (op. No. 64).

The inventive method was tested with positive results in a production environment and allowed to process the shavings of titanium alloy VT-1-0, formed in the rolling industry in the manufacture of products from this alloy, and is still stored in the warehouse. According to this method, 780 kg of titanium alloy chips were processed.

The inventive method according to the same method with identical positive results was tested in the processing of shavings of zirconium alloys E110 and E125 formed in the manufacture of products from these alloys, as well as hafnium grade CTG (calcium thermal hafnium) in order to obtain a cleaner metal grade GFI (hafnium iodide ) 1,500 kg of chips of each zirconium alloy and 450 kg of hafnium chips were processed.

Claims (4)

1. A method of processing metal chips of a subgroup of titanium and their alloys, including degreasing chips in an aqueous solution of detergent, washing in hot water, drying and iodide refining to obtain a bar of pure metal, characterized in that before degreasing, the original chips are crushed, and after drying scattered on a grid with a mesh size of 2-5 mm, iodide refining is subjected to a fraction of more than 2-5 mm, and the chips remaining after iodide refining are cleaned by washing in hot water or a detergent solution, dried, scattered on a grid with a mesh size of 2-5 mm, and a fraction of more than 2-5 mm, together with the initial chips of a fraction of more than 2-5 mm, are subjected to iodine refining. 2. The method according to claim 1, characterized in that the degreasing of the original chips is carried out with a detergent solution with a concentration of 0.005-0.015 kg / l at a solution temperature of 50-65 ° C for at least 8 minutes. 3. The method according to claim 1, characterized in that before iodide refining, the initial chips of a fraction of more than 2-5 mm are mixed with the remaining chips of a fraction of more than 2-5 mm remaining after the iodide refining process in a ratio of 1: (1-2). 4. The method according to claim 1, characterized in that the initial chip obtained after sieving of the fraction of less than 2-5 mm is pressed into briquettes, the briquettes are welded into an electrode and melted into an ingot from which the chips are cut, cleaned by washing it in hot water or a washing solution means, dried, scattered on a grid with a mesh size of 2-5 mm, and chips of a fraction of more than 2-5 mm are subjected to iodine refining.