SU897876A1 - Covering refining flux for copper and its alloys - Google Patents

Description

one

The invention relates to non-ferrous metallurgy and is aimed at developing a refining flux for the treatment of copper and its alloys with protecting the metal from oxidation and removing non-metallic inclusions present in the alloy.

Known coating-refining flux for copper and its alloys 1.

Closest to the invention to the technical essence and the achieved result is with a coating flux for copper and its alloys, containing sodium chloride and fluorine C21.

A disadvantage of the known flux is the high content of sodium fluoride in it, which leads to increased environmental pollution by harmful components of NaF, increases the composition, increases metal losses due to its interaction with fluorides.

The aim of the invention is to improve the technological performance of the refining process and reduce the cost of flux.

This goal is achieved by the coating-refining flux for copper and its alloys containing sodium chloride and fluoride, contains components in the following ratio, wt.%:

ten

Fluoride

sodium

Chloride

Sodium Else

Claims (2)

Studies show that the melting temperature of mixtures varies from 785 to 725 C and, at liquid metal temperatures of 950-1050 C, the flux easily melts on the surface, forming a liquid salt layer protecting the metal from active oxidation. When the flux is mixed with the liquid metal, the salt phase is enriched with slurry inclusions (CuO, ZnO 3, etc.), and this demonstrates its refining effect. In addition, it is found that after the treatment of brass, the metal becomes more fluid, which is evidence of a decrease in slag inclusions in it. After treatment of liquid copper with the composition indicated, a decrease in the porosity of the castings and a decrease in the foundry scrap were established. The amount of flux injected is determined by the size of the surface of the liquid metal and the level of contamination by its slag inclusions. The optimum flux consumption rate is 0,, 0 by weight of the metal. The positive effect of the proposed flux for treating brass is also manifested in the fact that after it is applied to the surface of the alloy and melted, the number of zinc burnout centers is significantly reduced. It has been established that when the NaF content in the mixture is below 3, the slags are poorly moistened with saline, the technology of their separation from the metal surface is deteriorated. When the content of NaF is higher than 15, a more active interaction of the mixture with the liquid metal is noted, a stronger gas separation and deterioration of the slag separation conditions due to an increase in the fluidity of the mixture. The limits of NaF concentration from 3 to 15 should be recognized as optimal, they provide sufficient wettability of the slag salt phase and do not cause complications in the separation of the flux from the metal surface. Example 1.8 Reflective Melting Furnace loads 250 kg of brass, the metal is melted, the temperature is maintained at 950-980 seconds. Multiple ignition of zinc, actively evaporating and burning in air, is visually observed on the metal surface. On the metal surface, with a 2.0 kg salt mixture containing 3 NaF and 97% NaCl. The flux quickly melts, covering the metal with a layer of liquid salt phase, while moderate evaporation of the mixture is observed, and the number of zinc burnout centers is significantly reduced. After the flux is mixed with the metal, the slag is separated with a scraper. Received 2.3 kg of flux-slag mixture containing an average of analyzes 8-20; oxide compounds present in the metal and partially formed during oxidation during the smelting of the metal. The content of liquid brass in the slag varies from 2 to 8%. When casting an alloy into products, an increase in the fluidity of the alloy is qualitatively noted, which is achieved by reducing non-metallic (oxide inclusions) in it. Example 2. The amount of metal used for melting and its melting method is similar to Example 1. A liquid metal is coated with a layer of 7 % NaF and 97% NaCI, total amount 2.1 kg. Flux melts on the metal surface to form a liquid layer. Zinc burns out insignificantly. Slag contains up to 15 oxide compounds. Example 3. The amount of metal melted and its melting method is similar to Example 1. A liquid metal is coated with a flux consisting of 15 NaF and 85 NaCl. The total amount of flux introduced is 2.0 kg, CViecb quickly melts on the metal surface and after mixing it is settled. Slag contains up to 22% oxide inclusions. Metal fluidity increases. Due to the lack of available methods for determining the fluidity of brass at high temperatures, this property is assessed visually by the experience of the smelters. An example. 100 kg of copper are introduced into the induction heating furnace. After the metal is melted, 1.0 kg of a flux of composition 7% NaF and 93% NaCl are introduced and the metal is subjected to refining at. After removal of the slag, metal is cast into a chill mold. The metal is clean, does not contain visible slag inclusions. Flux clumping and violent gas evolution are not observed. Thus, the proposed composition effectively protects the metal from oxidation and has a refining effect in the process of smelting copper and its alloys. Considering the ease of preparation, the lack of hygroscopicity and the reduction of 58978 costs by 3-5 times compared with the known, the application of the invention in industry is expedient and cost-effective, Claim of the invention Cover-refining flux for copper and its alloys containing chlorine and sodium fluoride, which is due to the fact that, in order to improve the technological performance of the process of refining and cheapening the flux, it contains a compound (IS) 64 nenty in the following ratio, wt.%: sodium fluoride th Else Sources of information taken into account during the examination 1. USSR author's certificate No. 558952, cl. From 22 to 7/00, 1976. 2. Gorshkov I.E. Casting ingots of non-ferrous metals and alloys. L., - M., Chief editor of literature on non-ferrous metallurgy, 1937, p. 271.