RU2397261C1 - Procedure for processing copper-nickel mattes - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: invention refers to procedure for processing copper-nickel mattes. The procedure consists in pouring melt of copper-nickel matte and in charging flux. Also non-ferrous scrap containing iron is charged into a source melt of copper-nickel matte. Metallised matte is produced upon blowing with oxygen containing gas mixture and upon slag tapping. Upon slag tapping metallised matte is sulphidised with reduced gases of autogenous smelting containing sulphurous anhydride to contents of sulphur equal to sulphur contents in source melt. 40-60 % of finished sulphide product is further tapped, and operations are successively repeated. ^ EFFECT: maintaining contents of sulphur in copper-nickel matte. ^ 3 ex

Description

The invention relates to the field of non-ferrous metallurgy and can be used in the processing of non-ferrous scrap metal containing iron.

Known methods for converting copper-nickel mattes (A.V. Vanyukov, N.I. Utkin. Integrated processing of copper and nickel raw materials. Publishing House Metallurgy, 1988, 432 pp.), Which are aimed at improving the quality of the matte, increasing nickel recovery and cobalt, saving flux consumption, intensification of the conversion process, etc.

The disadvantage of these methods is the small number of processed cold additives containing iron.

Closest to the proposed invention in technical essence and the achieved result is the method (AS No. 897877, Method for converting copper-nickel mattes. Pub. 15.01.82. Bull. No. 2), including pouring the melt of copper-nickel matte, loading flux blowing an oxygen-containing gas mixture, draining the slag to obtain a metallized matte.

The disadvantage of this method is the limited number of added cold additives (non-ferrous scrap containing iron) and the iron content in them, because an increase in these parameters will lead to a sharp decrease in the sulfur content in matte, which makes it impossible to further process it.

The objective of the invention is to maintain the sulfur content in matte by introducing it in the form of reduced gases autogenous melts.

This is achieved by the fact that according to the claimed method for processing copper-nickel matte, including pouring a melt of copper-nickel matte, loading flux, purging with an oxygen-containing gas mixture, draining slag to obtain a metallized matte, non-ferrous scrap containing iron is loaded into the initial melt of copper-nickel matte , after the slag is drained, metallized matte is sulfidized by the reduced gases of autogenous smelting containing sulfur dioxide to a sulfur content equal to the sulfur content in the initial melt, and 40-60% of the finished sulfide product is drained, followed by repetition of the processing of non-ferrous scrap metal starting from the load.

Purging is used to maintain the temperature of the melt after loading non-ferrous scrap metal containing iron and transferring part of the iron to slag due to its oxidation and binding to fayalite with the addition of quartz sand flux. The sulfidation operation is carried out to compensate for the lack of sulfur in matte after dissolution of scrap metal, it is carried out by reducing sulfur with a carbon-containing reducing agent from autogenous smelting gases containing sulfur dioxide, according to the following main reactions (G. Eremin and others. Production of elemental sulfur from metallurgical gases for abroad., Vlasov OA and others. The use of reduced gases autogenous smelting for sulfidation of oxidized copper ores. Non-ferrous metallurgy. 1991, No. 5. P.25-26):

when using natural gas as a reducing agent and when using pulverized coal:

The amount of sulfur introduced into the melt is determined by the percentage of sulfur in the original matte. The maximum amount of non-ferrous non-ferrous scrap metal containing iron depends on the composition and can be determined from the expression:

where C _pc and C _m - heat capacity of matte and scrap metal, respectively;

_Pieces t, t _k, t ₀ - matte feed temperature, crystallization temperature and the temperature of the metal before loading, respectively.

After sulfidation, 40-60% of the finished sulfide product is poured, which can be processed further using standard technologies. The amount of 40-60% of the discharged finished sulfide product is determined by the optimal yield of the product, because when draining less than 40%, the melt mass will accumulate in the converter; when draining more than 60%, the melt mass will decrease with its subsequent solidification in the converter.

The method is illustrated by the following examples.

Example 1. The experiments were carried out in a furnace with silicon carbide heaters in alundum crucibles with a capacity of about 200 ml. In copper-Nickel matte composition (wt.%):

Cu — 15.3, Ni — 12.7, Fe — 50, Co — 1.2, S — 20.1, 30% non-ferrous scrap metal (wt%) was added: Ni ~ 50, Fe ~ 50. Purge was carried out. with an oxygen-containing mixture (air) through an alundum tube introduced into the melt from above, the temperature of the initial matte was estimated by formula 6, the fayalitic slag obtained by adding flux-quartz sand was poured, a sulfidation operation was carried out with a mixture of sulfur dioxide and dusty coke in a stoichiometric ratio according to the reaction ( four). The mixture was introduced into the melt from above through a long alundum tube with an inner diameter of 3 mm, which was buried into the melt by 20 mm.

After sulfidation, the matte composition (wt.%) Was obtained:

Cu - 11.1; Ni - 19.9; Fe - 47; Co - 0.87; S - 20.8; 40% of which was leaked for further processing.

Example 2. In matte of the same composition as in example 1, was added 25% non-ferrous scrap composition (wt.%): Ni≈30, Cu≈30, Fe≈40. After purging (purging and estimating the temperature of the matte was carried out in the same way as in example 1), the slag was drained (as in example 1) and sulfidized (the sulfidation process is the same as in example 1), the matte was obtained (wt.%) : Ni - 15.1, Cu - 17.2, Co - 0.92, Fe - 46.7, S - 19.8. Another 15% of the same scrap metal was added with repeated purging, slag discharge, sulfidation, after which 50% of the finished sulfide product was drained.

Example 3. In matte of the same composition as in example 1, 40% non-ferrous scrap metal of the composition (wt.%) Was added: Ni - 28, Cu - 30, Co - 2, Fe - 40. Purge (purge and estimate the temperature of matte) carried out in the same way as in example 1) with the discharge of slag (as in example 1), and then sulfidized (the sulfidation process is the same as in example 1) to the sulfur content in the original matte. 60% of the obtained matte composition (wt.%): Ni - 15.3, Cu - 17.1, Co - 1.2, Fe -45.8, S - 20.3, poured for processing.

Thus, the proposed method allows for semi-continuous processing of copper-nickel matte with the discharge of 40-60% of the finished sulfide product and the sulfur content in the matte.

Claims (1)

A method of processing copper-nickel matte, including pouring a melt of copper-nickel matte, loading flux, purging with an oxygen-containing gas mixture, draining slag to obtain a metallized matte, characterized in that non-ferrous scrap metal containing iron is loaded into the initial melt of copper-nickel matte after discharge the slag is sulphidized by metallized matte with reduced gases of autogenous smelting containing sulfur dioxide to a sulfur content equal to the sulfur content in the initial melt, and was 40-60% of the finished product, followed by sulfide repeating operations.