SU724587A1 - Metallurgical slag stripping charge - Google Patents

Description

(54) CHARGE FOR SUSPENSION OF METALLURGICAL SLAGS

The invention relates to the processing of nonferrous metallurgy slags by treating the melt with depleting mixtures and can be used to extract non-ferrous metals from slags from nickel, copper-smelting and other industries. The known mixture for the depletion of metallurgical slags containing ka oxide, sulfide material and iron alloy l. The disadvantage of the charge lies in the fact that it does not provide sufficiently complete extraction of metals from the slag. The aim of the invention is to increase the utilization of sulfur and the extraction of non-ferrous metals. The goal is achieved by the fact that the mixture contains ingredients in the following ratio, weight. %: Calcium Oxide 5-30 Sulg} P1 forma matorp; 15-7О Jaw.ch11st (.1y dslpvSKH talnyu kaaktsia oxide content in the mixture. The result of the decrease in electrical conductivity of the charge to values comparable to the electrical conductivity of the depleted slag melt. The optimum content of calcium oxide in the mixture, according to the integrated tests, is found. -30% of the weight of the charge. A higher content of oxides of Kalysh (over 30% ZO) is unjustified due to an increase in slag yield and loss of non-ferrous metals. When the calcium oxide content in the mixture is up to 5%, the electric curvature of the mixture remains much higher cm cm), and when its content is more than 30% 1% (less O, Yum-cm) than the electrical conductivity of the slag-melt, which in both cases leads to a disruption of the electric melting mode. Calcium oxide should be introduced into Znhta as complex Associated with, for example, sulfates, calcium sulfate and calcium carbonates, natural minerals (limestone, dolomite, gypsum, etc.), industrial intermediates and wastes (limestone, phosphogysis, etc. .) The content of the iron-carbon alloy in the charge is determined as necessary. The degree of metallization of the resulting matte, the initial content of non-ferrous metals in the slag, is 20-70% of the weight of the charge for the depletion of slags. The recommended content of iron carbonaceous matter, as well as sulfide material, and their ratio is due to the need to produce mattes with a sulfur content of 15-30%, typical of non-ferrous metallurgy. A decrease in the content in the charge of the iron – carbon alloy of the alloy below 20% leads to a sharp increase in sulfur loss during the melting of the charge. When the iron content of the alloy in the charge exceeds 7 0%, an over-metallized matte with a high melting point is released, which will require a significant increase in the process temperature. The iron-carbon alloys use iron chips, a magnetic fraction of the calcine from the reduction of iron-containing materials, for example, oxidized nickel ores, zinc cakes, solid slag, etc. The content of sulfide material in the mixture is determined by the initial content of non-ferrous metals in the slag, the degree of metallization of matte and composition According to experimental data, 15-70% of the weight of the charge for the depletion of slags. The maximum content of sulfide material (7O%) in the charge is limited by an increase in sulfur losses and a decrease in nickel extraction, and its minimum content (15%) is an increase in the electrical conductivity of the charge (up to 0.3-0.40 m K: m) and electrical disturbance slag depletion regime. Pyrite, pyrite, sour metallurgical wastes and other high-sulfur materials can serve as a sulfide material. The bluntness of the charge components does not exceed 20–20 mm, preferably no more than 5–1 mm. The mixture can be pre-graded using spedding methods (pelletizing, (riking) and subjected to thermal processing (sintering, calcining, roasting). Processing of metallurgical slags with ihta can be carried out both on an electrically heated apparatus and in apparatus using other types of fuel (natural , generator gas, etc.). In addition, calcium oxide reduces the loss of sulfur into the gas phase during the thermal decomposition of the sulfide components of the charge, due to the convergence of sulfur into strong calcium sulfide. At the same time, Calcium sulphide is an active sulphidizer for non-ferrous metals in the slag, which contributes to the growth of non-ferrous metals in matte. The latter two effects (reduction of sulfur loss g by gases and non-ferrous metals with slag) retain their value when using the proposed blend for slag Only in electric furnaces with slag conductivity, but also in other well-known metallurgical aggregates. Example: In tests, a mixture composed of cast iron chips, pyrite and technical calcium oxide is used. The size of the components of the mixture in the range of 2-5 mm The electrical conductivity of the charge is determined by measuring the resistance of the layer of solid charge of a given thickness and cross-section in the temperature range up to 1 ° C. The mixture is tested for the depletion of slag mine smelting of oxidized nickel ores. The experiments are carried out in an electric furnace with a power of 80 kW lined with magnesite. Slag build-up is 30 kg. The slag is melted in an electric furnace and finished. d t melt temperature up to 128О13ОО. The mixture on the surface of the melt is fed through the loading opening in the furnace roof into the interelectrode zone. The consumption is 2.5% of the weight of the slag. After heating the mixture and assimilating it with the melt, the slag is constituted within 10-15 minutes. The temperature of the process is periodically controlled by an immersion tungsten-rhenium thermocouple. Then the slag and the resulting matte drank into the mold. After cooling, the products of melting are weighed and analyzed for the main components. The results of the exhaustion of the charge for the depletion of metallurgical slags are shown in the table.

The test results show that the introduction of calcium oxide in an amount of 5–30% into a mixture containing iron shavings and pyrite makes it possible to reduce the electrical conductivity of the charge by 2–4 times to deplete metallurgical slags and reduce it to slag melt. At the same time, the nickel reading is higher than 13.0 abs. % and losses to the gas phase are reduced by 5-10 abs. %

Thus, the mixture of the proposed composition for the depletion of metallurgical slags reduces the electrical conductivity of the mixture for the depletion of slags and stabilizes the operating mode of the electric furnace; reduction of noTqpb sulfur with gases; enhanced nickel to matte extraction.

15 f

formula of invention

The mixture for the depletion of metallurgical slags, containing calcium oxide, sulphide matte and ferrous alloy, is about the fact that, in order to increase the degree of utilization of sulfur to the non-ferrous metals recovery and the extraction of non-ferrous metals, the mixture contains the following ingredients, weight. %: Calcium Oxide 5-ZO

Sulphide material15-7 O

Ferrous alloy Else

Sources of information, u) are considered in the examination

1. USSR author's certificate No. 2O3236, cl. From 22 to 7/04, 1966.

Claims (1)

Claim The test results show that the introduction of calcium oxide in an amount of 5-30% in a mixture containing pig-iron shavings and pyrite can reduce the conductivity of the charge by 2-4 times to deplete metallurgical slag and bring it closer to the conductivity of the slag melt. In this case, nickel recovery is increased by 11.113.9 abs. %, and sulfur losses in the gas phase are reduced by 5-10 abs.%. Thus, the mixture of the proposed composition for depletion of metallurgical slag provides a decrease in the electrical conductivity of the mixture for depletion of slag and stabilization of the operating mode of the electric furnace; reduction of sulfur losses with gases; increased nickel extraction in matte. A mixture for depletion of metallurgical slag containing calcium oxide, sulfide material and a ferrous alloy, characterized in that, in order to increase the degree of use of sulfur and increase the extraction of non-ferrous metals, the mixture contains in the following ratio, Calcium oxide Sulfide material Ferrous alloy ingredients weight. %: 5-30 15-70 Rest