SU637443A1 - Method of processing fine-dispersed tin-containing materials - Google Patents

Description

The invention relates to the field of non-ferrous metallurgy, in particular to the field of processing of poor tin-containing raw materials.

A known method of processing finely dispersed tin-containing materials by foaming on a slag bath, including melting them with coke and sulfur • pyrites, purging with a mixture of air with a reducing agent, trapping tin * dust and reducing it by melting, which is the closest technical solution to the proposed method [1] .

The disadvantage of this method is the significant. Costs and losses of 1 tin.

The aim of the invention is to reduce the cost and increase the extraction of tin.

This goal is achieved by the fact that ²¹ finely dispersed materials are mixed with granulated slag in a ratio of (0.2-1): 1, the mixture is brought to a moisture content of 1-5% and loaded into the oven in portions of 20-60 weight. % (By weight of the melt ² of ferruginous slag). The mixture is moistened with water vapor or a 0.1 - 1% solution of a surfactant, for example sulfite-alcohol stillage, or by mixing the mixture with slurry pulp. thirty

The direct fuming of finely dispersed tin-containing materials (so-called sludge) with a particle size of 0.3-0.07 mm is impeded by a high dispersion of particles in the presence of refractory components: 20-30% of silicon dioxide,

3-20% of calcium oxide. This leads to a relatively slow assimilation of the material in the slag melt, a large dust removal ^{0 of the} material and the loss of tin.

The essence of the method lies in the fact that the mixing of finely dispersed tin-containing materials with granular 5 slag in the ratio (0.2-1): 1 leads to the adhesion of dispersed materials on the surface of granules of recycled slag obtained by spraying a fusible molten glandular slag by a water stream. This 1 reduces the removal of material with gases and the duration of assimilation of the charge in the molten slag, and therefore reduces the loss of tin.

Bringing the moisture content of the mixture to 1-5%> improves the adhesion of the dispersed material to the surface of the slag particles. Released water containers, interacting with dispersed sulfides, provide sulfide ion transfer, prevent the formation of a metal phase and thus intensify sublimation processes.

The use of water vapor, pa or a 0.1-1% solution of a surfactant, such as sulphite-alcohol stillage, promotes more uniform wetting of the charge and increases the adhesion of the dispersed material to the slag.

The charge from the finely divided material and granular slag is loaded onto the molten bath in portions in an amount of 20-60 weight. % (based on the weight of the melt of ferrous slag) and alternate with the loading of crushed slag. This allows the slag in the bath to be kept fusible and fluid, preventing its viscosity from increasing.

To stabilize the operation mode of electrostatic precipitators during charge loading, the supply of air blast is reduced by 20-50%.

The method worked out in an industrial environment.

Example 1. 16 kg of finely divided tin-containing material with a particle size of 0.3-0.07 mm, composition,%: tin 7.3, iron oxide 3, silicon dioxide 31, calcium oxide '3 and 38 kg of granulated slag (ratio 0.4 : 1 composition,%: tin 0.4, iron oxide 20, silicon dioxide 32 and calcium oxide 17) were mixed and the humidity was adjusted to 5% by irrigation with water. The mixture was loaded in two stages into the furnace, where 20 kg of crushed slag was previously melted. The temperature in the furnace was maintained equal to 1200 ° C. Before loading the mixture into the bath, 17 kg of crushed slag of the specified composition was supplied. After loading a portion of the charge, 4 kg of pyrites and 5 kg of coke were introduced into the furnace, the molten bath was blown through the electrode with air for 160 minutes. The slag discharged from the furnace contained 0.1% tin; the tin content in the sublimates is 61%. Extraction of tin to dust 97%.

I

Example 2. Crushed slag in an amount of 3 g of the same composition as in example 1 was melted in a furnace and the melt temperature was maintained at 1200 ° C. The charge was prepared in an amount of 8 tons at a 1: 1 ratio of finely divided tin-containing material,%: tin 8, iron 3, silicon dioxide 30, calcium 3, and 'granular slag of the specified composition. The mixture was moistened with a 3% solution of sulphate-alcohol stillage with a reagent concentration of 0.6%. The mixture was loaded into the furnace in two steps ^δ ma. Before loading the charge into the furnace, 1.2 tons of crushed slag was added, containing (%): tin 6, iron oxide 18, silicon dioxide 36, calcium oxide 19, then 560 kg of coke and 600 ig of sulfur pyrite. After 10 120 minutes of purging the bath with a fuel oil-air mixture, slag was released from the furnace. The tin content in the slag is 0.14%, in sublimates 60%, the extraction of tin in dust is 96.2%. After reducing smelting of dusts, the total extraction of tin from finely dispersed material into the crude metal was 92.4%.

According to the known method, including electric melting, fuming and melting of dusts, the extraction of tin in the crude metal 20 is up to 92% · (

Claims (4)

Claim 1. A method of processing finely divided 25 tin-containing materials by fuming; on a slag bath, including melting them with coke and sulfur pyrite, purging with a mixture of air with a reducing agent, trapping tin dust and 30 smelting reduction, characterized in that, in order to reduce costs and increase the extraction of tin, finely dispersed materials are mixed with granulated slag in the ratio (0.2—35 1): 1, the humidity is adjusted to 1-5% 'and loaded into the oven in portions of 20-60 weight. % (of the weight of the molten glandular slag). 2. The way io π. 1, characterized in that the moisture content of the mixture is adjusted vv-food- 40% 0.1-1% solution of a surfactant. 3. The method according to Π..Π. 1-2, characterized in that the moisture content of the mixture is brought by mixing granulated slag with pulp 45-sing sludge. 4. The method according to π. 1, characterized in that the moisture content of the mixture is adjusted by blowing it with water vapor.