SU1504277A1 - Method of processing sulfoarsenic acid solutions containing nonferrous metals - Google Patents

Abstract

This invention relates to the steel industry. The purpose of the invention is to increase the concentration of components in the separated parts. The method of processing steelmaking slag includes the introduction of sand in the amount of 2.5-5.3% into slag melt, 0.5-1.5% of dross, slow cooling with slag separation into two parts: the top - enriched with phosphorus oxides, the bottom - enriched with oxides gland. After separation of the upper crystallized phosphorus-rich oxide part into the remaining liquid part, scale is introduced in the amount of 1.5-2.5% and lime in the amount of 8-12%, the resulting melt is again slowly cooled and divided into two parts. The invention makes it possible to significantly increase the concentration of phosphorus oxides in the upper parts of the slag. Such slag can be used as high-quality phosphate fertilizer in agriculture, and iron-containing parts of slag - in blast-furnace production. 1 tab.

Description

The invention relates to ferrous metallurgy and can be used in the processing of steel slag.

The purpose of the invention is to increase the concentration of components in the separated parts.

The essence of the invention is as follows.

During the crystallization of phosphate slags, lighter crystals of silicophosphates are released from the melt, which float to the top.

enrich them with phosphorus oxides. The degree of enrichment of the upper parts with Phosphorus oxides is opposed to the concentration of PjO in the primary crystals, which in turn depends on the initial composition of the slag. Silicophosphates with a content of 16–18% are released from the melt, which does not allow to obtain in the upper parts more than 18% 5. To increase the concentration of PjOg in the upper parts of the melt, they modify it with sand and sand

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LINE, thereby converting the slag composition to the area of excretion of silicophosphates with a content of more than 22%.

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However, after the separation of the upper parts enriched with phosphorus oxides, the remaining part contains less iron oxides than when implementing the known method. In order to separate the iron oxide-rich concentrate, the remaining liquid part is again modified by additives of lime and scale, transferring the slag to the compositional range, during which crystallization, the maximum possible amount of iron oxide remains in the iron-containing part.

Studies have shown that, during the initial modification, the introduction of sand in an amount of less than 2.52 wt.% Does not ensure the transfer of the galaxy to the area of rich silicophosphate. When slag crystallizes with the addition of more than 5.3% by weight of sand, a eutectic fluid, most depleted in iron oxides, is released from the melt. Modifying the scale in an amount of less than 0.5 wt.% Does not reduce the melt viscosity. Scale additives of more than 1.5% by weight lead to higher processing costs, and no further noticeable reduction in viscosity is observed.

Experiments have shown that with automatic modification of lime input less than 8 and more than 12 wt.1, the slag composition is removed beyond the optimal zone, in which the largest amount of oxides: iron is released in the lower part of the melt.

The introduction of lime leads to an increase in the viscosity of the slag; therefore, scale is again injected into the melt. Entering less than 1.3 wt.% Dross does not provide the necessary viscosity. With the addition of scale more than 1.5 wt.%, The viscosity decreases and the upwelling is quite intensive. Adding scale more than 2.5 wt.%, No further decrease in melt viscosity is observed. In addition, an increase in the scale content of more than 2.5 wt.% Leads to heat losses, as well as to an increase in the cost of the processing process.

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Example. 150 kg of steelmaking slag composition, wt.%: FeO 22.00; CaO A6; Si., 56; MpO 5.41, 11.53, melted in a 150-kVg two-electrode electrothermal furnace with a capacity of 150 kg. After reaching a temperature of 1560 G, the slag was poured into a steel mold expanded to the top, the lower part of which was insulated with an asbestos sheet on the outside. As the mold was filled, sand in the amount of 5.72 kg (3.9%) and scale (1.5 kg) (1.0%) were added to the jet. In all cases, the additives were pre-crushed and thoroughly mixed.

After reaching a temperature of 1500 ° C to a depth of 200 mm, two metal rods were introduced into the melt in the mold. After the upper part was completely crystallized, it was removed from the mold with the help of metal rods frozen in the upper part of the slab. In the remaining mold, the liquid part of the slag was injected with additives of lime in the amount of 15 kg (10%) and 3 kg (2.0%) of scale, after which the melt was cooled, followed by its further separation into two layers enriched in silicates and iron oxides. Samples for chemical analysis were taken from the separated Vlac layers.

The table shows the results of experiments conducted in accordance with the proposed and known methods.

The proposed method allows to increase the content of phosphorus oxides in the upper parts of the slag to a content of 20-22 wt.%, Which makes it possible to obtain highly conventional agricultural phosphate fertilizer from the slag, as well as to use iron-containing parts of the slag in the blast furnace production.

Claims (1)

Invention Formula A method of processing slag slag, which includes pouring lime into the tank, adding lime and scale additives to the melt, cooling with oxygen, blowing it into oxygen, dividing it into two parts, the upper one being solid, enriched with phosphorus, and the lower one being enriched with iron oxides, characterized in that in order to increase the concentration of the components in the separated parts, to the melt the precursor 5150A277 6 However, amounts of 2.5% of 8–12% and 1.5–2.5% respectively were introduced in quantities of 2.5, 1.5% to 0.5% of the mass of the melt, and juice and scale, and lime and scale are cooled and then separated. Well, two parts are introduced into the lower liquid part. Plain basicity, CaO / SiOj + PI O 5 Primary modification, wt.% sand scale lime The content of oxides in the upper layer after the initial modification, May, Feo Pi 5 Secondary modification wt.% lime 1.58 1.58 1.58 1,581,581,58 1.50 2.50 3.91 5,306,51Not administered 0.10 0.50 1.09 1,502,524.28 Did not sit down14,8 5.62 3.96 2.91 2.85 6.1 3.1 14.91 19.56 20.29 21.52 16.02 16.3 7.25 8.00 9.56 12.00 lj; 55 Secondary modification not performed scale The content of oxides in the lower layers of the plaque after the secondary modification, May.%: Feo 1.25 1.50 1.95 2.50 3.51 31.09 39.30 40.92 40.26 30.92 39.2 1.10 0.81 0.53 0.76 1.54 1.3 Secondary modification not performed