SU1557184A1 - Method of processing zinc-containing materials by waelz process - Google Patents

Abstract

This invention relates to non-ferrous metallurgy, in particular, to methods for producing zinc oxide by baits. The goal is to increase the recovery of non-ferrous metals and reduce the cost of the carbonaceous reducing agent. The method involves the preparation of a mixture of a mixture of zinc-containing materials with coking and a fraction of the spent thermal insulation of graphitization furnaces with a particle size of 2 mm and the restoration roasting of the resulting mixture. 2 tab.

Description

This invention relates to non-ferrous metallurgy, in particular, to methods for processing zinc-containing raw materials by chelating.

The purpose of the invention is to increase metal recovery and reduce the cost of carbonaceous reducing agent.

The known method of processing zinc-containing materials by valving includes a blending with the used heat insulation of graphitization furnaces with a particle size of 2-10 mm and coking and reducing firing of the resulting charge. In the proposed method of processing zinc-containing materials, instead of the suit of coke in the Veltsev mixture in known quantities (1.5-10% of the charge), used heat insulation of graphitization furnaces with a particle size of minus 2 mm, i.e. waste carbon-containing material. This provides, in comparison with the known method, a reduction in the cost of the carbonaceous reducing agent. Another positive effect is achieved due to the ability of silicon carbide contained in the 2 mm fraction to reduce zinc and lead from hard-to-repair compounds (sulphides, silicates, ferrites) while simultaneously bonding iron oxides into hardly-recoverable compounds (silicates) with silica, which is also present in this material: MeS + 2FeO + SiC + C0i5 (1)

MeO-SiQj, + 2FeO + SiC -Me + 2FeO x

x Si02 + CO.; (2)

MeO FejjO ъ + SiC + COZ;

2FeO + Si02-2FeO SiO.

Extraction of zinc and lead from their hardly-repairable compounds provides an increase in the extraction of metals into velco-acids, and the binding of iron oxide to silicate reduces the content of -Me + 2FeO-SiOz + FeS +

Me + 2FeO-Si02 +

(L

with

ate Cn

four

00 4

metallic iron in the clinker, which reduces the extrusion and the formation of metallized crisps in the furnace.

The method is carried out as follows.

The spent heat insulation of graphitization furnaces with a particle size of 2 mm to reduce the removal of its dust-like fractions (-0.5 mm) from the kiln furnace with a stream of waste gases is pre-moistened and mixed with zinc-containing materials. The resulting mixture and coke breeze are loaded into the kiln furnace. Recovery calcination is carried out at 1200-1300 ° C.

The amount of waste heat insulation introduced into the charge of the graphitization furnaces with a particle size of -2 mm is kept within known limits: 1.5-10% of the charge, preferably 5-10%. With the lower limiting content of the spent thermal insulation of 2 mm in the mixture of heat impurities, a significant increase in the extraction of metals into veloxoids and a decrease in the formation of heat in the furnace in comparison with the known method is not achieved. Increasing the content of waste heat more than 10% leads to a decrease in the productivity of the pellet furnace for the processing of the metal-containing charge due to the large amount of injected ash. At the same time, there is practically no increase in zinc extraction in velcoacea, and lead extraction falls due to its reduction to the low volatile metal phase.

Example. Comparison of indicators of the known and proposed methods of processing zinc-containing materials by the Weltz.

Conduct the charge of zinc-containing materials made up of zinc cakes and lead smelting slag in an integrated laboratory pellets of 0, m at 1200 ° C and the duration of each experiment for 24 hours.

The mixture of zinc-containing materials has the following composition,%: zinc 16.0 lead 4.5; iron 19.6; silica 16.8.

The spent heat insulation of graphitization furnaces is dissipated, and the obtained fractions of 2-10 mm and -2 mm are mixed.

, with zinc-containing materials and coc (Sicom,

ten

15

20

25

thirty

35

40

45

50

55

In tab. 1 shows the characteristics of carbonaceous reducing agents.

The amount of waste heat insulation of graphitization furnaces in the mixture of thermal processing of the compared processing methods is 5 and 10%, and coking is based on the previously obtained data on the heat balance of the furnace and the reactive heat engineering characteristics of the carbonaceous reducing agents used. The charge of each experiment is 15 kg.

At the end of the experiment, the furnace is completely unloaded and cooled, the internal cavity of the furnace is inspected for insignificant formation, the resulting wall is removed and weighed.

In tab. 2 shows the performance indicators for the charge of zinc cake and lead smelting slag according to the known and proposed processing methods.

The results of laboratory experiments in the table. 2 show that the proposed method of processing zinc-containing materials by valving with the use of spent thermal insulation of graphitization furnaces with a particle size of 2 mm instead of a fraction of its size of 2-10 mm with an optimum content in the Velzev mixture (5-10% of the charge) provides an increase in zinc recovery from 95.2 to 96.5-97.7% (1.3-2.5%), lead from 93.5 to 94.3-95.1% (0.8-1 , 6%), a decrease in the content of metallic iron in the clinker from 72 to 56.7–61.0% (by 11–15.3%), which ensures a reduction in the mass formed, nastily in the oven for the same time interval. at 36.8-51.2%.

Claims (1)

Invention Formula A method of processing zinc-containing materials by valance, including their blending with spent heat insulation of graphitization and coking furnaces and restoration roasting of the resulting charge, characterized in that, in order to increase the recovery of non-ferrous metals and reduce the cost of carbonaceous reducing agent, the spent heat insulation fraction of the furnaces graphitations with a particle size of minus 2 mm. Table 1 Coxy 6850 74.4 14.2 T 6 l c "2