SU1731850A1 - Charge for fuming process - Google Patents

Abstract

Usage: pyrometallurgical processing of zinc-containing oxidized materials. Essence: the mixture contains low-melting zinc-containing slag, solid carbonaceous reducing agent and, as calcium-containing material, tailings from wastewater treatment in the following ratio of components, wt.%: Low-melting zinc-containing slag 32-46; tailings from wastewater treatment 24-40; restorer rest. 2 tabl,

Description

The invention relates to the metallurgy of non-ferrous metals and can be used in the pyrometallurgical processing of zinc-containing oxidized materials.

The known blend compositions for welders of zinc-containing slags include lime and limestone additives and have the following composition,%: 1. slag 58, lime 13, solid carbonaceous reducing agent 29; 2 slag 26, limestone to 31, solid carbonaceous reducing agent 43.

The indicated compositions of the charge do not allow to obtain clinker, which possesses tough properties, and to use it as a building material. At the same time, the productivity of zinc decreases due to the large amount of processed lime (lime).

The closest in technical essence to the present invention is a mixture containing the following components, wt.%: Low-melting zinc-containing slag 45-68; highly basic zinc containing ore 525; solid carbon reductant rest.

However, as a result of valching of the mixture of such composition, clinker is obtained, which is a mixture of iron oxides, calcium, silicon, and unreacted coke.

Clinker having such a phase composition does not possess tough properties. The dicalcium silicate (Beli g) and tricalcium silicate (alit) give the chewing properties, which are formed by direct contact of calcium carbonate and ore (slag) silica, only at 1400-1500 ° C, and the temperature at which Velcier proceeds (1150 1250 ° C), is insufficient to obtain these silicates.

Therefore, the clinker obtained by the known method cannot be used as a cement additive in the construction industry and, due to its environmental hazards, it requires the construction of landfills for burial.

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The purpose of the invention is to reduce costs and protect the environment.

The goal is achieved by the fact that the known mixture, including low-melting zinc-containing slag, carbonaceous reducing agent and calcium-containing material, as the latter contains tailings from wastewater treatment in the following ratio of components, wt.%:

Fusible zinc-containing slag32-46

Tailings from wastewater treatment

water 28-40

Solid carbon

restoring

Tailings from wastewater treatment, such as zinc production, are a waste product that, due to its environmental hazards, requires disposal.

Characterization of tailings is as follows: composition, wt.%: Zinc 5-20; cadmium 0.2-0.5; calcium 15-30 (including in the form of fluoride 0.5-1.2, the rest in the form of carbonate); iron 2-10; aluminum oxide 2-5; fraction content (-0.074 mm) 100%; reserves - about 90 thousand tons, the annual increase in reserves of 5-10 thousand tons,

The presence in the charge veltsevani tails from wastewater treatment leads to the following.

As the charge moves along the length of the tube furnace from the charging end towards the discharge side in the temperature zone of 720– 750 ° C, calcium fluoride and calcium carbonate contained in the tails interact with each other.

7САСОз CaF;

7САСОз + СаР2 -

7САСОЗ CaF2 - Ly7CaOCaF2 + 7C02.

When the material moves into the zone of temperatures of 890-950 ° C, 7CaO-CaF2 reacts with new portions of calcium carbonate of the charge tails with the formation of 4CaCO7CaO-CaF2. At 975 ° C, the neoplasm is melted.

The fusible slag contained in the charge, depending on the composition, melts in the temperature range of 1000-1100 ° C.

Contact in the furnace of molten silica containing (more than 20%) slag with

molten tailings component (ensures the reaction proceeds: 4CaCOZ 7CaO-CzP2 + 45 452 slag S 11 CaOv CaF2-4Si02 + 4C02. In the temperature zone 1050-1100 ° C the resulting compound decomposes

on alit (tricalcium silicate) and whitens (/ - dicalcium silicate) by the reaction 11CaO CaFr4Si02-3 (3CaOSi02) + 2CaOx xSi02 + CaF2.

Alit and Belit - the main components

cement, giving it a cindering properties. Their share in cement is 50-90%. The resulting clinker is close in composition to cement (the sum of the elite and Belite is 45-50%) and possesses astringent properties.

The composition of the proposed mixture is determined experimentally and is due to the production of clinker that has tough properties suitable for use in construction works, for example,

for the production of cinder blocks, bookmarks for mining enterprises.

When using blends containing less than 28% of tails, free calcium oxide remains in the clinker, which

leads to a partial loss in his living properties,

When using charges containing more than 40% of tails, the resulting clinker has lower adhesion properties,

prone to self-killing. In addition, no protective coating is formed on the furnace lining to prevent the lining from breaking.

Example. Conduct a high speed charge

known and proposed formulations for Velcpec, 41 m long and 2.6 m in diameter (Table 1).

The composition of the initial components of the charge the following, wt.%:

Zinc

Lead Iron Calcium Oxide Fluoride Oxide

Aluminum-calcium silicon

Fusible slag

11.8

2.1

Cleaning tails

wastewater 15,90,12,325,291

Zinkova PUDYA, L0,214,811,82,9

12.4

1.5

0.05

22.3

321.4

N / OB5.1

The composition of the charge for rolling is given in table. one.

In the clinker formation zone, the temperature is 100-115 ° C. Pyrometallurgical processing of charge 1-6 is carried out, in which the tailings content varies from 25 to 42%, including calcium fluoride from 0.03 to 1.46%.

The clinker obtained as a result of pyrometallurgical processing of the charge is subjected to tests for determination of the burning properties.

The clinker was ground to a particle size of 0.08 mm (the residue on the 008 sieve was not more than 15%), then, to determine the compressive strength, beams 40x40x160 mm in size were made of a clinker with sand composition 1: 3 by weight (hardening mixture) and water (40% from the mass of clinker). The beams are kept in the form of under water for 1 day. Then they were disbanded and kept in water for 27 days. After 28 days from the time of manufacture, they were tested in compression using a hydraulic press.

The effect of wastewater treatment tailings on the process of processing low-melting slags is given in Table. 2

As can be seen from the table. 2, when working on charge 5, the quality of the clinker decreases as a substance (the strength drops from 242-307 to 235 kg / cm2), and the proportion of solid reduction of the gel increases from 26-28 to 30% (Table 1).

Pyrometallurgical processing using charge 1 is characterized by a decrease in the strength of clinker as well as from 242-307 to 184 kg / cm, and moreover, at the specified charge, more zinc loss from the clinker.

A comparison of the proposed composition of the charge with the known (see Table 2) shows that with the pyrometallurgical processing of the known charge, clinker is obtained, which does not have tangible properties, when tested, the sample of clinker does not harden, but crumbles. In addition, zinc loss with clinker is higher than 0.6% versus (0.3-0.4)%.

The use of the proposed composition of the charge for baling as compared to the known one provides the following advantages: a commercial clinker is obtained that has toughness properties (compressive strength of the sample is 242-307 kg / cm2), which allows it to be used as a cement additive in construction work and as a bookmark for filling the mine workings, which eliminates the cost of burial, zinc loss from the clinker is reduced from 0.6 to 0.3-0.4%, and extraction into sublimates rises from 92.5 to 96-97%.

Claims (1)

Claiming mixture for felting, containing low-melting zinc-containing slag, solid carbonaceous reducing agent and calcium-containing material, characterized in that, in order to reduce costs and protect the environment, the charge as a calcium-containing material contains tailings from wastewater treatment in the following ratio of components , wt.%: Fusible zinc-containing slag32-46 Wastewater treatment tailings28-40 Solid carbonaceous reducing agent Rest Table 1 Table 2