RU2284361C1 - Charge for waelz process of zinc-containing materials - Google Patents

Abstract

FIELD: non-ferrous metallurgy; processing of zinc sludge and other zinc-containing materials by Waelz process.

SUBSTANCE: charge for Waelz process of zinc-containing materials includes zinc-containing material, coke breeze, anthracite and additionally limestone at the following ratio of ingredients, mass-%: coke breeze, 8-14; anthracite, 14-18; limestone, 1-3; the remainder being zinc-containing material.

EFFECT: reduced consumption of coke breeze at retained and improved parameters of Waelz process.

1 tbl, 1 ex

Description

The invention relates to the metallurgy of non-ferrous metals and can be used for the processing of zinc-containing materials, for example, by-products of zinc electrolyte production - zinc-containing cakes by Weltzing.

A well-known mixture for Wielding, which includes a reducing agent fuel containing an anthracite molybdenum, a reverse reducing agent — a carbon-rich clinker, coke breeze and waste heat insulation of graphitization furnaces in the following ratio of components, wt.%: Anthracite mnite - 8-10; carbon-rich clinker - 10-14; waste heat insulation of graphitization furnaces - 16-20; coke breeze - the rest (USSR AS No. 1767000, class C 22 V 19/38, 1990).

A disadvantage of the known mixture is the high ash content of the fuel-reduction mixture, which reduces the productivity of the Waelz kilns for zinc-containing material.

Known mixture used for the processing of zinc-containing materials by Waelz, containing coke breeze, insulation of graphitization furnaces, zinc-containing material and zinc drosses of electrolyte production in the following ratio of ingredients, wt.%: Coke - 10-15.1; spent thermal insulation of graphitization furnaces - 11.1-15.0; zinc drosses of electrolyte production - 2.0-3.2; zinc-containing material - the rest (USSR AS No. 1678877, class C 22 V 19/38, 1989).

The disadvantages of this mixture is the low productivity of the Waelz kiln, the increased zinc content in the clinker.

Closest to the proposed technical essence and the achieved result (selected as a prototype) is a mixture for Waelz, including coke breeze, anthracite and zinc cake with a ratio of components, wt.%: Coke breeze - 12-17; anthracite - 12-17; zinc cake - the rest (RF patent No. 2060287, class 6 C 22 B 19/38, 1993).

The disadvantage of this mixture is the high zinc content in the clinker.

The technical result of the present invention is to reduce the zinc content in clinker and to reduce plating.

The specified result is achieved by the fact that the Weltz mixture comprises zinc-containing material, coke breeze, anthracite and limestone in the following weight ratio of components:

- Coke trifle - 8-14;

- Anthracite - 14-18;

- Limestone - 1-3;

- Zinc-containing material - the rest.

Tests of the mixture under industrial conditions showed that the addition of limestone to the mixture in the range of 1 to 3% increases the reactivity of solid fuels, in addition, prevents the formation of liquid slag, which stabilizes the mixing process of the mixture and prevents stratification. With a dosage of limestone below 1%, the zinc content in the clinker rises, and with a dosage above 3%, the likelihood of nastyle formation in the furnace increases. Only with this ratio of ingredients can we obtain the maximum reduction in zinc content in clinker and reduce the likelihood of overburden formation in furnaces.

An example of the use of the charge.

As components of the mixture used zinc cake composition, wt.%: Zinc - 20.5%; iron - 19.8; lead - 1.5; copper - 3.5; cadmium - 0.2; coke breeze with a particle size of 0-15 mm composition: ash - 17%, volatile - 2.5%; anthracite with a grain size of 0-20 mm composition: ash - 16%, volatile - 3-3.5%; limestone with a CaO content of 50%. Coke, anthracite, limestone are burdened with a clamshell method, mixed and loaded into a hopper. Material from bunkers with cake and fuel-reduction mixture is simultaneously supplied in a predetermined ratio through conveyors to the loading window of the Waelz kiln (length - 40 m, diameter - 2.5 m). The table shows the options for the compositions of the proposed mixture and for comparison, the composition of the charge of the prototype.

Table 1. Technological indicators of the Weltz mixture of different composition. Test charge The content of components, wt.% The Zn content in clinker,% Nasolation coke anthracite limestone zinc cake Proposed 12 fifteen 2 71 0.62 Not fixed According to the prototype fourteen fifteen - 71 0.87 Frequent overburden

As can be seen from the table, when using the proposed mixture for Waelz, the zinc content in the clinker decreases from 0.87 to 0.62%. Nastyleogenesis during Weltzing according to the proposed method is not fixed.

Claims (1)

The mixture for the Weltzinz of zinc-containing materials, containing coke breeze, zinc-containing material and anthracite, characterized in that it additionally contains limestone in the following ratio of ingredients, wt.%: Coke trifle 8-14 Anthracite 14-18 Limestone 1-3 Zinc-containing material Else