SU1678793A1 - Method for slag treatment - Google Patents

Abstract

The invention relates to methods for the treatment of slags, for example blast furnaces, used in the production of slag-containing living materials in the building materials industry. The aim of the invention is to increase the utilization of the heat of the molten slag. The method of slag treatment involves introducing 1.0–5.0 wt.% Cement dust into the jet of liquid-hot slag melt and melt granulation. Cement dust, before introducing slag into the molten stream, is adjusted with silicon-containing additives to obtain a low-base cement mixture with, 76-0.86. As a silicon-containing additive, waste of gravity coal preparation is used. 1 hp f-ly, 1 ill., 3 tab.

Description

The invention relates to methods for treating slags, e.g. blast furnaces, used in the production of slag-containing living materials in the building materials industry.

The aim of the invention is to increase the utilization of the heat of molten slag.

The drawing shows a granulation plant.

The granulation plant includes a hopper 1 for preparing a homogeneous low-base mixture based on cement dust and corrective silicon-containing additives, a slag carrier 2 with a ladle 3, an inclined drain chute 4, onto which the liquid-liquid blast furnace slag 5 is discharged, the dispenser 6 is a mixture of dust and corrective additives, pneumatic pump 7 for pneumatic transportation of a mixture of dust with corrective additives, pneumatic nozzles 8 and 9 for injecting this mixture into a stream of slag, water nozzle 10 for supplying cooling water, a drum valve a null torus (turntable) 11, which during rotation disperses slag and produces granulate 12, scraper bucket 13 for transporting granulate from the collecting platform to the bunker, drying and grinding unit 14, and storage tank 15 for storing and homogenizing the crushed granulate.

The method is carried out as follows.

In the bunker 1 with a capacity of 60 tons, equipped with systems of pneumatic loading, pneumatic mixing and unloading, load 46.5 tons (92.84%) of dust from electrostatic precipitators of cement production and 3.5 tons (7.03 wt.%) Crushed quartzite used as silicon-containing corrective additive, and mix. Thus, 50 tons of low-base cement mixture, 80, are prepared. The initial chemical composition of dust and quartzite is given in Table 1.

cl

with

o- vj with

-vl o

with

When feeding slag carriage 2 with a fiery liquid slag melt to the granulation unit, I install its bucket 3 opposite to the inclined drainage chute 4. The dosed discharge of the fiery liquid molten slag 5 into the inclined chute is carried out by adjusting the rate of tilt (canting) of the slag carriage. The beginning of the discharge of the molten slag is combined with the beginning of the injection of a mixture of dust into the stream of the molten dust with corrective additives. The dosing of the corrected silicon-containing additives of cement dust introduced into the slag melt is carried out by the dosing unit 6. Moreover, the dosing unit 6 is adjusted so that the consumption of the powdery additives is 5% by weight with respect to the consumption of the liquid slag. In this case, the slag melt discharge rate is 8 t / min, the consumption of low-base cement mixture is 0.4 t / min. By means of a pneumatic pump 7, the lowered basic charge is fed to the nozzles 8 and 9, with which the low basic charge is directly introduced into the slag melt stream. In this part of the mixture by the nozzle 8 is served under a stream of slag (underlying layer - along the bottom of the gutter), and the other part of the mixture by the nozzle 9 is fed over the stream of slag. Formed with a mixture of slag with particles of the mixture by gravity flows to a rotating drum-granulator 11 cooled by a water nozzle 10, with which it is used to disperse (granulate) the mixture of the slag melt and the mixture. The granulate 12 is accumulated at a site with a drainage system that provides filtration and reuse of water used to cool the slag melt and barabane granulator 11. The resulting granulation is 0.5–15.0 mm coarse after dewatering with 13 ш With the help of a winch, it is transported to the hopper of the drying-grinding plant 14. The product of grinding granulate is pneumatically fed into the storage tank-mixing tank 15. The crushed slag thus obtained is then used or as a component cement raw batch or as active mineral additives in the preparation of cement clinker.

In order to determine the advantages of the proposed slag treatment method in comparison with the known method of granulation, a series of comparative experiments are carried out. In these experiments, the efficiency of heat assimilation of a fiery-liquid slag melt when entering into

a melt of a series of electrostatic precipitators of the same dust, but corrected with silicon-containing additives to obtain a low-base charge. Degree of learning

(utilization) of the heat of the fiery liquid melt is estimated by determining the loss on ignition of both the initial dust samples and the crushed samples of the granulate obtained after the cement dust is introduced into the molten slag.

As a silicon-containing additive, in addition to quartzite, in experiments, silica dust was used from ferroalloy production.

Experiments were also carried out to assess the effect of gravitational coal-enrichment wastes in cement dust on the intensification of heat treatment in the molten slag particles

the cement dust and the grindability of the granulate obtained in various experiments.

Table 2 shows the compositions of dust mixtures with corrective additives. The results of the experiments are given in table.3.

Thus, when adjusting cement dust introduced into the slag melt with silicon-containing additives to obtain a low-base cement mixture with

КН 0.76-0.86, an increase in the efficiency of heat recovery of the melt is achieved in comparison with the known slag treatment method, when a row of dust is introduced into the melt - by 16.4 - 20.6%. Thanks to this

a granulate of blast furnace sludge is obtained, which, when used, reduces the fuel consumption for clinker burning when using granulate as a raw material component, and also reduces

energy consumption for joint grinding of clinker and granulate using the latter as an active mineral additive to cement.

Claims (2)

1. A method for treating slag, comprising introducing into the jet of fiery liquid molten slag 1.0-5.0 wt.% Cement dust and melt granulation, characterized by 0 by the fact that, in order to increase the utilization of the heat of the slag melt, cement dust, before introducing the slag melt into the jet, corrects the silicon-containing additives to obtain a low basic cement blend with a CH of 0.76-0.86. 2. The method according to claim 1, in which it is used so that, in order to increase the grindability of the granulate, the waste of gravity coal preparation is used as a silicon-containing additive. Table 1 changes in losses during spilling of dust,%, when melting: common cement dust (, 42) dust, corrected by quartzite to KN 0.88 0.86 0.80 0.76 0.73 dust, corrected waste-ferroalloy production to KN 0.88 0.86 0.80 0.76 0.73 table 2 76.0 80., 89.2 91.5 93.0 90, L 80.3 93.4 95.6 91.3 one dust corrected by waste of gravitational coal preparation to KN 0.86 0.86 0.80 0.76 0.73 granularity, relative units: non carbon inclusive waste including waste coal (8.22Z in the composition of the powder mixture introduced into the melt) eight Continuation of table 3 PIP 80.5 94.1 96.3 98.6 91.5 1.0 1,025 P h ff / j gfbjy js / sstyS /// /// /// ///. tf 8 stock Z, si to On obtig