SU1141085A1 - Charge for making periclase-spinellide clinker - Google Patents

Abstract

CHARGE FOR MANUFACTURING PERIKLAZOShPINELIdaOGO CLINKER comprising chromite, caustic magnesite, water, and waste in the electric field of fine off-gas cleaning of kilns, characterized in that, with a view to reducing the formation of ferrochromium during melting and povsheni yroizvoditelnosti melting furnace further comprises alumina in the following ratio components, wt.%: Chromite 30-60 Caustic magnesite 5-25 Water6-14 CO Fine-dispersed waste from gas cleaning kilns kiln spent in an electric field5 -25 Alumina 10-20 (X tn

Description

The invention relates to the refractory industry, to the manufacture of periclase spinelide. 1l of anker intended / dl for the production of refractory products used in the lining of vaults and walls of open-hearth and electric steel-smelting furnaces, as well as the use of steel vacuuming. The known charge is inclusive of 20-80% Mgd and 80-20% chromite with a grain size of 0.044 mm, which is burned on clinker prior to sintering at 1975 ° C. Cl. The disadvantages of this batch are high furnace dust and fuel consumption. A charge of 21-25% chromite and 75-79% caustic or calcined magnesite is also known, which is mixed, briquetted and burned on clinker at 2,000-210 ° C. 2. The disadvantages of this mixture are low strength after briquette molding, high dustiness and high fuel consumption required to achieve a high calcination temperature A known charge for obtaining a wedge of kerac, including 20% chromite, 80% caustic magnesite, and water (over 100%), which is briquetted and calcined at a high temperature in a rotary kiln t3J. The disadvantages of this mixture are low durability after the for1 (yuvani on the press rolls, a large number of fine fractions in the clinker (less than 1 mm), high dust from the kiln and fuel consumption. Low strength of the briquette after molding is due to the fact that the caustic magnesite contains a large amount (up to 40%) of non-hydratable grains of raw magnesite and inactive JC hydration of calcined magnesite with a relatively low content of magnesium oxide particles, active to hydration and hydraulic hardening Low briquette strength due to There is no formation of large quantities of small fractions (grains smaller than 2 mm) due to abrasion and destruction of the briquette during transportation, pouring of the briquette and movement in the rotary furnace. If this briquette is smelted in an electric arc furnace to obtain spindle clinker, then The amount of fines is high (up to 30%) of the pulverizer from the furnace and the chemical composition of the melted material is changed, and a large amount of ferrochrome is formed (up to 20%). Closest to the invention is a mixture for clinker, containing chromite, caustic magnesite, water, and fine-dispersed waste from gas purification of kiln furnaces of the following composition, worked out in an electric field, wt.%: Complex sulphates of potassium, sodium, magnesium and calcium 1-20 Carbonates and magnesium and calcium silicates 3-15 Magnesium fluoride O 1 5,0 Periclase Else with the following ratio of components, wt.%: Chromite 12-55 Caustic magnesite 10-40 Water8-25 Waste gas cleaning roaster in an electric field y. 10-40 The mixture is stirred, preformed. The briquette is burned in a rotary kiln or melted in an electric arc kiln on a block or on release, followed by sawing or grinding of directional blocks or billet yutker 4. The disadvantage of the known charge is that when producing a melted clinker from a mixture with a chromite content of more than 20% during melting ferrochrome is formed in large quantities and in the form of large pieces due to the reduction of chromium and iron oxides, which necessitates the subsequent enrichment of clinker with magnetic separation. In addition, equipment wear is observed when crushing and grinding such clinker. When the chromite content is up to 20%, ferrochrome is formed fine-grained and in smaller quantities, but it also adversely affects the properties of the clinker, reducing its refractoriness. A disadvantage of the known charge is also the reduced performance of electric arc furnaces during smelting briquette. The aim of the invention is to reduce the formation of ferrochrome during melting and to increase the productivity of the melting furnace. The goal is achieved by the fact that the charge for the manufacture of perineal spinelide clinker, including chromite, caustic magnesite, water and fine-dispersed waste from the gas cleaning of kilns, additionally input alumina in the electric field, in the following ratio of components, May.%: Chromite 30-60 Caustic Magnesium. Water6-14 Electric-dispersed gonokodispersny waste gas cleaning kilns 5-25 Alumina 10-20 Content in the mixture of alumina in a quantity of 10-20%, favors the binding of chromium oxides and iron in resistant to recovery of the spinel type Mg (FeCrAl). This prevents the formation of ferrochrome. An increase in the cBbmie alumina content in the charge of 20% leads to a significant decrease in the refractoriness of the clinker as a result of the formation of an excessive amount of spinelides; with a lower melting point than periclase. By reducing the amount of alumina to less than 10%, a large amount of ferrochrome is formed during melting, example. Chromite, caustic magnesite, gas cleaning waste and alumina spent in an electric field are fed into a pipe mill for mixing and further grinding, the dry mixture and water are fed to a continuous mixer to prepare the mass, and the ready mass is briquetted onto press rollers. The briquette is melted in an OKB-955N electric arc furnace for 18-22 hours, followed by sawing or grinding blocks and processed clinker blanks. Similarly, fused clinker of their known charge is obtained. The presence of ferrochrome inclusions in the clinker is determined by the petrographic method and its refractoriness is determined. The composition of the charge, the content of ferrochrome in the fused clinker and its refractoriness, the performance of the furnace during the melting of the briquette are given in Table. 1 and 2. As can be seen from the table. 1 and 2, the use of the proposed mixture in comparison with the known reduces the formation of ferrochrome from 1.9-15.0 to 0.01-1.1%, while the productivity of the smelting furnace rises from 303-320 to 382405 kg / h. The recoverable economic effect from the use of the invention is 758 thousand rubles. in year. Table 1

Chromite

Caustic magnesite

Water

Waste gas cleaning waste

Alumina

12

55

60

55

32 21

18 8

5 6

10 7

35

14 15

nineteen

8 20 Refractoriness of clinker after enrichment.

Ferrochrome Magnetic Separation Table

Claims (1)

MIXTURE FOR THE PRODUCTION OF PERICLASOSPINELIDA CLINKER, including chromite, caustic magnesite, water and finely dispersed waste gas purification kilns from the electric field, characterized in that, in order to reduce the formation of ferrochrome during melting and increase the productivity of the melting furnace, it additionally contains , wt.%: Lame Caustic magnesite Water Fine-dispersed finely dispersed waste gas purification kilns Alumina 30-60 5- 25 6-14 5-25 10-20 SIL ·, 1141085