SU1428729A1 - Method of ash gravel - Google Patents

Abstract

The invention relates to the production of building materials and can be used in the preparation of porous aggregates from industrial waste heat. To reduce energy consumption, the waste is melted at 1200-1350 ° C, cooled at a rate of 500-800 ° C / min, and the firing of the granules is carried out in vacuum at a vacuum of (1-5) -10 Pa. The aggregate is characterized by a gross density of 100-300 kg / m. 2 tab.

Description

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The invention relates to the production of building materials and can be used in the preparation of porous aggregates and industrial wastes of thermal energy that are melted.

The purpose of the invention is to reduce energy consumption.

The method for obtaining ash gravel, mainly from ash and slag waste from burning brown coal, includes smelting waste, cooling, grinding, pelletizing and burning, thus forming the waste during the burning process of coal, melts at 1200–1350 sec. min, and the pellets were calcined under vacuum at a vacuum of (1-5) 10 Pa. Ashes and slags from burning brown coal are characterized by the following chemical composition,%: SiO 40-55; , 4-10; , 6-14; CaO 5 20-25; MgO 3-6; SO, 0.9-5; 0.3- 1.5, 0.2-0.5, the rest rf.n.n.

Example. Fly ash or furnace slag from the combustion of brown coal, having a temperature after combustion

0 coal 400-800 ° C, is melted at 1200-1350 ° C to obtain a melt, which is intensively cooled in liquid nitrogen () at a speed of 500-800 s / min. After

5 grinding, granulating and firing at a temperature of 850-900 ° C in a low-vacuum furnace with a vacuum of (1-5) -10 Pa, get ash gravel. Characteristics of raw materials

0 and the resulting placeholder are given in table. 1 and 2.

Table 1

The melting point of the raw material, C

Melt cooling rate to ambient temperature, C / min

Melt Cooling Medium:

liquid nitrogen - 196 С

ABOUT

air, -100 C

water (+ yes; - no)

Vacuum discharge during pellet firing, K-10 Pa

Roasting temperature, with characteristic of aggregates:

bulk density, kg / m

1200 1275 1350 1450-2000

800 650 500 300-400

5.0 2.25 1.0

900 875 850 1050-P50

100 200 300 100-300

The proposed method, while maintaining the quality indicators of the aggregate obtained in terms of natural density, reduces energy consumption by lowering the firing temperature to 850-900 ° C and using heat from ash and slag during coal combustion before melting into the melt. A decrease in roasting temperature by an average of 100–200 ° C is associated with the increased activity of microparticles of amorphous ash, which also determines the formation of a durable porous material during roasting ;.

The use of vacuum in the process of burning pellets provides

table 2

preservation of bulk density of filament: filament due to an increase in the volume of micropores during the expansion of facets.

40,

Claims (1)

Formula and invented The method of obtaining ash gravel, mainly from ash and slag waste 45 dts from lignite incineration, including waste smelting, cooling, grinding, granulating and roasting, distinguished by what in order to reduce energy consumption, the 50 strokes are melted at 1200-1ЗЗЗ C, cooled at the rate of SOO-eOO C / MHii, and the firing of the granules is carried out in vacuum at a vacuum of (1-5) 10 Pa.