Device and method for preparing cement and co-producing sulfuric acid by cooperating high-temperature liquid blast furnace slag with phosphogypsum/desulfurized gypsum

Abstract

The invention discloses a device and a method for preparing cement and co-producing sulfuric acid from high-temperature liquid blast furnace slag and ardealite / desulfurized gypsum, and relates to the field of solid waste resource utilization, and the device comprises a gypsum crushing and drying system and a fluidized pre-decomposition system communicated with the gypsum crushing and drying system; the lower end of the liquid-state fluidization pre-decomposition system is communicated with the slag liquid receiving and sintering system, the top of the liquid-state fluidization pre-decomposition system is connected with the cyclone separation system, the bottom of the slag liquid receiving and sintering system is communicated with the sintered liquid-state cement atomization pulverization and cooling heat exchange boiler system, and the top of the cyclone separation system is communicated with the acid making system. Compared with the prior art, the method has the beneficial effect that high-value and high-efficiency resource utilization of the blast furnace slag, the phosphogypsum or the desulfurized gypsum is realized.

Description

technical field [0001] The invention relates to the field of resource utilization of solid waste, in particular to a device and a method for co-producing sulfuric acid with high-temperature liquid blast furnace slag and phosphogypsum / desulfurized gypsum for cement production. Background technique [0002] my country's steel output accounts for more than 56% of the world's total. Crude steel output exceeded 1 billion tons for the first time, and pig iron nearly 900 million tons. The production of 1 ton of pig iron produces 0.3-0.6 tons of blast furnace slag. When the blast furnace slag is discharged from the blast furnace, the temperature is about 1450°C, and its sensible heat reaches 1621.6KJ / Kg. The blast furnace slag treatment currently adopts the water quenching process, and the heat of the blast furnace slag is basically not recovered; the main chemical components of the blast furnace slag are CaO, SiO 2 、Al 2 o 3 And MgO, which account for more than 95% in blast furn...

AI Technical Summary

Problems solved by technology

[0008] However, the decomposition temperature of phosphogypsum and desulfurized gypsum is high (1100-1200℃), and the decomposition time is long. Liquid phase, and after the liquid phase wraps phosphogypsum and desulfurized gypsum, it will further prevent the decomposition of phosphogypsum and desulfurized gypsum, thus prolonging the decomposition time of phosphogypsum and desulfurized gypsum, causing the preheater and decomposition furnace to stick to the wall and frequently block Therefore, it is difficult to choose the decomposition technology outside the kiln for cement production, and only the dry long kiln production process can be used for production. The size of the kiln is large, the energy consumption is high, the investment is large, the output is low, and the economic benefit is poor.

[0009] The full combustion of fuel in the kiln and the firing of high-quality cement clinker require an oxidizing atmosphere, while the gypsum decomposition of phosphogypsum and desulfurized gypsum requires a reducing atmosphere. Firing and decomposition are contradictory and difficult to reconcile, and production control cannot give consideration to both, resulting in poor quality and unstable strength of cement clinker; Normal operation of the acid section

[0010] Due to many difficult problems in the technology of phosphogypsum decomposition to produce cement and co-production of sulfuric acid, it is difficult to convert phosphogypsum and desulfurized gypsum into cement for mass use

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