Pipeline and dwell tank desiliconization method of fly ash

Abstract

The invention relates to a pipeline and dwell tank desiliconization method of fly ash, which comprises the technical process that the fly ash is added into an NaOH solution to be prepared into fly ash material pulp; the materials are sent into a secondary multi-inner-pipe sleeve pipe preheater to be preheated to 70 to 75 DEG C; the preheated fly ash material pulp enters a multi-inner-pipe heater to be heated to 130 to 135 DEG C; then, material pulp enters a heat insulation dwell tank for dwelling 1 to 2 hours in the heat insulation dwelling tank; desiliconized material pulp enters a secondary flash evaporator; the material pulp gradually carries out temperature reduction and pressure reduction according to the grades; then, the material pulp enters a buffer groove; the material pulp is sent into a conventional fly ash separation and washing work procedure through a buffer pump; the material pulp in the buffer tank enters a water cooling type steam lack recovering device in a steam lack mode; and the heat is absorbed by low-temperature circulation water. The method of the invention has the characteristics of high heat utilization rate, low energy consumption, low investment, low operation cost, simple process flow, convenient production operation, convenient cleaning and maintenance and the like, can improve the aluminum-silicon ratio of the fly ash material pulp, and can remove 30 to 35 percent of silicon dioxide in the fly ash.

Description

technical field [0001] The invention relates to the technical field of environmental protection and alumina materials, in particular to the technology of comprehensively utilizing fly ash to prepare alumina. Background technique [0002] Inner Mongolia, Shanxi, Ningxia and Shaanxi are rich in coal resources, with reserves of about 150 billion tons. The alumina content in coal is 9-13%. Calculated only at 9%, the amount of alumina is as high as 13.5 billion tons, far more than the 1.8 billion tons of alumina in my country's bauxite resources. [0003] The coal resources in Inner Mongolia are 13.8 billion tons, and the fly ash produced after industrial production is about 3.9 billion tons, of which the alumina content is 40-51%, which is a valuable resource for alumina production. At present, fly ash is mainly stockpiled, and a small amount is used to make bricks, pave roads, and make cement. Stockpiling not only wastes land, but also pollutes the environment, which is even...

AI Technical Summary

Problems solved by technology

[0009] Aiming at the current problem that the aluminum-silicon ratio of fly ash slurry is low in the process of extracting alumina from fly ash, the present invention provides a method for desiliconizing fly ash by adding a pipeline and a residence tank to increase the aluminum content of the fly ash slurry. Silicon ratio, the purpose of reducing the amount of slag

Images