Method for processing ardealite by using fluidized bed furnace to prepare special anhydrite cementing material

Abstract

A method for processing ardealite by using a fluidized bed furnace to prepare a special anhydrite cementing material comprises the following steps that (1) materials are prepared, namely caked ardealite and massive stone coal or waste rock ballast is crushed; (2) burdening is performed, namely 50 to 80 parts of ardealite, 8 to 25 parts of stone coal and 10 to 40 parts of waste rock ballast are burdened and metered by weight; (3) matured slag is prepared, namely the materials are continuously fed into the fluidized bed furnace and calcined in the oxidative atmosphere at the temperature of 850 to 1280 DEG C for 0.3 to 1.5 hours, the materials overflowing from a discharging port are rapidly quenched to be made into the matured slag; (4) the special anhydrite cementing material is prepared, namely the matured slag is grinded into 80-micron powder containing smaller than or equal to 20% of screen residue mass, and the special anhydrite cementing material is obtained. The special anhydrite cementing material prepared by means of the method contains multiple hydrated active minerals, can be widely used in the cement industry, is high in strength in use and can serve as active residue powder or be used for production of construction materials. By means of the method, investment is small, no wastewater and waste residue is produced, and economical efficiency is high.

Description

technical field [0001] The invention relates to a method for preparing anhydrite gelling material from phosphogypsum, in particular to a method for preparing anhydrite gelling material by treating phosphogypsum with a boiling furnace. Background technique [0002] Phosphogypsum is the waste residue discharged from phosphoric acid or phosphate fertilizer in the phosphating chemical industry. The main component is gypsum-based sulfate, with a content of 78-96%, followed by quartz SiO containing 4-22%. 2 , Soluble phosphate and fluorophosphate and insoluble phosphate, fluorophosphate and aluminosilicate minerals, and contain a small amount of harmful heavy metal elements such as cobalt, strontium, lead, cadmium, etc. [0003] The newly discharged phosphogypsum is a granular material, and it is easy to raise dust when it is disposed of and stored. However, under the action of an appropriate amount of water, the gypsum can be slowly recrystallized and bonded into a hard block. A...

AI Technical Summary

Problems solved by technology

A large amount of discarded phosphogypsum has objectively caused serious pollution and damage to the environment, groundwater and soil

[0004] At present, the research and application of phosphogypsum are mainly focused on four aspects. One is to modify phosphogypsum with lime, that is, add lime to neutralize the soluble phosphate and fluorophosphate in it, and replace natural gypsum for cement production. However, the application effect is not ideal objectively, and the actual consumption is very limited; the second is to convert phosphogypsum into hemihydrate gypsum or a compound of hemihydrate gypsum and soluble anhydrite, that is, 250-500 ℃ Low-temperature heat treatment of building gypsum powder, used to produce gypsum powder, gypsum board, gypsum block and other products, but because the grade and color of phosphogypsum are far inferior to natural gypsum, and contain a certain amount of harmful elements and harmful impurities, and building gypsum products are water-resistant Poor, its actual application consumption is still limited; third, phosphogypsum and lime, cinder, fly ash are mixed and pressed to make bricks after curing, but due to the influence of harmful impurities and harmful elements and the autoclaved curing process can be compared It is good to ensure the volume stability of brick products, but its popularization and application is not ideal; fourth, it is the by-product cement of sulfuric acid production, which leads to popularization and application due to large investment, low sulfuric acid grade, poor economy, and large secondary pollution. obstructed