Method for solidifying and stabilizing fly ash through synergy of ardealite and red mud

A phosphogypsum and fly ash technology, applied in solid waste management, sustainable waste treatment, climate sustainability, etc., can solve the problem of high cost and achieve the effect of reducing leaching rate, reducing curing time and increasing compactness

Active Publication Date: 2021-06-25
CHINA CITY ENVIRONMENT PROTECTION ENGINEERING LIMITED COMPANY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The chemical agent stabilization method has a small expansion volume and better curing effect, but the chemical treatment of fly ash has the disadvantage of high cost

Method used

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  • Method for solidifying and stabilizing fly ash through synergy of ardealite and red mud
  • Method for solidifying and stabilizing fly ash through synergy of ardealite and red mud
  • Method for solidifying and stabilizing fly ash through synergy of ardealite and red mud

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] A method for solidifying and stabilizing fly ash with phosphogypsum in conjunction with red mud, comprising the following steps: adding water accounting for 45% of the mass percent of phosphogypsum to the original phosphogypsum, fully mechanically stirring and mixing the phosphogypsum and water, separating solid and liquid, and extracting phosphorus Soluble impurities in gypsum, collect solids and liquids respectively to obtain washed phosphogypsum and washing solution, dry the purified washed phosphogypsum at 120°C for 1-3 hours, add quicklime accounting for 5% by mass to the dried phosphogypsum Mix and grind to prepare phosphogypsum powder. After drying the original red mud, add quicklime accounting for 2% of the mass of the red mud for mixing and grinding to obtain red mud powder; according to the mass percentage, it is phosphogypsum powder 65%, fly ash 5%, 15% red mud powder, and 15% mineral powder are mixed together, and then the admixture whose mass percentage is 8...

Embodiment 2

[0038] A method for solidifying and stabilizing fly ash with phosphogypsum in conjunction with red mud, comprising the following steps of adding water accounting for 38% by mass of phosphogypsum to the original phosphogypsum, fully mechanically stirring and mixing the phosphogypsum and water, separating solid and liquid, and extracting the phosphogypsum soluble impurities in medium, collect solids and liquids respectively to obtain washed phosphogypsum and water washing solution, dry the purified phosphogypsum at 180°C for 1h to 3h, add 2% quicklime to the dried phosphogypsum and mix, Carry out grinding treatment to prepare phosphogypsum powder, dry the original red mud and add quicklime accounting for 1% of the mass of the red mud for mixing and grinding to obtain red mud powder; according to the mass percentage, the phosphogypsum powder is 25%, and the original fly ash is 10% %, 50% red mud, and 15% mineral powder, and then add the above-mentioned admixture with a mass percen...

Embodiment 3

[0044] A method for solidifying and stabilizing fly ash with phosphogypsum in conjunction with red mud, comprising the following steps of adding water accounting for 35% of the mass percent of phosphogypsum to the original phosphogypsum, fully mechanically stirring and mixing the phosphogypsum and water, separating solid and liquid, and extracting the phosphogypsum soluble impurities in medium, collect solids and liquids respectively to obtain washed phosphogypsum and water washing solution, dry the purified phosphogypsum at 180°C for 1h to 3h, add quicklime accounting for 1% by mass to the dried phosphogypsum and mix, and carry out Grinding process is used to prepare phosphogypsum powder. After drying the undisturbed red mud, adding 0.2% of the mass of the red mud with quicklime for mixing and grinding to obtain the red mud powder. According to the mass percentage, 20% of phosphogypsum powder, 20% of undisturbed fly ash, 25% of red mud powder, and 35% of mineral powder are mix...

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Abstract

The invention relates to the technical field of resource utilization of bulk industrial solid wastes, in particular to a method for solidifying and stabilizing fly ash by synergy of ardealite and red mud, which comprises the following steps: uniformly mixing washing liquid and fly ash to obtain fly ash slurry; mixing and stirring fly ash, mineral powder, an additive ardealite powder and red mud powder to prepare a curing agent; and naturally curing the fly ash slurry for 2-24 hours, and adding a curing agent into the fly ash slurry to further cure and stabilize the heavy metals in the fly ash. According to the method disclosed by the invention, in the fly ash curing process, the alkalinity of the fly ash is neutralized by utilizing purified ardealite water washing liquid, soluble phosphoric acid, hydrogen phosphate radicals, dihydrogen phosphate radicals and fluorine ions react with Pb<2+> to generate stable mineral precipitates such as lead phosphate, lead fluorophosphate and lead chlorophosphate, so that the effect of curing and stabilizing the fly ash is achieved, and the leaching rate of lead in the fly ash is reduced. The curing agent is added into the fly ash slurry, and is excited to react to generate a hydration product to secondarily cure / stabilize heavy metals in the fly ash.

Description

technical field [0001] The invention relates to the technical field of resource utilization of bulk industrial solid waste, in particular to a method for solidifying and stabilizing fly ash with phosphogypsum and red mud. Background technique [0002] Phosphogypsum is an industrial waste residue produced by wet process production of phosphoric acid, the main component is calcium sulfate dihydrate (CaSO 4 2H 2 O) Same as natural gypsum, because it contains impurities such as phosphoric acid and calcium phosphate, it is called phosphogypsum. According to the statistics of Phosphate and Compound Fertilizer Industry Association. [0003] Red mud is an industrial solid waste discharged from the aluminum industry when extracting alumina. On average, 1.0-2.0 tons of red mud is produced for every ton of alumina produced. China is the world's largest producer of alumina. According to statistics from the National Bureau of Statistics, China's cumulative alumina output in 2018 was 7...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B28/14C04B18/08C04B18/04
CPCC04B28/143C04B18/08C04B18/0409C04B2111/00017C04B18/141C04B22/124C04B22/148C04B12/04C04B24/04C04B22/126C04B22/147C04B22/0006C04B22/08C04B22/16C04B22/14Y02W30/91
Inventor 姜明明邵雁郭华军胡国锋陈堃许晓明史记熙
Owner CHINA CITY ENVIRONMENT PROTECTION ENGINEERING LIMITED COMPANY
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