Method for preparing soil base fertilizer by using water-quenched slag and fly ash treatment wastewater

Abstract

The invention relates to a method for preparing a soil base fertilizer by using water-quenched slag and fly ash treatment wastewater. The method comprises the following steps of: pretreating water-quenched slag and fly ash, preparing artificial zeolite, namely 4A zeolite, by using an alkali fusion hydrothermal mixing method, firstly purifying calcium-containing wastewater generated in a process of extracting aluminum oxide from fly ash by using a one-step acid dissolution method by using the synthesized zeolite, then continuing to purify nitrogen and phosphorus wastewater, and filtering, drying and grinding the product after wastewater treatment into powder which is directly used as the acid soil base fertilizer. According to the method, the treatment cost is low, secondary pollution cannot be generated in the treatment process, rich calcium ion components in the wastewater are effectively utilized, waste of resources is indirectly avoided, high-value utilization of two major solid wastes in cities is achieved, the potential utilization value of 'mine in cities' is fully improved, two types of industrial wastewater are purified, energy conservation and emission reduction are really achieved, waste is turned into wealth, and the method has ultrahigh practical significance and application value.

Description

technical field [0001] The invention relates to a method for preparing soil base fertilizer by using water-quenched slag and fly ash to treat wastewater, and belongs to the technical field of wastewater treatment. Background technique [0002] Fly ash refers to the fine ash collected from the flue gas after coal combustion, and is the main solid waste discharged from coal-fired power plants. If a large amount of fly ash is not treated, it will generate dust and pollute the atmosphere; if it is discharged into the water system, it will cause river silting, and the toxic chemicals in it will also cause harm to human body and organisms. Water quenching slag is also called blast furnace slag It is the waste slag formed by blast furnace slag treated by water quenching and quenching in the ironmaking process of iron and steel enterprises. At present, there are also patent applications for the treatment of these two solid wastes. For example, Chinese patent CN102391021A discloses ...

AI Technical Summary

Problems solved by technology

Although nitrogen and phosphorus in water can be treated simultaneously, the existing problem is that the composition of the purifying agent is too complex, it is difficult to mix, and the regeneration of the purifying agent is difficult, so that if the product after purifying wastewater is not properly treated, it will easily cause secondary pollution

[0004] Chinese patent CN102380343A discloses a modified artificial zeolite for synchronous denitrification and dephosphorization of slightly polluted water and its preparation method. The fly ash zeolite is modified with rare earth elements to achieve the purpose of synchronous denitrification and dephosphorization, but the problem is that only It has obvious effects on low-concentration nitrogen and phosphorus wastewater, and does not mention the treatment of waste water products, and does not mention the way to regenerate and reuse zeolite. A slight carelessness in modifying zeolite with rare earth elements will cause secondary effects of rare earth elements on the environment. secondary pollution

The disadvantages are: the material production cycle is long, the material regeneration time after wastewater treatment is long, it is difficult to treat the acid wastewater generated by the recycled materials, and the treatment effect after material regeneration drops sharply, making it difficult for the treated wastewater to meet the normal discharge standard

[0006] The current common problems are: for the utilization of fly ash and water-quenched slag, the high-value utilization rate is very low, and there are few ways for high-value utilization; Currently, neutralization treatment with alkali is used, the treatment cost is high, "secondary pollution" will be generated during the treatment process, and zero discharge in environmental protection cannot be achieved. The most important thing is that the main substances in the waste liquid are not recycled, resulting in resources waste

For the treatment of nitrogen and phosphorus wastewater, nitrogen and phosphorus are generally treated separately. There are also the following obvious disadvantages in the treatment process: high cost, easy to generate a large amount of sludge, improper treatment will cause secondary pollution, complex equipment required, etc.

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