System and method for treating desulfurization wastewater by lime milk method

Abstract

The invention discloses a system and a method for treating desulfurization wastewater by a lime milk method, and the system comprises a neutralization pretreatment device, a water distribution pulpingdevice, a magnesium hydroxide reaction device, a magnesium hydroxide washing and drying device and a calcium chloride drying device, the neutralization pretreatment device comprises a desulfurizationwastewater raw water tank, a plate-and-frame filter press and a raw water buffer tank; wherein the water distribution pulping device comprises an acidification water tank, an ash milk preparation tank and an ash milk feeding tank, the magnesium hydroxide reaction device comprises a magnesium hydroxide reactor and a magnesium hydroxide overflow liquid tank, the magnesium hydroxide washing and drying device comprises a magnesium hydroxide filter press, a magnesium hydroxide washing tank, a drying box and a calcium chloride solution tank, and the calcium chloride drying device comprises an evaporation crystallizer. The magnesium and calcium in the desulfurization wastewater are separated and recycled, magnesium ions form magnesium hydroxide solids, calcium ions form calcium chloride solids,waste recycling is achieved while the problem of environmental pollution of the desulfurization wastewater of the coal-fired power plant is solved, used reagents are few and cheap, the technological process is short, operation is easy, and the cost is low.

Description

technical field [0001] The invention relates to the field of waste water treatment, in particular to a system and a method for treating desulfurization waste water with a milk of lime method. Background technique [0002] The wide application of limestone wet desulfurization technology in coal-fired power plants has led to an increasing amount of wet desulfurization by-products - desulfurization wastewater. Excessive concentration endangers the stable operation of the system. At present, research at home and abroad is mainly focused on the treatment technology of desulfurization wastewater, but due to the consideration of factors such as cost and market, the attention of desulfurization wastewater recycling technology has gradually weakened. However, a large amount of elements in desulfurization wastewater is a potential resource. Removing and separating chlorine, magnesium, calcium and other ions can realize "zero discharge" of desulfurization wastewater, and at the same t...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a system and method for treating desulfurization wastewater by lime milk method, and to solve the technical problems of complicated procedures and high cost in the prior art

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