Multistage precipitation separation system for solid-liquid separation of phosphated residue

Abstract

The invention discloses a multistage precipitation separation system for solid-liquid separation of phosphated residue. The separation system comprises a reaction kettle, a main sedimentation tank, athree-stage secondary sedimentation system, a centrifugal solid-liquid separator, a liquid storage tank, a plurality of connecting pipelines and a plurality of conveying pumps; wherein a main sedimentation tank is arranged on the side edge of the reaction kettle; the water inlet end of the main sedimentation tank is connected with the output end of the reaction kettle through the connecting pipelines; the conveying pumps are arranged on a connecting pipeline between the reaction kettle and the main sedimentation tank; and the three-stage secondary sedimentation system is arranged on the side edge of the main sedimentation tank. According to the invention, the main sedimentation tank and the three-stage secondary sedimentation system are arranged to carry out multiple times of sedimentationand separation on the phosphated residue mixed solution; the phosphated residue solid-liquid separation quality is improved, the possibility that subsequent filtrate still contains solid residues andthe like due to the fact that phosphated residues react with flocculating agents and other drugs too slowly is prevented, the phosphated residue solid-liquid separation efficiency is improved, the content of phosphated residues in liquid obtained after solid-liquid separation is small, environmental pollution is relieved, and the phosphated residue utilization rate is increased.

Description

【Technical field】 [0001] The invention relates to the technical field of phosphating slag treatment, in particular to the technical field of solid-liquid separation of phosphating slag. 【Background technique】 [0002] Phosphating is a commonly used surface treatment technology, which is widely used in industries such as automobiles, chemicals, ships, aerospace and household appliances. During the phosphating process, along with the phosphating film-forming reaction, phosphating slag precipitates will continue to be generated. Phosphating slag belongs to hazardous waste. In the "National List of Hazardous Wastes", phosphating slag is acidic and mainly contains iron, zinc and phosphate radicals; at the same time, it also contains a certain amount of calcium, potassium and nickel according to the type of phosphating solution used. Plasma. If the phosphating slag is directly discharged into the soil, the phosphate and other substances in it will be eroded by weathering, rain a...

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Problems solved by technology

Therefore, if the phosphating slag is not treated and discharged into the environment, it will cause serious pollution to soil and water bodies. However, the existing separation equipment is not completely separated, and the filtrate after solid-liquid separation may still contain solid residues. Phosphating The phosphating slag reacts too slowly with drugs such as flocculants, resulting in the possibility that the subsequent filtrate still contains solid residues. These phosphating slags are discharged directly without treatment and will pollute the environment.

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