A settling tank for continuous separation of solid content of wet-process phosphoric acid

Abstract

The invention discloses a settling tank for continuous separation of wet phosphoric acid solid content, and belongs to the technical field of phosphoric acid production equipment. The settling tank includes a settling tank body and an upper cover; the settling tank body is provided with a mud scraper which can continuously operate; the settling tank body is externally provided with an acid discharge ring pipe; the acid discharge ring pipe communicates with the settling tank body through a plurality of overflow pipes; the acid discharge ring pipe communicates with a lower acid pipe pump through an acid discharge pipe; the lower acid pipe pump sends an acid to a finished product workshop; the bottom of the settling tank body is provided with a conical slag discharge port; the outlet end of the conical slag discharge port is provided with a slag discharge pipe and a plurality of cleaning valves; the slag discharge pipe communicates with a slag discharge pump. The settling tank can separate the solid content in dilute phosphoric acid, and also can separate the solid content in concentrated phosphoric acid; through structures of an acid feeding guide cylinder, the acid discharge ring pipe, the acid discharge pipe and the valves, continuous acid feeding, continuous precipitation of phosphoric acid and acid layer-by-layer continuous discharge are achieved, qualified dilute phosphorus acid or concentrated phosphoric acid with low solid content is obtained, and the production efficiency and the product quality are both improved.

Description

technical field [0001] The invention belongs to the technical field of phosphoric acid production equipment, and relates to a device for reducing solid impurity content in phosphoric acid production, in particular to a settling tank for continuously separating the solid content of wet-process phosphoric acid. Background technique [0002] Phosphoric acid is an important intermediate chemical product. There are two main types of industrial phosphoric acid production methods. One is thermal method. The obtained phosphoric acid is called thermal phosphoric acid. Because of its high quality and low impurity content, it is mainly used for the production of phosphate , as industrial raw materials or additives; the other type is wet process, and the resulting phosphoric acid is called wet process phosphoric acid, because it contains iron, aluminum, magnesium and other impurities, it is usually used to produce fertilizers. [0003] The obvious feature of the reaction of decomposing ...

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Problems solved by technology

[0006] However, there are some inconvenient places in the existing gravity sedimentation cooling device, such as continuous graded sedimentation cannot be realized, and acid cannot be continuously discharged while feeding acid; the slag after sedimentation cannot be completely discharged, and it is easy to be blocked, causing the mud scraper to lock up , it is necessary to shut down the acid sinking device to clean it, which affects the production efficiency; there is only one acid outlet, and the solid content is not easy to control; the container can hardly cool down, and the acid insoluble matter dissolved in the acid cannot be effectively separated

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