Compound coagulant used for treating rare-earth highly concentrated ammonian wastewater to recover industry ammonium chloride and treatment method

An ammonia nitrogen wastewater and coagulant technology, applied in chemical instruments and methods, ammonium halide, separation methods, etc., can solve problems such as reducing product purity, affecting the quality and sales of recovered ammonium salt products, and poor removal of impurities. Easy to handle, stable and non-toxic sludge volume, simple and easy to handle

Inactive Publication Date: 2009-10-14
GUANGZHOU INST OF GEOCHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Recovering ammonium salt (ammonium chloride) by evaporation and crystallization can offset equipment operating costs, but due to the high content of oils, extractants, heavy metals and other impurities in wastewater, traditional sodium hydroxide is used as a precipitant to remove heavy metals and evaporate to crystallize , although most of the heavy metals can be removed, sodium is also introduced at the same time, which reduces the product purity and seriously affects the quality and sales of recovered ammonium salt products. The removal effect of heavy metals and other impurities is poor, and the recovered products should only be agricultural grade, and the price of agricultural grade ammonium chloride sold on the market is only half of the industrial grade, so how to reduce impurities in wastewater during pretreatment, so that It will be a very economical treatment method to recover industrial grade ammonium chloride after evaporation and crystallization

Method used

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  • Compound coagulant used for treating rare-earth highly concentrated ammonian wastewater to recover industry ammonium chloride and treatment method

Examples

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Effect test

Embodiment 1

[0021] Weigh 600g of ammonium oxalate, 200g of ammonium sulfate, 200g of heavy metal precipitant DTCR and 3g of PAM respectively, and then dissolve them in 13L of water in turn, stir and mix evenly to prepare a composite coagulant with a total mass concentration of 7.1%.

Embodiment 2

[0023] Weigh 450g of ammonium oxalate, 150g of ammonium sulfate, 200g of heavy metal precipitant DTCR and 2g of PAM respectively, and then dissolve them in 13L of water in turn, stir and mix evenly to prepare a composite coagulant with a total mass concentration of 5.8%.

[0024] The embodiment of the treatment method of using composite coagulant to process rare earth high concentration ammonia nitrogen wastewater to reclaim industrial grade ammonium chloride is as follows:

[0025] The numbers of the composite coagulants prepared in the above two application examples are sequentially No. 1 composite coagulant and No. 2 composite coagulant for treating sewage. The wastewater is taken from rare earth soap wastewater and ammonium bicarbonate precipitation mother liquor in a rare earth smelter, and its water quality characteristics are as follows:

[0026] Table 1 Rare earth soap wastewater water quality (pH=0.47, [Cl - ]=96800mg / L, the unit is mg / L)

[0027] NH 4 +...

Embodiment 3

[0031] a. Take 1m 3 The rare earth soap wastewater first enters the inclined plate grease trap, and the residence time of the wastewater is 2.5h, so that the slick oil in the rare earth wastewater and the larger oil droplets in the dispersed oil rise to the surface, scrape off the upper layer of slick oil, and then the wastewater enters the jet type The air flotation chamber is used to remove the emulsified oil and hydrophobic fine solid suspended matter in the wastewater by air flotation. After this step, the content of oil and extractant is 80mg / L.

[0032] b, the waste water after degreasing enters the pH adjustment sedimentation tank, then adding 16L concentration to the waste water is 30% strong ammonia water to adjust the pH to 8, then adds 1.5g PAM to the waste water and stirs the reaction for 15min, and leaves standstill for 40min, resulting in The sludge is discharged through the sludge discharge pipe at the bottom of the tank, and the supernatant and sludge filtrate ...

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Abstract

The invention provides a compound coagulant used for treating rare-earth highly concentrated ammonian wastewater to recover industry ammonium chloride and a treatment method, belonging to the technical field of chemical environment protection and resource recovery. The compound coagulant is a mixed liquor of ammonium oxalate, ammonium sulphate, heavy metal precipitator DTCR and polyacrylamide (PAM). The treatment method for treating wastewater by using the compound coagulant comprises the following steps: firstly, oil substances in the wastewater are removed through a separation tank and an air floating chamber; secondly, the wastewater enters a pH adjusting precipitation tank to adjust the pH value to be 7.5-8.5; thirdly, the wastewater enters a coagulative precipitation tank, the compound coagulant is added, the wastewater after being coagulated and precipitated enters the pH adjusting precipitation tank to adjust the pH value to be 2.5-4, the wastewater after being adjusted the pH value enters an active carbon filter tower to be absorbed and filtered and then is evaporated and concentrated under the condition of negative pressure. The compound coagulant has simple treatment method, low cost and good effect. The treatment method has short process and simple and easy treatment, not only solves the problem of the pollution of the highly concentrated ammonian wastewater, but also achieves the purpose of recovering valuable materials.

Description

technical field [0001] The invention relates to a coagulant and a treatment method that can be used for treating rare earth high-concentration ammonia nitrogen wastewater to recover industrial-grade ammonium chloride, and belongs to the technical fields of chemical environmental protection and resource recovery. Background technique [0002] Rare earth wet smelting adopts extraction process to separate components. This process requires a large amount of lye to participate in the reaction. Considering the production cost, most enterprises currently use ammonia water for saponification. If the waste water generated is not treated, it will be discharged directly. It will bring extremely serious ammonia nitrogen pollution to the discharged water. High-concentration ammonia-nitrogen wastewater is the focus and difficulty in the treatment of rare earth smelting enterprises. At present, there are many treatment processes for this type of wastewater. The mature technologies and meth...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F1/52C02F9/02C02F1/40C02F1/24C02F1/28C01C1/16
Inventor 黄海明肖贤明晏波
Owner GUANGZHOU INST OF GEOCHEMISTRY - CHINESE ACAD OF SCI
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