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Treatment of ammonium chloride waste-water zero-displacement in rare-earth production

A treatment method and ammonium chloride technology, applied in the field of ammonium halide, can solve the problems of high impurity content of solid ammonium chloride, difficult to obtain application prospects, low economic benefits, etc. The process is simple and reasonable, and the effect of improving production efficiency

Inactive Publication Date: 2006-05-31
HANGZHOU WATER TREATMENT TECH DEV CENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method of reclaiming ammonium chloride from ammonium chloride-containing waste water in the form of solid ammonium chloride consumes a lot of energy during the phase change process of reclaiming ammonium chloride and removing a large amount of water: and the recovered solid ammonium chloride impurity High content, low use value: used as chemical fertilizer, long-term use will cause soil salinization, and used as chemical raw material, because of poor purity, low economic benefit; moreover, ammonium chloride solution is highly corrosive, and it will increase the temperature and concentration Under these conditions, the requirements for equipment materials are very high, which makes it difficult for these methods to obtain good application prospects.

Method used

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  • Treatment of ammonium chloride waste-water zero-displacement in rare-earth production
  • Treatment of ammonium chloride waste-water zero-displacement in rare-earth production

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] The process equipment and process of this example are as follows: figure 1 shown. The above-mentioned rare earth ore ammonium chloride wastewater is first purified and pretreated, and 5 tons of water liquid (its wastewater sampling composition is shown in Table 1) is input into the raw water tank 1 through flocculation, filtered in the multimedia filter 3 to remove impurities, activated carbon filter 4 Medium adsorption filtration, the water pollution index SDI of the effluent is ≤4.8. The flocculant is polyacrylamide, which is filtered through the secondary fine filter 6 to remove impurities. Then pump into the first-stage reverse osmosis devices 7 and 8, desalination and concentration are carried out at a pressure of 3.2Mpa and a water temperature of 15°C. This is an 8" roll-type composite membrane reverse osmosis brackish water desalination device, and its structure is a double reverse osmosis device. , the compound structure section is set as the front and back tw...

Embodiment 2

[0040] The ammonium chloride wastewater produced by a rare earth company in Northwest China has undergone chemical sedimentation, softening, filtration, and activated carbon adsorption. The water quality analysis report is shown in Table 2.

[0041] serial number

[0042] The pretreatment method is the same as Example 1. At an inlet water temperature of 31.5°C and an operating pressure of 5.0Mpa, a 2.5" membrane module is used, and the rest of the process flow is the same as Example 1. See figure 2 . When the permeate flux of the third-stage reverse osmosis device is 400mL / min, the concentration of ammonium chloride in the concentrate is 68046.2mg / L, and the concentration of the permeate is 16mg / L. The ammonium chloride concentrated solution concentrated by the above-mentioned reverse osmosis was passed through the solution, and the ammonia was distilled to obtain ammonia water with a concentration of 6.2 mol / L.

Embodiment 3

[0045] The ammonium chloride wastewater produced by a rare earth factory in Northwest China was subjected to chemical sedimentation, softening, filtration, and activated carbon adsorption similar to Example 2. The water quality analysis report is shown in Table 3.

[0046] At an inlet water temperature of 36.5°C and an operating pressure of 6.5Mpa, a 2.5″ membrane module is used, and the process flow is the same as Example 1. When the permeate flux of the third-stage reverse osmosis device is 560mL / min, the concentration of the concentrated solution is 83312mg / L. The liquid concentration is 18mg / L. The above-mentioned reverse osmosis concentrated ammonium chloride solution is passed through a three-effect evaporator, and after it is concentrated to 11%, it is passed through an ammonia distillation absorption tower, and saturated Ca(OH) 2 Solution, distill ammonia to obtain the ammoniacal liquor of 6.5mol / L concentration. No waste discharge.

[0047] The treatment metho...

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Abstract

A treatment of ammonia chloride waste-water zero discharge in rare earth production is carried out by taking waste water containing ammonia chloride as object, chemically and physically purifying, membrane separation treating by secondary or tertiary or multi-stage inverse penetration device, evaporation concentrating for concentrate, steaming ammonia to obtain ammonia water, recovering calcium chloride product, and split flowing dialyzate to recover. It achieves low cost, energy saving, simple process and zero discharge.

Description

technical field [0001] The invention relates to ammonium halides, industrial waste water treatment and recycling of resources. Specifically, it is a method of using membrane technology to treat ammonium chloride wastewater, recover ammonia water, and realize zero discharge. Background technique [0002] At present, the discharge of waste water containing ammonium chloride exists in large quantities in the rare earth industry and the production process of potassium carbonate produced by ion exchange, and its concentration varies from 0.1-10%. As we all know, the direct discharge of wastewater containing ammonium chloride causes the loss of precious water and chemical raw materials such as ammonium chloride, which not only causes a serious waste of resources, but also brings serious pollution and poses a serious threat to the human ecological environment. Moreover, the concentration of ammonium chloride in the waste water fluctuates greatly, the wa...

Claims

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Application Information

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IPC IPC(8): C02F9/04C02F1/40C02F1/44C02F1/52C02F1/58
Inventor 薛德明胡亚芹王力宁黄宝能
Owner HANGZHOU WATER TREATMENT TECH DEV CENT
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