# US 11,078,100 B2 · Method for treating wastewater in the spherical nickel hydroxide production process

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- Number: US 11,078,100 B2
- Document ID: US11078100B2
- Status: Granted
- Kind: B2
- Application number: 16/635,279
- Filed: 2018-07-23
- Published: 2021-03-25
- Granted: 2021-08-03
- Earliest claimed: 2017-07-31
- Assignees: Sichuan SiDaNeng Envrionmental Protection Technology Co., Ltd.
- Applicants: Dingjiang Guo; Zhi He; Jinsong He; Chao Liu; Xiangting Cai
- Inventors: Dingjiang Guo; Zhi He; Jinsong He; Chao Liu; Xiangting Cai
- Web page: https://patentgrep.com/patent/US11078100B2

## CPC

- C02F 9/00: Multistage treatment of water, waste water or sewage
- B01D 11/028: {Flow sheets}
- B01D 19/00: Degasification of liquids
- B01D 36/00: Filter circuits or combinations of filters with other separating devices
- B01D 53/58: Ammonia
- B01D 61/58: Multistep processes
- C01C 1/02: Preparation, {purification} or separation of ammonia
- B01D 2311/2649: Filtration
- B01D 2311/2653: Degassing
- C02F 1/001: {Processes for the treatment of water whereby the filtration technique is of importance (C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00)}
- C02F 1/04: by distillation or evaporation
- C02F 1/441: {by reverse osmosis}
- C02F 1/442: {by nanofiltration}
- C02F 1/444: {by ultrafiltration or microfiltration}
- C02F 1/66: by neutralisation; pH adjustment (for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58)
- C02F 2101/16: Nitrogen compounds, e.g. ammonia
- C02F 2103/16: from metallurgical processes, i.e. from the production, refining or treatment of metals, e.g. galvanic wastes
- C02F 2103/34: from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
- C02F 2301/08: Multistage treatments, e.g. repetition of the same process step under different conditions
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C01C: AMMONIA; CYANOGEN; COMPOUNDS THEREOF ({metal hydrides, monoborane, diborane or addition complexes thereof C01B6/00}; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; azides C01B21/08; {compounds other than ammonia or cyanogen, containing nitrogen, non-metals and optionally metals C01B21/082}; metal imides or amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; compounds containing silicon C01B33/00; compounds containing boron C01B35/00)

## Abstract

The invention discloses a method for treating wastewater generated in the spherical nickel hydroxide production process. The invention uses a combined membrane treatment process to systematically and specifically treat process wastewater produced at all stages of the spherical nickel hydroxide preparation process. The concentration of crude wastewater greatly reduces the treatment burden and energy consumption in the evaporation process with obvious environmental protection benefits. In addition, the membrane treatment system has the characteristics of easy control and simple operation. By virtue of the treatment method of the invention, the quality of some produced water can meet the standard of purified water.

## Claims

### Claim 1

A method for treating wastewater generated during a spherical nickel hydroxide production process having an extraction stage, a filtering stage and an elution stage, the wastewater treatment method characterized by comprising the following steps:
a. introducing raffinate from an extraction stage in the spherical nickel hydroxide production process into a primary membrane concentration and filtration system (1), which outputs primary concentrate and primary clear liquid after concentrating and filtering the raffinate;
b. introducing spherical nickel hydroxide mother liquid from a filtering stage in the spherical nickel hydroxide production process into a secondary membrane concentration and filtration system (2), which outputs secondary concentrate and secondary clear liquid after concentrating and filtering the spherical nickel hydroxide mother liquid;
c. introducing spherical nickel hydroxide eluent from an elution stage in the spherical nickel hydroxide production process into a tertiary membrane concentration and filtration system (3), which outputs tertiary concentrate and tertiary clear liquid after concentrating and filtering the spherical nickel hydroxide eluent;
d. introducing the primary concentrate output in Step a into an evaporation system (5);
e. introducing the secondary concentrate output from the secondary membrane concentration and filtration system (2) in Step b and the tertiary concentrate output from the tertiary membrane concentration and filtration system (3) in Step c into an ammonia recovery system (4) for ammonia recovery, said ammonia recovery system to output a residual liquid; and
f. introducing the residual liquid from the ammonia recovery system (4) in Step e into the evaporation system (5).

### Claim 2 (depends on 1)

The method for treating wastewater generated during the spherical nickel hydroxide production process according to claim 1, characterized in that the primary clear liquid in Step a, the secondary clear liquid in Step b, and the tertiary clear liquid in Step c are used as eluent sources for the elution stage in the spherical nickel hydroxide production process.

### Claim 3 (depends on 1)

The method for treating wastewater generated during the spherical nickel hydroxide production process according to claim 1, characterized in that ammonia gas from a gas outlet of the ammonia recovery system (4) in Step e is used as an ammonia gas supply source for a preparation reaction stage of the spherical nickel hydroxide production process.

### Claim 4 (depends on 1)

The method for treating wastewater generated during the spherical nickel hydroxide production process according to claim 1, characterized in that each of the primary membrane concentration and filtration system (1), the secondary membrane concentration and filtration system (2) and the tertiary membrane concentration and filtration system (3) comprises an ultrafiltration membrane filtration system (61), a nanofiltration membrane filtration system (62) and a multi-stage reverse osmosis membrane filtration system which are sequentially connected;
the raffinate in Step a, the spherical nickel hydroxide mother liquid in Step b and the spherical nickel hydroxide eluent in Step c enter the ultrafiltration membrane filtration system (61) in the respective membrane concentration and filtration systems, filtrate from the ultrafiltration membrane filtration system (61) enters the nanofiltration membrane filtration system (62), filtrate from the nanofiltration membrane filtration system (62) enters the multi-stage reverse osmosis membrane filtration system, concentrate from the multi-stage reverse osmosis membrane filtration system flows back to the nanofiltration membrane filtration system (62) through a liquid inlet of the nanofiltration membrane filtration system (62) for further filtration, and finally the multi-stage reverse osmosis membrane filtration system outputs clear liquid and the nanofiltration membrane filtration system (62) outputs solid waste.

### Claim 5 (depends on 4)

The method for treating wastewater generated during the spherical nickel hydroxide production process according to claim 4, characterized in that the reverse osmosis membrane filtration system of each of the primary membrane concentration and filtration system, the secondary membrane concentration and filtration system and the tertiary membrane concentration and filtration systems is a disk-tube reverse osmosis membrane filtration system.

### Claim 6 (depends on 4)

The method for treating wastewater generated during the spherical nickel hydroxide production process according to claim 4, characterized in that each of the raffinate in Step a, the spherical nickel hydroxide mother liquid in Step b and the spherical nickel hydroxide eluent in Step c are pretreated before entering the ultrafiltration membrane filtration system (61).

### Claim 7 (depends on 6)

The method for treating wastewater generated during the spherical nickel hydroxide production process according to claim 6, characterized in that the pretreatment comprises removing turbidity, cooling and adjusting pH of the raffinate in Step a, the spherical nickel hydroxide mother liquid in Step b and the spherical nickel hydroxide eluent in Step c.

### Claim 8 (depends on 4)

The method for treating wastewater generated in the spherical nickel hydroxide production process according to claim 4, characterized in that the ultrafiltration membrane filtration system (61) of each of the primary membrane concentration and filtration system, the secondary membrane concentration and filtration system and the tertiary membrane concentration and filtration systems is a filtration system for filtering particles of molecular weight >500 and size >0.005 μm.

### Claim 9 (depends on 4)

The method for treating wastewater generated in the spherical nickel hydroxide production process according to claim 4, characterized in that the nanofiltration membrane filtration system (62) of each of the primary membrane concentration and filtration system, the secondary membrane concentration and filtration system and the tertiary membrane concentration and filtration systems is a filtration system for filtering particles of molecular weight of 150-500 and size of 0.0005-0.005 μm.

### Claim 10 (depends on 4)

The method for treating wastewater generated in the spherical nickel hydroxide production process according to claim 4, characterized in that the reverse osmosis membrane filtration system of each of the primary membrane concentration and filtration system, the secondary membrane concentration and filtration system and the tertiary membrane concentration and filtration systems is a filtration system for filtering particles of molecular weight of 50-150 and size of 0.0001-0.001 μm.