CN101628764A

CN101628764A - Processing method of industrial waste water generated in hydrometallurgical process of nickel, cobalt and copper

Info

Publication number: CN101628764A
Application number: CN200910101006A
Authority: CN
Inventors: 杨仁武; 陈红星
Original assignee: Zhejiang Huayou Cobalt Co Ltd
Current assignee: Zhejiang Huayou Cobalt Co Ltd
Priority date: 2009-07-30
Filing date: 2009-07-30
Publication date: 2010-01-20
Anticipated expiration: 2029-07-30
Also published as: CN101628764B

Abstract

The invention discloses a processing method of industrial waste water generated in the hydrometallurgical process of nickel, cobalt and copper. A lime cream neutralization and hydrolysis precipitation method is mostly used at present, though the lime cream neutralization and hydrolysis precipitation method has low operation cost, the lime cream neutralization and hydrolysis precipitation method has large slag quantity and a COD value can hardly reach the standard. The processing method comprises the following steps: (1) mixing polymeric ferric sulfate with water to obtain a solution with the mass concentration of 10-35 percent, and maturing the solution; (2) adding a NaOH solution into the industrial waste water to be processed, which contains the nickel, the cobalt and the copper, and regulating the pH value of the industrial waste water to 9-12; (3) adding the polymeric ferric sulfate solution into the industrial waste water for stirring; (4) filtering and separating, i.e. filtering out heavy metal ions, suspended matters and oil type matters; (5) regulating the pH value of a filtering solution to 4-9, adding an oxidant to oxidize to reduce the COD value of the filtering solution; and (6) regulating the pH value of the filtering solution, which is obtained from the step (5), to 6-9. The invention has low operation cost, small slag quantity and easy and convenient useful metal recovery, and the heavy metal ions, the oil type matters, the suspended matters and the COD value all reach the third grade discharge standard of the industrial waste water.

Description

A kind of method of handling nickel, cobalt, copper industrial waste water generated in hydrometallurgical process

Technical field

The present invention relates to the processing method of industrial waste water that nickel, cobalt, copper hydrometallurgy are produced.

Background technology

The trade effluent that the oxyhydroxide (carbonate) of leaching in nickel, cobalt, the copper wet smelting process, purification, extraction, cobalt nickel is synthetic, electrodeposition produced, generally in several mg/litre, tens mg/litre even hundreds of mg/litre scope, the COD value is generally also at 300-1000mg/L for heavy metal ion.

Handle the milk of lime neutralizing hydrolysis precipitator method that above-mentioned trade effluent adopts less expensive mostly at present, make heavy metal ion separate precipitation by following reaction water:

MeSO ₄+Ca(OH) ₂＝Ca?SO ₄↓+Me(OH) ₂↓。

Waste water after milk of lime is handled enters sewage plant through sedimentation or after filtering.Though this kind method running cost is low, the quantity of slag is big, and COD is difficult to up to standard.

Tradition is handled nonferrous smelting waste water with sulphide precipitation, removes heavy metal ion.In waste water, add Na ₂S, the metallic sulfide that makes heavy metal ion generate indissoluble precipitates and removes.Because the sulfide solubility product of heavy metal ion is very little, heavy metal ion is thoroughly removed from waste water, thereby reach the emission standard of heavy metal.The advantage of this method is that the quantity of slag is few, easily dehydration, and waste residue heavy metal content height helps metal recovery, but the work on the spot environment of sulphide precipitation is poor, and increased S in the sewage ^2-Ion causes second environmental pollution, and the COD in industrial wastewater value also slightly rises.

Summary of the invention

Technical problem to be solved by this invention is to overcome the defective that above-mentioned prior art exists, a kind of method that adopts bodied ferric sulfate-NaOH coagulant sedimentation to handle nickel, cobalt, copper industrial waste water generated in hydrometallurgical process is provided, makes heavy metal ion, COD value all reach three grades of emission standards of trade effluent.

For this reason, the technical solution used in the present invention is: a kind of method of handling nickel, cobalt, copper industrial waste water generated in hydrometallurgical process, its step is as follows: 1) bodied ferric sulfate (hereinafter to be referred as PFS) is mixed with the solution that mass concentration is 10-35% with tap water, ageing 4-20h is to improve flocculating effect; 2) trade effluent to pending nickeliferous, cobalt, copper adds NaOH solution, and adjust pH transfers to 9-12, to guarantee the heavy metal ion precipitation fully; 3) in trade effluent, add polymeric ferrous sulphate solution, stir, when the pH of solution value is on the low side, also need adds NaOH and keep the pH value at 9-12; 4) filtering separation filters heavy metal ion, suspended substance and petroleum substance, can reach emission standard; 5) the filtrate adjust pH is to 4-9, and the oxidizer oxidation reduces the COD value of filtrate, and the COD value can reach 100-450mg/L; 6) pH value of filtrate that the step obtains on the accent is to 6-9, and waste water can reach three grades of emission standards of trade effluent.

Above-mentioned method, oxygenant is selected NaClO for use ₃, in NaClO, Sodium Persulfate or the hydrogen peroxide one or more; Because PFS is the polymkeric substance of high price iron, behind the adding PFS, COD can obviously be reduced to 100-150mg/L, and its amount ratio is less, and general consumption is the PFS solid that per 100 cubic metres waste water adds 5-10kg.

The present invention adds NaOH solution earlier and regulates the pH value in the trade effluent that contains cobalt, nickel, copper, add the good PFS solution of ageing in advance again, the effect of PFS solution: the one, play precipitating action, subsalt with a kind of complexity of nickel (cobalt, copper) generation, and the precipitation pH value of this subsalt is more much lower than the precipitation pH value of nickel hydroxide (cobalt, copper), adjust the pH value to 9-12 (optimum value 9.5-10.5), can heavy metal precipitation is complete; The 2nd, play throwing out, in water, form the Fe (OH) of positively charged because of unreacted PFS ²⁺, Fe (OH) ₂ ⁴⁺Deng, and Ni ²⁺Subsalt etc. heavy metal ion and PFS generation is electronegative, and the two neutralizes mutually, and fine particle just flocculates and grows up, and reaches the purpose of precipitate and separate.

The present invention has the following advantages:

1, equipment there is not particular requirement, reduced investment, day processing 1000M ³Sewage investment 50-80 gets final product for ten thousand yuan; 2, running cost is low, 1 yuan/M of working cost ³About; 3, Xian Chang good work environment, non-secondary pollution; 4, the quantity of slag is few, and useful metal reclaims easy (particularly nickel), and acid is molten promptly recyclable; 5, heavy metal ion, petroleum substance, suspended substance and COD all reach three grades of emission standards of trade effluent.

The present invention is further illustrated below in conjunction with embodiment.

Embodiment

It is 10～35% solution that commercially available solid PFS is mixed with mass concentration with tap water, ageing 4-20h.Preset contains the pH value 9-12 of the trade effluent of cobalt, nickel, copper, add pre-configured PFS solution, when the pH of solution value is on the low side, also need add NaOH keeps the pH value at 9-12, reacted 20～30 minutes, filtering separation filters heavy metal ion, suspended substance and petroleum substance, filtrate is transferred pH to 4-9, adds oxygenant (NaClO ₃, NaClO, Sodium Persulfate, ozone etc.) COD falls in oxidation, transfers pH value of filtrate can discharge to 6-9 again, the detected result of processed waste water sees Table 1-3 (handling the result that three types waste water obtains with the present invention).

Table 1: the waste water that heavy metal ions in wastewater content and COD are all higher

Unit: mg/L

Project	??Ni	??Co	??Cu	??Pb	??S ^2-	Petroleum-type	??COD	??pH
Project	??Ni	??Co	??Cu	??Pb	??S ^2-	Petroleum-type	??COD	??pH	Before the processing	??15	??5	??10	??1	??＜1.0	??10	??785	??11
After the processing	??0.7	??0.6	??0.5	??0.5	??＜1.0	??＜3.0	??350	??7.5	Before the processing	??15	??5	??10	??1	??＜1.0	??10	??785	??11

Table 2: heavy metal ions in wastewater content and COD＜500mg/L

Unit: mg/L

Project	??Ni	??Co	??Cu	??Pb	??S ^2-	Petroleum-type	??COD	??pH
Project	??Ni	??Co	??Cu	??Pb	??S ^2-	Petroleum-type	??COD	??pH	Before the processing	??25	??15	??8	??1	??＜1.0	??5	??350	??10.5
After the processing	??＜1.0	??＜1.0	??＜0.5	??0.5	??＜1.0	??＜2	??180	??8.0	Before the processing	??25	??15	??8	??1	??＜1.0	??5	??350	??10.5

Table 3: heavy metal ions in wastewater content is lower

Unit: mg/L

Project	??Ni	??Co	??Cu	??Pb	??S ^2-	Petroleum-type	??COD	??pH
Project	??Ni	??Co	??Cu	??Pb	??S ^2-	Petroleum-type	??COD	??pH	Before the processing	??3	??2	??5	??＜1.0	??＜1.0	??5	??560	??10.5
After the processing	??0.5	??0.5	??0.5	??＜1.0	??＜1.0	??＜2	??360	??8.0	Before the processing	??3	??2	??5	??＜1.0	??＜1.0	??5	??560	??10.5

The above only is preferred embodiment of the present invention.Every foundation technical spirit of the present invention all falls within the scope of protection of the present invention any simple modification, equivalent variations and modification that above embodiment did.

Claims

1, a kind of method of handling nickel, cobalt, copper industrial waste water generated in hydrometallurgical process, its step is as follows: 1) the bodied ferric sulfate water is mixed with the solution that mass concentration is 10-35%, ageing; 2) trade effluent to pending nickeliferous, cobalt, copper adds NaOH solution, and adjust pH is to 9-12; 3) in trade effluent, add polymeric ferrous sulphate solution, stir; 4) filtering separation filters heavy metal ion, suspended substance and petroleum substance; 5) the filtrate adjust pH is to 4-9, and the oxidizer oxidation reduces the COD value of filtrate; 6) transfer pH value of filtrate that the 5th step obtained to 6-9.

2, method according to claim 1 is characterized in that in the 2nd step, add polymeric ferrous sulphate solution after, when the pH of solution value is on the low side, adds NaOH and remain on 9-12 to the pH value of solution.

3, method according to claim 1 and 2 is characterized in that adding in every cubic metre the trade effluent ferric polysulfate solid of 0.05kg-0.10kg.

4, method according to claim 3 is characterized in that described oxygenant selects NaClO for use ₃, in NaClO, Sodium Persulfate or the hydrogen peroxide one or more.