CN101665869A

CN101665869A - Method for highly concentrating metal solution in wet metallurgy

Info

Publication number: CN101665869A
Application number: CN200910042318A
Authority: CN
Inventors: 李振峰; 罗萍; 陈洪景; 虞美辉; 卢伯福; 林志华; 王伟; 张辉; 雷细良
Original assignee: XIAMEN STARMEM FILM TECHNOLOGY Co Ltd
Current assignee: XIAMEN STARMEM FILM TECHNOLOGY Co Ltd
Priority date: 2009-08-31
Filing date: 2009-08-31
Publication date: 2010-03-10

Abstract

The invention discloses a method for highly concentrating a metal solution in wet metallurgy, mainly comprising steps of nano-filtration concentration and penetration concentration of the metal solution, penetrant recycling and the like. As a novel method for concentrating metal solution films in wet metallurgy, the method adopts a penetration film technology to highly concentrate the metal solution, and a penetrant (NH3-CO2) is recycled by column distill. Compared with the prior art like distill concentration, the invention enhances the cyclw of concentration, reduces energy consumption and decreases production cost.

Description

Method for highly concentrating metal solution in a kind of hydrometallurgy

Technical field

The present invention relates to a kind of hydrometallurgy industry concentration method, particularly relate to a kind of employing membrane technique method for highly concentrating metal solution in hydrometallurgy

Background technology

Concentrating is the production operation that often runs in the hydrometallurgy, and concentration method commonly used in the metallurgical industry mainly contains distillation, nanofiltration, reverse osmosis etc., but the following deficiency that these methods also exist:

Distillation method concentrates need expend a large amount of energy, and cost is too high.

Reverse osmosis (RO) or nanofiltration (NF) are a kind of gathering trace ionic effective ways, and be remarkable for solution environmental issue and the effect of raising noble metal material yield, but be subjected to osmotic pressure influence, and it is limited that its enrichment concentrates the upper limit.

Electrodialysis (ED) also is a kind of method of concentrated salts solution, salts solution can obtain thin liquid and dope two portions after by electrodialysis, but water can make the dope dilution by the counter osmosis of ionic membrane, therefore the raising of concentrating degree is inevitable is cost to improve energy consumption, and the concentrated limit is limited by the character of film also.

And in recent years, positive infiltration technology is just carrying out the theoretical investigation and the practical exploration of multi-angle, profound level in the world also in continuous development to this technology.Although the commercial applications of forward osmosis membrane is also very limited, it in fields such as food, pharmacy, the energy, especially has a lot of successful trials in the pure desalination of water field, showed its potential using value.Tzahi Y. etc. have introduced positive infiltration technology principle and some implementation methods being entitled as " Forward osmosis:Principles, applications, and recent developments ".

Summary of the invention

Method for highly concentrating metal solution is the defective at processing methodes such as the concentrated employing of present various hydrometallurgy factory's metallic solutions distillation method in a kind of hydrometallurgy of the present invention, as directly use steam concentrated cost height for some low concentration solutions, reverse osmosis, nanofiltration, electrodialytic technique realization concentrate it and have shortcomings such as of poor benefits, that difficulty is big, cycles of concentration is limited.The present invention proposes a kind of improved film for this reason and handle the hydrometallurgy method for highly concentrating metal solution, so that metallic solution realizes that under the less energy-consumption condition it is carried out high multiple concentrates, but the also purpose of reuse of while dialyzate.Adopt nanofiltration and positive infiltration technology combination in the inventive method, the characteristics of just permeating are need not external pressure, and it is low consume energy, and film pollutes little, is one of main direction of developing of following application of membrane.

The present invention program improves this processing method at above problem, after metallurgical metallic solution concentrates through preliminary nanofiltration low power, increase by a step forward osmosis membrane concentration technique, carry out high multiple and concentrate, make that concentration of heavy metal ion reaches in the metallic solution and smelt electrolytic requirement, and then carry out next step and smelt electrolysis, improve the utilization ratio of metals resources and water resources, realize the low pollution of waste water in environmental protection, the usury usefulness of resource has reduced energy consumption.

For overcoming the above problems, the technical solution adopted in the present invention comprises the steps:

(1) nanofiltration concentrates: pretreated hydrometallurgy metallic solution is pumped into the rolled film nanofiltration system, obtain concentrated solution and dialyzate.The spissated main purpose of nanofiltration is with the monovalent ion such as the Na that remove in the metallic solution ⁺, F ^-, Cl ^-Deng; F ^-, Cl ^-Removal can alleviate the corrosion of electrowinning process to equipment; The removal of monovalent salt simultaneously also can reduce the osmotic pressure of concentrated solution, reduce next step just permeating in the usage quantity of permeate agent; And can carry out low power to metallic solution concentrates;

(2) just permeating concentrated: after will concentrating through nanofiltration concentrated solution pump into positive osmosis system, dialyzate adds permeate agent (NH ₃-CO ₂), carrying out high density and concentrate, concentrated solution directly enters in next step the electrolysis workshop section;

(3) post distillation: the recovery of permeate agent can be reclaimed by simple post distillation mode, and the pure water that the post fractionation by distillation goes out also can direct reuse.

The film that nanofiltration system is selected for use described in the step (1) is that molecular weight cut-off is the daltonian polysulfones of 150-300, polyethersulfone, composite nanometer filtering film, and three layers of composite membrane of nanofiltration, equipment are rolling nanofiltration separation equipment, and service temperature is a normal temperature, and working pressure is 2.0-3.5Mpa;

Positive osmosis system selects for use film for just permeating CTA film (tri acetic acid fiber film) described in the step (2); Selected permeate agent is high molten gaseous ammonia and carbonic acid gas combination (being NH3-CO2), and permeate agent concentration is 2-10mol/L.

Used permeate agent recovery system is the post distillation plant in the step (3), and temperature is 50-70 ℃.

The present invention concentrates than traditional distillation, reverse osmosis, nanofiltration etc., and the advantage that is had is as follows:

(1) cycles of concentration height: can reach in the metallurgical electrolysis operation requirement to metal ion high density in the electrolytic solution;

(2) energy consumption is low: just permeating and need not pressure-driven, just can realize concentration process;

(3) cost is low: permeate agent is the heat sensitization compound, and only needing simple heating to decompose just can recycling;

(4) water saving: the dialysis water in the process all can also all reclaim application.

(5) F in the other nano-filtration step ^-, Cl ^-Part remove, can effectively minimizing electrowinning process in the corrosion of electrolyzer.

Description of drawings

Fig. 1 is a method flow diagram of the present invention.

Embodiment:

Be elaborated below in conjunction with Fig. 1 and embodiment:

Certain mining and metallurgy enterprise selects zinc (Zn in the silver metal solution ²⁺) content is about 10g/L, conventional concentrating is to adopt distillation to concentrate the energy consumption height.Adopt the step of production method of the present invention as follows: (1) nanofiltration concentrates: nanofiltration membrane adopts three layers of composite membrane of proprietary nanofiltration, molecular weight cut-off is 150～300 dalton (calculating with neutral molecule), service temperature is a normal temperature, working pressure 2.75Mpa, the average film flux is 19.6LMH, zine ion can be concentrated into about 55g/L, cycles of concentration is (to see Table 1) about 5.5 times.As shown in Table 2, though concentrated more than 6 times the F in the concentrated solution ^-, Cl ^-Concentration does not have significant enrichment.

Batch	Stock liquid (g/L)	Dialyzate (g/L)	Concentrated solution (g/L)	Cycles of concentration
Batch	Stock liquid (g/L)	Dialyzate (g/L)	Concentrated solution (g/L)	Cycles of concentration	??1	??10.1	??1.67	??56	??6.4
??2	??10.5	??1.77	??57	??6.3	??1	??10.1	??1.67	??56	??6.4
??2	??10.5	??1.77	??57	??6.3	??3	??9.8	??2.07	??54	??6.7
??4	??9.7	??1.73	??55	??6.7	??3	??9.8	??2.07	??54	??6.7

Table 1: nanofiltration concentrates Zn ²⁺The concentration experimental data

Table 2: nanofiltration concentrates F ^-, Cl ^-Experimental data

(2) just permeating concentrated: the concentrated solution after nanofiltration concentrates pumps into the forward osmosis membrane system, and forward osmosis membrane adopts the CTA film to add permeate agent in the dialysis side, and permeate agent concentration is 8mol/L, osmotic pressure 18Mpa.To Zn ²⁺Solution carries out high multiple and concentrates, and works as Zn ²⁺Ionic concn reaches about 130g/L and (sees Table 3), when reaching hydrometallurgy electrowinning process section concentration requirement, enters electrowinning process.

Batch	Stock liquid (g/L)	Concentrated solution (g/L)	Membrane flux (LMH)
Batch	Stock liquid (g/L)	Concentrated solution (g/L)	Membrane flux (LMH)	??1	??56	??135	??19
??2	??57	??138	??17	??1	??56	??135	??19
??2	??57	??138	??17	??3	??54	??130	??18
??4	??55	??129	??19	??3	??54	??130	??18

Table 3: just permeating concentrated data

(3) post distillation: the osmotic agent solution after will dilute is passed through the post Distallation systm, and 60 ℃ of temperature are to permeate agent (NH ₃-CO ₂) recycle.

(4) water that the spissated dialyzate of nanofiltration and post fractionation by distillation are gone out is incorporated in the tank, can return smelting shop and reuse.

Claims

1. method for highly concentrating metal solution in the hydrometallurgy is characterized in that comprising the steps:

(1) nanofiltration concentrates: pretreated hydrometallurgy metallic solution is pumped into rolling nanofiltration membrane system, carry out lower concentration and concentrate, obtain dialyzate and concentrated solution respectively;

(2) just permeating concentrated: nanofiltration is concentrated the concentrated solution obtain pump into the forward osmosis membrane system, dialyzate adds an amount of permeate agent (NH ₃-CO ₂), carry out high density and concentrate, obtain concentrated solution respectively and contain the permeate agent dialyzate;

(3) post distillation: contain the permeate agent dialyzate and adopt the post distillating method that permeate agent is recycled.

2. method for highly concentrating metal solution in a kind of hydrometallurgy according to claim 1, it is characterized in that in the step 1), the selected film of described nanofiltration membrane system is that molecular weight cut-off is the daltonian polysulfones of 150-300, polyethersulfone, composite nanometer filtering film, three layers of composite membrane of nanofiltration, selected device type is the rolled film separating device, described nanofiltration concentration operation condition is a normal temperature, working pressure 2.0～3.5MPa.

3. method for highly concentrating metal solution in a kind of hydrometallurgy according to claim 1, it is characterized in that step 2) in, the selected film of described positive osmosis system is cellulosetri-acetate (CTA) film, and selected permeate agent is that high molten gaseous ammonia and carbonic acid gas combination (are NH ₃-CO ₂), permeate agent concentration is 2-10mol/L.

4. method for highly concentrating metal solution in a kind of hydrometallurgy according to claim 1 is characterized in that permeate agent recovery system used in the step 3) is the post distillation plant, and temperature is 50-70 ℃.