CN104451191A - Dilution extraction process capable of improving copper recovery rate - Google Patents

Abstract

The invention provides a dilution extraction process capable of improving the copper recovery rate. In a two-stage countercurrent extraction system of a copper-containing solution, raffinate after first-stage extraction is diluted according to an appropriate proportion, then second-stage extraction is performed, an organic phase in the raffinate is recovered by using an oil separation tank, then neutralization is performed by lime, and the up-to-standard emission is further realized. The process has the advantages of simple process flow, good matching property with an existing process, no increase in equipment investment, no increase in production and operation cost, no influence on technical indexes of the extraction process, capability of effectively improving the extraction recovery rate of copper and reducing loss of copper, and the like. The process can also be popularized and applied to a high-acid leaching solution containing copper materials for extracting copper, the copper-containing high-acid leaching solution is used for leaching in a circulating manner, and part of the high-copper and high-acid leaching solution is discharged by opening a path regularly, diluted appropriately and then used for extracting copper, so that the effects of improving the copper leaching rate by high-acid leaching and improving the copper extraction rate by low-acid extraction are achieved, the problems of copper loss, a large amount of gypsum slag, non-smooth copper extraction process and the like caused by a lime neutralization-extraction process of the high-acid leaching solution can be avoided, and the process has relatively good popularization and application prospects.

Description

Improve the dilution extraction process of copper recovery

One. technical field

The present invention relates to field of chemical metallurgical technology, especially relate to dilution extraction process, specifically a kind of dilution extraction process improving copper recovery.

Two. background technology

Extraction is the committed step of modern wet-milling processing (Leaching-solvent Extraction-electrowinning Technology, L-SX-EW).Along with exploitation that is efficient, stabilized copper extraction agent, the hydrometallurgy of copper obtains huge development.At present, the copper in the whole world 20% is by Extraction electrodeposition explained hereafter.

The principle of copper extraction can utilize following reaction formula to represent:

Extraction process: Cu ²⁺+ 2R-H====R ₂cu+2H ⁺

Stripping process: R ₂cu+2H ⁺====Cu ²⁺+ 2R-H

The reaction formula extracted from copper, the rising of solution acidity, the molecular balance that copper can be caused to extract, toward moving left, is unfavorable for the extraction of copper.

In copper-contained material leaching process, in order to improve the leaching yield of copper, often increasing the sulfuric acid concentration of Leaching Systems, making the sulfuric acid concentration in leach liquor higher, being unfavorable for the extraction of copper.

In current production, for reaching the Optimized Extraction acidity (pH ≈ 2) of copper, the method for limestone vegetation is usually adopted to reduce the sulfuric acid concentration of leach liquor.There is many deficiencies in the method, as carried secretly, in causing the copper of in leach liquor 5% ~ 20% to be lost in and in slag because of generation copper hydroxide precipitation and gypsum tailings; Can produce a large amount of gypsum tailings after limestone vegetation, part gypsum tailings can wear filter when filter press, making extraction feed liquid solids content higher, increasing causing three phasors of extracting system; Meanwhile, limestone vegetation process, can produce a large amount of ferric hydroxide colloids, is unfavorable for the phase process of oil mixing with water phase, also will three phasors of extracting system be caused to increase.

Three. summary of the invention

The object of the invention is the deficiency overcoming existing technique, a kind of dilution extraction process improving copper recovery is provided.This technical process is simple, and good with the matching of existing technique, copper recovery is high.

The know-why that the present invention improves the dilution extraction process of copper recovery is as follows:

1, dilution extraction improves the principle of percentage extraction

Copper extraction process: Cu ²⁺+ 2R-H====R ₂cu+2H ⁺

The equilibrium constant of copper extractive reaction $K=\frac{\left[R_2\mathrm{Cu}\right]\·{\left[H^{+}\right]}^2}{{[R-H]}^2\·\left[{\mathrm{Cu}}^{2+}\right]}$

When copper extraction reaches balance wherein [H ⁺] _o[Cu ²⁺] _obe respectively copper and extract [H when reaching balance ⁺] and [Cu ²⁺] volumetric molar concentration.

When copper extraction reaches balance, add the water that raffinate monoploid is long-pending, then [H in aqueous phase ⁺] and [Cu ²⁺] volumetric molar concentration be reduced to equilibrium concentration [H ⁺] _o[Cu ²⁺] _ogeneral, i.e. [H ⁺]=0.50 [H ⁺] _o, [Cu ²⁺]=0.50 [Cu ²⁺] _o; And R in organic phase ₂the concentration of Cu and R-H is substantially constant.Therefore, after dilution, the value of the reaction business Q of copper extractive reaction is:

$Q=\frac{\left[R_2\mathrm{Cu}\right]\&CenterDot;{\left(\text{0.50}{\left[H^{+}\right]}_o\right)}^2}{{[R-H]}^2\&CenterDot;\left(0.50{\left[{\mathrm{Cu}}^{2+}\right]}_o\right)}=0.50\&times;\frac{\left[R_2\mathrm{Cu}\right]\&CenterDot;{{\left[H^{+}\right]}_o}^2}{{[R-H]}^2\&CenterDot;{\left[{\mathrm{Cu}}^{2+}\right]}_o}={0.50K}^o<K^o$

Q<K ^o, illustrate that after adding the long-pending water dilution of raffinate monoploid, the reaction of the copper extraction of system does not reach balance, and the direction of continuing to augmenting response business (Q) is carried out by copper extractive reaction, copper extractive reaction will to increase [H+] concentration, reduction [Cu ²⁺] direction of concentration carries out, namely continuation is carried out to the right by copper extractive reaction, and extraction of copper will increase.Copper extraction system that Here it is is carried out suitably dilution and is improved the principle of extraction of copper.

2, the calculating of extraction process extraction of copper is diluted

The isothermal Extraction equilibrium constants K of hydroxyl oximes chelated copper extraction agent, generally at 20-100, can be measured by extraction test.

If the sulfuric acid of feed liquid and the volumetric molar concentration of copper are [H when extraction starts ⁺] ₀[Cu ²⁺] ₀, extractant concentration=[R-H] ₀, extraction of copper X ₁.Extract copper mol concentration=[Cu when reaching balance ²⁺] ₀× (1-X ₁), hydrogen ion concentration=[H ⁺] ₀+ 2 × [Cu ²⁺] ₀× X ₁, extractant concentration=[R-H] ₀-2 × [Cu ²⁺] ₀× X ₁, copper extraction complex concentration [R ₂cu]=[Cu ²⁺] ₀× X ₁.Extraction of copper when reaching extraction equilibrium can be calculated according to the equilibrium constant K of copper extraction.

The calculating of extraction of copper is carried out below in conjunction with example:

If the copper Extraction equilibrium constants K=21 of certain copper extractant (molecular-weight average is 270, and density is 0.92g/mL), the sulfuric acid concentration of extraction feed liquid is 6g/L, and copper concentration is 2g/L, and the volumetric concentration of extraction agent is 10%.

Then: the hydrogen ion concentration [H in feed liquid ⁺] ₀=6/49=0.122mol/L, copper ion concentration [Cu ²⁺] ₀=2/64=0.03125mol/L, extractant concentration [R-H] ₀=1000 × 10% × 0.92/270=0.3407mol/L.

When extraction reaches balance, extraction of copper is X1, and the copper concentration in solution is [Cu ²⁺]=0.03125 (1-X ₁), copper extraction complex concentration [R ₂cu]=[Cu ²⁺] ₀× X=0.03125X ₁, hydrogen ion concentration [H ⁺]=[H ⁺] ₀+ 2 × [Cu ²⁺] ₀× X ₁=0.122+0.0625X ₁, extractant concentration [R-H]=[R-H] ₀-2 × [Cu ²⁺] ₀× X ₁=0.3407-0.0625X ₁.

Above data bring equilibrium constant calculation formula into, can obtain:

K＝[Cu ²⁺] ₀×X ₁×([H ⁺] ₀+2×[Cu ²⁺] ₀×X ₁) ²/(([R-H] ₀-2×[Cu ²⁺] ₀×X ₁) ²×[Cu ²⁺] ₀×(1-X ₁))＝0.03125X ₁×(0.122+0.0625X ₁) ²/((0.3407-0.0625X ₁) ²×0.03125(1-X ₁))＝21

By can be calculated, extraction of copper X ₁=98%.

Extraction feed liquid is diluted 1 times, hydrogen ion concentration [H when extraction starts ⁺]=0.50 [H ⁺] ₀=0.06122mol/L, copper concentration [Cu ²⁺]=0.50 [Cu ²⁺] ₀=0.01562mol/L, extractant concentration is constant, i.e. [R-H]=[R-H] ₀=0.3407mol/L.Equilibrium constant K=21.

If extraction of copper is X after dilution.When extraction reaches balance, the copper concentration [Cu in solution ²⁺]=0.5 [Cu ²⁺] ₀× (1-X)=0.01562 (1-X), copper extraction complex concentration [R ₂cu]=0.5 [Cu ²⁺] ₀× X=0.01562X, hydrogen ion concentration [H ⁺]=0.5 [H ⁺] ₀+ 2 × 0.5 [Cu ²⁺] ₀× X=0.06122+0.03125X, extractant concentration [R-H]=[R-H] ₀-2 × 0.5 [Cu ²⁺] ₀× X=0.3407-0.03125X.

Above data bring equilibrium constant calculation formula into, can obtain:

K＝0.5[Cu ²⁺] ₀×X×(0.5[H ⁺] ₀+2×0.5[Cu ²⁺] ₀×X) ²/(([R-H] ₀-2×0.5[Cu ²⁺] ₀×X) ²×0.5[Cu ²⁺] ₀×(1-X))＝0.01562X×(0.06122+0.03125X) ²/((0.3407-0.03125X) ²×0.01562(1-X))＝21

By can be calculated, extraction feed liquid dilutes the extraction of copper X=99.6% after 1 times, is greater than extraction of copper X when not diluting ₁=98%.

Calculation result can clearly show, extraction feed liquid, through suitable dilution, effectively can improve extraction of copper.Copper extraction system that Here it is dilution improves the principle of extraction of copper.

The dilution extraction process that the present invention improves copper recovery adopts following technical scheme:

In copper-containing solution two-stage countercurrent extracting system, the raffinate of one-level extraction after suitable proportion dilution, then carries out second stage extraction, and raffinate utilizes oil partition tank to reclaim organic phase, then standard discharge after limestone vegetation.

Detailed processing condition are as follows:

The raffinate of one-level extraction utilizes new water or backwater dilution;

The amount of new water or backwater is 30% ~ 100% of raffinate;

Raffinate utilizes oil partition tank to reclaim organic phase;

The raffinate reclaimed after organic phase utilizes limestone vegetation to the rear standard discharge of pH 6.0 ~ 9.0.

Per-cent (%) in this specification sheets all refers to mass percent.

The invention has the advantages that:

(1) technical process is simple, good with the matching of existing technique, without the need to increasing facility investment, does not increase production run cost;

(2) extraction after the dilution of one-level raffinate, can not affect extraction process technical indicator.The partial load organic phase obtained also needs to enter one-level extraction, and settling time is guaranteed, and oily water separation is thorough, can not increase the water yield that load organic phases is carried secretly.Raffinate can utilize oil partition tank effectively to reclaim organic phase, can not cause the loss of organic phase;

(3) adopt this technique, effectively can improve the recovery of extraction of copper, reduce the loss of copper;

(4) this technique also can be applied to copper-contained material high acidic oils liquid extracting copper, cupric high acidic oils liquid circulating leaching, the leach liquor of regular part high-copper peracid of opening a way out, carry out the rear extracting copper of suitably dilution, reach the effect that high acidic oils improves copper leaching rate, low acid extraction improves extraction of copper, the problems such as the copper loss that high acidic oils liquid limestone vegetation-extraction process can be avoided to bring is lost, the gypsum quantity of slag is large, copper extraction process has some setbacks, have good popularizing application prospect.

Four. accompanying drawing explanation

Fig. 1 is the process flow sheet that the present invention improves the dilution extraction process of copper recovery.

Five. embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.

As shown in Figure 1, a kind of dilution extraction process improving copper recovery comprises the steps and processing condition:

A, one-level extract, and cupric extraction stoste utilizes the organic phase of partial load to carry out one-level extraction, obtains one-level raffinate and load organic phases, and load organic phases obtains after carrying out back extraction copper regenerating organic phase;

B, one-level raffinate dilute, and one-level raffinate adds the new water of raffinate liquid measure 30% ~ 100% or backwater dilutes;

C, secondary extract, and the one-level raffinate after dilution utilizes regeneration organic phase to carry out second stage extraction, obtains raffinate and partial load organic phase;

D, raffinate process, raffinate utilizes oil partition tank to reclaim organic phase, then standard discharge after limestone vegetation.

Below in conjunction with embodiment, method of the present invention is described further.

Embodiment 1:

Cupric extraction stoste (Cu 2g/L, H ₂sO ₄8g/L), adopt two-stage countercurrent extraction process to reclaim copper, the new water that one-level raffinate adds raffinate liquid measure 30% dilutes, and then carries out second stage extraction, and raffinate copper concentration is reduced to 50mg/L, extraction of copper 96.75%.

Embodiment 2:

Cupric extraction stoste (Cu 2g/L, H ₂sO ₄8g/L), adopt two-stage countercurrent extraction process to reclaim copper, the new water that one-level raffinate adds raffinate liquid measure 50% dilutes, and then carries out second stage extraction, and raffinate copper concentration is reduced to 30mg/L, extraction of copper 97.75%.

Embodiment 3:

Cupric extraction stoste (Cu 2g/L, H ₂sO ₄8g/L), adopt two-stage countercurrent extraction process to reclaim copper, the new water that one-level raffinate adds raffinate liquid measure 100% dilutes, and then carries out second stage extraction, and raffinate copper concentration is reduced to 20mg/L, extraction of copper 98.0%.

Embodiment 4:

Cupric extraction stoste (Cu 2g/L, H ₂sO ₄8g/L), adopt two-stage countercurrent extraction process to reclaim copper, the backwater that one-level raffinate adds raffinate liquid measure 30% dilutes, and then carries out second stage extraction, and raffinate copper concentration is reduced to 60mg/L, extraction of copper 96.10%.

Embodiment 5:

Cupric extraction stoste (Cu 2g/L, H ₂sO ₄8g/L), adopt two-stage countercurrent extraction process to reclaim copper, the backwater that one-level raffinate adds raffinate liquid measure 50% dilutes, and then carries out second stage extraction, and raffinate copper concentration is reduced to 41mg/L, extraction of copper 96.93%.

Embodiment 6:

Cupric extraction stoste (Cu 2g/L, H ₂sO ₄8g/L), adopt two-stage countercurrent extraction process to reclaim copper, the backwater that one-level raffinate adds raffinate liquid measure 100% dilutes, and then carries out second stage extraction, and raffinate copper concentration is reduced to 29mg/L, extraction of copper 97.10%.

Embodiment 7:

Temperatures as high 750 ~ 950 DEG C during the cupric pyrite burning of sulphur content higher (40-45%), leach the copper of calcining with the low-concentration sulfuric acid solution of 10 ~ 20g/L, copper leaching rate only has 20 ~ 30%.Leach the copper of calcining with the high-concentration sulfuric acid solution of 50 ~ 60g/L, copper leaching rate can up to 60 ~ 70%.The calcining of copper content 0.30 ~ 0.45% leaches under the condition of sulfuric acid concentration 50 ~ 60g/L, liquid-solid ratio 1.5:1, copper content in leachate=0.35% × 65% × 10/1.5=1.52g/L.Keep the solution circulated of acidity 50 ~ 60g/L to leach 6 times, copper content in leachate can be made to be elevated to 0.35% × 65% × 10/1.5 × 6=9.1g/L.Open a way out the leach liquor of a certain amount of sulfuric acid concentration 50 ~ 60g/L, copper concentration 9.1g/L, dilute 10 times, acidity and the copper concentration of solution are reduced to 5 ~ 6g/L and 0.91g/L respectively, and then carry out copper extraction, extraction of copper can bring up to more than 95%.。

Above-described embodiment, the just one of the present invention's more preferably embodiment, the usual change that those skilled in the art carries out within the scope of technical solution of the present invention and replacing all should be included in protection scope of the present invention.

Claims (5)

1. improve the dilution extraction process of copper recovery, it is characterized in that: in copper-containing solution two-stage countercurrent extracting system, the raffinate of one-level extraction after suitable proportion dilution, then carries out second stage extraction.

2. the dilution extraction process of raising copper recovery according to claim 1, is characterized in that: one-level raffinate can utilize new water or backwater as thinner.

3. according to the dilution extraction process of claim 1 and raising copper recovery according to claim 2, it is characterized in that: the add-on of new water or backwater is 30% ~ 100% of one-level raffinate liquid measure.

4. the dilution extraction process of raising copper recovery according to claim 1, it is characterized in that: the raffinate of one-level extraction is after suitable proportion dilution, when carrying out secondary extraction again, the mixing section of extraction tank, clarifying chamber's size do not need to change, and the flow of organic phase does not need to increase.

5. the dilution extraction process of raising copper recovery according to claim 1, it is characterized in that: this technique also can be applied to copper-contained material high acidic oils liquid extracting copper, cupric high acidic oils liquid circulating leaching, the leach liquor of regular part high-copper peracid of opening a way out, carry out the rear extracting copper of suitably dilution, reach the effect that high acidic oils improves copper leaching rate, low acid extraction improves extraction of copper.