Collaborative copper leaching process for soot of copper smelting converter

Abstract

The invention relates to a copper smelting converter soot synergistic copper leaching process, which belongs to the technical field of metallurgy, and comprises the following steps: S1, inoculating a specific culture medium with a compound strain according to a volume ratio of 1: (12-20), adding a converter soot sample with the weight being 2-4% of that of the specific culture medium and the particle size being 0.06-0.07 mm into the specific culture medium, then adding 10-90 mg / L of a surfactant, and uniformly stirring; and the pH is stabilized to 2-2.5 by adopting sulfuric acid with the concentration of 6-7mol / L. According to the method, a copper leaching strain is prepared by compounding bismuthophile and sulphide ore bacteria which are mutually synergistic, and is subjected to induced culture by adopting copper smelting soot, so that bismuth sulfate which is difficult to leach from the soot by using a conventional chemical method is dissolved into free-state high-activity bismuth ions, and the oxidation potential of a Fe < 3 + > / Fe < 2 + > galvanic couple in a soot leaching solution is improved to form a primary battery; the chemical reaction rate is increased, a vulcanization film on the surface of soot is eliminated, and the copper leaching rate is increased; meanwhile, the added surfactant improves the wettability of the surface of the cigarette ash, the contact environment of the leachate and the cigarette ash and the permeability of the surface of the cigarette ash, and further improves the leaching rate of the cigarette ash.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a copper smelting converter ash coordinated copper leaching process. Background Art

[0002] The development of the copper smelting industry has produced a large amount of smelting ash, which contains not only a large amount of valuable metals (including copper, zinc, cadmium, etc.), but also many harmful elements (including arsenic, lead, etc.), causing environmental pollution and waste of resources. Common treatment methods are mainly divided into two categories: pyrometallurgy and hydrometallurgy;

[0003] Fire smelting is to add additives, adhesives and other slag to make agglomerates and return them to the smelting system for re-smelting. The patent (CN110042255B) "A method for separating and recovering valuable metals in copper smelting ash by multi-stage controlled atmosphere roasting" uses a process of adding adhesives and then roasting copper ash at five different temperatures to recover the metals, which has a certain effect. However, there are problems such as high labor intensity, poor operating environment and low metal recovery rate.

[0004] In recent years, the wet treatment of copper ash has developed rapidly due to its great potential in solving environmental and cost problems, such as water leaching, acid leaching, chloride salt leaching, alkali leaching, etc. At present, most smelting enterprises adopt acid leaching for ash slag, but the leaching effect is not good, especially for converter ash, the copper leaching rate is only between 35% and 45%, and the proportion of copper sulfide in converter ash is as high as 70%. After a small amount of copper ions on the surface of copper sulfide are released and dissolved, the remaining copper and elemental sulfur form a dense barrier layer, that is, the copper in copper sulfide is wrapped by elemental sulfur and is difficult to leach, resulting in a low copper leaching rate of converter ash;

[0005] The invention patent (CN108034830B) "A method for comprehensive recovery of valuable metals in copper smelting smoke" adopts the method of magnetic separation pretreatment + acid leaching of different concentrations, which has achieved certain results, but there is a problem of low metal recovery rate. The invention patent (CN105567983B) "A process for treating smoke ash in copper smelting process" adopts the method of acid leaching + alkali leaching, and then neutralization and oxidation. Although the leaching rate is greatly improved, there is a problem of high cost;

[0006] Therefore, it is very necessary to seek a low-cost and high-efficiency co-leaching method for copper smelting ash. Summary of the invention

[0007] The purpose of the present invention is to provide a copper smelting converter ash coordinated copper leaching process in order to solve the above problems.

[0008] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0009] The present invention provides a copper smelting converter ash coordinated copper leaching process, comprising the following steps:

[0010] Step S1, inoculating the composite bacteria into a specific culture medium at a volume ratio of 1:12-20, adding a converter soot sample of 2%-4% by weight and a particle size of 0.06mm-0.07mm to the specific culture medium, then adding 10mg / L-90mg / L of a surfactant, and using sulfuric acid with a concentration of 6-7mol / L to stabilize the pH to 2-2.5;

[0011] Step S2, placing the above-mentioned leachate in an air bath constant temperature oscillator for 25 days to 30 days at 35° C. to 40° C. and 150 r / min to 300 r / min, and then centrifuging to remove the precipitated material, and then taking the supernatant to detect the copper ion content.

[0012] As a further optimization scheme of the present invention, the composite bacteria: Bismuthophilus and Thiobacillus ferroferrogenus are composited in a dosage ratio of 1:1-1.5.

[0013] As a further optimization scheme of the present invention, the surfactant in step S1 is sodium dodecyl sulfate.

[0014] As a further optimization scheme of the present invention, the specific composition of the specific culture medium used in step S2 is: FeSO4·7H2O 44.5g / L, (NH4)2SO4 3.0g / L, calcium salt supplement 0.01g / L, K2HPO4 3.0g / L, MgSO4·7H2O 3.0g / L, KCl 0.1g / L.

[0015] The beneficial effects of the present invention are as follows: a copper leaching strain prepared by compounding mutually synergistic bismuthophilic bacteria and sulfide ore bacteria is used, and copper smelting ash is used to induce and culture the strain, so that bismuth sulfate in the ash that is difficult to be leached by conventional chemical methods is dissolved into free highly active bismuth ions, thereby increasing the oxidation potential of the Fe3+ / Fe2+ couple in the ash leaching solution to form a primary battery, accelerating the chemical reaction rate, eliminating the sulfide film on the ash surface, and increasing the copper leaching rate; at the same time, the added surfactant improves the wettability of the ash surface, the contact environment between the leaching solution and the ash, and the permeability of the ash surface, further increasing the leaching rate of the ash;

[0016] Using surfactants, sodium dodecyl sulfate has the advantages of stable performance, low price, and no pollution. When the dosage is less than 90 mg / L, it has no inhibitory effect on the growth and oxidation activity of bismuthophilic and ferrosulfur bacteria, and has broad application prospects in the field of bioleaching. DETAILED DESCRIPTION

[0017] The present application is described in further detail below. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0018] 1. Materials

[0019] Unless otherwise specified, the methods used in the present invention are conventional methods known to those skilled in the art, and the reagents and other materials used are commercially available products unless otherwise specified.

[0020] 2. Embodiment

[0021] Example 1

[0022] The composite bacteria (bismuthophilus and ferrothiobacillus) were inoculated into a specific culture medium (FeSO4·7H2O 44.5g / L, (NH4)2SO4 3.0g / L, calcium salt supplement 0.01g / L, K2HPO4 3.0g / L, MgSO4·7H2O 3.0g / L, KCl 0.1g / L) at a volume ratio of 1:12, and a converter soot sample with a weight of 2% and a particle size of 0.06mm was added to the specific culture medium, and then 90mg / L of a surfactant (sodium dodecyl sulfate) was added, and sulfuric acid with a concentration of 6mol / L was used to stabilize the pH to 2;

[0023] The leaching solution was placed in an air bath constant temperature oscillator and oscillated for 30 days at 35°C and 200 r / min. After centrifugation to remove the precipitated material, the supernatant was taken to detect the copper ion content.

[0024] Typical converter ash composition is shown in Table 1 [Converter ash composition (%)]

[0025] With Zn CD Ace Bi Pb 5.3 9.02 4.69 9.3 4.85 28.5

[0026] Experimental steps: Take the bacterial culture medium and place it in a 250mL conical flask, weigh 50g of the ore sample and put it in the conical flask, adjust the pH of the slurry to 2, then inoculate a certain amount of active composite bacteria, then add 90mg / L surfactant, control the shaker temperature to 35℃, set the speed to 200rpm, and leaching for a total of 30 days.

[0027] Chemical composition of converter ash leaching slag (%)

[0028] With Zn CD Ace Bi Pb 1.14 0.28 0.73 7.45 3.85 29.26

[0029] The analysis results are as follows:

[0030] Through the chemical composition analysis of converter ash leaching slag, the leaching rate of copper is 91.84%, the leaching rate of zinc is 99.22%, the leaching rate of cadmium is 93.96%, and the leaching rate of arsenic is 66.21%.

[0031] Example 2

[0032] The composite bacteria (bismuthophilus and ferrothiobacillus) were inoculated into a specific culture medium (FeSO4·7H2O 44.5g / L, (NH4)2SO4 3.0g / L, calcium salt supplement 0.01g / L, K2HPO4 3.0g / L, MgSO4·7H2O 3.0g / L, KCl 0.1g / L) at a volume ratio of 1:20, and a converter soot sample with a weight of 4% and a particle size of 0.07mm was added to the specific culture medium, and then 60mg / L of a surfactant (sodium dodecyl sulfate) was added, and sulfuric acid with a concentration of 7mol / L was used to stabilize the pH to 2.5;

[0033] The above-mentioned leaching solution was placed in an air bath constant temperature oscillator and oscillated for 30 days at 40°C and 250 r / min. After centrifugation to remove the precipitated material, the supernatant was taken to detect the copper ion content.

[0034] Typical converter ash composition is shown in Table 2 [Converter ash composition (%)]

[0035] With Zn CD Ace 5.3 9.02 4.69 9.3

[0036] Experimental steps: Take the bacterial culture medium and place it in a 250mL conical flask, weigh 80g of the ore sample and place it in the conical flask, adjust the pH of the slurry to 2.5, then inoculate a certain amount of active composite bacteria, and then add 60mg / L surfactant. Control the shaker temperature to 40℃, set the speed to 250rpm, and leaching for a total of 30 days.

[0037] Chemical composition of converter ash leaching slag (%)

[0038] With Zn CD Ace 1.148 0.2 0.68 7.81

[0039] The analysis results are as follows:

[0040] Through the chemical composition analysis of converter ash leaching slag, the leaching rate of copper is 87.75%, the leaching rate of zinc is 98.87%, the leaching rate of cadmium is 92.6%, and the leaching rate of arsenic is 57.15%.

[0041] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A copper smelting ash coordinated copper leaching process, characterized in that: The following steps are involved: Step S1, inoculating the composite bacteria into a specific culture medium at a volume ratio of 1:12-20, adding a converter soot sample of 2%-4% by weight and a particle size of 0.06mm-0.07mm to the specific culture medium, then adding 10mg / L-90mg / L of a surfactant, and using sulfuric acid with a concentration of 6-7mol / L to stabilize the pH to 2-2.5; Step S2, placing the above-mentioned leachate in an air bath constant temperature oscillator for 25 days to 30 days at 35° C. to 40° C. and 150 r / min to 300 r / min, and then centrifuging to remove the precipitated material, and then taking the supernatant for detection.

2. The copper smelting ash coordinated copper leaching process according to claim 1, characterized in that: The composite bacteria: bismuthophilus and thiobacillus ferroferrogenus are composited in a dosage ratio of 1:1-1.

5.

3. The copper smelting ash coordinated copper leaching process according to claim 1, characterized in that: The surfactant in step S1 is sodium dodecyl sulfate.

4. The copper smelting ash coordinated copper leaching process according to claim 1, characterized in that: The specific composition of the specific culture medium used in step S1 is: FeSO4·7H2O 44.5g / L, (NH4)2SO4 3.0g / L, calcium salt supplement 0.01g / L, K2HPO4 3.0g / L, MgSO4·7H2O3.0g / L, KCl 0.1g / L.