KR100557410B1 - Bioleaching refining method of copper, nickel and cobalt from Mn nodule-matte by T.ferrooxidans - Google Patents

Abstract

The present invention relates to a smelting method for leaching copper, nickel, cobalt, etc. in an ionic state using a microorganism, Thiobacillus ferrooxidans (hereinafter referred to as T.ferrooxidans ) , from a poorly soluble mat, an intermediate product of deep sea manganese nodules. Economical and environmentally friendly microorganism leaching of valuable metals by using microorganisms from ore or valuable metal intermediate products with high environmental pollution due to the generation of low-grade ore or tailings or large amount of sulfide gas during treatment To provide process technology.

The composition of the present invention provides a microbial leaching process technology, cultivation of microorganisms by appropriate medium, recovery of cultured microorganisms, leaching of valuable metals from the mat by the inorganic salt medium inoculated with microorganisms, leaching after a certain time leaching reaction And a method of separating the leach solution from the residue.

Microbial Leaching, Manganese Nodule Intermediates, Mat, Ferric Oxide, Valuable Metals, Substrates

Description

Bioleaching refining method of copper, nickel and cobalt from Mn nodule-matte by T.ferrooxidans}

The present invention relates to a method for smelting microorganisms of copper, nickel and cobalt by T. ferrooxidans from an intermediate product of manganese nodules.

Although there are many kinds of domestic resources, the size of the minerals and their low quality have limited demand for them, and the imports of high-quality raw materials and primary processing materials have continued to increase. In addition, there is no economic feasibility of existing treatment methods, and most domestic mines are closed and abandoned, and trade deficits are expanding. Therefore, in the short term, it is necessary to develop new technologies that can add value by economically treating domestic insoluble / low-grade mineral resources. In the long term, it is urgent to prepare environmentally-friendly treatments to recover valuable resources from waste ore, tailings or heavy metal-containing wastes in abandoned and abandoned mines, and to suppress and solve serious environmental pollution problems such as soil and groundwater contaminated with wastewater.

Microbial leaching is a process that changes the physical and chemical properties of metal ores by the direct and indirect reactor of microorganisms and leaches the metal into ionic state. Low-grade ore that is not suitable for treatment by conventional dry and wet processes due to low metal content. However, it is evaluated as an economical treatment method for recovering valuable metals from poorly soluble minerals in which small amounts of precious metals are dispersed. In addition, the energy consumption is small and SO ₂ gas is not emitted, so it does not cause environmental problems, has a small initial investment, a simple process / operation, and does not require high technical knowledge.

Most of the metal recovery processes using microorganisms are recovered by leaching the metal by oxidizing iron or sulfated bacteria under an aerobic atmosphere. Iron oxidizing bacteria in aerobic atmosphere are used to leach metals because of the fast leaching rate of metals and excellent viability compared to other bacteria. In addition, since the intermediate product of manganese nodules contains a large amount of sulfur, it is difficult to recover valuable metals by conventional physicochemical smelting methods.

In other words, strong acid and strong alkali are required when leaching mat by acid and alkali leaching method. However, this leaching method is very serious in environmental pollution, and when smelting by roasting method generates large amount of sulfide gas. It is causing.

Therefore, there is an urgent need to develop an eco-friendly smelting technology that leaches and recovers valuable metals without using strong acids and strong alkalis at room temperature under normal temperature and pressure from manganese nodules, which is a product of manganese nodules.

SUMMARY OF THE INVENTION An object of the present invention for solving the above problems is to provide a biological leaching method for leaching valuable metals into an aqueous solution from a mat, a manganese nodule intermediate containing valuable metals such as copper, nickel and cobalt. .

The construction and operation of the embodiment of the present invention for achieving the object as described above and solving the disadvantages of the existing smelting method in detail as follows.

The present invention particle sizes - as is of 100 mesh manganese nodules intermediates mats (see Table 1) the sample to leaching, the microorganism of the iron hwagyun T.ferrooxidans, a carbon source and nutrients 9K medium (see Table 2), experimental Apparatus is a microbial leaching method using a shaking incubator that can control the humidity and humidity.

Table 1. Chemical composition of mat as an intermediate for smelting manganese nodules

Component Ni Cu Co Fe S Contents (wt%) 39.3 24.8 3.9 11.1 20.9

Table 2. Compound Composition of 9K Medium (g of Components Constituting 1 L in Total)

9K medium (g / ℓ) (NH ₄ ) ₂ SO ₄ 3.0 K ₂ HPO ₄ 0.5 MgSO ₄ H ₂ O 0.5 KCl 0.1 Ca (NO ₃ ) ₂  0.01 FeSO ₄ 7H ₂ O 45.0 Solvent distilled water Remainder pH 2.0

Specific method of the present invention

Culturing the iron oxide bacteria used as a microbial strain in a constant temperature and humidity bath;

Separating and concentrating the cultured microbial strain in a centrifuge,

It is a microbial leaching method for recovering the leaching solution of the valuable metal eluted through the step of inoculating the microbial strain into a reaction tank mixed with an inorganic salt medium (9K) and the mat.

Incubating iron oxide bacteria used as a microbial strain in the constant temperature and humidity bath inoculated 1 weight part of iron oxide bacteria in 100 parts by weight of 9K medium solution in a constant temperature and humidity bath maintained constant at 30 ℃ (optimal activity temperature of the bacteria). Maintain 48 hours (the best time for the activity, after which time the bacteria enter the decline phase). If the iron oxidizing bacteria exceeds 1 part by weight, the survival rate is low due to the lack of nutrients of the bacteria, if less than 1 part by weight requires more than 48 hours to incubate.

In the step of separating and concentrating the cultured microbial strain in a centrifugal separator, 10 minutes at 9000 rpm, 5 minutes at 3000 rpm, 5 minutes at 2500 rpm, and 10 minutes at 9000 rpm based on 100 parts by weight of the culture medium mixed with 9K medium and bacteria. After centrifugation, the supernatant was removed to precipitate only the strain, and then the mixture was concentrated by mixing the strain with the inorganic salt solution prepared by removing FeSO ₄ · 7H ₂ O from the 9K solution of Table 2 in order to easily dilute it.

The reason for the speed and time limitation of the centrifugation step of the culture is that the best centrifugation results are obtained at each of the above values.

That is, the reason for centrifugation at 9000 rpm for 10 minutes is to precipitate all solids in the culture solution, and the reason for centrifugation at 3000 rpm for 5 minutes is to precipitate only heavy iron hydroxide (zarosite) without light strains from the precipitated solids. , 5 minutes centrifugation at 2500rpm is to precipitate only heavy iron hydroxide (zarosite) except light strain again, finally centrifugation at 9000rpm for 10 minutes after precipitation of the strain in the solution removed This is to remove the supernatant.

In addition, the inorganic salt solution (mineral salt) and strain prepared by removing FeSO ₄ · 7H ₂ O from the 9K solution of Table 2 is required for the subsequent step after mixing OD (Optical density) value 0.1 (good viability of the bacteria) Since it does not have to be adjusted to a specific mixing ratio, it can be made into a suitable solution.

Inoculating and leaching the microbial strain into the reaction tank mixed with the inorganic salt medium (9K) and the mat is mixed with 1 to 20 parts by weight to 100 parts of the inorganic salt medium solution in a high liquid ratio of the mat in the inorganic salt medium, and then the strain and The mixed solution of the inorganic salt solution was inoculated to an optical density (OD) value of 0.1 (good viability of bacteria) measured on a spectrophotometer, and then adjusted to 30 ° C. (good bacterial activity). After installation in the shake bath, the leaching reaction for 1 to 10 days while rotating to 180rpm (lower than 180rpm, less stirring effect, high solution overflow occurs).

In the leaching reaction, the initial pH of the inorganic salt medium is 1-4.

In addition, the concentration of Fe ²⁺ added as a substrate in the 9K medium in the leaching reaction proceeds by adding 0.1 to 1.2 parts by weight of FeSO _{4 ·} 7H ₂ O based on 100 parts by weight of 9K medium.

The reason for the addition of the substrate is that Fe ²⁺ added by iron oxidizing bacteria is oxidized to Fe ^3+, and the oxidized Fe ³⁺ serves as a powerful oxidant to elute valuable metals.

After a predetermined reaction time, the reactor was dismantled to separate solid and liquid by a pump filter, and the ion concentration of copper, nickel, and cobalt in the solution was analyzed by atomic absorption spectrophotometer to determine the leaching rate of valuable metals. Measured.

Hereinafter will be described a preferred embodiment according to the present invention.

Example 1

5 parts by weight of the mat was mixed with 100 parts of the inorganic salt medium solution, and the iron oxide bacteria were inoculated in accordance with the OD (Optical density) value of 0.1 (good viability of the bacteria) measured on a spectrophotometer, and then incubated at 30 ° C. After being installed in a shaker adjusted to the state of the best activity of the reaction, it is reacted for 1 day while rotating to 180rpm (lower than 180rpm, less stirring effect, higher solution occurs).

In the leaching reaction, the initial pH of the inorganic salt medium was set to 2, and the experiment was performed by adding the concentration of Fe ²⁺ added as a substrate to 0.5 parts by weight based on 100 parts by weight of 9K medium.

The reaction solution was performed at a reaction temperature of 30 ° C. while stirring at 180 rpm.

After completion of the reaction time, the reactor was dismantled and the solid and liquid separation was performed using a pump filter. The ion concentrations of copper, nickel, and cobalt in the solution were analyzed by atomic absorption spectrometer to measure the elution efficiency. As a result, as shown in Table 3, it can be seen that the metals are leached even in 24 hours.

Table 3. Leaching Rate of Valuable Metals by Microorganisms (Fe ²⁺ : 5g / ℓ, Solids Ratio: 5%, pH: 2)

Reaction time Leaching rate of metal (%) Copper nickel cobalt 1 day 15 8 3

Example 2

20 parts by weight of the mat is mixed with 100 parts of the inorganic salt medium solution, and the iron oxide bacteria are inoculated in accordance with the OD (Optical density) value of 0.1 (good viability of the bacteria) measured on a spectrophotometer, and then incubated at 30 ° C. After the reaction was installed in a shaker adjusted to the best state of the reaction, the reaction was performed for 10 days while rotating at 180 rpm (less than 180 rpm, the stirring effect is low, and the solution overflows). In the leaching reaction, the initial pH of the inorganic salt medium was 1 and the concentration of Fe ²⁺ added as an additional substrate was 0.5 parts by weight based on 100 parts by weight of 9K medium.

The reaction solution was performed at a reaction temperature of 30 ° C. while stirring at 180 rpm.

After completion of the reaction time, the reactor was dismantled and the solid and liquid separation was performed using a pump filter. The ion concentrations of copper, nickel, and cobalt in the solution were analyzed by atomic absorption spectrometer to measure the elution efficiency. As a result, as shown in Table 4, it can be seen that metals are leached by microorganisms even under a high liquid ratio of 20%.

Table 4. Leaching Rate of Valuable Metals by Microorganisms (Fe ²⁺ : 5g / ℓ, Solids Ratio: 20%, pH: 1)

Reaction time Leaching rate of metal (%) Copper nickel cobalt 10 days 17 30 5

Example 3

5 parts by weight of the mat was mixed with 100 parts of the inorganic salt medium solution, and inoculated to an optical density (OD) value of 0.1 (good bacterial viability) measured on a spectrophotometer, and then inoculated at 30 ° C. After being installed in the shaking tank adjusted to the best condition, the reaction is rotated for 180 days while rotating at 180 rpm (less than 180 rpm, the stirring effect is low, and the solution overflows). In the leaching reaction, the initial pH of the inorganic salt medium was 4, and the concentration of Fe ²⁺ added as the substrate was 0.5 parts by weight based on 100 parts by weight of 9K medium.

The reaction solution was performed at a reaction temperature of 30 ° C. while stirring at 180 rpm.

After completion of the reaction time, the reactor was dismantled and the solid and liquid separation was performed using a pump filter. The ion concentrations of copper, nickel, and cobalt in the solution were analyzed by atomic absorption spectrometer to measure the elution efficiency. As a result, as shown in Table 4, the leaching rate of nickel at the initial pH of the inorganic salt medium was about 56%, and copper and cobalt were 40% and 21%, respectively.

Table 5. Leaching Rate of Valuable Metals by Microorganisms (Fe ²⁺ : 5g / ℓ, Solids Ratio: 5%. PH: 4)

Reaction time Leaching rate of metal (%) Copper nickel cobalt 10 days 40 56 21

Example 4

1 part by weight of the mat is mixed with 100 parts by weight of the inorganic salt medium, and the iron oxide bacteria are inoculated in accordance with the OD (Optical density) value 0.1 (good viability of the bacteria) measured on a spectrophotometer, and then incubated at 30 ° C. After the reaction was installed in the shaking bath adjusted to the state of the best (), the reaction was rotated for 10 days while rotating to 180rpm (lower than 180rpm, less agitation effect, higher solution occurs). In the leaching reaction, the initial pH of the inorganic salt medium was 1, and the concentration of Fe ²⁺ added as a substrate was 0.5 parts by weight based on 100 parts by weight of 9K medium.

The reaction solution was performed at a reaction temperature of 30 ° C. while stirring at 180 rpm.

After completion of the reaction time, the reactor was dismantled and the solid and liquid separation was performed using a pump filter. The ion concentrations of copper, nickel, and cobalt in the solution were analyzed by atomic absorption spectrometer to measure the elution efficiency. As a result, as shown in Table 4, the leaching rate of nickel was about 42% when mixing 1 part by weight of the mat with 100 parts of the inorganic medium solution, and copper and cobalt were 78% and 13%, respectively.

Table 6. Leaching Rate of Valuable Metals by Microorganisms (Fe ²⁺ : 5g / ℓ, Solids Ratio: 1%, pH: 1)

Reaction time Leaching rate of metal (%) Copper nickel cobalt 10 days 78 42 13

Example 5

5 parts by weight of the mat was mixed with 100 parts of the inorganic salt medium solution, and the iron oxide bacteria were inoculated in accordance with the OD (Optical density) value of 0.1 (good viability of the bacteria) measured on a spectrophotometer, and then incubated at 30 ° C. After the reaction was installed in the shaking bath adjusted to the state of the best (), the reaction was rotated for 10 days while rotating to 180rpm (lower than 180rpm, less agitation effect, higher solution occurs). In the leaching reaction, the initial pH of the inorganic salt medium was 1, and the concentration of Fe ²⁺ added as the substrate was 1.2 parts by weight based on 100 parts by weight of 9K medium.

The reaction solution was performed at a reaction temperature of 30 ° C. while stirring at 180 rpm.

After completion of the reaction time, the reactor was dismantled and the solid and liquid separation was performed using a pump filter. The ion concentrations of copper, nickel, and cobalt in the solution were analyzed by atomic absorption spectrometer to measure the elution efficiency. As a result, as shown in Table 4, the leaching rate of nickel was about 42% when the concentration of Fe ²⁺ added as the substrate was added at 1.2 parts by weight based on 100 parts by weight of 9K medium, and copper and cobalt were 78% and 13%, respectively. .

Table 7. Leaching Rate of Valuable Metals by Microorganisms (Fe ²⁺ : 12g / ℓ, Solids Ratio: 5%, pH: 1)

Reaction time Leaching rate of metal (%) Copper nickel cobalt 10 days 78 42 13

Example 6

5 parts by weight of the mat was mixed with 100 parts of the inorganic salt medium solution, and the iron oxide bacteria were inoculated in accordance with the OD (Optical density) value of 0.1 (good viability of the bacteria) measured on a spectrophotometer, and then incubated at 30 ° C. After the reaction was installed in the shaking bath adjusted to the state of the best (), the reaction was rotated for 10 days while rotating to 180rpm (lower than 180rpm, less agitation effect, higher solution occurs). In the leaching reaction, the initial pH of the inorganic salt medium was 1, and the concentration of Fe ²⁺ added as the substrate was 0.1 parts by weight based on 100 parts by weight of 9K medium.

The reaction solution was performed at a reaction temperature of 30 ° C. while stirring at 180 rpm.

After completion of the reaction time, the reactor was dismantled and the solid and liquid separation was performed using a pump filter. The ion concentrations of copper, nickel, and cobalt in the solution were analyzed by atomic absorption spectrometer to measure the elution efficiency. As a result, as shown in Table 4, the leaching rate of nickel at about 0.1 parts by weight of Fe ²⁺ added as a substrate was about 38%, and copper and cobalt were 81% and 13%, respectively.

Table 8. Leaching Rate of Valuable Metals by Microorganisms (Fe ²⁺ : 1g / ℓ, Solids Ratio: 5%, pH: 1)

Reaction time Leaching rate of metal (%) Copper nickel cobalt 10 days 81 38 13

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

According to the present invention, it is possible to operate under room temperature and normal pressure from a poorly soluble mat containing valuable metals, and provides an environmentally friendly biological metal leaching process to recover valuable metals from sulphide, which has a lot of environmental pollution in the existing smelting process. It is a process. In addition, the present invention is a useful invention having the advantage of effectively smelting valuable metals from the eluate leached from the mat by a biological method using a physico-chemical smelting method is an invention that is expected to be used in industry.

Claims (5)

In the method of recovering the metal by leaching by inoculating the iron oxide bacteria in the culture medium and the mixture of minerals, Culturing the iron oxide bacterium incubated for 48 hours by inoculating 1 part by weight of the bacterium in an inorganic salt medium (9K) solution in a constant temperature and humidity bath maintained at 30 ° C; (NH ₄ ) ₂ SO ₄ , K ₂ HPO ₄ , MgSO ₄ · H ₂ O, KCl, Ca (NO ₃ ) ₂ , FeSO ₄ · 7H ₂ O and 9K medium and iron oxide bacteria Based on 100 parts by weight of the culture, centrifugation at 9000 rpm for 10 minutes to precipitate all solids in the culture, and then centrifugation at 3000 rpm for 5 minutes to precipitate only heavy iron hydroxide (zarosite) without light strains. And then centrifuging at 2500 rpm for 5 minutes to precipitate only heavy iron hydroxide (zarosite) without the light strain again, and finally to precipitate only the strain in the solution from which the precipitate was removed by centrifugation at 9000 rpm for 10 minutes. A separation step of removing the supernatant; The inorganic salt solution (mineral) composed of the precipitate mass separated and precipitated in the separation step and (NH ₄ ) ₂ SO ₄ , K ₂ HPO ₄ , MgSO ₄ · H ₂ O, KCl, Ca (NO ₃ ) _2, and solvent distilled water. salt) mixing and concentrating; separating and concentrating the microbial strain cultured in the culture consisting of a centrifuge; A separate concentrate the microbial strain culture solution was adjusted to an initial pH to 1-4, and then in the reaction tank _{(NH 4) 2 SO 4,} K 2 HPO 4, MgSO 4 · H 2 O, KCl, Ca (NO 3) 2, FeSO 4 OD measured on a spectrophotometer in a mixture containing 1-20 parts by weight of an intermediate salt of manganese nodule in 100 parts by weight of inorganic salt medium (9K) composed of 7H ₂ O and solvent distilled water. Optical density) was inoculated at a value of 0.1, and then placed in a shaker controlled at 30 ° C., followed by leaching for 1-10 days while rotating at 180 rpm. The leaching reaction of Fe ²⁺ was added as a substrate to 9K medium. The concentration is a leaching reaction proceeding by adding 0.1 to 1.2 parts by weight based on 100 parts by weight of FeSO _{4 ·} 7H ₂ O based on 9K medium; Manganese nodules characterized in that the leaching of cobalt under ions in the ion state from the mat From nickel, an intermediate product of , Cobalt microbial leaching smelting method. delete delete delete delete