JP2019052365A - Copper ore evaluating method and copper smelting method - Google Patents

Abstract

To reduce the discrepancy between an estimated amount of exudation of copper and an actual amount of exudation thereof.SOLUTION: A copper ore evaluating method includes: a first step in which copper is exuded from copper ore with sulfuric acid solution, to measure an amount of exudation of copper A; and a second step B in which copper is exuded from copper ore with solution containing iron (III) ions, to measure an amount of exudation of copper B. The first to second steps may be conducted in an arbitrary order.SELECTED DRAWING: None

Description

  The present invention relates to a copper ore evaluation method and a copper smelting method. More specifically, the present invention relates to a method for predicting the amount of copper leaching from copper ore. Furthermore, the present invention relates to a copper smelting method to which the prediction method is applied.

  One method for recovering copper from copper ore is the L-SX-EW method. In the L-SX-EW method, copper ore is leached with sulfuric acid or the like (L, Leaching), and copper ions are selectively recovered and concentrated from the copper leaching solution by solvent extraction (SX, Solvent Extraction). To produce electrolytic copper by electrowinning (EW).

  Copper ore can be classified into copper oxide ore, secondary copper sulfide ore, primary copper sulfide ore and the like. Copper oxide ore is easy to leach under the action of acid. Secondary copper sulfide ores can be leached by ferric leaching or the like.

  A column leaching test is a method generally used as a basic test for optimizing the leaching operation. The advantage of this method is that it is possible to obtain a result that matches well with the result of copper leaching at the actual operation level. On the other hand, the disadvantage of this method is that it takes too much time to obtain a result (eg several months).

In view of the above-mentioned drawbacks, a developed method is sequential analysis. Regarding this sequential analysis, for example, JP2013-189687A discloses the following procedure.
(1) Add sulfuric acid to a sample pulverized to a constant particle size and stir for a certain period of time. Quantify the eluted copper.
(2) A sodium cyanide solution is added to the solid portion obtained by solid-liquid separation of the sample of (1), and the mixture is stirred for a certain time. Quantify the eluted copper.
(3) Nitric acid and perchloric acid are added to the solid portion obtained by solid-liquid separation of the sample of (2), and after drying on a hot plate, hydrochloric acid and distilled water are added to dissolve the solid. Quantify the eluted copper.

  In the sequential analysis, the leaching amount determined in the above (1) is regarded as the leaching amount corresponding to copper oxide. Further, the leaching amount determined in the above (2) is regarded as the leaching amount corresponding to the secondary copper sulfide ore. Furthermore, the leaching amount determined in the above (3) is regarded as the leaching amount corresponding to the primary copper sulfide ore.

  In the sequential analysis, each of the steps (1) to (3) described above only takes about one hour, and therefore the entire process is completed in a few hours. In this respect, the sequential analysis is superior to the 1 m column test.

JP 2013-189687 A

  Therefore, it is useful that the amount of leaching of copper can be estimated by performing a sequential analysis that can be performed more easily before performing a time-consuming test such as a column test (for example, by a simple method, If it can be predicted in advance that the amount of leaching of copper is low, it can be determined that the column test is not performed, thereby saving time spent in the column test). Although there are such advantages, the above-described sequential analysis has a problem in the accuracy of the estimation of the leaching amount. For example, the leaching amount of secondary copper sulfide ore estimated from the results of sequential analysis may be significantly different from the leaching amount of secondary copper sulfide ore in the column test.

  In view of the above points, an object of the present invention is to provide a method for estimating the results of a 1 m column test, which is more accurate than sequential analysis.

  As a result of intensive studies by the present inventors, the following findings have been found. Conventionally, in sequential analysis, copper was leached using sodium cyanide in order to estimate the leaching amount corresponding to the secondary copper sulfide ore.

  Therefore, the inventor made the following changes. That is, in order to estimate the leaching amount corresponding to the secondary copper sulfide ore, copper was leached using a solution containing iron (III) ions instead of sodium cyanide. By this modification, it was found that the leaching amount corresponding to the secondary copper sulfide ore could be estimated with higher accuracy than the conventional sequential analysis.

  Based on the above findings, the present invention includes the following inventions in one aspect.

(Invention 1)
A method for evaluating copper ore, the method comprising:
A first step of leaching copper from a copper ore with a sulfuric acid solution and measuring a leached copper amount A; and a step of leaching copper from a copper ore with a solution containing iron (III) ions and measuring a leached copper amount B 2 steps;
Here, the first and second steps may be performed in an arbitrary order.
(Invention 2)
The method of the invention 1, further comprising a third step of measuring the total copper amount C contained in the copper ore.
(Invention 3)
The method of invention 2, wherein the first to third steps are carried out at least partially in parallel.
(Invention 4)
The method of invention 3, further comprising the step of estimating the leaching amount according to the following relationship:
Estimate the leaching rate a based on the values of the leached copper amount A and the total copper amount C; and the leaching rate b based on the difference between the leached copper amount B and the leached copper amount A and the value of the total copper amount C. Estimate.
(Invention 5)
The method of the invention 2, comprising:
The second step is performed on the residue obtained in the first step.
The method.
(Invention 6)
The method of invention 5, further comprising the step of predicting the leaching amount according to the following relationship:
Estimate the leaching rate a based on the values of the leached copper amount A and the total copper amount C; and estimate the leaching rate b based on the values of the leached copper amount B and the total copper amount C.
(Invention 7)
A method for producing electrolytic copper, comprising:
The process of evaluating the copper ore according to the method of any one of inventions 1-6:
Process of leaching copper from copper ore:
The process of refining electrolytic copper from copper leachate.

In one aspect, the method of the present invention includes the following steps:
A second step of leaching copper from a copper ore with a solution containing iron (III) ions and measuring the amount of leached copper B.
Thereby, an estimated value closer to the leaching amount in the column test can be obtained. And the suitable leaching method which should be employ | adopted can be determined.

The result of the leaching amount of the secondary copper sulfide ore in an Example is represented. The result of the leaching amount of the secondary copper sulfide ore in an Example is represented.

  Hereinafter, specific embodiments for carrying out the present invention will be described. The following description is intended to facilitate an understanding of the present invention. That is, it is not intended to limit the scope of the present invention.

1. Types of copper ores The copper ores described herein may be crude ores. The crude ore may be in a state where various minerals (eg, arsenite, chalcopyrite, chalcocite, etc.) are mixed. Alternatively, the copper ore described in the present specification may be composed of one kind of mineral (a simple mineral).

  Moreover, the copper mineral described in this specification can be classified from various viewpoints. Although it is not limited, for example, copper oxide, primary copper sulfide ore, secondary copper sulfide ore and the like can be mentioned from the viewpoint of characteristics relating to leaching.

Copper oxide ore can include, by way of example:
Atacamite;
Azure;
Malachite;
Tenorite;
Chrysocolla;
Cuprite;
Native Copper

  Copper oxide ore has the property of being easily dissolved in sulfuric acid.

  Secondary copper sulfide ore can include, by way of example: Chalcocite, Coverite. Secondary copper sulfide ore has the property of being easily dissolved in a sodium cyanide solution. Moreover, secondary copper sulfide ore has the property of being easily dissolved in a solution containing iron (III) ions.

  Primary copper sulfide ore can include, by way of example: Bornite, Chalcopyrite. Primary copper sulfide ore is hardly dissolved in the above-described solution containing sulfuric acid, sodium cyanide solution, and iron (III) ions. Instead, primary copper sulfide ore has the property of being easily dissolved in a solution containing nitric acid and perchloric acid. Further, primary copper sulfide ore has a property of being easily dissolved in a solution containing iron (III) ions and iodide ions.

2. In one embodiment, the present invention includes a method for predicting the amount of copper leached from copper ore (eg, crude ore and / or elemental mineral). The method can include at least the following steps:
A first step of leaching copper from a copper ore sample with a sulfuric acid solution and measuring the amount A of leached copper;
A second step of leaching copper from a copper ore sample with a solution containing iron (III) ions and measuring the amount B of leached copper.

  Note that the solution containing iron (III) ions used in the second step may not substantially contain iodide ions. “Substantially free of iodide ions” may mean that the concentration of iodide ions may be 0 g / L, or that it may be included to a level that does not substantially contribute to the leaching reaction. (Example: 0 to 0.1 g / L, more preferably 0 to 0.01 g / L, still more preferably 0 to 0.001 g / L).

(1) Estimation of leaching amount corresponding to copper oxide The first step is mainly intended to estimate a leaching amount corresponding to copper oxide. As described above, copper oxide has a property of being easily dissolved in sulfuric acid. Therefore, it is possible to estimate the amount of leaching related to copper oxide.

The leaching conditions are not particularly limited but may be as follows:
Temperature: 20 to 40 ° C. (preferably 20 to 30 ° C.)
Ingredient: sulfuric acid (1-10% v / v, preferably 4-6% v / v)
Time: 0.5-2h (preferably 0.8h-1.5h)
Shaking speed: 100 rpm to 200 rpm
Ore amount: 10-70 g / L (in the case of crude ore), 0.5-1.0 g / L (in the case of simple minerals)
Mineral particle size: 50-150 μm

In addition, about a solution component, you may add another substance.

(2) Estimation of leaching amount corresponding to secondary copper sulfide ore The purpose of the second step is to estimate a leaching amount mainly corresponding to secondary copper sulfide ore. As described above, secondary copper sulfide ore has the property of being easily dissolved in a solution containing trivalent Fe ions.

For example, it is considered that the reaction of Chalcosite, which is one type of secondary copper sulfide ore, proceeds according to the following reaction formula.
Cu ₂ S + 4Fe ³⁺ → 2Cu ²⁺ + 4Fe ²⁺ + S

  Moreover, the solution containing trivalent Fe ions has the property of dissolving not only secondary copper sulfide ore but also the above-described copper oxide. Therefore, the leaching amount of copper by the solution containing trivalent Fe ions can be estimated as a combined amount of both copper oxide and secondary copper sulfide ores. Therefore, by subtracting the leaching amount estimated in the first step from the leaching amount estimated in the second step, the leaching amount corresponding to the secondary copper sulfide ore can be estimated. Alternatively, after leaching copper oxide in the first step, the residue may be subjected to the second step. In this case, the leaching amount estimated in the second step can be estimated as the leaching amount corresponding to the secondary copper sulfide ore.

  Further, compared with the conventional method (for example, compared with the sequential analysis), the analysis method of the present invention can obtain an estimated amount that well matches the leaching result of the column test. Although the following description is not intended to limit the present invention, in the case of a sample containing Jarosite or carbonate, the leaching amount in the 1 m column test is small compared to the conventional sequential analysis, and the 1 m column test The results of conventional sequential analysis may differ.

The leaching conditions are not particularly limited but may be as follows:
Temperature: 20 to 65 ° C. (preferably 45 to 55 ° C.)
pH: 1.6 to 2.0 (preferably 1.7 to 1.9, adjustment may not be performed)
Ingredients: Fe ³⁺ (1-10 g / L, preferably 4-6 g / L)
Time: 0.5h to 200h (preferably 0.5 to 2h, or 20 to 30h, or 150 to 180h)
Shaking speed: 100 rpm to 200 rpm
Ore amount: 10-70 g / L (in the case of crude ore), 0.5-1.0 g / L (in the case of simple minerals)
Mineral particle size: 50-150 μm
In addition, about a solution component, you may add another substance.

Note that the source of trivalent Fe ions, it is possible to use a compound of the ₂ O such as iron sulfate n-hydrate _{Fe 2 (SO 4) 3 ·} nH. Alternatively, a solution of divalent Fe ions (eg, ferrous iron sulfide) may be supplied and then converted to trivalent Fe ions by iron-oxidizing bacteria or the like.

(3) Total amount of copper contained in copper ore In one embodiment, the method of the present invention may include a third step of measuring the total amount of copper contained in copper ore. The total amount of copper contained in the copper ore can be measured by a method of alkali melting / wet analysis (ICP-OES) after filtering the leached solution. The total amount of copper can be obtained by directly measuring the amount of copper contained in the crude ore. Alternatively, the total amount of copper can be obtained by summing the amounts of copper contained in each of the liquid after leaching and the leaching residue. And it becomes possible to calculate a leaching rate by calculating the total amount of copper. Therefore, the leaching amount in the column test can be estimated based on the estimated amount obtained from the sample.

  The first and second steps described above can be performed in any order. Alternatively, the first and second steps can be performed at least partially in parallel. Furthermore, the process of measuring the total amount of copper contained in the copper ore can be performed in any order, and the first to third processes can be performed at least partially in parallel.

  When carrying out in parallel, the sample may be divided into two and each may be subjected to the first and second steps. Alternatively, the sample may be divided into three and each may be subjected to the first to third steps. And time reduction can be aimed at by implementing in parallel.

  In the case of carrying out sequentially, the sample is first subjected to the first step, and after the first step, the residue is taken out by solid-liquid separation. Next, the residue is subjected to a second step, and then the residue is taken out by solid-liquid separation. With the sequential method, even when the amount of the sample is small, the evaluation can be performed without reducing the accuracy (for example, with the above-described method performed in parallel, the sample has to be divided, so that one The amount of sample to be analyzed is reduced). In addition, the sequential method can reduce the problem of sample variation (for example, if the method is performed in parallel as described above, the possibility of occurrence of bias cannot be excluded when the sample is divided).

3. Leaching method in column test After performing the above analysis using a sample of copper ore, copper can be leached in the column test.

(1) Copper oxide ore and secondary copper sulfide ore For example, when it is determined that the ratio of copper oxide ore is large in the copper ore through the above analysis results, a leaching method suitable for copper oxide ore can be adopted. Moreover, when it is judged from the above analysis results that the ratio of secondary copper sulfide ore is large in the copper ore, a leaching method suitable for secondary copper sulfide ore can be adopted. The leaching method suitable for the copper oxide ore and the secondary copper sulfide ore is not limited, and examples thereof include dump leaching and heap leaching.

  In adopting the leaching method described above, the estimated amount obtained in the first to second steps (more preferably, the first to third steps) described above can be referred to.

  For example, when the first to second steps (more preferably, the first to third steps) are performed at least partially in parallel, the leaching rate estimated based on the leaching amount obtained in the second step. Can be helpful. In one example, when the leaching rate is 70% or more, it may be determined to employ a leaching method suitable for copper oxide and secondary copper sulfide ore.

  As another example, when the first and second steps are performed sequentially, the leaching rate estimated based on the leaching amounts obtained in the first step and the second step can be referred to. In one example, when the leaching rate is 70% or more, it may be determined to employ a leaching method suitable for copper oxide and secondary copper sulfide ore.

4). Selection method of copper ore and selection method of leaching means The analysis method can be applied in various forms. For example, when there are multiple candidate copper ores, select a copper ore suitable for a specific leaching method (eg, iodine method, dump leaching, heap leaching, etc.) based on the results of the above analysis method. Can do. In another example, when selecting an optimum leaching method for the collected copper ore, the leaching method can be selected based on the result of the analysis method. In another example, whether or not the collected copper ore is suitable for a specific leaching method (eg, iodine method, dump leaching, heap leaching, etc.) can be determined based on the results of the above analytical method. .

5. Production of electrolytic copper In one embodiment, the present invention can include a method for producing electrolytic copper. The method may include performing the above-described prediction method (the method described in “2. Method of predicting leaching amount”). In addition, the method for producing electrolytic copper can include a step of actually leaching copper from the copper ore after the leaching amount is predicted. The step of leaching copper can include performing the above-described leaching method (the method described in the section of “3. Leaching Method in Column Test”). Through the above process, a copper leaching solution can be obtained. From the obtained leachate, copper ions can be selectively collected and concentrated by solvent extraction (SX, Solvent Extraction). Then, electrolytic copper can be produced from the copper solution by electrowinning (EW).

  The following examples are intended to facilitate a further understanding of the invention. That is, it is not intended to limit the scope of the present invention.

6). Analytical method Sequential analysis (as a comparative example), 1m column test (as a reference example), and iron (III) ions are used to measure the ratio of copper oxide ore, primary copper sulfide ore, and secondary copper sulfide ore in copper ore. Analysis method (as an example).

6-1. Sequential analysis Sequential analysis was performed according to the following procedure.
(1) Copper oxide ore: Sulfuric acid was added to a sample ground to a constant particle size and stirred for a certain period of time. Quantify the eluted copper (CuAS).
(2) Secondary copper sulfide ore: A sodium cyanide solution was added to the solid portion obtained by solid-liquid separation in copper oxide ore analysis, and the mixture was stirred for a certain time. Quantify the eluted copper (CuCN).
(3) Primary copper sulfide ore: Nitric acid and perchloric acid are added to the solid portion obtained by solid-liquid separation of secondary copper sulfide ore. After solidifying on a hot plate, hydrochloric acid and distilled water are added to dissolve the solid. Quantify the eluted copper (CuIns).

6-2.1m Column Test The 1m column test is a test method that can obtain results close to the leaching results obtained at the actual operation scale. However, there is a drawback that it takes several months to obtain the result.

In order to make the sample representative of the whole, the sample was first reduced (sample reduction). Thereafter, classification was performed using a 4.75 mm sieve. The sample that passed through the sieve and the sample that remained on the sieve were mixed, and a total of 12 kg of the sample was packed into a column having a height of 1 m and a distribution area of 7.85 × 10 ⁻³ m ² . Next, a leachate was prepared. More specifically, a leachate having a pH of 1.6 and an iron (III) concentration of 5 g / L (Fe source is iron sulfate n hydrate) was prepared. The leachate was fed from the top of the column at a rate of 1 L / day. This was done for a maximum of 120 days. And the quantity of Cu contained in the solution which passed the column was measured.

6-3. Analytical Method Using Iron (III) Ion An analytical method using iron (III) ion was carried out by the following procedure.
The copper ore sample was divided into at least three. The analysis of the total amount of copper (CuT) contained in the first copper ore sample was commissioned to an analysis organization. The second copper ore sample was leached under the following conditions, and the amount of Cu leaching was measured (CuAS).
Temperature: 25 ° C
Ingredient: sulfuric acid (5% v / v)
Time: 1h
Shaking speed: 180rpm
Ore amount: 40 g / L
Mineral particle size: −100 μm (ie, the size passing through a sieve having a mesh size of 100 μm, and so on)

The third copper ore sample was leached under the following conditions. And the amount of Cu leaching was measured (CuFe).
Temperature: 50 ° C
Ingredients: Fe ³⁺ (5 g / L)
Time: 24h
Shaking speed: 120rpm
Ore amount: 40 g / L (crude ore), 0.8 g / L (simple mineral)
Mineral particle size: -100 μm

  The copper concentration and iron concentration in the leachate were measured with an ICP emission spectroscopic analyzer (ICP-AES).

  The amount of copper leaching in each sample was measured by the above method. Thereafter, the CuT yield was calculated by dividing the measured value by the total amount of copper (CuT) in the sample.

7). Difference in leaching amount corresponding to secondary copper sulfide ore and analysis method Four types (samples A to D) of coarse ore were adopted as samples from different mines.

The three types of analysis methods described above were performed, and the amount of leaching corresponding to secondary copper sulfide ore was measured. The results are shown in FIG. In the graph of FIG. 1, for the sequential analysis, the time point when 80% of the CuAS is leached is plotted as the time point when the amount of leachate corresponds to 0.5 m ³ / t. In the analysis method using iron (III) ions, the time when 80% of the above-mentioned CuFe was leached was plotted as the time when the amount of leachate was equivalent to 0.5 m ³ / t.
In any crude ore (samples A, B, D), the results of the analysis by the 1 m column test and the analysis method using iron (III) ions were similar to the results of the sequential analysis. On the other hand, in the sample (sample C) containing Jarosite / carbonate that had a discrepancy between the result of the 1 m column test and the result of the sequential analysis, the result of the analysis method using iron (III) ions was more than the result of the sequential analysis. The result was close to the result of the 1 m column test.

  In this specification, the description “or” or “or” includes a case where only one of the options is satisfied or a case where all the options are satisfied. For example, in the case of the description “A or B” or “A or B”, it includes both the case where A is satisfied and B is not satisfied, the case where B is satisfied and A is not satisfied, and the case where A is satisfied and B is satisfied I intend to.

  The specific embodiments of the present invention have been described above. The said embodiment is only a specific example of this invention, and this invention is not limited to the said embodiment. For example, the technical features disclosed in one of the above embodiments can be provided in other embodiments. Moreover, about a specific method, it is also possible to replace a part process with the order of another process, and you may add an additional process between two specific processes. The scope of the invention is defined by the claims.

Claims (7)

A method for evaluating copper ore, the method comprising:
A first step of leaching copper from a copper ore with a sulfuric acid solution and measuring a leached copper amount A; and a step of leaching copper from a copper ore with a solution containing iron (III) ions and measuring a leached copper amount B 2 steps;
Here, the first and second steps may be performed in an arbitrary order.   The method according to claim 1, further comprising a third step of measuring a total copper amount C contained in the copper ore.   3. The method of claim 2, wherein the first to third steps are performed at least partially in parallel. 4. The method of claim 3, further comprising the step of estimating the leaching amount according to the following relationship:
Estimate the leaching rate a based on the values of the leached copper amount A and the total copper amount C; and the leaching rate b based on the difference between the leached copper amount B and the leached copper amount A and the value of the total copper amount C. Estimate. The method of claim 2, comprising:
The second step is performed on the residue obtained in the first step.
The method. 6. The method of claim 5, further comprising the step of predicting the amount of leaching according to the following relationship:
Estimate the leaching rate a based on the values of the leached copper amount A and the total copper amount C; and estimate the leaching rate b based on the values of the leached copper amount B and the total copper amount C. A method for producing electrolytic copper, comprising:
The step of evaluating copper ore according to the method of any one of claims 1-6:
Process of leaching copper from copper ore:
The process of refining electrolytic copper from copper leachate.