1. A method for chemical analysis of copper phases in copper concentrates, characterized by comprising the steps of:

s1, separating water-soluble copper in the copper concentrate to be detected, and determining the content of the water-soluble copper by adopting an atomic absorption method;

s2, separating the copper oxide in the filter residue A obtained in the step S1, and determining the content of the copper oxide by adopting an atomic absorption method;

s3, separating the native copper in the filter residue B obtained in the step S2, and determining the content of the native copper by adopting an atomic absorption method;

s4, separating the copper sulfide in the filter residue C obtained in the step S3, and determining the content of the copper sulfide by adopting a titration method;

wherein the step of separating copper sulfide in the step of S4 includes:

firstly, heating and dissolving the filter residue C by using dilute nitric acid, then adding dilute sulfuric acid to continue heating and decomposing, then evaporating the solution to dryness, adding dilute sulfuric acid to heat and dissolve to obtain a mixture of copper and iron, then masking iron and determining the content of copper sulfide by using a titration method.

2. The method of chemical analysis of copper phases in copper concentrate according to claim 1, wherein the step of separating copper sulfide in step S4 comprises:

putting the filter residue in a beaker, wetting the filter residue with distilled water, adding dilute nitric acid, covering a watch glass, heating the beaker at 180 +/-5 ℃ for 10 minutes, adding dilute sulfuric acid, continuously heating to decompose a sample, after the violent reaction stops, cleaning the watch glass with a small amount of water, removing the watch glass, continuously heating at high temperature until dense white smoke is emitted, taking down the watch glass after the dense white smoke is completely dispersed, and cooling the watch glass; washing the bottle wall with distilled water, and then heating and steaming to be nearly dry; adding 0.5% dilute sulfuric acid, heating to dissolve soluble salt, adding distilled water, heating to slightly boil to dissolve, cooling to room temperature, and dissolving the generated copper salt completely.

3. The method for chemical analysis of copper phases in copper concentrates according to claim 1 or 2, characterized in that the method for separating water-soluble copper in step S1 comprises: using ascorbic acid and Na₂S₂O₃And dissolving out the water-soluble copper under the alkalescent condition.

4. A method for chemical analysis of copper phases in copper concentrates according to claim 3, characterized in that the weak alkaline condition is ph 7.5-8.5.

5. The method for chemical analysis of copper phases in copper concentrate according to claim 4, characterized in that the method for separating water-soluble copper in step S1 is embodied as follows: compounding ascorbic acid and Na₂S₂O₃And adjusting the pH value to 8, adding a sample to be detected into the mixed solution, stirring, and filtering to obtain a filtrate sample 1 containing water-soluble copper.

6. The method for chemical analysis of copper phases in copper concentrate according to claim 5, characterized in that the method for separating water-soluble copper in step S1 is embodied as follows: the ascorbic acid and Na₂S₂O₃The mixed solution of (1) is prepared by adding 1g Na into 50ml 2.5% ascorbic acid solution₂S₂O₃。

7. The method for chemical analysis of copper phases in copper concentrates according to claim 1 or 2, characterized in that the method for separating copper oxide in step S2 is embodied as follows: adding the filter residue obtained in the step S1 into a mixture of 50mL of 3% ethylenediamine solution, 0.125g of sodium 2, 3-dimercaptopropane sulfonate and 1.5g of NH₄Cl and 2gNa₂SO₃The prepared mixed solution is leached for 30min at 37 ℃ and then filtered to obtain a filtrate sample 2.

8. The method for chemical analysis of copper phases in copper concentrates according to claim 1, characterized in that the method for separating native copper in step S3 is embodied as follows: adding the filter residue obtained in the step S2 into a mixture of 50mL of 30g/L hydroxylamine hydrochloride and 20g/LHgCl₂-ethanol solution for 30min and filtering to obtain filtrate sample 3.

9. The method of chemical analysis of copper phases in copper concentrates according to claim 1, characterized in that an air-acetylene flame is used to draw a working curve at the wavelength 324.7nm of an atomic absorption spectrometer with copper concentration as abscissa and absorbance as ordinate.

10. The method for the chemical analysis of the copper phase in the copper concentrate according to any one of claims 1 to 9, characterized in that the absorbance of the solution to be measured of sample 1, sample 2, sample 3 is measured at the wavelength of 324.7nm of an atomic absorption spectrometer, and the content of water-soluble copper, copper oxide and native copper is calculated.

Background

Copper is an important strategic resource, with an average content of 1 × 10 in the crust^-2Copper is a typical thiophilic element, and the primary minerals of the copper are almost all sulfides, so that single hydrothermal deposits and skarn deposits of various types can be formed, magma nickel type or cobalt copper type deposits can be formed together with nickel and cobalt, and copper-containing polymetallic deposits can be formed together with lead and zinc. There are over 200 copper minerals found in nature, and there are more than ten common copper minerals, the main copper minerals being chalcopyrite, bornite, chalcocite, covellite, tetrahedrite, tennantite, malachite, chalcocite, cuprite, tenorite, spaghite, pincelite, native copper, chalcanthite, etc., which form in different geological environments of different genesis copper deposits and constitute copper ores of different types.

For many years, copper ores are listed as urgent mineral resources in China, and need to be imported in large quantities every year. The imported copper ore in China is generally copper concentrate which is subjected to flotation in foreign mines and has higher grade, the copper concentrate is an important resource commodity in imported raw materials in China, in 2020, the imported copper concentrate at various ports in China is about 2200 ten thousand tons, and the copper concentrate is generally bulk cargo and is free of package, so that the influence on the environment is great. The total copper content of the imported copper concentrate is determined by chemical analysis method GB/T3884.1 (determination of copper content: iodometry) for tax-related assays and trade settlement, and this occurs when the imported copper concentrate is contaminated with solid waste "blending-off". Whereas for the solid waste "mix-off" case, the identification of the doping of the imported copper concentrate is required, the traditionally used method is X-ray fluorescence spectroscopy (XRF) combined with X-ray diffraction (XRD). The XRF combined with XRD method is only qualitative but not accurate and quantitative for various copper phases in the imported copper concentrate.

For the reasons mentioned above, at present, the inspection and identification work of the imported copper concentrate includes quantitative determination of the total copper content and qualitative analysis of the main copper phase, and there is no method for quantitative analysis of the main copper phase in the imported copper concentrate. According to literature search, a small amount of chemical analysis methods for copper phases in copper ores exist at present, the composition of the copper phases of the imported copper concentrates and the original copper ores is different, and water-soluble copper possibly exists in the imported copper concentrates, so that a method for separating and determining main copper phases in the imported copper concentrates needs to be developed.

In addition, the national standard GB/T3884.1-2012 describes the use of iodometry to measure the total copper content, wherein, in the treatment of the sample, the dissolution of copper is assisted by the addition of liquid bromine, which is easily volatilized, and at normal temperature, it can volatilize smoke with strong irritation, irritate the mucous membranes of eyes and respiratory tract, burn the skin, and have strong toxicity and corrosiveness to the human body. Therefore, there is a need for a non-toxic and harmless way to replace liquid bromine in the chemical analysis of copper phases in copper concentrates.

Disclosure of Invention

1. Problems to be solved

The invention aims to provide a set of sequential extraction and determination methods for different copper phases contained in imported copper concentrates. The establishment of the method not only has good guiding significance for copper concentrate smelting enterprises in the aspects of raw material purchase, use, proportioning and the like, but also can effectively judge the condition of doping solid wastes in imported copper concentrates, thereby achieving the purpose of protecting the ecological environment.

Aiming at the problem that liquid bromine is adopted to dissolve out copper sulfide in the existing national standard, the invention provides a chemical analysis method for copper phases in copper concentrate, which adopts the coordination of dilute nitric acid and dilute sulfuric acid, avoids the adoption of liquid bromine with strong toxicity, and ensures that the determination process is safer.

The invention also aims to solve the problem that the existing pure water leaching method for water-soluble copper is inaccurate in measuring the content of the water-soluble copper due to iron ions, and the ascorbic acid and the Na are adopted₂S₂O₃And the technical scheme of dissolving out the water-soluble copper under the alkalescent condition can effectively avoid the influence of iron ions on the water-soluble copper.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a method for chemical analysis of copper phases in copper concentrates, comprising the steps of:

s1, separating water-soluble copper in the copper concentrate to be detected, and determining the content of the water-soluble copper by adopting an atomic absorption method;

s2, separating the copper oxide in the filter residue A obtained in the step S1, and determining the content of the copper oxide by adopting an atomic absorption method;

s3, separating the native copper in the filter residue B obtained in the step S2, and determining the content of the native copper by adopting an atomic absorption method;

s4, separating the copper sulfide in the filter residue C obtained in the step S3, and determining the content of the copper sulfide by adopting a titration method;

wherein the step of separating copper sulfide in the step of S4 includes:

firstly, heating and dissolving the filter residue C by using dilute nitric acid, then adding dilute sulfuric acid to continue heating and decomposing, then evaporating the solution to dryness, adding dilute sulfuric acid to heat and dissolve to obtain a mixture of copper and iron, then masking iron and determining the content of copper sulfide by using a titration method.

Preferably, the step of separating copper sulfide in the step of S4 includes:

putting the filter residue in a cone-shaped beaker, wetting the filter residue with a small amount of distilled water, adding 20 ml of dilute nitric acid (50%), covering a watch glass, heating the watch glass for 10 minutes at 180 +/-5 ℃, adding 20 ml of dilute sulfuric acid (50%), continuously heating to decompose a sample, cleaning the watch glass with a small amount of water after a violent reaction stops (about 1-2 hours), continuously heating at a high temperature (about 300 ℃) until dense white smoke is emitted, taking the watch glass down after the dense white smoke is completely dispersed, and cooling. The wall of the flask was washed with a small amount of distilled water and then heated to near dryness. Adding 10mL of 0.5% dilute sulfuric acid, heating to dissolve soluble salt, adding 30mL of distilled water, heating to slightly boil to completely dissolve, taking down and cooling to room temperature to completely dissolve the generated copper salt.

Preferably, the method for separating water-soluble copper in step S1 includes: using ascorbic acid and Na₂S₂O₃And dissolving out the water-soluble copper under the alkalescent condition.

Further preferably, the weak alkaline condition is pH 7.5-8.5.

Preferably, the method for separating water-soluble copper in step S1 specifically includes: compounding ascorbic acid and Na₂S₂O₃And adjusting the pH value to 8, adding a sample to be detected into the mixed solution, stirring, and filtering to obtain a filtrate sample 1 containing water-soluble copper.

Further preferably, the method for separating water-soluble copper in step S1 specifically includes: the ascorbic acid and Na₂S₂O₃The mixed solution of (1) is prepared by adding 1g Na into 50ml 2.5% ascorbic acid solution₂S₂O₃。

Preferably, the method for separating copper oxide in step S2 specifically includes: adding the filter residue obtained in the step S1 into a mixture of 50mL of 3% ethylenediamine solution, 0.125g of sodium 2, 3-dimercaptopropane sulfonate and 1.5g of NH₄Cl and 2gNa₂SO₃The prepared mixed solution is leached for 30min at 37 ℃ and then filtered to obtain a filtrate sample 2.

Preferably, the method for separating native copper in step S3 specifically includes: adding the filter residue obtained in the step S2 into a mixture of 50mL of 30g/L hydroxylamine hydrochloride and 20g/LHgCl₂-ethanol solution for 30min and filtering to obtain filtrate sample 3.

Preferably, before step S1, the elements in the sample to be tested are first qualitatively analyzed by X-ray fluorescence spectroscopy (XRF).

Preferably, before step S1, the copper phase in the sample to be tested is first qualitatively analyzed by X-ray diffraction (XRD) according to the XRF qualitative result, so as to obtain the categories of water-soluble copper, copper oxide, native copper and copper sulfide in the sample to be tested.

Preferably, an air-acetylene flame is used to plot the operating curve at an atomic absorption spectrometer wavelength of 324.7nm with copper concentration on the abscissa and absorbance on the ordinate.

Preferably, the absorbance of the solution to be detected of the samples 1, 2 and 3 is measured at the wavelength of 324.7nm of the atomic absorption spectrometer, and the content of the water-soluble copper, the copper oxide and the native copper is calculated.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) aiming at the fact that no method for respectively measuring different phases in copper concentrate exists in the prior art, the method adopts a step-by-step extraction method to obtain the copper of phases of water-soluble copper, copper oxide, native copper and copper sulfide in the copper concentrate, and measures the copper content of various phases; in addition, aiming at the copper sulfide phase in the copper concentrate, dilute nitric acid and dilute sulfuric acid are used in a matched mode to dissolve out copper in the copper sulfide phase, so that liquid bromine with strong toxicity in the national standard GB/T3884.1-2012 is avoided, and the determination process is safer;

(2) in the prior art, the water-soluble copper phase in the copper concentrate is only extracted by distilled water at room temperature or under a heating condition, but the treatment method has the following problems: firstly, zinc blende exists in part of imported copper concentrate, and CuS precipitate is generated when the imported copper concentrate is immersed in water, so that the determination of water-soluble copper is low; secondly, the imported copper concentrate usually contains ferric sulfate and enters a solution together with water-soluble copper, so that part of copper sulfide is dissolved, and the determination of the water-soluble copper is higher; therefore, it is difficult to obtain accurate measurement results simply by immersing the water-soluble copper with distilled water at room temperature or under heating conditions; the invention adopts ascorbic acid and Na₂S₂O₃Dissolving out water-soluble copper under alkalescent condition, forming a complex by ascorbic acid and iron, and then passing Na₂S₂O₃Dissolving out copper, effectively avoiding iron ions from dryingThe problem of inaccurate measurement of the water-soluble copper caused by interference;

(3) according to the method, through chemical solution pretreatment, water-soluble copper, copper oxide and native copper are leached out respectively, an atomic absorption spectrometer is used for accurately measuring, and the pretreated filter residue is dissolved and titrated to obtain an accurate value; the establishment of the method can improve the current situation that the main copper phase in the imported copper concentrate cannot be quantified at present, has good guiding significance for copper concentrate smelting enterprises in the aspects of raw material purchase, use, proportion and the like, and can also effectively judge the condition of doping solid wastes in the imported copper concentrate, thereby achieving the purpose of protecting the ecological environment.

(4) The method judges the category of the main copper phase in the sample in advance by combining X-ray fluorescence spectrometry (XRF) with X-ray diffraction (XRD) according to the chemical analysis method of the copper phase in the imported copper concentrate, and reasonably draws up the experimental flow.

Drawings

FIG. 1 is a flow chart of an experiment in example 1 of the present invention;

FIG. 2 is an XRF spectrum of copper concentrate of example 2;

FIG. 3 is the XRD pattern of copper concentrate in example 2; (Ccp: chalcopyrite; Bn: bornite; Cv: covellite; Clt: chalcanthite; Py: pyrite; Q: quartz)

FIG. 4 is an XRF spectrum of copper concentrate of example 3;

figure 5 is the XRD pattern of copper concentrate in example 3.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; as used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The invention is further described with reference to specific examples.

Example 1

According to the early experimental results and the significance of various copper phases in relative smelting and customs supervision, the various copper phases in the imported copper concentrate can be divided into four main classes, namely water-soluble copper (mainly chalcanthite and brucite), copper oxide (mainly cuprite and chalcopyrite), native copper and copper sulfide (mainly chalcopyrite, bornite, chalcocite and copper blue). The chemical analysis method for the copper phase in the copper concentrate mainly comprises the following experimental steps:

1. after a representative sample is taken according to the specification, uniformly mixing, dividing and grinding the sample, and sieving the sample with a 150-mesh sieve to obtain a sample to be detected;

2. qualitatively analyzing elements in the sample to be detected by using an X fluorescence spectrometry (XRF);

3. carrying out qualitative analysis on the copper phase in the sample to be detected by utilizing an X-ray diffraction method (XRD) according to an XRF qualitative result to obtain the categories of water-soluble copper, copper oxide, native copper and copper sulfide in the sample to be detected;

4. drawing up an experimental flow according to the categories obtained by the analysis, and sequentially measuring the water-soluble copper, the copper oxide, the native copper and the copper sulfide as shown in figure 1;

5. determination of water-soluble copper: preparing 50 mL2.5% ascorbic acid solution, adding 1gNa₂S₂O₃Adjusting the pH value to 8, accurately weighing 10g of a sample to be detected, adding the sample to the solution, stirring for 10min, filtering, transferring the filtrate into a 200mL volumetric flask, diluting the filtrate to a scale with water, uniformly mixing, standing for 2h, marking a sample 1, and washing filter residue A for later use;

6. determination of copper oxide: 50mL of 3% ethylenediamine solution was prepared, and 0.125g of 2, 3-dimercaptopropane sulfonic acid sodium salt and 1.5g of NH were added₄Cl and 2gNa₂SO₃Adding the filter residue A into the solution, leaching for 30min at 37 ℃, filtering, transferring the filtrate into a 200mL volumetric flask, diluting with water to a scale, uniformly mixing, standing for 2h, marking a sample 2, and washing the filter residue B for later use;

7. and (3) determination of native copper: 50mL of 30g/L hydroxylamine hydrochloride and 20g/LHgCl are prepared₂-ethanol solution, adding the residue B, further leaching for 30min, filtering and transferring the filtrate to 200mLDiluting the mixture to a scale with water in a volumetric flask, uniformly mixing, standing for 2 hours, marking a sample 3, and washing filter residue C for later use;

8. determination of copper sulfide: placing the filter residue C in a 300 ml conical beaker, wetting the filter residue C with a small amount of distilled water, and adding 20 ml of 50% dilute nitric acid (dissolving copper sulfide phases CuS + FeS + HNO)₃→Cu²⁺+Fe²⁺+NO₃ ^-) Covering the surface dish, heating at about 180 deg.C (180 + -5 deg.C) for 10min, and adding 20 ml of 50% dilute sulfuric acid (capable of dissolving copper sulfide phase completely into Cu²⁺+Fe²⁺+NO₃ ^-+H₂SO₄→Cu²⁺+Fe³⁺+SO₄ ^2-) And continuously heating to decompose the sample, after the violent reaction is stopped (about 1-2 hours), cleaning and removing the surface dish by using a small amount of water, continuously heating at a high temperature (about 300 ℃) until dense white smoke is emitted (sulfur and nitrogen are removed), taking down the sample after the dense white smoke is completely dispersed, and cooling. The wall of the flask was washed with a small amount of distilled water and then heated to near dryness (to make the resulting copper salt non-stick to the wall). Adding 10mL of 0.5% dilute sulfuric acid, heating to dissolve soluble salt, adding 30mL of distilled water, heating to slightly boil to completely dissolve, taking down and cooling to room temperature to completely dissolve generated copper salt;

an appropriate amount of acetic acid-ammonium acetate buffer solution was added until the red color of the solution did not deepen, and 3 ml of excess was added (the acidity of the solution was adjusted to pH 3-4). Adding a proper amount of saturated ammonium bifluoride solution until the red color fades, and adding 1ml of saturated ammonium bifluoride solution (masking Fe)³⁺+NH₄HF₂→(FeF₆)^3-). Adding about 3g of potassium iodide powder in excess (the excess potassium iodide powder causes copper iodide ions and iodine ions to generate copper iodide precipitate and elementary iodine Cu²⁺+I^-→CuI+I₂) The solution turns brown and is immediately titrated to light yellow by a sodium thiosulfate standard solution (sodium thiosulfate reacts with iodine simple substance, the iodine simple substance is gradually reduced, and the solution becomes light I₂+S₂O₃ ^2-→I^-+S₄O₆ ^2-) Adding 5ml of starch solution (starch turns blue when meeting iodine, and checking whether iodine simple substance completely reacts), continuing to titrate until blue color basically disappears, and adding 5ml of potassium thiocyanate (100g/L) (thiocyanate radical)Reacts with copper iodide to form more insoluble copper thiocyanide and iodine simple substance, so that the wrapped copper ions are further precipitated to be completely CuI + SCN^-→CuSCN+I₂) And continuously titrating until the blue color just disappears, namely the end point, and calculating to obtain the copper sulfide.

9. Preparing a copper standard curve: transferring 0mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL and 5.00mL of copper standard solution, respectively placing in a group of 200mL volumetric flasks, adding 1.0mL of sulfuric acid, diluting with water to a scale, and uniformly mixing;

10. drawing a working curve: using air-acetylene flame, adjusting the wavelength of an atomic absorption spectrometer to 324.7nm by water to zero, measuring the absorbance of the solution, subtracting the absorbance of the solution with zero concentration, and drawing a working curve by taking the concentration of copper as an abscissa and the absorbance as an ordinate;

11. determination of samples 1 to 3: and (3) measuring the absorbance of the solution to be measured of the samples 1-3 at the wavelength of 324.7nm of an atomic absorption spectrometer by using air-acetylene flame, and calculating to obtain the content of the water-soluble copper, the copper oxide and the native copper.

Example 2

An import copper concentrate sample is processed according to the experimental procedure in example 1 to obtain XRF and XRD patterns as shown in fig. 2 and fig. 3, which show that the import copper concentrate sample contains phases of chalcanthite (water soluble copper), cuprite (copper oxide), chalcopyrite and bornite (copper sulfide), and the content of native copper is low and is not clearly shown in the patterns.

The contents of the water-soluble copper, the copper oxide and the native copper measured by adopting an atomic absorption spectrometry are respectively as follows: 6.05% (allocated, i.e. 25.74% of the total copper content), 0.15% (allocated 0.64%), 0.08% (allocated 0.34%); the copper sulphide content was determined by titration to be 17.20% (partition 73.28%) and the total copper content was 23.48%.

Copper sulfate and copper sulfide are artificially added into the imported copper concentrate, and a standard addition recovery experiment is carried out, so that the recovery rate is 90-110%, and the accuracy of the method can be verified.

Comparative example A

Aiming at the same batch of copper concentrate samples to be tested which are sieved by a 150-mesh sieve in the embodiment 2; the total copper content was determined using the liquid bromine method described in the national standard GB/T3884.1-2012, i.e.:

determination of total copper: putting the filter residue in a 500mL triangular beaker, wetting the filter residue with a small amount of water, adding 10mL hydrochloric acid, putting the beaker on an electric hot plate, heating the beaker at a low temperature for 5min, taking the beaker down for cooling slightly, adding 5mL nitric acid and 1mL bromine, covering a watch glass, mixing the cells uniformly, heating the beaker at a low temperature of about 60 ℃, taking the beaker down for cooling slightly after a sample is completely decomposed, washing the watch glass with a small amount of water, continuously heating and steaming the beaker until the sample is nearly dry, and cooling the beaker. An appropriate amount of acetic acid-ammonium acetate buffer solution was added until the red color of the solution did not deepen, and 3 ml of excess was added (the acidity of the solution was adjusted to pH 3-4). Adding a proper amount of saturated ammonium bifluoride solution until the red color fades, and adding 1ml of saturated ammonium bifluoride solution (masking Fe)³⁺+NH₄HF₂→(FeF₆ ^)3-). Adding about 3g of potassium iodide powder in excess (the excess potassium iodide powder causes copper iodide ions and iodine ions to generate copper iodide precipitate and elementary iodine Cu²⁺+I^-→CuI+I₂) The solution turns brown and is immediately titrated to light yellow by a sodium thiosulfate standard solution (sodium thiosulfate reacts with iodine simple substance, the iodine simple substance is gradually reduced, and the solution becomes light I₂+S₂O₃ ^2-→I^-+S₄O₆ ^2-) Adding 5ml of starch solution (starch turns blue when meeting iodine, and checking whether the iodine elementary substance completely reacts), continuing to titrate until the blue color basically disappears, and then adding 5ml of potassium thiocyanate (100g/L) (thiocyanate and copper iodide react to form more insoluble copper thiocyanate and iodine elementary substance, so that the wrapped copper ions are further precipitated to completely precipitate CuI + SCN^-→CuSCN+I₂) And continuously titrating until the blue color just disappears, namely the end point, and calculating to obtain the copper sulfide.

With this method, the total copper content was found to be 23.56%.

And (4) conclusion: the method of the national standard only measures the total content of copper element in the imported copper concentrate by adopting an acid-soluble pretreatment method, but the method utilizes a plurality of reagents to leach out water-soluble copper, copper oxide and native copper, and measures copper sulfide by an improved method to obtain the content of each phase in the imported copper concentrate, rather than the content of the copper element.

Example 3

Another batch of imported copper concentrate is processed according to the experimental flow in example 1 to obtain XRF and XRD patterns as shown in fig. 4 and 5, so that the imported copper concentrate sample contains phases of cuprite (copper oxide) and chalcopyrite (copper sulfide), and the content of water-soluble copper is low and is not clearly shown in the patterns.

The contents of the water-soluble copper, the copper oxide and the native copper measured by adopting an atomic absorption spectrometry are respectively as follows: 0.008% (allocated 0.03%), 0.026% (allocated 0.10%), 0% (allocated 0%); the copper sulphide content was determined by titration to be 26.30% (partition 99.87%).

Copper sulfate and copper sulfide are artificially added into the imported copper concentrate, and a standard addition recovery experiment is carried out, so that the recovery rate is 90-110%, and the accuracy of the method can be verified.

The above description is illustrative of the present invention and its embodiments, and is not to be construed as limiting, and the embodiments shown in the examples are only one embodiment of the present invention, and the actual embodiments are not limited thereto. Therefore, if the person skilled in the art receives the teaching, the embodiment and the embodiment similar to the technical solution should be designed without creativity without departing from the spirit of the invention, and shall fall within the protection scope of the invention.