Construction method and application of standard curve for determining gold content in gold ore

Abstract

The invention relates to a construction method and application of a standard curve for determining the gold content in gold ore. The construction method comprises the following steps: (1) preparing a gold standard solution: adding aqua regia into pure gold, heating and dissolving to obtain a dissolved solution, then adding potassium chloride into the dissolved solution, carrying out water bath evaporation to dryness, then adding hydrochloric acid, slightly heating and dissolving, diluting with water, and shaking uniformly to obtain a gold standard intermediate solution; sucking the gold-labeled intermediate solution, and adding diisobutyl ketone for extraction to obtain a gold standard solution; (2) construction of a standard curve: determining the absorbance of the gold standard solution by using an atomic absorption spectrophotometer, establishing a working curve, and calibrating the working curve according to the fixed value of the gold standard solution to obtain the standard curve. According to the construction method and application of the standard curve for determining the gold content in the gold ore, the method is low in cost, rapid, high in accuracy and capable of meeting the production requirement and has very important significance on determination of the gold content in the gold ore.

Description

Technical Field

[0001] The invention relates to the technical field of chemical detection and analysis, and in particular to a method for constructing a standard curve for determining the amount of gold in a gold ore and an application thereof. Background Art

[0002] The content of gold in nature is extremely low, and its abundance in the earth's crust is about 1ng / g, which brings difficulties to the measurement of gold. Usually, when measuring gold, gold is first enriched by a certain method, and then directly measured according to different enrichment methods or prepared into a gold-containing solution after pretreatment and then measured. Common enrichment methods include: fire assay, activated carbon adsorption, foam adsorption and ion exchange. The enrichment of gold is a very important process. It not only separates gold from matrix elements to eliminate interference, but also enriches gold to achieve detection. The measurement methods of gold after enrichment usually include: gravimetric method, emission spectroscopy, iodine titration, spectrophotometry, atomic absorption spectroscopy and inductively coupled plasma mass spectrometry.

[0003] Fire assay is a mature and classic method. Currently, there are methods such as lead assay, antimony assay, tin assay and bismuth assay. Among them, lead assay is the most reliable analysis method and has been listed as a national standard by many countries. However, fire assay has very high requirements on the operating skills of the testers. The operation is complicated and there are many uncertain factors in the operation process. The analysis process takes about 6 hours. The activated carbon adsorption method has simple equipment, saves reagents, and does not pollute the environment, but the analysis process also takes about 6 hours. Although the activated carbon enrichment flame method and foam enrichment-atomic absorption method have their own advantages, the processes are relatively long, and the timeliness of the analysis data cannot fully meet the needs of the production plant for analysis data. In order to meet the production needs, it is of great significance to seek a low-cost, fast, and accurate method that can meet the production needs for the determination of the gold content of gold ore. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a low-cost, fast and accurate method for detecting the amount of gold in gold ore that can meet the requirements of production and scientific research. The present invention realizes the rapid enrichment pretreatment of gold ore samples, greatly shortens the detection time, and has good accuracy, precision and applicability.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] The first object of the present invention is to provide a method for constructing a standard curve for determining the amount of gold in gold ore, comprising the following steps:

[0007] (1) preparing a gold standard solution: adding aqua regia to pure gold and heating to dissolve to obtain a solution, then adding potassium chloride to the solution in a water bath to evaporate to dryness, then adding hydrochloric acid to dissolve under slight heat, and then diluting with water to obtain a gold standard intermediate solution; taking a series of the gold standard intermediate solutions, respectively adding diisobutyl ketone to extract, and diluting to obtain a series of gold standard solutions with concentration gradients;

[0008] (2) Construction of standard curve: The absorbance of a series of gold standard solutions with different concentration gradients is measured by an atomic absorption spectrophotometer to establish a working curve, and the working curve is calibrated by the fixed value of the gold standard solution to obtain a standard curve.

[0009] The beneficial effects of the present invention are as follows: the present invention provides a method for constructing a standard curve for determining the amount of gold in gold ore, which is low-cost, fast, and highly accurate, can meet production needs, and is of great significance for the determination of the amount of gold in gold ore.

[0010] Based on the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, the usage ratio of the pure gold, the aqua regia, the potassium chloride and the hydrochloric acid is 0.1 g: 8-12 mL: 0.1-0.3 g: 8-12 mL.

[0012] Furthermore, the concentration of the hydrochloric acid is 1 to 2 g / mL.

[0013] Furthermore, the concentration of the gold-labeled intermediate solution in step (1) is 100 μg / mL.

[0014] Furthermore, the volume ratio of the gold-labeled intermediate solution to the diisobutyl ketone is (0-5):100.

[0015] Furthermore, the absorbance is the absorbance at a wavelength of 242.8 nm.

[0016] The second object of the present invention is to provide an application of a standard curve for determining the amount of gold in a gold ore, wherein the standard curve is applied to the detection of the amount of gold in a gold ore, comprising the following steps:

[0017] (1) Weighing a gold ore sample to be tested with a mass of m and burning it to obtain a burnt product, taking out the burnt product, cooling it, and adding aqua regia to dissolve it to obtain a solution, adding diisobutyl ketone with a volume of V to the solution, shaking and extracting it, and then adding water to make up the volume, and standing it for phase separation to obtain a sample solution;

[0018] (2) preparing a blank sample: taking another portion of the aqua regia and adding a volume V of diisobutyl ketone, oscillating and extracting, adding water to make up the volume, and standing to separate the phases to obtain a blank solution;

[0019] (3) The sample solution is measured for the absorbance of gold by an atomic absorption spectrophotometer, and the mass concentration of gold in the sample solution ρ and the concentration of gold in the blank sample ρ are obtained according to the standard curve. (0) , through the formula ω (Au) =(ρ-ρ 0 )×V / m to calculate the gold content in the test solution ω (Au) .

[0020] The beneficial effects of the present invention are as follows: the present invention first burns the sample, then dissolves the burned sample with aqua regia, directly extracts gold with quantitative diisobutyl ketone, and then directly measures the gold content in the organic phase with flame atomic absorption spectrometry to calculate the gold content in the sample. The detection process is fast and simple, the detection result has a small relative deviation and high precision.

[0021] Furthermore, the calcination is specifically carried out from 25°C to 650°C, the heating time is 35-50 minutes, and the calcination is carried out for 2 hours to fully burn out the sulfur and organic matter in the sample, and arsenic and sulfur do not need to be calcined.

[0022] Furthermore, the usage ratio of the gold ore sample, the aqua regia, and the diisobutyl ketone is (5-20) g:80 mL:(5-10 mL).

[0023] Furthermore, the volume concentration of the aqua regia is 40% to 55%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a standard curve diagram of Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0026] Example 1: Construction of a standard curve for determining the amount of gold in gold ore

[0027] (1) Prepare gold standard solution: weigh 0.1000 g pure gold into a 250 mL beaker, add 10 mL aqua regia (the volume ratio of aqua regia to water is 1:1) and heat to dissolve, then add 0.1 g potassium chloride and evaporate to dryness in a 100°C water bath, then add 10 mL hydrochloric acid (analytical grade, concentration of 1.19 g / mL) and dissolve under slight heat, transfer to a 1000 mL volumetric flask, dilute to the mark with water, and shake well to obtain a gold standard intermediate solution. 1 mL of the gold standard intermediate solution contains 100 μg gold;

[0028] (2) 0 mL, 0.50 mL, 1.00 mL, 2.00 mL, and 5.00 mL of the gold standard intermediate solution in step (1) were respectively taken and added into 100 mL of diisobutyl ketone for extraction for 5 minutes to prepare 5 gold standard solutions of different concentrations. Each mL contained 0 μg, 0.50 μg, 1.00 μg, 2.00 μg, and 5.00 μg Au, respectively;

[0029] (3) Construction of standard curve: The absorbance of five gold standard solutions of different concentrations prepared in step (2) was measured using an atomic absorption spectrophotometer (240FS; Agilent); the absorbance of the gold standard solution was measured using an atomic absorption spectrophotometer to establish a working curve, and the working curve was calibrated using a fixed value of the gold standard solution to obtain a standard curve equation y=0.0489x+0.000009, wherein x is the concentration; y is the absorbance.

[0030] Example 2: Application of a standard curve for determining the amount of gold in gold ore

[0031] (1) Weighing a gold ore sample A with a mass of m = 10 g, heating the sample from 25° C. to 650° C. for 35 to 50 min, roasting the sample for 2 hours to obtain a burnt product, taking out the burnt product, cooling it, and adding aqua regia (the volume ratio of aqua regia to water is 1:1) to dissolve the product to obtain a solution, adding diisobutyl ketone with a volume of V = 5 mL to the solution, shaking and extracting it, and then adding water to make up the volume, and allowing it to stand for phase separation to obtain a sample solution;

[0032] (2) Prepare a blank sample: Take another portion of aqua regia and add V = 5 mL of diisobutyl ketone, shake and extract, then add water to make up the volume, let stand and separate the phases to obtain a blank solution;

[0033] (3) The sample solution was measured for the absorbance of gold by an atomic absorption spectrophotometer. According to the standard curve constructed in Example 1, the mass concentration of gold in the sample solution was ρ = 4.82 mg / L and the concentration of gold in the blank sample was ρ = 4.82 mg / L. (0) =0mg / L, through the formula ω (Au) =(ρ-ρ 0 )×V / m to calculate the gold content in the test solution ω (Au) =2.41g / t.

[0034] Example 3: Application of the standard curve for determining the amount of gold in gold ore

[0035] (1) Weighing a gold ore sample B to be tested with a mass of m = 10 g, heating the sample from 25° C. to 650° C. for 35 to 50 min, roasting the sample for 2 hours to obtain a burnt product, taking out the burnt product, cooling it, and adding aqua regia (the volume ratio of aqua regia to water is 1:1) to dissolve the product to obtain a solution, adding diisobutyl ketone with a volume of V = 5 mL to the solution, shaking and extracting it, and then adding water to make up the volume, and allowing it to stand for phase separation to obtain a sample solution;

[0036] (2) Prepare a blank sample: Take another portion of aqua regia and add V = 5 mL of diisobutyl ketone, shake and extract, then add water to make up the volume, let stand and separate the phases to obtain a blank solution;

[0037] (3) The sample solution was measured for the absorbance of gold by an atomic absorption spectrophotometer. According to the standard curve of Example 1, the mass concentration of gold in the sample solution was ρ = 2.2 mg / L and the concentration of gold in the blank sample was ρ = 2.2 mg / L. (0) =0mg / L, through the formula ω (Au) =(ρ-ρ 0 )×V / m to calculate the gold content in the test solution ω (Au) =1.10g / t.

[0038] Comparative Example 1: Fire assay method to measure the gold content in gold ore

[0039] The national standard method GB / T20899.1-2019 was used to test the gold ore sample A. Comparative Example 2: Fire assay method was used to measure the gold content in the gold ore.

[0040] The national standard method GB / T20899.1-2019 is used to test the gold ore sample B:

[0041] 1. The measured values ​​of gold element in Examples 2-3 and Comparative Examples 1-3 are shown in Table 1 below;

[0042] 2. Example 2 and Example 3 were measured 7 times in parallel, and the relative standard deviation (RSD) was calculated. The results are shown in Table 2:

[0043] Table 1

[0044] Example 2 Example 3 Comparative Example 1 Comparative Example 2 Au(g / t) 2.46 1.11 2.52 1.05

[0045] Table 2

[0046]

[0047]

[0048] From Table 1-2, we can get:

[0049] (1) Comparison of the results in Table 1 shows that the results of Example 2 and Example 3 using the method of the present invention are basically consistent with the results of fire assay analysis, and the difference in the results is within the range of the method operation difference of "GBT 20899.1-2019 Chemical Analysis Methods for Gold Ore Part 1: Determination of Gold Content", indicating that the method has good accuracy. This method can achieve the effect of rapid and accurate detection.

[0050] (2) Comparison of the results in Table 2 shows that, from the above data, the relative standard deviations of Example 2 and Example 3 are both less than 4%, and the method accuracy is good, indicating that the determination results of this method are reliable. Moreover, the present invention can be used to simply, quickly and at low cost determine the amount of gold in gold ore, and a single sample can be tested in about 150 minutes.

[0051] (3) The gold content spiked recovery rate of the gold ore obtained by the present invention is between 95% and 105%, the relative standard deviation is less than 4%, and the quantitative lower limit of the method is 0.05 g / t.

[0052] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for constructing a standard curve for determining the amount of gold in gold ore, characterized in that: The method comprises the following steps: (1) preparing a gold standard solution: adding aqua regia to pure gold and heating to dissolve to obtain a solution, then adding potassium chloride to the solution and evaporating to dryness, then adding hydrochloric acid to dissolve, and then making up to volume with water to obtain a gold standard intermediate solution; A series of gold standard intermediate solutions are drawn, and diisobutyl ketone is added for extraction, and the volume is fixed to obtain a series of gold standard solutions with concentration gradients; (2) Construction of standard curve: The absorbance of a series of gold standard solutions with different concentration gradients is measured by an atomic absorption spectrophotometer to establish a working curve, and the working curve is calibrated by the fixed value of the gold standard solution to obtain a standard curve.

2. The method for constructing a standard curve for determining the amount of gold in gold ore according to claim 1, characterized in that: The usage ratio of the pure gold, the aqua regia, the potassium chloride and the hydrochloric acid is 0.1 g: 8-12 mL: 0.1-0.3 g: 8-12 mL.

3. The method for constructing a standard curve for determining the amount of gold in gold ore according to claim 2, characterized in that: The concentration of the hydrochloric acid is 1-2 g / mL.

4. The method for constructing a standard curve for determining the amount of gold in gold ore according to claim 1, characterized in that: The concentration of the gold-labeled intermediate solution in step (1) is 100 μg / mL.

5. The method for constructing a standard curve for determining the amount of gold in gold ore according to claim 4, characterized in that: The volume ratio of the gold-labeled intermediate solution to the diisobutyl ketone is (0-5):

100.

6. The method for constructing a standard curve for determining the amount of gold in gold ore according to claim 1, characterized in that: The absorbance is the absorbance at a wavelength of 242.8 nm.

7. An application of a standard curve for determining the amount of gold in a gold ore, characterized in that: Weigh a gold ore sample to be tested with a mass of m and burn it to obtain a burnt product, take out the burnt product, cool it, and then add aqua regia to dissolve it to obtain a solution, add diisobutyl ketone with a volume of V to the solution, shake and extract it, then add water to make up the volume, and let it stand for phase separation to obtain a sample solution; (2) preparing a blank sample: taking another portion of the aqua regia and adding a volume V of diisobutyl ketone, oscillating and extracting, adding water to make up the volume, and standing to separate the phases to obtain a blank solution; (3) measuring the absorbance of gold in the sample solution by an atomic absorption spectrophotometer, and obtaining the mass concentration of gold in the sample solution ρ and the concentration of gold in the blank sample ρ according to the standard curve of any one of claims 1 to 6. (0) , through the formula ω (Au) =(ρ-ρ0)×V / mCalculate the gold content in the test solution ω (Au) .

8. The use of a standard curve for determining the amount of gold in gold ore according to claim 7, characterized in that: The calcination is specifically carried out from 25°C to 650°C, the heating time is 35 to 50 minutes, and the calcination is 2 hours.

9. The use of a standard curve for determining the amount of gold in gold ore according to claim 7, characterized in that: The usage ratio of the gold ore sample, the aqua regia and the diisobutyl ketone is 5-20 g:80 mL:5-10 mL.

10. The use of a standard curve for determining the amount of gold in gold ore according to claim 9, characterized in that: The volume concentration of the aqua regia is 40% to 55%.

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