Characterization method of occurrence state of gold in Carlin type gold ore

文档序号:855516 发布日期:2021-04-02 浏览:2次 中文

阅读说明:本技术 一种卡林型金矿中金的赋存状态的表征方法 (Characterization method of occurrence state of gold in Carlin type gold ore ) 是由 万泉 杨美稚 聂信 覃宗华 于文彬 于 2020-12-09 设计创作,主要内容包括:本发明涉及一种卡林型金矿中金的赋存状态的表征方法,包括以下步骤:将卡林型金矿原矿样品破碎浮选后得到精选的黄铁矿,采用HCl在对其进行超声刻蚀,后用无氧去离子水及无水乙醇洗涤,随后在真空烘箱中干燥,最后用XPS对其中金的价态进行测试分析。本发明的思路是把最外层不含金或金含量较低的环带用非氧化性的酸刻蚀掉,使能达到XPS检出限的富金环带暴露,随后就可以使用XPS获得想要的Au的赋存状态方面的信息。(The invention relates to a characterization method of occurrence state of gold in Carlin type gold mine, which comprises the following steps: crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite by adopting HCl, washing the selected pyrite by using oxygen-free deionized water and absolute ethyl alcohol, drying the selected pyrite in a vacuum oven, and finally testing and analyzing the valence state of gold in the selected pyrite by using XPS. The idea of the present invention is to etch the gold-free or low-gold-content zone at the outermost layer with a non-oxidizing acid to expose a gold-rich zone that can reach the detection limit of XPS, and then obtain information on the desired occurrence state of Au using XPS.)

1. A characterization method of occurrence state of gold in Carlin type gold ore is characterized by comprising the following steps: crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite by adopting HCl, washing the selected pyrite by using oxygen-free deionized water and absolute ethyl alcohol, drying the selected pyrite in a vacuum oven, and finally testing and analyzing the valence state of gold in the selected pyrite by using XPS.

2. The method for characterizing the occurrence of gold in carin-type gold ore according to claim 1, wherein the solid-to-liquid ratio of the beneficiated pyrite to the HCl solution is 1:10 to 1: 100.

3. The method according to claim 1, wherein the HCl concentration is 0.05-6 mol/L.

4. The characterization method of the occurrence state of gold in Carlin-type gold mine according to claim 1, wherein the ultrasonic frequency is 20-100 Hz, the ultrasonic frequency is 1-10 times, each ultrasonic time is 10 min-6 h, and after each ultrasonic time, the gold is washed and centrifuged with water for more than 1 time.

5. The method for characterizing the occurrence of gold in carin-type gold ore according to claim 1, wherein the ultrasonic etching temperature is 5-100 ℃.

6. The method according to claim 1, wherein the gold is washed with absolute ethanol more than 2 times after the ultrasonic etching.

7. The method according to claim 1, wherein the washed sample is dried under vacuum at a temperature of 5-80 ℃ for a period of 2 hours or more.

Technical Field

The invention relates to a characterization method of occurrence states of gold in Carlin type gold ores, and belongs to the technical field of mineral analysis.

Background

The Carlin type gold mine is a micro-fine particle impregnated gold mine mainly produced in clastic rock and carbonate rock construction, is mainly distributed in two 'gold triangular' zones of Yunnan Guigui and Chuangan Shaan in China and areas near the China, and is an important component of a global gold resource. The occurrence state of gold in the gold-loaded mineral is the basis for disclosing the enrichment and precipitation mechanism of the gold. Gold in the Carlin type gold ore is mainly existed in the arsenious pyrite, but the occurrence state and the distribution rule thereof have very obvious diversity, difference and complexity in different mining areas. Although the basic scientific research is still deepened along with the continuous breakthrough of the exploration and development of the karn type gold mine, the understanding of the occurrence state and the micro-causative mechanism of the gold in the karn type gold mine still has obvious defects or disputes, the restriction mechanism of the valence state and the occurrence form of the gold in the arsenic-containing pyrite is not certain, most of the mechanism is obtained by analyzing and conjecturing geochemical data of geological samples and a small amount of experimental and simulation results, and the mechanism is probably obviously inconsistent with the actual geological process.

The existence state of gold in Carlin-type gold ores was studied by a variety of methods. The most common method is Electron Probe Microanalysis (EPMA), which is mainly used to study gold content and surface distribution, but this method has a high detection limit and a low spatial resolution. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) can be used to analyze the elemental content of gold with a relatively low detection limit but a large analytical beam spot (at least 15 μm). Secondary Ion Mass Spectrometry (SIMS), particularly NanoSIMS, has a lower detection limit and a smaller analysis area, and can analyze the content and distribution of gold in gold-loaded minerals at a nanometer scale. The Transmission Electron Microscope (TEM) can analyze the microstructure of the gold-loaded mineral from the nanometer scale or even lower, and can directly observe the gold nanoparticles. However, none of the above methods can directly determine the valence state of gold-bearing minerals in the Carlin-type gold ore, especially gold in arsenic-containing pyrite. The X Photoelectron Spectroscopy (XPS) can accurately analyze the chemical valence state of gold in minerals, can detect the content and valence state of elements with the surface depth of 1nm to 10nm on solid matters, but has not been applied to the analysis of the occurrence state of gold in arsenious pyrite in Carlin type gold ore samples so far, and particularly, the valence state and the proportion of the gold in the gold have not been provided with a reliable analysis method and accurate data.

The gold in the Carlin type gold ore is mainly invisible gold (including sub-microscopic or nano-scale gold Au)0And lattice gold Au in a chemically bound state1+) In the form of (1) is assigned to the arsenic-rich annulus structure of the sub-outer layer of pyrite. The valence state of gold includes natural gold Au0And lattice gold Au in a chemically bound state1+. Due to the high XPS detection limit (about 0.1 at%), and the non-uniformity of gold distribution in the Carlin type gold ore sample, the research and application of the occurrence state of gold in the Carlin type gold ore are greatly limited. Furthermore, there is usually an oxide layer outside the gold-containing arsenic-rich pyrite annulus and gold-depleted pyrite (thickness on the order of microns), which will significantly affect the accuracy of the gold valence test. Therefore, developing a simple and efficient analysis method to research the occurrence state, especially valence state, of gold in the Carlin type gold ore sample is of great significance for finding out the occurrence state and enrichment and precipitation mechanism of gold in arsenious pyrite and disclosing the micro-cause mechanism of Carlin type gold ore, provides important basis for actual exploration, dressing and comprehensive utilization of the mineral resources, and simultaneously provides reference for analysis and characterization of the occurrence state of metal elements in sulfide minerals in other types of mineral deposits.

Disclosure of Invention

The invention aims to provide a characterization method of the occurrence state of gold in Carlin type gold ores, so as to solve the problem that the restriction mechanism of the valence state and the occurrence form of gold in arsenic-containing pyrite is uncertain.

In order to achieve the purpose, the invention adopts the following technical scheme: a characterization method of occurrence states of gold in Carlin type gold ores comprises the following steps: crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite by adopting HCl, washing the selected pyrite by using oxygen-free deionized water and absolute ethyl alcohol, drying the selected pyrite in a vacuum oven, and finally testing and analyzing the valence state of gold in the selected pyrite by using XPS.

Further, the solid-to-liquid ratio of the selected pyrite to the HCl solution is 1: 10-1: 100.

Further, the HCl concentration is 0.05-6 mol/L.

Further, the ultrasonic frequency is 20-100 Hz, the ultrasonic frequency is 1-10 times, the ultrasonic time is 10 min-6 h, and the ultrasonic water is washed and centrifuged for more than 1 time after each ultrasonic.

Furthermore, the ultrasonic etching temperature is 5-100℃.

Further, washing the substrate for more than 2 times by using absolute ethyl alcohol after the ultrasonic etching.

Further, the temperature of the washed sample is 5-80 ℃ during vacuum drying-Drying at a temperature of 2 hr or more.

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

the method for representing the valence state of the metal element in the sulfide by XPS is characterized after a Carlin type gold ore sample is treated by a simple etching method for the first time, and provides a new idea for representing the valence state of the metal element in the sulfide. The method has the advantages of easy repetition and the like, and the operation process is simple and convenient.

In the ore sample after concentration in the karlin type gold ore, an oxidation layer and gold-poor pyrite are generally arranged outside an arsenic-rich pyrite zone containing gold, which obviously influences the accuracy of gold valence state testing, so that the outer zone with low gold content needs to be removed by a specific method, but the oxidation reduction or corrosion of the gold-rich layer is not caused. Based on this, the idea of the present invention is to etch away the gold-free or low-gold-content endless belt as the outermost layer with a non-oxidizing acid to expose the gold-rich endless belt that can reach the detection limit of XPS, and then obtain information on the desired occurrence state of Au using XPS. The method can remove the gold-containing arsenic-rich pyrite zone, and the gold-poor pyrite (with the thickness of about micron order) with an oxide layer. The method has important significance for detecting the occurrence state and the mineralization mechanism of the gold in the Carlin type, provides important basis for the prediction, exploration and development, selection and metallurgy and comprehensive utilization of the mineralization model of the mineral resources, and also provides reference for the analysis and characterization of the occurrence state of the metal elements in the sulfide minerals in other types of mineral deposits. The characterization method provided by the invention has a certain application prospect in the aspect of analysis and characterization of occurrence states of metal elements in easily-oxidized natural and artificially-synthesized minerals.

Drawings

FIG. 1 is an XPS chart of example 1 of the present invention;

FIG. 2 is an XPS map of comparative example 1 of the present invention.

Detailed Description

The technical solution of the present invention is further described in detail by the following examples, which are illustrative but not limiting of the present invention.

Example 1

Crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite for 5 times at 45 ℃ and 40Hz by using 3mol/L HCl, wherein the solid-to-liquid ratio during each etching is 1: 50, performing ultrasonic treatment for 90min each time, then washing with deionized water and absolute ethyl alcohol for 3 times respectively, then drying in a vacuum oven at 30 ℃ for 2h, and then testing and analyzing the valence state of gold in the gold by XPS. The results are shown in FIG. 1.

The concentration of gold in this sample was about 0.24 at%, Au 4f7/2Peak separable fit is 85eV and 84.1eV, with the peak at 85eV being Au+And the peak at 84.1eV is Au0(Nanogold particles with a particle size of less than 10 nm), which indicates that gold in the Carlin-type gold ore sample is mainly Au+And Au0Two valence states exist in the arsenic-containing pyrite. By peak area estimation, Au+And Au0In a ratio of about 3: 2.

Example 2

Crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite for 10 times at the temperature of 30 ℃ and the frequency of 100Hz by using 3mol/L HCl, wherein the solid-to-liquid ratio of each etching is 1:10, performing ultrasonic treatment for 3 hours each time, then washing the mixture for 5 times by using deionized water and absolute ethyl alcohol respectively, then drying the mixture for 24 hours in a vacuum oven at 15 ℃, and then testing and analyzing the content and valence state of gold in the mixture by using XPS. The concentration of gold in this sample was about 0.18 at%, Au+And Au0In a ratio of about 1: 1.

Example 3

Crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite for 10 times at 100Hz at 100 ℃ by using 0.05mol/L HCl, wherein the solid-to-liquid ratio during each etching is 1:100 times of ultrasonic treatment for 6 hours, washing with deionized water and absolute ethyl alcohol for 3 times respectively, and then placing in a vacuum oven for 3 timesDrying at 0 deg.c for 8 hr, and XPS analysis to test the gold content and valence state. The concentration of gold in this sample was about 0.2 at%, Au+And Au0In a ratio of about 1: 1.

Example 4

Crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing 1-time ultrasonic etching on the selected pyrite at the temperature of 45 ℃ and at the frequency of 40Hz by using 6mol/L HCl, wherein the solid-to-liquid ratio of each etching is 1: 50, performing ultrasonic treatment for 90min each time, washing with deionized water and absolute ethyl alcohol for 3 times respectively, then drying in a vacuum oven at 30 ℃ for 8h, and then testing and analyzing the content and valence state of gold in the gold by XPS. The concentration of gold in this sample was about 0.03 at%, Au+And Au0In a ratio of about 1: 1.

Example 5

Crushing and floating crude ore samples of Carlin type gold ores to obtain selected pyrite, performing ultrasonic etching on the selected pyrite for 10 times at the temperature of 5 ℃ and the frequency of 20Hz by using 3mol/L HCl, wherein the solid-to-liquid ratio of each etching is 1:100, performing ultrasonic treatment for 10min each time, washing with deionized water and absolute ethyl alcohol for 1 time respectively, then drying in a vacuum oven at 80 ℃ for 1h, and then testing and analyzing the content and valence state of gold in the gold by XPS. The concentration of gold in this sample was about 0.02 at%, Au+And Au0In a ratio of about 1: 1.

Comparative example 1:

the method comprises the steps of crushing and floating crude ore samples of Carin type gold ores to obtain selected pyrite, directly performing characterization analysis on gold in the selected pyrite by XPS without acid etching (three lines are detection results of three different sample positions), and obtaining a result shown in figure 2. The characteristic peak of gold is not detected in the XPS spectrogram of the sample, which shows that the gold concentration on the surface of the sample without etching to remove the surface oxide layer and the gold-poor layer is lower than the detection limit of XPS, so that the content and valence of gold cannot be detected.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

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