A microcalorimetric method for studying sulfide galvanic action

Abstract

The application discloses a microcalorimetric testing method for studying sulfide galvanic effect, which comprises the following steps: (1) preparation before testing; (2) testing by using a microcalorimetric testing controller. The application can understand the dissolution characteristics between different sulfides and collectors and the influence of the existence of galvanic effect between two sulfides on the dissolution characteristics between mixed minerals and collectors, and provides a thermodynamic basis for the flotation separation of sulfides.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, specifically a microcalorimetric method for studying the galvanic effect in sulfide minerals. Background Technology

[0002] In the selective leaching process of sulfide mineral systems, the galvanic interaction generated by the contact between sulfide minerals can inhibit the leaching of certain sulfides by forming galvanic cells between conductive minerals. To accurately verify galvanic interactions, both the thermodynamics and kinetics of the galvanic reaction process should be considered. In fact, the combination of microcalorimetry with various analytical techniques is very useful in many research applications. Changes in heat can always be measured using calorimetry without being affected by any process interference. In the absence of more specific analytical information, non-specific calorimetric signals from complex reaction systems are often difficult to interpret at the molecular level. Calorimetric signals provide a general description of complex processes, which specific analytical signals rarely provide. The application of traditional calorimeters makes the determination of solution thermodynamic parameters highly reliable and repeatable. However, due to large sample consumption, insufficient sensitivity, and long measurement time, they are not practical for determining enzyme reaction kinetics or studying other biological reactions. Further improving sensitivity would require a smaller calorimeter. Based on advancements in calorimetry and microelectromechanical systems (MEMS) technology, micro calorimeters have been proposed and improved. These calorimeters are used to measure thermal changes in the microwatt range under essentially isothermal conditions. Micro calorimeters can solve the problems encountered by traditional calorimeters and are now widely used to measure and characterize thermal changes in dissolution, phase transitions, resolving mixtures, and chemical / biochemical reactions.

[0003] Galvanic interactions occur at the contact surfaces of conductive minerals, and surface dissolution is an important indicator of mineral surface properties. Microcalorimetry can measure the thermal effects during processes such as dissolution, adsorption, and desorption between substances, thus becoming an important research method for studying surface interfacial reactions in minerals. However, there are currently no reports on using microcalorimetry to study galvanic interactions between sulfide minerals. Summary of the Invention

[0004] This invention provides a microcalorimetric method for studying the galvanic effect of sulfide minerals in flotation systems. The dissolution characteristics between different sulfide minerals and collectors were tested, as well as the influence of the galvanic effect between two sulfide minerals on the dissolution characteristics between the mixed minerals and the collector. This allows for a direct study of the microcalorimetric dissolution characteristics of sulfide minerals after galvanic action under the action of butyl xanthate or butylammonium black collectors, providing a thermodynamic basis for the flotation separation of sulfide minerals.

[0005] This invention achieves the above objective through the following technical solution: a microcalorimetric testing method for studying the galvanic effect in sulfide minerals, comprising the following steps:

[0006] (1) Preparation before the test

[0007] Weigh 100 mg of mineral sample with a purity of 95% or higher and place it in the outer glass tube of the microcalorimetric test sample cell. Then, measure 1 mL of the collector butyl xanthate or butylammonium black and place it in the inner glass tube. Similarly, measure 1 mL of the collector butyl xanthate or butylammonium black and place it in the inner glass tube of the reference cell. Control the reaction temperature at 298.15 K and the pH value at 7.

[0008] (2) Testing was conducted using a micro-calorimeter.

[0009] Before the microcalorimetry experiment, temperature control is initiated to ensure the tube temperature matches the set temperature. Baseline measurement and calibration are then performed. Once the baseline stabilizes, the calorimetry program begins. After the reaction is complete, the measured result—the heat of reaction Q—displayed on the computer is recorded. The calorimetry program is then closed, and the samples from the sample and reference cells are removed, replaced, and placed back into the calorimetry cylinder. Once the baseline stabilizes again, the next set of microcalorimetry experiments can be conducted. The difference in calorimetry between the sample and reference cells is the heat of reaction in the microcalorimetry experiment, calculated using the following formula:

[0010] Q = H·A

[0011] In the formula: A is the area of ​​the micro-thermodynamic curve; H is the calorific coefficient of the instrument, which is calibrated by the Joule effect or standard substances.

[0012] The mineral sample mentioned in step (1) is pyrrhotite, pyrrhotite, or a mixture of pyrrhotite and pyrrhotite.

[0013] The particle size of the mineral sample in step (1) is 45-74 μm.

[0014] The concentration of the collector butylammonium black powder or butyl xanthate in step (2) is 20 × 10⁻⁶. -5 mol / L.

[0015] The mineral samples in the sample pool in step (2) are 50 mg each of pyrrhotite and brittle stibnite with a particle size of 45-74 μm, which are uniformly mixed.

[0016] The collector in the inner glass tube of the reference cell and the sample cell in step (2) is the same, but there is no sample in the outer glass tube of the reference cell.

[0017] The advantages of this invention are:

[0018] This invention uses microcalorimetry to study the dissolution characteristics of different sulfide minerals with collectors, as well as the influence of galvanic reaction between two sulfide minerals on the dissolution characteristics of mixed minerals with collectors. It can directly study the microcalorimetric dissolution characteristics of sulfide minerals under the action of butyl xanthate or butylammonium black collectors after galvanic reaction. This invention fills the research gap on the influence of mineral dissolution properties under galvanic reaction on flotation results and provides a thermodynamic basis for the flotation separation of sulfide minerals. Attached Figure Description

[0019] Figure 1 This is an experimental schematic diagram of the microcalorimetric testing method for the galvanic action of sulfide minerals described in this invention.

[0020] Figure 2 This is a schematic diagram of the internal structure of the sample cell (a) and reference cell (b) of the microcalorimetric testing method for the galvanic action of sulfide minerals described in this invention.

[0021] Figure 3 The trace thermodynamic curves of the brittle stibnite described in this invention in butyl xanthate and butyl ammonium black powder before galvanic reaction are shown.

[0022] Figure 4 These are trace thermodynamic curves of pyrrhotite in butyl xanthate and butylammonium black powder before galvanic action, as described in this invention.

[0023] Figure 5 The micro-thermodynamic curves of the mixed minerals of brittle stibnite and pyrrhotite described in this invention after galvanic reaction in butyl xanthate and butylammonium black resin, respectively. The collector concentration is 20 × 10⁻⁶. -5 mol / L,

[0024] The figures are labeled as follows: 1. Micro-thermodynamic curve of the mixed mineral of stibnite and pyrrhotite under galvanic action and butyl xanthate action; 2. Micro-thermodynamic curve of the mixed mineral of stibnite and pyrrhotite under galvanic action and butyl xanthate action. Detailed Implementation

[0025] The technical solution of the present invention will be further described below through embodiments.

[0026] Example 1

[0027] An example of the microcalorimetric testing method for studying the galvanic effect in sulfide ores described in this invention is to test the microcalorimetric analysis of brittle stibnite under different collectors (using butylammonium black powder and butyl xanthate as examples) when galvanic effect has not occurred. The method includes the following steps:

[0028] (1) Inside the sample cell: Measure 1 mL of sample with a concentration of 20×10 -5The mol / L butylammonium black reagent was placed in the inner glass tube, and the outer glass tube contained the experimental sample, which was brittle stibnite with a particle size of 45-74 μm. The reaction temperature was controlled at 298.15 K.

[0029] (2) Inside the reference cell: 1 ml of a concentration of 20 × 10⁻⁶ was measured. -5 The mol / L butylammonium black reagent was placed in the inner glass tube, and there was no sample in the outer glass tube. The reaction temperature was controlled at 298.15 K.

[0030] (3) Place the samples from steps (1) and (2) into the metal sleeve and place them in the microcalorimeter. After the reaction begins, the heat flow passes through the converter (Analog to Digital converter, i.e., A / D conversion) in the microcalorimeter. The thermal effect is converted into an electrical effect and transmitted to the computer recording software at the far right. The microcalorimeter curve is displayed synchronously. Each point represents the reaction heat measured in one second. The thermal spectrum curve changes with time. When the curve gradually returns to the horizontal, it means that the reaction is stabilizing or the reaction is over. Temperature control is started before the microcalorimeter experiment to keep the temperature inside the tube consistent with the set temperature. Then, the baseline is measured and corrected. When the measurement baseline is kept stable (represented as a smooth horizontal straight line on the computer monitor), the calorimeter program can be started. After the reaction is over, the reaction heat value Q obtained from the computer is recorded. The microcalorimeter test data of brittle antimony lead ore under the action of butylammonium black is 24.3 mJ. Then the calorimeter program can be turned off.

[0031] (4) Replace the inner glass tube of the sample cell with 100 mg of brittle stibnite with a particle size between 45 and 74 μm. Measure the butyl xanthate placed in the outer glass tube, keeping the amount in (1) unchanged. Repeat steps (1) to (3) above. The microcalorimetric test data of brittle stibnite under the action of butyl xanthate is measured to be 45.7 mJ. The microcalorimetric difference between the sample cell and the reference cell is the heat of reaction in the microcalorimetric experiment, and its calculation formula is as follows:

[0032] Q = H·A

[0033] In the formula: A is the area of ​​the micro-thermodynamic curve; H is the calorific coefficient of the instrument, which is calibrated by the Joule effect or standard substances.

[0034] Example 2

[0035] This embodiment is another example of the microcalorimetric testing method for galvanic action in sulfide ores described in this invention. Taking the microcalorimetric testing of pyrrhotite without galvanic action under different collectors (butyl ammonium xanthate and butyl xanthate as examples) as an example, it includes the following steps:

[0036] (1) Inside the sample cell: measure a concentration of 20 × 10⁻⁶. -51 mL of mol / L butylammonium black powder was placed in an inner glass tube, and the outer glass tube contained the experimental sample, which was 100 mg of pyrrhotite with a particle size between 45 and 74 μm. The reaction temperature was controlled at 298.15 K.

[0037] (2) Inside the reference cell: 1 ml of a concentration of 20 × 10⁻⁶ was measured. -5 The mol / L butylammonium black reagent was placed in the inner glass tube, and there was no sample in the outer glass tube. The reaction temperature was controlled at 298.15 K.

[0038] (3) Place the samples from steps (1) and (2) into the metal sleeve and place them in the micro calorimeter. After the reaction begins, the heat flow passes through the converter (Analog to Digital converter, i.e., A / D conversion) in the micro calorimeter. The thermal effect is converted into an electrical effect and transmitted to the computer recording software at the far right. The micro calorimeter curve is displayed synchronously. Each point represents the reaction heat measured in one second. The thermal spectrum curve changes with time. When the curve gradually returns to the horizontal, it means that the reaction is stabilizing or the reaction is over. Temperature control is started before the micro calorimeter experiment to keep the temperature inside the tube consistent with the set temperature. The baseline is measured and corrected. When the measurement baseline is kept in a stable state, the stable state means that it is reflected as a smooth horizontal straight line on the computer screen. The calorimeter program can be started. After the reaction is over, the reaction heat value Q obtained from the computer is recorded. The micro calorimeter test data of pyrrhotite under the action of butylammonium black is -20.1mJ. Then the calorimeter program can be turned off.

[0039] (4) Refill the outer glass tube of the sample cell with 1 ml of 20×10⁻⁶ solution. -5 The glass inner tube was filled with 100 mg of pyrrhotite with a particle size between 45 and 74 μm, and the process was repeated as in step (1). The microcalorimetric test data of pyrrhotite under the action of butyl xanthate was -24.7 mJ. The microcalorimetric difference between the sample cell and the reference cell is the reaction heat of the microcalorimetric experiment, and its calculation formula is as follows:

[0040] Q = H·A

[0041] In the formula: A is the area of ​​the micro-thermodynamic curve; H is the calorific coefficient of the instrument, which is calibrated by the Joule effect or standard substances.

[0042] Example 3

[0043] This embodiment describes the microcalorimetric testing method for the galvanic reaction of sulfide ores according to the present invention. Taking the microcalorimetric testing of pyrrhotite and brittle stibnite after galvanic reaction under different collectors (butyl ammonium xanthate and butyl xanthate as examples) as an example, it includes the following steps:

[0044] (1) Inside the sample cell: measure a concentration of 20 × 10⁻⁶. -5 1 mL of mol / L butylammonium black powder was placed in the inner glass tube. 50 mg of pyrrhotite with a particle size of 45-74 μm and 50 mg of brittle stibnite with a particle size of 45-74 μm were weighed and mixed evenly together and placed in the outer glass tube. The reaction temperature was controlled at 298.15 K.

[0045] (2) Inside the reference cell: Measure 1 mL of a concentration of 20×10 -5 A mol / L butylammonium black powder A was placed in an inner glass tube, while the outer glass tube was empty. The reaction temperature was controlled at 298.15 K.

[0046] (3) Place the above steps (1) and (2) into the sleeve and place it in the micro calorimeter. After the reaction starts, the heat flow passes through the converter (Analog to Digital converter, i.e., A / D conversion) in the micro calorimeter. The thermal effect is converted into an electrical effect and transmitted to the computer recording software at the far right. The micro calorimeter curve is displayed synchronously. Each point represents the reaction heat measured in one second. The thermal spectrum curve changes with time. When the curve gradually returns to the horizontal, it means that the reaction is stabilizing or the reaction is over. Temperature control is started before the micro calorimeter experiment to keep the temperature inside the tube consistent with the set temperature. Then, the baseline is measured and corrected. When the measurement baseline is kept stable (represented as a smooth horizontal straight line on the computer monitor), the calorimeter program can be started. After the reaction is over, the reaction heat value Q obtained from the computer is recorded. The micro calorimeter test data of the mixed mineral of pyrrhotite and brittle stibnite under the action of butylammonium black after galvanic action is 23.8 mJ. Then the calorimeter program can be turned off.

[0047] (4) Refill the outer glass tube of the sample cell with 1 mL of 20×10⁻⁶ solution. -5 The glass inner tube was filled with butyl xanthate at mol / L. The same mixture of pyrrhotite (45–74 μm) and basaltite (45–74 μm) was added back into the glass tube, and steps (1) to (3) were repeated. The microcalorimetric test data under the action of butyl xanthate after galvanic reaction of the pyrrhotite and basaltite mixture was found to be 59.1 mJ. The microcalorimetric difference between the sample cell and the reference cell is the heat of reaction in the microcalorimetric experiment, and its calculation formula is as follows:

[0048] Q = H·A

[0049] In the formula: A is the area of ​​the micro-thermodynamic curve; H is the calorific coefficient of the instrument, which is calibrated by the Joule effect or standard substances.

Claims

1. A microcalorimetric method for studying the galvanic effect in sulfide minerals, characterized in that, Includes the following steps: (1) Preparation before the test Weigh 100 mg of mineral sample with a purity of 95% or higher and place it in the outer glass tube of the microcalorimetric test sample cell. Then, measure 1 mL of the collector butyl xanthate or butylammonium black and place it in the inner glass tube. Similarly, measure 1 mL of the collector butyl xanthate or butylammonium black and place it in the inner glass tube of the reference cell. Control the reaction temperature at 298.15 K and the pH value at 7. (2) Testing was conducted using a micro-calorimeter. Before the microcalorimetry experiment, temperature control is initiated to ensure the tube temperature matches the set temperature. Baseline measurement and calibration are then performed. Once the baseline remains stable, the calorimetry program begins. After the reaction is complete, the measurement result—the heat of reaction Q—displayed on the computer is recorded. The calorimetry program is then closed, and the samples from the sample and reference cells are removed, replaced, and placed back into the calorimetry cylinder. Once the baseline returns to a stable state, the next set of microcalorimetry experiments can be conducted. The difference in calorimetry between the sample and reference cells is the heat of reaction in the microcalorimetry experiment, calculated using the following formula: Q = H·A In the formula: A is the area of ​​the micro-thermodynamic curve; H is the calorific coefficient of the instrument, which is calibrated by the Joule effect or standard substances.

2. The microcalorimetric testing method for studying the galvanic effect in sulfide minerals according to claim 1, characterized in that, The mineral sample mentioned in step (1) is pyrrhotite, pyrrhotite, or a mixture of pyrrhotite and pyrrhotite.

3. The microcalorimetric testing method for studying the galvanic effect in sulfide minerals according to claim 1, characterized in that, The particle size of the mineral sample in step (1) is 45-74 μm.

4. The microcalorimetric testing method for studying the galvanic effect in sulfide minerals according to claim 1, characterized in that, The concentration of the collector butylammonium black powder or butyl xanthate in step (2) is 20 × 10⁻⁶. -5 mol / L.

5. The microcalorimetric testing method for studying the galvanic effect in sulfide minerals according to claim 1, characterized in that, The sample pool contains 50 mg of pyrrhotite and brittle stibnite, each with a particle size of 45–74 μm, uniformly mixed.

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