Hydrothermal large-cavity high-temperature and high-pressure flow experiment device and method

Abstract

The invention discloses a hydrothermal large-cavity high-temperature and high-pressure flow experiment device. The device comprises a kettle body and kettle plugs; the kettle body is of a hexagonal structure; a cavity structure for containing a sample is arranged in the kettle body; the six side surfaces of the kettle body are connected with the six kettle plugs which are detachably sealed respectively; the three kettle plugs which are horizontally arranged are provided with optical windows; the rest three kettle plugs are provided with three electrode sensors, pH sensors, Eh sensors or oxygenchemistry sensors; the kettle plug at the upper end of the kettle body is provided with a high-pressure capillary outlet; the kettle plug at the lower end of the kettle body is provided with a high-pressure capillary inlet connected with a fluid pressurization system; a thermocouple is further mounted on the remaining kettle plug which is horizontally arranged; a heating device is arranged outside the kettle body; and an optical detection device is mounted in a position directly facing to the optical windows. The detachable kettle plug structure is adopted, so that without manufacturing high-pressure kettles with different sizes, the thickness of a solution in a sample cavity can be controlled according to the lengths of the kettle plugs by only manufacturing the kettle plugs with different lengths, and the technical problem that the thickness of the solution cannot be changed in the prior art is effectively solved.

Description

technical field [0001] The invention belongs to the technical field of high-temperature and high-pressure experimental devices, and in particular relates to a high-temperature and high-pressure flow experimental device and an experimental method in a hydrothermal large cavity. Background technique [0002] Pyrite is the most abundant metal sulfide on the surface and in the earth's interior. Its electrochemical corrosion in aqueous fluids is not only an important constraint mechanism for the circulation of sulfur and iron elements, but also other related elements on the surface, seabed and the earth's interior. . In mining production activities, although the use value of pyrite itself is low, it often appears with high-value minerals such as chalcopyrite, sphalerite, galena, gold, and silver. Electrochemical corrosion behavior in high-pressure hydrothermal fluids is often the determining factor for hydrometallurgical and beneficiation process conditions. Therefore, it is of...

AI Technical Summary

Problems solved by technology

[0004] (1) The pure electrochemical measurement method under high temperature and high pressure has the following disadvantages: the description of the reaction mechanism and the determination of kinetic parameters by the electrochemical method are based on current and potential measurements, such as according to current and scan speed, concentration, time or electrode rotation speed The functional relationship of a series of parameters, and then speculate on the reaction mechanism and determine the kinetic parameters. The main disadvantage is that this purely electrical measurement lacks the characteristics of the electrode reaction molecules, that is, the current only represents the total rate of all processes occurring on the electrode surface. , there is no useful direct information about the reaction products or intermediates. In addition, in the study of the electrode / electrolyte solution interface structure, the theoretical value is obtained from the measurement and calculation of the capacitance, and the information cannot be obtained from the molecular level.

Therefore, the three-electrode electrochemical measurement method under high temperature and pressure has certain limitations, for example: it does not have the ability to characterize specific molecules, and cannot adapt to the requirements of microscopic research. In complex multi-species systems, conventional electrochemical methods can only It can provide the sum of various microscopic information of the electrode reaction, but it is difficult to accurately identify the reactants, intermediates and products on the electrode and explain the reaction mechanism

The high-temperature and high-pressure flow reaction device designed by the predecessors cannot measure the solid products on the surface of the working electrode and the In situ measurement of material composition, electronic structure and local structure in solution

[0005] At present, the high-temperature and high-pressure devices that can perform in-situ measurements of synchrotron radiation X-ray spectroscopy cannot use electrochemical methods to study the experimental system, and there are the following problems. When the technology is combined, there are some shortcomings: ①The density of diamond is relatively high (3.52g / cm3), and it absorbs heavily the X-rays with energy lower than 10keV. When the 2.4mm diamond anvil is used, the luminous flux will be reduced by 2 orders of magnitude; ②The diamond anvil is a single crystal, and when the absorption spectrum is measured in the transmission mode, a diamond diffraction peak will be generated, which seriously interferes with the quality of the absorption spectrum of the test sample

In addition, it is very difficult for HDAC to independently control the two variables of temperature and pressure, and the size of the sample chamber is generally small (~0.2mm 3 ), it is also very difficult to further increase the volume of the sample chamber, so it is difficult to realize the in-situ monitoring of the fluid properties, that is, it is impossible to fully reveal the internal relations such as the occurrence form of the ore-forming elements and the fluid properties under different temperatures, pressures, and flow rates;

[0006] The synchrotron radiation technology combined with hydrothermal large-cavity high-temperature and high-pressure devices is relatively simple. At present, there are only reports on the combination of synchrotron radiation X-ray absorption spectroscopy, synchrotron radiation X-ray absorption spectroscopy and X-ray fluorescence spectroscopy. It is mainly used to measure the electronic structure and local structure of substances in fluids. It is difficult to measure solid substances, and the identification of solid surface products in the process of water-fluid-solid interaction is particularly important, so more testing techniques are required. For more information on solid-liquid reaction processes

[0007] (2) In the process of measuring the X-ray absorption spectrum, due to the difference between the solution concentration and the X-ray intensity, the measurement process may need to measure solutions of different thicknesses, so it is necessary to make pressure vessels with different inner diameters, and the cost is relatively high;

Images