Multi-flame monitoring system of flash smelting furnace for processing metal sulfide concentrates and minerals

Abstract

The invention discloses a multi-flame monitoring system of a flash smelting furnace for processing metal sulfide concentrate and minerals, the system at least comprises a set of photoelectric probe, and the photoelectric probe comprises a visible light sensor, an infrared light sensor and a lens for capturing RGB (Red, Green, Blue) images; the S-shaped thermocouple is used for monitoring the furnace temperature; the gas analyzer is used for reading an oxygen signal; a protection and cooling system of the probe; the processing system and the control module are matched with distributed control, and the photoelectric probe, the S-shaped thermocouple for monitoring the furnace temperature, the gas analyzer for reading oxygen signals and the probe protecting and cooling system are all connected with the processing system and the control module. On-line and real-time production operation data are generated through RGB image and spectral analysis, S-type thermocouple temperature measurement, oxygen content analysis and collected furnace condition information for software processing, quality indexes of metallurgical reaction in the furnace are provided in combination with a comparison metallurgical model, the oxygen-material ratio and the oxygen-enriched concentration are suggested to be adjusted, and the production process is optimized and stabilized.

Description

Technical Field

[0001] The present invention relates to the technical field of pyrometallurgy, and particularly to a multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals. Background Art

[0002] The production of metals and alloys belongs to heavy industry and is generally divided into two categories: the ferrous metal industry related to the steel industry and the non-ferrous metal industry including the production of various base metals. The main non-ferrous metals are copper, nickel, zinc, and lead. For these two types of metal industries, production is basically completed by a pyrometallurgical process in which chemical conversion occurs under high-temperature conditions.

[0003] For the production of both types of metals, the basic physical and chemical principles in the process concept are the same. Similarly, there are obvious similarities between the production processes of steel and the production systems of base metals such as copper, nickel, zinc, and lead. However, an analysis of production standards, process indicators, and efficiency shows that there are obvious differences between these two types. Currently, the processes and technologies in the steel industry are much more efficient than the pyrometallurgy of non-ferrous metals. These comparable semi-quantitative indicators include product diversity with the same facilities and operators, the consumption of refractory materials, and process control and instrumentation systems.

[0004] The process control in the steel industry is based on a deep understanding of the physical and chemistry at different stages of the production process, which strongly guarantees the production of various products. In addition, instruments and prediction models are used to efficiently control the production process with minimal interference from human factors. In contrast, in the pyrometallurgy process of non-ferrous metals, especially in the process of extracting crude metals from sulfide ores and concentrate powders, almost no instruments are used for process monitoring and control, especially on-line and / or real-time detection, resulting in a lack of basic data to support decision-making at the production site. Therefore, operation control relies on macroscopic mass and energy balances, and process dynamics control largely depends on the experience of operators.

[0005] The extraction of copper from sulfide concentrates can be divided into several stages, in which sulfur and iron are selectively oxidized and separated from copper sulfide concentrates to produce metallic copper as the final product. Copper concentrates can be represented as a mixture of copper, iron, and sulfur, which also contains various oxides considered as gangue, which are inert substances in the smelting process.

[0006] The first stage is the smelting of copper concentrates to produce a molten phase composed of Cu2S and FeS. The chemical reactions representing this stage are as follows:

[0007]

[0008] The above equation represents the partial oxidation of copper concentrate (Cu, Fe, S) to form FeO, which combines with SiO2 to form slag. Due to the density difference, this slag separates from the main product and forms a separate oxide phase, leaving a liquid mixture melt of Cu2S and FeS, known as matte or matte phase. The copper content at this stage can be controlled by appropriately adding a mixture of air and oxygen, represented by O2(N2)(g) in reaction (1), and part of the S is oxidized to form SO2(g).

[0009] The matte produced in the smelting stage enters the subsequent process sections with similar characteristics for treatment, known as converting. In this stage, the oxidation reaction continues to oxidize all the remaining S and Fe to produce metallic Cu, and then anode copper is produced through pyrometallurgical refining, and the final product with a purity exceeding 99.95% is produced through electrolytic refining, known as electrolytic copper. The converting process can be represented by the following scheme:

[0010]

[0011] For the production of crude nickel, the process selection varies depending on the concentrate. For sulfide nickel concentrate, the process is similar to that of Cu, producing matte composed of NiS and FeS, which is oxidized and enriched to obtain Ni3S2, and further oxidizing Fe and S to finally obtain metallic Ni.

[0012] As seen above, the chemical conversion process is oxidation, which has obvious similarities with combustion reactions: in this case, the fuel is Fe and S present in the concentrate or mineral, and the oxidant is oxygen.

[0013] There are various types of processes in the smelting stage, mainly including two categories: flash smelting process and bath smelting process. The operation control of these reactors is basically based on the macroscopic mass and energy balance to determine the amount of oxygen to be added to the reactor, realizing the oxidation of Fe and S and the set Cu content in the matte or matte phase. There is a lack of specific tools in the operation process to record the available information describing the physical and chemical reactions (reactions 1 and 2) in the furnace, and the process reactions cannot be precisely controlled. In fact, it cannot always be guaranteed to manipulate the oxygen distribution according to the design of reaction (1). If the oxygen does not react with Fe and S in the copper concentrate in a set ratio, excessive oxidation of the slag will occur, especially for flash and / or instantaneous smelting furnaces, resulting in a large amount of dust. This leads to 1) affecting the overall copper recovery rate due to excessive oxidation of the slag, and 2) affecting the reactor operation time because more dust (mainly partially or unburned concentrate particles) causes coking in the flue gas system and requires shutdown for removal.

[0014] So far, no operation plan has been able to ensure good control over the oxidation process of sulfide minerals, mainly because of the lack of appropriate process monitoring instruments. For these smelting processes, it is crucial to have an on-line real-time monitoring system, which can provide a basis for adjusting operation parameters and achieve sufficient operation control, thus avoiding the above problems.

[0015] The application of spectral information in the production of non-ferrous metal crude products is almost blank. Until the last decade, some studies have used the luminescence of the PS converter flame as an information source for identifying certain process parameters, such as the end point of slag formation, on-line control of the iron content in matte, and slag quality control (Prietl et al., 2004). In these schemes, proprietary technologies have been developed to determine the end point of the first conversion stage, and the system application process control has stability. The only commercial application of an instrument specifically designed based on optoelectronics for non-ferrous metal pyrometallurgical process control is introduced. This device is the OPC system (Optical Production Control), sold by Semtech Corporation of Sweden.

[0016] Directly studying the spectral information generated by high-temperature flames can provide a deeper understanding of the smelting process by non-contact determination of the reaction temperature and observation of the types and concentrations of the main reaction substances. This concept has been successfully applied to the combustion of liquids or gases (Romero et al., 2005) and the combustion of pyrotechnic mixtures (Gillard et al., 2002a; Gillard et al., 2002b; Weiser and Esenreich, 2005). In these applications, the information provided at a scanning speed of several hundred spectra per second has been sufficient to study the flame structure, the reaction process of most pyrotechnic mixtures, the movement and combustion of individual particles, the ignition process of powders, the propagation of gas explosions, and on-site observation of reactions in a closed combustion chamber through optical fibers (Weiser and Esenreich, 2005).

[0017] Most of the proposed applications related to the concept of spectral measurements are applied to pyrometallurgical processes of non-ferrous metals, considering the design of a two-color optical pyrometer to measure the temperature of particles and reaction systems. However, except for the specific case of OPC in monitoring and control systems, this information has not been integrated. There is no complete spectral radiation measurement report on the emission of particles or particle populations, such as during the combustion of sulfide concentrates and / or minerals, from which information on their chemical and physicochemical combustion processes can be inferred. Jorgensen and Zuiderwyk (1985) proposed a two-color pyrometer for measuring the temperature of individual moving particles in the range of 1473 - 2773 K, choosing wavelengths of 545 nm and 581 nm. Tuffrey et al. (1995) proposed a two-wavelength pyrometer based on radiation at 710 nm and 810 nm to measure the particle combustion temperature. Subsequently, Laurila et al. (2005) proposed a two-wavelength pyrometer based on 997.5 nm and 1608 nm to measure the temperature of burning particles. This system can also measure particle size using an optical arrangement in view of the center of the optical fiber and lens. The differences in using different spectral bands are because measuring temperature based on spectral information depends on many factors, such as the emissivity of the material, and additional radiation and spectral band absorption due to the presence of other gas species in the pyrometer's field of view.

[0018] Research on the combustion of sulfides related to non-ferrous metal production has been entirely based on laboratory setups, using different vertical reactors, mainly laminar flow reactors (drippers) to maintain a controlled environment. Similar reactors and measurement equipment have been used to study the combustion of carbon particles (Bejarano and Levendis, 2007; Bejarano and Levendis, 2008), and the combustion of sulfide systems that have been carried out has been comprehensively described in accordance with the research methods of fossil fuel combustion. Early works analyzing the basic physicochemical phenomena of different sulfide particles (Sohn et al., 1985 - 1995; Jorgensen et al., 1975 - 1985; Brimacombe et al., 1990) described the flash combustion phenomenon of individual particles, determining the ignition temperature and multiphase conversion mechanism between the mineral particles, gases, and molten phases generated during the combustion process. From the same perspective, these studies have extended the basic understanding of flash conversion ( (J.et al., 1999; EJ Peuranienmi et al., 1999). At present, all the work carried out in this field can well understand the physical and chemical transformation of specific and individual mineral particles during combustion, but the behavior of a group of particles has not been analyzed to extend this description to the flame during the combustion process. In the case of flash smelting, the smelting is determined by the reactions in the flame, and its study from the perspective of combustion phenomena has only been carried out by Caffery (2002) in a pure academic framework.

[0019] We can draw the conclusion that although an accurate physical and chemical description of the combustion of sulfide particles can be made, the description of the whole phenomenon in the flame has not been solved, just as it may be done in the combustion of coal and natural gas. Considering the speed of individual phenomena, spectral radiation measurement and analysis are almost the only way to obtain quantitative on-line information on the physical and chemical phenomena of particle groups during combustion.

[0020] The aforementioned OPC system is based on US Patent 5,125,963, which allows the identification of the progress of the sulfide oxidation reaction during the production of blister copper. This system has been in market application for more than 20 years, mainly by analyzing the emission spectra during the conversion of copper slag and matte in a PS converter to monitor pyrometallurgical variables. This radiation shows a series of distinct colors in the spectrum, which can be associated with certain components present, and these components can be used for pyrometallurgical control of the conversion process. This system is based on a spectrophotometer and optical devices and can be used in a harsh environment. The spectrophotometer mainly identifies a substance (lead oxide) in the gas, and its concentration is related to the progress of the bath process.

[0021] So far, there has been no report in scientific literature or patents on monitoring equipment for metal sulfide smelting processes developed for the purpose of smelting operation control, and its control system is usually completely based on static mass and energy balances. In addition, the smelting quality is visually evaluated by the operator through limited peeping at the flame, and this method is non-standardized because it is based on the operator's experience. Based on these backgrounds, it is necessary to develop technologies capable of monitoring and controlling the pyrometallurgical processes of non-ferrous metals. Summary of the Invention

[0022] The present invention provides a multi-flame monitoring system for a flash smelting furnace or an instantaneous furnace for treating metal sulfide concentrates, which is particularly suitable for monitoring Outokumpu furnaces for extracting Cu, Ni, and Pb, Inco furnaces for extracting Ni, and other various smelting furnaces for extracting metals from metal sulfide ores using oxidation processes. The process monitoring instrument provided by the present invention can accurately monitor and control the pyrometallurgical processes of non-ferrous metals.

[0023] The present invention provides the following technical solutions:

[0024] A multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals, characterized in that: the system includes at least one set of optoelectronic probes, and the optoelectronic probes include visible light, infrared sensors and a lens for capturing RGB images; an S-type thermocouple for monitoring the furnace temperature; a gas analyzer for reading oxygen signals; a protection and cooling system for the probes; a processing system and a control module for distributed control, and the optoelectronic probes, the S-type thermocouple for monitoring the furnace temperature, the gas analyzer for reading oxygen signals, and the protection and cooling system for the probes are all connected to the processing system and the control module;

[0025] The optoelectronic probes can be placed at appropriate positions and at any angle to receive the nozzle flame signals to monitor all or part of the development process of the flame;

[0026] The gas analyzer measures the oxygen signal in the gas entering the gas purification stage from the gas transmission system of the flash smelting furnace in a standard manner;

[0027] The cooling system protects and cools the optoelectronic probes; the optoelectronic probes with a diameter of 75 mm - 1100 mm are installed in a set of cooling jackets, and the coolant in the cooling jackets can be air or water;

[0028] The protection system of the optoelectronic probes includes a set of nitrogen injection jackets for protecting the photodetectors and lenses of the optoelectronic probes;

[0029] The optoelectronic probes are equipped with a thermocouple sleeve, and an S-type thermocouple is installed inside to detect the temperature at the position where the optoelectronic probes are located;

[0030] The processing system and the control module generate on-line and real-time signals to adjust the oxygen-to-feed ratio at the nozzle and the oxygen concentration in the enriched oxygen air; the processing system and the control module include a data acquisition part and a processing software part, and the measuring equipment used in the data acquisition part communicates with the processing software part through a wired communication line;

[0031] The data collected by the optoelectronic probes is combined with the measured oxygen data to generate the oxygen-to-feed ratio in the optimal nozzle area;

[0032] The multi-flame monitoring system is adapted to the Outokumpu flash smelting furnace for copper, nickel and lead;

[0033] The multi-flame monitoring system is adapted to the Inco flash smelting furnace for nickel;

[0034] The processing software part integrates statistical and metallurgical model algorithms specific to each component, provides indicators capable of diagnosing combustion quality, and through the reaction scheme Modify the operation of the equipment according to the oxygen efficiency and performance, and adjust the solid / oxygen ratio of the burner and the percentage of oxygen in the oxygen-enriched air; the algorithm adopted by the processing software part determines the flame temperature by spectral thermal analysis according to the radiation curve characteristics of metal sulfides and concentrates under high-temperature furnace ore.

[0035] Preferably, the photoelectric probe is located anywhere where any viewing angle is allowed.

[0036] Preferably, the signals measured by the photoelectric probe are used to calculate the flame temperature and the reactivity level of the oxidation reaction; the spectral information provided by the photoelectric probe is combined with the O2(g) analysis information to establish a control index for optimizing the solid / oxygen ratio entering the reactor.

[0037] Preferably, both the spectral measurement sensor S1 and the spectral measurement sensor S2 are of the photodetector type.

[0038] Preferably, the multi-flame monitoring system performs quality determination by using evaluation parameters quantified as radiation indexes by using optoelectronic devices. The parameters at least include the solid feed rate, the total O2(g) flow control, and the percentage of O2(g) used as an oxidant; the probe diameter in the multi-flame monitoring system does not exceed 5 cm, and the multi-flame monitoring system adopts a non-invasive measurement method to monitor the source of the smelting process.

[0039] Preferably, the multi-flame monitoring system utilizes RGB images and spectral analysis in the visible light and near-infrared ranges, which is realized by a spectrophotometer from the visible light to the near-infrared spectral range. The flame wavelength range determined by the multi-flame monitoring system is between 500 nm and 900 nm, where the emissivity of the molten phase is constant above its melting temperature and the temperature exceeds 1600 °C.

[0040] Preferably, the intensity level measured by the multi-flame monitoring system calculates the reactivity degree of the smelting reaction through an appropriate metallurgical model calibrated for a specific furnace, quantitatively determines the effective conditions for appropriate combustion quality, generates operation monitoring indexes according to the mass balance and chemical properties of the molten phase, combines the equipment signals of appropriate smelting result conditions to generate reference parameters, is used for real-time comparison of the signals obtained from this system with the reference values, and defines an online alarm when the obtained values deviate from the reference values.

[0041] Preferably, the furnaces adapted by the multi-flame monitoring system include Outokumpu flash and / or flash smelting furnaces for copper, nickel, and lead smelting, inco-type flash and / or flash smelting furnaces for nickel smelting, and flash and / or flash smelting furnaces for processing sulfide minerals and / or concentrates in the production of metal concentrates.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The multi-flame monitoring system for flash smelting furnaces used to process metal sulfide concentrates and minerals combines control items based on radiation variables (specific relationships of the measured radiation intensity as a function of wavelength in the visible and near-infrared ranges), optics, and chemistry. It can be proportionally optimized according to the requirements and particularities of the minerals or concentrates being processed, and concretize software parameters that interact with traditional equipment control items.

[0044] 2. The multi-flame monitoring system for flash smelting furnaces used to process metal sulfide concentrates and minerals generates reference parameters by combining equipment signals under appropriate smelting result conditions. It can be used to compare the signals obtained from the system with the reference values in real time, define online alarms when the obtained values deviate from the reference values, optimize the production process, minimize the dust generated by unburned particles, and control the chemical quality of the smelting products: the stability of the copper content in matte or matte phases, and minimize the excessive oxidation of slag.

[0045] 3. The multi-flame monitoring system for flash smelting furnaces used to process metal sulfide concentrates and minerals adopts a non-invasive measurement method. The measurement behavior does not change the operation of the furnace. The proposed sensor design is relatively simple, with low maintenance costs. It monitors the source of the combustion process, conducts online monitoring and control, and can respond more quickly to the monitoring and control stages; minimizes and almost eliminates equipment idle time, reduces over-oxidized slag, increases the recovery rate of the processed metal, continuously strengthens the stability of the processed metal content in the metal phase, and has a positive impact on subsequent stages. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the furnace body in Embodiment 1 of the present invention;

[0047] Figure 2 Schematic diagram of the details of the furnace chamber and monitoring system in Embodiment 1 of the present invention;

[0048] Figure 3 Schematic diagram of the radiation intensity of concentrate A under different oxygen levels in Embodiment 1 of the present invention;

[0049] Figure 4 Schematic diagram of the radiation intensity of concentrate B under different oxygen levels in Embodiment 1 of the present invention;

[0050] Figure 5 Schematic diagram of the radiation intensity of concentrate C under different oxygen levels in Embodiment 1 of the present invention;

[0051] Figure 6 Schematic diagram of a simple application solution during industrial operation in Embodiment 2 of the present invention;

[0052] Figure 7 Schematic diagram of the corresponding radiation intensity during operation under different working conditions in Embodiment 2 of the present invention;

[0053] Figure 8 Schematic diagram of the integration of system components of the present invention;

[0054] Figure 9 Schematic diagram of the sensor distribution in the probe to be introduced into the furnace in Embodiment 2 of the present invention.

[0055] In the figure: 1. Concentrate storage; 2. Vibration control feeder; 3. Water inlet; 4. Water outlet; 5. Probe gas inlet; 6. Spray gun; 7. Oxygen inlet; 8. Flow meter; 9. Reaction zone; 10. Electric furnace; 11. Collector; 12. High-temperature probe; 13. Control thermocouple; 14. Spectrophotometer; 15. Data visualization and storage; 16. Concentrate inlet; 17. Observation hole; 18. Flash reaction furnace; 19. Air inlet; 20. Fiber optic probe; 21. Probe jacket. Detailed implementation manners

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] The present invention relates to a multi-flame monitoring system in the flash furnace and / or flash smelting process for treating sulfide concentrates and minerals, at least including the following parts:

[0058] a. An optoelectronic probe, which internally includes: (a.1) A spectral measurement sensor S1 of the optoelectronic detector type operating in the visible light range, preferably made of Si; (a.2) A spectral measurement sensor S2 of the optoelectronic detector type operating in the infrared range, preferably a spectral measurement sensor made of InGaAs alloy; and (a.3) An RGB image lens for capturing spectral measurements in the same area;

[0059] b. An S-type thermocouple for monitoring the furnace temperature;

[0060] c. A gas analyzer for measuring the O2(g) signal in the gas entering the gas purification stage from the gas delivery system of any type of flash or flash smelting furnace in a standard manner;

[0061] d. Cooling system, which is used to protect and cool the photoelectric probe. The cooling system includes a nitrogen injection jacket. There is a nitrogen injection jacket on each of the spectral measurement sensor S1, spectral measurement sensor S2, and the lens to remove dust on these detectors. Moreover, the spectral measurement sensor S1, spectral measurement sensor S2, and the lens are successively located in a cooling spray gun with a nitrogen injection jacket filled with a coolant (water or air). The nitrogen injection jacket contains a thermocouple for evaluating the temperature at the location of the photoelectric probe of the detector, thereby ensuring the normal operation of the cooling system;

[0062] e. A processing system and a control module consisting of two parts, which can generate on-line and real-time signals and incorporate them into the distributed control system of the existing mineral or concentrate burner in the furnace to establish control over the ratio of concentrate or mineral / oxygen in the process gas; the processing system and the control module include a data acquisition part and a processing software part;

[0063] The measuring devices used in the data acquisition part include a photoelectric probe (radiometer, RGB lens), a gas analyzer for measuring the O2(g) signal, a thermocouple, and an S-type thermocouple for monitoring the furnace temperature; the photoelectric probe, the S-type thermocouple for monitoring the furnace temperature, the gas analyzer for measuring the O2(g) signal, and the cooling system are all connected to the processing system and the control module, and the measuring devices communicate with the processing and softening part through a wired communication line;

[0064] The multi-flame monitoring system is applicable to Outokumpu flash smelting furnaces for copper, nickel, and lead;

[0065] The multi-flame monitoring system is applicable to Inco flash smelting furnaces for nickel;

[0066] The processing software part integrates statistical and metallurgical model algorithms specific to each component, provides indicators capable of diagnosing combustion quality, and modifies the equipment operation according to the reaction scheme according to the oxygen efficiency and performance, adjusts the solid / oxygen ratio of the burner and the oxygen percentage in the enriched air; the algorithm adopted by the processing software part determines the flame temperature through spectral thermal analysis based on the radiation curve characteristics of the combustion of sulfide minerals and concentrates. For copper concentrates, this relationship between intensity and wavelength reaches a peak at 588 nm and 766 nm.

[0067] In addition, the photoelectric probe can be placed anywhere with an observation angle. Relative to any direction of the flame, it can be observed from the projection of the burner, or observed at any angle towards the combustion flame or a partial view thereof. For reference, the photoelectric probe can be placed at the top of the reaction tower of the flash smelting furnace. Conversely, the thermocouple is located in the probe area. Figure 8 A schematic diagram showing the integration of system components is presented.

[0068] As can be seen from the above description, the monitoring system includes at least five measurement signals, three of which are obtained using optoelectronic devices that measure visible and near-infrared spectral radiation. The combustion flame temperature and the reactivity level of the oxidation reaction can be calculated. Based on the specific spectral information of the reaction chemical system related to the smelting and blowing processes in pyrometallurgy with colored flames, especially in the smelting process, the combustion flame temperature and the reactivity level of the oxidation reaction can be calculated. These two additional signals, one is for temperature monitoring through an S-type thermocouple in the optoelectronic probe area, and the other is the signal of the O2(g) component in the gas measured by a process gas analyzer after combustion.

[0069] The monitoring system utilizes RGB images and spectral analysis in the visible and near-infrared ranges. This is achieved using a spectrophotometer in the spectral range from visible light (365 nm) to near-infrared (1900 nm). In addition, the system determines the flame temperature through spectral pyrometry, with a wavelength range between 500 nm and 900 nm, preferably between 600 nm and 900 nm, where the emissivity of the molten phase is constant above its melting temperature and the temperature exceeds 1600 °C.

[0070] Furthermore, the measured intensity level can calculate the reactivity degree of the smelting reaction through an appropriate metallurgical model calibrated for a specific furnace. This is because the smelting reaction has specific peaks. For copper concentrate, they are found at approximately 588 nm and 766 nm, with the latter being a double peak. Combining this with the oxygen content in the gas at the exit of the reaction zone, the control criteria can be determined based on the Cu content target in matte or matte phase, and the combustion pursuit of concentrate and / or sulfide minerals, to maintain an appropriate oxygen distribution. In fact, the integrated signal from the integrated device, the O2(g) content, and the evaluation of the quality of the matte and slag phases produced by the furnace can quantitatively determine the effective conditions for appropriate combustion quality and generate operation monitoring indicators based on the mass balance and chemical properties of the molten phase. Therefore, by combining the device signals under appropriate smelting result conditions to generate reference parameters, it can be used for real-time comparison of the signals obtained from the system with the reference values, and define an online alarm when the obtained values deviate from the reference values. This can optimize the production process, minimize the dust generated by unburned particles, and control the chemical quality of the smelting products: the stability of the copper content in matte or matte phase, and minimize the excessive oxidation of slag.

[0071] The present invention combines control terms based on radiation variables (specific relationships of the measured radiation intensity as a function of wavelength in the visible and near-infrared ranges), optics, and chemistry, which can be proportionally optimized according to the requirements and particularities of the minerals or concentrates to be processed, and concretize the software parameters that interact with traditional device control terms, which at least include the solid feed rate, total O2(g) flow control, and the percentage of O2(g) in the process gas used as an oxidant.

[0072] In summary, the multi-flame monitoring system provided by the present invention facilitates the integration of a series of monitoring functions into the operation processes of flash smelting furnaces and flash smelting furnaces:

[0073] ● Online monitoring and control

[0074] ● Determination of combustion quality: The combustion quality is determined by using optoelectronic devices to quantify the evaluation parameters as radiation indicators, which are related to the process radiation intensity in the continuous wavelength range, where

[0075] Each chemical process related to the base metal being processed determines a specific value.

[0076] · Faster monitoring and control phase response speed: The system monitors the source of the combustion process, i.e., the flame reaction zone.

[0077] · The measurement of flame characteristics and combustion gases is non-invasive, so the measurement behavior does not change the operation of the furnace. As a non-invasive system, its maintenance cost is low, and the proposed sensor design is relatively simple. In fact, the diameter of the probe does not exceed 5 cm, demonstrating its non-invasiveness.

[0078] · In addition, the obtained signal can infer the flame temperature and incorporate the parameters into the operation control.

[0079] For base metal smelters, more stable operation can be translated into economic benefits, directly affecting:

[0080] · Equipment idle time (running time), because they are minimized and almost eliminated.

[0081] The chemical quality of the smelting process products: reducing the slag of excessive oxidation, increasing the recovery rate of the processed metal, continuously strengthening the stability of the processed metal content in the metal phase, and having a positive impact on the subsequent stages.

[0082] The furnaces adapted by the multi-flame monitoring system provided by the present invention include Outokumpu flash and / or flash smelting furnaces for copper, nickel, and lead smelting, inco-type flash and / or flash smelting furnaces for nickel smelting, and flash and / or flash smelting furnaces for processing sulfide minerals and / or concentrates in base metal production.

[0083] Examples

[0084] Example 1, laboratory flash smelting

[0085] An experimental study on the flash combustion of three copper concentrates was carried out using a laminar furnace (dropper). Table 1 shows the operating conditions of the furnace, and Table 2 shows the main components of the concentrate.

[0086] Table 1 Operating conditions of the laminar furnace:

[0087] Parameter Value Furnace temperature 411.7(℃) <![CDATA[Oxygen concentration in N2]]> 30％,45％,60％，80％

[0088] Table 2 Main components of the concentrate:

[0089] Concentrate type S (wt%) Cu (wt%) S / Cu ratio A 34.6 33.5 1.03 B 36.4 31.6 1.15 C 39.1 24.9 1.57

[0090] First, adjust the gas lance at the furnace top to allow the copper concentrate to enter. The copper concentrate is water-cooled to protect the optical measurement system and prevent the concentrate from burning in unwanted areas during the process, such as Figure 1 As shown, it is a schematic diagram of the furnace body. In addition, the lance in the central area ( Figure 2 , details of the furnace chamber and the monitoring system) can introduce an optical probe, providing a direct path for measuring the radiant energy in the form of light emitted by the concentrate during the reaction. Figure 1 And Figure 2 The detailed description corresponds to: 1 Concentrate storage; 2 Vibration-controlled feeder; 3 Water inlet; 4 Water outlet; 5 Probe gas inlet; 6 Lance mechanical inlet; 7 Oxygen inlet; 8 Flow meter; 9 Reaction zone; 10 Electric furnace; 11 Collector; 12 High-temperature probe; 13 Control thermocouple; 14 Spectrophotometer; 15 Data visualization and storage.

[0091] Use a vibrating mechanical feeder to introduce the concentrate particles into the reactor preheated to 500 °C at a feeding rate of 20 g / min for 2 minutes. The experiment is carried out with four different concentrations of O2(g) in N2(g). The calcined products obtained from this process are deposited in the collector for further analysis.

[0092] The results of Concentrate A, Concentrate B, and Concentrate C are shown in Figure 3 、 4 and 5 respectively, where a represents 30% oxygen, b represents 45% oxygen, c represents 60% oxygen, and d represents 80% oxygen.

[0093] According to Figure 3 and Figure 4 The results shown, the measurement results are sensitive to the reactivity of the process, where the higher the oxygen content in the combustion gas, the greater the measured signal intensity. Determine the flame temperature under different types of copper concentrates and O2(g) conditions, and the measured values provided are consistent with the results calculated from the appropriate reaction model. Table 3 shows the temperatures calculated using mass and heat balances and the measured temperatures.

[0094] Table 3 Temperatures calculated using mass and heat balances and the measured temperatures

[0095] Operation Temperature calculated from mass and energy balance, °C Measured temperature, °C A-30 1273 1277 A-45 1415 1419 A-60 1535 1536 A-80 1651 1655 B-30 1318 1317 B-45 1395 1394 B-60 1579 1579 B-80 1664 1662

[0096] Example 2. Flash smelting in Outokumpu reactor

[0097] Tests were carried out in an industrial furnace using the same probes as at the laboratory level. Figure 9 A schematic diagram of the sensor distribution in the probe to be introduced into the furnace is given. The operating conditions vary according to the feed rate and O2(g) in the combustion gas. The operating conditions are: S / Cu ratio in the concentrate is 0.88, and the feed rate is 75 tons per hour, as a reference.

[0098] Figure 6 A simple application scheme in industrial operation is given, where: 16 is the concentrate inlet, 17 is the observation hole, 18 is the flash reactor, 19 is the air inlet, 20 is the fiber optic probe, and 21 is the probe jacket. In Figure 7 , a is the radiation control corresponding to normal operation of the working condition, b corresponds to a 15% increase in both the O2(g) rate in the combustion gas and the reference feed rate, and c corresponds to a 15% increase in the O2(g) rate in the combustion gas while the reference feed rate increases by 5 - 10%.

[0099] The results show that a direct relationship can be established between the quantitative conditions for measuring the radiation intensity and the operating conditions.

[0100] What is not described in detail in this specification belongs to the prior art well-known to those skilled in the art. Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals, characterized in that: The system includes at least one set of optoelectronic probes, which include visible light and infrared light sensors and a lens for capturing RGB images; an S-type thermocouple for monitoring the furnace temperature; a gas analyzer for reading oxygen signals; a protection and cooling system for the probes; a processing system and a control module for distributed control. The optoelectronic probes, the S-type thermocouple for monitoring the furnace temperature, the gas analyzer for reading oxygen signals, and the protection and cooling system for the probes are all connected to the processing system and the control module; The optoelectronic probes can be placed at appropriate positions and at any angle to receive the nozzle flame signals to monitor all or part of the development process of the flame; The gas analyzer measures the oxygen signal in the gas entering the gas purification stage from the gas delivery system of the flash smelting furnace in a standard manner; The cooling system protects and cools the optoelectronic probes. The diameter of the optoelectronic probes is 75 mm - 1100 mm and they are installed in a set of cooling jackets. The coolant in the cooling jackets can be air or water; The protection system of the optoelectronic probes includes a set of nitrogen injection jackets for protecting the photodetectors and lenses of the optoelectronic probes; The optoelectronic probes are equipped with a thermocouple sleeve containing an S-type thermocouple for detecting the temperature at the location where the optoelectronic probes are located; The processing system and the control module generate on-line and real-time signals to adjust the oxygen-fuel ratio at the nozzle and the oxygen concentration in the enriched oxygen air. The processing system and the control module include a data acquisition part and a processing software part, and the measuring devices used in the data acquisition part communicate with the processing software part through wired communication lines; The data collected by the optoelectronic probes is combined with the measured oxygen data to generate the oxygen-fuel ratio in the nozzle area; The multi-flame monitoring system is applicable to the Outokumpu flash smelting furnaces for copper, nickel and lead; The multi-flame monitoring system is applicable to the Inco flash smelting furnace for nickel; The processing software part integrates statistical and metallurgical model algorithms specific to each component, provides indicators capable of diagnosing combustion quality, and modifies the operation of the equipment according to the oxygen efficiency and performance, adjusting the solid / oxygen ratio of the burner and the oxygen percentage in the oxygen-enriched air; the algorithm adopted by the processing software part determines the flame temperature by spectral thermal analysis according to the radiation curve characteristics of the combustion of sulfide minerals and concentrates. Modify the operation of the equipment according to the oxygen efficiency and performance, adjust the solid / oxygen ratio of the burner and the oxygen percentage in the oxygen-enriched air; the algorithm adopted by the processing software part determines the flame temperature by spectral thermal analysis according to the radiation curve characteristics of the combustion of sulfide minerals and concentrates.

2. The multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 1, characterized in that: The optoelectronic probes are located anywhere with an allowed viewing angle.

3. The multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 1, characterized in that: The signals measured by the optoelectronic probes are used to calculate the flame temperature and the reaction conversion rate of the oxidation reaction. The spectral information provided by the optoelectronic probes is combined with the oxygen analysis information to establish a control index for optimizing the solid / oxygen ratio entering the burner.

4. The multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 3, characterized in that: Both the spectral measurement sensor S1 and the spectral measurement sensor S2 are of the photodetector type.

5. The multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 1, characterized in that: The multi-flame monitoring system determines the combustion quality by using optoelectronic devices to quantify the evaluation parameters as radiation indexes. The parameters include at least the solid feed rate, the total oxygen flow control, and the percentage concentration of oxygen used as an oxidant in the process gas. The probe diameter in the multi-flame monitoring system does not exceed 5 cm, and the multi-flame monitoring system adopts a non-invasive measurement method to monitor the source of the reaction process.

6. The multi-flame monitoring system of a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 1, characterized in that: The multi-flame monitoring system uses RGB images and spectral analysis in the visible light and near-infrared ranges, which is realized by a spectrophotometer in the spectral range from visible light to near-infrared. The flame wavelength range determined by the multi-flame monitoring system is between 500 nm and 900 nm, where the emissivity of the molten phase is constant above its melting temperature and the temperature exceeds 1600 °C.

7. The multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 1, characterized in that: The intensity level measured by the multi-flame monitoring system calculates the reaction conversion rate of the smelting reaction through an appropriate metallurgical model calibrated for a specific furnace, quantitatively determines the effective conditions for the appropriate reaction, generates operation monitoring indicators based on the mass balance and chemical properties of the molten phase, combines the signals of the smelting results to generate reference parameters, and is used for the signals obtained by the system to be compared with the reference values in real time, and defines an online alarm when the obtained value deviates from the reference value.

8. The multi-flame monitoring system for a flash smelting furnace for processing metal sulfide concentrates and minerals according to claim 1, characterized in that: The smelting furnaces adapted by the multi-flame monitoring system include Outokumpu flash and / or flash smelting furnaces for copper, nickel, and lead smelting, inco-type flash and / or flash smelting furnaces for nickel smelting, and flash and / or flash smelting furnaces for processing sulfide minerals and / or other concentrates in base metal production.

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