Control system and control method for abatement equipment

Abstract

To provide a control system and method for reducing an amount of use to be used as possible at low cost, and maintaining a constant operation load.SOLUTION: There is provided a control system 100 of a detoxification facility 20 for washing acidic steam which is generated in a high pressure sulfuric acid leach process of nickel oxide ore using an autoclave 10, the detoxification facility 20 has a mechanism for, circulating water received from an external part in the detoxification facility 20, then bringing the circulated water with contact with acidic steam for washing, then delivering the circulated water to an external part. The control system 100 comprises: slurry flow rate measuring means 30 for measuring, a flow rate of slurry of nickel oxide ore and being provided on at least an upstream step of the autoclave 10; and control means 40 controlling, the mechanism of the detoxification facility 20. The control means 40 is configured to: acquire information of a flow rate of the slurry by the slurry flow rate measuring means 30, and adjust a flow rate of water to be delivered in the detoxification facility 20 according to the acquired flow rate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control system and a control method for abatement equipment in the hydrometallurgy of nickel oxide ore. [Background technology]

[0002] In recent years, high-pressure acid leaching (HPA) using sulfuric acid has attracted attention as a hydrometallurgical method for nickel oxide ore. This method does not include dry processing steps such as drying and roasting, and instead consists of a consistent hydrometallurgical process, which is advantageous in terms of energy and cost. It also has the advantage of being able to produce nickel-cobalt mixed sulfides with nickel content increased to approximately 50% by weight.

[0003] The hydrometallurgical process for nickel production using high-pressure acid leaching to obtain mixed nickel-cobalt sulfides involves two steps: a leaching process in which nickel oxide ore is subjected to high-temperature, high-pressure acid leaching to obtain a leach slurry; and a solid-liquid separation process in which the pH of the leach slurry obtained in the leaching process is adjusted in a preliminary neutralization process, followed by solid-liquid separation to obtain a crude nickel sulfate aqueous solution (leachate) that contains nickel, cobalt, and other impurities such as zinc.

[0004] In the leaching process of this hydrometallurgical method, a raw material slurry containing nickel oxide ore is heated and pressurized in a heater tank (heating and pressurizing equipment) in stages, and then supplied to an autoclave. In the autoclave, sulfuric acid, which has also been heated and pressurized, is added to the raw material slurry, and the mixture is stirred under high temperature and pressure to extract valuable metals through high-temperature, pressure acid leaching. The resulting leached slurry is then cooled and pressurized to room temperature and atmospheric pressure in a flash tank.

[0005] During this process, the autoclave and flash tank are adjusted to maintain an appropriate pressure by appropriately venting pressurized steam to the abatement equipment. Furthermore, because acidic vapors flow into the abatement equipment, the pH of the circulating water must be adjusted to neutral by discharging and receiving an appropriate amount of circulating water from the abatement equipment. If the amount of water discharged and received is small, the pH of the circulating water drops, increasing the environmental risk of acidic vapors being discharged from the abatement equipment, which can lead to reducing the operating load as a measure to adjust the pH. Conversely, if the amount of water discharged and received is large, there is the disadvantage that the amount of water used in the abatement equipment increases.

[0006] In response to such problems, for example, Patent Document 1 describes a wet-type detoxification device that includes an intake section to which harmful gases are supplied, a wet exhaust treatment section that is provided above the intake section and has a shower stall, an exhaust section that is continuous with the shower stall, a circulating water tank that is provided below the intake section, and circulating water supply means that supplies water from the circulating water tank to the shower stall, and that also includes water treatment means for purifying the water in the circulating water tank.

[0007] Furthermore, Patent Document 2 describes a detoxification device characterized by having a circulating water tank that circulates water to dissolve exhaust gas containing halogen in the water and then discharges the remaining exhaust gas, and a neutralization tank that treats the water, in which the exhaust gas has been dissolved and which has been discharged from the circulating water tank, with a neutralizing agent under pressure and returns the water to the circulating water tank.

[0008] However, in Patent Documents 1 and 2, it is necessary to add a water treatment means, a pressurization means, etc. to the detoxification equipment, which requires extensive improvements to the equipment. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-248018 [Patent Document 2] International Publication No. 2007 / 083426 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made to solve this situation, and aims to provide a control system and control method for abatement equipment that can maintain a constant operating load while minimizing water consumption at low cost. [Means for solving the problem]

[0011] The present inventors have found that the above problems can be solved by determining the flow rate of circulating water discharged from the detoxification equipment in accordance with the flow rate of the ore slurry supplied to the autoclave, and have completed the present invention.

[0012] That is, one aspect of the present invention is a control system for a detoxification equipment that cleans acidic vapor generated in a high-pressure sulfuric acid leaching process of nickel oxide ore using an autoclave, the detoxification equipment circulating water received from outside within the detoxification equipment and bringing the circulated water into contact with the acidic vapor to perform cleaning; After washing The control system includes at least a slurry flow rate measuring means that is provided on the upstream process side of the autoclave and measures the flow rate of the nickel oxide ore slurry, and a control means that controls the mechanism of the abatement equipment, and the control means acquires information on the slurry flow rate from the slurry flow rate measuring means and adjusts the discharge flow rate of water in the abatement equipment according to the flow rate.

[0013] According to one aspect of the present invention, the flow rate of the slurry leached with sulfuric acid is estimated by a slurry flow rate measuring means, and the flow rate of water discharged from the detoxification equipment is adjusted by a control means in accordance with the estimated slurry flow rate. This makes it possible to minimize water consumption while maintaining the pH of the circulating water at a neutral level, thereby maintaining a constant operational load.

[0014] In this case, in one aspect of the present invention, the control means may adjust the amount of liquid sent by the liquid sending pump.

[0015] In one aspect of the present invention, the control means may adjust the opening / closing degree of the adjustment valve.

[0016] Another aspect of the present invention is a method for controlling a decontamination equipment for cleaning acidic vapor generated in a high-pressure sulfuric acid leaching process of nickel oxide ore using an autoclave, the method comprising the steps of: circulating water received from outside within the decontamination equipment and bringing the circulated water into contact with the acidic vapor for cleaning; After washing The system has a mechanism for discharging the water to the outside, measures the flow rate of the nickel oxide ore slurry sent from the upstream process side of the autoclave, and adjusts the discharge flow rate of the water in the decontamination equipment according to the flow rate of the slurry.

[0017] According to another aspect of the present invention, the flow rate of the slurry leached with sulfuric acid is measured and estimated, and the water discharge flow rate in the detoxification equipment is adjusted according to the slurry flow rate, thereby minimizing water consumption while maintaining the pH of the circulating water at a neutral level, thereby maintaining a constant operating load. [Effects of the Invention]

[0018] According to the present invention, it is possible to minimize water consumption at low cost while maintaining a constant operating load. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a process diagram showing a hydrometallurgical method for producing nickel oxide ore. [Figure 2] 1 is a schematic diagram showing the configuration of each device in the leaching process and the configuration of a control system for a detoxification facility according to one embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing an example of abatement equipment to which the present invention is applied. DETAILED DESCRIPTION OF THE INVENTION

[0020] The control system and control method for abatement equipment according to the present invention will be described below with reference to the drawings in the following order. Note that the present invention is not limited to the following examples and can be modified as desired without departing from the gist of the present invention. 1. Hydrometallurgical refining method for nickel oxide ore 2. Control system and control method for abatement equipment 2-1. Overview of the leaching process 2-2. Control system and control method for abatement equipment

[0021] <1. Hydrometallurgical refining method for nickel oxide ore> First, prior to a more specific description of the control system and control method for abatement equipment, a brief description will be given of a hydrometallurgical method for nickel oxide ore to which the control system and control method for abatement equipment according to one embodiment of the present invention is applied. This hydrometallurgical method for nickel oxide ore is a hydrometallurgical method for recovering nickel and cobalt by leaching from nickel oxide ore using a high-pressure acid leaching process (HPAL process). Figure 1 shows an example of a process diagram of a hydrometallurgical method for nickel oxide ore using a high-pressure acid leaching process.

[0022] In the slurry preparation step S1, several types of nickel oxide ore are mixed to obtain a predetermined Ni content and impurity content, which are then mixed with water to form a slurry. The slurry is then sieved to a predetermined classification point to remove oversized ore particles, and only the undersized ore is used.

[0023] In the leaching step S2, the nickel oxide ore slurry obtained in the slurry preparation step S1 is subjected to a leaching treatment using, for example, high-pressure acid leaching. Specifically, sulfuric acid is added to an ore slurry obtained by mixing or otherwise processing the nickel oxide ore as raw material, and the ore is pressurized under high-temperature conditions of 220 to 280°C using, for example, a heat-resistant and pressure-resistant vessel (autoclave) to leach nickel, cobalt, and the like from the ore, thereby forming a leached slurry consisting of a leachate and a leach residue. A control system and a control method for abatement equipment according to one embodiment of the present invention are mainly applied to the leaching step S2. Details will be described later.

[0024] In the leaching step S2, excess sulfuric acid is added to improve the leaching rate, so the resulting leaching slurry contains excess sulfuric acid that was not involved in the leaching reaction, and its pH is very low.

[0025] For this reason, in the preliminary neutralization step S3, the pH of the leaching slurry obtained in the leaching step S2 is increased and adjusted to a predetermined range so that washing can be carried out efficiently during the multi-stage washing in the subsequent solid-liquid separation step S4. The pH can be adjusted to a predetermined range by adding a neutralizing agent such as limestone (calcium carbonate) slurry, for example.

[0026] In the solid-liquid separation step S4, the leaching slurry whose pH has been adjusted in the preliminary neutralization step S3 is washed in multiple stages to obtain a leachate containing nickel, cobalt, and zinc as an impurity element, and a leach residue.

[0027] In the neutralization step S5, the pH of the leachate separated in the solid-liquid separation step S4 is adjusted, and a neutralized precipitate containing impurity elements is separated to obtain a neutralized end solution containing zinc as well as nickel and cobalt. The pH of the leachate is adjusted by adding a neutralizing agent such as limestone (calcium carbonate) slurry.

[0028] In the dezincing step S6, a sulfiding agent such as hydrogen sulfide gas is added to the neutralization end solution obtained in the neutralization step S5 to perform a sulfiding treatment, thereby generating zinc sulfide, and the zinc sulfide is separated and removed to obtain a mother liquor for nickel recovery (dezincing end solution) containing nickel and cobalt. In the dezincing step S6, a sulfiding agent such as hydrogen sulfide gas is added to the crude nickel sulfate solution in a slightly pressurized reaction tank to sulfide the contained zinc, and the crude nickel sulfate solution containing the zinc sulfide is sent to a filter that performs solid-liquid separation using a pump and piping.

[0029] In the sulfurization step S7, the dezincification final liquor, which is the mother liquor for recovering nickel after the dezincification step S6, is used as the starting liquor for the sulfurization reaction, and hydrogen sulfide gas is blown into the starting liquor as a sulfurizing agent to cause a sulfurization reaction, thereby producing a mixed sulfide of nickel and cobalt with few impurity components and a barren liquor in which the concentrations of nickel and cobalt are stabilized at low levels.

[0030] The final neutralization step S8 neutralizes the leaching residue containing free sulfuric acid transferred from the solid-liquid separation step S4 and the filtrate (barren liquor) containing impurities such as magnesium, aluminum, and iron transferred from the sulfidation step S7. The leaching residue and filtrate are adjusted to a predetermined pH range using a neutralizing agent to produce a waste slurry (tailings). The tailings produced in this reaction tank are transferred to a tailings dam (waste storage facility).

[0031] <2. Control system and control method for abatement equipment> (2-1. Overview of the leaching process) So far, the flow of the hydrometallurgical method for producing nickel oxide ore has been explained in detail, but one embodiment of the present invention is applied to a detoxification facility that absorbs the acidic vapor generated in the leaching step S2 by bringing it into contact with water (circulating water) and preventing it from being released to the outside. Note that the detoxification facility can also be applied to other situations and processes as long as it recovers the generated gas by bringing it into contact with a liquid such as water in a similar manner, and one embodiment of the present invention is not necessarily limited to the leaching step in the hydrometallurgical method for producing nickel oxide ore.

[0032] FIG. 2 is a schematic diagram showing the configuration of each device in the leaching process and the configuration of a control system for abatement equipment according to one embodiment of the present invention. In the leaching process S2, the ore slurry prepared in the preceding slurry preparation process S1 is gradually heated and pressurized in a heater tank 50 (heating and pressurizing equipment) before being supplied to the autoclave 10. The heater tank 50 is not particularly limited, but a multi-stage countercurrent direct-heating heat exchanger is used as an example. Steam is used as the heating medium. For example, steam generated by a common method such as a boiler may be used. However, it is preferable to recover and circulate steam generated in a flash tank 60, which gradually lowers the temperature and pressure of the leached slurry discharged from the autoclave 10. Although FIG. 2 shows three heater tanks (first heater tank 50A, second heater tank 50B, and third heater tank 50C), the number of tanks is not limited to three.

[0033] The autoclave 10 is not particularly limited, and may be a vertical or horizontal pressurized vessel that is heated externally or by blowing in pressurized steam. In the autoclave, sulfuric acid leaches the nickel and cobalt contained in the ore, as well as some of the impurity elements such as iron, aluminum, and zinc, to obtain a leached slurry containing these elements.

[0034] The leached slurry is then fed from the autoclave 10 to a flash tank 60, which lowers the temperature and pressure of the leached slurry to room temperature and atmospheric pressure, and the temperature and pressure are lowered in stages. Although Fig. 2 shows three stages, namely, a first flash tank 60A, a second flash tank 60B, and a third flash tank 60C, the number of stages is not limited to three.

[0035] The flash tank 60 bridges the gap in operating conditions between the leaching step S2 and the next step. Specifically, a temperature of approximately 200 to 300°C is typically selected as the autoclave leaching condition to obtain a high leaching rate of nickel and cobalt. On the other hand, the subsequent preliminary neutralization step S3 or solid-liquid separation step S4 is typically operated under atmospheric pressure for safety and economic reasons. Therefore, in the flash tank 60, it is necessary to gradually lower the temperature and pressure while recovering pressurized steam from the high-temperature, high-pressure slurry after leaching.

[0036] Each flash tank 60 is provided with a steam discharge pipe 70 and the like, which gradually discharges pressurized steam from the high-temperature, high-pressure slurry after leaching to reduce the pressure. The steam discharge pipe 70 is made of a material and structure that can withstand high-temperature, high-pressure pressurized steam, and as shown in Figure 2 as an example, the steam is circulated from each flash tank 60 to a heater tank 50, which has similar temperatures and pressures. In the example shown in Figure 2, the first flash tank 60A is connected to the third heater tank 50C by a steam discharge pipe 70A, the second flash tank 60B is connected to the second heater tank 50B by a steam discharge pipe 70B, and the third flash tank 60C is connected to the first heater tank 50A by a steam discharge pipe 70C.

[0037] On the other hand, excess pressurized steam (acidic steam) that cannot be adjusted by the steam exhaust pipes 70 and the like is sent from the autoclave 10 and each flash tank 70 to the detoxification equipment 20. Figure 3 is a schematic diagram showing an example of a detoxification equipment to which the present invention is applied.

[0038] In the gas-liquid contact vessel 19 of the detoxification equipment 20, pressurized steam (acidic steam) is supplied from an autoclave or each flash tank to form a gas atmosphere, and water is supplied from above to bring the steam into gas-liquid contact, thereby absorbing the acidic components of the steam and cleaning (detoxifying) it. The pressurized steam (acidic steam) is supplied, for example, from the bottom of the gas-liquid contact vessel 19 and flows to the top of the gas-liquid contact vessel 19 by an ascending air current. A spraying means 22, for example, is provided above the gas-liquid contact vessel 19, and water (circulating water) is supplied (sprayed) thereto. Therefore, as the pressurized steam (acidic steam) ascends within the vessel as indicated by the dashed arrow in FIG. 3, it comes into gas-liquid contact with the water (circulating water) and is cleaned (detoxified). The detoxified steam, from which the acidic components have been cleaned, is discharged through a discharge pipe 23 provided at the top of the gas-liquid contact vessel 19 via a detoxification fan 21. At the time of discharge, it is preferable to confirm that the steam has been detoxified, for example, by a concentration measuring means or a pH measuring means.

[0039] Furthermore, the water supplied from the spraying means 22 comes into contact with the pressurized steam (acidic steam) and is then stored in the bottom 24 of the gas-liquid contact vessel 19. The water in the bottom 24 is sent again by the circulation pump 25 to the spraying means 22 above and circulated.

[0040] If water continues to circulate inside the gas-liquid contactor vessel 19, it will absorb acidic components from the pressurized steam and the pH of the circulating water will decrease, so new water is supplied (received) and discharged (discharged) to the gas-liquid contactor vessel 19 as appropriate. The intake and discharge of new water is carried out, for example, via liquid feed pumps 26 and 27 and adjustment valves 28 and 29. It is preferable that the pH of the water in the bottom 24 of the gas-liquid contactor vessel 19 is controlled using a pH measuring means or the like, and that after discharge, the water is neutralized and treated using an alkali or the like. Alternatively, an alkaline solution may be supplied to the gas-liquid contactor vessel 19 and an aqueous alkaline solution may be circulated.

[0041] (2-2. Control system and control method for abatement equipment) Next, a control system and a control method for a detoxification facility according to one embodiment of the present invention will be described. One aspect of the present invention is a control system 100 for a detoxification facility 20 that cleans acidic vapor generated in a high-pressure sulfuric acid leaching process of nickel oxide ore using an autoclave 10. The detoxification facility 20 circulates water received from the outside within the detoxification facility 20 and cleans the acidic vapor by bringing the circulated water into contact with the acidic vapor. After washing The control system 100 includes at least a slurry flow rate measuring means 30 that is provided on the upstream process side of the autoclave 10 and measures the flow rate of the nickel oxide ore slurry, and a control means 40 that controls the mechanism of the abatement equipment 20, and the control means 40 acquires information on the slurry flow rate from the slurry flow rate measuring means 30 and adjusts the discharge flow rate of water in the abatement equipment 20 according to the flow rate.

[0042] The slurry flow rate measuring means 30 measures the flow rate of the nickel oxide ore slurry, and may be, for example, an electromagnetic flow meter or an ultrasonic flow meter. The slurry flow rate measuring means 30 measures the state of the slurry after the above-mentioned slurry preparation step S1 until it is leached with sulfuric acid in the autoclave, i.e., the slurry flow rate on the upstream side of the autoclave 10. Therefore, as shown in FIG. 2 , the slurry flow rate measuring means 30 may be provided before the slurry is supplied to the heater tank 50, or may be provided between each of the heater tanks 50A, 50B, 50C or immediately before the slurry is supplied to the autoclave 10.

[0043] The control means 40 acquires information about the slurry flow rate from the slurry flow rate measuring means 30, and adjusts the water discharge flow rate in the abatement equipment 20 according to the flow rate. The control means 40 is implemented by a device having information processing and information communication functions, such as a personal computer (PC) or tablet terminal. As an example, information about the slurry flow rate measured by the slurry flow rate measuring means 30 is sent to the control means 40 by communication means (wired or wireless), and output processing information set in advance according to the slurry flow rate is sent to the equipment of the abatement equipment 20 to control the operation of the equipment.

[0044] As an example, the control means 40 can adjust the liquid feed rates of the liquid feed pumps 26 and 27. For example, the control means 40 may control the rotation speed of the liquid feed pumps 26 and 27 to control the liquid feed rates.

[0045] Alternatively, the control means 40 can adjust the opening and closing degrees of the regulating valves 28, 29. Depending on the opening and closing degrees of the regulating valves 28, 29, the amount of water on the receiving side or the dispensing side can also be adjusted.

[0046] The control means 40 adjusts the discharge flow rate of the circulating water. Therefore, it is preferable that the control means 40 controls at least the discharge-side liquid feed pump 27 or the regulating valve 29 (or both). In addition to these, the control means 40 may control the receiving-side liquid feed pump 26 or the regulating valve 28 (or both), but the amount of water on the receiving side may be adjusted so that the amount of water in the abatement equipment is constant.

[0047] The above is the configuration of a control system for a detoxification facility according to one embodiment of the present invention. Another aspect of the present invention is a control method for a detoxification facility that cleans acidic vapor generated in a high-pressure sulfuric acid leaching process of nickel oxide ore using an autoclave, the detoxification facility circulating water received from outside within the detoxification facility and bringing the circulated water into contact with the acidic vapor for cleaning, After washing The system has a mechanism for discharging the water to the outside, measures the flow rate of the nickel oxide ore slurry sent from the upstream process side of the autoclave, and adjusts the discharge flow rate of the water in the decontamination equipment according to the flow rate of the slurry.

[0048] As an example of adjustment, when the ore slurry flow rate is higher than the equipment design value, the discharge flow rate of circulating water is set to be higher, and when the ore slurry water volume is lower than the equipment design value, the discharge flow rate of circulating water is set to be lower. These set values ​​can be set, for example, based on empirical rules, so that the pH of the circulating water does not drop too much from the neutral range. As an example, the ore slurry flow rate and the discharge amount of circulating water can be set so that they are proportional to each other.

[0049] Although it is possible to adjust the amount of water in the decontamination equipment based on the pH of the circulating water, it is difficult to quickly adjust the amount of water delivered (discharge flow rate) in response to changes in pH because the pH of a neutral aqueous solution changes significantly and is not stable. Therefore, the method of adjusting the discharge flow rate of water in response to changes in the ore slurry flow rate according to the present invention is considered to be the most suitable.

[0050] As described above, according to the present invention, by measuring and estimating the flow rate of the slurry leached with sulfuric acid, the discharge flow rate of the water in the detoxification equipment can be adjusted according to the slurry flow rate, thereby minimizing the amount of water used and maintaining the pH of the circulating water at a neutral level, thereby maintaining a constant operational load. [Example]

[0051] EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples in any way.

[0052] The effect of applying the control method for abatement equipment according to one embodiment of the present invention (Example) was verified by using an operation in which the amount of circulating water discharged from a conventional abatement equipment was kept constant as a comparative example. Specifically, the equipment design value of the ore slurry flow rate and the amount of circulating water discharged from the conventional abatement equipment were set to 1 (100%), and in one embodiment of the present invention, the discharge flow rate of circulating water was changed according to changes in the flow rate of the ore slurry as shown in Table 1.

[0053] [Table 1]

[0054] (Effect 1) The pH of the circulating water in the abatement equipment was measured, and the average daily pH during annual operation was calculated. As a result, in an example in which one embodiment of the present invention was applied, the average daily pH was 7.4, which was higher than the average daily pH of 6.6 in the conventional comparative example. This made it possible to maintain the pH of the circulating water in the neutral range, and it was found that the environmental risk of discharging acidic vapor from the abatement equipment could be further reduced.

[0055] (Effect 2) The frequency with which the operational load was reduced due to a decrease in the pH of the circulating water was measured, and the average frequency per day was calculated. As a result, it was 0.2 times / day in the Example and 8.1 times / day in the Comparative Example. This shows that it is possible to significantly reduce the frequency with which the operational load is reduced due to a decrease in the pH of the circulating water in the decontamination equipment, and to maintain the operational load at a constant level.

[0056] (Effect 3) The amount of water used by the abatement equipment was measured, and the average daily flow rate for the year's operation was calculated. As a result, when the amount of water used in the comparative example was set to 100, the average daily flow rate in the example was 83, which means that water use could be reduced by 17%. This shows that water use can be saved.

[0057] Although one embodiment of the present invention and each example have been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and effects of the present invention. Therefore, all such modifications are intended to be included within the scope of the present invention.

[0058] For example, a term that is described at least once in the specification or drawings together with a different term having a broader or equivalent meaning can be replaced with that different term anywhere in the specification or drawings. Furthermore, the configurations of the control system and control method for the abatement equipment are not limited to those described in the embodiment and examples of the present invention, and various modifications are possible. [Explanation of symbols]

[0059] 10 autoclave, 19 gas-liquid contact vessel, 20 abatement equipment, 21 abatement fan, 22 spray means, 23 discharge pipe, 24 bottom (of gas-liquid contact vessel), 25 circulation pump, 26 liquid transfer pump (receiving side), 27 liquid transfer pump (discharging side), 28 regulating valve (receiving side), 29 regulating valve (discharging side), 30 slurry flow rate measuring means, 40 control means, 50 (50A, 50B, 50C) heater tank, 60 (60A, 60B, 60C) flash tank, 70 (70A, 70B, 70C) steam discharge piping, 100 control system

Claims

1. A control system for abatement equipment that cleans acid vapors generated in a high-pressure sulfuric acid leaching process of nickel oxide ore using an autoclave, comprising: the detoxification equipment has a mechanism for circulating water received from the outside within the detoxification equipment, cleaning the circulated water by bringing the acidic steam into contact with the water, and discharging the cleaned water to the outside; The control system includes at least a slurry flow rate measuring means provided on the upstream side of the autoclave for measuring the flow rate of the nickel oxide ore slurry; a control means for controlling the mechanism of the abatement equipment; Equipped with The control system for abatement equipment is characterized in that the control means acquires information on the flow rate of the slurry from the slurry flow rate measuring means, and adjusts the discharge flow rate of the water in the abatement equipment in accordance with the flow rate.

2. 2. The control system according to claim 1, wherein the control means adjusts the amount of liquid sent by the liquid sending pump.

3. 3. The control system according to claim 1, wherein the control means adjusts the opening / closing degree of a regulating valve.

4. A method for controlling a decontamination facility that cleans acid vapors generated in a high-pressure sulfuric acid leaching process of nickel oxide ore using an autoclave, comprising: the detoxification equipment has a mechanism for circulating water received from the outside within the detoxification equipment, cleaning the circulated water by bringing the acidic steam into contact with the water, and discharging the cleaned water to the outside; a method for controlling an abatement facility, comprising measuring a flow rate of the nickel oxide ore slurry sent from an upstream process side of the autoclave, and adjusting a discharge flow rate of the water in the abatement facility in accordance with the flow rate of the slurry.

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