JP2020147808A - Ore slurry transportation treatment plant and its operation method - Google Patents

Abstract

To make it possible to efficiently execute a hydrometallurgical process that can maintain utilization, even when trouble or the like occurs in a treatment of adjusting an ore slurry, in a high pressure acid leaching step thereafter.SOLUTION: The present invention relates to an ore slurry transportation treatment plant 1 that transfers an ore slurry of nickel oxide ore to a high pressure acid leaching apparatus 2. The plant 1 is provided with a storage tank 11 for storing the ore slurry, and a first isolation valve 61, a transportation pump 62, and a second isolation valve 63 in order from an upstream side to a downstream side, and two series of a transfer apparatus 10 having a transfer piping 12 for transferring the ore slurry from the storage tank 11 to the high pressure acid leaching equipment 2. A transfer piping 12 in the transportation equipment 10 of each series (A, B) is constituted of a main piping 21 and a preliminary piping 22, and between the two series of the transportation apparatuses 10A, 10B, the preliminary piping 22a, 22b are connected with each other with a series connection piping 30.SELECTED DRAWING: Figure 2

Description

The present invention relates to an ore slurry transfer processing plant used in a hydrometallurgical process of nickel oxide ore using a high-pressure acid leaching method and an operation method thereof, and in particular, a plant capable of maintaining a high operating rate and an operation method thereof. Regarding the driving method.

As one of the hydrometallurgical methods for nickel oxide ore, a high pressure acid leaching (HPAL) process using sulfuric acid is known. This process is different from the conventional dry smelting process, which is a general smelting method for nickel oxide ore, because there is no process of reducing or drying the oxide ore at high temperature, and the process is consistently performed in a wet process. It is advantageous in terms of target and cost. Further, a sulfide containing nickel and cobalt whose nickel grade is concentrated to about 50% by mass to 60% by mass (hereinafter, also referred to as "nickel-cobalt mixed sulfide") can be obtained, and nickel is purified to high purity. There is a feature that it can be done.

In the hydrometallurgical process of leaching nickel oxide ore as a raw material with high-pressure acid and recovering nickel as a product, the flow shown in FIG. 1 is generally executed (each step will be described later).

In the ore slurry preparation step in this hydrometallurgical process, nickel oxide ore is pulverized and sieved in a wet manner to obtain an ore slurry adjusted to a predetermined particle size, and the ore slurry is used as a next step, high-pressure acid. Supply to the leaching process.

Here, if any trouble occurs in the treatment of the ore slurry adjusting step, the supply of the ore slurry will be delayed, so that it is necessary to stop the addition of sulfuric acid in the treatment in the high-pressure acid leaching step.

For example, Patent Document 1 describes a method for preventing the process in the high-pressure acid leaching process from being forced to stop operation when a relatively small-scale trouble occurs in another process other than the high-pressure acid leaching process. Proposed. Specifically, the method described in Patent Document 1 lowers, lowers, and restarts the high-pressure acid leaching equipment when the trouble occurrence time in the equipment used in the process other than the high-pressure acid leaching process does not exceed a predetermined time. It is characterized in that the leaching slurry is self-circulated in the high-pressure acid leaching facility without performing the above.

Further, in Patent Document 2, in a plant having a plurality of sequences of the same process, troubles occur in the equipment in the predetermined process in a series of processes by connecting the processing equipments in the predetermined process with pipes. Even if this happens, the technology that minimizes the decrease in operating efficiency is disclosed, and it is a very effective technology in actual operation. Specifically, in Patent Document 2, for troubles in supply equipment such as utilities, hydrogen sulfide, coagulant, neutralizer, etc., the equipments are connected by piping and supplied to the troubled series. By doing so, a method for improving the utilization rate is disclosed.

However, these prior documents do not disclose or suggest a solution to the trouble in the ore slurry preparation step where serious trouble is likely to occur. In addition, it is difficult to secure an operating rate of 100% per series. In addition, a serious trouble in the ore slurry adjusting process includes, for example, a trouble that takes a long time to recover due to a failure of the agitator of the ore slurry storage tank or its electric motor.

JP-A-2010-31341 Japanese Unexamined Patent Publication No. 2011-225908

The present invention has been proposed in view of such circumstances, and even if a trouble occurs in the process of preparing the ore slurry in the hydrometallurgical process of nickel oxide ore, in the subsequent process. The purpose is to be able to maintain operation in a high-pressure acid leaching process and to efficiently execute hydrometallurgy processes.

(1) The first invention of the present invention is an ore slurry transfer processing plant that transfers an ore slurry obtained by slurrying nickel oxide ore to a high-pressure acid leaching facility, and is a storage tank for storing the ore slurry to be prepared. A first isolation valve, a transfer pump, and a second isolation valve are provided in this order from the upstream side to the downstream side through which the ore slurry flows, and the ore slurry supplied from the storage tank is provided. It is provided with two series of transfer pipes having a transfer pipe for transferring to the high-pressure acid leaching facility, and the transfer pipe in the transfer facility of each series is composed of a main pipe and a spare pipe, each of which is in the storage tank. It is an ore slurry transfer processing plant that is connected and the spare pipes are connected to each other by a series connection pipe at a position downstream of the transfer pump between the two series of transfer facilities.

(2) In the second invention of the present invention, in the first invention, the series connecting pipe is located downstream of the transfer pump in the spare pipe in the transfer facility of each series, and This is an ore slurry transfer processing plant connected at a position upstream of the second isolation valve.

(3) In the third invention of the present invention, in the first or second invention, the storage tank in the transfer facility of each series is connected to the adjustment tank for adjusting the ore slurry, respectively. The ore slurry prepared in the adjustment tank of the series is an ore slurry transfer processing plant that can be supplied to the storage tank in the transfer equipment of the mutual series.

(4) The fourth invention of the present invention is the operation method of the ore slurry transfer processing plant according to any one of the first to third inventions, and during normal operation, the storage in the transfer equipment of each series. The ore slurry supplied from the tank is transferred to the high-pressure acid leaching facility through the main pipe in the transfer pipe, and if an abnormality occurs in any one of the two series of transfer equipment, the other In the transfer facility of the series, the high-pressure acid is maintained from the spare pipe through the spare pipe of the series through the spare pipe of the series while maintaining the transfer of the ore slurry through the main pipe of the transfer pipe. This is an operation method of an ore slurry transfer processing plant that transfers the ore slurry to a leaching facility.

(5) In the fifth aspect of the present invention, in the fourth invention, when an abnormality occurs in the storage tank of any one series of the two series of transfer equipment, the transfer equipment of the one series can be used. The series with the first isolation valve and the second isolation valve provided in the main pipe closed and the second isolation valve provided in the spare pipe opened. This is an operation method of an ore slurry transfer processing plant in which the ore slurry supplied from the transfer facility of the other series is transferred to the high-pressure acid leaching facility through the spare pipe via a connecting pipe.

(6) In the sixth aspect of the present invention, in the fourth or fifth invention, the valve operation of the first isolation valve and the second isolation valve is performed after injecting water and washing with water. , It is an operation method of an ore slurry transfer processing plant.

According to the present invention, even if a trouble occurs in the process of adjusting the ore slurry, the operation of the process in the high-pressure acid leaching process which is the subsequent process can be maintained, and the wet product can be efficiently manufactured. Can carry out the smelting process.

It is a process diagram which shows an example of the flow of the wet smelting process of nickel oxide ore. It is a figure which shows an example of the structure of the ore slurry transfer processing plant. It is a block diagram of the ore slurry transfer processing plant, and is the figure for demonstrating the operation flow when the failure trouble occurs in the storage tank in one series of transfer facilities.

Hereinafter, specific embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention. In this specification, the notation "X to Y" (X and Y are arbitrary numerical values) means "X or more and Y or less".

≪1. Wet smelting process of nickel oxide ore ≫
In the ore slurry transfer processing plant according to the present invention, in the hydrometallurgical process of nickel oxide ore, the nickel oxide ore is pulverized and sieved in a wet manner to form a slurry to prepare the ore slurry. It is a plant used for.

Here, the hydrometallurgical process of nickel oxide ore will be outlined prior to the detailed description of the ore slurry transfer processing plant. FIG. 1 is a process diagram showing an example of the flow of a hydrometallurgical process for nickel oxide ore. As shown in the process chart, in the wet smelting process, the ore slurry adjusting step S1 for adjusting the ore slurry, the high-pressure acid leaching step S2 for leaching the ore slurry, and the obtained leaching slurry are leached with the leachate. A solid-liquid separation step S3 for separating into a residue, a neutralization step S4 for neutralizing the leachate to remove impurities, and a sulfurization step S5 for obtaining a nickel-cobalt mixed sulfide by subjecting the neutralizing final solution to sulfurization treatment. Has.

(1) Ore Slurry Adjustment Step The ore slurry adjustment step S1 is a step of obtaining an ore slurry adjusted to a predetermined particle size by pulverizing and sieving the raw material nickel oxide ore in a wet manner.

Here, as the nickel oxide ore, so-called laterite ore such as limonite ore and saprolite ore is mainly mentioned. The nickel content of laterite ore is usually 0.8-2.5% by weight and is contained as a hydroxide or magnesium silicate mineral.

The adjustment of the ore slurry in the ore slurry adjusting step S1 is performed, for example, in the slurry adjusting tank. The ore slurry prepared in the adjustment tank is temporarily stored in the storage tank, and then is processed in the next step, the high-pressure acid leaching step S2, through a predetermined transfer pipe (high-pressure acid leaching facility). Will be transferred to. The control of the transfer of the ore slurry will be described in detail later.

(2) High-pressure acid leaching step In the high-pressure acid leaching step S2, sulfuric acid is added to the ore slurry and stirred while pressurizing at a temperature of 220 ° C. to 280 ° C. This is a step of producing a leaching slurry composed of. The treatment in the high-pressure acid leaching step S2 is performed in a high-pressure acid leaching facility equipped with, for example, a high-temperature pressure vessel (autoclave).

More specifically, in the high-pressure acid leaching step S2, the raw material slurry is heated by mixing it with steam in a pressure-resistant container for heating (heater tank), and then the heated raw material slurry is leached in the pressure-resistant container for leaching (heater tank). It is leached by mixing it with an acid under high temperature and high pressure by steam or the like in an autoclave), and after leaching, it is cooled by separating and recovering water as steam from the slurry after leaching in a pressure reducing container (flash vessel).

(3) Solid-liquid separation step The solid-liquid separation step S3 performs a solid-liquid separation treatment on the leaching slurry generated by the treatment in the high-pressure acid leaching step S2, and contains a leachate containing nickel, cobalt, etc., and mainly hematite. This is a step of separating the leaching residue. The solid-liquid separation treatment is performed, for example, by mixing the leaching slurry with the cleaning liquid and then using a solid-liquid separation facility such as a thickener using a coagulant. The separated leachate is transferred to the neutralization step S4 of the next step, while the leachate residue is recovered from the bottom of the thickener.

(4) Neutralization Step The neutralization step S4 is a step of adding a neutralizing agent to the obtained leachate to adjust the pH to obtain a neutralized starch containing an impurity element and a neutralized liquid. By this neutralization treatment, valuable metals such as nickel and cobalt are contained in the liquid after neutralization, and most of the impurities such as iron and aluminum become neutralized starch. As the neutralizing agent, for example, calcium carbonate, slaked lime, sodium hydroxide and the like can be used, and it is preferable to adjust the pH to the range of 1 to 4 while suppressing the oxidation of the leachate.

(5) Sulfide Step The sulfurization step S5 is a step of adding a sulfurizing agent to the neutralized liquid to obtain nickel and cobalt sulfide (nickel-cobalt mixed sulfide) and a post-sulfide liquid. Specifically, sulfides such as hydrogen sulfide gas, sodium sulfide, and sodium sulfide sulfide are added to the neutralized liquid to sulfide nickel and cobalt contained in the neutralized liquid in the form of sulfides. Cause a reaction. As a result, nickel and cobalt sulfides having a small amount of impurity components and a post-sulfurization liquid (poor liquid) in which the nickel concentration is stabilized at a low level are produced. The nickel-cobalt mixed sulfide slurry produced by the sulfurization treatment is subjected to sedimentation separation treatment to separate and recover the nickel-cobalt mixed sulfide from the bottom of the thickener, while the post-sulfurization liquid overflows and recovers.

≪2. Ore slurry transfer processing plant ≫
FIG. 2 is a diagram showing an example of the configuration of an ore slurry transfer processing plant. The ore slurry transfer processing plant (hereinafter, also simply referred to as “plant”) 1 has a storage tank 11 for storing the ore slurry to be adjusted, and a transfer pipe 12 for transferring the ore slurry to the high-pressure acid leaching facility 2. It is equipped with two lines of transfer equipment 10. In the present specification, regarding the two series, the first series is A series, the second series is B series, the transfer equipment 10 of the first series is designated by the symbol "10A", and the transfer equipment of the second series is used. Each 10 is distinguished by the reference numeral "10B". Further, the storage tanks 11 provided in the transfer facilities 10A and 10B of each series are the storage tanks 11a and 11b, and the transfer pipe 12 is the transfer pipes 12a and 12b.

Further, the transfer pipe 12 in the transfer facility 10 is composed of two main pipes 21 (21a, 21b) and spare pipes 22 (22a, 22b). Each of the main pipe 21 and the spare pipe 22 is connected to the storage tank 11.

Then, between the two series of transfer facilities 10A and 10B, the spare pipes 22a and 22b are connected to each other by the series connecting pipe 30 at a predetermined position.

[Transfer equipment]
As described above, the transfer facility 10 is composed of two series (10A, 10B) of A series and B series. The transfer facility 10 has a storage tank 11 and a transfer pipe 12, and high-pressure acid leaching of the ore slurry prepared by the adjustment tanks 40 (40a, 40b) which are facilities on the upstream side of the storage tank 11. Transfer to equipment 2 (2A, 2B).

The high-pressure acid leaching facility 2 is a facility (leaching reaction tank) used for the leaching process in the high-pressure acid leaching step S2, which is the next step of the ore slurry adjusting step S1 in the hydrometallurgical process, and can be used for ore slurry. Nickel and cobalt contained in the ore are acid-leached by accommodating and adding sulfuric acid under high temperature and high pressure.

(Storage tank)
The storage tank 11 is a tank that temporarily stores the ore slurry supplied from the adjustment tank 40 that prepares the raw material nickel oxide ore into the ore slurry.

The storage tank 11 is provided with, for example, a stirring device including a stirring shaft and stirring blades, and stores the stored ore slurry while stirring. By storing the ore slurry while stirring in this way, it is possible to suppress the sedimentation of the ore in the slurry.

Here, in the storage tank 11, troubles such as a failure of the stirring device may occur. When such a trouble occurs, the supply of the ore slurry stored in the storage tank to the treatment (high pressure acid leaching facility 2) in the next step, the high pressure acid leaching step S2, is stopped. This prevents a decrease in the leaching rate in the high-pressure acid leaching step S2. On the other hand, the suspension of the supply of the ore slurry significantly reduces the leaching efficiency and the operating efficiency of the entire wet smelting process of nickel oxide ore.

(Transfer piping)
The transfer pipe 12 is a flow path for supplying the ore slurry stored in the storage tank 11 to the high-pressure acid leaching facility 2 that performs the high-pressure acid leaching process. In the transfer pipe 12, the ore slurry flows and is supplied from the end (upstream side) connected to the storage tank 11 to the end (downstream side) connected to the high-pressure acid leaching facility 2.

The transfer pipe 12 is provided with a first isolation valve 61, a transfer pump 62, and a second isolation valve 63 in this order from the upstream side to the downstream side. As long as these devices (valves and pumps) are installed side by side in order from the upstream side to the downstream side of the transfer pipe 12, the distance and size between the devices are not particularly limited.

A first isolation valve 61, a transfer pump 62, and a second isolation valve 63 are provided in each of the transfer pipes 12a and 12b of the transfer facilities 10A and 10B, and similarly, the first isolation valve 61 is provided. The reference numerals are distinguished as the isolation valves 61a and 61b, the transfer pumps 62a and 62b, and the second isolation valves 63a and 63b.

-Isolation valve The isolation valves 61 and 63 control the flow of the ore slurry in the transfer pipe 12, and can be configured by an ON / OFF valve that controls whether or not the ore slurry can be distributed. Isolation valves 61 and 63 take the form of "open (ON) state" and "closed (OFF) state" by valve operation, enable the flow of ore slurry by "open state", and ore by "closed state". Negative distribution of slurry.

The first isolation valve 61 is provided on the upstream side of the transfer pipe 12, and acts to control the flow of the ore slurry in the transfer pipe 12. Further, the second isolation valve 63 is provided on the downstream side of the transfer pipe 12 so as to control the subsequent distribution of the ore slurry that has flowed through the transfer pipe 12, that is, the transfer to the high-pressure acid leaching facility 2. Acts on.

-Transfer pump The transfer pump 62 is composed of, for example, a metering pump or the like. The transfer pump 62 draws the ore slurry into the transfer pipe 12 and causes it to flow in, and transfers the ore slurry that has flowed in to the downstream side through the transfer pipe 12.

The transfer pump 62 is provided so as to be located between the first isolation valve 61 and the second isolation valve 63.

Here, the transfer pipe 12 is composed of a main pipe 21 which is a main distribution line and a spare pipe 22 which is a backup distribution line. The main pipe 21 is a main line used during normal operation. The spare pipe 22 is a backup line used when the main pipe 21 is in an unusable state due to periodic inspection or replacement. By providing the main pipe 21 and the spare pipe 22 in this way, it is possible to prevent the transfer of the ore slurry from the transfer facility 10 from being stopped and to suppress a decrease in operation efficiency.

In both the transfer equipment 10A of the A series and the transfer equipment 10B of the B series, the main pipes 21a and 21b and the spare pipes 22a and 22b are provided in the respective transfer pipes 12a and 12b.

[Series connection piping]
The series connecting pipe 30 is a pipe that connects two series of transfer equipment 10A and transfer equipment 10B. Series connection pipe 30 has one end portion _{30 e1} to the preliminary pipe 22a which constitutes a transfer pipe 12a, thereby connecting the other end portion _{30 e2} to the preliminary pipe 22b constituting the transfer pipe 12b, the transport and the transport facilities 10A It is connected to the equipment 10B.

As will be described in detail later, the series connecting pipe 30 connects two series of transfer equipments 10A and 10B, and one series of transfer equipment 10 (for example, 10A) to the other series via the series connecting pipe 30. Allows the supply of ore slurry to the transfer facility 10 (eg 10B). Further, the supply of the ore slurry between the two series of transfer facilities 10A and 10B via the series connection pipe 30 utilizes the spare pipes 22a and 22b of the respective transfer facilities 10A and 10B, and therefore, each of them. This is an action that is achieved by providing spare pipes 22a and 22b, which are backup lines, in the transfer facilities 10A and 10B.

The series connecting pipe 30 is connected to the spare pipes 22a and 22b of the transfer equipments 10A and 10B of each series at a position downstream from the position where the transfer pumps 62a and 62b are provided. As a result, when the ore slurry is supplied from the transfer facility 10 (for example, 10A) of one series to the transfer facility 10 (for example, 10B) of the other series via the series connection pipe 30, the transfer pipe 12 of the supply source By the action of the transfer pump 62 (62a) in (12a), it can be effectively supplied to the transfer facility 10 (10B) at the supply destination.

Further, the series connecting pipe 30 is located on the downstream side of the position where the transfer pumps 62a and 62b are provided as described above, and is on the upstream side of the position where the second isolation valves 63a and 63b are provided. It is preferable that they are connected at the position of. As a result, the ore slurry is supplied to each other of the transfer facilities 10A and 10B via the series connecting pipe 30, and then high-pressure acid leaching is performed through the spare pipe 22 (22b) of the transfer facility 10 (for example, 10B) of the supply destination. When the ore slurry is transferred to the equipment 2 (2b), the final control (ON / OFF) of the transfer can be performed by the second isolation valve 63 (63b).

[Adjustment tank]
The adjustment tank 40 is a tank for adjusting an ore slurry, and adjusts the raw material nickel oxide ore into an ore slurry (ore slurry) having a predetermined particle size by pulverizing and sieving in a wet manner. The ore slurry prepared in the adjusting tank 40 is supplied to the above-mentioned transfer facility 10 and transferred to the high-pressure acid leaching facility 2 through the transfer facility 10.

The adjustment tank 40 is provided for each series so as to correspond to the two series of transfer facilities 10A and 10B. Regarding the adjustment tank 40, the one corresponding to the transfer equipment 10A of the A series is referred to as the adjustment tank 40A, and the one corresponding to the transfer equipment 10B of the B series is referred to as the adjustment tank 40B. For example, in the adjusting tank 40A, the ore slurry prepared in the tank is supplied to the storage tank 11a in the transfer facility 10A through the supply pipe 41a. Similarly, in the adjusting tank 40B, the ore slurry prepared in the tank is supplied to the storage tank 11b in the transfer facility 10B through the supply pipe 41b.

Here, in the adjusting tanks 40 (40A, 40B) having two series, the supply pipes 41a and 41b are connected to each other by the connecting pipe 42. Thereby, for example, the ore slurry prepared in the adjusting tank 40A can be supplied to the B-series transfer facility 10B via the connecting pipe 42. Further, the ore slurry prepared in the adjusting tank 40B can be supplied to the A-series transfer facility 10A via the connecting pipe 42. Although not shown, the supply of ore slurry from the adjustment tank 40 (40A, 40B) is provided by providing a valve at the connection point between the supply pipes 41a and 41b connected to the adjustment tanks 40A and 40B and the connection pipe 42. You can control the destination.

≪3. Operation method of ore slurry transfer processing plant (transfer method of ore slurry) ≫
Next, an operation method of the ore slurry transfer processing plant 1 having the above-described configuration will be described. As shown in the process diagram of FIG. 1, the ore slurry prepared in the ore slurry adjusting step S1 is transferred to the high-pressure acid leaching facility 2 and subjected to the treatment in the high-pressure acid leaching step S2. As described above, the ore slurry prepared in the ore slurry adjusting step S1 is charged into the high-pressure acid leaching facility 2 (including, for example, a heater tank made of a pressure-resistant container) via a pump.

[Operation during normal (normal) operation]
The plant 1 is provided with two series (10A, 10B) of transfer equipment 10 having a storage tank 11 for storing the ore slurry to be adjusted and a transfer pipe 12 for transferring the ore slurry to the high-pressure acid leaching facility 2. Further, the transfer pipe 12 in the transfer facility 10 is composed of two main pipes 21 (21a, 21b) and spare pipes 22 (22a, 22b).

The flow of operation during normal operation will be described with reference to FIG. During normal operation, the ore slurry is stored in the storage tanks 11a and 11b in the transfer facilities 10A and 10B provided in the plant 1, respectively. The storage tanks 11a and 11b are supplied with the adjusted ore slurry from the adjustment tanks 40A and 40B provided corresponding to the transfer facilities 10A and 10B of each series, respectively.

Then, the ore slurry stored in the storage tanks 11a and 11b for a certain period of time is transferred to the high-pressure acid leaching facilities 2A and 2B through the transfer pipes 12a and 12b in each series.

Specifically, in the transfer facility 10A, when the ore slurry is transferred from the storage tank 11a, the valve of the main pipe 21a in the transfer pipe 12a is set to the "open" state, and the valve of the spare pipe 22a is set to the "closed" state. In addition. The black paint in FIG. 2 indicates the "open" state (ON state), and the white paint indicates the "closed" state (OFF state).

That is, the ore slurry can be circulated with the first isolation valve 61a provided in the main pipe 21a in the "open" state. Further, the operation of the transfer pump 62a of the main pipe 21a is turned on so that the ore slurry can be transferred to the downstream side. Further, the second isolation valve 63a of the main pipe 21a is set to the "open" state so that the ore slurry can be circulated. As a result, the ore slurry can be transferred from the storage tank 11a through the main pipe 21a.

On the other hand, the first isolation valve 61a provided in the spare pipe 22a is in a "closed" state to prevent the flow of the ore slurry. Further, the operation of the transfer pump 62a of the spare pipe 22a is turned off so that the ore slurry cannot be transferred to the downstream side. Further, the second isolation valve 63a of the spare pipe 22a is set to the "closed" state to disable the flow of the ore slurry. This makes it impossible to transfer the ore slurry from the storage tank 11a through the spare pipe 22a. As described above, the spare pipe 22 is a backup line used when the main pipe 21 is in an unusable state due to periodic inspection or replacement. By providing the main pipe 21 and the spare pipe 22 in this way, it is possible to prevent the transfer of the ore slurry from the transfer facility 10 from being stopped and to suppress a decrease in operation efficiency.

Similarly, in the transfer facility 10B, when the ore slurry is transferred from the storage tank 11b, the valve of the main pipe 21b in the transfer pipe 12b is set to the "open" state, and the valve of the spare pipe 22b is set to the "closed" state. That is, the first isolation valve 61b of the main pipe 21b is set to the "open" state, the operation of the transfer pump 62b is set to the ON state, the second isolation valve 63b is set to the "open" state, and the main pipe is started from the storage tank 11b. Allows the transfer of ore slurry through 21b. On the other hand, the first isolation valve 61b of the spare pipe 22b is in the "closed" state, the operation of the transfer pump 62b is turned off, the second isolation valve 63b is in the "closed" state, and the storage tank 11b is reserved. The transfer of the ore slurry through the pipe 22b is disabled.

In this way, during normal operation, the ore slurry can be transferred from the storage tanks 11a and 11b to the high-pressure acid leaching facility 2 through the main pipes 21a and 21b in the transfer facilities 10A and 10B. ..

[Driving when trouble occurs]
By the way, in such a transfer facility 10, troubles such as a failure of the stirring device may occur in the storage tank 11. Conventionally, when such a trouble occurs, the transfer of the ore slurry stored in the failed storage tank to the high-pressure acid leaching facility has been stopped. However, stopping the transfer of the ore slurry reduces the total amount of the ore slurry processed in the subsequent step, that is, the high-pressure acid leaching step S2 (the amount of processing in the entire operating plant), and lowers the operating efficiency.

Therefore, in the operation method of the plant 1 according to the present invention, when an abnormality (for example, a failure of the storage tank 11b) occurs in any one of the two series of transfer facilities 10A and 10B (for example, 10B), the series connecting pipe Through 30, it is possible to transfer the ore slurry through another series (series without failure (10A)).

More specifically, the flow of operation when a trouble occurs will be described with reference to FIG. FIG. 3 is a configuration diagram of an ore slurry transfer processing plant similar to that of FIG. 2, and is a diagram for explaining an operation flow when a failure trouble occurs in the storage tank 11b in the transfer facility 10B, which is one series. is there. In FIG. 3, a failure trouble of the storage tank 11b is indicated by an “x” mark.

When a trouble occurs, first, in the transfer equipment 10B provided with the storage tank 11b in which the trouble has occurred, the valve of the main pipe 21b, which was in the “open” state during normal operation, is put into the “closed” state. That is, the first isolation valve 61b provided in the main pipe 21b is set to the "closed" state, the operation of the transfer pump 62b is set to the OFF state, and the second isolation valve 63b is set to the "closed" state. This prevents the ore slurry, which has not been in a good storage state due to a failure problem, from being transferred to the high-pressure acid leaching facility 2B through the transfer pipe 12b.

Next, in the transfer facility 10B provided with the storage tank 11b in which the trouble has occurred, the second valve installed in the spare pipe 22b, which was in the “closed” state during normal operation, is on the most downstream side through which the ore slurry flows. Only the isolation valve 63b of the above is set to the "open" state. As a result, as will be described in detail later, the ore slurry can be transferred from the trouble-free transfer facility 10A to the middle of the spare pipe 22b of the transfer facility 10B via the series connecting pipe 30, and the spare pipe thereof. The ore slurry can be transferred to the high-pressure acid leaching facility 2B through 22b.

Next, in the transfer facility 10A in which no failure trouble has occurred, the operation during normal operation, that is, the transfer of the ore slurry through the main pipe 21a of the transfer pipe 12a is maintained. That is, the first isolation valve 61a in the main pipe 21a is maintained in the "open" state, the operation of the transfer pump 62a is maintained in the ON state, and the second isolation valve 63a is maintained in the "open" state. The transfer of the ore slurry through the main pipe 21a is maintained.

Then, while maintaining the transfer of the ore slurry through the main pipe 21a, a part of the valves provided in the spare pipe 22a constituting the transfer pipe 12a is put into the "open" state. Specifically, among the valves provided in the spare pipe 22a in the transfer pipe 12a, the first isolation valve 61a located on the upstream side is set to the "open" state, and the operation of the transfer pump 62a is turned on. To. The first isolation valve 61a and the transfer pump 62a for switching to the "open" state are valves provided in the spare pipe 22a, which is a backup line, and are in the "closed" state during normal operation. As a result, in the transfer facility 10A, a part of the ore slurry stored in the storage tank 11a is distributed not only in the main pipe 21a but also in the spare pipe 22a.

On the other hand, among the valves provided in the spare pipe 22a in the transfer facility 10A, the second isolation valve 63a existing at the most downstream is maintained in the "closed" state. As a result, the ore slurry that has been circulated to the spare pipe 22a is limited to the circulation to the second isolation valve 63 even in the spare pipe 22a.

Here, the plant 1 is a pipe connecting the two series of transfer equipment 10A and the transfer equipment 10B, and the end portions 30 _e1 and 30 _e2 are connected to the spare pipes 22a and 22b of the respective series. A series connecting pipe 30 for connecting the transfer pipe 12a of the transfer equipment 10A and the transfer pipe 12b of the transfer equipment 10B is provided. Further, the series connecting pipe 30 has a connection point with the spare pipes 22a and 22b at a position downstream of the transfer pumps 62a and 62b and at a position upstream of the second isolation valves 63a and 63b. It is said.

Therefore, in the transfer facility 10A, when the first isolation valve 61a in the backup line 22a is set to the "open" state and the transfer pump 62a is turned on, one of the ore slurries stored in the storage tank 11a. After the portion is distributed to the spare pipe 22a, it is supplied into the transfer facility 10B via the series connecting pipe 30.

As described above, in the transfer facility 10B, all the valves provided in the main pipe 21b are in the "closed" state, but among the valves provided in the spare pipe 22b to which the series connecting pipe 30 is connected, the most. Only the second isolation valve 63b on the downstream side is in the "open" state. From this, the ore slurry supplied from the transfer facility 10A via the series connecting pipe 30 enters the transfer facility 10B (spare pipe 22b in the transfer facility 10B) and then is in the “open” state. It will be transferred to the high-pressure acid leaching facility 2B through the isolation valve 63b.

Since the first isolation valve 61a provided in the spare pipe 22b of the transfer equipment 10B is in the "closed" state, it is upstream of the ore slurry supplied to the transfer equipment 10B via the series connecting pipe 30. Backflow to the side (direction of the storage tank 11b) can be prevented.

In this way, when the storage tank 11 (11b) in the transfer facility 10 (10B) of one of the two series fails, the transfer facility 10 (10A) of the series in which the failure does not occur occurs. ), The spare pipe 22 (22a) is used in parallel (used in parallel with the main pipe 21 (21a)), and then the transfer facility 10 (10B) in which the storage tank has a failure via the series connecting pipe 30 is started. The ore slurry is supplied inside.

As a result, it is possible to prevent a situation in which the ore slurry is not supplied to the high-pressure acid leaching facility 2 (2B) corresponding to the series in which the failure has occurred, and the operating rate of the treatment in the high-pressure acid leaching step S2 is lowered. This can be effectively prevented. As a result, it is possible to prevent a decrease in the operational efficiency of the wet smelting process of nickel oxide ore.

By the way, the ore slurry prepared in the adjusting tanks 40A and 40B of each series can be supplied to the storage tanks 11a and 11b of the transfer facilities 10A and 10B of each series. That is, for example, the ore slurry adjusted in the adjustment tank 40A in the A series is supplied in the B series via the connecting pipe 42 connected to the supply pipe 41a for supplying the ore slurry from the adjustment tank 40A to the storage tank 11a. The pipe 41b can be circulated and supplied to the storage tank 11b of the transfer facility 10B.

Therefore, as in the above-mentioned example, when a trouble occurs in the storage tank 11b in the transfer facility 10B, the supply of the ore slurry from the adjustment tank 40 may also be controlled. Specifically, when a trouble occurs in the storage tank 11b, the adjustment tank 40B of the B series, which is the same series, is operating normally. Therefore, the ore slurry adjusted in the adjustment tank 40B is used. It is supplied to the storage tank 11a in the transfer facility 10A of the A series via the connecting pipe 42. Then, the ore slurry adjusted by the adjusting tank 40A and the ore slurry adjusted by the adjusting tank 40B are stored in the storage tank 11a.

As described above, in the transfer facility 10A, the transfer of the ore slurry through the spare pipe 22a is operating in parallel, that is, the transfer facility 10B passes through the spare pipe 22a of the transfer facility 10A and then through the series connecting pipe 30. A part of the ore slurry is transferred to the high-pressure acid leaching facility 2B corresponding to the above. At this time, the ore slurry adjusted by the adjusting tank 40A and the ore slurry adjusted by the adjusting tank 40B are stored in the storage tank 11a of the transfer facility 10A, which causes a trouble in the transfer facility 10B. Even if this is the case, both the transfer amount of the ore slurry transferred to the high-pressure acid leaching facility 2A and the transfer amount of the ore slurry transferred to the high-pressure acid leaching facility 2B should be substantially the same as the transfer amount during normal operation. Can be done.

That is, in a state where the ore slurry adjusted by the adjusting tank 40A and the ore slurry adjusted by the adjusting tank 40B are stored in the storage tank 11a of the transfer facility 10A, the storage tank 11a usually stores the ore slurry. It means that twice the amount of ore slurry stored at the time of operation is stored. In the transfer facility 10A, the transfer of the ore slurry to the high-pressure acid leaching facility 2A through the main pipe 21a is continued as in the normal operation. On the other hand, the spare pipe 22a is also in a state where the ore slurry can be distributed in parallel, and is transferred to the high-pressure acid leaching facility 2B of the B series via the series connecting pipe 30. Therefore, if twice the amount of ore slurry as usual is stored in the storage tank 11a, the amount of ore slurry transferred to the high-pressure acid leaching facility 2A by the normal operation of the transfer facility 10A is halved, that is, the normal operation. The amount can be the same as during operation, while the amount of ore slurry transferred from the transfer facility 10A to the high-pressure acid leaching facility 2B corresponding to the transfer facility 10B via the series connecting pipe 30 is also half that amount, that is, The amount can be the same as during normal operation.

By operating in this way, it is possible to transfer the ore slurry to the high-pressure acid leaching facility 2B corresponding to the series in which the failure has occurred, and it is possible to prevent the situation where the high-pressure acid leaching facility 2B is stopped. In addition, the amount of ore slurry that can be supplied to the high-pressure acid leaching facility 2B can be set to the same level as during normal operation. As a result, it is possible to more effectively prevent a decrease in the operating rate of the treatment in the high-pressure acid leaching step S2.

The order of control of the open state and the closed state is not limited to the order described above. While performing the operation, while preventing the ore slurry from being transferred to an unintended location, the ore slurry is finally controlled to the open / closed state of the valve as shown in FIG. 3, for example, through the series connecting pipe 30. It is only necessary to be able to transfer.

Further, when operating the valves of the first isolation valve 61 and the second isolation valve 63 provided in the transfer pipe 12 of the transfer facility 10, it is preferable to perform the operation after injecting water and washing with water. In the valve provided in the transfer pipe 12 for circulating the ore slurry, the ore slurry may be bitten, and if the bite occurs, the valve may malfunction and proper valve control cannot be performed.

In particular, when a failure problem occurs in the transfer facility 10 as described above, appropriate valve operation is required in order to minimize the decrease in operating efficiency. Therefore, when operating the first isolation valve 61 and the second isolation valve 63, it is possible to prevent the valve from malfunctioning due to the biting of the slurry by performing the washing after injecting water. This allows proper valve operation and allows for more proper transfer of ore slurry.

The method is not limited to washing with water prior to the valve operation, and water may be sprayed onto the valve to wash the valve after the valve is operated to prevent the ore slurry from being caught.

Hereinafter, examples of the present invention will be described in more detail, but the present invention is not limited to the following examples.

The ore slurry was transferred to the high-pressure acid leaching facility 2 using the plant 1 (a plant having two series A series and B series) shown in FIG. 2 as a configuration example. Then, when the stirrer of the storage tank 11b and the electric motor of the storage tank 11b in the transfer facility 10B of the B series in the plant 1 failed and a trouble occurred that took a long time to recover, the operation was performed by the following operation.

Specifically, as shown in FIG. 3, the valves provided in the transfer pipes 12a and 12b of the transfer facilities 10A and 10B are controlled, and the ore slurry is controlled from the transfer facility 10A via the series connecting pipe 30. A part of the above was transferred to the high-pressure acid leaching facility 2B of the B series.

At the same time, the ore slurry prepared in the adjusting tank 40B corresponding to the B series is supplied to the storage tank 11a of the transfer facility 10A via the connecting pipe 42. That is, the ore slurry adjusted by the adjusting tank 40A and the ore slurry adjusted by the adjusting tank 40B are supplied and stored in the storage tank 11a of the transfer facility 10A in which no trouble has occurred. .. At this time, the stored amount of the ore slurry in the storage tank 11a, in other words, the transferred amount of the ore slurry transferred from the storage tank 11a is twice the normal amount.

Such an operation was carried out for two weeks from the completion of the repair work of the storage tank 11b to the restoration. Then, when the facility operating rate (flow load factor) of the high-pressure acid leaching facility 2 (2A, 2B) corresponding to each series during that period was calculated, the operation could be maintained at 100% of the normal operation. It was.

Table 1 below shows the actual capacity utilization rate. The equipment utilization rate in the conventional situation where the above-mentioned operation is not performed when a trouble occurs is also shown as a comparison.

1 Ore slurry transfer processing plant (plant)
2,2A, 2B High-pressure acid leaching equipment 10,10A, 10B Transfer equipment 11,11a, 11b Storage tank 12,12a, 12b Transfer pipe 21,21a, 21b Main pipe 22,22a, 22b Spare pipe 30 Series connection pipe 30e1, 30e2 (series connecting pipe) end 40, 40A, 40B Adjustment tank 41a, 41b Supply pipe 42 Connecting pipe 61, 61a, 61b First isolation valve 62, 62a, 62b Transfer pump 63, 63a, 63b Second Isolation valve

Claims (6)

An ore slurry transfer processing plant that transfers an ore slurry obtained by slurrying nickel oxide ore to a high-pressure acid leaching facility.
A storage tank for storing the ore slurry to be adjusted,
A first isolation valve, a transfer pump, and a second isolation valve are provided in this order from the upstream side to the downstream side through which the ore slurry flows, and the ore slurry supplied from the storage tank is subjected to the high pressure. Transfer piping to transfer to acid leaching equipment and
Equipped with two lines of transfer equipment
The transfer pipe in the transfer facility of each series is composed of a main pipe and a spare pipe, each of which is connected to the storage tank.
An ore slurry transfer processing plant in which the spare pipes are connected to each other by a series connection pipe at a position downstream of the transfer pump between the two series of transfer facilities. A claim in which the series connecting pipe is connected to the spare pipe in the transfer facility of each series at a position downstream of the transfer pump and at a position upstream of the second isolation valve. Item 2. The ore slurry transfer processing plant according to item 1. An adjustment tank for adjusting the ore slurry is connected to the storage tank in the transfer facility of each series.
The ore slurry transfer processing plant according to claim 1 or 2, wherein the ore slurry prepared in the adjustment tank of each series can be supplied to the storage tank in the transfer facility of each series. A method for operating an ore slurry transfer processing plant according to any one of claims 1 to 3.
During normal operation, the ore slurry supplied from the storage tank is transferred to the high-pressure acid leaching facility through the main pipe in the transfer pipe in the transfer equipment of each series.
When an abnormality occurs in any one of the two series of transfer equipment, the transfer equipment of the other series maintains the transfer of the ore slurry through the main pipe of the transfer pipe. A method for operating an ore slurry transfer processing plant that transfers the ore slurry from a spare pipe to the high-pressure acid leaching facility through the spare pipe of the one series via the series connecting pipe. If an abnormality occurs in the storage tank of any one of the two series of transfer equipment,
In the above-mentioned one series of transfer equipment,
The first isolation valve and the second isolation valve provided in the main pipe are closed, and the second isolation valve provided in the spare pipe is opened.
The method for operating an ore slurry transfer processing plant according to claim 4, wherein the ore slurry supplied from the transfer facility of the other series is transferred to the high-pressure acid leaching facility through the spare pipe via the series connecting pipe. The operation method of the ore slurry transfer processing plant according to claim 4 or 5, wherein the valve operation of the first isolation valve and the second isolation valve is performed after injecting water and washing with water.

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