Safety conveying process for slightly coarse-grained iron ore concentrate sharp-fall pipeline

Abstract

The invention relates to a safe conveying process for a sharp-fall pipeline of iron ore concentrate with slightly coarse granularity. The safe conveying process comprises the steps of establishing a head end station and a terminal station, conveying ore pulp from the head end station to the terminal station through a trunk pipeline and the like. Firstly, the station comprises a concentrate collection system, a concentration system and a pumping system, wherein the concentration system comprises an underflow facility; according to the method, the risk of pipeline blockage caused by too large particle size, long conveying distance, sharp fall and the like can be effectively avoided, the purpose of safely, efficiently and greenly conveying the iron ore concentrate is achieved, and therefore the industrial requirement for self-sufficiency of the iron ore concentrate is met.

Description

Technical Field

[0001] The present invention relates to the technical field of iron ore transportation, and in particular to a process for safely transporting relatively coarse-grained iron concentrate through a steep drop pipeline. Background Art

[0002] The iron ore concentrate of Nanfen Ore Dressing Plant has long been transported by rail. However, as the railway transportation capacity tends to be saturated, the problem of iron ore transportation has become increasingly prominent. In addition, the cost of railway transportation is relatively high. There are problems of waste of concentrate powder and dust pollution during transportation, which seriously restrict the production of upstream and downstream industries.

[0003] To address the transportation challenges of iron ore concentrate at the Nanfen Concentrator, improve its self-sufficiency rate, and enhance its market competitiveness, the plant conducted a technical and construction condition assessment for pipeline transportation of iron ore concentrate. The assessment concluded that pipeline transportation of iron ore concentrate at the Nanfen Concentrator is feasible. Pipeline transportation offers advantages such as energy conservation and environmental protection, low operating and maintenance costs, weather resistance, and safety and reliability.

[0004] Slurry pipeline transportation technology originated in coal transportation, but in recent years, pipeline transportation projects in other mineral resource sectors have developed rapidly worldwide. It is primarily used to transport various mineral materials such as iron ore concentrate, phosphate ore, and aluminum ore. Hundreds of large-scale, long-distance slurry pipelines have been built worldwide. Representative examples include the Black Messier Coal Pipeline in the United States, the Savage River Iron Concentrate Pipeline in Australia, the Samarco Iron Concentrate Pipeline in Brazil, the Shenwei Coal Pipeline in China, and the Dahongshan Iron Concentrate Pipeline in Yunnan.

[0005] The overall particle size of the iron ore concentrate at the Nanfen Ore Dressing Plant is relatively coarse, and the transportation distance to the terminal plate plant is long, with a sharp drop and a risk of blockage, making conventional pipeline transportation technology unsuitable. Summary of the Invention

[0006] In view of the above problems, the object of the present invention is to provide a process for safely transporting coarse-grained iron ore concentrate in a steep drop pipeline.

[0007] The technical solution adopted in the present invention is as follows: The present invention proposes a safe transportation process for coarse-grained iron ore concentrate using a steep drop pipeline, which specifically includes the following steps: S1. Establish the head-end station: including the concentrate collection system, concentration system and pumping system, of which the concentration system includes underflow facilities; The concentrate collection system includes three operating areas: red ore, three-five selection and four-selection; the concentration system includes a thickener and an underflow pump; the pumping system includes two stirring tanks, two feeding pumps, three diaphragm pumps, a test loop and a cleaning device; S2. Establish terminal station: Set up a comprehensive pump room and arrange the energy dissipation station, thickener underflow pump and mixing tank underflow pump together; S3. After being produced by the concentrator, the slurry enters the slurry pools of the red ore, three-five and four-selection operating areas, and is transported to the front-end collecting box through the slurry pumps installed in each operating area, and then transported to the concentration system. After the iron ore concentrate slurries of different concentrations in the three operating areas are collected in the thickener, the slurry is concentrated to a concentration of 63-68%, and transported to the buffer tank through the underflow pump. The feeding pump feeds the slurry in the buffer tank to the diaphragm pump through the test loop pipe, and finally transported to the terminal station through the trunk pipeline.

[0008] Furthermore, the feed port of the thickener is connected to the ore collecting box of the collection system, which collects the concentrates from each operating area, and the concentrated feed concentration is 36-38%; after being concentrated to a concentration of 63-68% by the thickener, the underflow is pumped to the head-end stirring tank through the underflow pump of the thickener, and the overflow flows to the process water pool.

[0009] Furthermore, the thickening system is provided with an independent slurry return pipeline. When the downstream system needs to be temporarily shut down, in order to avoid the accumulation of particles in the thickener and the resulting rake pressure accident, the thickener underflow is pumped to the inlet of the collection system for slurry circulation until the system resumes normal production.

[0010] Furthermore, the slurry pump is connected to the diaphragm pump through a pipeline, and a test loop is provided on the pipeline to confirm the characteristics of the first batch of slurry; a bypass branch is provided at the test loop, and unqualified slurry is returned to the mixing tank, thickener or head-end station accident pool; a filter with a mesh size of 6mm is provided at the outlet of each feeding pump to filter out debris, and the filter screen is cleaned and maintained regularly; the three diaphragm pumps are all driven by speed-regulating motors. Under normal circumstances, two are in use and one is in reserve. The three diaphragm pumps can also be operated in parallel to reduce component wear. When one of them needs maintenance, its speed will continue to decrease, while the speeds of the other two will automatically increase to compensate and maintain the set flow rate.

[0011] Furthermore, a process water adding point is set between the stirring tank and the feeding pump of the pumping system to adjust the slurry concentration. The qualified slurry concentration range is 63%~68%.

[0012] Furthermore, the outlet pipeline of each diaphragm pump is equipped with a slurry safety valve to protect the pump body and prevent overpressure in the main pipeline; the starting and ending ends of the main transmission pipeline are closed with flange blind plates. When cleaning is required, the blind plates are opened and the pipeline is descaled and cleaned by a pipeline scraper; each process pipeline is equipped with a flushing water outlet. When maintenance, process adjustment or long-term system shutdown is encountered, the residual slurry in the pipeline is flushed away to ensure that the pipeline is not blocked.

[0013] Furthermore, the headend station is equipped with a set of lime milk equipment and a set of sodium sulfite equipment, which are used to adjust the pH value and oxygen content in the slurry pipeline, alleviate corrosion in the pipeline, and protect the long-term stable operation of the slurry pipeline.

[0014] Furthermore, the feeding pump extracts the slurry from the stirring tank and feeds it to the main pipeline diaphragm pump, which then pumps it to the trunk pipeline and delivers it to the terminal station.

[0015] Furthermore, during normal production, the iron ore concentrate slurry with a concentration of 63% to 68% from the head-end station is dissipated at the terminal energy dissipation station, diluted in the pipeline system, and after the concentration is adjusted to 50%, it is transported to the ore separator in the filtration workshop, and then transferred to the ore separation box, and fed into the disc double vacuum filter for filtration and dehydration. The filtered iron ore concentrate powder is transported to the subsequent process links via a belt conveyor; the filtrate generated by the filtration of the iron ore concentrate slurry, and the low-concentration slurry at the head and tail of the slurry during batch transportation through pipelines are transported to the terminal thickener for concentration; the underflow slurry of the thickener is pressurized by the underflow pump of the thickener and transported to the filtration workshop for filtration and dehydration again to recover the iron concentrate; the overflow of the concentrator enters the water treatment system and is merged into the external drainage network after treatment.

[0016] Furthermore, two mixing tanks are installed at the terminal station. When the filter workshop stops temporarily, the mixing tank can receive the slurry from the main line, buffering the slurry transportation volume of the line for no less than 8 hours, thereby improving the continuity and stability of the transportation system operation; the slurry in the mixing tank is pressurized and transported by the mixing tank underflow pump, and after completion of dilution in the pipeline, it is fed into the filter workshop for filtration and dehydration.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Pipeline transportation has the advantages of energy saving and environmental protection, low operation and maintenance costs, no influence from weather, and safety and reliability.

[0018] 2. The project has been implemented at the Nanfen Ore Concentrator, generating significant economic and social benefits. The Nanfen iron ore concentrate pipeline transportation project operates safely and stably, with no pipeline blockages, cavitation, or other unsafe incidents. The slurry gradation, concentration, and flow rate have been optimized.

[0019] 3. By optimizing the existing grinding and classification process and researching anti-clogging methods, energy dissipation devices, and their calculation models, the team achieved an approximately 1% increase in metal recovery while effectively reducing the impurity content of the concentrate and ensuring the quality of the iron ore concentrate. This also enhanced the safety, stability, and efficiency of the pipeline system. Upon completion of the concentrate pipeline project, iron ore concentrate slurry can be transported via pipeline to a raw material base as far as 24.9 kilometers away, completely eliminating the impact of insufficient transportation capacity on steel production.

[0020] 4. The purpose of safe, efficient and green transportation of iron ore concentrate is achieved, thereby meeting the industrial demand for self-sufficiency of iron ore concentrate. The implementation of this invention can provide a reference basis for the selection and determination of the process flow of iron ore concentrate pipeline transportation in other units in the future, and has a high reference value for similar transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the head-end station of the present invention; Figure 2 It is a schematic diagram of the terminal station of the present invention. DETAILED DESCRIPTION

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] See attached Figures 1 and 2 The present invention proposes a safe transportation process for coarse-grained iron ore concentrate using a steep drop pipeline, which specifically includes the following steps: S1. Establish the head-end station: including the concentrate collection system, concentration system and pumping system, of which the concentration system includes underflow facilities; The concentrate collection system includes three operating areas: red ore, three-five selection and four-selection; the concentration system includes a thickener and an underflow pump; the pumping system includes two stirring tanks, two feeding pumps, three diaphragm pumps, a test loop and a cleaning device; S2. Establish terminal station: Set up a comprehensive pump room and arrange the energy dissipation station, thickener underflow pump and mixing tank underflow pump together; S3. After being produced by the concentrator, the slurry enters the slurry pools of the red ore, three-five and four-selection operating areas, and is transported to the front-end collecting box through three slurry pumps (one in use and two in reserve) installed in each operating area, and then transported to the concentration system. After the iron ore concentrate slurries of different concentrations in the three operating areas are collected in the thickener, the slurry is concentrated to a concentration of 63-68%, and transported to the buffer tank through the underflow pump. The feeding pump feeds the slurry in the buffer tank to the diaphragm pump through the test loop pipe, and finally transported to the terminal station through the trunk pipeline.

[0024] Specifically, the feed port of the thickener is connected to the ore collecting box of the collection system, which collects the concentrates from each operating area, and the concentrated feed concentration is 36-38%; after being concentrated to a concentration of 63-68% by the thickener, the underflow is pumped to the head-end stirring tank for stirring and storage through the underflow pump of the thickener (one in use and one in reserve), and the overflow liquid flows by gravity to the process water pool.

[0025] The slurry is extracted from the mixing tank and enters the feeding pump room, then fed to the main pipeline diaphragm pump in the main pump room, and then pumped to the terminal station.

[0026] In this embodiment, the thickening system is provided with an independent slurry return pipeline. When the downstream system needs to be temporarily shut down, in order to avoid the accumulation of particles in the thickener and the resulting rake pressure accident, the thickener underflow is pumped to the inlet of the collection system for slurry circulation until the system resumes normal production.

[0027] The slurry pump is connected to the diaphragm pump through a pipeline, and a test loop is provided on the pipeline to confirm the characteristics of the first batch of slurry. A bypass branch is provided at the test loop, and unqualified slurry is returned to the mixing tank, thickener or head-end station accident pool. A filter with a mesh size of 6mm is installed at the outlet of each feeding pump to filter out debris. The filter screen is cleaned and maintained regularly. The three diaphragm pumps are all driven by speed-regulating electric motors. Under normal circumstances, two are in use and one is in standby. The three diaphragm pumps can also be operated in parallel to reduce component wear. When one of them needs maintenance, its speed will continue to decrease, while the speed of the other two will automatically increase to compensate and maintain the set flow rate.

[0028] A process water addition point is set between the stirring tank and the feeding pump of the pumping system to adjust the slurry concentration. The qualified slurry concentration range is 63%~68%.

[0029] The outlet pipeline of each diaphragm pump is equipped with a slurry safety valve to protect the pump body and prevent overpressure in the main pipeline. The starting and ending ends of the main pipeline are closed with flange blind plates. When cleaning is required, the blind plates are opened and the pipeline is descaled and cleaned with a pipeline scraper. Each process pipeline is equipped with a flushing water outlet to flush away the residual slurry in the pipeline when maintenance, process adjustment or long-term system shutdown is required to ensure that the pipeline is not blocked.

[0030] The feeding pump draws slurry from the mixing tank and feeds it to the main pipeline diaphragm pump, which then pumps it to the trunk pipeline and delivers it to the terminal station.

[0031] In this embodiment, the headend station is equipped with a complete lime milk equipment system and a complete sodium sulfite equipment system to adjust the pH and oxygen content in the slurry pipeline, mitigate corrosion within the pipeline, and ensure long-term stable operation. The lime milk system primarily adjusts the slurry pH to approximately 10-11 to prevent acid corrosion during transportation. The lime milk dosing system primarily consists of a powder silo, a vibrating hopper, a feeder, a screw conveyor, a mixing tank, a liquid storage tank, and a screw pump. Three production lines (one for operation and two for backup) are used to prepare the lime milk solution. Slaked lime powder is pumped to the powder silo for storage via an air pump. During production, the powder is sequentially conveyed through a vibrating hopper, a feeder, and a screw conveyor to the mixing tank, where it is mixed with process water to create a lime milk solution. The lime milk solution is then collected by a transfer pump and stored in the liquid storage tank. During production, the prepared lime milk solution is pumped by a screw pump to the dosing point before the underflow pump in the concentration system to mix with the slurry. The sodium sulfite dosing system is primarily used for deoxygenation. The dosing point is located in the underflow pipe of the mixing tank in the feed pump room. During pipe flushing, sodium sulfite is added to reduce the oxygen content in the flushing water. The sodium sulfite dosing system consists of a dissolving tank and a metering pump. The system uses manual dosing, with sodium sulfite powder added to the dissolving tank in a proportional amount. After process water is added, the dissolving tank agitator stirs and dissolves the sodium sulfite. When flushing the pipe, the bottom valve of the dissolving tank is opened, and the metering pump is simultaneously activated for dosing.

[0032] During normal production, the iron ore concentrate slurry with a concentration of 63% to 68% from the head-end station is dissipated at the terminal energy dissipation station and diluted in the pipeline system. After the concentration is adjusted to about 50%, it is transported to the ore separator in the filtration workshop and then transferred to the ore separation box. It is fed into the disc double vacuum filter for filtration and dehydration. The filtered iron ore concentrate powder is transported to the subsequent process links via a belt conveyor; the filtrate generated by the filtration of the iron ore concentrate slurry and the low-concentration slurry at the head and tail of the slurry during batch transportation in pipelines are transported to the terminal thickener for concentration; the underflow slurry of the thickener is pressurized by the underflow pump of the thickener and transported to the filtration workshop for filtration and dehydration again to recover the iron concentrate; the overflow of the concentrator enters the water treatment system and is merged into the external drainage network after treatment.

[0033] Two mixing tanks are installed at the terminal station. When the filter workshop stops temporarily, the mixing tank can receive the slurry from the main line, buffering the slurry transportation volume of the line for no less than 8 hours, and improving the continuity and stability of the transportation system operation; the slurry in the mixing tank is pressurized and transported by the mixing tank underflow pump, and after dilution is completed in the pipeline, it is fed into the filter workshop for filtration and dehydration.

[0034] By studying the pipeline transportation characteristics and particle size control method of coarse-grained iron ore concentrate slurry, the present invention upgrades the grading equipment of the Nanfen Ore Dressing Plant, optimizes the process and parameters of iron ore concentrate pipeline transportation, and effectively reduces pipeline abrasion.

[0035] Matters not described in detail in this invention are all known technologies.

[0036] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A process for safely transporting coarse-grained iron ore concentrate in a steep drop pipeline, characterized in that: The method comprises the following steps: S1. Establish the head-end station: including the concentrate collection system, concentration system and pumping system, of which the concentration system includes underflow facilities; The concentrate collection system includes three operating areas: red ore, three-five selection and four-selection; the concentration system includes a thickener and an underflow pump; the pumping system includes two stirring tanks, two feeding pumps, three diaphragm pumps, a test loop and a cleaning device; S2. Establish terminal station: Set up a comprehensive pump room and arrange the energy dissipation station, thickener underflow pump and mixing tank underflow pump together; S3. After being produced by the concentrator, the slurry enters the slurry pools of the red ore, three-five and four-selection operating areas, and is transported to the front-end collecting box through the slurry pumps installed in each operating area, and then transported to the concentration system. After the iron ore concentrate slurries of different concentrations in the three operating areas are collected in the thickener, the slurry is concentrated to a concentration of 63-68%, and transported to the buffer tank through the underflow pump. The feeding pump feeds the slurry in the buffer tank to the diaphragm pump through the test loop pipe, and finally transported to the terminal station through the trunk pipeline.

2. The process for safely transporting coarse-grained iron ore concentrate through a steep drop pipeline according to claim 1, characterized in that: The feed inlet of the thickener is connected to the ore collecting box of the collection system, which collects the concentrates from each operating area, and the concentrated feed concentration is 36-38%. After being concentrated to a concentration of 63-68% by the thickener, the underflow is pumped to the head-end stirring tank through the underflow pump of the thickener, and the overflow flows to the process water pool by gravity.

3. The process for safely transporting coarse-grained iron ore concentrate through a steep drop pipeline according to claim 2, characterized in that: The thickening system is provided with an independent slurry return pipeline. When the downstream system needs to be temporarily shut down, in order to avoid the accumulation of particles in the thickener and the resulting rake pressure accident, the thickener underflow is pumped to the inlet of the collection system for slurry circulation until the system resumes normal production.

4. The process for safely transporting coarse-grained iron ore concentrate through a steep drop pipeline according to claim 2, characterized in that: The slurry pump is connected to the diaphragm pump through a pipeline, and a test loop is provided on the pipeline to confirm the characteristics of the first batch of slurry. A bypass branch is provided at the test loop, and unqualified slurry is returned to the mixing tank, thickener or head-end station accident pool. A filter with a mesh size of 6mm is installed at the outlet of each feeding pump to filter out debris. The filter screen is cleaned and maintained regularly. The three diaphragm pumps are all driven by speed-regulating electric motors. Under normal circumstances, two are in use and one is in standby. The three diaphragm pumps can also be operated in parallel to reduce component wear. When one of them needs maintenance, its speed will continue to decrease, while the speed of the other two will automatically increase to compensate and maintain the set flow rate.

5. The process for safely transporting relatively coarse-grained iron ore concentrate through a steep drop pipeline according to claim 4, characterized in that: A process water addition point is set between the stirring tank and the feeding pump of the pumping system to adjust the slurry concentration. The qualified slurry concentration range is 63%~68%.

6. The process for safely transporting coarse-grained iron ore concentrate through a steep drop pipeline according to claim 4, characterized in that: The outlet pipeline of each diaphragm pump is equipped with a slurry safety valve to protect the pump body and prevent overpressure in the main pipeline. The starting and ending ends of the main pipeline are closed with flange blind plates. When cleaning is required, the blind plates are opened and the pipeline is descaled and cleaned with a pipeline scraper. Each process pipeline is equipped with a flushing water outlet to flush away the residual slurry in the pipeline when maintenance, process adjustment or long-term system shutdown is required to ensure that the pipeline is not blocked.

7. The process for safely transporting coarse-grained iron ore concentrate through a steep drop pipeline according to claim 4, characterized in that: The headend station is equipped with one set of lime milk equipment and one set of sodium sulfite equipment, which are used to adjust the pH value and oxygen content in the slurry pipeline, alleviate corrosion in the pipeline, and protect the long-term stable operation of the slurry pipeline.

8. The process for safely transporting relatively coarse-grained iron ore concentrate through a steep drop pipeline according to claim 4, characterized in that: The feeding pump draws slurry from the mixing tank and feeds it to the main pipeline diaphragm pump, which then pumps it to the trunk pipeline and delivers it to the terminal station.

9. The process for safely transporting relatively coarse-grained iron ore concentrate through a steep drop pipeline according to claim 4, characterized in that: During normal production, the iron ore concentrate slurry with a concentration of 63% to 68% from the head-end station is dissipated at the terminal energy dissipation station and diluted in the pipeline system. After the concentration is adjusted to 50%, it is transported to the ore separator in the filtration workshop and then transferred to the ore separation box. It is fed into the disc double vacuum filter for filtration and dehydration. The filtered iron ore concentrate powder is transported to the subsequent process links via a belt conveyor. The filtrate generated by the iron ore concentrate slurry filtration and the low-concentration slurry at the head and tail of the pipeline during batch transportation are transported to the terminal thickener for concentration. The underflow slurry from the thickener is pressurized by the underflow pump of the thickener and transported to the filtration workshop for further filtration and dehydration to recover the iron ore concentrate. The overflow from the concentrator enters the water treatment system and is then incorporated into the external drainage network after treatment.

10. The process for safely transporting coarse-grained iron ore concentrate through a steep drop pipeline according to claim 9, characterized in that: Two mixing tanks are installed at the terminal station. When the filter workshop stops temporarily, the mixing tank can receive the slurry from the main line, buffering the slurry transportation volume of the line for no less than 8 hours, and improving the continuity and stability of the transportation system operation; the slurry in the mixing tank is pressurized and transported by the mixing tank underflow pump, and after dilution is completed in the pipeline, it is fed into the filter workshop for filtration and dehydration.

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