Safe conveying process of coarse-grained iron ore concentrate through free-fall differential pipe

Abstract

The present application relates to a kind of coarse particle size iron ore concentrate sudden drop difference pipeline safe conveying process, including the establishment of first end station, terminal station and ore pulp is transported to terminal station by first end station through trunk pipeline etc.;First station includes concentrate collection system, concentration system and pump delivery system, wherein concentration system contains underflow facility;The present application can effectively avoid the risk of pipeline blockage caused by coarse particle size, long conveying distance, sudden drop difference etc.;Realize the purpose of safe, efficient, green conveying iron concentrate, so as to meet the self-sufficient industry demand of iron concentrate.

Description

Technical Field

[0001] This invention relates to the field of iron ore transportation technology, and in particular to a safe pipeline transportation process for coarse-grained iron concentrate with a rapid drop. Background Technology

[0002] The transportation of iron concentrate at Nanfen Ore Processing Plant has long relied on railway transportation. However, as railway capacity approaches saturation, the problem of iron concentrate transportation has become increasingly prominent. In addition, railway transportation costs are high, and there are problems such as concentrate powder spillage and waste, and dust pollution during transportation, which seriously restrict the production of upstream and downstream industries.

[0003] To address the transportation issues of iron concentrate at the Nanfen Iron Ore Concentrator, improve its self-sufficiency rate, and enhance its market competitiveness, the Nanfen Iron Ore Concentrator conducted a technical and construction condition assessment of iron concentrate pipeline transportation. The assessment concluded that pipeline transportation of iron concentrate at the Nanfen Iron Ore Concentrator is feasible. Furthermore, pipeline transportation offers advantages such as energy conservation and environmental protection, low operation and maintenance costs, immunity to weather conditions, and safety and reliability.

[0004] Slurry pipeline transportation technology originated from coal transportation, but in recent years it has developed rapidly in pipeline transportation projects for other mineral resources worldwide, mainly for transporting various ores such as iron ore concentrate, phosphate rock, and aluminum ore. There are hundreds of large-scale, long-distance slurry pipelines already built worldwide. Representative slurry pipelines include the Black Mesa coal pipeline in the United States, the Savage River iron ore pipeline in Australia, the Samarco iron ore pipeline in Brazil, and the Shenwei coal pipeline and the Yunnan Dahongshan iron ore pipeline in China.

[0005] The iron concentrate from Nanfen Beneficiation Plant has a generally coarse particle size, and the transportation distance to the terminal plate processing plant is long with a steep drop, posing a risk of blockage and making conventional pipeline transportation processes unsuitable. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a safe pipeline transportation process for coarse-grained iron concentrate with rapid drop.

[0007] The technical solution adopted in this invention is as follows: The present invention proposes a safe pipeline transportation process for coarse-grained iron concentrate with rapid drop, which specifically includes the following steps: S1. Establish the initial station: including a concentrate collection system, a thickening system and a pumping system, wherein the thickening system contains underflow facilities; The concentrate collection system includes three working areas: red ore, three- and five-stage beneficiation, and four-stage beneficiation; the thickening system includes a thickener and an underflow pump; the pumping system includes two mixing tanks, two feed pumps, three diaphragm pumps, a test loop, and a cleaning device. S2. Establish terminal stations: Set up integrated pump rooms to combine the energy dissipation station, thickener underflow pump and mixing tank underflow pump; S3. After being processed by the concentrator, the slurry enters the slurry pools of the three working areas: red ore, third- and fifth-stage concentrators, and fourth-stage concentrator. It is then transported to the front-end collection box by the slurry pumps set up in each working area, and then to the thickening system. The iron concentrate slurries of different concentrations from the three working areas are collected in the thickener, where the slurry is concentrated to a concentration of 63-68%. It is then transported to the buffer tank by the underflow pump. The feed pump feeds the slurry in the buffer tank to the diaphragm pump through the test loop pipe, and finally transports it to the terminal station through the main pipeline.

[0008] Furthermore, the feed inlet of the thickener is connected to the ore collection box of the collection system. The ore collection box collects the concentrate from each working area, and the concentration of the feed is 36-38%. After being concentrated to a concentration of 63-68% by the thickener, the underflow is pumped to the first-end mixing tank by the thickener underflow pump, and the overflow flows by gravity to the process water tank.

[0009] Furthermore, the thickening system is equipped with an independent return slurry pipeline. When the downstream system needs to be temporarily shut down, in order to avoid particle deposition in the thickener and cause a rake accident, the underflow from the thickener is pumped to the inlet of the collection system for slurry circulation until the system resumes normal production.

[0010] Furthermore, the slurry pump and the diaphragm pump are connected by a pipeline, and a test loop is installed on the pipeline to confirm the characteristics of the first batch of slurry. A bypass branch is installed at the test loop, and unqualified slurry is returned to the mixing tank, thickener, or emergency pool at the first-end station. Each feed pump outlet is equipped with a 6mm mesh filter to filter out impurities, and the filter screen is cleaned and maintained regularly. All three diaphragm pumps are driven by variable speed motors. Under normal circumstances, two are in use and one is on standby. The three diaphragm pumps can also be operated in parallel to reduce component wear. When one of them needs maintenance, its speed will continuously decrease, while the speeds of the other two will automatically increase to compensate and maintain the set flow rate.

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

[0012] Furthermore, each diaphragm pump's outlet pipeline is equipped with a slurry safety valve to protect the pump body and prevent overpressure in the main pipeline; the beginning and end points of the main conveying pipeline are sealed with flange blind plates. When cleaning is required, the blind plates are opened, and the pipeline is cleaned by a pipeline scraper; each process pipeline is equipped with a flushing port to flush away residual slurry in the pipeline during maintenance, process adjustments, or long-term system shutdowns, ensuring that the pipeline does not become blocked.

[0013] Furthermore, the initial station is equipped with one set of lime slurry 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.

[0014] Furthermore, 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.

[0015] Furthermore, during normal production, the iron concentrate slurry with a concentration of 63%–68% from the initial 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 separator in the filtration workshop and then transferred to the sorting box. It is then fed into the disc double vacuum filter for filtration and dewatering. The filtered iron concentrate powder is transferred to the subsequent process stages via belt conveyor. The filtrate produced by the iron concentrate slurry filtration, as well as the low-concentration slurry from the slurry head and tail during the batch pipeline transportation, are transported to the terminal thickener for concentration. The underflow slurry from the thickener is pressurized and transported to the filtration workshop by the thickener underflow pump for further filtration and dewatering to recover the iron concentrate. The overflow from the thickener enters the water treatment system, is treated, and then connected to the external drainage network.

[0016] Furthermore, the terminal station is equipped with two mixing tanks. When the filtration workshop is temporarily shut down, the mixing tanks can receive slurry from the main line and buffer the slurry transport volume of the line for no less than 8 hours, thereby improving the continuity and stability of the transport system. The slurry in the mixing tank is pressurized and transported by the bottom flow pump of the mixing tank. After being diluted in the pipeline, it is then fed into the filtration workshop for filtration and dewatering.

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

[0018] 2. The project has been successfully implemented at the Nanfen ore beneficiation plant, generating significant economic and social benefits. The Nanfen iron concentrate pipeline transportation project has operated safely and stably, without any pipeline blockages, cavitation, or other unsafe incidents. The slurry gradation, slurry concentration, and transport 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 metal recovery rate was increased by approximately 1% while effectively reducing the impurity content of the concentrate and ensuring the grade of the iron concentrate. This also improved the safety, stability, and efficiency of the pipeline transportation system. After the completion of the concentrate pipeline project, iron concentrate slurry can be transported via pipeline to the raw material base located 24.9 kilometers away, completely eliminating the impact of insufficient transportation capacity on steel production.

[0020] 4. This invention achieves the goal of safe, efficient, and environmentally friendly transportation of iron concentrate, thereby meeting the industry's self-sufficiency needs for iron concentrate. The implementation of this invention can provide a reference for the selection and determination of pipeline transportation processes for other units in the future, and has high reference value for similar modifications. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the first terminal station of the present invention; Figure 2 This is a schematic diagram of the terminal station of the present invention. Detailed Implementation

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] See appendix Figures 1-2 The present invention proposes a safe pipeline transportation process for coarse-grained iron concentrate with a rapid drop, which specifically includes the following steps: S1. Establish the initial station: including a concentrate collection system, a thickening system and a pumping system, wherein the thickening system contains underflow facilities; The concentrate collection system includes three working areas: red ore, three- and five-stage beneficiation, and four-stage beneficiation; the thickening system includes a thickener and an underflow pump; the pumping system includes two mixing tanks, two feed pumps, three diaphragm pumps, a test loop, and a cleaning device. S2. Establish terminal stations: Set up integrated pump rooms to combine the energy dissipation station, thickener underflow pump and mixing tank underflow pump; S3. After being processed by the concentrator, the slurry enters the slurry pools of the three working areas: red ore, third- and fifth-stage concentrators, and fourth-stage concentrator. It is then transported to the front-end collection box by three slurry pumps (one in use and two on standby) set up in each working area, and then to the thickening system. The iron concentrate slurries of different concentrations from the three working areas are collected in the thickener and concentrated to a concentration of 63-68%. The slurry is then transported to the buffer tank by the underflow pump. The feed pump feeds the slurry in the buffer tank to the diaphragm pump through the test loop pipe, and finally transports it to the terminal station through the main pipeline.

[0024] Specifically, the feed inlet of the thickener is connected to the collection box of the collection system. The collection box collects the concentrate from each working area, and the concentration of the feed is 36-38%. After being concentrated to a concentration of 63-68% by the thickener, the underflow is pumped to the first-end mixing tank for mixing and storage by the thickener underflow pump (one in use and one in standby). The overflow liquid flows by gravity to the process water tank.

[0025] The slurry is drawn from the mixing tank and fed into the feeding pump room. The slurry is 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 equipped with an independent return slurry pipeline. When the downstream system needs to be temporarily shut down, in order to avoid particle deposition in the thickener and cause a rake accident, the underflow of the thickener is pumped to the inlet of the collection system for slurry circulation until the system resumes normal production.

[0027] The slurry pump and diaphragm pump are connected by pipelines, and a test loop is installed on the pipelines to confirm the characteristics of the first batch of slurry. A bypass branch is installed at the test loop, and unqualified slurry is returned to the mixing tank, thickener, or emergency pool at the first-end station. Each feed pump outlet is equipped with a 6mm mesh filter to filter out impurities. The filter screens are cleaned and maintained regularly. All three diaphragm pumps are driven by variable speed motors. Under normal circumstances, two are in operation and one is on standby. The three diaphragm pumps can also be operated in parallel to reduce component wear. When one of them needs maintenance, its speed will be continuously reduced, while the speeds 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 mixing tank and the feeding pump of the pumping system to adjust the slurry concentration. The qualified slurry concentration range is 63%~68%.

[0029] Each diaphragm pump's outlet pipeline is equipped with a slurry safety valve to protect the pump body and prevent overpressure in the main pipeline. The beginning and end points of the main pipeline are sealed with flange blind plates. When cleaning is required, the blind plates are opened, and the pipeline is cleaned by a pipeline scraper. Each process pipeline is equipped with a flushing port. When maintenance, process adjustment, or long-term system shutdown occurs, residual slurry in the pipeline is flushed away to ensure that the pipeline does not become blocked.

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

[0031] In this embodiment, the initial station is equipped with one set of lime slurry equipment and one set of sodium sulfite equipment. These are used to adjust the pH and oxygen content in the slurry pipeline, alleviate corrosion, and protect the long-term stable operation of the slurry pipeline. The lime slurry system is mainly used to adjust the slurry pH to around 10-11 to prevent acid corrosion during transportation. The lime slurry dosing system mainly consists of a powder silo, a vibrating hopper, a feeder, a screw conveyor, a mixing tank, a storage tank, and a screw pump. Three production lines (one in operation and two on standby) are set up for lime slurry solution preparation. Quicklime powder is pumped to the powder silo for storage via an air pump. During production, the powder is sequentially transported through the vibrating hopper, feeder, and screw conveyor to the mixing tank to mix with process water, preparing a lime slurry solution. The lime slurry solution is then collected in the storage tank via a transfer pump. During production, the prepared lime slurry solution is pumped to the dosing point before the underflow pump of the thickening system via a screw pump to mix with the slurry. The sodium sulfite dosing system is primarily used for deoxygenation. The dosing point is located in the underflow pipeline of the mixing tank in the feed pump room. Sodium sulfite is added to reduce the oxygen content in the flushing water during pipeline flushing. The sodium sulfite dosing system consists of a dissolving tank and a metering pump. The system uses manual feeding; sodium sulfite powder is added to the dissolving tank in a specific ratio, followed by process water, and then dissolved by the tank's agitator. During pipeline flushing, the valve at the bottom of the dissolving tank is opened, and the metering pump is simultaneously activated for dosing.

[0032] During normal production, iron concentrate slurry with a concentration of 63% to 68% from the initial 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 separator in the filtration workshop and then transferred to the sorting box. It is then fed into the disc double vacuum filter for filtration and dewatering. The filtered iron concentrate powder is transferred to the subsequent process stages by belt conveyor. The filtrate produced by the iron concentrate slurry filtration, as well as the low-concentration slurry from the slurry head and tail during the batch pipeline transportation, are transported to the terminal thickener for concentration. The underflow slurry from the thickener is pressurized and transported to the filtration workshop for filtration and dewatering again to recover the iron concentrate. The overflow from the thickener enters the water treatment system, is treated, and then connected to the external drainage network.

[0033] The terminal station is equipped with two mixing tanks. When the filtration workshop is temporarily shut down, the mixing tanks can receive slurry from the main line and buffer the slurry transport volume of the line for no less than 8 hours, thereby improving the continuity and stability of the transport system. The slurry in the mixing tank is pressurized and transported by the bottom flow pump of the mixing tank. After being diluted in the pipeline, it is then fed into the filtration workshop for filtration and dewatering.

[0034] This invention, through research on the pipeline transportation characteristics and particle size control methods of coarse-grained iron concentrate slurry, upgraded the classification equipment of Nanfen concentrator, optimized the process and parameters of iron concentrate pipeline transportation, and effectively reduced pipeline erosion.

[0035] All matters not covered in this invention are common knowledge.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A safe pipeline transportation process for coarse-grained iron concentrate with a rapid drop, characterized in that, The process includes the following steps: S1. Establish the initial station: including a concentrate collection system, a thickening system and a pumping system, wherein the thickening system contains underflow facilities; The concentrate collection system includes three working areas: red ore, three- and five-stage beneficiation, and four-stage beneficiation; the thickening system includes a thickener and an underflow pump; the pumping system includes two mixing tanks, two feed pumps, three diaphragm pumps, a test loop, and a cleaning device. S2. Establish terminal stations: Set up integrated pump rooms to combine the energy dissipation station, thickener underflow pump and mixing tank underflow pump; S3. After being processed by the concentrator, the slurry enters the slurry pools of the three working areas of red ore, three-five beneficiation and four beneficiation. It is then transported to the front-end collection box by the slurry pump set in each working area, and then to the thickening system. The iron concentrate slurries of different concentrations in the three working areas are collected in the thickener and the slurry is concentrated to a concentration of 63-68%. It is then transported to the buffer tank by the underflow pump. The feed pump feeds the slurry in the buffer tank to the diaphragm pump through the test loop pipe, and finally transports it to the terminal station through the main pipeline. The feed inlet of the thickener is connected to the collection box of the collection system. The collection box collects the concentrate from each working area and the concentration of the feed is 36-38%. After being concentrated to a concentration of 63-68% by the thickener, the underflow is pumped to the first-end mixing tank by the thickener underflow pump, and the overflow flows by gravity to the process water tank. The slurry pump and diaphragm pump are connected by a pipeline, and a test loop is installed on the pipeline to confirm the characteristics of the first batch of slurry. A bypass branch is installed at the test loop to return unqualified slurry to the mixing tank, thickener, or emergency pool at the first-end station. Each feed pump has a 6mm mesh filter at its outlet to filter out impurities. The filter screen is cleaned and maintained regularly. All three diaphragm pumps are driven by variable speed motors. Under normal circumstances, two of the three diaphragm pumps are in use and one is on standby, or they are operated in parallel to reduce wear on components. When one of them needs maintenance, its speed will continuously decrease, while the speeds of the other two will automatically increase to compensate and maintain the set flow rate. During normal production, iron concentrate slurry with a concentration of 63%–68% from the initial plant 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 separator in the filtration workshop and then transferred to the sorting box. It is then fed into a disc double vacuum filter for filtration and dewatering. The filtered iron concentrate powder is transferred to the subsequent process stages via belt conveyor. The filtrate produced by the iron concentrate slurry filtration, as well as the low-concentration slurry from the slurry head and tail during the batch pipeline transportation, are transported to the terminal thickener for concentration. The underflow slurry from the thickener is pressurized and transported to the filtration workshop for further filtration and dewatering to recover the iron concentrate. The overflow from the thickener enters the water treatment system, is treated, and then connected to the external drainage network.

2. The safe pipeline transportation process for coarse-grained iron concentrate with rapid drop as described in claim 1, characterized in that: The thickening system is equipped with an independent return pipeline. When the downstream system needs to be temporarily shut down, in order to avoid particle deposition in the thickener and causing a rake accident, the underflow of the thickener is pumped to the inlet of the collection system for slurry circulation until the system resumes normal production.

3. The safe pipeline transportation process for coarse-grained iron concentrate with rapid drop as described in claim 1, characterized in that: A process water addition point is set between the mixing tank and the feeding pump of the pumping system to adjust the slurry concentration. The qualified slurry concentration range is 63%~68%.

4. The safe pipeline transportation process for coarse-grained iron concentrate with rapid drop as described in claim 1, characterized in that: Each diaphragm pump's outlet pipeline is equipped with a slurry safety valve to protect the pump body and prevent overpressure in the main pipeline. The beginning and end points of the main pipeline are sealed with flange blind plates. When cleaning is required, the blind plates are opened, and the pipeline is cleaned by a pipeline scraper. Each process pipeline is equipped with a flushing port. When maintenance, process adjustment, or long-term system shutdown occurs, residual slurry in the pipeline is flushed away to ensure that the pipeline does not become blocked.

5. The safe pipeline transportation process for coarse-grained iron concentrate with rapid drop as described in claim 1, characterized in that: The initial station is equipped with one set of lime slurry 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.

6. The safe pipeline transportation process for coarse-grained iron concentrate with rapid drop as described in claim 1, characterized in that: The feeding pump draws slurry from the mixing tank and feeds it to the diaphragm pump in the main pipeline, which then pumps it to the trunk pipeline and delivers it to the terminal station.

7. The safe pipeline transportation process for coarse-grained iron concentrate with rapid drop as described in claim 1, characterized in that: The terminal station is equipped with two mixing tanks. When the filtration workshop is temporarily shut down, the mixing tanks can receive slurry from the main line and buffer the slurry transport volume of the line for no less than 8 hours, thereby improving the continuity and stability of the transport system. The slurry in the mixing tank is pressurized and transported by the bottom flow pump of the mixing tank. After being diluted in the pipeline, it is then fed into the filtration workshop for filtration and dewatering.

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