Iron tailing recycling and recleaning process

Abstract

The invention provides an iron tailing recycling and recleaning process which comprises the following steps: feeding and crushing: feeding iron tailings into a crushing mechanism and screening until the diameter of finally fed powder particles is not more than 2mm; the obtained powder particles are fed into a dewatering and drying device to be dewatered and preheated, and dried powder is obtained; feeding the obtained dry powder into a magnetic separation device, and screening to obtain primary fine magnetic mineral powder and secondary mineral powder; the obtained secondary mineral powder is fed into a drug reaction kettle for drug reaction to obtain prepared ore pulp, the obtained secondary mineral powder is fed into a standby area, the obtained prepared ore pulp is fed into a roasting reaction kettle for reaction and drying, carbon powder and hydrogen are added into the roasting reaction kettle, and the prepared ore pulp is obtained. And dry ore blocks are obtained under the initial state of the roasting reaction kettle and the mass ratio of the internal oxygen to the mineral powder is not more than 4: 3, the dry ore blocks are fed into a grinding mechanism to be ground into prepared mineral powder with the particle diameter not more than 2 mm, and the prepared mineral powder is fed into a magnetic separation device to be screened to obtain secondary fine magnetic mineral powder and tailing slag.

Description

Technical Field

[0001] The invention relates to the technical field of iron tailings recovery and reselection, and in particular to an iron tailings recovery and reselection process. Background Art

[0002] Iron tailings are waste after ore dressing and are the main component of industrial solid waste. According to incomplete statistics, more than 10 billion tons of tailings and waste rock are discharged worldwide each year.

[0003] Tailings are tailings that can be utilized by sand making machines and sand making equipment under specific economic and technical conditions in the ore dressing plant. The solid waste discharged after the ore is ground and the useful components are selected is an important source of environmental pollution caused by mining development, especially metal mining development. Discarding tailings not only requires a large amount of land and causes great harm to the surrounding ecological environment, but also requires investment in respective processing and maintenance costs. The comprehensive recovery and utilization of tailings resources can not only make full use of mineral resources, expand the scope of mineral resource utilization, and extend the service life of mines; it is also an important means of pollution control and ecological protection; it can also save a lot of land and funds, solve employment problems, benefit human society, and achieve the effective unity of resource benefits, economic benefits, social benefits and environmental benefits. After years of research, tailings have been used in the production of building materials and machine-made sand.

[0004] The existing treatment methods for iron tailings are mainly to apply them to wastewater treatment applications, or to use roasting or chemical treatment. The treatment methods are single, the equipment linkage is poor, and the tailings utilization rate is low. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an iron tailings recovery and reselection process, which is implemented as follows:

[0006] An iron tailings recovery and reselection process comprises the following steps:

[0007] S1. Feeding and crushing, feeding the iron tailings into the crushing mechanism and screening until the diameter of the final powder particles does not exceed 2mm;

[0008] S2. The powder particles obtained by S1 are sent to a dehydration and drying device for dehydration and preheating to obtain a dry powder;

[0009] S3. The dry powder obtained by S2 is sent to a magnetic separation device for screening to obtain primary fine magnetic ore powder and secondary ore powder;

[0010] S4. The secondary ore powder obtained by S3 is fed into a drug reactor for drug reaction to obtain a prepared slurry, and the prepared slurry obtained by S3 is fed into a standby area;

[0011] S5. The prepared ore pulp obtained by S4 is sent to a roasting reactor for reaction and drying, carbon powder and hydrogen are added to the roasting reactor, and the ratio of the internal oxygen mass to the ore powder mass in the initial state of the roasting reactor does not exceed 4:3 to obtain dry ore blocks, and the dry ore blocks are sent to a grinding mechanism to be ground into prepared ore powder with a particle diameter not exceeding 2 mm, and the prepared ore powder is sent to a magnetic separation device for screening to obtain secondary fine magnetic ore powder and tailings.

[0012] As a further improvement, the crushing mechanism includes at least three crushers, the crushing fineness of the crushers increases from top to bottom, and each crusher is arranged in sequence according to the left and right intervals, and two adjacent crushers are connected by a feeding conveyor belt, and the feeding conveyor belt is provided with mesh holes, and the feeding conveyor belt vibrates at a frequency of 15 to 50 Hz. The bottom layer of the crushing mechanism is provided with a screening conveyor belt with a mesh hole of 2 mm. The powder particles crushed by the last stage crusher fall onto the screening conveyor belt for screening, and the powder particles that fail to pass the screening are sent to the lifting device by the screening conveyor belt to be fed again from the feed port;

[0013] The conveyor belt width of the feeding conveyor belt is widened toward both sides from top to bottom in sequence, and the width difference between two adjacent feeding conveyor belts is 20% to 50%.

[0014] As a further improvement, the S2 specifically includes the following steps:

[0015] S201. Preheating: the powder particles are fed into the dehydration and drying device for 30 minutes, 120°C to 180°C, and a negative pressure of 8 to 12Kpa;

[0016] S202. Heating, heating in the dehydration drying device for 5 min, 220 to 260 ° C, negative pressure 3 to 5 Kpa;

[0017] S203. Discharging the dried powder into a cooling area until the temperature drops to 80-120°C.

[0018] As a further improvement, a blast device is provided in the dehydration and drying device, which is connected to the tail gas pipeline of the roasting reactor. The blast device passes the high-temperature flue gas discharged from the roasting reactor into the dehydration and drying device as a preheating heat source.

[0019] As a further improvement, a flue gas treatment device is provided at the smoke outlet of the dehydration and drying device, and the flue gas treatment device includes a denitration reactor, a bag filter, and a desulfurization tower.

[0020] As a further improvement, S4 specifically includes adding an additive and stirring and mixing, the stirring time is not less than 10 minutes, and the added agents are oxidized paraffin soap and water glass agent.

[0021] As a further improvement, the reaction temperature in the roasting reactor is 650-750° C., and the reaction time is 45-90 min.

[0022] The beneficial effects of the present invention are:

[0023] First, the iron-containing tailings powder that is easy to screen is screened out through grinding and beneficiation, and then the secondary ore powder is added with reagents to react with the ore powder that is difficult to be selected by the magnetic separator, and then secondary beneficiation is carried out, which makes full use of the residual iron elements in the tailings and reduces waste and pollution. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention.

[0025] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0026] An iron tailings recovery and reselection process comprises the following steps:

[0027] S1. Feeding and crushing, feeding the iron tailings into the crushing mechanism and screening until the diameter of the final powder particles does not exceed 2mm;

[0028] Specifically, the diameter of the powder particles is usually 0.8-2 mm, so the particle size of the powder particles finally fed can be limited to no more than 1.5 mm, no more than 1 mm or no more than 0.8 mm according to the specific type or variety of tailings.

[0029] S2. If the particle size of the material particles is limited to no more than 1.5 mm or no more than 2 mm in S1, the powder particles obtained by S1 are sent to a dehydration and drying device for dehydration and preheating to obtain dry powder. If the particle size of the material particles is limited to no more than 1 mm or 0.8 mm in S1, pulping is directly performed, and the pulping process is the same as step S4;

[0030] S3. The dry powder obtained by S2 is sent to a magnetic separation device for screening to obtain primary fine magnetic ore powder and secondary ore powder;

[0031] S4. The secondary ore powder obtained by S3 is fed into a drug reactor for drug reaction to obtain a prepared slurry, and the prepared slurry obtained by S3 is fed into a standby area;

[0032] S5. The prepared ore pulp obtained by S4 is sent to a roasting reactor for reaction and drying, carbon powder and hydrogen are added to the roasting reactor, and the ratio of the internal oxygen mass to the ore powder mass in the initial state of the roasting reactor does not exceed 4:3 to obtain dry ore blocks, and the dry ore blocks are sent to a grinding mechanism to be ground into prepared ore powder with a particle diameter not exceeding 2 mm, and the prepared ore powder is sent to a magnetic separation device for screening to obtain secondary fine magnetic ore powder and tailings.

[0033] As a further improvement, the crushing mechanism includes at least three crushers, the crushing fineness of the crushers increases from top to bottom, and each crusher is arranged in sequence according to the left and right intervals, and two adjacent crushers are connected by a feeding conveyor belt, and the feeding conveyor belt is provided with mesh holes, and the feeding conveyor belt vibrates at a frequency of 15 to 50 Hz. The bottom layer of the crushing mechanism is provided with a screening conveyor belt with a mesh hole of 2 mm. The powder particles crushed by the last stage crusher fall onto the screening conveyor belt for screening, and the powder particles that fail to pass the screening are sent to the lifting device by the screening conveyor belt to be fed again from the feed port;

[0034] The conveyor belt width of the feeding conveyor belt is widened toward both sides from top to bottom in sequence, and the width difference between two adjacent feeding conveyor belts is 20% to 50%.

[0035] As a further improvement, the S2 specifically includes the following steps:

[0036] S201. Preheating: the powder particles are fed into the dehydration and drying device for 30 minutes, 120°C to 180°C, and a negative pressure of 8 to 12Kpa;

[0037] S202. Heating, heating in the dehydration drying device for 5 min, 220 to 260 ° C, negative pressure 3 to 5 Kpa;

[0038] S203. Discharging the dried powder into a cooling area until the temperature drops to 80-120°C.

[0039] As a further improvement, a blast device is provided in the dehydration and drying device, which is connected to the tail gas pipeline of the roasting reactor. The blast device passes the high-temperature flue gas discharged from the roasting reactor into the dehydration and drying device as a preheating heat source.

[0040] As a further improvement, a flue gas treatment device is provided at the smoke outlet of the dehydration and drying device, and the flue gas treatment device includes a denitration reactor, a bag filter, and a desulfurization tower.

[0041] As a further improvement, S4 specifically includes adding an additive and stirring and mixing, the stirring time is not less than 10 minutes, and the added agents are oxidized paraffin soap and water glass agent.

[0042] As a further improvement, the reaction temperature in the roasting reactor is 650-750° C., and the reaction time is 45-90 min.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An iron tailings recovery and reselection process, characterized in that: The following steps are involved: S1. Feeding and crushing, feeding the iron tailings into the crushing mechanism and screening until the diameter of the final powder particles does not exceed 2mm; S2. The powder particles obtained by S1 are sent to a dehydration and drying device for dehydration and preheating to obtain a dry powder; S3. The dry powder obtained by S2 is sent to a magnetic separation device for screening to obtain primary fine magnetic ore powder and secondary ore powder; S4. The secondary ore powder obtained by S3 is fed into a drug reactor for drug reaction to obtain a prepared slurry, and the prepared slurry obtained by S3 is fed into a standby area; S5. The prepared ore pulp obtained by S4 is sent to a roasting reactor for reaction and drying, carbon powder and hydrogen are added to the roasting reactor, and the ratio of the internal oxygen mass to the ore powder mass in the initial state of the roasting reactor does not exceed 4:3 to obtain dry ore blocks, and the dry ore blocks are sent to a grinding mechanism to be ground into prepared ore powder with a particle diameter not exceeding 2 mm, and the prepared ore powder is sent to a magnetic separation device for screening to obtain secondary fine magnetic ore powder and tailings.

2. The iron tailings recovery and reselection process according to claim 1, characterized in that: The crushing mechanism includes at least three crushers, the crushing fineness of the crushers increases from top to bottom, and each crusher is arranged in sequence according to the left and right intervals. Two adjacent crushers are connected by a feeding conveyor belt, and the feeding conveyor belt is provided with mesh holes, and the feeding conveyor belt vibrates at a frequency of 15 to 50 Hz. The bottom layer of the crushing mechanism is provided with a screening conveyor belt with a mesh hole of 2 mm. The powder particles crushed by the last stage crusher fall onto the screening conveyor belt for screening, and the powder particles that fail to pass the screening are sent to the lifting device by the screening conveyor belt to be fed again from the feed port; The conveyor belt width of the feeding conveyor belt is widened toward both sides from top to bottom in sequence, and the width difference between two adjacent feeding conveyor belts is 20% to 50%.

3. The iron tailings recovery and reselection process according to claim 1, characterized in that: The S2 specifically includes the following steps: S201. Preheating: the powder particles are fed into the dehydration and drying device for 30 minutes, 120°C to 180°C, and a negative pressure of 8 to 12Kpa; S202. Heating, heating in the dehydration drying device for 5 min, 220 to 260 ° C, negative pressure 3 to 5 Kpa; S203. Discharging the dried powder into a cooling area until the temperature drops to 80-120°C.

4. The iron tailings recovery and reselection process as claimed in claim 3, characterized in that: The dehydration and drying device is provided with a blast device, which is connected to the tail gas pipeline of the roasting reactor. The blast device passes the high-temperature flue gas discharged from the roasting reactor into the dehydration and drying device as a preheating heat source.

5. The iron tailings recovery and reselection process as claimed in claim 4, characterized in that: A flue gas treatment device is arranged at the smoke outlet of the dehydration and drying device, and the flue gas treatment device includes a denitration reactor, a bag filter and a desulfurization tower.

6. The iron tailings recovery and reselection process according to claim 1, characterized in that: The S4 specifically includes adding an additive and stirring and mixing, the stirring time is not less than 10 minutes, and the added agents are oxidized paraffin soap and water glass agent.

7. The iron tailings recovery and reselection process according to claim 1, characterized in that: The reaction temperature in the roasting reactor is 650-750° C., and the reaction time is 45-90 minutes.