Iron and Steel Plant Sintering Machine Head Ash Separation Process

Abstract

The present invention relates to the technical field of mineral processing, and proposes a sorting process for sintering machine head ash in a steel plant, which includes the following technological processes: Materials are put into a silo and enter a crushing device through a feeder for crushing; The crushed materials are fed into a flotation machine to select pulp, and the pulp then enters a magnetic separator. The magnetic separator selects a slurry containing iron powder, and this slurry is pumped into a first cyclone. Part of the slurry selected by the first cyclone is filtered to obtain iron powder, and the other part is returned to a second cyclone. The diameter of the second cyclone is smaller than that of the first cyclone, and the slurry selected by the second cyclone is returned to the first cyclone to further sort iron powder; Sort lead chloride, copper hydroxide, gold, and silver. Through the above technical solution, the technical problem in the sorting process of dust removal ash in the related art that both the yield of extracts and the types of recovered substances are not high is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and specifically, to a separation process for sintering machine head ash in a steel plant. Background Art

[0002] A large amount of dust and sludge is generated in each process of the steel smelting process. Since the dust and sludge have certain recycling value, steel enterprises generally use it as secondary raw materials and return it to sintering for utilization. With the recycling of these solid wastes in sintering, harmful elements are continuously enriched, which has a significant impact on the quality of sinter.

[0003] The resource treatment of sintering flue gas dust can alleviate this problem and create considerable benefits. However, in the current separation process for dust, both the output of the extract and the types of recycled materials are not high. Summary of the Invention

[0004] The present invention provides a separation process for sintering machine head ash in a steel plant, which solves the technical problem that in the related art, both the output of the extract and the types of recycled materials in the separation process for dust are not high.

[0005] The technical solution of the present invention is as follows:

[0006] A separation process for sintering machine head ash in a steel plant includes the following process steps:

[0007] A. Raw material crushing: The material is put into a silo and enters a crushing device through a feeder for crushing;

[0008] B. Primary separation of iron powder: The crushed material in step A is fed into a flotation machine to select slurry, and the slurry then enters a magnetic separator. The magnetic separator selects the slurry containing iron powder, and this slurry is pumped into a first hydrocyclone. Part of the slurry selected by the first hydrocyclone is filtered to obtain iron powder, and the other part is returned to a second hydrocyclone. The diameter of the second hydrocyclone is smaller than that of the first hydrocyclone, and the slurry selected by the second hydrocyclone is returned to the first hydrocyclone for further separation of iron powder;

[0009] C. Secondary separation of iron powder: The tailings formed by the magnetic separator in step B are pumped into a third hydrocyclone. The underflow of the third hydrocyclone flows into a high-frequency screen, and the part on the screen is pumped into a fifth hydrocyclone and then into a spiral chute. The spiral chute selects the slurry containing iron powder and enters the first hydrocyclone in step B for further separation of iron powder;

[0010] D. Tertiary separation of iron powder: The part under the screen of the high-frequency screen in step C is pumped into a sixth hydrocyclone. The sand deposited by the sixth hydrocyclone enters a gravity separator, and the slurry containing iron powder selected by the gravity separator is pumped into the first hydrocyclone in step B for further separation of iron powder;

[0011] E. Sorting lead chloride: The overflow generated by the third cyclone in step C is pumped into the fourth cyclone. The overflow generated by the fourth cyclone flows into the thickener after the foam is separated by the foam separation tank. A part of the slurry generated by the thickener is pumped into the high-temperature reactor. Hydrochloric acid and steam are introduced into the high-temperature reactor, and then the filtrate is obtained through filtration. The precipitate obtained after the filtrate is cooled by the cooling tank is lead chloride;

[0012] F. Sorting copper hydroxide: The remaining slurry in the cooling tank in step E contains copper chloride. Sodium hydroxide is added to the slurry containing copper chloride, and then copper hydroxide is obtained after filtration by the filter press;

[0013] G. Sorting gold and silver: The remaining material after filtration in step E is sent to the leaching tank. A gold extraction agent is added to the leaching tank. The obtained slurry enters the adsorption tank and is analyzed and electrolyzed. Gold is obtained in the filtrate after passing through the intermediate frequency furnace, and the remaining is silver. The remaining material after the adsorption tank and the analysis and electrolysis is returned to the leaching tank to further extract gold and silver;

[0014] H. Sorting filter cake: The precipitate in the leaching tank in step G is pumped into the filter press to obtain the filter cake.

[0015] As a further technical solution, the following process is also included:

[0016] I. Sorting sodium chloride, potassium chloride and rubidium chloride: The overflow of the thickener in step E is filtered and evaporated, and then sodium chloride is obtained through the high-temperature reactor and the centrifuge. Potassium chloride is obtained after passing through the low-temperature reactor and the centrifuge. Then rubidium chloride is obtained after adding the ion exchange agent. The generated mother liquor is evaporated again;

[0017] J. Sorting miscellaneous salts: After the overflow of the thickener in step I is filtered, a part forms miscellaneous salts, and the solution part is evaporated.

[0018] As a further technical solution, the distilled water generated in steps F, H and I is collected and supplied to the equipment that requires fresh water.

[0019] As a further technical solution, the following process is also included:

[0020] Circular sorting in step A: The overflow generated by the fifth cyclone in step C, the tailings generated by the spiral chute, and the foam separated by the foam separation tank in step E are all returned to step A for re-crushing;

[0021] Circular sorting in step C: The sand deposited by the fourth cyclone in step E, the overflow generated by the sixth cyclone in step D, the medium tailings selected by the gravity separator in step D, the filtrate obtained by filtering the slurry selected by the first cyclone in step B, and the middlings generated by the spiral chute in step C are all returned to the third cyclone in step C for re-sorting;

[0022] Circulating separation in step D: The overflow generated by the second cyclone in step B and the middlings generated by the gravity separator in step D are returned to the sixth cyclone in step D for re-separation.

[0023] As a further technical solution, a hydraulic crushing box is used as the crushing equipment in step A.

[0024] As a further technical solution, the ion exchanger in step I is zeolite.

[0025] The working principle and beneficial effects of the present invention are as follows:

[0026] 1. The present invention uses a hydraulic crushing box to replace the ball mill, which is energy-saving and highly efficient. The particle size of the dust removal ash itself is low. In order to prevent dust from flying, water is sprayed. Since the dust removal ash contains calcium, particles and lumps are formed after spraying water. The original ball mill is used to grind large-volume particles, and it consumes high energy and has low efficiency when grinding dust removal ash. The present invention solves this technical problem well through the hydraulic crushing box;

[0027] 2. The present invention adds a foam separation box to recover the recoverable substances remaining in the foam.

[0028] 3. The present invention uses a high-frequency screen to separate the oversize and the undersize. The oversize is separated by a spiral chute, mainly separating iron, and the separation effect is better. It is found in actual work that the cyclone has a better separation effect on particles with a mesh size of 60 - 300, while the spiral chute has a better separation effect on particles between 20 - 60 mesh. Based on this discovery, the underflow of the first cyclone flows into the high-frequency screen, and the oversize and the undersize are separated by the high-frequency screen, thereby achieving more precise separation, making the separation effect of each element in the dust removal ash better and the purity higher.

[0029] 4. The process of the present invention can recover rubidium chloride in the final recovered product. Compared with other separation processes in the prior art, there is one more product. And according to the specific recovery conditions of sodium chloride, potassium chloride, and rubidium chloride, a specific recovery sequence is set. Evaporation is high-temperature evaporation, so sodium chloride is recovered first. And after sodium chloride, potassium chloride, and rubidium chloride are recovered, these elements are also less in the filter cake, and the filter cake can be further used by the cement plant.

[0030] 5. The present invention can also recover substances such as gold and silver through a reasonable process sequence. Description of the Drawings

[0031] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0032] Figure 1 It is a schematic process flow diagram of the present invention; Specific Embodiments

[0033] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a 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 those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0034] Embodiment 1

[0035] As Figure 1 shown, this embodiment proposes a sintering machine head ash separation process for a steel plant, including the following process steps:

[0036] A. Raw material crushing: The materials are put into the silo and enter the crushing equipment through the feeder for crushing;

[0037] B. Primary separation of iron powder: The materials crushed in step A are fed into a flotation machine to select pulp, and the pulp then enters a magnetic separator. The magnetic separator selects the slurry containing iron powder, and this slurry is pumped into a first hydrocyclone. Part of the slurry selected by the first hydrocyclone is filtered to obtain iron powder, and the other part returns to the second hydrocyclone. The diameter of the second hydrocyclone is smaller than that of the first hydrocyclone, and the slurry selected by the second hydrocyclone returns to the first hydrocyclone to further separate iron powder;

[0038] C. Secondary separation of iron powder: The tailings formed by the magnetic separator in step B are pumped into a third hydrocyclone. The underflow of the third hydrocyclone flows into a high-frequency screen, and the part on the screen is pumped into a fifth hydrocyclone and then into a spiral chute. The spiral chute selects the slurry containing iron powder and enters the first hydrocyclone in step B to further separate iron powder;

[0039] D. Tertiary separation of iron powder: The part under the screen of the high-frequency screen in step C is pumped into a sixth hydrocyclone. The sand deposited by the sixth hydrocyclone enters a gravity separator, and the slurry containing iron powder selected by the gravity separator is pumped into the first hydrocyclone in step B to further separate iron powder;

[0040] E. Separation of lead chloride: The overflow generated by the third hydrocyclone in step C is pumped into a fourth hydrocyclone. The overflow generated after the overflow from the fourth hydrocyclone is separated by a foam separation box flows into a thickener. Part of the slurry generated by the thickener is pumped into a high-temperature reactor, hydrochloric acid and steam are introduced into the high-temperature reactor, and then filtered to obtain a filtrate. The precipitate obtained after the filtrate is cooled by a cooling tank is lead chloride;

[0041] F. Separation of copper hydroxide: The remaining slurry in the cooling tank in step E contains copper chloride. Sodium hydroxide is added to the slurry containing copper chloride, and then it is filtered by a filter press to obtain copper hydroxide;

[0042] G. Sorting gold and silver: The remaining materials after filtration in step E are sent into the leaching tank. A gold extraction agent is added to the leaching tank. The resulting slurry enters the adsorption tank and is desorbed and electrolyzed. Gold is obtained from the filtrate after passing through the intermediate frequency furnace, and the remainder is silver. The remaining materials after the adsorption tank and desorption electrolysis are returned to the leaching tank for further extraction of gold and silver;

[0043] H. Sorting filter cake: The precipitate in the leaching tank in step G is pumped into a filter press to obtain the filter cake.

[0044] As a further technical solution, the following technological processes are also included:

[0045] I. Sorting sodium chloride, potassium chloride and rubidium chloride: The overflow from the thickener in step E is filtered and evaporated, then passes through a high-temperature reactor and a centrifuge to obtain sodium chloride, then passes through a low-temperature reactor and a centrifuge to obtain potassium chloride, and rubidium chloride is obtained after adding an ion exchange agent. The resulting mother liquor is evaporated again;

[0046] J. Sorting miscellaneous salts: After the overflow from the thickener in step I is filtered, a part forms miscellaneous salts, and the solution part is evaporated.

[0047] As a further technical solution, the distilled water generated in steps F, H and I is collected and supplied to the equipment that requires fresh water.

[0048] As a further technical solution, the following technological processes are also included:

[0049] Circular sorting in step A: The overflow generated by the fifth cyclone in step C, the tailings generated by the spiral chute, and the foam separated by the foam separation box in step E are all returned to step A for re-crushing;

[0050] Circular sorting in step C: The sand deposited by the fourth cyclone in step E, the overflow generated by the sixth cyclone in step D, the medium tailings selected by the heavy separator in step D, the filtrate obtained by filtering the slurry selected by the first cyclone in step B, and the middlings generated by the spiral chute in step C are all returned to the third cyclone in step C for re-sorting;

[0051] Circular sorting in step D: The overflow generated by the second cyclone in step B and the middlings generated by the heavy separator in step D are returned to the sixth cyclone in step D for re-sorting.

[0052] As a further technical solution, a hydraulic crushing box is used as the crushing equipment in step A.

[0053] As a further technical solution, the ion exchange agent in step I is zeolite.

[0054] The technological process of this embodiment has the following advantages:

[0055] 1. In this embodiment, a hydraulic crushing box is used to replace the ball mill, which is energy-saving and highly efficient. The particle size of the dust removal ash itself is low. In order to prevent dust from flying, water is sprayed. Since the dust removal ash contains calcium, particles and lumps are formed after spraying water. The original ball mill is used to grind large-volume particles, and it consumes high energy and has low efficiency when grinding dust removal ash. This embodiment solves this technical problem well through the hydraulic crushing box;

[0056] 2. In this embodiment, a foam separation box is added to recover the recoverable substances remaining in the foam.

[0057] 3. In this embodiment, a high-frequency screen is used to separate the oversize and the undersize. The oversize is separated by a spiral chute, mainly separating iron, and the separation effect is better. It is found in actual work that the hydrocyclone has a better separation effect on particles with a mesh size of 60 - 300, while the spiral chute has a better separation effect on particles between 20 - 60 meshes. Based on this discovery, the underflow of the first hydrocyclone flows into the high-frequency screen, and the oversize and the undersize are separated by the high-frequency screen, thereby achieving more accurate sorting, making the separation effect of each element in the dust removal ash better and the purity higher.

[0058] 4. The process of this embodiment can recover rubidium chloride in the final recovered substances. Compared with other sorting processes of the prior art, there is one more product. And according to the specific recovery conditions of sodium chloride, potassium chloride, and rubidium chloride, a specific recovery sequence is set. Evaporation is high-temperature evaporation, so sodium chloride is recovered first. Moreover, after sodium chloride, potassium chloride, and rubidium chloride are recovered, these elements are also less in the filter cake, and the filter cake can be further used by the cement plant.

[0059] 5. This embodiment can also recover substances such as gold and silver through a reasonable process sequence.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. The sintering machine head ash separation process of the steel plant is characterized in that, It includes the following technological processes: A. Raw material crushing: The materials are put into the storage bin and enter the crushing equipment through the feeder for crushing; B. First-stage separation of iron powder: The materials crushed in step A are fed into a flotation machine to produce pulp, and the pulp then enters a magnetic separator. The magnetic separator selects the slurry containing iron powder, and this slurry is pumped into the first hydrocyclone. A part of the underflow selected by the first hydrocyclone is filtered to obtain iron powder, and the other part of the underflow is pumped into the second hydrocyclone; The diameter of the second hydrocyclone is smaller than that of the first hydrocyclone, and the underflow selected by the second hydrocyclone is returned to the first hydrocyclone to further separate iron powder; C. Second-stage separation of iron powder: The tailings formed by the magnetic separator in step B are pumped into the third hydrocyclone. The underflow of the third hydrocyclone flows into a high-frequency screen, and the part on the screen is pumped into the fifth hydrocyclone. The underflow of the fifth hydrocyclone then enters a spiral chute. The spiral chute selects the slurry with iron powder and enters the first hydrocyclone in step B to further separate iron powder; D. Third-stage separation of iron powder: The part under the high-frequency screen in step C is pumped into the sixth hydrocyclone. The sand deposited by the sixth hydrocyclone enters a gravity separator, and the slurry containing iron powder selected by the gravity separator is pumped into the first hydrocyclone in step B to further separate iron powder; E. Separation of lead chloride: The overflow generated by the third hydrocyclone in step C is pumped into the fourth hydrocyclone. The overflow generated after the overflow of the fourth hydrocyclone is separated from the foam through a foam separation box flows into a thickener. The underflow generated by the thickener is pumped into a high-temperature reactor, hydrochloric acid and steam are introduced into the high-temperature reactor, and then it is filtered to obtain a filtrate. The precipitate obtained after the filtrate is cooled in a cooling tank is lead chloride; F. Separation of copper hydroxide: The remaining slurry in the cooling tank in step E contains copper chloride. Sodium hydroxide is added to the slurry containing copper chloride, and then it is filtered by a filter press to obtain copper hydroxide; G. Separation of gold and silver: The remaining materials after filtration in step E are sent to a leaching tank, a gold extraction agent is added to the leaching tank, and the resulting slurry enters an adsorption tank and is desorbed and electrolyzed. Gold is obtained in the filtrate after passing through an intermediate frequency furnace, and the remaining is silver. The remaining materials after the adsorption tank and desorption and electrolysis are returned to the leaching tank to further extract gold and silver; H. Separation of filter cake: The precipitate in the leaching tank in step G is pumped into a filter press to obtain a filter cake.

2. The sintering machine head ash separation process of the steel plant according to claim 1, characterized in that It also includes the following technological processes: I. Separation of sodium chloride, potassium chloride and rubidium chloride: The overflow of the thickener in step E is filtered and evaporated. The resulting precipitate is then processed through a high-temperature reactor and a centrifuge to obtain sodium chloride. The mother liquor obtained after the treatment of the high-temperature reactor and the centrifuge is further processed through a low-temperature reactor and a centrifuge to obtain potassium chloride. The mother liquor obtained after the treatment of the low-temperature reactor and the centrifuge is added with an ion exchanger to obtain rubidium chloride, and the resulting mother liquor is evaporated again; J. Separation of miscellaneous salts: After the overflow of the thickener in step I is filtered, the filter residue forms miscellaneous salts, and the solution part is evaporated.

3. The iron and steel plant sintering machine head ash separation process according to claim 2, characterized in that, The distilled water generated in steps F, H and I is collected and supplied to the equipment that requires fresh water.

4. The iron and steel plant sintering machine head ash separation process according to claim 3, characterized in that, It also includes the following technological processes: Circulating separation in step A: The overflow generated by the fifth hydrocyclone in step C, the tailings generated by the spiral chute, and the foam separated by the foam separation box in step E are all returned to step A for re-crushing; Circulating separation in step C: The sand deposits generated by the fourth hydrocyclone in step E, the overflow generated by the sixth hydrocyclone in step D, the medium and tailings selected by the gravity separator in step D, the filtrate obtained by filtering the slurry selected by the first hydrocyclone in step B, and the middlings generated by the spiral chute in step C are all returned to the third hydrocyclone in step C for re-separation; Circulating separation in step D: The overflow generated by the second hydrocyclone in step B and the middlings generated by the gravity separator in step D are returned to the sixth hydrocyclone in step D for re-separation.

5. The iron and steel plant sintering machine head ash separation process according to claim 4, characterized in that, In step A, a hydraulic crushing box is used as the crushing equipment.

6. The iron and steel plant sintering machine head ash sorting process according to claim 2, characterized in that, The ion exchanger in step I is zeolite.

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