CN113631739B - Recovery of chromite fines - Google Patents
Recovery of chromite fines Download PDFInfo
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- CN113631739B CN113631739B CN202080023373.4A CN202080023373A CN113631739B CN 113631739 B CN113631739 B CN 113631739B CN 202080023373 A CN202080023373 A CN 202080023373A CN 113631739 B CN113631739 B CN 113631739B
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- 238000011084 recovery Methods 0.000 title description 13
- 239000002002 slurry Substances 0.000 claims abstract description 103
- 238000000034 method Methods 0.000 claims abstract description 94
- 239000000696 magnetic material Substances 0.000 claims abstract description 53
- 239000012141 concentrate Substances 0.000 claims abstract description 46
- 238000007885 magnetic separation Methods 0.000 claims abstract description 22
- 239000002699 waste material Substances 0.000 claims abstract description 10
- 239000000463 material Substances 0.000 claims description 71
- 239000006148 magnetic separator Substances 0.000 claims description 38
- 238000000926 separation method Methods 0.000 claims description 33
- 239000006246 high-intensity magnetic separator Substances 0.000 claims description 12
- 238000004140 cleaning Methods 0.000 claims description 5
- 238000011144 upstream manufacturing Methods 0.000 claims description 4
- 206010001497 Agitation Diseases 0.000 claims 1
- 238000013019 agitation Methods 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 40
- 239000002562 thickening agent Substances 0.000 description 26
- 239000011651 chromium Substances 0.000 description 12
- 230000005484 gravity Effects 0.000 description 11
- JTJMJGYZQZDUJJ-UHFFFAOYSA-N phencyclidine Chemical class C1CCCCN1C1(C=2C=CC=CC=2)CCCCC1 JTJMJGYZQZDUJJ-UHFFFAOYSA-N 0.000 description 7
- 238000002360 preparation method Methods 0.000 description 7
- 239000000701 coagulant Substances 0.000 description 5
- 230000004907 flux Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 description 4
- 239000011707 mineral Substances 0.000 description 4
- 238000005086 pumping Methods 0.000 description 4
- 238000011010 flushing procedure Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 238000012512 characterization method Methods 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 210000004907 gland Anatomy 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000003621 irrigation water Substances 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 239000002516 radical scavenger Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000010977 unit operation Methods 0.000 description 2
- 229910000604 Ferrochrome Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- -1 e.g. Substances 0.000 description 1
- 229910001710 laterite Inorganic materials 0.000 description 1
- 239000011504 laterite Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C1/00—Magnetic separation
- B03C1/02—Magnetic separation acting directly on the substance being separated
- B03C1/30—Combinations with other devices, not otherwise provided for
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B7/00—Combinations of wet processes or apparatus with other processes or apparatus, e.g. for dressing ores or garbage
Landscapes
- Manufacture And Refinement Of Metals (AREA)
- Separation Of Solids By Using Liquids Or Pneumatic Power (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Catalysts (AREA)
- Treatment Of Sludge (AREA)
Abstract
A method (10, 200) for recovering chromite fines from a slurry, the method comprising: feeding a feed slurry (68) comprising chromite fines to a wet-spiral beneficiation stage (14) comprising a plurality of wet-spiral separators or wet-spiral beneficiators (32); separating the slurry (68) into a high grade chromite slurry (74), a low grade chromite slurry (76) and a first tailings stream (78) by a wet spiral separator or wet spiral concentrator (32); magnetic separating the low-grade chromite slurry (76) into a magnetic material stream (80) and a non-magnetic material waste stream (86) in a wet magnetic separation stage (24); and separating the high grade chromite slurry (74) and the magnetic material stream (80) into a chromite concentrate (90) and a second tailings stream (92) in a shaker stage (18).
Description
The invention relates to the recovery of chromite fines. In particular, the invention relates to a process for recovering chromite fines from a slurry.
Treatment of chromite ore (FeCr) 2 O 4 ) Tailings or tailings are typically produced from the plant, typically in the form of a slurry or slurry stream containing valuable chromite fines. Recovery of chromite fines from such slurry or slurry streams in a cost effective manner is difficult, especially for-75 μm chromite fines. The loss of chromite from the tailings from the chromite processing plant may be significant, with the loss of Cr in the chromite fed to the chromite processing plant being about 35 to 40 mass%.
Thus, there is a need for a process for economically and efficiently recovering chromite fines from a slurry.
According to the present invention there is provided a process for recovering chromite fines from a slurry, said process comprising the steps of:
feeding a feed slurry (feed slurry) comprising chromite fines to a wet spiral beneficiation stage comprising a plurality of wet spiral separators or wet spiral beneficiators;
separating the slurry into a high-grade chromite slurry, a low-grade chromite slurry and a first tailings stream by a wet spiral separator or a wet spiral concentrator;
magnetic separation of the low-grade chromite slurry into a magnetic material stream and a non-magnetic material waste stream in a wet magnetic separation (wet magnetic separation) stage; and
the high grade chromite slurry and the magnetic material stream are separated into a chromite concentrate and a second tailings stream in a shaker stage.
Tripath, sunil Kumar, ramamurthy, y. And Singh, veerendra, "Recovery of chromite values from plant tailings by gravity concentration" (recovery of chromite values from mill tailings by gravity beneficiation) ("journal of mineral and material characterization and engineering (Journal of Minerals and Material Characterization and Engineering), volume 10, stage 1, pages 13-25, month 2011) discloses beneficiation of chromite streams with a spiral concentrator (concentrator) and shaker (shaking table) in which at least 50% of fines are 100 μm to 35 μm. Tripathy, sunil Kumar and Murthy, Y.Rama, "Multiobjective optimisation of spiral concentrator for separation of ultrafine chromite" (multi-objective optimization of a spiral concentrator for separating ultrafine chromite) ("J. International mining and mineral engineering (International Journal of Mining and Mineral Engineering), volume 4, phase 2, month 1 2012) also mentions spiral separation of ultrafine chromite (spiral separation), wherein 70% of the chromite particles have a particle size of less than 75 μm. US 3323900, CN 101823018 and CN 201366374 mention the recovery of chromium from laterite (lastite) using a spiral separator. US 3323900, US 3935094, RU 2208060, CN 101823018, CN 201366374, ZA 2011/00444 and ZA 2014/004437 disclose magnetic separation of chromite-containing fines. ZA 2005/03034 teaches mechanical cleaning of the chromite crystal surfaces present in chromite fines and magnetic separation of iron oxide. US 3,323,900, CN 101823018 and CN 201366374 disclose shaking tables for chromite recovery. However, none of these documents teaches or suggests a process according to the present invention, the use of the same sequence of unit operations as in the process of the present invention, and the use of the same feed and product streams connecting the various unit operations.
The method may include subjecting the feed slurry to a feed preparation stage prior to feeding the feed slurry to the wet spiral beneficiation stage.
In the feed preparation stage, the feed slurry may be screened to separate oversized material from the feed slurry. Typically, oversized material is discharged onto a pile (dump).
The feed preparation stage may be configured to separate +1000 μm, preferably +950 μm, more preferably +900 μm, most preferably +850 μm of oversized material from the feed slurry.
During the feed preparation stage, magnetic material (e.g., entrained metals) may be magnetically separated from the feed stream in a plurality of wet medium intensity magnetic separators operating in parallel. Typically, the magnetic material is discharged onto the pile along with, for example, oversized material.
If necessary or desired, the method may include: water is added to the feed slurry from the screen (i.e., to the underflow from the screen) during the feed preparation stage to reduce the consistency of the feed slurry prior to magnetic separation of the magnetic material from the feed slurry.
Wet medium strength magnetic separators can produce a magnetic flux strength of about 0.2 tesla to about 0.8 tesla, preferably about 0.3 tesla to about 0.7 tesla, most preferably about 0.4 tesla to about 0.6 tesla, for example about 0.5 tesla.
The method may comprise: at least one of the high grade chromite slurry stream and the magnetic material stream is subjected to a size separation stage to produce one or more finer material fractions or underflow fractions and one or more coarser material fractions or overflow fractions, after which the at least one high grade chromite slurry stream and the magnetic material stream are separated in a shaker stage into chromite concentrate (concentrate) and a second tailings stream in the form of at least the one or more finer material fractions and optionally the one or more coarser material fractions. Preferably, both the high grade chromite slurry and the magnetic material are subjected to a size separation stage.
In one embodiment of the invention, as an alternative to separating one or more coarser material fractions from the size separation stage in the shaker stage, the one or more coarser material fractions from the size separation stage are discharged as tailings.
The size separation stage typically includes one or more screens to separate the high grade chromite slurry and the magnetic material stream into two size components, for example, a +100 μm component and a-100 μm component, or a +90 μm component and a-90 μm component.
Cr of feed slurry based on dry material 2 O 3 The content is about 7 mass% to about 11 mass%, for example about 9 mass%.
The feed slurry fed to the wet spiral beneficiation stage can comprise chromite fines such that at least 90% of the chromite fines pass through a 150 μm square mesh, or through a 125 μm square mesh, or through a 115 μm square mesh, or through a 100 μm square mesh.
More than 50% or more than 60% or more than 70% or more than 80% of the chromite fines in the feed slurry fed to the wet spiral beneficiation stage are typically-75 μm material.
The method may include: the feed slurry is dewatered prior to feeding the feed slurry to a wet spiral separator or wet spiral concentrator. Dewatering of the feed slurry may be accomplished using any suitable dewatering technique or equipment (e.g., dewatering cyclones). Typically, the water removed from the feed slurry is fed to a thickener (thickener) or the like.
The specific gravity of the feed slurry to the wet-spiral separator or wet-spiral concentrator relative to water may be from about 1.2 to about 1.8, preferably from about 1.3 to about 1.7, more preferably from about 1.4 to about 1.6, for example about 1.5.
The pitch angle (pitch) of the wet spiral separator or wet spiral concentrator may be from about 4 ° to about 10 °, preferably from about 4 ° to about 9 °, more preferably from about 5 ° to about 8 °, for example about 6.5 °.
The wet-process spiral separator or wet-process spiral concentrator may have a diameter of about 50cm to about 150cm, preferably about 60cm to about 140cm, more preferably about 70cm to about 130cm, for example about 90cm.
The inclination angle (profile) of the wet spiral separator or wet spiral concentrator may be from about 1 ° to about 5 °, preferably from about 1.5 ° to about 4.5 °, more preferably from about 2 ° to about 4 °, for example about 3 °.
The height of the wet-process spiral separator or wet-process spiral concentrator may be from about 2 turns (turn) to about 6 turns, preferably from about 3 turns to about 5 turns, for example about 4 turns.
Each wet spiral separator or wet spiral concentrator may provide the feed slurry at a rate of from about 0.5 to about 1.5 tons/hour, preferably from about 0.6 to about 1.4 tons/hour, more preferably from about 0.7 to about 1.3 tons/hour, for example about 1 ton/hour.
The wet screw separator or wet screw concentrator may be configured such that the higher grade chromite slurry is a concentrate fraction (cut) from the wet screw separator or wet screw concentrator, the lower grade chromite slurry is a middling (middings) fraction from the wet screw separator or wet screw concentrator, and the first tailings stream is a tailings fraction from the wet screw separator or wet screw concentrator.
Typically, all wet-process spiral separators or wet-process spiral separators are rougher (rougher) spiral separators or separators, and the process therefore does not employ clean or rinse (scavenger) spiral separators or separators.
The wet spiral separator or wet spiral concentrator may be constructed and operated as Cr of a high grade chromite slurry on a dry matter basis 2 O 3 The content is about 11 to about 20 mass%, preferably about 12 to about 19 mass%, more preferably about 13 to about 18 mass%, for example about 16 mass%.
The wet spiral separator or wet spiral concentrator may be constructed and operated as Cr of a low grade chromite slurry (i.e. middlings) on a dry matter basis 2 O 3 The content is about 6 to about 11 mass%, preferably about 7 to about 9 mass%, for example about 8 to 10 mass%.
The wet spiral separator or wet spiral concentrator may be constructed and operated to provide Cr in the first tailings stream on a dry matter basis 2 O 3 The content is less than about 8 mass%.
The wet spiral separator or wet spiral concentrator may be configured and operated with a mass flow ratio of high grade chromite slurry to low grade chromite slurry of from about 1:1.5 to about 1:2.5 on a dry matter basis, for example, about 1:2.
The magnetic separation of the low-grade chromite slurry in the wet magnetic separation stage may comprise passing the low-grade chromite slurry through a plurality of wet high intensity magnetic separators operating in parallel. The wet high intensity magnetic separators may be roughing separators (rougher separator) that each produce a magnetic flux density of about 1 tesla (tesla) to about 1.4 tesla, for example about 1.2 tesla.
The magnetic separation of the low-grade chromite slurry in the wet magnetic separation stage may comprise: the non-magnetic material reject stream is transported from the roughing separator to a further or downstream wet high intensity separator, i.e. a rinse separator (scavenger separator), which operates in parallel. The rinse separators may each produce a magnetic flux density of about 1 tesla to about 1.4 tesla, for example about 1.2 tesla.
If desired, magnetic separation of the low grade chromite slurry in a wet magnetic separation stage may comprise: the non-magnetic material waste stream is conveyed from the flush separator to at least one further downstream set of flush separators operating in parallel.
In one embodiment of the invention, the wet high intensity magnetic separators of the wet magnetic separation stage are grouped together into processing units, each processing unit comprising a roughing wet high intensity magnetic separator, followed by two downstream flushing wet high intensity magnetic separators in series. The magnetic material streams from the roughing and flushing wet high intensity magnetic separators are combined to form a magnetic material stream that is fed to the shaker stage, typically through a size separation stage.
The method may include: the one or more finer material components are dewatered prior to separation into chromite concentrate and a second tailings stream in a shaker stage. Dewatering of the one or more finer material components may be accomplished using any suitable dewatering technique or equipment (e.g., dewatering cyclones). Typically, the water removed from the finer material component or components is fed to a thickener or the like, possibly through a guard cyclone or the like.
Typically, if one or more of the coarser material fractions are separated in the shaker stage but not discharged, there is no need to dewater the one or more coarser material fractions before they are separated in the shaker stage.
The shaking phase may employ a plurality of shaking or wilforey-type shaking tables (Wilfley tables) for the one or more finer material components, and in one embodiment of the invention, a plurality of shaking or wilforey-type shaking tables for the one or more coarser material components. Thus, one or more of the finer material fractions may be treated separately from one or more of the coarser material fractions during the shaking phase. The number of shakers required for one or more of the finer material fractions may be greater than the number of shakers required for one or more of the coarser material fractions.
As an alternative to separating the one or more coarser material fractions from the size separation stage in the shaker stage, the one or more coarser material fractions from the size separation stage are discharged as tailings.
The shaker stage may include: and a rougher upstream of the cleaning shaker. Typically, in this embodiment of the invention, the one or more finer material components or underflow components from the size separation stage alone are thereby fed to the rougher bed and the one or more coarser material components from the size separation stage are discharged, for example as tailings, and are not processed in the bed stage.
The specific gravity of the finer material component or components fed to the shaker relative to the water may be from about 1.1 to about 1.6, preferably from about 1.2 to about 1.5, more preferably from about 1.3 to about 1.4, for example about 1.35.
In one embodiment of the invention, concentrate components from a shaker that processes one or more finer material components and a shaker that processes one or more coarser material components form or constitute chromite concentrate. Thus, the concentrate component consists of the most dense material from the shaker. Typically, chromite concentrate is dewatered (e.g. using dewatering cyclones) and stacked in a stockpile (stockpile). The water obtained after dewatering the chromite concentrate may be fed to a thickener, possibly by a guard cyclone or the like.
The middling component and the tailings component from each shaker may form a second tailings stream. The middling and tailing fractions from each shaker are fractions that are less dense than the fractions without the concentrate fraction.
The method may include: the first and second tailings streams from the wet magnetic separation stage and the non-magnetic material reject stream are combined into a tailings stream and the tailings stream is treated to recover water, for example, for use as production water. The tailings stream will also typically contain water from any dewatering operations performed. Treatment of the tailings stream typically involves the use of a thickener and may also include a sedimentation tank (clarifier). The outlet of the tailings stream may comprise, if desired or necessary: the tailings stream is first passed through a guard cyclone, the tailings stream is separated into an oversized material stream and an undersized material stream, and the oversized material stream is fed to a thickener, the undersized material stream being treated in a tailings storage facility.
In another embodiment of the invention, wherein the method comprises treating only one or more finer material fractions or underflow fractions from the size separation stage on a rougher and a cleaner shaker, the method comprises further processing stages for treating at least one middling fraction from the cleaner shaker, and the concentrate fraction from the cleaner shaker constitutes chromite concentrate.
Preferably, at other processing stages, the middling fraction from the rougher and the tailings fraction from the cleaner shaker will also be treated.
Other processing stages may include a roughing wet magnetic separator that receives material from the shaker stage.
Typically, the rougher wet magnetic separator of the other processing stages receives middling components from the rougher, middling components from the cleaner shaker, and tailings components from the cleaner shaker.
Other processing stages may include a clean wet magnetic separator that receives magnetic material from a roughing wet magnetic separator. The non-magnetic material from the roughing separator may be discharged, for example as tailings.
The method may include: in other processing stages, the magnetic material from the clean wet magnetic separator is dewatered and the dewatered magnetic material from the clean wet magnetic separator is recycled to the clean shaker. Dewatering of the magnetic material from the clean wet magnetic separator may be accomplished using any suitable dewatering technique or equipment (e.g., dewatering cyclones). In general, feeding water removed from the magnetic separation material of the clean wet magnetic separator to a thickener or the like may be performed by a guard cyclone or the like.
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 shows one embodiment of the process of the present invention for recovering chromite fines from a slurry; and is also provided with
Figure 2 shows another embodiment of the process of the invention for recovering chromite fines from a slurry.
Referring to fig. 1 of the drawings, the reference numeral 10 generally designates the process of the present invention for recovering chromite fines from a slurry. The method 10 generally includes: a feed preparation stage 12, a wet spiral beneficiation stage 14, a size separation stage 16, a shaker stage 18, a concentrate treatment stage 20, a tailings treatment stage 22 and a wet magnetic separation stage 24.
Feed preparation stage 12 is provided with a screen 26 and a plurality of (e.g., 10) wet medium intensity magnetic separators 28 operating in parallel.
The wet spiral beneficiation stage 14 is provided with a plurality of dewatering cyclones 30 and a plurality (e.g., one hundred sixty) of roughing wet spiral separators or wet spiral beneficiators 32.
Wet magnetic separation stage 24 includes: a first set of 14 parallel operated wet high intensity roughing magnetic separators 34, a second set of wet high intensity rinse magnetic separators 36 (also 14 parallel operated), and a third set of wet high intensity rinse magnetic separators 38 downstream of the second set of wet high intensity rinse magnetic separators 36. There are also 14 wet high strength rinse magnetic separators 38 in the third set of wet high strength rinse magnetic separators 38.
The size separation stage 16 includes a pair of screens 40, 42, but a single screen may be used. Generally, in the embodiment shown in FIG. 1, the screen 42 is actually a pair of screens, considering that the load of the screen 42 is higher than the load of the screen 40. In the embodiment shown in fig. 1, the screens 42, 42 are 100 μm screens. In another embodiment of the invention, the screen is a 90 μm screen.
The shaker stage 18 has a plurality of dewatering cyclones 44, a plurality (e.g., 42) -100 μm shakers 46, and a plurality (e.g., 24) +100 μm shakers 48.
The concentrate treatment stage 20 includes a dewatering cyclone (not shown) and a chromite stacker 50.
The tailings treatment stage 22 includes a thickener 52 and a sedimentation tank 54.
The method 10 is configured to process about 420 tons/smallA feed slurry of chromite fines (i.e. tailings) produced from a chromite recovery plant (not shown) processing chromite ore raw ore. Cr of feed slurry on dry matter basis 2 O 3 The content is generally about 8 to 10 mass%. The chromite fines in the feed slurry were such that at least 90% of the chromite fines passed through a square mesh of 115 μm.
The feed slurry is fed to the screen 26 through a feed slurry line 60, wherein +850 μm oversized waste material is removed through an overflow line 62. The underflow from screen 26 is fed to wet medium intensity magnetic separator 28 via underflow line 64. Magnetic waste material (e.g., iron) is removed by wet medium intensity magnetic separator 28 and combined with oversized material from screen 26 by magnetic material line 66.
Wet medium intensity magnetic separators 28 each produce a magnetic flux strength of about 0.5 tesla or about 0.6 tesla that is high enough to remove magnetic waste material (e.g., iron) but low enough to produce a non-magnetic material slurry stream comprising chromite fines, which is then removed via slurry line 68 and pumped to dewatering cyclone 30 of wet spiral beneficiation stage 14.
The dewatering cyclone 30 removes some of the water from the slurry, producing a slurry with a specific gravity of about 1.5 relative to water. The water removed from the slurry by the dewatering cyclone 30 is withdrawn through overflow line 70 and pumped to thickener 52.
Dense slurry is removed from dewatering cyclone 30 via underflow line 72 and fed to wet spiral separator or wet spiral concentrator 32. Each wet spiral separator or wet spiral concentrator 32 is provided with a slurry having a specific gravity of 1.5 of about 1 ton/hour. The roughing wet-process spiral separator or wet-process spiral concentrator 32 each had a diameter of about 90cm, a pitch angle of about 5 °, an inclination angle of about 1-5 °, and a height of about 4 turns. Three fractions were removed from each roughing wet-process spiral separator or wet-process spiral concentrator 32. The first fraction is a radially inner fraction (radially inner cut), i.e. a high grade chromite slurry, which is removed by means of concentrate line 74. The low grade slurry is a radially intermediate middling fraction that is removed via middling line 76. The radially outer tailings fraction is removed as a first tailings stream and pumped through a first tailings stream line 78 to the thickener 52. There is no rinse spiral separator or wet spiral concentrator in the spiral beneficiation stage 14.
Although not shown in the drawings, process water is typically added to the high grade chromite slurry and the low grade chromite slurry to reduce the slurry consistency before the slurry is pumped to the size separation stage 16 and wet magnetic separation stage 24, respectively.
Cr of middling fraction on dry matter basis 2 O 3 The content is about 8 to 10 mass% and accounts for about 40 to 50 mass% of the slurry fed to the roughing wet-process spiral separator or wet-process spiral concentrator 32. The middling fraction is pumped through middling line 76 to wet magnetic separation stage 24 for distribution to the first set of wet high intensity magnetic separators 34 for further processing to recover residual chromite. Wet high intensity magnetic separator 34 is used as a roughing separator, each producing a magnetic flux density of about 1.2 tesla. Wet high intensity magnetic separator 34 produces a magnetic material stream that is removed through magnetic material stream line 80. Non-magnetic scrap material from wet high intensity magnetic separator 34 is gravity fed to a second set of downstream wet high intensity rinse magnetic separators 36 via non-magnetic material feed line 82 from which magnetic material is again withdrawn via magnetic material flow line 80 and from which non-magnetic scrap material is withdrawn via non-magnetic material feed line 84. The non-magnetic material feed line 84 gravity feeds non-magnetic reject material to the third set of downstream wet high intensity rinse magnetic separators 38, again producing a magnetic material stream withdrawn through the magnetic material stream line 80 and a non-magnetic reject stream withdrawn through the non-magnetic reject material withdrawal line 86 (leading to the thickener 52).
The magnetic material in the magnetic material flow line 80 is pumped to the size separation stage 16 and discharged onto the screen 42 (typically two screens in practice). If necessary, magnetic material (not shown) is added to the process water so that the volumetric flow rate remains constant. Similarly, concentrate from concentrate line 74 is fed to the size separation stage 16 and discharged onto the screen 40. Screens 40, 42 separate the material discharged onto the screens into +100 μm components and-100 μm components. The oversized material is washed by spraying process water onto the oversized material. The-100 μm fraction from screens 40, 42 is pumped through slurry line 75 to dewatering cyclone 44 of shaker stage 18, while the +100 μm fraction from screens 40, 42 is fed directly through slurry line 77 to +100 μm shaker 48 of shaker stage 18.
In shaker stage 18, the-100 μm component is first dewatered in dewatering cyclone 44 and water is removed via overflow line 88 and fed to thickener 52. The underflow of the dewatering cyclone 44 has a specific gravity of about 1.35 relative to water and is fed to the-100 μm shaker 46 via flow line 79. The 100 μm and +100 μm shakers are universal wilfory shakers for separating particles based on density and size, each producing a concentrate component, a middling component and a tailings component. The concentrate fraction from the-100 μm table 46 and the concentrate fraction from the +100 μm table 48 are withdrawn through concentrate line 90 and fed to the concentrate treatment stage 20. The middling and tailings components from-100 μm shaker 46 and +100 μm shaker 48 are combined to form a second tailings stream that is fed to thickener 52 via second tailings stream line 92.
In the concentrate treatment stage 20, concentrate from the concentrate line 90 is used with a dewatering cyclone (not shown) and the dewatered concentrate is stacked onto a concentrate heap 94 by means of a chromite stacker 50. On a dry matter basis, cr of concentrate stack 94 2 O 3 The content is generally about 40 mass%.
The thickener 52 of the tailings treatment stage 22 receives a first wake from the first wake line 78, non-magnetic waste material from the non-magnetic material withdrawal line 86, a second wake from the second wake line 92, an underflow from the underflow line 104 (which leads from the sedimentation tank 54 to the thickener 52), water from the dewatering cyclone 30 discharged through the overflow line 70, water from the dewatering cyclone 44 discharged through the overflow line 88, and water from the dewatering cyclone (not shown) of the concentrate treatment stage 20. Thickener 52 is provided with coagulant via coagulant feed line 96. The underflow 106 from the thickener 52 contains about 3 to 4 mass% on a dry matter basisCr of (2) 2 O 3 It is discharged and pumped to a tailings storage facility. Overflow from thickener 52 is fed to settling tank 54 through overflow line 98 and is also provided with flocculant (flocculant) from flocculant feed line 96 and coagulant (coagulant) from coagulant feed line 100. The underflow from the settling tank 154 is returned to the thickener via underflow flow line 104 and the overflow from the settling tank 54 is withdrawn via process water line 102 and fed to a process water tank (not shown) for use in the process 10 as process water, e.g., spray water, wash water, gland seal water, dilution water, and rinse and irrigation water (water for flushing and hosing).
Fig. 2 shows another embodiment of the process of the present invention for recovering chromite fines from a slurry, indicated generally by the reference numeral 200. Fig. 2 is simplified from fig. 1, omitting many of the detailed features of the various processing stages, but rather serves to emphasize the differences between the methods 10 and 200 at an overview level. However, unless otherwise indicated, the same reference numerals used in method 10 of fig. 1 are used in method 200 of fig. 2 to indicate the same or similar method features.
Unlike the method 10 in which oversized material from the screens 40, 42 of the oversized separation stage 16 is treated in the shaker stage 18, oversized material from the oversized separation stage 16 of the method 200 is discharged as tailings through the oversized material withdrawal line 202. In other words, in the method 200, the oversized material from the screen of the size separation stage 16 is not further processed to recover chromite. The size separation stage 16 of the process 200 is used to remove oversized materials that negatively impact the chromite recovery efficiency of the shaker stage 18.
Thus, another difference between method 200 and method 10 is that: in shaker stage 18, as an alternative to the parallel processing of oversized material and oversized material from size separation stage 16 on separate shakers 46, 48 in method 10, shaker stage 18 of method 200 has a plurality of rougher shakers 246 upstream of a plurality of cleaner shakers 248. Only oversized material from the size separation stage 16 is fed through the slurry line 75 to the shaker stage 18, dewatered in the dewatering cyclone 44, and then processed on the rougher shaker 246. The roughing cradle 246 serves to maximize the recovery of chromite from the wet spiral beneficiation stage 14 and the wet spiral beneficiation stage 24. The density of the slurry fed to rougher bed 246 is controlled using dewatering cyclone 44.
Roughing shaker 246 is a three-layer shaker (triple-deck shaking table) that receives the underflow from dewatering cyclone 44 and adds wash water to shaker 246 to improve feed material separation. The roughing cradle 246 serves to maximize the recovery of chromite from the high quality chromite slurry obtained from the wet spiral beneficiation stage 14 and the magnetic material obtained from the wet spiral beneficiation stage 24. Three products, namely concentrate, middlings and tailings, are recovered from rougher 246. Concentrate is fed through flow line 204 to clean shaker 248 for further processing. Middlings from rougher 246 are fed via flow line 206 to other processing stages, as will be described in more detail below. Tailings from rougher 246 are drawn through second tailings stream line 92.
Clean shaker 248 is used to upgrade the rougher concentrate to the chromite grade specification required for the final concentrate product. There are 16 three-layer cleaning shakers 248. The clean shaker 248 receives wash water to summarize feed material separation. Three products, namely concentrate, middlings and tailings, were recovered from the clean shaker 248. Middlings and tailings are fed to other processing stages via flow lines 208 and 210. Concentrate from the clean bench 248 is withdrawn through concentrate line 90 and dewatered using a stacker cyclone (not shown), and then the underflow from the stacker cyclone is stacked onto a concentrate heap 94 by chromite stacker 50. On a dry matter basis, cr of concentrate stack 94 2 O 3 The content is generally about 40 mass%.
Other processing stages that do not form part of the process 10 include a roughing wet magnetic separator 212 upstream of the clean wet magnetic separator 214, and a dewatering cyclone 216.
Middlings from roughing shaker 246 of shaker stage 18 are fed to roughing wet separator 212 via flow line 206. Rougher wet separator 212 also receives middlings and tailings from clean shaker 248 of shaker stage 18 via flow lines 208 and 210. Roughing wet magnetic separator 212 produces a non-magnetic material reject stream (which is withdrawn via second tailings stream line 92) and a magnetic material stream (which is conveyed from roughing wet magnetic separator 212 to downstream clean wet magnetic separator 214 via flow line 213).
Clean wet magnetic separator 214 also produces a non-magnetic material reject stream (which is withdrawn via second tailings stream line 92) and a magnetic material stream (which is conveyed via flow line 218 to dewatering cyclone 216).
Overflow from the dewatering cyclone 216 is withdrawn through the second tailings stream line 92. The underflow from the dewatering cyclone 216 is withdrawn via flow line 20 and recycled back to the clean shaker 248 of the shaker stage 18 for density control. Thus, the density of the slurry fed to the cleaning shaker 248 is controlled by the operation of the rougher shaker 246 and the operation of the dewatering cyclones 216 of the other processing stages 250.
Another difference between method 200 and method 10 is: the method 200 has a guard cyclone 260 forming part of the tailings treatment stage 22. In the method 200, the first tailings stream from the spiral separation stage 14 is fed to the guard cyclone 260 through the first tailings stream line 78, rather than directly to the thickener 52. Similarly, the second tailings stream line 92 and the non-magnetic waste material withdrawal line 86 are directed to the guard cyclone 260 and not directly to the thickener 52.
The tailings treatment stage 22 of the method 200 is shown with a tailings pumping system 270. The underflow from guard cyclone 260 flows under gravity through flow line 262 to tailings pumping system 270, while the overflow from guard cyclone 260 flows under gravity through flow line 264 to thickener 52. The underflow from thickener 52 is conveyed via flow line 266 to tailings pumping system 270. Flow line 268 leads from tailings pumping system 270 to a tailings storage facility (not shown).
Overflow from thickener 52 is drawn off through process water line 104 and fed to a process water tank (not shown) for use as process water in method 200, such as spray water, wash water, gland seal water, dilution water, and rinse and irrigation water. The main source of process water is thickener overflow, with raw water make-up (not shown) provided if necessary.
The method 200 is configured to process a feed slurry of about 500 tons/hour containing a chromite fines (i.e., tailings) composition produced by a chromite recovery plant (not shown) processing a chromite ore concentrate. Cr of feed slurry on dry matter basis 2 O 3 The content is generally about 8 to 10 mass%. The chromite fines in the feed slurry were such that at least 90% of the chromite fines passed through a square mesh of 115 μm.
The method 10, 200 as shown recovers chromite concentrate, cr of which is in an economically efficient manner on a dry matter basis 2 O 3 The content is at most about 40 mass%. Only a relatively small portion of Cr in the feed slurry 2 O 3 (e.g., about 4-5% on a dry matter basis) is discharged from thickener 52 as waste material. Thus, the methods 10, 200 as shown may advantageously recover a substantial portion of the chromium (as Cr 2 O 3 ) Even when the majority of chromite fines are-75 μm.
Claims (15)
1. A process for recovering chromite fines from a slurry, said process comprising:
feeding a feed slurry comprising chromite fines to a wet spiral beneficiation stage comprising a plurality of wet spiral separators or wet spiral beneficiators, such that at least 90% of the chromite fines pass through a square mesh of 150 μm, and Cr of the feed slurry 2 O 3 The content is 7 to 11 mass%;
separating the slurry into a high-grade chromite slurry, a low-grade chromite slurry and a first tailings stream by a wet spiral separator or a wet spiral concentrator to enable Cr of the high-grade chromite slurry to be separated into a high-grade chromite slurry and a low-grade chromite slurry 2 O 3 The content of Cr is 11 to 20 mass% based on dry basis, so that the low-grade chromite slurry contains Cr 2 O 3 The content is 6 to 11 mass% on a dry basis;
magnetic separating the low-grade chromite slurry into a magnetic material stream and a non-magnetic material waste stream in a wet magnetic separation stage comprising a plurality of magnetic separators; and
the high grade chromite slurry and the magnetic material stream are separated into a chromite concentrate and a second tailings stream in a shaking stage comprising a plurality of shaking tables.
2. A process according to claim 1, wherein the feed slurry fed to the wet spiral beneficiation stage comprises chromite fines such that at least 90% of the chromite fines pass through a 125 μm square mesh, or through a 115 μm square mesh, or through a 100 μm square mesh.
3. The method of claim 1, wherein magnetically separating the low-grade chromite slurry in the wet magnetic separation stage comprises: the low grade chromite slurry is passed through a plurality of wet high intensity roughing magnetic separators operating in parallel and the non-magnetic material reject stream is transported from the roughing magnetic separator to a wet high intensity magnetic separator operating further downstream in parallel, the wet high intensity magnetic separator being a flush separator.
4. The method of claim 1, the method comprising: at least one of the high grade chromite slurry stream and the magnetic material stream is subjected to a size separation stage to produce one or more finer material fractions or underflow fractions and one or more coarser material fractions or overflow fractions, and then the at least one high grade chromite slurry stream and the magnetic material stream are separated in a shaker stage into chromite concentrate and a second tailings stream in the form of at least the one or more finer material fractions and optionally the one or more coarser material fractions.
5. The method of claim 4, wherein the shaking stage employs a plurality of shaking tables for one or more finer material components and a plurality of shaking tables for one or more coarser material components, whereby the one or more finer material components are processed independently of the one or more coarser materials in the shaking stage.
6. The process of claim 4, wherein, as an alternative to separating the one or more coarser material fractions from the size separation stage in the shaker stage, the one or more coarser material fractions from the size separation stage are discharged as tailings.
7. The method of claim 6, wherein the agitation stage comprises a rougher upstream of the cleaning stage and the one or more finer material components from the size separation stage are fed to the rougher.
8. The method of claim 7, comprising a further processing stage for treating at least the middling fraction from the clean bench and the concentrate fraction from the clean bench constitutes chromite concentrate.
9. The method of claim 8, wherein during the further processing stage, the middling fraction from the rougher and the tailings fraction from the cleaner shaker are also treated.
10. The method of claim 8, wherein the further processing stage comprises a roughing wet magnetic separator receiving material from the shaker stage.
11. The method of claim 10, wherein the rougher wet magnetic separator of the further processing stage receives middling fraction from a rougher cradle, middling fraction from a cleaner cradle, and tailings fraction from a cleaner cradle.
12. The method of claim 8, wherein the further processing stage comprises: a clean wet magnetic separator that receives magnetic material from the roughing wet magnetic separator and discharges non-magnetic material from the roughing magnetic separator as tailings.
13. The method of claim 12, the method comprising: in the further processing stage, the magnetic material from the clean wet magnetic separator is dewatered and the dewatered magnetic material from the clean wet magnetic separator is recycled to the clean shaker.
14. The process of claim 1, wherein the wet spiral separator or wet spiral concentrator is constructed and operated to cause Cr of the first tailings stream 2 O 3 The content is less than 8 mass% on a dry basis.
15. The method of claim 1, wherein more than 50%, or more than 60%, or more than 70%, or more than 80% of chromite fines in the feed slurry fed to the wet spiral beneficiation stage are-75 μm of material.
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| ZA201901722 | 2019-03-20 | ||
| ZA2019/01722 | 2019-03-20 | ||
| PCT/IB2020/051627 WO2020188379A1 (en) | 2019-03-20 | 2020-02-26 | Recovery of chromite fines |
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| CN113631739A CN113631739A (en) | 2021-11-09 |
| CN113631739B true CN113631739B (en) | 2024-03-22 |
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| EP (1) | EP3914740B1 (en) |
| CN (1) | CN113631739B (en) |
| CY (1) | CY1126134T1 (en) |
| DK (1) | DK3914740T3 (en) |
| EA (1) | EA202192514A1 (en) |
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| CN113117880A (en) * | 2021-04-08 | 2021-07-16 | 河北钢铁集团矿业有限公司 | Beneficiation process and beneficiation system for high-vanadium titano-magnetite |
| CN113941441A (en) * | 2021-10-14 | 2022-01-18 | 中钢集团马鞍山矿山研究总院股份有限公司 | Wet-type strong magnetic preselection method for low-grade chromite |
| CN116943856B (en) * | 2023-09-20 | 2023-11-28 | 矿冶科技集团有限公司 | Method for effectively recovering chromite |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4295881A (en) * | 1979-04-23 | 1981-10-20 | Texasgulf Inc. | Process for extraction of platinum group metals from chromite-bearing ore |
| CN101890394A (en) * | 2009-05-23 | 2010-11-24 | 魏子贺 | Ore dressing process for weakly magnetic iron ore |
| JP2014196569A (en) * | 2014-06-05 | 2014-10-16 | 住友金属鉱山株式会社 | Chromite recovery method |
| CN206965906U (en) * | 2017-07-24 | 2018-02-06 | 大连地拓环境科技有限公司 | A kind of iron tailings recycling treatment system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3323900A (en) | 1964-08-13 | 1967-06-06 | Fuji Iron & Steel Co Ltd | Process for treatment of iron oxide ores containing nickel, chromium and cobalt |
| US3935094A (en) | 1974-10-10 | 1976-01-27 | Quebec Iron And Titanium Corporation - Fer Et Titane Du Quebec, Incorporated | Magnetic separation of ilmenite |
| US4059506A (en) * | 1975-05-23 | 1977-11-22 | United States Steel Corporation | Ore tailings treatment |
| RU2208060C2 (en) | 2001-05-23 | 2003-07-10 | Калмукшев Сатвалде Ромазанович | Method for producing chromite concentrates from lean disseminated chrome iron bearing ores |
| ZA200503034B (en) | 2004-04-19 | 2005-12-28 | Paul Kruger Family Trust | Beneficiation of chromite ore |
| CN201366374Y (en) | 2008-12-30 | 2009-12-23 | 中国恩菲工程技术有限公司 | Laterite chromium-separating facility |
| CN101823018B (en) | 2009-03-05 | 2013-03-06 | 中国恩菲工程技术有限公司 | Method for selecting chromium from laterite |
| ZA201404437B (en) | 2013-03-19 | 2015-08-26 | Khulasonke Transp Cc | A method of treating a chromite containing material |
| EA033243B1 (en) * | 2014-06-02 | 2019-09-30 | Минтек | Smelting of low grade chromite concentrate fines |
-
2020
- 2020-02-26 EA EA202192514A patent/EA202192514A1/en unknown
- 2020-02-26 WO PCT/IB2020/051627 patent/WO2020188379A1/en active Search and Examination
- 2020-02-26 EP EP20712025.4A patent/EP3914740B1/en active Active
- 2020-02-26 CN CN202080023373.4A patent/CN113631739B/en active Active
- 2020-02-26 FI FIEP20712025.4T patent/FI3914740T3/en active
- 2020-02-26 DK DK20712025.4T patent/DK3914740T3/en active
- 2020-02-26 ES ES20712025T patent/ES2953087T3/en active Active
- 2020-02-26 ZA ZA2020/01193A patent/ZA202001193B/en unknown
-
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4295881A (en) * | 1979-04-23 | 1981-10-20 | Texasgulf Inc. | Process for extraction of platinum group metals from chromite-bearing ore |
| CN101890394A (en) * | 2009-05-23 | 2010-11-24 | 魏子贺 | Ore dressing process for weakly magnetic iron ore |
| JP2014196569A (en) * | 2014-06-05 | 2014-10-16 | 住友金属鉱山株式会社 | Chromite recovery method |
| CN206965906U (en) * | 2017-07-24 | 2018-02-06 | 大连地拓环境科技有限公司 | A kind of iron tailings recycling treatment system |
Non-Patent Citations (1)
| Title |
|---|
| N.N.Grishin等.Primary processing of chromite ores and ore-preparation of wastes for production of refractory materials.《Journal of Mining Science》.2004,第40卷(第4期),正文第5-6段. * |
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| WO2020188379A1 (en) | 2020-09-24 |
| EA202192514A1 (en) | 2021-12-13 |
| DK3914740T3 (en) | 2023-08-14 |
| EP3914740A1 (en) | 2021-12-01 |
| CN113631739A (en) | 2021-11-09 |
| CY1126134T1 (en) | 2023-11-15 |
| EP3914740B1 (en) | 2023-05-17 |
| ZA202001193B (en) | 2022-05-25 |
| ES2953087T3 (en) | 2023-11-08 |
| FI3914740T3 (en) | 2023-08-17 |
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