A method for processing high-iron bauxite

Abstract

The application relates to the technical field of mineral pretreatment, in particular to a treatment method of high-iron bauxite; the treatment method comprises the following steps: performing selective crushing and grinding treatment and grading treatment on the high-iron bauxite to obtain coarse-grained bauxite and fine-grained bauxite; performing first and second heavy separation impurity removal on the coarse-grained bauxite to obtain heavy separation concentrate, heavy separation middlings and heavy separation tailings; performing grinding and magnetic separation treatment on the heavy separation concentrate to obtain magnetic separation concentrate and magnetic separation tailings; performing centrifugal ore dressing impurity removal treatment on the fine-grained bauxite to obtain centrifugal concentrate and centrifugal tailings; mixing the heavy separation middlings, the magnetic separation tailings and the centrifugal concentrate to obtain product concentrate; mixing the heavy separation tailings and the centrifugal tailings to obtain product tailings; the overall method has the characteristics of short process, low energy consumption, low production cost, low investment, high ore dressing efficiency and the like, and the obtained aluminum concentrate is suitable for Bayer process production of aluminum oxide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mineral pretreatment, and particularly relates to a processing method of high-iron bauxite. BACKGROUND

[0002] With the rapid development of economy and the alumina industry, the demand for bauxite resources in China is growing rapidly at present. However, the domestic bauxite reserves only account for 3.3% of the global reserves, and the quality is poor, which cannot meet the demand of alumina production. In recent years, the demand for imported ore has been rising and showing a trend of continuous growth, which makes the dependence on foreign ore gradually increase, and the risk faced by domestic alumina production is getting bigger and bigger.

[0003] At present, the direct Bayer process of high-iron bauxite to produce alumina will cause the scabbing of alumina process, the increase of alkali consumption and ore consumption, thereby increasing the production cost of alumina, increasing the amount of red mud, and affecting the quality of alumina. Therefore, it is particularly important to develop a bauxite impurity removal technology. At present, the conventional high-iron bauxite bauxite impurity removal technology mainly includes acid leaching + roasting process and magnetic separation + flotation desilication process. However, due to the high cost of these beneficiation processes and the poor adaptability to ore, the ore processing process is too long, which cannot meet the current tight ore situation and the economic and technical requirements of alumina enterprises for high-iron bauxite. Therefore, how to provide a simple process and low-cost processing method for high-iron bauxite is a technical problem to be solved at present. SUMMARY

[0004] The present application provides a processing method of high-iron bauxite to solve the technical problems of high cost and long process in the prior art processing method of high-iron bauxite.

[0005] In a first aspect, the present application provides a processing method of high-iron bauxite, which comprises:

[0006] The high-iron bauxite is subjected to selective crushing and grinding treatment and grading treatment to obtain coarse-grained bauxite and fine-grained bauxite, respectively;

[0007] The coarse-grained bauxite is subjected to first gravity separation and second gravity separation to obtain gravity separation concentrate, gravity separation middlings and gravity separation tailings, respectively;

[0008] The gravity separation concentrate is subjected to grinding and magnetic separation treatment to obtain magnetic separation concentrate and magnetic separation tailings, respectively;

[0009] The fine-grained bauxite is subjected to centrifugal beneficiation for impurity removal treatment to obtain centrifugal concentrate and centrifugal tailings, respectively;

[0010] The gravity separation middlings, the magnetic separation tailings and the centrifugal concentrate are mixed to obtain product concentrate;

[0011] mixing the re-election tailings and the centrifugal tailings to obtain product tailings.

[0012] Optionally, the target impurity of the first re-election impurity removal is a silicon mineral, and the separation density of the first re-election impurity removal is 2.2 g / cm 3 ~ 2.8 g / cm 3 , and the feeding pressure of the first re-election impurity removal is 0.1 Mpa ~ 0.5 Mpa.

[0013] Optionally, the target impurity of the second re-election impurity removal is an iron mineral, and the separation density of the second re-election impurity removal is 2.8 g / cm 3 ~ 3.5 g / cm 3 , and the feeding pressure of the second re-election impurity removal is 0.15 Mpa ~ 0.5 Mpa.

[0014] Optionally, the target impurity of the impurity removal treatment is a silicon mineral, and the separation density of the impurity removal treatment is 2.5 g / cm 3 ~ 3.2 g / cm 3 .

[0015] Optionally, the medium of the first re-election impurity removal and the second re-election impurity removal respectively includes at least one of water, a saturated calcium chloride solution and a sodium silicate solution; and / or,

[0016] The heavy medium of the first re-election impurity removal and the second re-election impurity removal respectively includes magnetite and / or ferrosilicon; and / or,

[0017] The particle size of the magnetite and the ferrosilicon is respectively < 0.038 mm.

[0018] Optionally, the impurity removal medium of the centrifugal beneficiation includes at least one of water, a saturated calcium chloride solution and a sodium silicate solution; and / or,

[0019] The heavy medium of the centrifugal beneficiation includes ferrosilicon; and / or,

[0020] The particle size of the ferrosilicon is < 0.038 mm.

[0021] Optionally, the grinding includes wet grinding, and the weight content of the target bauxite ore with a particle size of ≤ 0.074 mm is 80% ~ 95%.

[0022] Optionally, the magnetic field strength of the magnetic separation is 0.2 TT ~ 1.2 T, and the number of times of the magnetic separation is 1 ~ 3 times.

[0023] Optionally, the particle size D of the coarse bauxite ore satisfies: n ≤ D ≤ 10 mm;

[0024] The particle size d of the fine bauxite meets: 0mm≤d≤n;

[0025] The value of n is 0.074mm-1mm.

[0026] Optionally, n is the particle size boundary value of the coarse bauxite and the fine bauxite.

[0027] The above technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0028] The processing method of high-iron bauxite provided by the embodiments of the present application first performs selective crushing and grinding treatment and grading treatment on the high-iron bauxite to obtain coarse bauxite and fine bauxite, performs first gravity separation and second gravity separation on the coarse bauxite to obtain gravity separation concentrate, gravity separation middlings and gravity separation tailings, performs grinding and magnetic separation treatment on the gravity separation concentrate to obtain magnetic separation concentrate and magnetic separation tailings, performs gravity separation treatment on the fine bauxite to obtain centrifugal concentrate and centrifugal tailings, mixes the magnetic separation tailings, the gravity separation middlings and the centrifugal concentrate to obtain product aluminum concentrate, mixes the gravity separation tailings and the centrifugal tailings to obtain product tailings, and the magnetic separation concentrate is product iron concentrate. Through the above steps, the high-iron bauxite can be processed simply, and only selective crushing and grinding treatment, grading treatment, first gravity separation, second gravity separation, grinding, magnetic separation and centrifugal separation are needed to obtain product aluminum concentrate, product tailings and product iron concentrate at low cost. Therefore, the overall method has the characteristics of short process, low energy consumption, low production cost, low investment, high beneficiation efficiency, etc., and the obtained aluminum concentrate is suitable for the production of aluminum oxide by the Bayer process. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate preferred embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0031] Figure 1 The flowchart of the processing method of high-iron bauxite provided by the embodiments of the present application. DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0033] Unless otherwise specifically indicated, all the various raw materials, reagents, instruments, and equipment used in the present application can be purchased from the market or prepared by existing methods.

[0034] As shown in the following Figure 1 The embodiments of the present application provide a processing method of high-iron bauxite, and the processing method comprises the following steps:

[0035] S1. Selective crushing and grinding treatment and grading treatment are performed on the high-iron bauxite to obtain coarse-grained bauxite and fine-grained bauxite respectively;

[0036] S2. First and second gravity separation are performed on the coarse-grained bauxite to obtain gravity separation concentrate, gravity separation middlings, and gravity separation tailings respectively;

[0037] S3. Grinding and magnetic separation treatment are performed on the gravity separation concentrate to obtain magnetic separation concentrate and magnetic separation tailings respectively;

[0038] S4. Centrifugal separation is performed on the fine-grained bauxite to obtain centrifugal separation concentrate and centrifugal separation tailings respectively;

[0039] S5. The gravity separation middlings, the magnetic separation tailings, and the centrifugal separation concentrate are mixed to obtain product concentrate;

[0040] S6. The gravity separation tailings and the centrifugal separation tailings are mixed to obtain product tailings.

[0041] In the embodiments of the present application, the useful minerals in the high-iron bauxite are diaspore (monohydrate hard aluminum stone, monohydrate soft aluminum stone, and trihydrate aluminum stone), the gangue minerals are kaolinite, illite, pyrophyllite, chlorite, quartz, and calcite, and the iron minerals are hematite and limonite.

[0042] The crushing equipment in the selective crushing and grinding treatment comprises a jaw crusher and a roller crusher, and the grading equipment in the grading treatment comprises a grader, a cyclone, a linear screen, and a high-frequency screen. The crushing equipment is a combination of the jaw crusher and the roller crusher, the crushing process is two-stage closed circuit, and the crushing particle size is 100% of the particle size of 10 mm or less. The grading equipment is a combination of the grader, the cyclone, the linear screen, and the high-frequency screen, and the grading particle size is 1 mm to 0.074 mm.

[0043] In some alternative embodiments, the target impurity of the first gravity separation is a silicon mineral, the separation density of the first gravity separation is 2.2 g / cm 3 ~ 2.8 g / cm 3 , and the feeding pressure of the first gravity separation is 0.1 Mpa ~ 0.5 Mpa.

[0044] In some alternative embodiments, the target impurity of the second gravity separation is an iron mineral, the separation density of the second gravity separation is 2.8 g / cm 3 ~ 3.5 g / cm 3 , and the feeding pressure of the second gravity separation is 0.15 Mpa ~ 0.5 Mpa.

[0045] In the embodiments of the present application, the target impurity and the specific separation density of the first gravity separation and the second gravity separation are controlled, and since the first gravity separation and the second gravity separation are performed by using two-stage series heavy medium cyclones, the separation between the gravity separation concentrate, the gravity separation middlings and the gravity separation tailings can be complete; if the separation density is low, at this time, the un-dissociated minerals such as diaspore, silicate minerals and iron minerals will be left in the gravity separation middlings, resulting in a low grade of the gravity separation middlings, thereby affecting the separation index.

[0046] The heavy medium cyclone is a two-product heavy medium cyclone.

[0047] The specific feeding pressure of the first gravity separation and the second gravity separation is controlled, so that the separation of the first gravity separation and the second gravity separation is sufficient; when the feeding pressure is insufficient, the centrifugal force of the first gravity separation and the second gravity separation will be reduced, the separation of the aluminum minerals and other impurity minerals cannot be well realized, and the separation index will be affected.

[0048] In some alternative embodiments, the target impurity of the impurity removal treatment is a silicon mineral, the separation density of the impurity removal treatment is 2.5 g / cm 3 ~ 3.2 g / cm 3 .

[0049] In the embodiments of the present application, the specific target impurity and the specific separation density of the impurity removal treatment are controlled, so that the separation between the concentrate and the tailings can be sufficient; if under the condition of a low separation density, the centrifugal beneficiation can only take out part of the completely dissociated silicate minerals with the tailings, while the un-dissociated minerals such as the silicate minerals, diaspore and iron minerals, titanium minerals are left in the concentrate, resulting in a low grade of the concentrate.

[0050] In some alternative embodiments, the medium of the first gravity separation and the medium of the second gravity separation respectively include at least one of water, a saturated calcium chloride solution and a sodium silicate solution; and / or,

[0051] The specific medium and the specific weighting medium of the first reselection impurity removal include magnetite and / or ferrosilicon; and / or,

[0052] The particle size of the magnetite and the ferrosilicon is less than 0.038 mm.

[0053] In the embodiments of the present application, the specific medium and the specific weighting medium of the first reselection impurity removal are controlled so that the mass ratio of the medium to the weighting medium used in the first reselection impurity removal is 1:1.5-1:3.0.

[0054] The specific medium and the specific weighting medium of the second reselection impurity removal are controlled so that the mass ratio of the medium to the weighting medium used in the second reselection impurity removal is 1.25-1:5.5.

[0055] Generally, the reselection concentrate mainly contains iron minerals (hematite and limonite); the reselection middlings mainly contain diaspore (diaspore and gibbsite), which is suitable for the production of alumina by the Bayer process; and the reselection tailings mainly contain kaolinite, illite, quartz and calcite, which can be used as ceramic materials and building cement raw materials.

[0056] In some optional embodiments, the medium for the centrifugal ore dressing includes at least one of water, a saturated calcium chloride solution and a sodium silicate solution; and / or,

[0057] The weighting medium for the centrifugal ore dressing includes ferrosilicon; and / or,

[0058] The particle size of the ferrosilicon is less than 0.038 mm.

[0059] In the embodiments of the present application, the specific medium and the specific weighting medium of the centrifugal ore dressing are controlled so that the mass ratio of the medium to the weighting medium is 1:2.3-1:5.1.

[0060] The equipment used for the centrifugal ore dressing is a water jacket type centrifuge.

[0061] Generally, the centrifugal concentrate mainly contains diaspore (diaspore and gibbsite), which is suitable for the production of alumina by the Bayer process; and the centrifugal tailings mainly contain kaolinite, illite, quartz and calcite, which can be used as ceramic materials and building cement raw materials.

[0062] In some optional embodiments, the grinding includes wet grinding, and the target bauxite for the grinding has a weight content of 80%-95% of mineral materials with a particle size of less than or equal to 0.074 mm.

[0063] In the embodiment of the present application, controlling the specific weight content of the ore with a particle size of ≤0.074 mm and the specific grinding method in the target bauxite for grinding is beneficial to better monomer dissociation of iron minerals and aluminum minerals in the bauxite, and provides favorable conditions for magnetic separation; if the content is too large, over-crushing of the ore will occur, resulting in the inclusion of non-magnetic minerals during the magnetic separation process, thereby affecting the yield of the magnetic separation tailings, and also increasing the energy consumption of grinding. The adverse effect of taking the content too small is incomplete dissociation of iron-containing minerals and useful aluminum-containing minerals, and poor magnetic separation effect of iron removal.

[0064] In some optional embodiments, the magnetic field strength of the magnetic separation is 0.2TT to 1.2T, and the number of magnetic separations is 1 to 3 times.

[0065] In the embodiment of the present application, controlling the specific magnetic field intensity and the specific number of magnetic separations can be beneficial to the magnetic separation of iron-containing minerals and reduce the iron content in the magnetic separation tailings as much as possible; the adverse effect of an excessively large intensity value is that it leads to a reduced yield of magnetic separation tailings and the loss of aluminum minerals in the magnetic separation concentrate, and the adverse effect of an excessively small intensity value is that it is insufficient to achieve the magnetic separation of iron minerals and aluminum-containing minerals, resulting in a higher iron content in the magnetic separation tailings.

[0066] The equipment used for magnetic separation includes at least one of a CS type wet electromagnetic induction roller strong magnetic field magnetic separator, a wet double vertical ring strong magnetic field magnetic separator and a SLon type vertical ring pulsating high gradient magnetic separator.

[0067] In some optional embodiments, the particle size D of the coarse-grained bauxite satisfies: n≤D≤10 mm;

[0068] The particle size d of the fine-grained bauxite satisfies: 0 mm ≤ d ≤ n;

[0069] Among them, the value of n is 0.074mm~1mm.

[0070] In some optional embodiments, n is the particle size dividing value between the coarse-grained bauxite and the fine-grained bauxite.

[0071] In the embodiments of the present application, the specific particle size dividing value of coarse-grained bauxite and fine-grained bauxite is controlled. Due to the complex interpenetration relationship of different minerals in bauxite, under coarser particle size conditions, the minerals are not fully dissociated, resulting in a high aluminum-silicon ratio in the tailings and a low aluminum-silicon ratio in the concentrate during the sorting process, which directly affects the sorting effect.

[0072] By controlling the particle size cutoff value between 0.074mm and 1mm, the particle size entering the heavy medium cyclone and centrifugal concentrator can be increased, thereby directly affecting the indicators of the final product.

[0073] The present application is further described below in connection with specific examples. It is understood that these examples are merely for illustrative purposes and do not limit the scope of the present application. The experimental methods in the following examples, if not specified, are generally determined according to the national standards. If there is no corresponding national standard, the general international standards, conventional conditions, or the conditions recommended by the manufacturer are used.

[0074] Example 1

[0075] The high-iron bauxite is selected, and the chemical composition includes, in mass fraction: Al2O3: 48.51%, SiO2: 12.56%, Fe2O3: 20.23%, and the Al:Si ratio is 3.86.

[0076] As shown in Figure 1 , the treatment process of the high-iron bauxite treatment method includes:

[0077] The raw ore is crushed and classified to obtain a crushed product less than 10 mm, and the crushed product is classified into 1 mm size fraction. The -10 mm±1 mm size fraction is separated by a two-stage series heavy medium cyclone under the conditions that the separation density of the first heavy impurity removal is 2.30 g / cm 3 and the separation density of the second heavy impurity removal is 2.90 g / cm 3 , to obtain a heavy separation concentrate, a heavy separation middling, and a heavy separation tailing.

[0078] The heavy separation concentrate is subjected to magnetic separation by a SLon type vertical ring pulsating high gradient magnetic separator under the conditions that the grinding fineness is 90% and the magnetic separation field strength is 0.3 T, to obtain a magnetic separation concentrate and a magnetic separation tailing.

[0079] The -1 mm size fraction is separated by a centrifugal concentrator under the conditions that the heavy liquid density of the saturated calcium chloride solution and the silicon iron is 2.60 g / cm 3 , to obtain a centrifugal concentrate and a centrifugal tailing.

[0080] The heavy separation middling, the magnetic separation tailing, and the centrifugal concentrate are combined as an aluminum concentrate, the heavy separation tailing and the centrifugal tailing are combined as a tailing, and the magnetic separation concentrate is an iron concentrate.

[0081] Example 2

[0082] The high-iron bauxite is selected, and the chemical composition includes, in mass fraction: Al2O3: 43.67%, SiO2: 15.32%, Fe2O3: 22.18%, and the Al:Si ratio is 2.85.

[0083] As shown in Figure 1 , the treatment process of the high-iron bauxite treatment method includes:

[0084] The raw ore is crushed and classified to obtain a crushed product less than 10 mm, the crushed product is classified in 0.2 mm size fraction, the -10 mm ± 0.5 mm size fraction is separated by the first heavy separation impurity removal with water and ferrosilicon configured separation density of 2.20 g / cm 3 and the second heavy separation impurity removal with separation density of 2.80 g / cm 3 , the feeding pressure of the first heavy medium cyclone and the second heavy medium cyclone is 0.15 Mpa and 0.25 Mpa respectively, to obtain the heavy separation concentrate, the heavy separation middlings and the heavy separation tailings;

[0085] The heavy separation concentrate is subjected to magnetic separation by the SLon type vertical ring pulsating high gradient magnetic separator under the conditions of grinding fineness of 85% and magnetic separation field strength of 0.5 T, to obtain the magnetic separation concentrate and the magnetic separation tailings;

[0086] The -0.5 mm size fraction is separated by the centrifugal concentrator under the conditions of the heavy liquid density of 2.80 g / cm 3 configured by the saturated calcium chloride solution and ferrosilicon, to obtain the centrifugal concentrate and the centrifugal tailings;

[0087] The heavy separation middlings, the magnetic separation tailings and the centrifugal concentrate are combined as the aluminum concentrate, the heavy separation tailings and the centrifugal tailings are combined as the tailings, and the magnetic separation concentrate is the iron concentrate.

[0088] Example 3

[0089] The high-iron bauxite is selected, and the chemical components include, in mass fraction: Al2O3: 41.87%, SiO2: 14.38%, Fe2O3: 25.76%, and the Al:Si ratio is 2.91.

[0090] As shown in Figure 1 , the processing flow of the high-iron bauxite processing method includes:

[0091] The raw ore is crushed and classified to obtain a crushed product less than 10 mm, the crushed product is classified in 0.074 mm size fraction, the -10 mm ± 0.2 mm size fraction is separated by the first heavy separation impurity removal with water and ferrosilicon configured separation density of 2.5 g / cm 3 and the second heavy separation impurity removal with separation density of 3.0 g / cm 3 , the feeding pressure of the first heavy medium cyclone and the second heavy medium cyclone is 0.1 Mpa and 0.2 Mpa respectively, to obtain the heavy separation concentrate, the heavy separation middlings and the heavy separation tailings;

[0092] The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as an aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as a tailings, and the magnetic separation concentrate is an iron concentrate.

[0093] The -0.2 mm size fraction is separated by a centrifugal separator under the condition that the heavy medium density is 2.95 g / cm 3 , the calcium chloride saturated solution and ferrosilicon are configured, to obtain a centrifugal concentrate and a centrifugal tailings.

[0094] The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as an aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as a tailings, and the magnetic separation concentrate is an iron concentrate.

[0095] Example 4

[0096] The high-iron bauxite is selected, and the chemical components include, in mass fraction, Al2O3: 38.47%, SiO2: 18.21%, Fe2O3: 23.18%, and the Al:Si ratio is 2.11.

[0097] As shown in Figure 1 , the processing flow of the high-iron bauxite processing method includes:

[0098] The raw ore is crushed and classified to obtain a crushed product less than 10 mm, and the crushed product is classified by a 0.074 mm size fraction, the -10 mm±0.074 mm size fraction is separated by a two-stage series heavy medium cyclone under the condition that the separation density of the first gravity separation impurity removal is 2.3 g / cm 3 and the separation density of the second gravity separation impurity removal is 3.30 g / cm 3 , to obtain a gravity separation concentrate, a gravity separation middlings and a gravity separation tailings;

[0099] The gravity separation concentrate is subjected to magnetic separation by a SLon type vertical ring pulsating high gradient magnetic separator under the condition that the grinding fineness is 85% and the magnetic field strength is 0.2T, to obtain a magnetic separation concentrate and a magnetic separation tailings.

[0100] The -0.074 mm size fraction is separated by a centrifugal separator under the condition that the heavy medium density is 3.0 g / cm 3 , the calcium chloride saturated solution and ferrosilicon are configured, to obtain a centrifugal concentrate and a centrifugal tailings.

[0101] The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as an aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as a tailings, and the magnetic separation concentrate is an iron concentrate.

[0102] Comparative Example 1

[0103] Comparative Example 1 and Example 1 are compared, and the difference between Comparative Example 1 and Example 1 is that:

[0104] The specific composition of the high-iron bauxite is the same as that of Example 1.

[0105] The raw ore is subjected to crushing-classification treatment to obtain a crushed product less than 10 mm, and the crushed product is classified by 3 mm particle size, and the -10 mm ± 3 mm particle size is subjected to separation at a separation density of 2.30 g / cm 3 and 2.90 g / cm 3 in the first and second heavy-medium separation of water and ferrosilicon configuration, and the feeding pressures of the first and second heavy-medium cyclones are 0.1 Mpa and 0.2 Mpa respectively, to obtain a heavy separation concentrate, a heavy separation middling and a heavy separation tailing;

[0106] The heavy separation concentrate is subjected to magnetic separation by a SLon type vertical ring pulsating high gradient magnetic separator under the conditions of a grinding fineness of 90% and a magnetic separation field strength of 0.3 T, to obtain a magnetic separation concentrate and a magnetic separation tailing;

[0107] The -3 mm particle size is subjected to separation by a centrifugal concentrator under the conditions of a heavy liquid density of 2.60 g / cm 3 of a saturated calcium chloride solution and ferrosilicon configuration, to obtain a centrifugal concentrate and a centrifugal tailing;

[0108] The heavy separation middling, the magnetic separation tailing and the centrifugal concentrate are combined as an aluminum concentrate, the heavy separation tailing and the centrifugal tailing are combined as a tailing, and the magnetic separation concentrate is an iron concentrate.

[0109] Comparative Example 2

[0110] Comparative Example 2 and Example 1 are compared, and the difference between Comparative Example 2 and Example 1 is that:

[0111] The specific composition of the high-iron bauxite is the same as that of Example 1.

[0112] The raw ore is subjected to crushing-classification treatment to obtain a crushed product less than 10 mm, and the crushed product is classified by 1 mm particle size, and the -10 mm ± 1 mm particle size is subjected to separation at a separation density of 2.30 g / cm 3 and 2.90 g / cm 3 in the first and second heavy-medium separation of water and ferrosilicon configuration, and the feeding pressures of the first and second heavy-medium cyclones are 0.05 Mpa and 0.15 Mpa respectively, to obtain a heavy separation concentrate, a heavy separation middling and a heavy separation tailing;

[0113] The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as the aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as the tailings, and the magnetic separation concentrate is the iron concentrate.

[0114] The -1 mm size fraction is separated by a centrifugal separator under the condition that the heavy medium density is 2.60 g / cm 3 The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as the aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as the tailings, and the magnetic separation concentrate is the iron concentrate.

[0115] The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as the aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as the tailings, and the magnetic separation concentrate is the iron concentrate.

[0116] Comparative Example 3

[0117] Comparative Example 3 and Example 1 are compared, and the difference between Comparative Example 3 and Example 1 is that:

[0118] The specific composition of the high-iron bauxite is the same as that of Example 1.

[0119] The raw ore is crushed and classified to obtain a crushed product less than 10 mm, and the crushed product is classified into 1 mm size fractions. The -10 mm ± 1 mm size fraction is separated by a two-stage series heavy medium cyclone under the condition that the separation density of the first gravity separation impurity removal is 2.00 g / cm 3 and the separation density of the second gravity separation impurity removal is 2.60 g / cm 3 The feeding pressures of the first heavy medium cyclone and the second heavy medium cyclone are 0.1 Mpa and 0.2 Mpa respectively, to obtain gravity separation concentrate, gravity separation middlings and gravity separation tailings.

[0120] The gravity separation middlings are subjected to magnetic separation by a SLon vertical ring pulsating high gradient magnetic separator under the condition that the grinding fineness is 90% and the magnetic field strength is 0.3 T, to obtain magnetic separation concentrate and magnetic separation tailings.

[0121] The -1 mm size fraction is separated by a centrifugal separator under the condition that the heavy medium density is 2.60 g / cm 3 The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as the aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as the tailings, and the magnetic separation concentrate is the iron concentrate.

[0122] The gravity separation middlings, the magnetic separation tailings and the centrifugal separation concentrate are combined as the aluminum concentrate, the gravity separation tailings and the centrifugal separation tailings are combined as the tailings, and the magnetic separation concentrate is the iron concentrate.

[0123] Comparative Example 4

[0124] Comparative Example 4 and Example 1 are compared, and the difference between Comparative Example 4 and Example 1 is that:

[0125] The specific composition of the high-iron bauxite is the same as that of Example 1.

[0126] The raw ore is crushed and classified to obtain a crushed product less than 10 mm, and the crushed product is classified into 1 mm size fraction, and the -10 mm ±1 mm size fraction is separated by a two-stage series connection type dense medium cyclone under the conditions that the separation density of the first heavy separation is 2.30 g / cm 3 and the separation density of the second heavy separation is 2.90 g / cm 3 , the feeding pressure of the first heavy medium cyclone and the second heavy medium cyclone is 0.1 Mpa and 0.2 Mpa respectively, to obtain a heavy separation concentrate, a heavy separation middling and a heavy separation tailing;

[0127] The heavy separation concentrate is subjected to magnetic separation by a SLon type vertical ring pulsating high gradient magnetic separator under the conditions that the grinding fineness is 80% and the magnetic field strength is 0.15 T, to obtain a magnetic separation concentrate and a magnetic separation tailing;

[0128] The -1 mm size fraction is separated by a centrifugal concentrator under the conditions that the heavy medium density of the saturated calcium chloride solution and the ferrosilicon is 2.60 g / cm 3 , to obtain a centrifugal concentrate and a centrifugal tailing;

[0129] The heavy separation middling, the magnetic separation tailing and the centrifugal concentrate are combined as an aluminum concentrate, the heavy separation tailing and the centrifugal tailing are combined as a tailing, and the magnetic separation concentrate is an iron concentrate.

[0130] Related experiments and effect data:

[0131] The products obtained in Examples 1 to 4 and Comparative Examples 1 to 4 are compared and analyzed, and the results are shown in Table 1.

[0132] Table 1: Conditions of products obtained in each example and comparative example

[0133]

[0134] From the data in Table 1, it can be seen that:

[0135] From the data of Comparative Example 1 and Comparative Example 1, it can be seen that increasing the crushing particle size and increasing the particle size entering the heavy medium cyclone and the centrifugal machine will directly affect the final heavy separation index, mainly because the embedding relationship of aluminum minerals, silicon minerals and iron minerals in the bauxite is complex, and under the condition of relatively coarse particle size, the mineral dissociation is not sufficient, the tailing aluminum-silicon ratio is high during the separation process, and the aluminum concentrate aluminum-silicon ratio is low, which directly affects the separation effect.

[0136] From the data comparison of Example 1 and Comparative Example 2, it can be seen that reducing the feeding pressure of the heavy medium cyclone will directly affect the separation index, mainly because the feeding pressure is insufficient, the centrifugal force is low, and the separation of aluminum minerals and other impurity minerals cannot be well achieved.

[0137] From the data comparison of Example 1 and Comparative Example 3, it can be seen that reducing the separation density of the dense medium cyclone and the centrifuge will directly affect the separation index, mainly because under the condition of lower separation density, gibbsite will remain in the aluminum concentrate with silicate minerals and iron minerals that are not dissociated, resulting in a lower grade of aluminum concentrate.

[0138] From the data comparison of Example 1 and Comparative Example 4, it can be seen that reducing the grinding fineness and the magnetic field strength of the magnetic separator affects the separation index of the magnetic separation concentrate and the magnetic separation tailings, mainly because the grinding fineness is too low, which will lead to incomplete dissociation of iron-containing minerals and aluminum-containing useful minerals, and the separation effect of magnetic separation for iron removal is poor; the magnetic field strength of the magnetic separator is too low, which is not enough to realize the magnetic separation of iron minerals and aluminum-containing minerals, resulting in a lower iron content of the iron concentrate.

[0139] In summary, by using the method provided in the embodiments of the present application, based on the process flow of "crushing-classification-dense medium beneficiation desilication-magnetic separation iron removal-fine particle centrifugal beneficiation desilication", after processing the high-aluminum bauxite, tailings with high silicon mineral content and relatively low aluminum-silicon ratio, aluminum concentrate with high recovery rate of alumina and iron concentrate that can be directly sold are obtained, which has the characteristics of short beneficiation process, low beneficiation cost, low investment, high beneficiation efficiency, and the aluminum concentrate is suitable for producing alumina by Bayer process, and the iron concentrate can be directly sold as a product, and the tailings are suitable for being used as building materials and ceramic raw materials. Therefore, the available resource reserves of the bauxite industry can be expanded, and the utilization rate of bauxite resources in the bauxite industry can be comprehensively improved, which is of great significance to the sustainable development of the aluminum industry.

[0140] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, regardless of the range. In addition, whenever a numerical range is indicated in this text, it refers to any cited number (fraction or integer) within the indicated range.

[0141] In this application, unless otherwise specified, the directional words used, such as "upper" and "lower", refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of the present application specification, the terms "including", "comprising", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this article, "at least one" refers to one or more, and "plurality" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple.

[0142] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for processing high iron bauxite, characterized in that: The processing method comprises: The high iron bauxite is selectively crushed and graded to obtain coarse-grained bauxite and fine-grained bauxite respectively; Performing a first gravity separation and a second gravity separation on the coarse-grained bauxite to remove impurities, thereby obtaining a gravity separation concentrate, a gravity separation middling, and a gravity separation tailings, respectively; Grinding and magnetic separation are performed on the gravity separation concentrate to obtain magnetic separation concentrate and magnetic separation tailings, respectively; The fine-grained bauxite is subjected to impurity removal treatment by centrifugal separation to obtain centrifugal concentrate and centrifugal tailings respectively; Mixing the gravity separation ore, the magnetic separation tailings and the centrifugal concentrate to obtain a product concentrate; The gravity separation tailings and the centrifugal tailings are mixed to obtain product tailings.

2. The processing method according to claim 1, characterized in that The target impurities of the first gravity separation are silicon minerals, and the separation density of the first gravity separation is 2.2 g / cm 3 ~2.8g / cm 3 The feeding pressure of the first gravity separation impurity removal is 0.1Mpa~0.5Mpa.

3. The processing method according to claim 1, characterized in that The target impurities of the second gravity separation are iron minerals, and the separation density of the second gravity separation is 2.8g / cm 3 ~3.5g / cm 3 The feeding pressure of the second gravity separation impurity removal is 0.15Mpa~0.5Mpa.

4. The processing method according to claim 1, characterized in that The target impurities of the impurity removal treatment are silicon minerals, and the sorting density of the impurity removal treatment is 2.5g / cm 3 ~3.2g / cm 3 .

5. The processing method according to claim 1, characterized in that The medium for the first gravity separation and the second gravity separation respectively comprises at least one of water, a saturated calcium chloride solution and a sodium silicate solution; and / or, The weighting media for the first gravity separation and the second gravity separation respectively include magnetite and / or ferrosilicon; and / or, The particle sizes of the magnetite and the ferrosilicon are respectively less than 0.038 mm.

6. The processing method according to claim 1, characterized in that The impurity removal medium of the centrifugal beneficiation comprises at least one of water, a saturated calcium chloride solution and a sodium silicate solution; and / or, The weighting medium of the centrifugal beneficiation comprises ferrosilicon; and / or, The particle size of the ferrosilicon is less than 0.038 mm.

7. The processing method according to claim 1, characterized in that The grinding includes grinding by wet grinding, and the weight content of the ore with a particle size of ≤0.074 mm in the target bauxite of the grinding is 80% to 95%.

8. The processing method according to claim 1, characterized in that The magnetic field intensity of the magnetic separation is 0.2T to 1.2T, and the number of magnetic separations is 1 to 3 times.

9. The processing method according to claim 1, characterized in that: The particle size D of the coarse-grained bauxite satisfies: n<D≤10mm; The particle size d of the fine-grained bauxite satisfies: 0 mm < d ≤ n; Among them, the value of n is 0.074mm.

10. The processing method according to claim 9, characterized in that: n is the particle size dividing value between the coarse-grained bauxite and the fine-grained bauxite.

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