A method and device for deep recovery of low-grade strong magnetic tailings ilmenite

Abstract

The present invention discloses a method and apparatus for deep recovery of ilmenite from low-grade, strong magnetic tailings. The method involves combining and classifying the first and second stage strong magnetic tailings, which are separated by TiO2 grade; concentrating and desludging the fine-grained material obtained from the combined classification; and combining and enriching the grit obtained from the concentration and desludging operations. Finally, the resulting coarse concentrate is subjected to flotation to produce a ilmenite concentrate. Through this method, the present invention enables efficient and deep recovery of ultrafine ilmenite particles smaller than 0.038 mm from low-grade, strong magnetic tailings with a TiO2 grade of 2.5-7%, yielding a ilmenite concentrate with a TiO2 grade of 46.50% or higher. This effectively addresses a series of issues currently encountered in the prior art, such as low ilmenite recovery rates and high recovery costs from low-grade, strong magnetic tailings.

Description

Technical Field

[0001] The present invention relates to the technical field of ilmenite separation, in particular to a method and device for deep recovery of low-grade strong magnetic tailings ilmenite. Background Art

[0002] Currently, a "two-stage high-intensity magnetic separation + flotation" process is commonly used in China to recover ilmenite from vanadium-titanium magnetite iron ore tailings. However, the overall ilmenite recovery rate is low, at around 50% relative to the iron ore tailings. Analysis has revealed that the primary sources of loss in the titanium beneficiation process are the first and second stage high-intensity magnetic tailings. The first stage high-intensity magnetic tailings are of ultra-low grade (TiO2 grade between 2.5-4%), while the second stage high-intensity magnetic tailings are of low grade (TiO2 grade between 4-7%). Because the particle size distribution of the high-intensity magnetic tailings is more concentrated at the ends and less concentrated in the middle, the intermediate fraction is fully recovered. The head of the two ends has a coarse particle size and very low grade, while the tail has an ultra-fine particle size, severe mudification, but higher grade. Discharging the high-intensity magnetic tailings directly into the tailings pond as part of the total tailings wastes some of the titanium resources in the high-intensity magnetic tailings, particularly the ultra-fine, higher-grade portion. In the Panzhihua region, for example, tens of millions of tons of high-intensity magnetic tailings enter tailings ponds annually. As ore mining progresses deeper, the particle size of useful minerals becomes increasingly finer. Fine grinding is required to obtain qualified iron and titanium concentrates, resulting in an increasing amount of ultrafine ilmenite particles below 0.038mm. Discarding this ilmenite would be a significant waste of resources. Furthermore, the market demand for titanium concentrate is increasing year by year, and the market price of titanium concentrate has been rising, creating a market demand for ultrafine titanium concentrate.

[0003] In view of this, increasing the recovery of ultrafine-grained ilmenite in strong magnetic tailings and filling the gap in effective deep recovery of this type of resources will bring huge economic and social benefits. Summary of the Invention

[0004] The purpose of the present invention is to explore a method for solving the problem of poor enrichment effect of ilmenite in low-grade strong magnetic tailings, especially ultrafine ilmenite with a particle size of less than 0.038 mm, to achieve efficient recovery of ultrafine ilmenite with a particle size of less than 0.038 mm in low-grade strong magnetic tailings, to fill the gap in the deep recovery process of ilmenite in titanium-separated strong magnetic tailings, and to effectively solve a series of problems in the prior art, such as low recovery rate and high recovery cost of ilmenite in low-grade strong magnetic tailings.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for deep recovery of low-grade strong magnetic tailings ilmenite, the method comprising:

[0007] Carry out combined classification operations on the first and second stage strong magnetic tailings divided according to TiO2 grade;

[0008] The fine-grained materials obtained from the combined classification operation are concentrated and desludged separately;

[0009] The sediment obtained from the concentration and desludging operation is subjected to combined enrichment operations respectively;

[0010] The coarse concentrate obtained from the combined enrichment operation is subjected to flotation to obtain titanium concentrate.

[0011] As a further improvement of the present invention, the TiO2 grade of the first-stage strong magnetic tailings is 2.5-4%; the TiO2 grade of the second-stage strong magnetic tailings is 4-7%.

[0012] As a further improvement of the present invention, the combined grading operation includes:

[0013] The first cyclone is used to classify the first-stage strong magnetic tailings and the second-stage strong magnetic tailings respectively, and the strong magnetic tailings with a particle size of ≤0.038 mm are separated.

[0014] As a further improvement of the present invention, the combined grading operation further includes:

[0015] A concentrator classifier is used in combination with a first cyclone to classify the first-stage strong magnetic tailings and the second-stage strong magnetic tailings respectively to separate the strong magnetic tailings with a particle size of ≤0.038 mm.

[0016] As a further improvement of the present invention, a concentrating classifier is used to classify the first stage strong magnetic tailings and the second stage strong magnetic tailings into strong magnetic tailings with a particle size of ≤0.045-0.074 mm at one time;

[0017] The first cyclone is used to perform secondary classification to obtain the strong magnetic tailings with a particle size of ≤0.038 mm from the strong magnetic tailings with a particle size of ≤0.045-0.074 mm obtained by the primary classification.

[0018] As a further improvement of the present invention, the concentration and desludging operation includes:

[0019] The second cyclone is used to remove the strong magnetic tailings with a particle size of less than 0.005 to 0.010 mm.

[0020] As a further improvement of the present invention, the combined enrichment operation includes:

[0021] A strong magnetic machine is used to enrich the two types of sediments respectively to improve the grade of TiO2 in the sediments.

[0022] As a further improvement of the present invention, the combined enrichment operation further comprises:

[0023] Use a strong magnetic machine to carry out primary enrichment of sediment;

[0024] The concentrated tailings obtained after the primary enrichment are subjected to secondary enrichment using a suspended vibrating cone concentrator.

[0025] As a further improvement of the present invention, the secondary enrichment using a suspended cone concentrator includes:

[0026] The suspended vibrating cone concentrator is used to carry out a multi-stage operation combination of roughing, scavenging and concentrating.

[0027] As a further improvement of the present invention, the flotation of the coarse concentrate obtained from the combined enrichment operation includes:

[0028] The two coarse concentrates obtained from the combined enrichment operation are mixed and then subjected to a unified flotation operation.

[0029] The present invention also provides a low-grade strong magnetic tailings ilmenite deep recovery device, the device comprising:

[0030] The grading mechanism is used to carry out combined grading operations on the first stage strong magnetic tailings and the second stage strong magnetic tailings divided according to TiO2 grade;

[0031] Desludging mechanism, used for concentrating and desludging the fine-grained materials obtained from the combined classification operation;

[0032] An enrichment mechanism is used to carry out combined enrichment operations on the sediment obtained from the concentration and desludging operations;

[0033] The flotation mechanism is used to float the coarse concentrate obtained from the combined enrichment operation to obtain titanium concentrate.

[0034] As a further improvement of the present invention, the grading mechanism includes a first cyclone, and the diameter of the sand settling nozzle of the first cyclone is 10-16 mm;

[0035] The desludging mechanism includes a second cyclone, and the diameter of the sand settling nozzle of the second cyclone is 10-14 mm;

[0036] The enrichment mechanism includes a strong magnetic machine.

[0037] As a further improvement of the present invention, the classification mechanism further comprises: a concentration classifier connected to the feed end of the first cyclone;

[0038] The enrichment mechanism further comprises: a suspended vibration cone concentrator connected to the discharge end of the strong magnetic machine.

[0039] Technical effects and advantages of the present invention:

[0040] The present invention provides a method and apparatus for deep recovery of ilmenite from low-grade, strong magnetic tailings. The method and apparatus utilizes a combined classification process for the first and second stage strong magnetic tailings, which are classified according to TiO2 grade; a concentration and desludging process for the fine-grained material obtained from the combined classification process; a combined enrichment process for the sediment obtained from the concentration and desludging process; and flotation of the coarse concentrate obtained from the combined enrichment process to obtain ilmenite concentrate. Through the above-described methods, the present invention enables efficient and deep recovery of ultrafine-grained ilmenite from low-grade, strong magnetic tailings, effectively resolving a series of problems in the prior art, such as low ilmenite recovery rates and high recovery costs, from low-grade, strong magnetic tailings.

[0041] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The figure is a schematic flow chart of the method for deep recovery of low-grade strong magnetic tailings ilmenite of the present invention. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] To achieve the above-mentioned object, the present invention provides a method for recovering ilmenite, particularly ultrafine-grained ilmenite, from low-grade strong magnetic tailings. Based on the TiO2 content in the titanium beneficiation strong magnetic tailings produced by the current production process, the tailings are divided into two types: ultra-low grade (TiO2 grade between 2.5-4%) and low grade (TiO2 grade between 4-7%). These are the first-stage strong magnetic tailings and the second-stage strong magnetic tailings produced by the current titanium beneficiation operation, respectively. The specific process flow is shown in the attached Figure 1 The process includes the following steps: the first and second stage strong magnetic tailings discarded by the current titanium production process are respectively fed into a combined classification operation to obtain two products, coarse and fine particles; the coarse particles are discarded depending on the situation, and the fine particles are fed into a concentration and desludging operation to obtain sand settling and overflow; the sand settling is fed into a combined enrichment operation to obtain two products, coarse concentrate and enriched tailings; the coarse concentrate is fed into flotation to obtain titanium concentrate with a TiO2 grade of ≥46.50%.

[0045] Specifically, the first-stage strong magnetic tailings (the content of tailings with TiO2 grade between 2.5-4% and particle size less than 0.074mm accounts for 50-60% of the total content of the first-stage strong magnetic tailings and the content of tailings with particle size less than 0.038mm accounts for 35-45% of the total content of the first-stage strong magnetic tailings) and the second-stage strong magnetic tailings (the content of tailings with TiO2 grade between 4-7% and particle size less than 0.074mm accounts for 40-50% of the total content of the second-stage strong magnetic tailings and the content of tailings with particle size less than 0.038mm accounts for 20-35% of the total content of the second-stage strong magnetic tailings) discarded by the current titanium dressing production process are respectively fed into the combined grading operation for particle size classification. Among them, the coarse-grained material obtained from the first-stage strong magnetic tailings classification has a low TiO2 grade of ≤2.5%, and the ilmenite therein is mainly poor intergrowth, so it can be discarded as coarse slag. The coarse-grained material obtained from the second-stage strong magnetic tailings classification has a TiO2 grade between 2.5-5.5%, so it can be considered for discarding or further processing separately according to its grade and intergrowth conditions; and the two types of classified fine-grained materials are respectively fed into the cyclone for concentration and desludging operations.

[0046] Specifically, the present invention adopts a combined classification of "inclined plate thickening and grading box (or thickening and grading machine) + cyclone", and optimizes the combined classification particle size of fine-grained materials ≤0.038mm through experiments. Among them, the inclined plate thickening and grading box (or thickening and grading machine) can separate materials with a particle size of ≤0.045~0.074mm through the first-level classification. The main purpose is to classify qualified coarse-grained materials in advance, create a more uniform particle size for the second-level classification of the cyclone, prevent a small number of large-particle coarse-grained materials from clogging the cyclone sand settling nozzle, and ensure the continuous and stable operation of the system; the sand settling nozzle diameter is set to 10-16mm, and the particle size of the fine-grained materials classified by the cyclone is ≤0.038mm. The main purpose of the cyclone is to check and classify qualified fine-grained materials, and at the same time improve the grade of fine-grained materials. According to the test results, the grade of fine-grained materials is 2-4 percentage points higher than that of the combined classification raw materials. Of course, the first-level classification operation can sometimes be cancelled according to the uniformity of the strong magnetic tailings.

[0047] Furthermore, the present invention sets a cyclone to concentrate and desludging the fine-grained tailings obtained after combined classification to obtain high-quality sand, and discards the overflow as sludge. Specifically, a cyclone is used to carry out the concentration and desludging operation of fine-grained materials, and the diameter of the sand nozzle is set to 10-14mm. At this time, the cyclone can concentrate and desludify extremely fine materials with a particle size of <0.005~0.010mm. The main purpose is to ensure that the cyclone sand concentration is higher, the mud content is less, and the sand grade can be moderately improved. According to the test results, the sand concentration is increased by 10 to 20 percentage points compared with the concentrated desludging raw material, and the content of ore mud below 0.010mm in the sand is reduced by 15-35 percentage points compared with the concentrated desludging raw material. The sand grade is increased by 0.5-1.5 percentage points compared with the concentrated desludging raw material.

[0048] Furthermore, the cyclone sedimentation is combined and enriched separately to obtain a first-stage coarse concentrate, a second-stage coarse concentrate, and a first-stage enriched tailings and a second-stage enriched tailings; wherein, the first-stage coarse concentrate and the second-stage coarse concentrate are mixed or separately fed into a flotation operation for further enrichment into a titanium concentrate with a TiO2 grade of ≥46.50%. The present invention fully utilizes the advantages of the high tailings discarding rate of the strong magnetic machine, the high enrichment ratio of the suspended vibration cone concentrator, and the good selective enrichment effect; the former is conducive to improving the TiO2 grade, and the latter helps to improve the TiO2 recovery rate. As a result, the enriched concentrate using the combination of "ZH strong magnetic machine (or SLon strong magnetic machine) + suspended vibration cone concentrator" has the characteristics of high grade and excellent particle size, ultimately creating high-quality and high-grade raw materials for the flotation process, effectively reducing flotation reagent consumption and improving flotation recovery rate. Specifically, flotation can be a single flotation machine, a flotation column, or a combination of a column and a machine. The primary enrichment of the ZH strong magnetic machine (or SLon strong magnetic machine) is a "one roughing and one fine" or "one roughing and two fines" process. The rougher tailings obtained after the primary enrichment are directly discarded due to the low TiO2 grade. The fine tailings are further enriched by the suspended vibration cone concentrator separately or after mixing according to the TiO2 grade to improve the recovery rate of the combined enrichment operation. The secondary enrichment concentrate can be directly used as the total concentrate to participate in the subsequent flotation operation, or it can be returned to the strong magnetic process for re-selection. The gravity separation of the suspended vibration cone concentrator can be a multi-stage operation combination of roughing, scavenging and concentrating of a single gravity separation equipment. Of course, sometimes the gravity separation operation of the suspended vibration cone concentrator can be cancelled according to the TiO2 grade of the strong magnetic tailings obtained after enrichment by the ZH strong magnetic machine (or SLon strong magnetic machine).

[0049] Furthermore, because the incoming grade of the strong magnetic tailings varies greatly and the particle size also has certain differences, in order to improve the classification effect, the first stage strong magnetic tailings and the second stage strong magnetic tailings are respectively subjected to combined classification, concentration and desludging, so that the sediment particle size obtained by concentration and desludging is similar, and then different operating parameters can be used when performing combined enrichment operations respectively, so that the grade of the combined enriched concentrate is also similar, so that the grade and particle size of the floating ore can be close, and then the ultrafine particle size titanium concentrate can be obtained by unified flotation after mixing, further reducing the reagent consumption and construction investment, and achieving the purpose of efficient and low-cost recovery. Of course, it is easy for those skilled in the art to think that the high-grade recovery of titanium concentrate can also be achieved by flotation of the two enriched coarse concentrates separately. Without departing from the concept of the invention, only changing the flotation operation mode should fall within the scope of protection of the present invention.

[0050] Once operational, this process will revitalize the hundreds of millions of tons of highly magnetic tailings in the Panzhihua region, generating tens of billions of yuan in annual economic benefits. Furthermore, this process will pioneer the deep recovery of ilmenite from highly magnetic tailings, setting a significant precedent for deep recovery of ilmenite from highly magnetic tailings nationwide and even globally.

[0051] In summary, the present invention provides a method for deep recovery of low-grade strong magnetic tailings ilmenite, based on the properties of the strong magnetic tailings ore discarded by the current production process, using combined classification to discard coarse-grained materials, and fine-grained materials to obtain high-quality sedimentation through cyclone concentration and desludging. The sedimentation adopts a "ZH strong magnetic machine (or SLon strong magnetic machine) + suspended cone concentrator" to carry out ilmenite combined enrichment, which can improve the grade of cyclone concentration and desludging sedimentation with a TiO2 grade of 5%-8% to more than 16%, and simultaneously the TiO2 recovery rate can reach more than 60%, so that the TiO2 grade of the first and second stage coarse concentrates meets the flotation requirements, and obtains a titanium concentrate with a TiO2 grade of ≥46.50% through flotation. It can be seen that the present invention achieves the deep recovery of ilmenite in strong magnetic tailings with a TiO2 grade of 2.5-7%, particularly ultra-fine ilmenite with a particle size of 0.038 mm or less.

[0052] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for deep recovery of low-grade strong magnetic tailings ilmenite, characterized in that: The method comprises: Carry out combined classification operations on the first and second stage strong magnetic tailings divided according to TiO2 grade; The fine-grained materials obtained from the combined classification operation are concentrated and desludged separately; The sediment obtained from the concentration and desludging operation is subjected to combined enrichment operations respectively; The coarse concentrate obtained from the combined enrichment operation is subjected to flotation to obtain titanium concentrate; The combined grading operation includes: Using a concentrating classifier to classify the first-stage strong magnetic tailings and the second-stage strong magnetic tailings into strong magnetic tailings with a particle size of ≤0.074 mm at one time; Using the first cyclone to perform secondary classification, the strong magnetic tailings with a particle size of ≤0.038 mm are obtained from the strong magnetic tailings with a particle size of ≤0.074 mm obtained by the primary classification; The flotation of the coarse concentrate obtained from the combined enrichment operation comprises: The two coarse concentrates obtained from the combined enrichment operation are mixed and then subjected to a unified flotation operation.

2. The low-grade strong magnetic tailings ilmenite depth recovery method according to claim 1, wherein The TiO2 grade of the first-stage strong magnetic tailings is 2.5-4%; the TiO2 grade of the second-stage strong magnetic tailings is 4-7%.

3. The low-grade strong magnetic tailings ilmenite depth recovery method according to claim 1, wherein The concentration and desludging operation includes: The second cyclone is used to remove the strong magnetic tailings with a particle size of less than 0.010 mm.

4. The low-grade strong magnetic tailings ilmenite depth recovery method according to claim 1, wherein The combined enrichment operation includes: A strong magnetic machine is used to enrich the two types of sediments respectively to improve the grade of TiO2 in the sediments.

5. The low-grade strong magnetic tailings ilmenite depth recovery method according to claim 4, wherein The combined enrichment operation further comprises: Use a strong magnetic machine to carry out primary enrichment of sediment; The concentrated tailings obtained after the primary enrichment are subjected to secondary enrichment using a suspended vibrating cone concentrator.

6. The low-grade strong magnetic tailings ilmenite depth recovery method according to claim 5, wherein The secondary enrichment using the suspended cone concentrator includes: The suspended vibrating cone concentrator is used to carry out a multi-stage operation combination of roughing, scavenging and concentrating.

7. A recovery device for the method for deep recovery of low-grade strong magnetic tailings ilmenite according to any one of claims 1 to 6, characterized in that: The device comprises: The grading mechanism is used to carry out combined grading operations on the first stage strong magnetic tailings and the second stage strong magnetic tailings divided according to TiO2 grade; Desludging mechanism, used for concentrating and desludging the fine-grained materials obtained from the combined classification operation; An enrichment mechanism is used to carry out combined enrichment operations on the sediment obtained from the concentration and desludging operations; Flotation mechanism, used to float the coarse concentrate obtained from the combined enrichment operation to obtain titanium concentrate; The grading mechanism includes a first cyclone, wherein the diameter of the sand settling nozzle of the first cyclone is 10-16 mm; The desludging mechanism includes a second cyclone, and the diameter of the sand settling nozzle of the second cyclone is 10-14 mm; The enrichment mechanism includes a strong magnetic machine.

8. The low-grade strong magnetic tailings ilmenite deep recovery device according to claim 7 is characterized in that: The classification mechanism further comprises: a concentrating classifier connected to the feed end of the first cyclone; The enrichment mechanism further comprises: a suspended vibration cone concentrator connected to the discharge end of the strong magnetic machine.

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