Vanadium-titanium magnetite combined grading grinding and separation method

Abstract

The application discloses a vanadium-titanium magnetite combined grading grinding and separation method, which comprises the following steps: grinding the crushing product in a first-stage grinding mill, and then returning the first-stage sand setting to the first-stage grinding mill through a first-stage cyclone grading; performing first-stage weak magnetic separation on the first-stage overflow; feeding the first-stage concentrate into a second-stage cyclone; obtaining second-stage overflow and second-stage sand setting after the second-stage cyclone grading; feeding the second-stage overflow into a fine screen grading, feeding the screen oversize into a concentration grading, feeding the screen undersize into a second-stage weak magnetic separation to obtain second-stage concentrate and second-stage tailings; feeding the third-stage sand setting after dehydration of the concentration grading and the second-stage sand setting into a second-stage grinding mill for grinding, and then feeding the third-stage overflow into the magnetic separation grading together with the third-stage overflow, to obtain third-stage concentrate and third-stage tailings; feeding the third-stage concentrate back to the second-stage cyclone, and feeding the first-stage tailings, the second-stage tailings and the third-stage tailings into a titanium separation process; and outputting the second-stage concentrate as qualified vanadium-titanium iron concentrate or feeding the second-stage concentrate into a next-stage grading grinding and separation system. The method improves the grading efficiency and grinding efficiency of the grading grinding system, and effectively improves the grinding effect.

Description

Technical Field

[0001] This invention relates to the field of vanadium-titanium magnetite beneficiation technology, and in particular to a combined classification and grinding method for vanadium-titanium magnetite. Background Technology

[0002] In mineral processing, grinding is a process that uses the impact and abrasive action of grinding media and the ore itself to fully liberate valuable minerals and gangue, a prerequisite for mineral separation. Moreover, mineral beneficiation is often limited by material particle size; concentrates with excessively coarse particles have higher recovery rates but lower grades, while concentrates with excessively fine particles have higher grades but lower recovery rates. Practice shows that mineral beneficiation operations require a high degree of liberation of the target mineral in the grinding product, along with fewer coarse and fine particles and more easily beneficiated intermediate particles, resulting in a relatively uniform product particle size. In production practice, grinding aims to achieve the required liberation of minerals and meet particle size separation criteria, with mineral liberation being the primary objective.

[0003] Ore particles can be classified into coarse heavy mineral particles, fine heavy mineral particles, coarse light mineral particles, and fine light mineral particles according to their size and density. Currently, vanadium-titanium magnetite classification and grinding systems mainly consist of classification hydrocyclones, high-frequency vibrating fine screens, and mills. The slurry enters the classification hydrocyclones and high-frequency vibrating fine screens. The hydrocyclone underflow and the oversize material from the fine screen are then ground in the mill and returned to the previous stage's classification hydrocyclone, forming a closed-loop classification grinding cycle. In existing technologies, multi-stage grinding and beneficiation processes use a combination of hydrocyclones and fine screens to classify the feed. This method can maximize the removal of coarse tailings in the second-stage grinding process; however, it requires large quantities of magnetic separation equipment and fine screens, consumes a lot of water, and the feed concentration to the fine screen is difficult to control. This wastes mill energy and may also lead to over-grinding, affecting the grinding effect.

[0004] Therefore, there is a need to improve the existing technology for combined classification and grinding methods of vanadium-titanium magnetite. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a combined classification and grinding method for vanadium-titanium magnetite, which improves the grinding concentration by using multi-stage grinding, hydrocyclone classification, magnetic separation, and fine screening and concentration classification, thereby increasing the classification efficiency and grinding efficiency of the classification and grinding system and effectively improving the grinding effect.

[0006] To achieve the above objectives, embodiments of the present invention provide a combined classification and grinding method for vanadium-titanium magnetite, comprising the following steps:

[0007] The crushed vanadium-titanium magnetite product is ground in a first-stage mill, then classified by a first-stage hydrocyclone to obtain a first-stage underflow and a first-stage overflow. The first-stage underflow is returned to the first-stage mill feed.

[0008] After a weak magnetic separation process is performed on an overflow section, the first concentrate and the first tailings are obtained. The first concentrate then enters a second hydrocyclone for classification.

[0009] After the two-stage hydrocyclone classification, two-stage overflow and two-stage underflow are obtained. The two-stage overflow enters the fine screen classification, the oversize enters the concentration classification, and the undersize enters the two-stage weak magnetic separation to obtain the second concentrate and the second tailings.

[0010] After concentration, classification and dewatering, three stages of underflow and three stages of overflow are obtained. The underflow from the third stage and the underflow from the second stage enter the second stage mill for grinding, and then enter the magnetic separation and classification together with the overflow from the third stage. After classification, the third concentrate and the third tailings are obtained.

[0011] The third concentrate is returned to the second-stage hydrocyclone feed, and the first, second, and third tailings are combined and enter the titanium beneficiation process. The second concentrate is produced as qualified vanadium-titanium iron concentrate or enters the next stage classification and grinding system.

[0012] In some implementations, the concentration of the oversize material after concentration and grading is greater than 80%.

[0013] In some implementations, concentration and grading are performed using a slant plate concentration and grading box or a concentration and grading machine.

[0014] In some implementations, fine sieving includes grading using one or more combinations of high-frequency fine sieves, stacked sieves, and Drake sieves.

[0015] In some embodiments, the sieve aperture size is 0.154–0.074 mm.

[0016] In some implementations, the field strength of the magnetic separation stage is equal to or higher than the field strength of the first-stage weak magnetic separation and the second-stage weak magnetic separation.

[0017] In some implementations, the magnetic field strength for the first stage of magnetic separation is controlled at 0.2–0.4 T, the magnetic field strength for the first stage of weak magnetic separation is controlled at 0.2–0.4 T, and the magnetic field strength for the second stage of weak magnetic separation is controlled at 0.15–0.25 T.

[0018] In some implementations, the mineral content with a fineness of -0.074 mm after primary grinding is controlled at 35% to 45% by mass percentage.

[0019] In some implementations, the content of minerals with a fineness of -0.074 mm after two-stage grinding is controlled at 65-75% by mass percentage.

[0020] In some embodiments, the particle size of the vanadium-titanium magnetite ore is ≤12mm, and the TFe content is 26-30% and the TiO2 content is 8-10% by mass percentage.

[0021] The present invention has at least the following beneficial technical effects:

[0022] (1) The fine screen oversize material is concentrated and dehydrated by increasing the concentration of the fine screen oversize material entering the second-stage mill, thereby increasing the grinding concentration and improving the grinding effect.

[0023] (2) The overflow from the concentration and classification is mixed with the discharge from the second-stage mill and then enters the magnetic separation and classification, which reduces the concentration of the discharge from the second-stage mill and is more conducive to magnetic separation and classification.

[0024] (3) After the concentrated and graded sand and the sand from the second-stage hydrocyclone enter the second-stage mill for grinding, they are mixed with the overflow from the concentrated and graded sand for magnetic separation and classification. The magnetically separated concentrate is returned to the second-stage hydrocyclone feed, which reduces the amount of ore returned to the second-stage mill and improves the classification efficiency and grinding efficiency of the classification and grinding system.

[0025] (4) The tailings from magnetic separation and classification are introduced into the titanium beneficiation process in advance, which also reduces the over-grinding and mudding of ilmenite. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart illustrating an embodiment of the vanadium-titanium magnetite combined classification and grinding method provided by the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0029] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0030] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] Based on the working principle of the equipment, it can be observed that the hydrocyclone underflow mainly consists of coarse heavy mineral particles, with a concentration of approximately 70%, while the fine screen overflow mainly consists of coarse light mineral particles, with a concentration of approximately 30%. However, both types of material contain fine heavy and light mineral particles. Returning this material to the mill wastes mill energy and increases the over-grinding of ilmenite. If the fine screen overflow has an excessively low concentration, returning it to the mill negatively impacts the grinding efficiency. Therefore, this invention provides a combined classification and grinding method for vanadium-titanium magnetite, such as... Figure 1 As shown, the specific steps include:

[0032] S1. The crushed vanadium-titanium magnetite product is ground in a first-stage mill, and then classified by a first-stage hydrocyclone to obtain a first-stage underflow and a first-stage overflow. The first-stage underflow is returned to the first-stage mill feed.

[0033] S2. After a weak magnetic separation of the first stage of overflow, the first concentrate and the first tailings are obtained. The first concentrate enters the second stage hydrocyclone for classification.

[0034] S3. After the two-stage hydrocyclone classification, two-stage overflow and two-stage underflow are obtained. The two-stage overflow enters the fine screen classification, the oversize enters the concentration classification, and the undersize enters the two-stage weak magnetic separation to obtain the second concentrate and the second tailings.

[0035] S4. After concentration, classification and dewatering, three-stage underflow and three-stage overflow are obtained. The three-stage underflow and the two-stage underflow enter the two-stage mill for grinding, and then enter the magnetic separation and classification together with the three-stage overflow. After classification, the third concentrate and the third tailings are obtained.

[0036] S5. The third concentrate is returned to the second-stage hydrocyclone feed. The first, second, and third tailings are combined and enter the titanium beneficiation process. The second concentrate is produced as qualified vanadium-titanium iron concentrate or enters the next stage classification and grinding system.

[0037] Furthermore, in S1, the particle size of the vanadium-titanium magnetite ore is ≤12mm, and the TFe content is 26-30% and the TiO2 content is 8-10% by mass percentage. After crushing the vanadium-titanium magnetite ore, it is subjected to a first-stage grinding mill. After the first-stage grinding, the content of minerals with a fineness of -0.074mm is controlled at 35-45%.

[0038] Furthermore, in S2, the strength of a weak magnetic separation magnetic field is controlled between 0.2 and 0.4 T.

[0039] Further, in S3, the second-stage overflow enters a fine screening stage, which includes classification using one or more combinations of a high-frequency fine screen, a stacked screen, and a Derek screen. In some embodiments, the screen aperture size is 0.154–0.074 mm. The oversize material enters a concentration stage, and the undersize material enters a second-stage weak magnetic separation stage to obtain a second concentrate and a second tailings. In some embodiments, the magnetic field strength of the second-stage weak magnetic separation stage is controlled at 0.15–0.25 T.

[0040] Further, in S4, the oversize material on the sieve is concentrated, classified, and dewatered. The concentration of the oversize material after concentration and classification is greater than 80%. The concentration and classification are carried out using an inclined plate concentration and classification box or a concentration and classification machine. The undersize from the third stage and the undersize from the second stage enter the second stage mill for grinding. After the second stage grinding, the content of minerals with a fineness of -0.074mm is controlled at 65-75%. Magnetic separation and classification can be carried out using gravity magnetic pull or other weak magnetic separators with slightly higher field strength. In some embodiments, the magnetic field strength for magnetic separation and classification is controlled at 0.2-0.4T.

[0041] Compared with existing vanadium-titanium magnetite beneficiation processes, the process of this invention has the following advantages: First, the concentration and classification can increase the concentration on the fine screen to about 80%. The concentration of the concentrated and classified sediment is higher than that on the fine screen, and it is then returned to the secondary mill for grinding, which is equivalent to increasing the grinding concentration and improving the grinding effect. Second, the overflow from the concentrated and classified sedimentation is given to the discharge outlet of the secondary mill, which reduces the discharge concentration of the secondary mill and is beneficial to magnetic separation and classification. Third, magnetic separation and classification reduces the amount of ore returned to the secondary mill, improving the classification efficiency and grinding efficiency of the classification and grinding system. Fourth, the tailings from magnetic separation and classification enter the titanium beneficiation process in advance, which also reduces the over-grinding and mudding of ilmenite.

[0042] The present invention will be further explained below with reference to specific embodiments.

[0043] Example 1

[0044] The crushed vanadium-titanium magnetite product is ground in a primary mill at a feed rate of 55 g / t. -1 The grinding concentration is 70%, the grinding time is 5 to 25 minutes, the content of -0.074mm fineness in the first grinding stage is controlled at 40%, and after passing through a hydrocyclone for classification, a stage of underflow and a stage of overflow are obtained. The hydrocyclone classification efficiency is 32%, and the stage of underflow is returned to the first mill feed.

[0045] After a weak magnetic separation is performed on the overflow, the first concentrate and the first tailings are obtained. The magnetic field strength of the weak magnetic separation in the first stage of iron ore beneficiation is controlled at 0.3T. The first concentrate enters the second stage hydrocyclone for classification.

[0046] After classification by the two-stage hydrocyclone, two-stage overflow and two-stage grit are obtained. The two-stage overflow enters the fine screen classification. The screen aperture size of the iron ore fine screen is controlled at 0.125mm, and the fine screen classification efficiency is 35%. The oversize material enters the concentration classification, and the undersize material enters the two-stage weak magnetic separation to obtain the second concentrate and the second tailings. The magnetic field strength of the two-stage weak magnetic separation is controlled at 0.2T.

[0047] The oversize material is concentrated, classified, and dewatered. The concentration of the oversize material after concentration and classification is 80%. After classification, three-stage underflow and three-stage overflow are obtained. The underflow from the third stage and the underflow from the second stage are ground in a two-stage mill and then together with the overflow from the third stage are sent to magnetic separation for classification. The fineness of the second-stage mill is controlled at 70% for -0.074mm content. The magnetic field strength of the magnetic separation is controlled at 0.4T. After classification, the third concentrate and the third tailings are obtained.

[0048] The third concentrate is returned to the second-stage hydrocyclone feed, and the first, second, and third tailings are combined and enter the titanium beneficiation process. The second concentrate is produced as qualified vanadium-titanium iron concentrate or enters the next stage classification and grinding system.

[0049] Using the process of this invention to perform combined classification and grinding of vanadium-titanium magnetite, vanadium-titanium iron concentrate with a TFe grade of over 55% can be obtained.

[0050] Table 1 shows the comparison results of the indicators before and after the modification of the two-stage classification and grinding system of a vanadium-titanium magnetite beneficiation plant in Panzhihua. The data after modification is the operation data of Example 1 using the method of the present invention, and the data before modification is the conventional comparison data.

[0051] Table 1 Comparison of indicators before and after the renovation of the two-stage classifying grinding system in a vanadium-titanium magnetite beneficiation plant in Panzhihua.

[0052]

[0053] As can be seen from the table above, the process of this invention can improve the classification efficiency and grinding efficiency of the classification grinding system, while reducing the over-grinding and mudding of ilmenite, resulting in significant economic and social benefits.

[0054] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0055] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0056] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0057] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for combined classification and grinding of vanadium-titanium magnetite, characterized in that, include: The crushed vanadium-titanium magnetite product is ground in a first-stage mill, and then classified by a first-stage hydrocyclone to obtain a first-stage underflow and a first-stage overflow. The first-stage underflow is returned to the feed mill of the first stage mill. After a weak magnetic separation is performed on an overflow section, the first concentrate and the first tailings are obtained. The first concentrate then enters a second hydrocyclone for classification. After classification by a two-stage hydrocyclone, two-stage overflow and two-stage underflow are obtained. The two-stage overflow enters fine screening for classification, the oversize enters concentration classification, and the undersize enters two-stage weak magnetic separation to obtain the second concentrate and the second tailings. After concentration, classification and dewatering, three stages of underflow and three stages of overflow are obtained. The three stages of underflow and the two stages of underflow enter the two-stage mill for grinding, and then enter the magnetic separation and classification together with the three stages of overflow. After classification, the third concentrate and the third tailings are obtained. The third concentrate is returned to the second-stage hydrocyclone feed, and the first tailings, the second tailings and the third tailings are combined and enter the titanium beneficiation process. The second concentrate is produced as qualified vanadium-titanium iron concentrate or enters the next stage classification and grinding system. The magnetic field strength for magnetic separation is controlled at 0.2–0.4T, the magnetic field strength for the first stage of weak magnetic separation is controlled at 0.2–0.4T, and the magnetic field strength for the second stage of weak magnetic separation is controlled at 0.15–0.25T. By mass percentage, the content of minerals with a fineness of -0.074 mm after primary grinding is controlled at 35%–45%. By mass percentage, the content of minerals with a fineness of -0.074 mm after two-stage grinding is controlled at 65-75%.

2. The method for combined classification and grinding of vanadium-titanium magnetite according to claim 1, characterized in that, The concentration of the oversize material after concentration and classification is greater than 80%.

3. The method for combined classification and grinding of vanadium-titanium magnetite according to claim 1, characterized in that, Concentration and grading are performed using inclined plate concentration and grading boxes or concentration and grading machines.

4. The method for combined classification and grinding of vanadium-titanium magnetite according to claim 1, characterized in that, Fine sieving classification includes grading using one or more combinations of high-frequency fine sieves, stacked sieves, and Derek sieves.

5. The method for combined classification and grinding of vanadium-titanium magnetite according to claim 4, characterized in that, The sieve aperture size is 0.154–0.074 mm.

6. The method for combined classification and grinding of vanadium-titanium magnetite according to claim 1, characterized in that, The field strength of the magnetic separation stage is equal to or higher than the field strength of the first-stage weak magnetic separation and the second-stage weak magnetic separation.

7. The method for combined classification and grinding of vanadium-titanium magnetite according to claim 1, characterized in that, The particle size of the vanadium-titanium magnetite ore is ≤12mm, and the TFe content is 26-30% and the TiO2 content is 8-10% by mass percentage.

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