An efficient enrichment method for low-grade fluorite ore

Abstract

The present invention provides a method for efficient enrichment of low-grade fluorite ore, comprising the following steps: performing primary crushing on the original ore sample to obtain a crushed product; classifying the crushed product to obtain a coarse-grained product and a fine-grained product; pre-concentrating and discarding the tailings of the coarse-grained product by using an XRT intelligent separator to obtain XRT pre-concentrated rough concentrate; crushing the XRT pre-concentrated rough concentrate and mixing it with the fine-grained product obtained by crushing and screening to obtain a mixed product; screening and classifying the mixed product into several particle-size products; respectively performing heavy liquid separation on each particle-size product to obtain heavy minerals and light minerals; after washing and drying the heavy minerals, obtaining fluorite concentrate; after washing and drying the light minerals, obtaining tailings products. The method of the present invention can achieve efficient enrichment of low-grade fluorite ore. The CaF2 content of the fluorite concentrate is greater than 90%, and the recovery rate is greater than 85%. The process flow of fluorite beneficiation is simplified, and the separation accuracy of coarse-grained fluorite ore is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorite beneficiation, and particularly to a method for efficiently enriching low-grade fluorite ore. Background Art

[0002] Fluorite is the main raw material for industrial fluorine products and is widely used in industrial fields such as metallurgy, chemical industry, optics, and semiconductor manufacturing. It also has great application potential in fields such as new energy, atomic energy industry, and aerospace. With the gradual depletion of easily beneficiated fluorite ore, the efficient utilization of low-grade fluorite resources (the original ore CaF2 is less than 30%) has received increasing attention. According to different gangue minerals, fluorite resources can be mainly divided into four types: quartz type, calcite type, barite type, and multi-metal ore associated type. Practice has shown that flotation is the main beneficiation method for fluorite ore and can process various types of fluorite resources. At the same time, there are still some technical problems in fluorite flotation: for example, the efficient separation of fluorite and calcite has not been completely solved; the flotation process flow is lengthy, usually requiring regrinding, and the number of cleaning operations is often more than six times; as the feed grade gradually decreases, the production cost of the flotation process continues to increase, etc.

[0003] In order to better process low-grade fluorite resources, many studies have been carried out in the aspects of coarse-grained optoelectronic separation and heavy medium separation in the prior art. For example, the utility model patent with the patent authorization announcement number CN213700011U and the authorization announcement date of July 16, 2021, discloses a dry pre-selection system for low-grade fluorite ore. The fluorite pre-selection process disclosed in this utility model patent is as follows: the original ore is crushed to -40 mm by a jaw crusher, and a product with a particle size of 10 - 40 mm is obtained through a double-deck vibrating screen. This particle size product is fed into an XRT intelligent ore separator, and the waste rock is selected and thrown into the waste rock bin, thereby realizing pre-selection and tail rejection. For a low-grade fluorite ore with a CaF 2 content of about 20%, the grade of the original ore can be increased by about 10% through the above process, and the operation recovery rate is greater than 90%. Analyzing the separation indexes, it can be seen that this process can only achieve the effect of pre-selection and tail rejection, and subsequent processes such as flotation are still required to obtain qualified fluorite concentrate products.

[0004] For example, patent CN 106583029 B discloses a fluorite ore gravity separation process and a fluorite waste rejection gravity separation process. This process includes: two-stage crushing and classification, two-stage screening and cleaning, and two-stage heavy medium separation. The above technology can increase the CaF 2 content of low-grade fluorite ore from less than 30% to 40 - 50%. The main purpose is to obtain an enriched fluorite raw material for flotation production through waste rejection, and it is also impossible to obtain qualified fluorite concentrate products at one time, and the separation accuracy needs to be further improved. Summary of the Invention

[0005] The present invention provides a method for efficient enrichment of low-grade fluorite ore, which can achieve efficient enrichment of low-grade fluorite ore (with CaF2 content less than 20%). The CaF2 content of the fluorite concentrate is greater than 90%, and the recovery rate is greater than 85%. The process flow of fluorite beneficiation is simplified, and the separation accuracy of coarse-grained fluorite ore is greatly improved.

[0006] The technical solution of the present invention is realized as follows: A method for efficient enrichment of low-grade fluorite ore includes the following steps:

[0007] a: The original ore sample is subjected to primary crushing using a jaw crusher to obtain a crushed product;

[0008] b: The primary crushed product is screened and classified to obtain a coarse-grained product and a fine-grained product;

[0009] c: The coarse-grained product is pre-selected and tailings are discarded using an XRT intelligent separator to obtain XRT pre-selected rough concentrate;

[0010] d: The XRT pre-selected rough concentrate is crushed into a product of qualified particle size and mixed with the fine-grained product obtained from the primary crushing and screening to obtain a mixed product;

[0011] e: The mixed product is screened and classified into several particle size products;

[0012] f: Each particle size product in step e is separately subjected to heavy liquid separation to obtain heavy minerals and light minerals;

[0013] g: After the heavy minerals are washed and dried, fluorite concentrate is obtained; after the light minerals are washed and dried, tailings products are obtained.

[0014] Further, in step a, the crushed product is a -80mm particle size product.

[0015] Further, in step b, the coarse-grained product is a 10 - 80mm particle size product, and the fine-grained product is a -10mm particle size product 1.

[0016] Further, in step c, the XRT intelligent separator is used to pre-discard metal gangue minerals with relative atomic weight greater than calcium;

[0017] Further, in step d, the product of qualified particle size is a -10mm particle size product 2;

[0018] Further, in step e, the classification particle size of the screening and classification is any value from 0.3 to 10mm, and several particle sizes are 2 to 5 particle sizes.

[0019] Further, in step f, the heavy liquid is prepared from methylene iodide and 2-bromonaphthalene, and the density of the heavy liquid is 2.5g / cm 3 ~3.0g / cm 3 .

[0020] Further, in step g, the cleaning method is as follows: first, clean with absolute ethanol, and then clean with clear water. All the cleaning liquids are combined, filtered, extracted, and then recycled.

[0021] Advantages of the present invention:

[0022] The method of the present invention is directed to low-grade fluorite ore. By using an XRT intelligent separator to pre-reject metal gangue minerals with a relatively large specific gravity in advance, and then through classification - heavy medium separation, fluorite concentrate products with a CaF 2 content greater than 90% and a recovery rate greater than 85% can be obtained. Compared with the prior art, not only the separation process flow is greatly simplified, but also qualified fluorite concentrate products can be directly obtained without further separation by processes such as flotation. This method has the advantages of simple process flow and high separation accuracy. The low-grade fluorite ore applicable to the present invention mainly consists of minerals such as fluorite, quartz, and calcite. Among them, the fluorite mineral content is 10 - 40%, the quartz content is 30 - 60%, the calcite content is 5 - 30%, and the content of other gangue minerals is less than 15%. In terms of the embedded particle size, the main minerals such as fluorite, quartz, and calcite have a particle size above 0.2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 It is the process flow diagram of a high-efficiency enrichment method for low-grade fluorite ore of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] As Figure 1 shown, a high-efficiency enrichment method for low-grade fluorite ore includes the following steps:

[0027] a: The original ore sample is subjected to primary crushing by a jaw crusher to obtain a crushed product;

[0028] b: Screen and classify a section of broken products to obtain coarse-grained products and fine-grained products;

[0029] c: Use an XRT intelligent separator to pre-concentrate and discard tailings from the coarse-grained products to obtain XRT pre-concentrated rough concentrate;

[0030] d: Use a jaw crusher to crush the XRT pre-concentrated rough concentrate into products of qualified particle size, and mix them with the fine-grained products obtained from the first-stage crushing and screening;

[0031] e: Screen and classify the mixed products into several particle size products;

[0032] f: Perform heavy liquid separation on each particle size product to obtain heavy minerals and light minerals of each particle size;

[0033] g: Wash the heavy minerals and light minerals of each particle size. After washing, dry each product. The heavy minerals are fluorite concentrate, and the light minerals are tailings products.

[0034] Examples of the enrichment of low-grade fluorite ore of the present invention are as follows:

[0035] Example 1

[0036] The fluorite ore sample of this example was collected from a fluorite mine in Hunan. The main chemical components of the raw ore are: CaF 2 about 19.85%, SiO 2 57.30%, CaCO 3 9.85%, Fe 2 O 3 5.24%, MnO 3.47%. The fluorite enrichment process flow of this example is as shown in the appendix Figure 1 The raw ore is crushed to -80mm in one stage by a jaw crusher, and the -80mm crushed products are screened into 10-80mm coarse-grained products and -10mm fine-grained products 1. Use an XRT intelligent separator to pre-concentrate the 10-80mm coarse-grained products, discard metal gangue minerals such as iron and manganese, and obtain XRT pre-concentrated rough concentrate. Use a jaw crusher to crush the XRT pre-concentrated rough concentrate to -10mm to obtain -10mm particle size products 2. Mix the -10mm particle size products 1 and -10mm particle size products 2 to obtain -10mm particle size products 3.

[0037] Screen and classify the -10mm particle size products 3 into five particle sizes: -0.3mm, 0.3-2mm, 2-3mm, 3-5mm, and 5-10mm. The -0.3mm is directly used as tailings products.

[0038] Perform heavy liquid separation on the 0.3-2mm particle size crushed products. The heavy liquid is diiodomethane (density 3.2 g / cm 3(about) and 2-bromonaphthalene (with a density of 1.6 g / cm 3 (about), the same hereinafter), the density of the heavy liquid is 2.85 g / cm 3 , and 0.3-2 mm heavy minerals and 0.3-2 mm light minerals are obtained respectively. The 0.3-2 mm heavy minerals and 0.3-2 mm light minerals are washed with absolute ethanol and then with clean water. All the washing liquids are combined, filtered, extracted and recycled.

[0039] The crushed products of the 2-3 mm particle size are separated by heavy liquid with a density of 2.85 g / cm 3 , and 2-3 mm heavy minerals and 2-3 mm light minerals are obtained respectively. The 2-3 mm heavy minerals and 2-3 mm light minerals are washed with absolute ethanol and then with clean water. All the washing liquids are combined, filtered, extracted and recycled.

[0040] The crushed products of the 3-5 mm particle size are separated by heavy liquid with a density of 2.85 g / cm 3 , and 3-5 mm heavy minerals and 3-5 mm light minerals are obtained respectively. The 3-5 mm heavy minerals and 3-5 mm light minerals are washed with absolute ethanol and then with clean water. All the washing liquids are combined, filtered, extracted and recycled.

[0041] The crushed products of the 5-10 mm particle size are separated by heavy liquid with a density of 2.85 g / cm 3 , and 5-10 mm heavy minerals and 5-10 mm light minerals are obtained respectively. The 5-10 mm heavy minerals and 5-10 mm light minerals are washed with absolute ethanol and then with clean water. All the washing liquids are combined, filtered, extracted and recycled.

[0042] The heavy minerals of the above-mentioned particle sizes are fluorite concentrate, and the light minerals are tailings. The fluorite separation indexes of this example are shown in Table 1.

[0043] Table 1 Fluorite separation indexes of Example 1 / %

[0044]

[0045]

[0046] The yield of the total fluorite concentrate (the fluorite concentrates of each particle size are combined) is 18.95%, the grade of CaF 2 is 91.22%, and the recovery rate of CaF 2 is 87.13%.

[0047] Example 2

[0048] Example 2 is basically the same as Example 1, except that the selected raw materials are collected from a fluorite mine in Yunnan. The main chemical components of the raw ore are: CaF 2 about 18.02%, SiO 2 55.70%, CaCO 3 15.25%, Fe 2 O 3 3.11%, Sb 2 O 3 4.40%. The density of the heavy liquid used for the gravity separation of each particle size product is 2.95 g / cm 3 .

[0049] Table 2 Separation Indexes of Fluorite in Example 2 / %

[0050] Product Name Yield <![CDATA[CaF 2 grade]]> <![CDATA[CaF 2 Recovery rate]]> 5-10mm fluorite concentrate 7.03 90.05 34.99 3-5mm fluorite concentrate 5.14 90.77 25.79 2-3mm fluorite concentrate 2.76 91.03 13.89 0.3-2mm fluorite concentrate 2.17 91.69 11.00 5-10mm tailings 39.22 0.97 2.10 3-5mm tailings 10.57 1.87 1.09 2-3mm tailings 4.11 2.59 0.59 0.3-2mm tailings 3.78 5.23 1.09 XRT pre-selection tailings 15.32 3.57 3.02 -0.3mm products 9.90 11.78 6.44 Ore 100.00 18.09 100.00

[0051] The yield of the total fluorite concentrate (the combined fluorite concentrates of each particle size) is 17.10%, the grade of CaF 2 is 90.63%, and the recovery rate of CaF 2 is 85.66%.

[0052] By analyzing Table 1 and Table 2, it can be seen that an efficient enrichment method for low-grade fluorite ore proposed by the present invention can achieve the efficient enrichment of low-grade fluorite ore (the content of CaF 2 is less than 20%). The content of CaF in the fluorite concentrate 2 is greater than 90%, and the recovery rate is greater than 85%. Compared with the existing technical methods, not only the separation process flow of this method is greatly simplified, but also qualified fluorite concentrate products can be directly obtained without further separation by processes such as flotation. This method has the advantages of simple process flow and high separation accuracy.

[0053] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An efficient enrichment method for low-grade fluorite ore, characterized in that: It includes the following steps: a: The original ore sample is subjected to primary crushing using a jaw crusher to obtain a crushed product; b: The primary crushed product is screened and classified to obtain a coarse-grained product and a fine-grained product; c: The coarse-grained product is pre-selected and tailings are discarded using an XRT intelligent separator to obtain XRT pre-selected rough concentrate; d: The XRT pre-selected rough concentrate is crushed into a product of qualified particle size and mixed with the fine-grained product obtained from the primary crushing and screening to obtain a mixed product; e: The mixed product is screened and classified into several particle size products; f: Each particle size product in step e is separately subjected to heavy liquid separation to obtain heavy minerals and light minerals; g: After the heavy minerals are washed and dried, fluorite concentrate is obtained. The CaF content of the fluorite concentrate is greater than 90%, and the recovery rate is greater than 85%. After the light minerals are washed and dried, tailings products are obtained; 2 The content is greater than 90%, and the recovery rate is greater than 85%. After the light minerals are washed and dried, tailings products are obtained; In step c, the XRT intelligent separator is used to pre-discard metal gangue minerals with a relative atomic mass greater than calcium; In the original ore sample, the fluorite mineral content is 10 - 40%, the quartz content is 30 - 60%, the calcite content is 5 - 30%, and the content of other gangue minerals is less than 15%. In terms of the embedded particle size, the particle sizes of fluorite, quartz, and calcite are above 0.2 mm.

2. The efficient enrichment method for low-grade fluorite ore according to claim 1, characterized in that: The crushed product in step a is a product with a particle size of -80 mm.

3. The efficient enrichment method for low-grade fluorite ore according to claim 1, characterized in that: The coarse-grained product in step b is a product with a particle size of 10 - 80 mm, and the fine-grained product is a product with a particle size of -10 mm.

4. The efficient enrichment method for low-grade fluorite ore according to claim 1, characterized in that: In step d, the product of qualified particle size is a product with a particle size of -10 mm.

5. The efficient enrichment method for low-grade fluorite ore according to claim 1, characterized in that: In step e, the classification particle size for screening and classification is any value from 0.3 to 10 mm, and the number of particle sizes is 2 to 5.

6. The efficient enrichment method for low-grade fluorite ore according to claim 1, characterized in that: In step f, the heavy liquid is prepared from methylene iodide and 2-bromonaphthalene, and the density of the heavy liquid is 2.5 g / cm 3 ~3.0 g / cm 3 .

7. The efficient enrichment method for low-grade fluorite ore according to claim 1, characterized in that: In step g, the cleaning method is: first clean with anhydrous ethanol, and then clean with water. All cleaning liquids are combined, filtered, extracted, and then recycled.

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