Method for pre-concentrating iron concentrate and fluorite concentrate from iron and calcium fluoride associated ore

Abstract

The present invention discloses a method for pre-enriching iron concentrate and fluorite concentrate from iron and calcium fluoride associated ores, comprising the following steps: 1) successively performing coarse crushing, medium crushing, and screening on the iron and calcium fluoride associated ores to obtain fine-grained products and medium-grained products; 2) processing the medium-grained products to obtain dry-selection iron rough tailings and dry-selection iron tailings; 3) processing the fine-grained products to obtain iron concentrate; 4) combining and processing the dry-selection iron rough tailings and dry-selection iron tailings to obtain dry-selection fluorite rough concentrate; performing fine crushing and screening on the dry-selection fluorite rough concentrate to obtain fluorite fine-grained products; 5) processing the fluorite fine-grained products to obtain fluorite concentrate. The method of the present invention can pre-enrich iron concentrate and fluorite concentrate from the associated ores, and can take into account the grades and recovery rates of both the iron concentrate and the fluorite concentrate.

Description

Technical Field

[0001] The present invention relates to a method for pre - enrichment of iron and calcium fluoride associated ores, and particularly to a method for pre - enriching iron concentrate and fluorite concentrate from iron and calcium fluoride associated ores. Background Art

[0002] Fluorite is also known as fluorspar. It is a relatively common mineral in nature and can co - exist with many other minerals. Its main component is calcium fluoride (CaF2).

[0003] Iron ore and fluorite are important mineral resources. Bayan Obo ore deposit is a world - famous multi - metal super - large deposit of iron, rare earth, niobium, etc. In addition, a large amount of fluorite resources are co - associated in the deposit. With the continuous mining of the ore body, the ore body is becoming more depleted, the amount of surrounding rock mined and stripped increases, and the mining cost increases. In addition, due to the complex geological origin of Bayan Obo, the "iron - dominated" mining plan causes a large amount of waste of co - associated fluorite resources during the stripping of the surrounding rock. With the continuous in - depth study of the deposit resources, the comprehensive utilization of fluorite has received attention. Therefore, through the pre - enrichment method, the "threshold" for the utilization of iron and fluorite ores is reduced, that is, the lower - grade co - associated ores are utilized. And it is very necessary to obtain high - grade iron concentrate and fluorite concentrate while improving the iron recovery rate and fluorite recovery rate.

[0004] CN104815736A discloses a pre - selection process for magnetite - containing surrounding rock, including obtaining a first - stage dry pre - selection rough concentrate, and the first - stage dry pre - selection tailings thrown out are used as concrete aggregates; then through fine crushing and second - stage dry pre - selection, a second - stage dry pre - selection rough concentrate is obtained, and the second - stage dry pre - selection tailings thrown out are also used as concrete aggregates; then through high - pressure roll grinding - wet coarse - grain pre - selection, a wet coarse - grain pre - selection concentrate is obtained. This patent document deals with magnetite - containing surrounding rock that contains almost no CaF2.

[0005] CN113426688A discloses a beneficiation process for high - sulfur composite iron ore and its pre - selection production system, using weak magnetic dry separation to recover magnetite from the raw ore, and then the sulfur - containing iron ore dry - selected by an intelligent dry - separator is combined with the weak magnetic concentrate of the weak magnetic dry - separator and enters the fine - crushing buffer ore bin.

[0006] CN113941442A discloses a beneficiation method for recovering extremely low - grade iron and fluorite resources in iron - containing surrounding rock, including the following steps: 1) raw ore crushing and dry magnetic separation pre - selection and rejection operation, 2) high - pressure roll grinding - wet magnetic separation pre - operation for dry - separation concentrate, 3) stage grinding - stage wet magnetic separation operation for wet magnetic separation pre - selection concentrate, 4) fluorite recovery flotation operation for iron - selected tailings. The iron recovery rate of the iron concentrate and the CaF2 recovery rate of the fluorite concentrate obtained in this patent document still need to be improved. Summary of the Invention

[0007] An object of the present invention is to provide a method for pre-enriching iron concentrate and fluorite concentrate from iron and calcium fluoride associated ores. The method of the present invention improves the iron recovery rate and the CaF₂ recovery rate while taking into account the grades of iron concentrate and fluorite concentrate. The object of the present invention is achieved by the following technical solutions.

[0008] The present invention provides a method for pre-enriching iron concentrate and fluorite concentrate from iron and calcium fluoride associated ores, comprising the following steps:

[0009] 1) Coarsely crush and then medium-crush the iron and calcium fluoride associated ores in sequence to obtain medium-crushed products; screen the medium-crushed products to obtain fine-grained products and medium-grained products;

[0010] Among them, the particle size of the fine-grained products is less than 12 mm, and the particle size of the medium-grained products is greater than or equal to 12 mm and less than 60 mm;

[0011] 2) Dry-preselect the medium-grained products under a drum surface magnetic field intensity of 260 - 350 mT to obtain dry-selected iron rough concentrate and dry-selected iron rough tailings; finely crush the dry-selected iron rough concentrate to obtain finely crushed products; screen the finely crushed products to obtain a first iron fine-grained product with a particle size less than 12 mm and an iron coarse-grained product with a particle size greater than or equal to 12 mm; dry-preselect the iron coarse-grained products under a drum surface magnetic field intensity of 260 - 350 mT to obtain dry-selected iron concentrate and dry-selected iron tailings; return the dry-selected iron concentrate to the fine-crushing step for fine-crushing and screening until the particle size of the screened products is less than 12 mm to obtain a second iron fine-grained product;

[0012] 3) Combine the fine-grained products, the first iron fine-grained product, and the second iron fine-grained product, and perform ball milling, magnetic separation, and reverse flotation in sequence to obtain iron concentrate;

[0013] 4) Combine the dry-selected iron rough tailings and the dry-selected iron tailings to obtain combined iron tailings; dry-preselect the combined iron tailings through an optoelectronic separator to obtain dry-selected fluorite rough concentrate and dry-selected fluorite rough tailings; finely crush and screen the dry-selected fluorite rough concentrate to obtain a fluorite fine-grained product with a particle size less than 12 mm and a fluorite coarse-grained product with a particle size greater than or equal to 12 mm; dry-preselect the fluorite coarse-grained product again through an optoelectronic separator to obtain dry-selected fluorite concentrate and dry-selected fluorite tailings; return the dry-selected fluorite concentrate to the fine-crushing step for fine-crushing and screening until the particle size of the screened products is less than 12 mm to obtain a second fluorite fine-grained product;

[0014] 5) Combine the fluorite fine-grained products and the second fluorite fine-grained product to obtain combined products, and perform ball milling and flotation on the combined products in sequence to obtain fluorite concentrate.

[0015] According to the method of the present invention, preferably, in the iron and calcium fluoride associated ore, the total iron grade is greater than or equal to 13.5 wt%, and the CaF2 content is greater than or equal to 12 wt%.

[0016] According to the method of the present invention, preferably, in step 1), a gyratory crusher or a jaw crusher is used for coarse crushing; a cone crusher is used for medium crushing.

[0017] According to the method of the present invention, preferably, in step 2), a magnetic pulley is used for dry pre-selection under a drum surface magnetic field intensity of 260 - 350 mT.

[0018] According to the method of the present invention, preferably, in steps 2) and 4), a single-layer circular vibrating screen is used for screening.

[0019] According to the method of the present invention, preferably, in step 3), the fine-grained product, the first iron fine-grained product, and the second iron fine-grained product are combined to obtain a combined fine-grained product; the combined fine-grained product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 88 - 92% to obtain a grinding product; the grinding product is subjected to magnetic separation twice under a magnetic separation field intensity of 200 - 220 mT to obtain a crude iron concentrate; the crude iron concentrate is ball-milled again until the content of particles with a particle size less than 0.045 mm accounts for 70 - 80% to obtain a re-ground product; the re-ground product is subjected to one-time reverse flotation to obtain an iron concentrate; wherein, the pulp concentration of the reverse flotation is 36 - 40 wt%, the temperature is 30 - 35 °C, the pH is 8 - 9, the collector is a modified product of sodium oleate, and the inhibitor is water glass; based on the weight of the re-ground product, the dosages of the collector and the inhibitor are 0.5 - 1.0 kg / t and 0.8 - 1.2 kg / t respectively.

[0020] According to the method of the present invention, preferably, the optoelectronic separator is an XRT intelligent optoelectronic separator.

[0021] According to the method of the present invention, preferably, in step 5), the fluorite fine-grained product and the second fluorite fine-grained product are combined to obtain a combined product, and the combined product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 90 - 95% to obtain a ground fluorite product;

[0022] The ground fluorite product is subjected to one-time rough selection and more than two times of fine selection to obtain a crude fluorite concentrate; wherein, the pulp concentration of the one-time rough selection is 35 - 40 wt%, the pulp concentration of the more than two times of fine selection is 25 - 28%, the flotation temperature is 30 - 35 °C, and the pH is 8 - 9; the inhibitor used in the one-time rough selection and more than two times of fine selection is water glass, and the collector used in the one-time rough selection is a modified product of sodium oleate; based on the weight of the ground fluorite product, the dosage of the inhibitor in each flotation is 2.0 - 3.5 kg / t; in the one-time rough selection, the dosage of the collector is 0 - 2.0 kg / t;

[0023] The crude fluorite concentrate is reground until the content of particles with a particle size less than 0.028 mm accounts for 90-95% to obtain a reground fluorite product; the reground fluorite product is subjected to multiple selections to obtain a fluorite concentrate; wherein, the pulp concentration for multiple selections is 15-35 wt%, the temperature is 30-40 °C, the pH is 4.5-6.0, the inhibitors used are acid water glass and tannic acid, the collector is phthalic acid, and the foaming agent is No. 2 oil; based on the weight of the reground fluorite product, in each selection, the dosages of acid water glass, tannic acid, phthalic acid, and No. 2 oil are 0.2-0.5 kg / t, 0.1-0.6 kg / t, 0.3-1.0 kg / t, and 0.1-0.2 kg / t respectively; the acid water glass is formed from sulfuric acid and water glass with a mass ratio of 2.8-3.2:1.

[0024] According to the method of the present invention, preferably, it further includes: combining the dry-selected fluorite tailings and the dry-selected crude fluorite tailings into dry-selected final tailings.

[0025] According to the method of the present invention, preferably, the iron recovery rate in the obtained iron concentrate is greater than or equal to 60%, and the CaF2 recovery rate in the obtained fluorite concentrate is greater than or equal to 50%.

[0026] The method of the present invention can improve the iron recovery rate and the CaF2 recovery rate while taking into account the grades of the iron concentrate and the fluorite concentrate. In addition, the method of the present invention can reduce the feed grade of the iron and fluorite associated ores, reduce the amount of surrounding rock stripping, and improve the comprehensive utilization level of the mine. According to the preferred technical solution of the present invention, by controlling the particle size, dry pre-selection at a specific particle size and a specific magnetic field intensity, and the cooperation of using an optoelectronic separator, the number of flotation times can be reduced, which is beneficial to improving the iron recovery rate and the CaF2 recovery rate while taking into account the grades of the iron concentrate and the fluorite concentrate. Detailed implementation manners

[0027] The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0028] The general flotation process refers to scraping out the required minerals with the foam, that is, the so-called positive flotation. During the flotation process, the process of leaving the required minerals in the flotation cell and scraping out the gangue minerals with the foam is called reverse flotation.

[0029] Those skilled in the art know that there is no general method for pre-enriching iron concentrate and fluorite concentrate from the ores associated with iron ore and fluorite ore, especially for the associated ores with different contents and compositions. The method for pre-enriching iron concentrate and fluorite concentrate from the ores associated with iron and calcium fluoride of the present invention is more applicable to the ores associated with iron and calcium fluoride with a total iron grade of greater than or equal to 13.5 wt% and a CaF2 content of greater than or equal to 12 wt%.

[0030] The method for pre - enriching iron concentrate and fluorite concentrate from iron and calcium fluoride associated ores of the present invention comprises the following steps: I) Steps for obtaining iron concentrate, dry - separated iron coarse tailings, and dry - separated iron tailings; II) Steps for obtaining fluorite concentrate. Among them, step I) specifically includes: 1) Steps for ore crushing and screening to obtain fine - sized products and medium - sized products; 2) Steps for further processing the medium - sized products to obtain dry - separated iron coarse tailings, dry - separated iron tailings, and iron fine - sized products; 3) Steps for obtaining iron concentrate. Step II) includes the following specific steps: 4) Steps for combining and processing the dry - separated iron coarse tailings and dry - separated iron tailings to obtain fluorite fine - sized products; 5) Steps for obtaining fluorite concentrate. Optionally, step II) further includes: Steps for obtaining dry - separated final tailings. The following is a detailed description.

[0031] <Steps for obtaining iron concentrate, dry - separated iron coarse tailings, and dry - separated iron tailings>

[0032] Steps of ore crushing and screening to obtain fine-grained products and medium-grained products

[0033] The iron and calcium fluoride associated ores are successively subjected to coarse crushing and medium crushing to obtain medium - crushed products; the medium - crushed products are screened to obtain fine - sized products and medium - sized products. This is beneficial to improving the iron recovery rate of iron concentrate and taking into account the iron grade of iron concentrate.

[0034] In the iron and calcium fluoride associated ores, the total iron grade is greater than or equal to 13.5 wt%, preferably 14 - 20 wt%, more preferably 15 - 20 wt%. The CaF2 content is greater than or equal to 12 wt%, preferably 13 - 19 wt%, more preferably 15 - 18 wt%. The CaO content is 24 - 29 wt%, preferably 25 - 28.5 wt%. The SiO2 content is 10 - 22 wt%, preferably 10.5 - 21 wt%. The Al2O3 content is 3.5 - 4.3 wt%, preferably 3.7 - 4.2 wt%. The Na2O content is 1.5 - 1.7 wt%, preferably 1.55 - 1.65 wt%. The K2O content is 0.9 - 1.1 wt%, preferably 1.0 - 1.1 wt%. The REO content is 1 - 4.5 wt%, preferably 1.3 - 4.4 wt%. When such iron and calcium fluoride associated ores adopt the pre - enrichment method of the present invention, it is possible to take into account the grades of the obtained iron concentrate and fluorite concentrate while improving the iron recovery rate and CaF2 recovery rate.

[0035] In the present invention, the coarse crushing can be carried out by a gyratory crusher or a jaw crusher. The coarse crushing can obtain coarse - crushed products with a particle size less than 300 mm.

[0036] The coarse - crushed products are subjected to medium crushing, and the medium crushing is carried out by a standard - type cone crusher. The particle size of the medium - crushed products is less than or equal to 60 mm.

[0037] The medium-crushed product is screened to obtain fine-grained product, medium-grained product, and coarse-grained product. Among them, the particle size of the fine-grained product is less than 12 mm, the particle size of the medium-grained product is greater than or equal to 12 mm and less than 60 mm, and the particle size of the coarse-grained product is greater than or equal to 60 mm. In the present invention, it is preferred to return the coarse-grained product to the medium-crushing step and screen it until the particle size of the screened product is less than 60 mm, that is, equivalent to the medium-grained product, and then merge it with the aforementioned medium-grained product for the next treatment.

[0038] The screening is carried out using a double-deck circular vibrating screen with square screen holes having sizes of 12 mm and 60 mm respectively.

[0039] Steps of further processing the medium-grained products to obtain dry-selection iron coarse tailings, dry-selection iron tailings, and iron fine-grained products

[0040] The medium-grained product is subjected to dry pre-selection under a drum surface magnetic field intensity of 260 - 350 mT to obtain dry-selection iron rough concentrate and dry-selection iron rough tailings. The drum surface magnetic field intensity is preferably 280 - 340 mT, more preferably 300 - 330 mT, such as 320 mT.

[0041] According to an embodiment of the present invention, the medium-grained product is subjected to dry pre-selection using a magnetic pulley under a drum surface magnetic field intensity of 260 - 350 mT to obtain dry-selection iron rough concentrate and dry-selection iron rough tailings.

[0042] The dry-selection iron rough concentrate is finely crushed to obtain a finely crushed product. The fine crushing is carried out using a short-head type cone crusher.

[0043] The finely crushed product is screened to obtain a first iron fine-grained product with a particle size less than 12 mm and an iron coarse-grained product with a particle size greater than or equal to 12 mm. The screening is carried out using a single-deck circular vibrating screen with a square screen hole having a size of 12 mm.

[0044] The iron coarse-grained product with a particle size greater than or equal to 12 mm is subjected to dry pre-selection under a drum surface magnetic field intensity of 260 - 350 mT to obtain dry-selection iron concentrate and dry-selection iron tailings. The dry-selection iron concentrate is returned to the fine crushing and screening until the particle size of the screened product is less than 12 mm to obtain a second iron fine-grained product. The particle sizes of the second iron fine-grained product and the first iron fine-grained product are basically the same. In the next treatment, the two can be merged for treatment.

[0045] According to an embodiment of the present invention, the iron coarse-grained product with a particle size greater than or equal to 12 mm is subjected to dry pre-selection using a magnetic pulley under a drum surface magnetic field intensity of 260 - 350 mT to obtain dry-selection iron concentrate and dry-selection iron tailings. The drum surface magnetic field intensity is preferably 280 - 340 mT, more preferably 300 - 330 mT, such as 320 mT.

[0046] In the dry-separated iron concentrate of the present invention, the iron grade is greater than 15 wt%, and the iron recovery rate is greater than 85%.

[0047] Steps of obtaining iron concentrate

[0048] The fine-grained products, the first iron fine-grained product, and the second iron fine-grained product are combined to obtain a combined fine-grained product, and the combined fine-grained product is successively ball-milled, magnetic-separated, and reverse-flotation separated to obtain iron concentrate.

[0049] The specific steps of ball milling, magnetic separation, and reverse flotation include: ball milling the combined fine-grained product until the content of particles with a particle size less than 0.074 mm accounts for 88-92% to obtain a milled product; subjecting the milled product to two magnetic separations at a magnetic separation field strength of 200-220 mT to obtain a rough iron concentrate; re-ball milling the rough iron concentrate until the content of particles with a particle size less than 0.045 mm accounts for 70-80% to obtain a re-milled product; subjecting the re-milled product to one reverse flotation to obtain iron concentrate; wherein, the pulp concentration of the reverse flotation is 36-40 wt%, the temperature is 30-35 °C, the pH is 8-9, the collector is a modified product of sodium oleate, and the inhibitor is sodium silicate; based on the weight of the re-milled product, the dosages of the collector and the inhibitor are 0.5-1.0 kg / t and 0.8-1.2 kg / t respectively. The modified product of sodium oleate comes from Baotou Mengrong Fine Materials Co., Ltd., and the model is 506F.

[0050] In the present invention, the iron grade of the obtained iron concentrate is greater than or equal to 62 wt%, preferably greater than or equal to 64 wt%, more preferably greater than or equal to 65 wt%; the iron recovery rate is greater than or equal to 60%, preferably greater than or equal to 61%, more preferably greater than or equal to 65%.

[0051] The calculation formula for the iron recovery rate of iron concentrate is: Iron recovery rate = (weight of iron concentrate × iron grade of iron concentrate) / (iron grade of raw ore × weight of raw ore) × 100%.

[0052] <Steps for obtaining fluorite concentrate>

[0053] Steps of combining and processing the dry-selection iron coarse tailings and dry-selection iron tailings to obtain fluorite fine-grained products

[0054] The dry-separated rough iron tailings and the dry-separated iron tailings are combined to obtain combined iron tailings, and the combined iron tailings are subjected to dry pre-selection by an optoelectronic separator to obtain dry-separated rough fluorite concentrate and dry-separated rough fluorite tailings. The optoelectronic separator is preferably an XRT intelligent optoelectronic separator, and its source is not particularly limited. This can balance the grade and recovery rate of the obtained fluorite concentrate.

[0055] The dry-separated fluorite rough concentrate is finely crushed and screened to obtain a fluorite fine-grained product with a particle size less than 12 mm and a fluorite coarse-grained product with a particle size greater than or equal to 12 mm. A short-head cone crusher is used for fine crushing. A single-layer circular vibrating screen is used for screening, the screen holes are square, and the size is 12 mm.

[0056] The fluorite coarse-grained product with a particle size greater than or equal to 12 mm is further subjected to dry pre-selection by an optoelectronic separator to obtain a dry-separated fluorite concentrate and a dry-separated fluorite tailing. The optoelectronic separator is preferably an XRT intelligent optoelectronic separator, and its source is not particularly limited.

[0057] The fluorite grade of the dry-separated fluorite concentrate of the present invention is greater than 20 wt%, and the fluorite recovery rate is greater than 80%.

[0058] The dry-separated fluorite concentrate is returned to fine crushing and screening until the particle size of the screened product is less than 12 mm to obtain a second fluorite fine-grained product. A short-head cone crusher is used for fine crushing. A single-layer circular vibrating screen is used for screening, the screen holes are square, and the size is 12 mm. The second fluorite fine-grained product can be combined with the fluorite fine-grained product for treatment.

[0059] Steps of obtaining fluorite concentrate

[0060] The fluorite fine-grained product and the second fluorite fine-grained product are combined to obtain a combined product; the combined product is subjected to ball milling and flotation in sequence to obtain a fluorite concentrate.

[0061] The specific steps of ball milling and flotation include: ball milling the combined product until the content of particles with a particle size less than 0.074 mm accounts for 90-95% to obtain a ground fluorite product;

[0062] The ground fluorite product is subjected to one rough selection and more than two fine selections to obtain a fluorite rough concentrate; among them, the pulp concentration of one rough selection is 35-40 wt%, the pulp concentration of more than two fine selections is 25-28 wt%, the flotation temperature is 30-35 °C, and the pH is 8-9; the inhibitors used in one rough selection and more than two fine selections are both water glass; the collector used in one rough selection is a modified product of sodium oleate. Based on the weight of the ground fluorite product, in each flotation, the dosage of the inhibitor is 2.0-3.5 kg / t; in one rough selection, the dosage of the collector is 0-2.0 kg / t, preferably 1.0-2.0 kg / t; no collector is used in more than two fine selections; more than two fine selections can be three fine selections;

[0063] The crude fluorite concentrate is reground until the content of particles with a particle size less than 0.028 mm accounts for 90 - 95%, obtaining a reground fluorite product; the reground fluorite product is subjected to multiple selections to obtain a fluorite concentrate; among them, the pulp concentration for multiple selections is 15 - 35 wt%, the temperature is 30 - 40 °C, the pH is 4.5 - 6.0, the inhibitors used are acidic sodium silicate and tannic acid, the collector is phthalic acid, and the frother is No. 2 oil. Based on the weight of the reground fluorite product, in each selection, the dosages of acidic sodium silicate, tannic acid, phthalic acid, and No. 2 oil are 0.2 - 0.5 kg / t, 0.1 - 0.6 kg / t, 0.3 - 1.0 kg / t, and 0.1 - 0.2 kg / t respectively; the acidic sodium silicate is formed from sulfuric acid and sodium silicate with a mass ratio of 2.8 - 3.2:1.

[0064] Among them, the sodium oleate modified product is provided by Baotou Mengrong Fine Materials Co., Ltd., with the model 506F. Multiple selections are preferably four or more times of selections, more preferably four to eight times of selections, such as five times of selections. The mass ratio of sulfuric acid to sodium silicate in the acidic sodium silicate is preferably 2.9 - 3:1.

[0065] The fluorite grade of the fluorite concentrate obtained by the present invention is greater than or equal to 80 wt%, and the fluorite recovery rate is greater than or equal to 50%.

[0066] The calculation formula for the fluorite recovery rate (i.e., the CaF₂ recovery rate) of the fluorite concentrate is: CaF₂ recovery rate = (mass of fluorite concentrate × fluorite grade of fluorite concentrate (calculated as CaF₂)) / (grade of raw ore (calculated as CaF₂) × mass of raw ore) × 100%.

[0067] Steps of obtaining dry-selection final tailings

[0068] The dry - separated fluorite tailings and dry - separated crude fluorite tailings are combined into dry - separated final tailings. The iron grade of the dry - separated final tailings is less than 5 wt%, and the fluorite grade is less than 5 wt% (i.e., the CaF₂ content is less than 5 wt%).

[0069] The following introduces the test methods:

[0070] Total iron grade: Tested according to the method described in GB / T 6730.5 - 2022 of the national standard.

[0071] CaF₂ content (i.e., fluorite grade): Tested according to the method described in GB / T 5195.1 - 2017 of the national standard.

[0072] Example 1

[0073] In this embodiment, the iron and calcium fluoride co-associated ore is the iron-bearing surrounding rock of Bayan Obo, with a total iron grade of 15 wt%, a CaF₂ content of 15 wt%, a CaO content of 28.35 wt%, a SiO₂ content of 20.78 wt%, an Al₂O₃ content of 4.12 wt%, a Na₂O content of 1.62 wt%, a K₂O content of 1.05 wt%, and a REO content of 4.35 wt%.

[0074] The iron and calcium fluoride co-associated ore is first coarsely crushed by a jaw crusher to obtain a coarsely crushed product. The coarsely crushed product is then medium-crushed by a standard cone crusher to obtain a medium-crushed product. The medium-crushed product is screened by a double-deck circular vibrating screen to obtain fine-grained products, medium-grained products, and coarse-grained products respectively. The coarse-grained products are returned to the medium-crushing until the particle size of the screened products meets the requirements of the medium-grained products and are combined with the aforementioned medium-grained products for the next treatment. Among them, the particle size of the fine-grained products is less than 12 mm, the particle size of the medium-grained products is greater than or equal to 12 mm and less than 60 mm, and the particle size of the coarse-grained products is greater than or equal to 60 mm.

[0075] The medium-grained products are dry-preselected by a magnetic pulley at a drum surface magnetic field intensity of 320 mT to obtain dry-separated iron rough concentrates and dry-separated iron rough tailings. The dry-separated iron rough concentrates are finely crushed by a short-head cone crusher to obtain a finely crushed product. The finely crushed product is screened by a single-deck circular vibrating screen to obtain a first iron fine-grained product with a particle size less than 12 mm and an iron coarse-grained product with a particle size greater than or equal to 12 mm. The iron coarse-grained products with a particle size greater than or equal to 12 mm are dry-preselected by a magnetic pulley at a drum surface magnetic field intensity of 320 mT to obtain dry-separated iron concentrates and dry-separated iron tailings. The dry-separated iron concentrates are returned to the fine-crushing and screening until the particle size of the screened products is less than 12 mm, obtaining a second iron fine-grained product.

[0076] The fine-grained products, the first iron fine-grained product, and the second iron fine-grained product are combined to obtain a combined fine-grained product; the combined fine-grained product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 90% to obtain a milled product; the milled product is magnetically separated twice at a magnetic separation field intensity of 200 mT to obtain iron rough concentrates; the iron rough concentrates are ball-milled again until the content of particles with a particle size less than 0.045 mm accounts for 80% to obtain a re-milled product; the re-milled product is subjected to one-time reverse flotation to obtain iron concentrates. Among them, the pulp concentration of the reverse flotation is 40 wt%, the temperature is 35 °C, the pH is 9, the collector is the modified product 506F of sodium oleate (provided by Baotou City Mengrong Fine Materials Co., Ltd.), and the inhibitor is water glass; based on the weight of the re-milled product, the dosages of the collector and the inhibitor are 0.75 kg / t and 1.0 kg / t respectively.

[0077] The dry-selection iron coarse tailings and dry-selection iron tailings are combined and subjected to dry pre-selection by an XRT intelligent optoelectronic separator to obtain dry-selection fluorite rough concentrate and dry-selection fluorite rough tailings. The dry-selection fluorite rough concentrate is finely crushed by a short-head cone crusher and then screened by a single-layer circular vibrating screen to obtain a fluorite fine-grained product with a particle size less than 12 mm and a fluorite coarse-grained product with a particle size greater than or equal to 12 mm; the fluorite coarse-grained product with a particle size greater than or equal to 12 mm is further subjected to dry pre-selection by an XRT intelligent optoelectronic separator to obtain dry-selection fluorite concentrate and dry-selection fluorite tailings. The dry-selection fluorite concentrate is returned to fine crushing and screening until the particle size of the screened product is less than or equal to 12 mm to obtain a second fluorite fine-grained product.

[0078] The fluorite fine-grained product and the second fluorite fine-grained product are combined to obtain a combined product, and the combined product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 93% to obtain a milled fluorite product;

[0079] The milled fluorite product is subjected to one rough selection and three fine selections, and the middlings are combined and returned to obtain fluorite rough concentrate; among them, the pulp concentration of the one rough selection is 40 wt%, the pulp concentrations of the three fine selections are 28 wt%, 26 wt%, and 25 wt% respectively, the flotation temperature is 35 °C, and the pH is 9; the inhibitors used in the one rough selection and the three fine selections are all water glass, and the collector used in the one rough selection is a modified product 506F of sodium oleate (provided by Baotou City Mengrong Fine Materials Co., Ltd.). Based on the weight of the milled fluorite product, in the one rough selection, the dosages of the inhibitor and the collector are 2.0 kg / t and 1.5 kg / t respectively; no collector is added in the three fine selections, and the dosages of the inhibitor water glass in the three fine selections are 0.30 kg / t, 0.15 kg / t, and 0.15 kg / t respectively;

[0080] The rough concentrate of fluorite is reground until the content of particles with a particle size less than 0.028 mm accounts for 90%, and the reground fluorite product is obtained; the reground fluorite product is subjected to five-stage beneficiation, and the middlings are sequentially returned to obtain fluorite concentrate. Among them, the pulp concentrations for the five-stage beneficiation are 30 wt%, 28 wt%, 25 wt%, 22 wt%, and 20 wt% respectively, the temperature is 35 °C, the pH is 5.5, the inhibitors used are acid water glass and tannic acid, the collector is phthalic acid, and the foaming agent is No. 2 oil. Based on the weight of the reground fluorite product, in the five-stage beneficiation, the dosages of acid water glass are 0.5 kg / t, 0.3 kg / t, 0.3 kg / t, 0.2 kg / t, and 0.2 kg / t respectively, the dosages of tannic acid are 0.6 kg / t, 0.4 kg / t, 0.3 kg / t, 0.3 kg / t, and 0.3 kg / t respectively, the dosage of phthalic acid is 0.85 kg / t for all, and the dosages of No. 2 oil are 0.15 kg / t, 0.10 kg / t, 0.10 kg / t, 0.10 kg / t, and 0.10 kg / t respectively. The acid water glass is formed from sulfuric acid and water glass with a mass ratio of 3:1.

[0081] The dry-selection rough tailings of fluorite and the dry-selection tailings of fluorite are combined into the final dry-selection tailings.

[0082] Example 2

[0083] In this embodiment, the iron and calcium fluoride associated ore is the original ore to be selected in Bayan Obo Concentrator of Baotou Steel, with a total iron grade of 20 wt%, a CaF₂ content of 18 wt%, a CaO content of 25.87 wt%, a SiO₂ content of 10.78 wt%, an Al₂O₃ content of 4.12 wt%, a Na₂O content of 1.62 wt%, a K₂O content of 1.05 wt%, and a REO content of 1.35 wt%.

[0084] The iron and calcium fluoride associated ore is first coarsely crushed by a jaw crusher to obtain a coarsely crushed product. The coarsely crushed product is medium-crushed by a standard cone crusher to obtain a medium-crushed product. The medium-crushed product is screened by a double-deck circular vibrating screen to obtain fine-grained products, medium-grained products, and coarse-grained products respectively. The coarse-grained products are returned to the medium-crushing until the particle size of the screened products meets the requirements of the medium-grained products, and are combined with the aforementioned medium-grained products for the next treatment. Among them, the particle size of the fine-grained products is less than 12 mm, the particle size of the medium-grained products is greater than or equal to 12 mm and less than 60 mm, and the particle size of the coarse-grained products is greater than or equal to 60 mm.

[0085] The medium-sized products are subjected to dry pre-selection using a magnetic pulley at a drum surface magnetic field intensity of 320 mT to obtain dry-selection iron rough concentrate and dry-selection iron rough tailings. The dry-selection iron rough concentrate is finely crushed using a short-head cone crusher to obtain a finely crushed product. The finely crushed product is screened using a single-layer circular vibrating screen to obtain a first iron fine-grained product with a particle size less than 12 mm and an iron coarse-grained product with a particle size greater than or equal to 12 mm. The iron coarse-grained product with a particle size greater than or equal to 12 mm is subjected to dry pre-selection using a magnetic pulley at a drum surface magnetic field intensity of 320 mT to obtain dry-selection iron concentrate and dry-selection iron tailings. The dry-selection iron concentrate is returned to fine crushing and screening until the particle size of the screened product is less than 12 mm to obtain a second iron fine-grained product.

[0086] The fine-grained products, the first iron fine-grained product, and the second iron fine-grained product are combined to obtain a combined fine-grained product; the combined fine-grained product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 89% to obtain a milled product; the milled product is subjected to magnetic separation twice at a magnetic separation field intensity of 200 mT to obtain iron rough concentrate; the iron rough concentrate is ball-milled again until the content of particles with a particle size less than 0.045 mm accounts for 78% to obtain a re-milled product; the re-milled product is subjected to one-time reverse flotation to obtain iron concentrate. Among them, the pulp concentration of reverse flotation is 40 wt%, the temperature is 33 °C, the pH is 8.5, the collector is the modified product 506F of sodium oleate (provided by Baotou Mengrong Fine Materials Co., Ltd.), and the inhibitor is water glass; based on the weight of the re-milled product, the dosages of the collector and the inhibitor are 0.75 kg / t and 0.9 kg / t respectively.

[0087] The dry-selection iron rough tailings and the dry-selection iron tailings are combined and subjected to dry pre-selection using an XRT intelligent optoelectronic separator to obtain dry-selection fluorite rough concentrate and dry-selection fluorite rough tailings. The dry-selection fluorite rough concentrate is finely crushed using a short-head cone crusher and then screened using a single-layer circular vibrating screen to obtain a fluorite fine-grained product with a particle size less than 12 mm and a fluorite coarse-grained product with a particle size greater than or equal to 12 mm. The fluorite coarse-grained product with a particle size greater than or equal to 12 mm is subjected to dry pre-selection again using an XRT intelligent optoelectronic separator to obtain dry-selection fluorite concentrate and dry-selection fluorite tailings. The dry-selection fluorite concentrate is returned to fine crushing and screening until the particle size of the screened product is less than 12 mm to obtain a second fluorite fine-grained product.

[0088] The fluorite fine-grained product and the second fluorite fine-grained product are combined to obtain a combined product, and the combined product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 93% to obtain a milled fluorite product;

[0089] The ground fluorite product is subjected to a primary roughing and a tertiary concentrating, and the intermediate ore is combined and returned to obtain a fluorite coarse concentrate; wherein the pulp concentration of the primary roughing is 40wt%, and the pulp concentrations of the tertiary concentrating are 28wt%, 26wt%, and 25wt% respectively, the flotation temperature is 35°C, and the pH is 9; the inhibitors used in the primary roughing and the tertiary concentrating are all water glass, and the collector used in the primary roughing is a sodium oleate modified product 506F (provided by Baotou Mengrong Fine Materials Co., Ltd.); based on the weight of the ground fluorite product, the dosage of the inhibitor and the collector in the primary roughing are 2.5kg / t and 1.8kg / t respectively; no collector is added in the tertiary concentrating, and the dosage of the inhibitor water glass in the tertiary concentrating is 0.20kg / t, 0.2kg / t, and 0.10kg / t respectively;

[0090] The fluorite coarse concentrate is ball-milled again until the content of particles with a particle size of less than 0.028 mm accounts for 95%, thereby obtaining a reground fluorite product; the reground fluorite product is subjected to five rounds of beneficiation, and the intermediate ore is sequentially returned to obtain a fluorite concentrate. The pulp concentrations of the five times of selection are 30wt%, 28wt%, 25wt%, 22wt%, and 16wt%, respectively, the temperature is 35°C, the pH is 5.5, the inhibitors used are acidic water glass and tannic acid, the collector is phthalic acid, and the foaming agent is 2# oil. Based on the weight of the reground fluorite product, in the five times of selection, the amount of acidic water glass is 0.4kg / t, 0.4kg / t, 0.3kg / t, 0.2kg / t, and 0.2kg / t, the amount of tannic acid is 0.5kg / t, 0.4kg / t, 0.4kg / t, 0.3kg / t, and 0.2kg / t, the amount of phthalic acid is 1.0kg / t, and the amount of 2# oil is 0.12kg / t. The acidic water glass is formed by sulfuric acid and water glass in a mass ratio of 3:1.

[0091] The dry-separated fluorite coarse tailings and the dry-separated fluorite tailings are combined into the dry-separated final tailings.

[0092] Table 1

[0093]

[0094] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A method for pre - enriching iron concentrate and fluorite concentrate from iron and calcium fluoride associated ores, characterized in that, Including the following steps: 1) Coarse-crush and medium-crush the iron and calcium fluoride associated ore in sequence to obtain a medium-crushed product; screen the medium-crushed product to obtain a fine-grained product and a medium-grained product; wherein, the particle size of the fine-grained product is less than 12 mm, and the particle size of the medium-grained product is greater than or equal to 12 mm and less than 60 mm; 2) Dry-preselect the medium-grained product under a drum surface magnetic field intensity of 260 - 350 mT to obtain a dry-selected iron rough concentrate and a dry-selected iron rough tailing; fine-crush the dry-selected iron rough concentrate to obtain a fine-crushed product; screen the fine-crushed product to obtain a first iron fine-grained product with a particle size less than 12 mm and an iron coarse-grained product with a particle size greater than or equal to 12 mm; dry-preselect the iron coarse-grained product under a drum surface magnetic field intensity of 260 - 350 mT to obtain a dry-selected iron concentrate and a dry-selected iron tailing; return the dry-selected iron concentrate to the fine-crushing step for fine-crushing and screening until the particle size of the screened product is less than 12 mm to obtain a second iron fine-grained product; 3) Combine the fine-grained product, the first iron fine-grained product, and the second iron fine-grained product, and perform ball milling, magnetic separation, and reverse flotation in sequence to obtain iron concentrate; 4) Combine the dry-selected iron rough tailing and the dry-selected iron tailing to obtain a combined iron tailing; dry-preselect the combined iron tailing by an optoelectronic separator to obtain a dry-selected fluorite rough concentrate and a dry-selected fluorite rough tailing; fine-crush and screen the dry-selected fluorite rough concentrate to obtain a fluorite fine-grained product with a particle size less than 12 mm and a fluorite coarse-grained product with a particle size greater than or equal to 12 mm; dry-preselect the fluorite coarse-grained product by an optoelectronic separator again to obtain a dry-selected fluorite concentrate and a dry-selected fluorite tailing; return the dry-selected fluorite concentrate to the fine-crushing step for fine-crushing and screening until the particle size of the screened product is less than 12 mm to obtain a second fluorite fine-grained product; 5) Combine the fluorite fine-grained product and the second fluorite fine-grained product to obtain a combined product, and perform ball milling and flotation on the combined product in sequence to obtain fluorite concentrate.

2. The method according to claim 1, wherein In the iron and calcium fluoride associated ore, the total iron grade is greater than or equal to 13.5 wt%, and the CaF2 content is greater than or equal to 12 wt%.

3. The method according to claim 1, characterized in that, In step 1), a gyratory crusher or a jaw crusher is used for coarse crushing; a cone crusher is used for medium crushing.

4. The method according to claim 1, characterized in that In step 2), a magnetic pulley is used for dry preselection under a drum surface magnetic field intensity of 260 - 350 mT.

5. The method according to claim 1, characterized in that In steps 2) and 4), a single-layer circular vibrating screen is used for screening.

6. The method according to claim 1, wherein In step 3), the fine-grained products, the first iron fine-grained products and the second iron fine-grained products are combined to obtain a combined fine-grained product; the combined fine-grained product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 88-92% to obtain a grinding product; the grinding product is subjected to two magnetic separations at a magnetic separation field intensity of 200-220 mT to obtain a rough iron concentrate; the rough iron concentrate is ball-milled again until the content of particles with a particle size less than 0.045 mm accounts for 70-80% to obtain a re-ground product; the re-ground product is subjected to one reverse flotation to obtain an iron concentrate; wherein, the pulp concentration of the reverse flotation is 36-40 wt%, the temperature is 30-35 °C, the pH is 8-9, the collector is a modified product of sodium oleate, and the inhibitor is water glass; based on the weight of the re-ground product, the dosages of the collector and the inhibitor are 0.5-1.0 kg / t and 0.8-1.2 kg / t respectively.

7. The method according to claim 1, wherein The photoelectric separator is an XRT intelligent photoelectric separator.

8. The method according to claim 1, wherein In step 5), the fluorite fine-grained product and the second fluorite fine-grained product are combined to obtain a combined product; the combined product is ball-milled until the content of particles with a particle size less than 0.074 mm accounts for 90-95% to obtain a ground fluorite product; The ground fluorite product is subjected to one rough selection and more than two fine selections to obtain a rough fluorite concentrate; wherein, the pulp concentration of the one rough selection is 35-40 wt%, the pulp concentration of the more than two fine selections is 25-28 wt%, the flotation temperature is 30-35 °C, and the pH is 8-9; the inhibitor used in the one rough selection and the more than two fine selections is water glass, and the collector used in the one rough selection is a modified product of sodium oleate; based on the weight of the ground fluorite product, in each flotation, the dosage of the inhibitor is 2.0-3.5 kg / t; in the one rough selection, the dosage of the collector is 0-2.0 kg / t; The rough fluorite concentrate is ball-milled again until the content of particles with a particle size less than 0.028 mm accounts for 90-95% to obtain a re-ground fluorite product; the re-ground fluorite product is subjected to multiple fine selections to obtain a fluorite concentrate; wherein, the pulp concentration of the multiple fine selections is 15-35 wt%, the temperature is 30-40 °C, the pH is 4.5-6.0, the inhibitor used is acidic water glass and tannic acid, the collector is phthalic acid, and the foaming agent is No. 2 oil; based on the weight of the re-ground fluorite product, in each fine selection, the dosages of acidic water glass, tannic acid, phthalic acid and No. 2 oil are 0.2-0.5 kg / t, 0.1-0.6 kg / t, 0.3-1.0 kg / t and 0.1-0.2 kg / t respectively; the acidic water glass is formed by sulfuric acid and water glass with a mass ratio of 2.8-3.2:

1.

9. The method according to any one of claims 1 to 8, characterized in that It also includes: The dry-selection fluorite tailings and the dry-selection fluorite rough tailings are combined into dry-selection final tailings.

10. The method according to claim 1, wherein The iron recovery rate in the obtained iron concentrate is greater than or equal to 60%, and the CaF2 recovery rate in the obtained fluorite concentrate is greater than or equal to 50%.

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