A beneficiation method for high-calcium and high-iron scheelite

Abstract

This invention relates to the field of mineral processing technology, specifically disclosing a beneficiation method for high-calcium and high-iron scheelite. The beneficiation method for high-calcium and high-iron scheelite provided by this invention removes calcium and iron in stages, achieving efficient extraction of scheelite and demonstrating strong applicability. This invention overcomes the interference of calcium- and iron-containing gangue minerals on scheelite flotation, reduces the addition of large amounts of water glass reagents during flotation, improves tailings settling performance, reduces tailings wastewater treatment and reuse costs, and achieves clean production of scheelite concentrate.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a beneficiation method for high-calcium, high-iron scheelite. Background Technology

[0002] Tungsten (W) is a typical rare metal with excellent physicochemical properties, widely used in cemented carbide, electronics, and defense technology. my country has abundant scheelite resources, but most are low-grade and fine-grained, and are associated with large amounts of calcium- and iron-bearing gangue minerals such as calcite, fluorite, apatite, garnet, mica, diopside, and amphibole. These minerals have similar surface properties or dissolution characteristics to scheelite, severely hindering the efficient recovery of scheelite.

[0003] Currently, scheelite is mainly recovered using flotation or a combined process based on flotation. The common method involves using sodium carbonate as a modifier, water glass as a depressant, and fatty acids as a collector for rough scheelite separation to obtain a rough concentrate. Then, a large amount of water glass is added as a modifier, followed by heated refining to obtain a final scheelite concentrate. However, existing scheelite processing technologies require the addition of large amounts of water glass as a modifier. Under natural settling conditions, the tailings water remains largely unclarified, increasing the difficulty and cost of tailings and wastewater treatment and hindering clean production.

[0004] To address the aforementioned problems in scheelite beneficiation, it is necessary to develop scheelite beneficiation methods that are more conducive to cleaner production. Summary of the Invention

[0005] The main technical problem solved by this invention is to provide a beneficiation method for high-calcium and high-iron scheelite, which overcomes the interference of calcium- and iron-containing gangue minerals on the flotation of scheelite, reduces the addition of a large amount of water glass reagent during the flotation process, improves the settling performance of tailings, reduces the cost of tailings wastewater treatment and reuse, and achieves clean production.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a beneficiation method for high-calcium and high-iron scheelite, comprising the following steps:

[0007] S1: Crushing and grinding the raw scheelite ore to a fineness of -0.074mm, accounting for 65-85%, adjusting the slurry to a slurry concentration of 30-55%, then adding modifiers, collectors, and frothers, and carrying out sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings;

[0008] S2: The sulfide tailings are magnetically separated to remove iron, resulting in magnetic concentrate and magnetic tailings;

[0009] S3: The magnetic separation tailings are treated with hydrocyclones for decalcification, resulting in hydrocyclone underflow and hydrocyclone overflow; the hydrocyclone decalcification treatment includes 1-3 stages of hydrocyclone grading.

[0010] S4: Add modifier, collector and frother to the hydrocyclone sand, adjust the slurry to a slurry concentration of 45-55% and a pH of 6-7, and carry out calcium-iron flotation to obtain calcium-iron flotation concentrate and calcium-iron flotation tailings.

[0011] S5: The calcium-iron flotation tailings are subjected to scheelite flotation to obtain scheelite rough concentrate; the scheelite flotation includes 1-2 roughing stages, 1-3 scavenging stages, and 2-5 cleaning stages; the pH of the scheelite flotation slurry is 8-9.5;

[0012] S6: The scheelite rough concentrate is further refined to obtain scheelite concentrate. The refining is carried out by centrifugal beneficiation, and the centrifugal drum speed is 100-500 r / min.

[0013] In one embodiment of the present invention, in step S1, the modifier is selected from sulfuric acid, copper sulfate, and sodium sulfide; the collector is butyl xanthate; and the foaming agent is pine oil.

[0014] In one embodiment of the present invention, in step S2, the magnetic field strength of the magnetic separation is 1500-5000GS.

[0015] Preferably, in step S2, the magnetic separation is performed once or twice.

[0016] During a single magnetic separation, the magnetic field strength is 4000-5000 GS;

[0017] The two magnetic separation processes consist of a roughing process and a sweeping process. The magnetic field strength for the roughing process is 1500-3000 GS, and the magnetic field strength for the sweeping process is 4000-5000 GS.

[0018] As one embodiment of the present invention, in step S3, the hydrocyclone decalcification treatment includes performing 2-3 stages of hydrocyclone grading treatment.

[0019] Preferably, when performing two-stage hydrocyclone grading, the feed pressure for the first-stage hydrocyclone operation is 0.20-0.25 MPa, and the feed pressure for the second-stage hydrocyclone operation is 0.15-0.18 MPa.

[0020] When performing three-stage hydrocyclone classification, the feed pressure for the first-stage hydrocyclone is 0.18-0.22 MPa, the feed pressure for the second-stage hydrocyclone is 0.15-0.18 MPa, and the feed pressure for the third-stage hydrocyclone is 0.10-0.16 MPa.

[0021] In one embodiment of the present invention, in step S4, the modifier is one or more of lime, sodium carbonate, and sodium hydroxide; the collector is one or more of butyl xanthate, pentyl xanthate, and oleic acid soap; and the foaming agent is pine oil.

[0022] Preferably, in step S4, the dosage of the modifier is 100-200 g / t of raw ore, the dosage of the collector is 100-210 g / t of raw ore, and the dosage of the frother is 1-10 g / t of raw ore.

[0023] In one embodiment of the present invention, in step S5, the reagents used in the roughing process include a roughing modifier, an activator, and a collector, and the roughing process yields a roughing concentrate and a roughing tailings.

[0024] Preferably, in step S5, the coarse selection modifier is sodium carbonate or a combination of sodium carbonate and any one of carboxymethyl cellulose, sodium hexametaphosphate, sodium lignosulfonate, and sodium fluorosilicate; the activator is lead nitrate; and the collector is benzohydroxyxamic acid or a mixture of benzohydroxyxamic acid and oleic acid soap or pine oil.

[0025] Preferably, in step S5, the amount of sodium carbonate used is 1000-3000 g / t of raw ore, the amount of any one of carboxymethyl cellulose, sodium hexametaphosphate, sodium lignosulfonate, and sodium fluorosilicate is 0-100 g / t of raw ore, the amount of lead nitrate is 500-1500 g / t of raw ore, the amount of benzohydroxyxamic acid is 300-800 g / t of raw ore, and the amount of any one of oleic acid soap or pine oil is 1-15 g / t of raw ore.

[0026] In one embodiment of the present invention, in step S5, the reagents used in the scavenging process include a scavenging collector, and the roughing tailings are scavenged to obtain scavenging concentrate and scavenging tailings.

[0027] Preferably, the scavenging collector is benzohydroxyxamic acid or a mixture of benzohydroxyxamic acid and oleic acid soap.

[0028] More preferably, the amount of benzohydroxyxamic acid used is 200-300 g / t of raw ore, and the amount of oleic acid soap used is 0-2 g / t of raw ore.

[0029] In one embodiment of the present invention, in step S5, the reagents used for the refining process include a refining modifier and a refining collector, and the rough concentrate is refined to obtain scheelite rough concentrate and middlings.

[0030] Preferably, the selected modifier is modified water glass, and the selected collector is benzohydroxyxamic acid or a mixture of benzohydroxyxamic acid and pinyl oil.

[0031] More preferably, the amount of modified water glass is 100-300 g / t of raw ore, the amount of benzohydroxyxamic acid is 50-100 g / t of raw ore, and the amount of pine oil is 0-5 g / t of raw ore.

[0032] In one embodiment of the present invention, the scavenged concentrate and the middlings are sequentially returned to the previous stage of operation.

[0033] The present invention provides a beneficiation method for high-calcium and high-iron scheelite. First, the raw scheelite ore is crushed and ground to a particle size of -0.074mm, with 65-85% of the particles being smaller than 0.074mm (i.e., the mass percentage of minerals with a particle size less than 0.074mm is 65-85%). After slurry preparation, a modifier, collector, and frother are added to the slurry, followed by sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings, thus removing sulfide ore. The obtained sulfide ore concentrate mainly consists of pyrite, pyrrhotite, sphalerite, and other minerals. The sulfide ore tailings are then subjected to magnetic separation to remove iron, yielding magnetic concentrate and magnetic tailings. Magnetic separation removes some iron minerals, and the magnetic concentrate mainly consists of magnetite, pyrrhotite, goethite, and other minerals. The magnetic tailings are then treated with a hydrocyclone for decalcification, yielding hydrocyclone... The process involves settling sand and hydrocyclone overflow. The hydrocyclone overflow mainly contains calcium-containing minerals such as calcite, fluorite, dolomite, and mica. After the hydrocyclone settling sand is slurry conditioned, calcium-iron flotation is performed. Flotation removes some calcium-iron gangue minerals, and further separation removes calcium and iron, yielding calcium-iron flotation concentrate and tailings. The calcium-iron flotation concentrate mainly contains calcite, dolomite, apatite, garnet, chlorite, and amphibole. Scheelite is enriched in the calcium-iron flotation tailings, which are then subjected to scheelite flotation to obtain scheelite rough concentrate. Because impurities such as calcium and iron that affect scheelite flotation are effectively removed in the previous steps, the amount of modified water glass used in scheelite flotation is significantly reduced, requiring only 100-300 g / t of modified water glass per ton of raw scheelite ore. The scheelite rough concentrate is then further refined to obtain scheelite concentrate.

[0034] The beneficiation method for high-calcium and high-iron scheelite provided by this invention removes calcium and iron in stages, achieving efficient extraction of scheelite and demonstrating strong applicability. This invention overcomes the interference of calcium- and iron-containing gangue minerals on scheelite flotation, reduces the amount of water glass reagent added during flotation, improves tailings settling performance, and lowers the cost of tailings wastewater treatment and reuse.

[0035] The scheelite concentrate obtained by the method of this invention has a high WO3 content and a high tungsten recovery rate, with WO3 content ranging from 38% to 60%, and a tungsten recovery rate of over 46% for the raw scheelite ore. Furthermore, the total tailings obtained by this method, i.e., the tailings obtained after combining scheelite flotation tailings and the refined tailings from scheelite rough concentrate, exhibit excellent settling properties. Under natural settling conditions, complete settling occurs within a maximum of 50 minutes, resulting in clear tailings water. This significantly reduces the difficulty of tailings and wastewater treatment, substantially lowers treatment costs, and achieves clean production of scheelite concentrate. Attached Figure Description

[0036] Figure 1 This invention provides a process flow diagram for the beneficiation of high-calcium and high-iron scheelite.

[0037] Figure 2 These are natural settling curves obtained from natural settling experiments conducted on the total tailings obtained in Examples 1-4. Detailed Implementation

[0038] The technical solution of the present invention will be described in detail below through specific embodiments.

[0039] In the following examples, all pharmaceutical agents used are commercially available products. All percentages in the examples are by mass.

[0040] The dosage of the reagents is based on the mass of the raw scheelite ore. For example, adding 1000g / t of sodium carbonate means adding 1000g of sodium carbonate per ton of raw scheelite ore.

[0041] Example 1

[0042] This embodiment provides a beneficiation method for high-calcium, high-iron scheelite, referring to... Figure 1 The process flow diagram shown is used. The elemental analysis of the processed scheelite ore is as follows:

[0043] The content of WO3 is 0.18%, the content of CaO is 11.91%, the content of Fe is 25.96%, and the content of S is 19.69%.

[0044] The processing steps in this embodiment are as follows:

[0045] Step 1: Grind the raw scheelite ore to a particle size of -0.074mm (72%), adjust the pulp concentration to 42%, add 600g / t copper sulfate, 150g / t butyl xanthate, and 20g / t pine oil, and carry out sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings;

[0046] Step 2: After the sulfide tailings are thoroughly stirred, they are subjected to magnetic separation, including one roughing and one scavenging process, with magnetic field strengths of 3000GS and 5000GS, respectively, to obtain magnetic concentrate and magnetic tailings.

[0047] Step 3: The magnetic separation tailings are classified by two hydrocyclones. The feed pressure of the first hydrocyclone is 0.20 MPa and the feed pressure of the second hydrocyclone is 0.18 MPa. Hydrocyclone underflow and hydrocyclone overflow are obtained. All the underflow from the two hydrocyclones is combined and enters the next flotation step.

[0048] Step 4: Add 100g / t sodium carbonate, 100g / t butyl xanthate, 20g / t pentyl xanthate, 10g / t oleic acid soap, and 2g / t pine oil to the hydrocyclone sediment. Adjust the slurry to a flotation concentration of 45% and a pH of 7.0. Perform flotation to obtain calcium-iron flotation concentrate and calcium-iron flotation tailings.

[0049] Step 5: Perform scheelite flotation on the calcium-iron flotation tailings at a pH of 8.5. The flotation process is as follows:

[0050] (1) Two roughing processes are performed to obtain roughing concentrate and roughing tailings; the reagent regime for roughing is as follows:

[0051] Coarse Selection 1: Coarse selection includes 1000g / t sodium carbonate, 100g / t carboxymethyl cellulose, 1000g / t lead nitrate, 500g / t benzohydroxyxamic acid, and 10g / t pine oil;

[0052] Coarse selection 2: Add 200g / t of lead nitrate, 100g / t of benzohydroxyxamic acid, and 2g / t of pine oil;

[0053] (2) Two scavenging processes: The roughing tailings are scavenged twice to obtain scavenged concentrate and scavenged tailings; the reagent system for scavenging is as follows: 200 g / t of benzohydroxyxamic acid and 1 g / t of oleic acid soap are added.

[0054] (3) Four-stage refining: The rough concentrate is refined four times to obtain scheelite rough concentrate and middlings; the reagent system for refining is as follows: 100g / t of modified water glass, 100g / t of benzohydroxyxamic acid and 5g / t of pine oil are added.

[0055] The selected middlings and scavenged concentrate are returned sequentially to the previous operation.

[0056] Step 6: The scheelite rough concentrate is fed into a centrifuge for further cleaning. The centrifuge drum rotates at 300 r / min. The centrifuge cleaning process yields scheelite concentrate and cleaned tailings.

[0057] The obtained scheelite concentrate contained 46.19% WO3, and the tungsten recovery rate from the original ore was 46.69%.

[0058] The obtained sulfide concentrate contains 42.10% S and 35.69% Fe, the magnetic separation concentrate contains 28.71% S and 54.23% Fe, and the calcium-iron flotation concentrate contains 6.72% S, 12.36% Fe, and 36.05% CaO.

[0059] Example 2

[0060] This embodiment provides a beneficiation method for high-calcium, high-iron scheelite, referring to... Figure 1 The process flow diagram shown is used. The elemental analysis of the processed scheelite ore is as follows:

[0061] The content of WO3 is 0.12%, the content of CaO is 10.10%, the content of Fe is 24.00%, and the content of S is 13.34%.

[0062] The processing steps in this embodiment are as follows:

[0063] Step 1: Grind the raw scheelite ore to a particle size of -0.074mm (80%), adjust the pulp concentration to 36%, add 100g / t sodium sulfide, 100g / t butyl xanthate, and 10g / t pine oil, and carry out sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings.

[0064] Step 2: After the sulfide tailings are thoroughly stirred, they are subjected to magnetic separation. After one roughing and one scavenging, the magnetic field strengths are 1500 Gs and 4000 Gs, respectively, to obtain magnetic concentrate and magnetic tailings.

[0065] Step 3: The magnetic separation tailings are classified by three hydrocyclones. The feed pressures of the three hydrocyclones are 0.20MPa, 0.18MPa and 0.15MPa, respectively, to obtain hydrocyclone underflow and hydrocyclone overflow. All the underflow from the three hydrocyclones is combined and enters the next flotation step.

[0066] Step 4: Add 100g / t sodium carbonate, 20g / t sodium hydroxide, 200g / t butyl xanthate, 5g / t oleic acid soap, and 10g / t pine oil to the hydrocyclone sediment. Adjust the slurry to a flotation concentration of 51% and a pH of 6.0, and carry out flotation to obtain calcium-iron flotation concentrate and calcium-iron flotation tailings.

[0067] Step 5: Perform scheelite flotation on the calcium-iron flotation tailings at a pH of 9.0. The flotation process is as follows:

[0068] (1) One roughing process is performed to obtain roughing concentrate and roughing tailings; the reagent regime for roughing is as follows:

[0069] Add 2000g / t sodium carbonate, 100g / t sodium hexametaphosphate, 800g / t lead nitrate, 700g / t benzohydroxyxamic acid, and 6g / t pine oil;

[0070] (2) Scavenging once: Scavenging is performed on the roughing tailings to obtain scavenged concentrate and scavenged tailings; the reagent system for scavenging is: 300g / t of benzohydroxyxamic acid and 2g / t of oleic acid soap are added;

[0071] (3) Five-times of fine selection: Five fine selections were performed on the rough concentrate to obtain scheelite rough concentrate and middlings; the fine selection reagent system was as follows: 200g / t of modified water glass and 50g / t of benzoic acid were added.

[0072] The selected middlings and scavenged concentrate are returned sequentially to the previous operation.

[0073] Step 6: The scheelite rough concentrate is fed into a centrifuge for further cleaning. The centrifuge drum rotates at 200 r / min. The centrifuge cleaning process yields scheelite concentrate and cleaned tailings.

[0074] The obtained scheelite concentrate contained 42.14% WO3, and the tungsten recovery rate from the original ore was 49.86%.

[0075] The obtained sulfide concentrate contains 45.56% S and 32.19% Fe, the magnetic separation concentrate contains 23.17% S and 50.32% Fe, and the calcium-iron flotation concentrate contains 10.12% S, 15.63% Fe and 31.70% CaO.

[0076] Example 3

[0077] This embodiment provides a beneficiation method for high-calcium, high-iron scheelite, referring to... Figure 1 The process flow diagram shown is used. The elemental analysis of the processed scheelite ore is as follows:

[0078] The content of WO3 is 0.15%, the content of CaO is 19.01%, the content of Fe is 28.25%, and the content of S is 24.20%.

[0079] The processing steps in this embodiment are as follows:

[0080] Step 1: Grind the raw scheelite ore to a particle size of -0.074mm (68%), adjust the pulp concentration to 47%, add 300g / t copper sulfate, 200g / t butyl xanthate, and 25g / t pine oil, and carry out sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings;

[0081] Step 2: After the sulfide tailings are thoroughly stirred, they are subjected to magnetic separation. After one magnetic separation, the magnetic field strength is 4500 Gs, and magnetic concentrate and magnetic tailings are obtained.

[0082] Step 3: The magnetic separation tailings are classified by two hydrocyclones. The feed pressures of the two hydrocyclones are 0.25MPa and 0.15MPa, respectively, to obtain hydrocyclone underflow and hydrocyclone overflow. All the underflow from the two hydrocyclones is combined and enters the next flotation step.

[0083] Step 4: Add 200g / t of lime, 100g / t of pentyl xanthate, 20g / t of oleic acid soap and 1g / t of pine oil to the hydrocyclone settling sand, adjust the slurry to a flotation concentration of 49% and a pH of 6.5, and carry out flotation to obtain calcium-iron flotation concentrate and calcium-iron flotation tailings.

[0084] Step 5: Perform scheelite flotation on the calcium-iron flotation tailings at a pH of 8.7. The flotation process is as follows:

[0085] (1) One roughing process is performed to obtain roughing concentrate and roughing tailings; the reagent regime for roughing is as follows:

[0086] Add 1500g / t sodium carbonate, 600g / t lead nitrate, 800g / t benzohydroxyxamic acid, and 15g / t pine oil;

[0087] (2) Three scavenging processes: The roughing tailings are scavenged three times to obtain scavenged concentrate and scavenged tailings; the reagent system for scavenging is as follows: 250 g / t of benzohydroxyxamic acid and 0.5 g / t of oleic acid soap are added in total;

[0088] (3) Three-stage refining: The rough concentrate is refined three times to obtain scheelite rough concentrate and middlings; the reagent system for refining is as follows: 300g / t of modified water glass, 50g / t of benzohydroxyxamic acid, and 0.5g / t of pine oil are added.

[0089] The selected middlings and scavenged concentrate are returned sequentially to the previous operation.

[0090] Step 6: The scheelite rough concentrate is fed into a centrifuge for further cleaning. The centrifuge drum rotates at 400 r / min. The centrifuge cleaning process yields scheelite concentrate and cleaned tailings.

[0091] The obtained scheelite concentrate contained 38.74% WO3, and the tungsten recovery rate from the original ore was 56.72%.

[0092] The obtained sulfide concentrate contains 40.10% S and 31.72% Fe, the magnetic separation concentrate contains 26.13% S and 55.10% Fe, and the calcium-iron flotation concentrate contains 9.27% ​​S, 16.37% Fe, and 26.30% CaO.

[0093] Example 4

[0094] This embodiment provides a beneficiation method for high-calcium, high-iron scheelite, referring to... Figure 1 The process flow diagram shown is used. The elemental analysis of the processed scheelite ore is as follows:

[0095] The content of WO3 is 0.088%, the content of CaO is 26.10%, the content of Fe is 19.52%, and the content of S is 9.43%.

[0096] The processing steps in this embodiment are as follows:

[0097] Step 1: Grind the raw scheelite ore to a particle size of -0.074mm (78%), adjust the pulp concentration to 38%, add 200g / t sulfuric acid, 120g / t butyl xanthate, and 8g / t pine oil, and carry out sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings;

[0098] Step 2: After thorough mixing, the sulfide tailings are subjected to magnetic separation, consisting of one roughing and one scavenging process with magnetic field strengths of 1500 Gs and 4500 Gs, respectively, to obtain magnetic concentrate and magnetic tailings.

[0099] Step 3: The magnetic separation tailings are classified by two hydrocyclones. The feed pressures of the two hydrocyclones are 0.25MPa and 0.15MPa, respectively, to obtain hydrocyclone underflow and hydrocyclone overflow. All the underflow from the two hydrocyclones is combined and enters the next flotation step.

[0100] Step 4: Add 100g / t of lime, 10g / t of sodium hydroxide, 100g / t of butyl xanthate, 30g / t of oleic acid soap, and 5g / t of pine oil to the hydrocyclone sediment. Adjust the slurry to a flotation concentration of 54% and a pH of 6.5, and carry out flotation to obtain calcium-iron flotation concentrate and calcium-iron flotation tailings.

[0101] Step 5: Perform scheelite flotation on the calcium-iron flotation tailings at a pH of 9.5. The flotation process is as follows:

[0102] (1) One roughing process is performed to obtain roughing concentrate and roughing tailings; the reagent regime for roughing is as follows:

[0103] Add 3000g / t sodium carbonate, 1500g / t lead nitrate, 400g / t benzohydroxyxamic acid, and 10g / t pine oil;

[0104] (2) One scavenging: The roughing tailings are scavenged once to obtain scavenged concentrate and scavenged tailings; the reagent system for scavenging is: 200g / t of benzohydroxyxamic acid is added;

[0105] (3) Five-times of fine selection: Five fine selections were performed on the rough concentrate to obtain scheelite rough concentrate and middlings; the fine selection reagent system was as follows: 150g / t of modified water glass and 100g / t of benzoic acid were added.

[0106] The selected middlings and scavenged concentrate are returned sequentially to the previous operation.

[0107] Step 6: The scheelite rough concentrate is fed into a centrifuge for further cleaning. The centrifuge drum rotates at 500 r / min. The centrifuge cleaning process yields scheelite concentrate and cleaned tailings.

[0108] The obtained scheelite concentrate contained 54.12% WO3, and the tungsten recovery rate from the original ore was 47.62%.

[0109] The obtained sulfide concentrate contains 41.22% S and 36.02% Fe, the magnetic separation concentrate contains 21.17% S and 52.13% Fe, and the calcium-iron flotation concentrate contains 7.27% S, 11.63% Fe and 39.10% CaO.

[0110] The scavenged tailings obtained in each embodiment and the refined tailings obtained in step 6 are combined to form the total tailings of that embodiment.

[0111] The total tailings obtained in Examples 1-4 above were subjected to natural settling experiments, and the obtained natural settling curves are shown in the figure. Figure 2 .from Figure 2 It can be seen that under natural settling conditions, the total tailings in Examples 1-4 can all achieve rapid settling, and can be completely settled within 50 minutes at most. The resulting tailings water is clear, which greatly reduces the difficulty of tailings and wastewater treatment.

Claims

1. A beneficiation method for high-calcium, high-iron scheelite, characterized in that, Including the following steps: S1: Crushing and grinding the raw scheelite ore to a fineness of -0.074mm, accounting for 65-85%, adjusting the slurry to a slurry concentration of 30-55%, then adding modifiers, collectors, and frothers, and carrying out sulfide ore flotation to obtain sulfide ore concentrate and sulfide ore tailings; S2: The sulfide tailings are magnetically separated to remove iron, resulting in magnetic concentrate and magnetic tailings; S3: The magnetic separation tailings are treated with hydrocyclones for decalcification, resulting in hydrocyclone underflow and hydrocyclone overflow; the hydrocyclone decalcification treatment includes 1-3 stages of hydrocyclone grading. S4: Add modifier, collector and frother to the hydrocyclone sand, adjust the slurry to a slurry concentration of 45-55% and a pH of 6-7, and carry out calcium-iron flotation to obtain calcium-iron flotation concentrate and calcium-iron flotation tailings. S5: The calcium-iron flotation tailings are subjected to scheelite flotation to obtain scheelite rough concentrate; the scheelite flotation includes 1-2 roughing stages, 1-3 scavenging stages, and 2-5 cleaning stages; the pH of the scheelite flotation slurry is 8-9.5; S6: The scheelite rough concentrate is further refined to obtain scheelite concentrate. The refining process is carried out using a centrifuge with a drum speed of 100-500 r / min.

2. The method according to claim 1, characterized in that, In step S1, the modifier is selected from sulfuric acid, copper sulfate, and sodium sulfide; the collector is butyl xanthate; and the foaming agent is pine oil.

3. The method according to claim 1 or 2, characterized in that, In step S2, the magnetic field strength of the magnetic separation is 1500-5000 GS.

4. The method according to claim 3, characterized in that, In step S2, the magnetic separation is performed once or twice. During a single magnetic separation, the magnetic field strength is 4000-5000 GS; The two magnetic separation processes consist of a roughing process and a sweeping process. The magnetic field strength for the roughing process is 1500-3000 GS, and the magnetic field strength for the sweeping process is 4000-5000 GS.

5. The method according to claim 1, characterized in that, In step S3, the hydrocyclone decalcification process includes performing 2-3 stages of hydrocyclone grading. When performing two-stage hydrocyclone classification, the feed pressure for the first-stage hydrocyclone operation is 0.20-0.25 MPa, and the feed pressure for the second-stage hydrocyclone operation is 0.15-0.18 MPa. When performing three-stage hydrocyclone classification, the feed pressure for the first-stage hydrocyclone is 0.18-0.22 MPa, the feed pressure for the second-stage hydrocyclone is 0.15-0.18 MPa, and the feed pressure for the third-stage hydrocyclone is 0.10-0.16 MPa.

6. The method according to claim 1, characterized in that, In step S4, the modifier is one or more of lime, sodium carbonate, and sodium hydroxide; the collector is one or more of butyl xanthate, amyl xanthate, and oleic acid soap; and the foaming agent is pine oil; and / or, The dosage of the modifier is 100-200 g / t of raw ore, the dosage of the collector is 100-210 g / t of raw ore, and the dosage of the frother is 1-10 g / t of raw ore.

7. The method according to claim 1, characterized in that, In step S5, the reagents used in the roughing process include a roughing modifier, an activator, and a collector, and the roughing process yields a roughing concentrate and a roughing tailings. The coarse selection modifier is sodium carbonate or a combination of sodium carbonate and any one of carboxymethyl cellulose, sodium hexametaphosphate, sodium lignosulfonate, and sodium fluorosilicate; the activator is lead nitrate; and the collector is benzohydroxyxamic acid or a mixture of benzohydroxyxamic acid and oleic acid soap or pine oil.

8. The method according to claim 7, characterized in that, The dosage of sodium carbonate is 1000-3000 g / t of raw ore; the dosage of any one of carboxymethyl cellulose, sodium hexametaphosphate, sodium lignosulfonate, and sodium fluorosilicate is 0-100 g / t of raw ore; the dosage of lead nitrate is 500-1500 g / t of raw ore; the dosage of benzohydroxyxamic acid is 300-800 g / t of raw ore; and the dosage of any one of oleic acid soap or pine oil is 1-15 g / t of raw ore.

9. The method according to claim 7, characterized in that, In step S5, the reagents used in the scavenging process include a scavenging collector, and the roughing tailings are scavenged to obtain scavenging concentrate and scavenging tailings. The scavenging collector is benzohydroxyxamic acid or a mixture of benzohydroxyxamic acid and oleic acid soap.

10. The method according to claim 9, characterized in that, In step S5, the amount of benzohydroxyxamic acid used is 200-300 g / t of raw ore, and the amount of oleic acid soap used is 0-2 g / t of raw ore.

11. The method according to claim 9, characterized in that, In step S5, the reagents used for the refining process include a refining modifier and a refining collector, and the rough concentrate is refined to obtain scheelite rough concentrate and middlings. The selected modifier is modified water glass, and the selected collector is benzohydroxyxamic acid or a mixture of benzohydroxyxamic acid and pine oil.

12. The method according to claim 11, characterized in that, In step S5, the amount of modified water glass used is 100-300 g / t of raw ore, the amount of benzohydroxyxamic acid used is 50-100 g / t of raw ore, and the amount of pine oil used is 0-5 g / t of raw ore.

13. The method according to claim 11, characterized in that, The scavenged concentrate and the middlings are sequentially returned to the previous operation.

Images