A scheelite beneficiation method and its application

Abstract

The present invention relates to a scheelite beneficiation method and application, comprising the following steps: thickening a scheelite coarse concentrate slurry to obtain a slurry A having a solid content of 20 to 75 wt%; mixing slurry A with a pH adjuster, a fatty alcohol polyoxyethylene ether, a de-agent, and a collector, and stirring for 0.5 to 5 hours to obtain a slurry B; and diluting slurry B before performing a room temperature concentration operation to obtain a scheelite concentrate. The tungsten concentrate obtained by the beneficiation method of the present invention exhibits excellent grade and recovery rates, with the WO3 grade increased by 3% to 8%, the WO3 recovery rate increased by 3% to 6%, and the beneficiation indicators more stable.

Description

Technical Field

[0001] The present invention relates to a scheelite beneficiation method and application, in particular to a scheelite beneficiation method and application at room temperature, belonging to the field of ore beneficiation. Background Art

[0002] Scheelite ore is primarily composed of scheelite, calcite, fluorite, dolomite, apatite, quartz, and other silicate minerals. Scheelite is typically finely interbedded. Flotation is the primary beneficiation method for fine-grained scheelite. However, since scheelite, calcite, fluorite, dolomite, and apatite are all calcium-containing minerals with similar surface properties, the differences in floatability between these minerals are minimal in a fatty acid collector system. Furthermore, the content of calcium-containing gangue minerals is often higher than that of scheelite. Therefore, separating scheelite from calcium-containing gangue minerals is challenging.

[0003] The most common flotation method for scheelite is the "Petrov process," which consists of two parts: a normal-temperature pre-flotation process and a heated concentration process. The normal-temperature pre-flotation process removes most of the quartz and silicate gangue, typically enriching the WO3 content of the coarse concentrate to above 0.8wt%. The heated concentration process, by adding a large amount of water glass as a de-refining agent, desorbs collector molecules adsorbed on the surfaces of calcium-containing minerals such as calcite and fluorite at high temperatures, while leaving those adsorbed on the scheelite surface unaffected, effectively separating the scheelite from the calcium-containing minerals. However, this method requires heating, which consumes a lot of energy and is costly, and the heating system also has some environmental pollution. Normal-temperature concentration technology, which does not require heating, consumes less energy, is less costly, and has minimal environmental pollution, making it an inevitable trend in industrial development for normal-temperature concentration to replace heated concentration technology.

[0004] At present, the main reasons why room temperature concentration technology has not been widely used in scheelite are: the concentrate grade and recovery rate of room temperature concentration are lower than those of heated concentration, and the mineral processing indicators are greatly affected by the mineral composition of the feed ore, and the stability is insufficient. After extensive experimental research, the applicant found that the main reasons why room temperature concentration indicators are inferior to heated concentration are as follows:

[0005] (1) During heating and concentration, increasing the slurry temperature can increase the thermal motion of the collector molecules, causing the collector molecules adsorbed on the surface of calcium-containing gangue minerals such as calcite and fluorite to fall off and re-adsorb the newly added water glass, making the surface of calcium-containing gangue minerals such as calcite and fluorite hydrophilic, thereby achieving the purpose of inhibiting calcium-containing gangue minerals. The adsorption of collector molecules on the surface of scheelite is hydrogen bonding. The energy of heating is not enough to make the collector molecules separate from the surface of scheelite. Therefore, the surface of scheelite still has strong hydrophobicity. Therefore, the hydrophobicity difference between scheelite and calcium-containing gangue minerals is significant, resulting in a better separation effect. During room temperature concentration, due to the lack of external heat energy input, the collector on the mineral surface can only be desorbed by mechanical stirring. After mechanical stirring, the collector on the surface of calcium-containing gangue minerals is not fully desorbed, and the collector on the surface of scheelite is inevitably desorbed, resulting in a decrease in the floatability of scheelite. Ultimately, the separation efficiency of scheelite and calcium-containing gangue minerals is low.

[0006] (2) Under heating conditions, water glass has higher activity and can better disperse the pulp and reduce the impact of fine-grained gangue minerals on the flotation process of scheelite. Under normal temperature conditions, the dispersion effect of water glass on the pulp is not as good as under heating.

[0007] (3) During the normal temperature concentration process, fine-grained gangue minerals will be enriched in the middlings. During the flotation process, fine-grained gangue minerals are easily adsorbed or covered on the surface of scheelite, causing the floatability of scheelite to deteriorate, resulting in a lower concentrate grade and a lower recovery rate.

[0008] Therefore, how to effectively improve the drug removal selectivity during the stirring process, reduce or eliminate the influence of fine-grained gangue minerals, and expand the floatability difference between scheelite and calcium-containing gangue minerals is the key to improving the mineral processing indicators of the normal temperature concentration process. Summary of the Invention

[0009] In view of the shortcomings of the existing technology, one of the objects of the present invention is to provide a beneficiation method for scheelite to improve the beneficiation indicators such as concentrate grade and recovery rate; the second object of the present invention is to provide the application of fatty alcohol polyoxyethylene ether in the flotation separation of scheelite and calcium-containing gangue minerals.

[0010] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0011] A method for beneficiating scheelite, characterized by comprising the following steps:

[0012] S1. Provide scheelite crude concentrate slurry;

[0013] The content of WO3 in the scheelite crude concentrate is 0.60-12.00 wt%, further 0.8-8.0 wt%, and the total content of calcium gangue minerals is ≥8.0 wt%;

[0014] S2, thickening the scheelite crude concentrate slurry to obtain slurry A with a solid content of 20 to 75 wt%;

[0015] S3. Add a pH adjuster, fatty alcohol polyoxyethylene ether, a de-agent, and a collector to the slurry A obtained in S2 in sequence, and stir for 0.5 to 5 hours to obtain slurry B;

[0016] The dosage of the pH adjuster is 0-5 kg / t of feed ore (1 t of feed ore refers to 1 ton of scheelite crude concentrate); the dosage of the fatty alcohol polyoxyethylene ether is 0.05-5 kg / t of feed ore; the dosage of the de-agent is 35-90 kg / t of feed ore; the collector is oleic acid or saponified oleic acid, and the dosage of the collector is 100-500 g / t of feed ore;

[0017] S4. After diluting the pulp B obtained in S3, perform concentration flotation operation at room temperature to obtain scheelite concentrate.

[0018] The present invention increases the floatability difference between scheelite and calcium-containing gangue minerals by adding a certain amount of fatty alcohol polyoxyethylene ether and stirring for a certain period of time under the combined action of mechanical stirring, fatty alcohol polyoxyethylene ether, a de-agent, etc., thereby improving the grade and recovery rate of tungsten concentrate and stabilizing mineral processing indicators.

[0019] Furthermore, in S1, the scheelite crude concentrate slurry is obtained by pre-selecting the scheelite ore at room temperature. Furthermore, the scheelite crude concentrate slurry has a concentration of 25-45 wt%.

[0020] Furthermore, the room temperature pre-selection process is as follows: the scheelite ore is mixed with water and ground in a ball mill to form a scheelite ore pulp. Sodium carbonate or sodium hydroxide is added to the pulp in sequence to adjust the pH value, and an inhibitor and a collector are added to the pulp. The pulp then enters a flotation machine or a flotation column for aeration flotation to obtain scheelite rough concentrate and rougher tailings.

[0021] Optionally, the scheelite ore is skarn-type scheelite.

[0022] Furthermore, in S1, the calcium-containing gangue minerals are mainly fluorite and calcite; in the coarse scheelite concentrate, the content of fluorite is 10-75wt%, further 12-28wt%, and the content of calcite is 10-50wt%, further 24-46wt%.

[0023] Furthermore, in S2, the solid content of the slurry A is 25-70 wt%, further 40-65 wt%, and further 45-60 wt%.

[0024] Furthermore, in S2, the thickening process is performed by using one of a rake thickener, a high-efficiency thickener, and a deep cone thickener, or the thickening process may not be performed.

[0025] Furthermore, S3 is performed in a mixing barrel. Optionally, the diameter of the mixing barrel is 1.5 to 4.5 meters, the height of the mixing barrel is 2 to 4.5 meters, and the diameter of the mixing impeller is 1 to 3.5 meters.

[0026] Furthermore, in S3, the stirring speed is 30-400 r / min, which helps to obtain better separation effect and is conducive to industrial application.

[0027] Furthermore, in S3, the pH adjuster includes one or both of sodium hydroxide and sodium sulfide; the de-acidifying agent is water glass, and preferably, the modulus of the water glass is 1.8 to 2.8.

[0028] Furthermore, in S3, the polymerization degree of the fatty alcohol polyoxyethylene ether is 7-9.

[0029] Furthermore, in S3, the amount of fatty alcohol polyoxyethylene ether used is 0.5-4 kg / t of feed ore.

[0030] Furthermore, in S3, a pH adjuster is first added to pulp A and stirred for 5 to 15 minutes, then fatty alcohol polyoxyethylene ether is added and stirred for 5 to 15 minutes, then a de-agent is added and stirred for 1.5 to 2.5 hours, and finally a collector is added and stirred for 5 to 15 minutes to obtain pulp B. This helps to achieve better separation results.

[0031] Furthermore, in S4, the concentration of the slurry B obtained in S3 is diluted to 20-30 wt%.

[0032] Furthermore, in S4, the room temperature flotation operation includes one roughing operation, 2 to 6 concentrating operations, and 2 to 4 scavenging operations; during this period, the tailings (middlings) obtained from the first concentrating operation are returned to step S2 or S3, the tailings (middlings) obtained from the remaining concentrating operations are returned to the previous operation in sequence, and the concentrates obtained from each scavenging operation are returned to the previous operation in sequence. In this way, the floatability difference between the scheelite and the calcium-containing gangue minerals in the tailings (middlings 1) obtained from the first concentrating operation can be increased under the combined action of mechanical stirring, fatty alcohol polyoxyethylene ether, and a de-agent, thereby improving the grade of the tungsten concentrate, improving the recovery rate, and stabilizing the mineral processing indicators.

[0033] Based on the same inventive concept, the present invention also provides the use of fatty alcohol polyoxyethylene ether in the flotation separation of scheelite concentrate and calcium-containing gangue minerals, wherein the collector is oleic acid or saponified oleic acid.

[0034] Furthermore, the polymerization degree of the fatty alcohol polyoxyethylene ether is 7-9.

[0035] Furthermore, the dosage of the fatty alcohol polyoxyethylene ether is 0.05-5 kg / t of feed ore, and further 0.5-4 kg / t of feed ore.

[0036] In particular, the present invention can solve the problem of large fluctuations in the normal temperature concentration indexes of scheelite, and has important guiding significance for achieving normal temperature concentration in scheelite mines.

[0037] The applicant's research has discovered that fatty alcohol polyoxyethylene ethers have a solubilizing effect on fatty acid collectors. Fatty alcohol polyoxyethylene ethers can also disperse fatty acid collectors adsorbed on mineral surfaces into the ore slurry, thereby causing the collectors adsorbed on the mineral surface to fall off. In particular, the applicant discovered that adding fatty alcohol polyoxyethylene ethers to the ambient temperature concentration of scheelite effectively improves mineral processing performance. This is explained as follows: fatty alcohol polyoxyethylene ether molecules selectively adsorb on the surfaces of calcium-containing gangue minerals, making the collector molecules more easily detached from these surfaces. Fatty alcohol polyoxyethylene ether molecules, on the other hand, are less adsorbed on the scheelite surface, thereby improving the selectivity of the collector removal process and facilitating the flotation separation of scheelite and calcium-containing gangue minerals. In addition, by returning the selected 1 tailings (mid-ore 1) to the mixing barrel or thickener, under the combined action of fatty alcohol polyoxyethylene ether and mechanical force, the collector molecules on the surface of the gangue minerals in the mid-ore 1 are again analyzed, and after the gangue minerals adsorb the fatty alcohol polyoxyethylene ether molecules, they are more easily dispersed by the de-agent, which significantly reduces the influence of fine-grained gangue minerals on the flotation of scheelite.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) Compared with the existing room temperature concentration process for scheelite, the concentrate obtained by the mineral processing method of the present invention has excellent indicators such as grade and recovery rate. The WO3 grade is increased by 3% to 8%, the WO3 recovery rate is increased by 3% to 6%, and the mineral processing indicators are more stable.

[0040] (2) The present invention does not require major changes to the original production process. It only requires adding fatty alcohol polyoxyethylene ether during the drug removal process and adjusting the treatment method of the middling ore, which is easy to apply industrially. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a graph showing the flotation test results of scheelite, fluorite, and calcite under different dosages of fatty alcohol polyoxyethylene ether in Example 1.

[0042] Figure 2 This is a flow chart of the pure mineral flotation process of Example 1.

[0043] Figure 3 This is the normal temperature selection process flow chart of Comparative Example 1.

[0044] Figure 4 This is a flow chart of the normal temperature selection process of Examples 2 to 13.

[0045] Figure 5 This is the normal temperature selection process flow chart of Comparative Example 2.

[0046] Figure 6 This is a flow chart of the normal temperature selection process of Example 14. DETAILED DESCRIPTION

[0047] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that, unless otherwise specified, the embodiments and features of the embodiments of the present invention may be combined with each other. Unless otherwise specified, the relevant percentages are percentages by mass.

[0048] Example 1

[0049] In order to better illustrate the working principle of fatty alcohol polyoxyethylene ether, experiments were conducted on pure minerals (mineral purity greater than 95%) such as scheelite, fluorite, and calcite by adding fatty alcohol polyoxyethylene ether.

[0050] Pure mineral test: Prepare the corresponding pure mineral, add oleic acid (100g / t) and stir for 2 minutes. Then add a certain amount of fatty alcohol polyoxyethylene ether (DP 7-9) and stir for 20 minutes to obtain slurry. Flotation is performed on the slurry for 4 minutes to obtain concentrate and tailings.

[0051] Figure 1 The flotation test results of the corresponding minerals under different dosage conditions of fatty alcohol polyoxyethylene ether in Example 1 are as follows: Figure 1 The data show that as the dosage of fatty alcohol polyoxyethylene ether increases, the flotation recoveries of the three minerals decrease, and the fluorite recovery rate decreases the most, the calcite recovery rate decreases moderately, and the scheelite recovery rate decreases the least. When the dosage of fatty alcohol polyoxyethylene ether reaches 1.5kg / t and continues to increase, the recoveries of the three minerals no longer change significantly. This shows that the amount of collector (oleic acid) molecules adsorbed on the fluorite surface is the largest, and therefore the fluorite recovery rate decreases the most. Therefore, it can be inferred that: the adsorption amount of fatty alcohol polyoxyethylene ether on the fluorite surface is the largest; the desorption amount of collector molecules adsorbed on the calcite surface is moderate, and therefore the calcite recovery rate decreases moderately, indicating that the adsorption amount of fatty alcohol polyoxyethylene ether on the calcite surface is moderate; while the collector molecules adsorbed on the scheelite surface have little effect, and therefore the scheelite recovery rate has the least effect, indicating that the adsorption amount of fatty alcohol polyoxyethylene ether on the scheelite surface is small.

[0052] Therefore, fatty alcohol polyoxyethylene ether is selectively adsorbed on the surfaces of the three minerals, with a large adsorption amount on the surfaces of fluorite and calcite, and a small adsorption amount on the surface of scheelite.

[0053] Examples 2 to 9

[0054] The method of the present invention was used to conduct a room temperature concentration test (field test) on the coarse concentrate slurry after the thickening treatment of a tungsten mine in Henan Province:

[0055] The coarse concentrate slurry is obtained from the scheelite ore through a normal temperature pre-selection process and a thickening process;

[0056] In order to control a single variable, the coarse concentrate slurry used in Examples 2 to 9 was derived from the same batch of tungsten ore samples. The WO3 content, CaF2 content, and CaCO3 content in the coarse concentrate slurry were 1.366%, 19.28%, and 30.25%, respectively, and the slurry concentration was 70%.

[0057] Add 1kg / t of sodium hydroxide to the concentrated coarse concentrate and stir for 10 minutes; then add a certain amount of fatty alcohol polyoxyethylene ether (polymerization degree 7-9) and stir for 10 minutes; then add 60kg / t of water glass (modulus 1.8-2.2) and stir for 120 minutes; add 300g / t of collector (saponified oleic acid) and stir for 10 minutes to obtain slurry;

[0058] The slurry is diluted to a concentration of 28%, and enters a process flow of 1 roughing operation - 4 cleaning operations - 3 scavenging operations, and the tailings of the selected 1 are returned to the mixing tank. In each scavenging operation, 80g / t of collector (saponified oleic acid) is added to obtain tungsten concentrate and cleaned tailings.

[0059] Table 1 Results of room temperature selection tests under different fatty alcohol polyoxyethylene ether dosages in Examples 2 to 9

[0060]

[0061]

[0062] As shown in Table 1, when the amount of fatty alcohol polyoxyethylene ether is too small (less than 0.5kg / t), the recovery rate of WO3 in room temperature concentration is improved slightly. If the amount of fatty alcohol polyoxyethylene ether is increased, the recovery rate of WO3 in room temperature concentration will continue to increase. If the amount of fatty alcohol polyoxyethylene ether is too large (greater than 4kg / t), the recovery rate of WO3 in room temperature concentration will begin to decrease if the amount of fatty alcohol polyoxyethylene ether is increased. It can be seen that when the amount of fatty alcohol polyoxyethylene ether is too small or too large, it is not conducive to improving the recovery rate of WO3 in room temperature concentration. When the amount of fatty alcohol polyoxyethylene ether is in the range of 0.5kg / t to 4kg / t, the recovery rate of WO3 in tungsten concentrate is high, the WO3 grade is high, and the mineral processing indicators of room temperature concentration are better.

[0063] Examples 10 to 12

[0064] The method of the present invention was used to conduct a room temperature concentration test (field test) on the coarse concentrate slurry after the thickening treatment of a tungsten mine in Henan Province:

[0065] The coarse concentrate slurry is obtained from the scheelite ore after pre-selection and thickening.

[0066] In order to control a single variable, the coarse concentrate slurry used in Examples 10 to 12 was derived from the same batch of tungsten ore samples, wherein the WO3 content in the coarse concentrate slurry was 1.366%, the CaF2 content was 19.28%, the CaCO3 content was 30.25%, and the slurry concentration was 70%;

[0067] Add 1kg / t of sodium hydroxide to the concentrated coarse concentrate and stir for 10 minutes; then add 1kg / t of fatty alcohol polyoxyethylene ether with different polymerization degrees and stir for 10 minutes; then add 60kg / t of water glass (modulus 1.8-2.2) and stir for 120 minutes; then add 300g / t of collector (saponified oleic acid) and stir for 10 minutes to obtain slurry;

[0068] The slurry is diluted to a concentration of 28%, and enters a process flow of 1 roughing operation - 4 cleaning operations - 3 scavenging operations, and the tailings of the selected 1 are returned to the mixing tank. In each scavenging operation, 80g / t of collector (saponified oleic acid) is added to obtain tungsten concentrate and cleaned tailings.

[0069] Table 2 Results of room temperature selection tests of fatty alcohol polyoxyethylene ethers with different polymerization degrees in Examples 10 to 12

[0070]

[0071] As shown in Table 2, compared with other fatty alcohol polyoxyethylene ethers with different polymerization degrees, fatty alcohol polyoxyethylene ethers with a polymerization degree of 7-9 provide the highest WO3 grade and recovery rate for room-temperature concentration of tungsten concentrate. This indicates that fatty alcohol polyoxyethylene ethers with a polymerization degree of 7-9 are suitable for room-temperature concentration of scheelite.

[0072] Comparative Example 1

[0073] The conventional room temperature concentration process was used to conduct a room temperature concentration test (field test) on the coarse concentrate slurry after the thickening treatment of a tungsten mine in Henan Province:

[0074] The coarse concentrate slurry is obtained from the scheelite ore after pre-selection and thickening.

[0075] The WO3 content in the coarse concentrate is 0.60% to 1.83%, the CaF2 content is 18.00% to 20.00%, the CaCO3 content is 25.00% to 40.00%, and the pulp concentration is 68% to 72%;

[0076] Add 1kg / t of sodium hydroxide to the concentrated coarse concentrate and stir for 10 minutes; then add 60kg / t of water glass (modulus 1.8-2.2) and stir for 120 minutes; then add 300g / t of collector (saponified oleic acid) and stir for 10 minutes to obtain slurry;

[0077] The slurry is diluted to a concentration of 27% to 29%, and enters a process flow of 1 roughing operation - 4 concentrating operations - 3 scavenging operations, and the middlings are returned in sequence. In each scavenging operation, 80g / t of collector (saponified oleic acid) is added to obtain tungsten concentrate and concentrating tailings.

[0078] Table 3 Comparative Example 1 Conventional room temperature concentration process test results

[0079]

[0080] Note: In Table 3, repetitions 1 to 4 are for different feed grades.

[0081] Example 13

[0082] The method of the present invention was used to conduct a room temperature concentration test (field test) on the coarse concentrate slurry after the thickening treatment of a tungsten mine in Henan Province:

[0083] The coarse concentrate slurry is obtained from the scheelite ore after pre-selection and thickening.

[0084] The WO3 content in the coarse concentrate is 0.60% to 1.83%, the CaF2 content is 18.00% to 20.00%, the CaCO3 content is 25.00% to 40.00%, and the pulp concentration is 68% to 72%;

[0085] In a stirring barrel, 1 kg / t of sodium hydroxide was added to the concentrated coarse concentrate and stirred for 10 minutes; 1 kg / t of fatty alcohol polyoxyethylene ether (polymerization degree 7-9) was added and stirred for 10 minutes; then 60 kg / t of water glass (modulus 1.8-2.2) was added and stirred for 120 minutes, and 300 g / t of collector (saponified oleic acid) was added and stirred for 10 minutes to obtain slurry;

[0086] The slurry is diluted to a concentration of 27% to 29%, and enters a process flow of 1 roughing operation - 4 cleaning operations - 3 scavenging operations, and the tailings of the selected 1 are returned to the mixing tank. In each scavenging operation, 80g / t of collector (saponified oleic acid) is added to obtain tungsten concentrate and cleaned tailings.

[0087] Table 4: Results of room temperature selection test of Example 13

[0088]

[0089] Note: In Table 4, repetitions 1 to 4 are for feed ores of different grades.

[0090] By comparing Table 3 and Table 4, it can be seen that compared with the conventional room temperature concentration process, the present invention obtains a high-grade tungsten concentrate by adding fatty alcohol polyoxyethylene ether and returning the concentrated 1 tailings (mid-ore 1) to the stirring barrel, and the recovery rate is significantly improved, and the recovery rate index for different grades of feed ores is more stable.

[0091] Comparative Example 2

[0092] A conventional room temperature concentration process was used to conduct a room temperature concentration test (field test) on the coarse concentrate slurry after thickening treatment of a tungsten mine in Hunan:

[0093] The coarse concentrate slurry is obtained from the scheelite ore after pre-selection and thickening.

[0094] The WO3 content in the coarse concentrate is 4.21% to 8.53%, the CaF2 content is 10.00% to 15.00%, the CaCO3 content is 30% to 40%, and the pulp concentration is 65% to 68%;

[0095] Add 1kg / t of sodium hydroxide to the concentrated coarse concentrate and stir for 10 minutes; then add 80kg / t of water glass (modulus 2.5-2.7) and stir for 120 minutes; then add 200g / t of collector (saponified oleic acid) and stir for 10 minutes to obtain slurry;

[0096] The slurry is diluted to a concentration of 25% to 27%, and enters a process flow of 1 roughing operation - 5 concentrating operations - 3 scavenging operations, and the middlings are returned in sequence. In each scavenging operation, 60g / t of collector (saponified oleic acid) is added to obtain tungsten concentrate and concentrating tailings.

[0097] Table 5 Comparative Example 2 Conventional process room temperature selection test results

[0098]

[0099] Note: In Table 5, repetitions 1 to 3 are for feed ores of different grades.

[0100] Example 14

[0101] The method of the present invention was used to conduct a room temperature concentration test on the coarse concentrate pulp after the thickening treatment of a tungsten mine in Hunan:

[0102] The coarse concentrate slurry is obtained from the scheelite ore after pre-selection and thickening.

[0103] The coarse concentrate pulp has a WO3 content of 4.21% to 8.53%, a CaF2 content of 10.00% to 15.00%, a CaCO3 content of 30.00% to 40.00%, and a pulp concentration of 65% to 68%;

[0104] Add 1kg / t of sodium hydroxide to the concentrated coarse concentrate and stir for 10 minutes; then add 0.5kg / t of fatty alcohol polyoxyethylene ether (polymerization degree 7-9) and stir for 10 minutes, then add 80kg / t of water glass (modulus 2.5-2.7) and stir for 120 minutes; then add 200g / t of collector (saponified oleic acid) and stir for 10 minutes to obtain slurry;

[0105] The slurry is diluted to a concentration of 25% to 27%, and enters a process flow of 1 roughing operation - 5 cleaning operations - 3 scavenging operations, and the tailings of the selected 1 are returned to the thickener, wherein 60g / t of collector (saponified oleic acid) is added to each scavenging operation to obtain tungsten concentrate and cleaned tailings.

[0106] Table 6 Results of room temperature selection test of Example 14

[0107]

[0108] Note: In Table 6, repetitions 1 to 3 are for feed ores of different grades.

[0109] By comparing Table 5 and Table 6, it can be seen that compared with the conventional room temperature concentration process, the present invention adopts the method of adding fatty alcohol polyoxyethylene ether and returning the concentrated 1 tailings (middling ore 1) to the thickener, which can obtain a high-grade tungsten concentrate, and the recovery rate index for different grades of feed ores is more stable.

[0110] The contents illustrated in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent modifications of the present invention by those skilled in the art shall fall within the scope defined by the claims attached to this application.

Claims

1. A method for beneficiating scheelite, characterized in that: The steps include: S1. Provide scheelite crude concentrate slurry; The content of WO3 in the scheelite crude concentrate is 0.60-12.00wt%, and the total content of calcium gangue minerals is ≥8.00wt%; S2, thickening the scheelite crude concentrate slurry to obtain slurry A with a solid content of 20-75 wt%; S3. Add a pH adjuster, fatty alcohol polyoxyethylene ether, a de-agent, and a collector to the slurry A obtained in S2 in sequence, and stir for 0.5-5 hours to obtain slurry B; The dosage of the pH adjuster is 0-5 kg / t of feed ore; the dosage of the fatty alcohol polyoxyethylene ether is 0.5-5 kg / t of feed ore; the dosage of the de-acidifying agent is 35-90 kg / t of feed ore; the collector is oleic acid or saponified oleic acid, and the dosage of the collector is 100-500 g / t of feed ore; the degree of polymerization of the fatty alcohol polyoxyethylene ether is 7-9; S4: After diluting the pulp B obtained in S3, it enters the normal temperature concentration flotation operation to obtain scheelite concentrate.

2. The mineral processing method according to claim 1, characterized in that: In S4, the normal temperature concentration flotation operation includes 1 roughing operation, 2 to 6 concentration operations and 2 to 4 scavenging operations; during this period, the tailings obtained from the first concentration operation are returned to step S2 or S3, the tailings obtained from the remaining concentration operations are returned to the previous operation in sequence, and the concentrates obtained from each scavenging operation are returned to the previous operation in sequence.

3. The mineral processing method according to claim 1, characterized in that: In S3, the dosage of fatty alcohol polyoxyethylene ether is 0.5~4kg / t feed ore.

4. The mineral processing method according to any one of claims 1 to 3, characterized in that: In S1, the calcium-containing gangue minerals are mainly fluorite and calcite; in the scheelite crude concentrate, the content of fluorite is 10-30wt%, and the content of calcite is 20-50wt%.

5. The mineral processing method according to any one of claims 1 to 3, characterized in that: In S3, first add the pH adjuster to the pulp A and stir for 5-15 minutes, then add the fatty alcohol polyoxyethylene ether and stir for 5-15 minutes, then add the de-agent and stir for 1.5-2.5 hours, and finally add the collector and stir for 5-15 minutes to obtain pulp B.

6. The mineral processing method according to any one of claims 1 to 3, characterized in that: In S3, the pH adjuster includes one or both of sodium hydroxide and sodium sulfide; and the de-acidifying agent is water glass.

7. The mineral processing method according to claim 6, characterized in that: The modulus of water glass is 1.8~2.8.

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