A method for recovering uranium and gold from gold-extracting tailings of uranium-containing gold ore

Abstract

The invention discloses a method for recovering uranium and gold from gold tailings of uranium-containing gold mines. The method classifies the tailings according to the existence form and distribution of uranium and part of unleached gold in the gold tailings of uranium-containing gold mines. After the coarse-grained tailings are re-grinded, gold is recovered by centrifugal gravity separation. The gold tailings are recovered by two-step flotation. The first step is to flotate uranium minerals coexisting with sulfides, and the second step is to flotate uranium minerals in the form of oxides. During the flotation process, reasonable activators and collectors are added to achieve separation and enrichment of uranium minerals. Finally, weak magnetic uranium minerals are separated by strong magnetic separation to further reduce the uranium content in the tailings. The gold grade in the gravity gold concentrate is 9.87g / t, the recovery rate is 24.87%, the gold grade in the flotation uranium concentrate 1 is 2.52g / t, and the recovery rate is 47.07%; the uranium grade in the total uranium concentrate is 0.113%, and the recovery rate is 73.82%; the tailings yield is 86.65%, and the uranium grade is 0.004%, which can meet the radioactive exemption requirements.

Description

Technical Field

[0001] The invention relates to a method for treating tailings of gold extraction from uranium-containing gold mines, and in particular to a method for recovering uranium and gold from tailings of gold extraction from uranium-containing gold mines, belonging to the technical field of ore dressing. Background Art

[0002] At present, the most common gold ore dressing method is to extract gold from gold ore by the full mud cyanidation process. After the uranium-containing gold ore is extracted by the full mud cyanidation process, the radioactive uranium mainly remains in the tailings. The gold grade in these tailings is low, about 0.25g / t. If the cost of recovering gold alone is high, therefore, these tailings are mainly discharged into the tailings pond. However, the uranium grade in the tailings of gold extraction from uranium-containing gold ore is about 0.02%. The presence of a large amount of radioactive uranium elements will cause a certain degree of radioactive pollution to both water and the atmosphere.

[0003] The unleached gold in the gold tailings of uranium-containing gold mines is mainly wrapped by other minerals, while uranium mainly exists in the form of titanium uranium ore, crystalline uranium ore, associated uranium ore, etc., and the gold grade is about 0.25g / t, and the uranium grade is about 0.02%. The gold in the tailings exists in a wrapped state, and the grades of gold and uranium ore are low, which is the main reason for the difficulty in its ore dressing, high cost, and difficulty in achieving its comprehensive recycling, resulting in waste of resources and environmental pollution. In the prior art, there is no good comprehensive utilization method for gold tailings of uranium-containing gold mines. Summary of the invention

[0004] In view of the problem that the tailings of gold extraction from uranium-containing gold mines in the prior art have not been reasonably and comprehensively recovered, resulting in resource waste and radioactive pollution, the purpose of the present invention is to provide a beneficiation method for separating and recovering uranium and gold from the tailings of gold extraction from uranium-containing gold mines. According to the occurrence state and distribution characteristics of unleached gold and radioactive uranium in the tailings of gold extraction from uranium-containing gold mines, the method adopts a method of combining classification with regrinding and gravity separation to recover gold, and a method of combining flotation with magnetic separation to recover uranium. This method can not only reduce the uranium content in the tailings to meet the standard of radioactive exemption, but also realize the resource recovery of gold and uranium.

[0005] In order to achieve the above technical purpose, the present invention provides a method for recovering uranium and gold from gold-extracting tailings of uranium-containing gold ore, the method comprising the following steps:

[0006] 1) Screening and grading the uranium-containing gold leaching tailings to obtain coarse-grained tailings and fine-grained tailings;

[0007] 2) grinding the coarse-grained tailings and then re-selecting them using a centrifugal concentrator to obtain re-selected gold concentrate and re-selected gold tailings;

[0008] 3) the fine-grained tailings and the gravity-selected gold tailings are combined and slurried, and then enter flotation I, using oxalic acid as an activator, butyl xanthate and N-nitrosophenylamine as collectors, and adding a frother, and performing a roughing and multiple cleaning to obtain a flotation uranium concentrate I;

[0009] 4) the tailings obtained from the roughing are fed into flotation II, with lead nitrate and ferric sulfate as activators, isooctyl phosphate and alkyl hydroxamic acid as collectors, and one roughing, one scavenging and multiple cleaning processes are performed to obtain flotation uranium concentrate II;

[0010] 5) The tailings obtained by scavenging are subjected to magnetic separation to obtain magnetically separated uranium concentrate and magnetically separated tailings.

[0011] The gold contained in the uranium-containing gold leaching tailings of the present invention mainly exists in the form of elemental gold and is wrapped in gangue minerals, and the uranium minerals mainly include uranium stone, uraninite and crystalline uranium ore. The gold grade in the uranium-containing gold leaching tailings is 0.15-0.35g / t, and the uranium grade is about 0.018%.

[0012] In view of the low gold and uranium grades in the uranium-containing gold leaching tailings, and the fact that gold is mainly wrapped in gangue minerals, while uranium mainly exists in the form of uranium stone, uraninite and crystalline uranium ore, the technical solution of the present invention preferably adopts a physical method to recover gold. First, the gold wrapped in the gangue minerals is recovered in the form of coarse-grained tailings through classification treatment, and then the wrapped elemental gold is dissociated through fine grinding, and then the elemental gold is enriched through gravity separation by utilizing the characteristic of high specific gravity of elemental gold. The gold grade in this part of the gravity-selected gold concentrate is 9.87g / t, and the gold recovery rate is 24.87%. The gravity-selected tailings also contain some uranium and gold. Flotation with the fine-grained tailings can improve the recovery rate of uranium and gold. The uranium selection process is carried out in three steps. First, a special oxalic acid activator is used with butyl xanthate and N-substrate. The nitrobenzene amine combined collector is mainly used to achieve efficient flotation of uranium and gold coexisting with pyrite, and the gold grade in the obtained flotation uranium concentrate I is about 2.52g / t, and the recovery rate is about 47.07%; then, by adopting the lead nitrate and ferric sulfate combined activator, and the isooctyl phosphate and alkyl hydroxamic acid combined collector, the separation and enrichment of uranium minerals in the form of oxides are mainly achieved, and finally the flotation residue is separated from the weakly magnetic uranium minerals by strong magnetic separation, so as to further reduce the uranium content in the flotation tailings. The three-step uranium selection process can obtain a total uranium concentrate with a uranium grade of about 0.113% and a recovery rate of about 73.82%, while the flotation tailings yield reaches 86.65%, and the uranium grade is about 0.004%, which can meet the radioactivity exemption requirements.

[0013] As a preferred solution, the coarse-grained tailings have a particle size of +0.10 mm, and the fine-grained tailings have a particle size of -0.1 mm. The classification of uranium-containing gold leaching tailings mainly affects the enrichment of gold. A large number of experiments have shown that the -0.1 mm particle size contains almost no elemental gold, while the elemental gold is mainly wrapped in the +0.10 mm particle size by gangue minerals. Therefore, the use of a 0.1 mm screen for classification can achieve the initial enrichment of elemental gold.

[0014] As a preferred solution, the mass percentage of the coarse tailings is 65-95% after being finely ground to a particle size of -0.045 mm. The coarse tailings can be fully stripped of gangue minerals and release elemental gold after being finely ground to a preferred particle size range, which is beneficial to the subsequent re-selection and separation process of elemental gold.

[0015] As a preferred solution, the slurry is adjusted to a slurry mass percentage concentration of 10 to 50%.

[0016] As a preferred solution, the reagent system for roughing in the flotation I is: 100-3000 g / t of oxalic acid, 60-600 g / t of butyl xanthate, 40-400 g / t of N-nitrosophenylamine, and 20-100 g / t of frother; the frother is 2-octanol. The role of oxalic acid is mainly to activate the pyrite that is oxidized on the surface and covered by impurity ions, exposing active ferrous ions, which is conducive to the adsorption of the collector on the surface of pyrite. The combined use of butyl xanthate and N-nitrosophenylamine can exert the comprehensive collection effect of the collector on different sulfide-pyrites. The two act synergistically to form co-adsorption on the surface of pyrite, increase the cross-sectional width of the polar base, expand the coverage of the collector on the surface of pyrite, and improve floatability.

[0017] As a preferred solution, the reagent system for roughing in flotation II is: 100-1000 g / t of lead nitrate, 100-1000 g / t of ferric sulfate, 30-300 g / t of isooctyl phosphate, and 100-1000 g / t of alkyl hydroxamic acid. Lead nitrate and ferric sulfate mainly produce Pb by dissociation. 2+ and Fe 3+ Ions, these metal ions can be adsorbed on the surface of uranium oxide to form active sites, which can enhance the adsorption of collectors on the surface of uranium minerals. Isooctyl phosphate and alkyl hydroxamic acid are used in combination. The two contain different polar groups. The coordinated combination of the two polar groups shows a strong binding ability to the surface of uranium minerals after the activation and modification of lead ions and iron ions. It can not only act on the uranium ions exposed on the surface of uranium minerals, but also can bind to the Pb adsorbed on the surface of uranium minerals. 2+ and Fe 3+ Ions bind to make the surface of uranium minerals hydrophobic and improve the flotation recovery rate of uranium.

[0018] As a preferred solution, the reagent system for scavenging in the flotation II is: 10-100 g / t of isooctyl phosphate and 30-300 g / t of alkyl hydroxamic acid.

[0019] As a preferred solution, the magnetic field strength used in the magnetic separation is 0.8-2.0T.

[0020] As a preferred solution, the centrifugal concentrator is preferably a Nelson centrifugal concentrator.

[0021] The method for recovering uranium and gold from gold-extracting tailings of uranium-containing gold ore provided by the present invention comprises the following steps:

[0022] (1) Tailings classification:

[0023] The gold tailings from uranium-gold ore are separated into +0.10mm tailings and -0.10mm tailings using a sieve with a mesh size of 0.10mm. The gold in the tailings is distributed in the coarse-grained tailings and is wrapped by other gangue minerals, requiring further fine grinding and dissociation.

[0024] (2) Recovery of gold from +0.10 mm particle size tailings:

[0025] 1) The +0.10mm tailings are further finely ground to a particle size of -0.045mm, accounting for 65-95%;

[0026] 2) The tailings after fine grinding in 1) are separated by a Nelson centrifugal concentrator to obtain a gravity-separated gold concentrate and a gravity-separated gold tailings;

[0027] (3) Uranium recovery in flotation:

[0028] 1) combining the -0.10 mm particle size tailings obtained in (1) above with the gravity separation gold tailings to obtain uranium-containing tailings;

[0029] 2) adjusting the pulp concentration of the uranium tailings in 1) to an ore mass fraction of 10-50%, adding 100-3000 g / t of oxalic acid as an activator, stirring for 3-15 min at a speed of 1000-2500 r / min on a flotation machine, adding 60-600 g / t of butyl xanthate as a collector and 40-400 g / t of N-nitrosophenylhydroxylamine as a collector, stirring for 3-15 min at a speed of 1000-2500 r / min on a flotation machine, adding 20-100 g / t of sec-octanol as a frother, stirring for 3-15 min at a speed of 1000-2500 r / min on a flotation machine, aerating and roughing after the mineral and the reagent are fully contacted, to obtain roughing uranium concentrate I and roughing uranium tailings I;

[0030] 3) The roughing uranium concentrate I obtained in the above 2) is subjected to multiple concentrations without adding reagents during the concentration process until the ideal flotation index is reached to obtain the flotation uranium concentrate I, and the flotation tailings are returned to the previous flotation stage in sequence;

[0031] 4) adding activator lead nitrate 100-1000 g / t and ferric sulfate 100-1000 g / t to the rough uranium tailings I obtained in 2) above, stirring for 3-15 min at a speed of 1000-2500 r / min on a flotation machine, adding collector isooctyl phosphate 30-300 g / t and alkyl hydroxamic acid 100-1000 g / t, stirring for 3-15 min at a speed of 1000-2500 r / min on a flotation machine, and aerating and roughing after the mineral and the reagent are fully contacted to obtain rough uranium concentrate II and rough uranium tailings II;

[0032] 5) adding 10-100 g / t of isooctyl phosphate and 30-300 g / t of alkyl hydroxamic acid as collector to the rough uranium tailings II obtained in 4) above, stirring the flotation machine at a speed of 1000-2500 r / min for 3-15 min, aerating and scavenging the ore after the ore and the reagent are fully contacted, and obtaining scavenged uranium concentrate and scavenged uranium tailings;

[0033] 6) The roughing uranium concentrate II obtained in 4) and the scavenging uranium concentrate obtained in 5) are combined and subjected to multiple concentrations without adding reagents during the concentration process until the ideal flotation index is reached to obtain the flotation uranium concentrate II, and the flotation tailings are returned to the previous flotation stage in sequence.

[0034] (4) Strong magnetic recovery of uranium minerals

[0035] The scavenged uranium tailings are subjected to magnetic separation by a strong magnetic separator under the condition of a magnetic field strength of 0.8 to 2.0 T to recover weakly magnetic uranium minerals, thereby obtaining magnetically separated uranium concentrate and tailings.

[0036] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0037] The technical solution of the present invention aims at the characteristics that the gold and uranium grades in the uranium-containing gold leaching tailings are low, the gold is mainly wrapped in the gangue minerals in the form of elemental gold, and the uranium is mainly present in the form of uranium stone, uraninite and crystalline uranium ore, etc., and adopts the technical means of combining classification, fine grinding, gravity separation, flotation and gravity separation to realize the enrichment and separation of gold and uranium in the uranium-containing gold leaching tailings, so as to achieve the resource recovery of valuable metals in the uranium-containing gold leaching tailings and reduce the radioactive pollution to the environment. The specific ore dressing process of the present invention adopts the method of preferentially recovering gold and then recovering uranium. The preliminary enrichment of gold is firstly achieved through classification treatment. Based on the characteristic that the gold remaining in the gold leaching tailings is mainly wrapped by gangue minerals, the gold can be enriched in the coarse-grained tailings by controlling the classification particle size. Then, the gangue minerals are stripped by fine grinding and re-selection is performed to achieve the enrichment of gold. The gold grade in this part of the re-selected gold concentrate is 9.87 g / t, and the gold recovery rate is 24.87%. The re-selected tailings also contain part of uranium and gold. The flotation with the fine-grained tailings can improve the recovery rate of uranium and gold. The uranium selection process is carried out in three steps. First, a special oxalic acid activator is used to combine with butyl xanthate and N-nitrosophenylhydroxylamine to form a uranium concentrate. The combined collector is mainly used to realize the efficient flotation of pyrite-symbiotic uranium ore and gold ore. The gold grade in the obtained flotation uranium concentrate I is 2.52g / t, and the recovery rate is 47.07%; then, by adopting the combined activator of lead nitrate and ferric sulfate, and the combined collector of isooctyl phosphate and alkyl hydroxamic acid, the separation and enrichment of uranium minerals in the form of oxides are mainly realized. Finally, the flotation residue is separated from weakly magnetic uranium minerals by strong magnetic separation, so as to further reduce the uranium content in the flotation tailings. The three-step uranium separation process can obtain a total uranium concentrate with a uranium grade of 0.113% and a recovery rate of 73.82%, while the flotation tailings yield is 86.65% and the uranium grade is 0.004%, which can meet the radioactivity exemption requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a process flow chart for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines. DETAILED DESCRIPTION

[0039] The following specific examples are intended to further illustrate the present invention rather than to limit the scope of protection of the claims.

[0040] Example 1

[0041] The gold leaching tailings are mainly composed of quartz, pyrophyllite, chlorite, muscovite, gypsum, iron oxide, pyrite, feldspar, rutile, etc. Gold mainly exists in the form of elemental gold, which is wrapped by other gangue minerals. The uranium minerals mainly include uraninite, uraninite and crystalline uraninite. The gold grade is 0.25g / t and the uranium grade is 0.018%.

[0042] (1) Take three portions of tailings, numbered A, B, and C, and separate them into +0.10 mm tailings and -0.10 mm tailings using a sieve with a mesh size of 0.10 mm;

[0043] (2) further grinding the +0.10 mm tailings in A, B, and C to a particle size of -0.045 mm, which accounts for 70%, and separating them using a Nelson centrifugal concentrator to obtain a gravity-separated gold concentrate and a gravity-separated gold tailings;

[0044] (3) The tailings of -0.10 mm particle size in A, B and C are combined with the gold tailings of gravity separation, and the pulp concentration is adjusted to 20% of the mass fraction of the ore. Activating agents oxalic acid 1500 g / t, 1500 g / t and 0 g / t are added to A, B and C respectively, and the flotation machine is stirred at a speed of 1500 r / min for 15 min. Collecting agents butyl xanthate 200 g / t and N-nitrosophenylhydroxylamine 150 g / t are added to A, B and C respectively, and the flotation machine is stirred at a speed of 1500 r / min for 15 min. A, B and C are added with a foaming agent 2-octanol 50 g / t, and the flotation machine is stirred at a speed of 1500 r / min for 15 min. After the minerals are fully contacted with the reagents, aeration is carried out for roughing, and roughing uranium concentrate I and roughing uranium tailings I are obtained;

[0045] (4) adding 500 g / t of lead nitrate and 500 g / t of ferric sulfate as activators to the rough uranium tailings I of A, adding 1000 g / t of lead nitrate and 0 g / t of ferric sulfate as activators to the rough uranium tailings I of B, adding 0 g / t of lead nitrate and 1000 g / t of ferric sulfate as activators to the rough uranium tailings I of C, stirring the mixture for 15 min at a speed of 1500 r / min on a flotation machine, adding 100 g / t of isooctyl phosphate and 500 g / t of alkyl hydroxamic acid as collectors to A, B and C respectively, stirring the mixture for 15 min at a speed of 1500 r / min on a flotation machine, and aerating and roughing after the minerals are fully contacted with the reagents to obtain a rough uranium concentrate II and a rough uranium tailings II;

[0046] (5) Collectors of isooctyl phosphate 30 g / t and alkyl hydroxamic acid 100 g / t were added to the rough uranium tailings II of A, B and C respectively, and the flotation machine was stirred at a speed of 1500 r / min for 15 min. After the ore and the reagent were fully contacted, aeration was performed to obtain scavenged uranium concentrate and scavenged uranium tailings;

[0047] (6) The A, B, and C scavenged uranium tailings are subjected to magnetic separation using a high-intensity magnetic separator under a magnetic field strength of 1.4 T to recover weakly magnetic uranium minerals, thereby obtaining magnetically separated uranium concentrates and tailings.

[0048] The test results are shown in Table 1.

[0049] Table 1 Experimental results of Example 1

[0050]

[0051]

[0052] Example 2

[0053] The gold leaching tailings are mainly composed of quartz, pyrophyllite, chlorite, muscovite, gypsum, iron oxide, pyrite, feldspar, rutile, etc. Gold mainly exists in the form of elemental gold, which is wrapped by other gangue minerals. The uranium minerals mainly include uraninite, uraninite and crystalline uraninite. The gold grade is 0.25g / t and the uranium grade is 0.018%.

[0054] (1) Take three portions of tailings, numbered A, B, and C, and separate them into +0.10 mm tailings and -0.10 mm tailings using a sieve with a mesh size of 0.10 mm;

[0055] (2) further grinding the +0.10 mm tailings in A, B, and C to a particle size of -0.045 mm, which accounts for 75%, and separating them using a Nelson centrifugal concentrator to obtain a gravity-separated gold concentrate and a gravity-separated gold tailings;

[0056] (3) The -0.10 mm tailings in A, B and C were combined with the re-selected gold tailings, and the pulp concentration was adjusted to 25% of the ore mass fraction. 1200 g / t of oxalic acid as an activator was added to A, B and C respectively. The flotation machine was stirred at a speed of 2500 r / min for 3 min. 300 g / t of butyl xanthate and 100 g / t of N-nitrosophenylamine as collectors were added to A, and 400 g / t of butyl xanthate as collector was added to B. , 0 g / t of N-nitrosophenylhydroxylamine, 0 g / t of butyl xanthate as a collector and 400 g / t of N-nitrosophenylhydroxylamine as a collector are added to C, and the flotation machine is stirred at a speed of 2500 r / min for 3 min, 35 g / t of octanol as a frother are added to A, B and C respectively, and the flotation machine is stirred at a speed of 2500 r / min for 3 min, and the ore is aerated and roughly selected after sufficient contact with the reagent to obtain a roughing uranium concentrate I and a roughing uranium tailings I;

[0057] (4) 800 g / t of lead nitrate and 400 g / t of ferric sulfate as activators were added to the rough uranium tailings I of A, B and C respectively, and stirred for 3 min at a speed of 2500 r / min on a flotation machine; 80 g / t of isooctyl phosphate and 550 g / t of alkyl hydroxamic acid as collectors were added to A, B and C respectively, and stirred for 3 min at a speed of 2500 r / min on a flotation machine; after the minerals were fully contacted with the reagents, aeration was performed for roughing, and rough uranium concentrate II and rough uranium tailings II were obtained;

[0058] (5) 20 g / t of isooctyl phosphate and 120 g / t of alkyl hydroxamic acid are added to the A, B and C rough uranium tailings II, respectively, and the flotation machine is stirred at a speed of 2500 r / min for 3 min. After the ore and the reagent are fully contacted, aeration is performed to obtain scavenged uranium concentrate and scavenged uranium tailings;

[0059] (6) The A, B, and C scavenged uranium tailings are subjected to magnetic separation using a high-intensity magnetic separator under a magnetic field strength of 1.8 T to recover weakly magnetic uranium minerals, thereby obtaining magnetically separated uranium concentrates and tailings.

[0060] The test results are shown in Table 2.

[0061] Table 2 Experimental results of Example 2

[0062]

[0063]

[0064] Example 3

[0065] The gold leaching tailings are mainly composed of quartz, pyrophyllite, chlorite, muscovite, gypsum, iron oxide, pyrite, feldspar, rutile, etc. Gold mainly exists in the form of elemental gold, which is wrapped by other gangue minerals. The uranium minerals mainly include uraninite, uraninite and crystalline uraninite. The gold grade is 0.25g / t and the uranium grade is 0.018%.

[0066] (1) Take three portions of tailings, numbered A, B, and C, and separate them into +0.10 mm tailings and -0.10 mm tailings using a sieve with a mesh size of 0.10 mm;

[0067] (2) The +0.10 mm tailings in A, B, and C are further finely ground to a particle size of -0.045 mm, accounting for 85%, and are separated by a Nelson centrifugal concentrator to obtain a gravity-separated gold concentrate and a gravity-separated gold tailings;

[0068] (3) The tailings of -0.10 mm particle size in A, B and C were combined with the gold tailings of gravity separation, and the pulp concentration was adjusted to 35% of the mass fraction of the ore. 1200 g / t of oxalic acid as an activator was added to A, B and C respectively, and the flotation machine was stirred at a speed of 2500 r / min for 3 min. 350 g / t of butyl xanthate and 150 g / t of N-nitrosophenylhydroxylamine as collectors were added to A, B and C respectively, and the flotation machine was stirred at a speed of 2000 r / min for 10 min. 45 g / t of sec-octanol as a frother was added to A, B and C respectively, and the flotation machine was stirred at a speed of 2000 r / min for 10 min. After the minerals were fully contacted with the reagents, aeration was carried out for roughing, and roughing uranium concentrate I and roughing uranium tailings I were obtained;

[0069] (4) The A, B, and C rougher uranium concentrates I are each flotated once, and the flotation tailings are returned to the previous flotation stage to obtain flotation uranium concentrate I.

[0070] (5) 700 g / t of lead nitrate and 500 g / t of ferric sulfate as activators are added to rough uranium tailings I of A, B and C respectively, and stirred for 10 min at a flotation machine at a speed of 2000 r / min, 100 g / t of isooctyl phosphate and 500 g / t of alkyl hydroxamic acid as collectors are added to A, 600 g / t of isooctyl phosphate and 0 g / t of alkyl hydroxamic acid as collectors are added to B, and 0 g / t of isooctyl phosphate and 600 g / t of alkyl hydroxamic acid as collectors are added to C, and stirred for 10 min at a flotation machine at a speed of 2000 r / min, and the ore is fully contacted with the reagents and then aerated and roughly separated, to obtain rough uranium concentrate II and rough uranium tailings II;

[0071] (6) adding 20 g / t of isooctyl phosphate and 120 g / t of alkyl hydroxamic acid as collectors to the rough uranium tailings II of A, B and C respectively, stirring the flotation machine at a speed of 2500 r / min for 3 min, and aerating and scavenging the ore after the ore and the reagent are fully contacted to obtain scavenged uranium concentrate and scavenged uranium tailings;

[0072] (7) The roughing uranium concentrate II and the scavenging uranium concentrate obtained from A, B, and C are combined, each of which is flotated once, and the flotation tailings are returned to the previous flotation stage to obtain flotation uranium concentrate II.

[0073] (8) The A, B, and C scavenged uranium tailings are subjected to magnetic separation using a high-intensity magnetic separator under a magnetic field strength of 2.2 T to recover weakly magnetic uranium minerals, thereby obtaining magnetically separated uranium concentrates and tailings.

[0074] The test results are shown in Table 3.

[0075] Table 3 Experimental results of Example 3

[0076]

[0077]

[0078] Example 4

[0079] The gold leaching tailings are mainly composed of quartz, pyrophyllite, chlorite, muscovite, gypsum, iron oxide, pyrite, feldspar, rutile, etc. Gold mainly exists in the form of elemental gold, which is wrapped by other gangue minerals. The uranium minerals mainly include uraninite, uraninite and crystalline uraninite. The gold grade is 0.25g / t and the uranium grade is 0.018%.

[0080] (1) The tailings are separated into +0.10 mm and -0.10 mm grades using a sieve with a mesh size of 0.10 mm;

[0081] (2) further grinding the tailings with a particle size of +0.10 mm to a particle size of -0.045 mm, which accounts for 80%, and separating them using a Nelson centrifugal concentrator to obtain a re-selected gold concentrate and a re-selected gold tailings;

[0082] (3) The -0.10 mm particle size tailings and the gravity separation gold tailings are combined, and the pulp concentration is adjusted to 30% of the ore mass fraction, and 1500 g / t of oxalic acid as an activator is added, and the flotation machine is stirred at a speed of 2000 r / min for 5 minutes, and 250 g / t of butyl xanthate and 250 g / t of N-nitrosophenylhydroxylamine as collectors are added, and the flotation machine is stirred at a speed of 2000 r / min for 5 minutes, and 60 g / t of octanol as a frother is added, and the flotation machine is stirred at a speed of 2000 r / min for 5 minutes. After the minerals are fully contacted with the reagents, aeration is carried out for roughing, and roughing uranium concentrate I and roughing uranium tailings I are obtained;

[0083] (4) The rougher uranium concentrate I is refined once, and the refined tailings are returned to the previous flotation stage to obtain the flotation uranium concentrate I.

[0084] (5) adding 600 g / t of lead nitrate and 400 g / t of ferric sulfate as activators to the rough uranium tailings I, stirring the mixture at a speed of 2000 r / min for 5 min on a flotation machine, adding 100 g / t of isooctyl phosphate and 600 g / t of alkyl hydroxamic acid as collectors, stirring the mixture at a speed of 2000 r / min for 5 min on a flotation machine, and aerating and roughing the mixture after the ore and the reagents are fully contacted to obtain a rough uranium concentrate II and a rough uranium tailings II;

[0085] (6) adding 20 g / t of isooctyl phosphate and 150 g / t of alkyl hydroxamic acid as collectors to the rough uranium tailings II, stirring the flotation machine at a speed of 2000 r / min for 5 min, and aerating and scavenging the ore after the ore and the reagent are fully contacted to obtain scavenged uranium concentrate and scavenged uranium tailings;

[0086] (7) The roughing uranium concentrate II and the scavenging uranium concentrate are combined, and the concentrated uranium concentrate is concentrated once, and the concentrated tailings are returned to the previous flotation to obtain the flotation uranium concentrate II.

[0087] (8) The scavenged uranium tailings are subjected to magnetic separation by a high-intensity magnetic separator under a magnetic field strength of 2.0 T to recover weakly magnetic uranium minerals, thereby obtaining magnetically separated uranium concentrates and tailings.

[0088] The test results are shown in Table 4-1, and the tailings radioactivity test results are shown in Table 4-2

[0089] Table 4-1 Experimental results of Example 4

[0090]

[0091] Table 4-2 Tailings radioactivity test results Bq / Kg

[0092] Test items <![CDATA[ 238 In]]> <![CDATA[ 226 Day]]> <![CDATA[ 232 Th]]> <![CDATA[ 40 K]]> Tailings 423 578 375 2682 National Standard (GB20664-2006) 1000 1000 1000 10000 .

Claims

1. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines, characterized in that: The following steps are involved: 1) Screening and grading the uranium-containing gold leaching tailings to obtain coarse-grained tailings and fine-grained tailings; 2) grinding the coarse tailings and then re-selecting them using a centrifugal concentrator to obtain re-selected gold concentrate and re-selected gold tailings; 3) The fine-grained tailings and the gravity-selected gold tailings are combined and slurried, and then enter flotation I, using oxalic acid as an activator, butyl xanthate and N-nitrosophenylamine as collectors, and adding a frother, and performing a roughing and multiple cleaning to obtain a flotation uranium concentrate I; 4) The tailings obtained from the roughing are fed into flotation II, with lead nitrate and ferric sulfate as activators, isooctyl phosphate and alkyl hydroxamic acid as collectors, and one roughing, one scavenging and multiple cleaning processes are performed to obtain flotation uranium concentrate II; 5) The tailings obtained by scavenging are sent to magnetic separation to obtain magnetically separated uranium concentrate and magnetically separated tailings.

2. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines according to claim 1, characterized in that: The particle size of the coarse-grained tailings is +0.10 mm; the particle size of the fine-grained tailings is -0.1 mm.

3. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines according to claim 1 or 2, characterized in that: The mass percentage of the coarse-grained tailings finely ground to a particle size of -0.045 mm accounts for 65-95%.

4. A method for recovering uranium and gold from gold-extracting tailings of uranium-containing gold ore according to claim 1, characterized in that: The slurry adjustment is performed to adjust the slurry mass percentage concentration to 10-50%.

5. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines according to claim 1, 2 or 4, characterized in that: The reagent system for roughing in the flotation I is: Oxalic acid 100~3000g / t, Butyl xanthate 60~600g / t, N-nitrosophenylamine 40~400g / t, Foaming agent 20~100g / t; The foaming agent is octanol.

6. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines according to claim 1, 2 or 4, characterized in that: The reagent system for roughing in flotation II is: Lead nitrate 100~1000g / t, Ferrous sulfate 100~1000g / t, Isooctyl phosphate 30~300g / t, Alkyl hydroxamic acid 100~1000g / t.

7. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines according to claim 1, 2 or 4, characterized in that: The reagent system for scavenging in the flotation II is: 10-100 g / t of isooctyl phosphate and 30-300 g / t of alkyl hydroxamic acid.

8. A method for recovering uranium and gold from gold-extracting tailings from uranium-containing gold mines according to claim 1, characterized in that: The magnetic field strength used in the magnetic separation is 0.8~2.0T.

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