Method for reinforced flotation recovery of low-grade beryl in spodumene tailings

Abstract

The invention discloses a method for reinforced flotation recovery of low-grade beryl in spodumene tailings, and belongs to the technical field of mineral separation. The method comprises the steps that after spodumene tailings are subjected to size mixing, amine and fatty acid serve as a combined collecting agent, flotation I is conducted, and mica concentrate and tailings I are obtained; after size mixing is conducted on the tailings I, phosphate serves as an inhibitor, a metal-hydroximic acid organic complex and fatty acid serve as a combined collecting agent, flotation II is conducted, and beryl rough concentrate and tailings II are obtained; and after regrinding treatment is conducted on the beryl rough concentrate, size mixing is conducted, phosphate and EDTA serve as a combined inhibitor, flotation III is conducted, and beryl concentrate and tailings III are obtained. By means of the method, the beryl concentrate with the BeO grade being 6.12% and the recovery rate being 45.86% can be obtained, efficient recovery of low-grade beryl resources in the spodumene tailings is effectively achieved, and great economic benefits are achieved.

Description

Technical Field

[0001] This invention relates to a method for treating spodumene tailings, and more particularly to a method for enhanced flotation recovery of low-grade beryl from spodumene tailings. Specifically, it involves sequentially passing spodumene tailings through reverse flotation to remove mica, beryl flotation pre-enrichment, and regrinding and re-selection of the beryl rough concentrate to obtain beryl concentrate product, thereby achieving efficient recovery of low-grade beryl resources from spodumene tailings. This method belongs to the field of mineral processing technology. Background Technology

[0002] Beryllium is widely used in aerospace, defense, nuclear energy, and advanced electronics, and is irreplaceable. However, currently developed beryllium resources are mostly low-grade and occur as associated minerals. Meanwhile, with the rapid development of the new energy industry, global demand for lithium resources has surged, leading to massive amounts of flotation tailings from the large-scale development of pegmatite-type spodumene mines. These tailings often contain highly valuable beryllium resources, primarily in the form of beryl. However, due to limitations in existing industrial recovery technologies, the vast majority of these valuable beryllium resources have not been effectively recovered, resulting in serious resource waste and potential environmental risks. The current beneficiation industry for pegmatite-type spodumene mines generally uses a "preferential flotation of spodumene" (i.e., "beryllium-suppressed lithium flotation") process to produce lithium concentrate. This process uses a large amount of depressants under strongly alkaline conditions (pH 10-12) to strongly suppress beryl and other silicate gangues, ensuring the grade of the lithium concentrate. This process results in severe "contamination" of the beryl surface, rendering the beryl in the tailings no longer in a naturally floatable state, and affecting its surface active sites (Al). 3+ Be 2+ The beryl is completely obscured, highly hydrophilic, and loses its inherent floatability. Therefore, applying the classic "activated flotation" technique, traditionally used for primary beryl minerals, directly to this type of tailings yields extremely poor results. This is because the passivation layer on the beryl surface in the tailings makes it difficult for the reagents to interact, resulting in low selectivity and unsatisfactory enrichment. Furthermore, beryl has similar surface properties to gangue minerals such as spodumene, feldspar, and quartz, placing extremely high demands on reagent and process design to achieve highly selective separation in complex tailings systems. Summary of the Invention

[0003] To address the significant waste caused by the ineffective recovery of low-grade beryl from spodumene tailings in existing technologies, this invention aims to provide a method for enhanced flotation recovery of low-grade beryl from spodumene tailings. This method employs a process flow of "reverse flotation for impurity removal" + "beryl pre-enrichment" + "beryl rough concentrate regrinding and re-selection for quality improvement," which enables the gradual enrichment of beryl and ultimately achieves high-grade beryl with a high recovery rate, truly realizing the efficient recovery of low-grade beryl resources from spodumene tailings.

[0004] To achieve the above-mentioned technical objectives, the present invention provides a method for enhanced flotation recovery of low-grade beryl from spodumene tailings, comprising the following steps:

[0005] 1) After slurry preparation, amines and fatty acids are used as a combined collector for spodumene tailings. Flotation I is performed to obtain mica concentrate and tailings I;

[0006] 2) After tailings I is slurry-treated, phosphate is used as an inhibitor. Metal-hydroxyoxime acid organic complexes and fatty acids as combined collectors Flotation II was performed to obtain beryl crude concentrate and tailings II.

[0007] 3) After regrinding the beryl concentrate, the slurry is prepared using phosphate and EDTA as a combined inhibitor. Flotation III was carried out to obtain beryl concentrate and tailings III.

[0008] The method for recovering low-grade beryl from spodumene tailings by flotation provided by this invention is mainly based on the mineral composition characteristics of spodumene tailings, which are dominated by beryl and contain a low content of spodumene as well as gangue minerals such as mica, feldspar, and clay. Addressing the technical challenge that beryl and most gangue minerals are silicate minerals with highly similar crystal structures and surface physicochemical properties, making them difficult to separate, this invention employs a beneficiation process of reverse flotation to remove mica from spodumene tailings, beryl pre-enrichment, and regrinding and re-selection of the beryl concentrate to improve its quality. This ultimately yields a high-grade beryl concentrate product, truly achieving efficient recovery of low-grade beryl resources from spodumene tailings. More specifically, this invention is based on the high similarity of the surface chemical properties of beryl and some of its gangue minerals, while there is a difference in floatability between beryl and mica. A combined cationic and anionic collector, formed by amines and fatty acids, can be used to pre-remove mica through reverse flotation. Phosphate is then used as an inhibitor to effectively suppress the silicate gangue minerals. Simultaneously, a metal-hydroxyoxime acid organic complex and a fatty acid collector are used to enhance the collection effect on beryl, thereby widening the floatability gap between beryl and its gangue minerals. This achieves enhanced flotation of beryl, yielding a rough beryl concentrate, thus pre-enriching beryl. Based on this, the rough beryl concentrate is regrinded. On the one hand, this allows for sufficient monomer liberation of beryl; on the other hand, grinding "cleans" the surface of the gangue minerals, removing the reagents from the surface. This facilitates the subsequent highly selective modification of the gangue mineral surface by phosphate and EDTA, achieving better inhibition and thus achieving efficient separation to obtain the beryl concentrate product.

[0009] As a preferred embodiment, the spodumene tailings contain beryllium minerals, including beryl. More specifically, the total mass content of gangue minerals such as feldspar, mica, and quartz in the spodumene tailings is ≥85%, the mass content of BeO is ≥0.03%, and the mass content of mica is 30-40%.

[0010] As a preferred embodiment, the spodumene tailings, after slurry preparation, have a slurry concentration adjusted to 45-50 wt.% and a pH adjusted to 9.5-10.5. The pH adjustment utilizes a composite alkali composed of caustic soda and soda ash in a mass ratio of (1-3):1. A further preferred pH adjustment is to 9.8-10.2. The composite alkali is further preferably formed by mixing caustic soda and soda ash in a mass ratio of (1-2):1. The soda ash in the composite alkali primarily acts as a pH buffer to maintain the stability of the slurry pH and effectively disperses negatively charged sludge by compressing the double electric layer. The caustic soda primarily functions to adjust the pH, bringing the slurry to a slightly alkaline environment, which helps eliminate the influence of some unavoidable metal ions.

[0011] As a preferred embodiment, the combined collector It is composed of amines and fatty acids in a mass ratio of (1~2):1. This invention relates to a combined collector. Composed of amines and fatty acids in an appropriate mass ratio, with amines being cationic collectors and fatty acids being anionic collectors, this combination offers a highly efficient synergistic effect in mica flotation. Compared to the poor selectivity resulting from using amine collectors alone, and the weak collection capacity and low recovery rate resulting from using fatty acid collectors alone, this combination utilizes both electrostatic attraction and chemical bonding to enhance the adsorption effect of the combined collectors on the mica surface, thereby strengthening the efficient flotation of mica and overcoming the defects of single anionic or cationic collectors. This significantly improves the flotation efficiency and selectivity of mica.

[0012] As a preferred embodiment, the amines include polyetheramines, C8~C999 amines, etc. 13 Alkyl ether amines, ether diamines, C8~C 13 At least one of the fatty amines. Specific examples include dodecylamine and cocoylamine, which are conventional amine collectors in the prior art.

[0013] As a preferred embodiment, the fatty acids include at least one of sodium oleate, linoleic acid, naphthenic acid, talc oil, lauric acid, linolenic acid, palmitic acid, stearic acid, ricinoleic acid, and 731 oxidized paraffin soap.

[0014] As a preferred embodiment, flotation I includes one roughing stage and one scavenging stage. As a more preferred embodiment, the reagent regime for the roughing stage is a combination of collectors. The dosage relative to the raw ore is 600-800 g / t. As a preferred option, the scavenging reagent system is: a combination collector. The amount of beryllium used is halved compared to that used in roughing. Under optimized flotation conditions, mica gangue minerals can be efficiently removed to achieve preliminary enrichment of beryl, and the residual amount of beryllium minerals in the resulting mica concentrate is low.

[0015] As a preferred embodiment, the tailings I are slurry pre-mixed to a pH of 9.5–10.0. Metal-hydroxyoxime acid organic complexes are highly sensitive to pH conditions; within different pH ranges, the three-dimensional spatial structures assembled by these complexes differ, exhibiting varying collecting abilities and selectivity. Within the preferred pH range, the collection of beryl by metal-hydroxyoxime acid organic complexes is advantageous.

[0016] As a preferred embodiment, the combined collector The metal-hydroxyoxime acid organic complexes and fatty acids are measured at a mass ratio of (1~4):1. The combined use of fatty acids and metal-hydroxyoxime acid complexes offers both good collecting ability and selectivity. Through their efficient synergistic effect, they overcome the shortcomings of relatively weak collecting ability and insufficient recovery rate of single metal-hydroxyoxime acid organic complexes, as well as the poor selectivity of single fatty acids. This significantly improves flotation efficiency and selectivity, enhancing the effective and simultaneous recovery of the target minerals.

[0017] As a preferred embodiment, the metal-hydroxyoxime acid organic complex is formed by the coordination assembly of a divalent or higher metal ion and a hydroxamic acid organic ligand in a molar ratio of 1:(1~12). As a more preferred embodiment, the divalent or higher metal ion includes Ca... 2+ Mg 2+ Zn 2+ Fe 2+ Pb 2+ Cu 2+ Mn 2+ Fe 3+ Or Al 3+ At least one of the following. The divalent or higher-valent metal ion is further preferably Ca... 2+ or Fe 3+ As a preferred embodiment, the hydroxamic acid organic ligands include benzohydroxyxamic acid, salicylic acid, and C6-C6 hydroxyxamic acid. 12 At least one of the alkyl hydroxyoxime acids. C6~C 12 The alkyl hydroxamic acid can be a straight-chain alkyl group or a branched alkyl hydroxamic acid. Metal-hydroxamic acid organic complexes have a targeted adsorption effect on the Al-O active sites on the surface of beryl minerals, thereby achieving the harvesting of beryl.

[0018] As a preferred embodiment, the inhibitor It is a phosphate. Inhibitor. It is mainly used to suppress silicate minerals. Phosphates can also act as dispersants, increasing the steric hindrance effect and electrostatic repulsion between particles, which helps to reduce the aggregation of mineral particles.

[0019] As a preferred embodiment, the phosphate includes at least one of sodium metaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate. These phosphates are common inorganic phosphates.

[0020] As a preferred embodiment, flotation II includes one roughing stage, one scavenging stage, and three cleaning stages. As a more preferred embodiment, the reagent regime for the roughing stage is a combination of collectors. relative tailings The addition amount is 400~600g / t; inhibitor relative tailings The addition amount is 100~120g / t. As a preferred embodiment, the selected formulation is: inhibitor... The dosage follows a gradually decreasing principle. As a preferred option, the scavenging reagent system is: a combination of collectors. The dosage is halved compared to the roughing process. Flotation II of this invention is a pre-enrichment flotation of beryl. It uses a combination of fatty acid and metal-hydroxyoxime acid complex collectors, which have strong collecting ability and high selectivity for beryl. Combined with a phosphate inhibitor that has a strong inhibitory effect on silicate minerals, it can improve the separation efficiency of beryl from its gangue minerals.

[0021] As a preferred embodiment, the combined inhibitor It is composed of EDTA and phosphate in a mass ratio of 3-4:1-2. EDTA, as a strong complexing agent, strongly complexes and dissolves Al on the surface of gangue. 3+ Deeply stripped Al from the surface of gangue and the collector 3+ Active sites. After EDTA treatment, the aluminosilicate surface becomes dominated by an inert Si-O-Si structure, greatly reducing its reactivity with collectors. However, for the more dense and stable beryl, its surface Al... 3+ and Be 2+ Under the same conditions, it is not easily completely complexed and dissolved by EDTA. Therefore, after EDTA treatment, a considerable portion of the active Al2+ remains on the surface of beryl. 3+ and Be 2+The EDTA pretreatment creates more "fresh," unsaturated bonding sites on the aluminosilicate gangue surface, enhancing its ability to react with the collector. Phosphate is then adsorbed in large quantities and tightly onto the EDTA-etched gangue surface, forming a complete and dense hydrophilic phosphate polymer film. This film, through steric hindrance and strong negative electrostatic repulsion, effectively blocks the collector from approaching the gangue surface. This achieves a double attack on the gangue surface—"chemical etching (EDTA) + hydrophilic shielding (phosphate)"—completely suppressing its buoyancy. However, for beryl, since the surface is not deeply damaged by EDTA, its phosphate adsorption capacity is weaker, resulting in a smaller adsorption amount. Therefore, the phosphate coating on the beryl surface may be incomplete and sparse, failing to completely shield the active sites (Al2O3) on its surface. 3+ Be 2+ Therefore, this combination of inhibitors only provides "light cleaning (EDTA) + slight modification (phosphate)" for beryl, thus preserving its floatability and achieving efficient flotation separation.

[0022] As a preferred embodiment, the regrinding process controls the mass percentage of particles with a particle size of -0.074 mm to be no less than 90%.

[0023] As a preferred embodiment, flotation III includes one roughing stage and two cleaning stages. As a more preferred embodiment, the roughing reagent regimen is a combination of inhibitors. The dosage of beryl concentrate is 120-180 g / t. As a preferred embodiment, the pulp concentration in the roughing process is 25-35 wt%, and the pH is maintained between 9.5 and 10.0. Sodium carbonate is used to adjust the pH of the pulp during the conditioning process; under these preferred pH conditions, beryl flotation is more favorable. As a preferred embodiment, the reagent system for the fine-graining process is a combination of inhibitors. The dosage is halved compared to the roughing process. As a preferred option, both the scavenging and ore concentrates are sequentially returned to the previous operation. The beryl rough concentrate is treated with a combination of phosphate and EDTA inhibitors to achieve targeted inhibition of its aluminosilicate gangue, thereby achieving efficient flotation separation of beryl and obtaining beryl concentrate product. With the optimized flotation reagent system, a beryllium concentrate with a BeO grade of 6.12% and a recovery rate of 45.86% can be obtained.

[0024] As a preferred embodiment, the phosphate includes at least one of sodium metaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate.

[0025] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0026] (1) The present invention adopts the process of “reverse flotation to remove mica + beryl pre-enrichment + beryl rough concentrate regrinding and re-selection to improve quality”, which can obtain high-grade beryl concentrate products with high recovery rate.

[0027] (2) The technical solution of this invention applies the concept of "re-grinding and re-selection of rough concentrate" to the flotation recovery of low-grade beryl in spodumene tailings. For the regrinding treatment of beryl rough concentrate, on the one hand, it can enable beryl to achieve sufficient monomer liberation, which is conducive to further flotation to improve the grade of beryl. On the other hand, grinding can achieve "cleaning of gangue mineral surface", and the gangue mineral surface can be de-treated, which is conducive to improving the adsorption effect of subsequent phosphate and EDTA on the gangue mineral surface, thereby achieving further upgrading of beryl to obtain high-grade beryl concentrate product. Compared with the conventional direct flotation process of beryl, the technical solution of this invention ensures a high enrichment ratio of beryllium resources while achieving a recovery rate of nearly 50%, and can obtain a beryl concentrate product with a BeO grade of 6.12% and a recovery rate of 45.86%.

[0028] (3) The technical solution of the present invention adopts a flotation reagent system of "metal-hydroxyoxime complex + fatty acid" for the efficient and enhanced flotation of beryl in spodumene tailings. It prioritizes the flotation and recovery of beryl minerals to obtain beryl rough concentrate. The beryl rough concentrate is then further refined by using a combination of highly selective phosphate and EDTA inhibitors after regrinding, thereby achieving efficient separation to obtain beryl concentrate product.

[0029] (4) Compared with the conventional reverse flotation of beryl using anionic collectors under acidic conditions, which involves equipment requirements and environmental challenges due to the use of hydrofluoric acid, the positive flotation of beryl using cationic collectors under alkaline conditions suffers from the drawbacks of sensitivity to slime and often resulting in low recovery rates. The technical solution of this invention adopts a combined collector flotation technology + rough concentrate regrinding process to achieve efficient and enhanced recovery of low-grade beryl. The entire flotation process is maintained under alkaline / weakly alkaline conditions, with low reagent consumption and low cost.

[0030] In summary, the technical solution of this invention has the characteristics of short process, simple operation and strong adaptability. It truly realizes the efficient recovery of low-grade beryl from spodumene tailings, which is of great significance for ensuring the sustainable development of the beryllium smelting industry and ensuring the security of key beryllium mineral resources, and is conducive to large-scale promotion and use. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the present invention.

[0032] Figure 2 The process flow diagram is for comparison with Example 1. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the claims of the present invention.

[0034] This study investigated an enhanced flotation method for recovering low-grade beryl from spodumene tailings obtained from a spodumene concentrator in Sichuan Province. The sample contained approximately 0.03% BeO, indicating high recovery value. Other gangue minerals were mainly quartz, feldspar, and mica.

[0035] Unless otherwise specified, the chemical reagents used in the following specific examples are all conventional commercially available products.

[0036] Example 1

[0037] The specific process flow for treating this spodumene tailings using this method is as follows: Figure 1 As shown

[0038] After the spodumene tailings were re-adjusted, the flotation feed concentration was controlled at about 45 wt.%. The pH of the pulp was adjusted to 10.0 by a composite alkali consisting of caustic soda and soda ash in a 1:1 mass ratio. The combined anionic and cationic collectors polyetheramine (D-230) and sodium oleate were added at a rate of 350 g / t and 350 g / t relative to the feed, respectively. After aeration and stirring for 5 minutes, the mica roughing operation was carried out. During the roughing operation, the pulp pH was stabilized at about 10. The amount of combined collector used in the scavenging operation was halved.

[0039] The scavenging tailings are used for beryl pre-enrichment. Sodium hexametaphosphate, a depressant, is added at a rate of 100 g / t relative to the scavenging tailings. A metal-hydroxyoxime acid organic complex, composed of iron ions and octyl hydroxamic acid in a 1:1 molar ratio, is added at a rate of 250 g / t relative to the scavenging tailings, as well as sodium oleate at a rate of 250 g / t relative to the scavenging tailings, as pre-enrichment collectors for beryl. Sodium hexametaphosphate is used as a depressant in the first three cleaning stages, with the dosage decreasing progressively relative to the scavenging tailings: 60 g / t, 40 g / t, and 20 g / t, respectively. The amount of collector added in the scavenging stage is halved compared to the roughing stage. The resulting concentrate is the beryl rough concentrate.

[0040] After regrinding the beryl concentrate in a ball mill for 2 minutes to meet the grinding fineness requirement of -0.074 mm 90%, sodium carbonate was added to readjust the slurry to a concentration of 30 wt% and a pH of 9.5. Sodium hexametaphosphate and EDTA were added as inhibitors at a rate of 60 g / t relative to the regrinded concentrate and 120 g / t relative to the regrinded concentrate. After aeration and stirring for 5 minutes, the beryl was separated for upgrading. Beryl floated to the concentrate along with the foam product, while its gangue minerals were suppressed and entered the tailings. In the first cleaning process, sodium hexametaphosphate and EDTA were added as inhibitors at a rate of 30 g / t relative to the regrinded concentrate and 60 g / t relative to the regrinded concentrate. In the second cleaning process, sodium hexametaphosphate and EDTA were added as inhibitors at a rate of 15 g / t relative to the regrinded concentrate and 30 g / t relative to the regrinded concentrate. The beryl concentrate was obtained after two cleaning processes.

[0041] As shown in Tables 1-3, the method of this invention for treating spodumene tailings not only ensures the grade of beryl but also improves its recovery rate, producing a beryl concentrate product with a BeO grade of 6.12% and a recovery rate of 45.86%. The metal-hydroxyoxime acid complex + fatty acid collector system effectively enriches beryllium minerals, allowing beryl minerals to float preferentially to obtain a rough beryl concentrate without collecting mica. Open-circuit flotation yields a rough beryl concentrate with a BeO grade of 3.15% and a recovery rate of 65%, while closed-circuit flotation yields a rough beryl concentrate with a BeO grade of 2.54% and a recovery rate of 73.9%. The introduction of EDTA as a highly selective inhibitor for upgrading the rough beryl concentrate ensures that the pulp pH remains relatively stable under alkaline conditions throughout the flotation process, ultimately achieving enhanced flotation recovery of low-grade beryl from spodumene tailings. This technical solution is simple to operate in the beneficiation of spodumene tailings, has low reagent costs, and is highly applicable. It also provides guidance for the enhanced flotation recovery of low-grade beryl in spodumene and is conducive to further promotion and application.

[0042]

[0043]

[0044]

[0045] Control group 1

[0046] Control group 1 was used for comparison with Example 1, the only difference being the use of sodium oleate as the collector for beryl flotation. As a control, the superiority of the combined flotation reagents of the present invention was evaluated; the flotation process and reagent dosage of the control group were consistent with those of Example 1.

[0047] For the scavenging tailings produced by the closed-circuit flotation of mica in the front end, open-circuit flotation of beryl was carried out. In the roughing operation, the dosage of sodium hexametaphosphate inhibitor relative to tailings was 100 g / t, and the dosage of sodium oleate collector relative to tailings was 500 g / t. In the cleaning operation, the dosage of sodium hexametaphosphate relative to tailings was 60 g / t, 40 g / t, and 20 g / t, respectively. In the scavenging operation, the dosage of sodium oleate relative to tailings was 250 g / t. After one roughing, three cleaning, and one scavenging flotation operation, the index results of the open-circuit flotation mixed concentrate are shown in Table 4 below.

[0048]

[0049] The flotation test results in the table show that this flotation process can obtain beryl rough concentrate with a BeO grade of 0.4% and a recovery rate of 7.12%. Compared with the beryl rough concentrate with a BeO grade of 3.15% and a recovery rate of 65.15% obtained by the process of this invention, the collector has low selectivity for beryl during beryl pre-enrichment, resulting in poor flotation effect and ineffective recovery of beryllium resources, thus wasting resources.

[0050] Control group 2

[0051] Control group 2 was used for comparison with Example 1, the only difference being the use of a single metal-hydroxyxamic acid complex as the collector for beryl flotation. As a control, the superiority of the combined flotation reagents of the present invention was evaluated; the flotation process and reagent dosage in the control group were consistent with those in Example 1.

[0052] For the scavenging tailings produced by the closed-circuit flotation of mica in the front end, open-circuit flotation of beryl was carried out. In the roughing operation, the amount of sodium hexametaphosphate inhibitor relative to the scavenging tailings was 100 g / t, and the amount of metal-hydroxyoxime acid organic complex composed of iron ions and octyl hydroxamic acid in a molar ratio of 1:1 was added relative to the scavenging tailings was 500 g / t. In the cleaning operation, the amount of sodium hexametaphosphate relative to the scavenging tailings was 60 g / t, 40 g / t, and 20 g / t, respectively. In the scavenging operation, the amount of metal-hydroxyoxime acid organic complex composed of iron ions and octyl hydroxamic acid in a molar ratio of 1:1 was added relative to the scavenging tailings was 250 g / t. After one roughing, three cleaning, and one scavenging flotation operation, the index results of the open-circuit flotation mixed concentrate are shown in Table 5 below.

[0053]

[0054] The flotation test results in the table show that this flotation process can obtain beryl rough concentrate with a BeO grade of 0.21% and a recovery rate of 3.65%. Compared with the beryl rough concentrate with a BeO grade of 3.15% and a recovery rate of 65.15% obtained by the process of this invention, the collector has almost no selectivity for beryl during beryl pre-enrichment. The beryllium enrichment in the beryl rough concentrate is most likely due to the influence of the fatty acid collector remaining in the pulp during the pre-removal of mica. The flotation effect is extremely poor, and the beryllium resources are basically not effectively recovered, resulting in a serious waste of resources.

[0055] Control group 3

[0056] Control group 3 was used for comparison with Example 1, the only difference being the use of sodium oleate + sodium dodecyl sulfate as the collector for beryl flotation. As a control, the superiority of the combined flotation reagents of the present invention was evaluated; the flotation process and reagent dosage of the control group were consistent with those of Example 1.

[0057] For the scavenging tailings from the pre-removed mica flotation closed-circuit output, open-circuit flotation of beryl was performed. In the roughing operation, sodium hexametaphosphate (100 g / t relative to the scavenging tailings) and sodium dodecyl sulfate (250 g / t and oleate (250 g / t relative to the scavenging tailings) were added as beryl pre-enrichment collectors. In the cleaning operation, sodium hexametaphosphate was added at 60 g / t, 40 g / t, and 20 g / t respectively. The collector dosage in the scavenging operation was halved relative to the roughing dosage. The results of the open-circuit flotation mixed concentrate obtained after one roughing, three cleaning, and one scavenging operation are shown in Table 6 below.

[0058]

[0059] As can be seen from the flotation test results in Table 6, this flotation process can obtain a beryl rough concentrate with a BeO grade of 0.83% and a recovery rate of 13.18%. Compared with the beryl rough concentrate with a BeO grade of 3.15% and a recovery rate of 65.15% obtained by the process of this invention, this collector has a slight selectivity for beryl during beryl pre-enrichment. This is due to the intermolecular synergistic co-adsorption of sodium dodecyl sulfate and sodium oleate, two anionic collectors, on the mineral surface. However, the selectivity of this physical co-adsorption is very low. It adsorbs not only on the beryl surface but also on the surfaces of all positively charged or weakly negatively charged gangue minerals, causing gangue minerals to float together, reducing the concentrate grade, resulting in poor flotation effect, ineffective recovery of beryllium resources, and waste of resources.

[0060] Example 2

[0061] After the spodumene tailings were re-adjusted, the flotation feed concentration was controlled at about 45 wt.%. The pH of the pulp was adjusted to 10.0 using a composite alkali consisting of caustic soda and soda ash in a mass ratio of 2:1. The combined anionic and cationic collectors polyetheramine (D-230) and sodium linoleate were added at a rate of 350 g / t and 300 g / t relative to the feed, respectively. After aeration and stirring for 5 minutes, mica roughing was carried out. During the roughing process, the pulp pH was stabilized at about 10. The amount of combined collector used in the scavenging operation was halved.

[0062] The scavenging tailings are used for beryl pre-enrichment. Sodium hexametaphosphate, a depressant, is added at a rate of 120 g / t relative to the scavenging tailings. A metal-hydroxyoxime acid organic complex, composed of iron ions and octyl hydroxamic acid in a 1:1 molar ratio, is added at a rate of 300 g / t relative to the scavenging tailings, and sodium linoleate is added at a rate of 200 g / t relative to the scavenging tailings as a beryl pre-enrichment collector. Sodium hexametaphosphate is used as a depressant in the first three cleaning stages, with the dosage decreasing progressively relative to the scavenging tailings: 60 g / t, 30 g / t, and 15 g / t, respectively. The amount of collector added in the scavenging stage is halved compared to the roughing stage. The resulting concentrate is the beryl rough concentrate.

[0063] After regrinding the beryl concentrate in a ball mill for 2 minutes to meet the grinding fineness requirement of -0.074 mm 90%, sodium carbonate was added to readjust the slurry to a concentration of 32 wt% and a pH of 9.5. Sodium hexametaphosphate and EDTA were added as inhibitors at a dosage of 60 g / t relative to the regrinded concentrate and 100 g / t relative to the regrinded concentrate. After aeration and stirring for 5 minutes, the beryl was separated for upgrading. Beryl floated to the concentrate with the foam product, while its gangue minerals were suppressed and entered the tailings. In the first cleaning process, sodium hexametaphosphate and EDTA were added as inhibitors at a dosage of 30 g / t relative to the regrinded concentrate and 50 g / t relative to the regrinded concentrate. In the second cleaning process, sodium hexametaphosphate and EDTA were added as inhibitors at a dosage of 15 g / t relative to the regrinded concentrate and 25 g / t relative to the regrinded concentrate. After two cleaning processes, beryl concentrate was obtained.

[0064] As can be seen from the flotation test results in Tables 7 and 8, the technical solution of this invention can achieve efficient flotation recovery of beryl from spodumene tailings. Closed-circuit flotation yielded a beryl rough concentrate with a BeO grade of 2.6% and a recovery rate of 74.7%. The entire closed-circuit process produced a beryl concentrate product with a BeO grade of 6.03% and a recovery rate of 48.8%. This technical solution is simple to operate in the beneficiation of spodumene tailings, has low reagent costs, and is highly applicable. It has guiding significance for the comprehensive recovery of beryllium resources in spodumene and is conducive to further promotion and application.

[0065]

[0066]

[0067] Example 3

[0068] After the spodumene tailings were re-adjusted, the flotation feed concentration was controlled at about 45 wt.%. The pH of the pulp was adjusted to 10.0 using a composite alkali consisting of caustic soda and soda ash in a mass ratio of 3:1. The combined anionic and cationic collectors polyetheramine (D-230) and sodium oleate were added at a rate of 400 g / t and 300 g / t relative to the feed, respectively. After aeration and stirring for 5 minutes, mica roughing was carried out. During the roughing process, the pulp pH was stabilized at about 10. The amount of combined collector used in the scavenging operation was halved.

[0069] The scavenging tailings are used for beryl pre-enrichment. Sodium hexametaphosphate, a depressant, is added at a rate of 120 g / t relative to the scavenging tailings. A metal-hydroxyoxime acid organic complex, composed of lead ions and octyl hydroxamic acid in a 1:1 molar ratio, is added at a rate of 300 g / t relative to the scavenging tailings, and sodium oleate is added at a rate of 250 g / t relative to the scavenging tailings as a beryl pre-enrichment collector. Sodium hexametaphosphate is used as a depressant in the first three cleaning stages, with the dosage decreasing progressively relative to the scavenging tailings: 60 g / t, 30 g / t, and 15 g / t, respectively. The amount of collector added in the scavenging stage is halved compared to the roughing stage. The resulting concentrate is the beryl rough concentrate.

[0070] After regrinding the beryl concentrate in a ball mill for 2 minutes to meet the grinding fineness requirement of -0.074 mm 90%, sodium carbonate was added to readjust the slurry to a concentration of 28 wt% and a pH of approximately 9.5. Sodium hexametaphosphate and EDTA were added as inhibitors at a rate of 60 g / t relative to the regrinded concentrate and 100 g / t respectively. After aeration and stirring for 5 minutes, the beryl was separated for upgrading. Beryl floated to the concentrate along with the foam product, while its gangue minerals were suppressed and entered the tailings. In the first cleaning process, sodium hexametaphosphate and EDTA were added at a rate of 30 g / t relative to the regrinded concentrate and 50 g / t respectively. In the second cleaning process, sodium hexametaphosphate and EDTA were added at a rate of 15 g / t relative to the regrinded concentrate and 25 g / t respectively. After two cleaning processes, beryl concentrate was obtained.

[0071] As can be seen from the flotation test results in Tables 9 and 10, the technical solution of this invention can achieve efficient flotation recovery of beryl from spodumene tailings. Closed-circuit flotation yields a beryl rough concentrate with a BeO grade of 2.59% and a recovery rate of 75.22%. The entire closed-circuit process produces a beryllium concentrate with a BeO grade of 6.05% and a recovery rate of 47.15%. This technical solution is simple to operate in the beneficiation of spodumene tailings, has low reagent costs, and is highly applicable. It has guiding significance for the comprehensive recovery of beryllium resources in spodumene and is conducive to further promotion and application.

[0072]

[0073]

Claims

1. A method for enhanced flotation recovery of low grade beryl from lithium spodumene tailings, characterized by: It comprises the following steps: 1) Spodumene tailings are subjected to conditioning with a combination of amine and fatty acid as collectors and are subjected to flotation I to obtain mica concentrate and tailings I; 2) Tailings I is conditioned with phosphate as depressant Metal-hydroxamic acid organic complex and fatty acid as combined collector Flotation II is carried out to obtain a coarse beryl concentrate and tailings II; 3) Slurry the coarse beryl concentrate after regrinding, using phosphates and EDTA as combined depressants , and perform Flotation III to obtain a beryl concentrate and a tailing III.

2. A process for enhanced flotation recovery of low to medium grade tourmaline from spodumene tailings according to claim 1, characterized in that: The beryllium minerals in the spodumene tailings include beryl, and the mass content of BeO is ≥0.03%.

3. A process for enhanced flotation recovery of low to medium grade tourmaline from spodumene tailings according to claim 1 characterized in that: After the spodumene tailings are adjusted in consistency, the consistency of the ore slurry is adjusted to 45-50 wt.%, and the pH is adjusted to 9.5-10.5; wherein the pH adjustment adopts a composite alkali composed of caustic soda and soda ash in a mass ratio of (1-3):

1.

4. The method according to claim 1, characterized in that: The combined collector consists of amine and fatty acid in a mass ratio of (1-2):1; The amines include at least one of polyether amines, C8-C 13 alkyl ether amines, ether diamines, C8-C 13 fatty amines. The fatty acids include at least one of sodium oleate, linoleic acid, naphthenic acid, tall oil, lauric acid, linolenic acid, palmitic acid, stearic acid, ricinoleic acid, and 731 oxidized paraffin soap.

5. The method according to any one of claims 1-4, characterized in that: The flotation I includes one roughing and one scavenging; The roughing reagent system is: combined collector The dosage relative to the raw ore is 600-800 g / t; The selective reagent regime is: combined collectors at half the dosage relative to rougher.

6. A process for enhanced flotation recovery of low to medium grade tourmaline from spodumene tailings as claimed in claim 1, wherein: After the tailings I are adjusted in consistency, the pH of the ore slurry is adjusted to 9.5-10.

0.

7. The method according to claim 1, characterized in that: The combination collector The metal-hydroxamic acid organic complex and the fatty acid are measured in a mass ratio of (1-4):

1. The metal-hydroxamic acid organic complex is formed by coordination of a divalent or higher metal ion and a hydroxamic acid organic ligand in a molar ratio of 1:(1-12); The divalent or more metal ions include at least one of Ca 2+ , Mg 2+ , Zn 2+ , Fe 2+ , Pb 2+ , Cu 2+ , Mn 2+ , Fe 3+ , or Al 3+ ​ The hydroxamic acid organic ligand includes at least one of benzohydroxamic acid, salicylhydroxamic acid, and C6-Ci2alkylhydroxamic acid. 12 The hydroxamic acid organic ligand includes at least one of benzohydroxamic acid, salicylhydroxamic acid, and C6-Ci2alkylhydroxamic acid. The inhibitors are phosphates; The phosphate salt includes at least one of sodium metaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate.

8. The method according to claim 1, 6 or 7, characterized in that: The flotation II includes one roughing, one scavenging, and three cleanings; The roughing reagent system is: combined collector Relative tailings The addition amount is 400~600g / t; depressant Relative tailings The addition amount is 100~120g / t; The selected pharmaceutical regimen is: inhibitors The amount follows the principle of gradual decrease relative to the rough selection; The scavenging reagent regime is: combined collector The dosage is halved relative to the roughing.

9. A process for enhanced flotation recovery of low to medium grade tourmaline from lithium spodumene tailings according to claim 1 characterized in that: The regrinding treatment is to control the particle size so that the mass ratio of the-0.074 mm particle size is not less than 90%.

10. The method according to claim 1 or 9, characterized in that: The flotation III includes one roughing and two cleanings; The crude selection of the pharmaceutical regimen is: combination inhibitor The amount of relative beryl rough concentrate is 120-180 g / t, In the process of the roughing, the consistency of the ore slurry system is 25-35 wt / %, and the pH is stabilized at 9.5-10.0; The selected pharmaceutical regimen is: combination inhibitors The amount is halved relative to the rough selection; The combination inhibitor consists of EDTA and phosphate in a mass ratio of 3-4:1-2; The phosphate salt includes at least one of sodium metaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate.

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