Application of organic inhibitor applicable under neutral to alkaline conditions in spodumene ore flotation process and spodumene ore flotation process

Abstract

The invention belongs to the field of mineral processing, and discloses application of an organic inhibitor applicable under neutral to alkaline conditions in a spodumene ore flotation process, and the organic inhibitor comprises at least one of a polycarboxylic acid high-performance water reducing agent, a sulfamate high-efficiency water reducing agent, a melamine resin high-efficiency water reducing agent and a ketoaldehyde condensate high-efficiency water reducing agent. The invention further discloses a flotation process of spodumene ore. The invention finds and verifies that at least one of PCE, ASF, SMF and SAF can be used as an efficient spodumene flotation organic inhibitor for the first time and belongs to a macromolecular organic inhibitor, and the macromolecular organic inhibitor has differentiated competitive adsorption capacity on the surfaces of spodumene and gangue minerals (feldspar and quartz); the method has the double advantages of enhanced separation in a high-alkali system and efficient flotation in a neutral system. A brand-new and non-traditional inhibitor selection is provided for separation of spodumene and gangue minerals, and the technical limitation of dependence on traditional inhibitors such as sodium carbonate for a long time is broken through.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing, and particularly relates to the application of a class of organic inhibitors suitable for neutral to alkaline conditions in the flotation process of spodumene ore and the flotation process of spodumene ore. Background Technology

[0002] Lithium is an important energy metal, widely used in glass, ceramics, batteries, aerospace, and other fields due to its superior physicochemical properties. Currently, my country's main lithium extraction resources are hard rock ores, especially granite pegmatite lithium ores. In pegmatite lithium ores, spodumene is the most important lithium-extraction mineral, which is usually closely associated with gangue minerals such as feldspar and quartz. Flotation is the main method for beneficiating and enriching lithium from pegmatite spodumene ores.

[0003] Because spodumene has similar physicochemical properties to its gangue minerals such as feldspar and quartz, high-alkali flotation is currently the primary method for separating spodumene from these gangue minerals. The high-alkali flotation process for spodumene ore selectively dissolves the surfaces of spodumene and its gangue minerals by adding large amounts of sodium carbonate and sodium hydroxide before grinding and flotation, thereby enhancing the selectivity of the reagents and ultimately achieving flotation separation. However, because the modifiers sodium carbonate and sodium hydroxide used in the high-alkali process have poor selectivity, large quantities are required in practical applications. This results in a highly alkaline environment with a pH > 12, which makes subsequent tailings settling and dewatering difficult and also damages the mining environment.

[0004] To address the settling problem of tailings in high-alkali flotation, the industry has begun exploring neutral spodumene flotation processes. This process aims to improve tailings settling performance by avoiding the use of large amounts of strong alkali modifiers. Typically, neutral flotation requires highly efficient depressants to separate spodumene from gangue minerals. Traditional depressants, such as starch and phosphates, often lack ideal selectivity for gangue minerals under neutral conditions, resulting in spodumene concentrate grades and recoveries that are difficult to achieve at the levels of high-alkali processes, thus limiting its industrial application.

[0005] In summary, existing spodumene flotation technology faces a dilemma: while traditional high-alkali processes can achieve good flotation results, they inevitably lead to difficulties in tailings settling; while neutral processes can improve tailings settling, they often lack efficient and highly selective inhibitors, making it difficult to meet industrial requirements for flotation results (grade and recovery rate). Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above, and to provide an application of a class of organic inhibitors suitable for neutral to alkaline conditions in the flotation process of spodumene ore and the flotation process of spodumene ore. This class of organic inhibitors exhibits good inhibition performance in both neutral and alkaline flotation of spodumene ore.

[0007] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows: The application of a class of organic inhibitors suitable for neutral to alkaline conditions in the flotation process of spodumene ore, wherein the organic inhibitors include at least one of polycarboxylate superplasticizer (PCE), aminosulfonate superplasticizer (ASF), melamine resin superplasticizer (SMF), and ketone-aldehyde condensate superplasticizer (SAF).

[0008] In the above-mentioned applications, preferably, the organic inhibitor comprises, by mass percentage: 10-100% polycarboxylate high-performance water-reducing agent, 0-90% aminosulfonate high-efficiency water-reducing agent, 0-80% melamine resin high-efficiency water-reducing agent, and 0-80% ketone-aldehyde condensate high-efficiency water-reducing agent; the inhibitor components are compounded by physical mixing without chemical reaction, so as to obtain a stable and uniform organic inhibitor system.

[0009] In the above applications, preferably, the polycarboxylate superplasticizer (PCE) has the following structural formula:

[0010] The structural formula of the aminosulfonate superplasticizer (ASF) is: ; The structural formula of the melamine resin high-efficiency water-reducing agent (SMF) is: Its molecular weight is 3000-30000; The structural formula of the ketaldehyde condensate high-efficiency water-reducing agent (SAF) is as follows: Its molecular weight is 4000-10000.

[0011] As a general inventive concept, the present invention also provides a flotation process for spodumene ore, comprising the following steps: (1) Crushing and grinding spodumene ore to obtain mineral powder; (2) Adjust the slurry with the mineral powder, add the above-mentioned organic inhibitor and collector, and carry out flotation to obtain spodumene concentrate.

[0012] In the above-mentioned flotation process for spodumene ore, preferably, in step (2), based on the slurry, the amount of the inhibitor is 20-500 g / t, and the collector is fatty acid, sodium fatty acid or a mixture of the above-mentioned fatty acid and amine, with an amount of 50-2000 g / t.

[0013] In the preferred embodiment of the flotation process for spodumene ore described above, step (2) further includes adding a modifier to the slurry, wherein the modifier is Na2CO3, NaOH or CaCl2; the amount of Na2CO3 is 400-1500 g / t, the amount of NaOH is 800-1500 g / t, and the amount of CaCl2 is 30-50 g / t.

[0014] In the above-mentioned flotation process of spodumene ore, preferably, in step (2), after adding the modifier and stirring for 3-40 min, an organic inhibitor is added, after stirring for 3-30 min, a collector is added, and after stirring for 3-30 min, a first-stage roughing and a third-stage cleaning process is carried out.

[0015] In the above-mentioned flotation process of spodumene ore, preferably, in step (2), an organic inhibitor is added, and after stirring and reacting for 3-30 minutes, a collector is added, and after stirring and reacting for 3-30 minutes, a first-stage roughing process is carried out, or a first-stage roughing and three-stage cleaning process is carried out.

[0016] In the above-mentioned flotation process for spodumene ore, preferably, the pH value of the pulp during the flotation process is 7-13.

[0017] In the above-mentioned flotation process for spodumene ore, preferably, in step (1), the powder with a particle size smaller than 0.074 mm accounts for 60-90% of the total powder mass.

[0018] This invention uses at least one of polycarboxylate superplasticizer (PCE), aminosulfonate superplasticizer (ASF), melamine resin superplasticizer (SMF), and ketone-aldehyde condensate superplasticizer (SAF) as a gangue mineral inhibitor in spodumene flotation. In a mixed cationic and anionic collector system, the organic inhibitor and the collector are adsorbed onto the surface of spodumene and its gangue minerals (e.g., feldspar, quartz) via chemisorption. At this time, the organic inhibitor and the collector compete for adsorption on the mineral surface. The collector's adsorption on the spodumene surface is stronger than that of the inhibitor. Even if the inhibitor added first is adsorbed onto the spodumene surface via sulfonate, the inhibitor pre-adsorbed on the spodumene surface can be displaced by the subsequently added collector after the collector is added, thus causing a large amount of spodumene to float. On the gangue mineral (e.g., feldspar, quartz) surface, the opposite is true. The adsorption of the collector on the surface of the gangue mineral is weaker than that of the inhibitor. The subsequently added collector cannot displace the inhibitor pre-adsorbed on the gangue mineral surface, thus causing the gangue mineral to sink and become the product in the tank.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention is the first to discover and confirm that at least one of PCE, ASF, SMF, and SAF can be used as a highly efficient organic depressant for spodumene flotation. These are macromolecular organic depressants, and these macromolecular organic compounds have differentiated competitive adsorption capabilities on the surfaces of spodumene and gangue minerals (feldspar, quartz), offering advantages such as low depressant dosage, high selectivity, and environmental friendliness. This provides a novel and unconventional depressant option for the separation of spodumene and gangue minerals, breaking through the long-standing technical limitations of relying on traditional depressants such as sodium carbonate.

[0020] (2) When the inhibitor of the present invention is applied to a neutral (pH=7) flotation system, it can achieve strong and highly selective inhibition of gangue minerals, resulting in excellent flotation separation of spodumene. Under these conditions, the grade and recovery rate of the spodumene concentrate can be comparable to the index levels of traditional high-alkali processes. This means that by adopting the technical solution of the present invention, the use of alkali (such as sodium hydroxide and sodium carbonate) can be eliminated without sacrificing separation efficiency, thereby greatly improving the settling and dewatering performance of flotation tailings and achieving green, low-carbon, and clean production.

[0021] (3) The inhibitor of the present invention is not only applicable to neutral processes, but also has important value in existing traditional high-alkali flotation systems. When used as an auxiliary inhibitor in combination with conventional reagents (such as sodium hydroxide and sodium oleate), it can produce a significant synergistic effect with the traditional inhibitor sodium carbonate, further enhancing the inhibition ability on gangue minerals. Thus, on the basis of the original high-alkali process, the grade and recovery rate of spodumene concentrate can be further improved. This characteristic enables the inhibitor of the present invention to serve as a highly efficient "synergist" to improve production efficiency and economic benefits at extremely low cost. Attached Figure Description

[0022] Figure 1 This is a flotation process flow diagram of Comparative Example 1 of the present invention.

[0023] Figure 2 This is a flotation process flow diagram of Embodiments 1 and 2 of the present invention.

[0024] Figure 3 This is a flotation process flow diagram of Embodiments 3, 4 and 5 of the present invention.

[0025] Figure 4 This is a flotation process flow diagram of Embodiments 6 and 7 of the present invention. Detailed Implementation

[0026] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0027] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0028] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0029] Comparative Example 1: High-alkali flotation (pH=12) The spodumene ore involved in Comparative Example 1 was taken from a spodumene mine in Xinjiang. The chemical composition of the test sample was as follows: Li2O content 1.03%, Al2O3 content 14.52%, SiO2 content 72.58%, Na2O content 4.08%, K2O content 2.49%, Fe2O3 content 2.09%, CaO content 0.47%, MgO content 0.16%, and the balance being other trace elements.

[0030] The flotation process and parameters for this comparative example of spodumene ore are as follows: Figure 1 As shown, crushing and grinding: spodumene ore was crushed by a jaw crusher and ground by a rod mill to obtain spodumene ore powder with a particle size of less than 0.074 mm accounting for about 75% by mass. Then, using the traditional high-alkali inhibitor sodium carbonate and collector YOA (oleic acid: dodecylamine molar ratio of 10:1), flotation was carried out under the conditions of pH=12 and stirring speed of 1992 r / min, after one stage of roughing and three stages of cleaning. The results are shown in Table 1.

[0031] Table 1 Flotation test results 1 / %

[0032] Example 1: High-alkali flotation (pH=12) The flotation process of spodumene ore in Example 1 is as follows: Figure 2 As shown, crushing and grinding: spodumene ore was crushed by a jaw crusher and ground by a rod mill to obtain spodumene ore powder with a particle size of less than 0.074 mm accounting for about 75% by mass. Then, a single-component inhibitor ASF (roughing: 40 g / t; cleaning: 20 g / t) was used in combination with the traditional inhibitor sodium carbonate. The collector system was the same as that of Comparative Example 1. After one roughing stage and two cleaning stages, under flotation conditions of pH=12 and stirring speed of 1992 r / min, the results are shown in Table 2.

[0033] Table 2 Flotation test results 2 / %

[0034] As can be seen from the results of Example 1 and Comparative Example 1, the single-component inhibitor ASF of the present invention can effectively enhance the separation selectivity and simplify the process in the traditional high-alkali system, and significantly improve the lithium recovery efficiency while maintaining the concentrate grade, demonstrating significant technological progress and industrial application value.

[0035] Example 2: High-alkali flotation (pH=12) This Example 2 is based on the processes of Comparative Example 1 and Example 1, with the addition of the two-component inhibitors ASF and SAF of the present invention, wherein the mass ratio of ASF to SAF is 1:1. The two-component inhibitors are used at a dosage of 40 g / t during roughing (i.e., 20 g / t each of ASF and SAF) and 20 g / t during cleaning (i.e., 10 g / t each of ASF and SAF), with other conditions the same as in Example 1. The flotation process flow of spodumene ore in this Example 2 is as follows: Figure 2 As shown, the results obtained by using the two-component inhibitor system (ASF+SAF) of the present invention in combination with the traditional inhibitor sodium carbonate, after one stage of roughing and two stages of fine selection, under flotation conditions of pH=12 are shown in Table 3.

[0036] Table 3 Flotation test results 3 / %

[0037] The results from Example 2, Example 1, and Comparative Example 1 show that the two-component inhibitor ASF and SAF system exhibits better sorting selectivity than the single-component ASF system, further achieving efficient selective separation and process optimization under high alkalinity conditions, fully demonstrating the practicality and promotional value of this invention in industrial applications.

[0038] Example 3: Neutral flotation (pH=7) The spodumene ore involved in this embodiment is the same as that in Embodiments 1 and 2.

[0039] This embodiment simultaneously conducted three parallel comparative experiments. The inhibitor used was the single-component inhibitor of this invention, and the collector was the same as in Example 1. The experiment was conducted at pH=7 and a stirring speed of 1992 r / min, and the process flow is as follows: Figure 3 As shown.

[0040] The results of the first-stage roughing process show that using the single-component inhibitor SMF (at a dosage of 200 g / t) yields a spodumene rough concentrate with a Li2O grade of 2.95% and a recovery rate of 80.63%; using the single-component inhibitor ASF (at a dosage of 150 g / t) yields a spodumene rough concentrate with a Li2O grade of 2.77% and a recovery rate of 93.15%; and using the single-component inhibitor SAF (at a dosage of 200 g / t) yields a spodumene rough concentrate with a Li2O grade of 2.86% and a recovery rate of 84.24%.

[0041] As can be seen from the results of Example 3, SMF, ASF and SAF, as flotation depressants, have excellent performance in the neutral flotation of actual spodumene ore with short process flow and significant grade improvement and high recovery rate. They have outstanding effects and good prospects for industrial application.

[0042] Example 4: Neutral flotation (pH=7) This embodiment uses a single-component inhibitor SMF at a dosage of 200 g / t. The process differs from that in Example 3 in that the stirring time of the collector YOA is adjusted to 90 min. Other conditions are the same as in Example 3. The result is that a spodumene rough concentrate with a Li2O grade of 3.23% and a recovery rate of 80.36% can be obtained.

[0043] The results of Example 4 demonstrate that appropriately extending the collector stirring time is a simple and effective process optimization method in neutral flotation systems. This measure can significantly improve concentrate grade without significantly affecting lithium recovery, further enhancing the application advantages of this neutral, efficient, and environmentally friendly new flotation process, and providing reliable technical support for the clean and efficient utilization of complex spodumene ores.

[0044] Example 5: Neutral flotation (pH=7) This embodiment uses a single-component inhibitor, SMF, at a dosage of 200 g / t. The process differs from Example 3 in that the stirring speed is adjusted to 2604 r / min, while other conditions remain the same. Results show that a spodumene rough concentrate with a Li₂O grade of 3.05% and a recovery rate of 74.86% can be obtained.

[0045] The results of Example 5 show that, in the neutral flotation process, increasing the stirring speed and correspondingly shortening the stirring time can also improve the concentrate grade. This provides another efficient parameter control strategy for the neutral flotation process, demonstrating that by optimizing kinetic conditions (such as stirring intensity and time), it is possible to improve separation efficiency and increase product grade while ensuring a certain recovery rate. This scheme provides a flexible and diversified process option for neutral, efficient, and energy-saving flotation of spodumene ore, and has strong feasibility for industrial application.

[0046] Example 6: Neutral flotation (pH=7) The spodumene ore involved in this embodiment is the same as that in Embodiments 1 and 2.

[0047] The flotation process for spodumene ore in this embodiment is as follows: Figure 4As shown, a two-component inhibitor, SMF and PCE, with a mass ratio of 1:1 (20 g / t each, total dosage 40 g / t), and YOA (oleic acid: dodecylamine molar ratio of 10:1), was used. Under flotation conditions of pH=7 and stirring speed of 1992 r / min, the flotation was carried out through one roughing stage and three cleaning stages. The results are shown in Table 4.

[0048] Table 4 Flotation test results 4 / %

[0049] As can be seen from the results of Example 6, under neutral conditions, using the two-component inhibitors SMF and PCE, the Li2O recovery rate of the spodumene concentrate obtained reached 61.34%, and the grade was 5.10%. The results of Comparative Example 1, which obtained a Li2O recovery rate of 48.96% and a grade of 5.29% in a conventional high-alkali system (pH=12) without the addition of the inhibitors of the present invention, show that the neutral flotation process of the present invention using the two-component inhibitors SMF and PCE is significantly better than the conventional high-alkali process in terms of spodumene recovery rate, while maintaining a comparable concentrate grade.

[0050] Example 7: Neutral flotation (pH=7) The spodumene ore involved in this embodiment is the same as that in Embodiments 1 and 2.

[0051] This embodiment further examines the synergistic effect of the multi-component compound based on Embodiment 6. The flotation process for spodumene ore in this embodiment is as follows: Figure 4 As shown, a three-component inhibitor system of SMF, PCE, and SAF was used, with a mass ratio of 1:1:1 (approximately 13.3 g / t each, totaling 40 g / t). The collector system was the same as in Example 5, consisting of YOA (oleic acid: dodecylamine molar ratio of 10:1). Under flotation conditions of pH=7 and stirring speed of 1992 r / min, the flotation was carried out through a first-stage roughing and a third-stage cleaning process. The results are shown in Table 5.

[0052] Table 5 Flotation Test Results 5 / %

[0053] As can be seen from the results of Example 7, using the three-component inhibitor system of the present invention (SMF, PCE, and SAF), the Li₂O grade of spodumene concentrate was increased to 5.23%, and the recovery rate was 61.95%, both of which are superior to the two-component system of Example 5 and the traditional high-alkali flotation results of Comparison 1. This demonstrates that the three-component inhibitor system exhibits stronger separation selectivity, higher lithium recovery rate, and better system stability under neutral conditions, further validating the significant technological advancements and industrial application prospects of the present invention in low-alkali-neutral flotation systems.

[0054] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. The application of a class of organic inhibitors suitable for neutral to alkaline conditions in the flotation process of spodumene ore, characterized in that, The organic inhibitor includes at least one of polycarboxylic acid high-performance water-reducing agent, aminosulfonate high-efficiency water-reducing agent, melamine resin high-efficiency water-reducing agent, and ketone-aldehyde condensate high-efficiency water-reducing agent.

2. The application as described in claim 1, characterized in that, The organic inhibitors comprise, by mass percentage: 10-100% polycarboxylate high-performance water-reducing agent, 0-90% aminosulfonate high-efficiency water-reducing agent, 0-80% melamine resin high-efficiency water-reducing agent, and 0-80% ketone-aldehyde condensate high-efficiency water-reducing agent.

3. The application as described in claim 1 or 2, characterized in that, The structural formula of the polycarboxylate high-performance water-reducing agent is: ； The structural formula of the aminosulfonate high-efficiency water-reducing agent is: ； The structural formula of the melamine resin high-efficiency water-reducing agent is: Its molecular weight is 3000-30000; The structural formula of the ketaldehyde condensate high-efficiency water-reducing agent is: Its molecular weight is 4000-10000.

4. A flotation process for spodumene ore, characterized in that, Includes the following steps: (1) Crushing and grinding spodumene ore to obtain mineral powder; (2) Adjust the slurry with the mineral powder, add the organic inhibitor and collector as described in any one of claims 1-3 and perform flotation to obtain spodumene concentrate.

5. The flotation process for spodumene ore as described in claim 4, characterized in that, In step (2), based on the slurry, the amount of the organic inhibitor is 20-500 g / t, and the collector is fatty acid, sodium fatty acid or a mixture of the above and below with amines, with an amount of 50-2000 g / t.

6. The flotation process for spodumene ore as described in claim 4, characterized in that, Step (2) also includes adding a modifier to the slurry, wherein the modifier is Na2CO3, NaOH or CaCl2; the amount of Na2CO3 is 400-1500 g / t, the amount of NaOH is 800-1500 g / t, and the amount of CaCl2 is 30-50 g / t.

7. The flotation process for spodumene ore as described in claim 6, characterized in that, In step (2), after adding the modifier and stirring for 3-40 min, add the organic inhibitor, stir for 3-30 min, add the collector, stir for 3-30 min, and then carry out a first-stage roughing and three-stage cleaning process.

8. The flotation process for spodumene ore as described in claim 4, characterized in that, In step (2), an organic inhibitor is added, and after stirring for 3-30 minutes, a collector is added. After stirring for 3-30 minutes, a roughing process is performed, or a roughing process and a three-stage cleaning process are performed.

9. The flotation process for spodumene ore as described in claim 4, characterized in that, The pH value of the pulp during the flotation process is 7-13.

10. The flotation process for spodumene ore as described in claim 4, characterized in that, In step (1), the mineral powder with a particle size smaller than 0.074 mm accounts for 60-90% of the total powder mass.

Images