A morpholine heterocyclic hydroxamic acid collector and a preparation method thereof
By synthesizing heterocyclic hydroxamic acid collectors, the problems of insufficient collecting capacity and selectivity of existing hydroxamic acid collectors have been solved, achieving efficient collection of rare earth ores and ilmenite, and improving the grade and recovery rate of concentrates.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN TIANBAOXIANG TECH CO LTD
- Filing Date
- 2023-11-14
- Publication Date
- 2026-07-14
Smart Images
Figure QLYQS_1 
Figure BDA0004546053690000011 
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Abstract
Description
[Technical Field]
[0001] This invention belongs to the field of mineral processing reagents and relates to a novel heterocyclic hydroxamic acid collector and its preparation method. [Background Technology]
[0002] Hydroxyxamic acid, as a highly efficient collector in the flotation of oxidized ores, exhibits better collecting ability and selectivity compared to commonly used fatty acid collectors, and has been widely used in the flotation of rare earth ores, ilmenite, and tin-tantalum ores. Patent CN106269276A, "A Beneficiation Method and Flotation Reagents for the Comprehensive Recovery of Low-Grade Fine-Grained Tantalum-Niobium Resources," uses salicylic acid and C5-C9 hydroxyxamic acid as collectors for rare earth ores; Patent CN105583084A, "An Ilmenite Flotation Collector and Its Preparation Method," uses C7-C9 hydroxyxamic acid as an ilmenite collector; and Patent CN107520063B describes a method for synthesizing hydroxyxamic acids with a fatty acid carbon chain, and applies it to the flotation of rare earth minerals. Hydroxyxamic acid is an excellent collector for rare earth minerals, ilmenite, and tin oxides primarily because its oxime group contains both oxygen and nitrogen atoms, both of which possess lone pairs of electrons, allowing it to react with metal ions (Ce). 3+ Ti 4+ Sn 2+ When chelation occurs, stable chelates are formed, exhibiting high selectivity and harvesting ability. [Summary of the Invention]
[0003] The purpose of this invention is to synthesize a heterocyclic hydroxamic acid collector with a novel structure, stable performance, strong collecting ability, and high selectivity.
[0004] This invention provides a novel heterocyclic hydroxamic acid collector, the general structural formula of which is as follows:
[0005]
[0006] n is 0 to 16.
[0007] Another aspect of the present invention provides a method for preparing a heterocyclic hydroxamic acid collector, the method comprising the following steps:
[0008] (1) Synthesis of N-methyl carboxylate morpholine: Morpholine and methyl chloroalkyl carboxylate were used as raw materials, water was used as solvent, DMAP acylation reagent and a small amount of sodium carbonate were added at room temperature, and N-methyl carboxylate morpholine was generated by reaction at 0℃~100℃.
[0009] (2) The synthesis of hydroxamic acid was carried out using N-methyl carboxylate morpholine and hydroxylamine as raw materials, water as solvent, and inorganic base as neutralizing agent. The reaction temperature was 40℃~60℃ and the reaction time was 3.5 hours.
[0010] (3) Product post-processing: Cool the product after the oxime reaction in step (2) to 35°C, then slowly add a 20% to 50% dilute sulfuric acid solution, adjust the pH of the solution to around 6, vacuum filter and dry.
[0011] In the above technical solution, further, in step (1), solvent water, methyl chloroalkylcarboxylate and acylation reagent are added first, and after stirring and dispersing for 30 minutes, morpholine is added dropwise to the reaction system.
[0012] In the above technical solution, further, in step (1), the molar ratio of morpholine and methyl chloroalkylcarboxylate is 1:1.0 to 1.3, and the reaction time is 3 to 5 hours.
[0013] In the above technical solution, further, in step (1), the molar ratio of morpholine, acylation reagent and sodium carbonate is 1:0.1~0.3:1.1~1.5.
[0014] In the above technical solution, further, in step (2), the molar ratio of N-methyl carboxylate morpholine, hydroxylamine and sodium hydroxide is 1:1.1~1.5:2.2~3.0.
[0015] In the above technical solution, the hydroxylamine mentioned in step (2) is preferably hydroxylamine hydrochloride or hydroxylamine sulfate; the inorganic base is preferably sodium hydroxide or potassium hydroxide.
[0016] The advantages of the heterocyclic hydroxamic acid collector of the present invention are as follows: the nitrogen and oxygen atoms in the heterocyclic hydroxamic acid contain lone pairs of electrons, which is conducive to the formation of coordination compounds between the hydroxamic acid molecule and metal ions. Compared with ordinary hydroxamic acid, it has a stronger chelating ability and better collection and selectivity for useful minerals. [Detailed Implementation]
[0017] The present invention is further illustrated by the following embodiments, but is not limited to these embodiments. All parts and percentages in the embodiments refer to mass unless otherwise specified.
[0018] Example 1:
[0019] A certain amount of methyl chloropropionate and solvent water were placed in a flask. 10% molar amount of the acylation reagent DMAP was added, followed by 1.5 molar amounts of sodium carbonate. The mixture was stirred for 30 minutes, then 0.8 molar amounts of morpholine were added dropwise. The mixture was heated to 60°C and reacted for 4 hours, then cooled to room temperature. 1.2 molar amounts of hydroxylamine hydrochloride were added and stirred until dissolved. A 30% (w / w) aqueous solution of 2.5 molar amounts of sodium hydroxide was prepared and added dropwise to the reaction system. The mixture was heated to 50°C and reacted for 3.5 hours. After cooling to room temperature, a certain amount of dilute sulfuric acid was added to adjust the pH of the reaction system to approximately 6. The mixture was then vacuum filtered and dried to obtain morpholine-N-propylhydroxamic acid.
[0020] Example 2:
[0021] A certain amount of methyl chlorooctanoate and solvent water were placed in a flask. 10% molar amount of the acylation reagent DMAP was added, followed by 1.5 molar amounts of sodium carbonate. The mixture was stirred for 30 minutes, then 0.8 molar amounts of morpholine were added dropwise. The mixture was heated to 60°C and reacted for 4 hours, then cooled to room temperature. 1.2 molar amounts of hydroxylamine hydrochloride were added and stirred until dissolved. A 30% (w / w) aqueous solution of 2.5 molar amounts of sodium hydroxide was prepared and added dropwise to the reaction system. The mixture was heated to 50°C and reacted for 3.5 hours. After cooling to room temperature, a certain amount of dilute sulfuric acid was added to adjust the pH of the reaction system to approximately 6. The mixture was then vacuum filtered and dried to obtain morpholine-N-octylhydroxamic acid.
[0022] Example 3:
[0023] A certain amount of methyl chlorolaurate and solvent water were placed in a flask. 10% molar amount of the acylation reagent DMAP was added, followed by 1.5 molar amounts of sodium carbonate. The mixture was stirred for 30 minutes, then 0.8 molar amounts of morpholine were added dropwise. The mixture was heated to 60°C and reacted for 4 hours, then cooled to room temperature. 1.2 molar amounts of hydroxylamine hydrochloride were added and stirred until dissolved. A 30% (w / w) aqueous solution of 2.5 molar amounts of sodium hydroxide was prepared and added dropwise to the reaction system. The mixture was heated to 50°C and reacted for 3.5 hours. After cooling to room temperature, a certain amount of dilute sulfuric acid was added to adjust the pH of the reaction system to approximately 6. The mixture was then vacuum filtered and dried to obtain morpholine-N-lauryl hydroxyxamic acid.
[0024] Comparative Example 1: Buoyancy performance in rare earth flotation
[0025] A rare earth mine in Sichuan Province had a raw ore rare earth grade of 3.25% and a fineness of approximately 85% (-200 mesh). Water glass was used as a depressant, and pine oil as a frother. The flotation process consisted of one roughing and two cleaning stages. The flotation results for morpholine N-propylhydroxamic acid and salicylic acid are shown in Table 1. The results indicate that morpholine-N-propylhydroxamic acid exhibits better selectivity, resulting in improved concentrate grade and recovery.
[0026] Table 1. Flotation conditions and results for rare earth ores
[0027]
[0028] Comparative Example 2: Flotation performance in ilmenite flotation
[0029] A desulfurized ilmenite ore contained 22.18% TiO2, with approximately 60% being -200 mesh. After adjusting the pH with 1.8 kg / t sulfuric acid and undergoing a single roughing operation, a titanium rough concentrate was obtained. The flotation results for morpholine-N-octylhydroxamic acid, morpholine-N-laurylhydroxamic acid, and octylhydroxamic acid are shown in Table 1. The results indicate that compared to octylhydroxamic acid, using morpholine-N-octylhydroxamic acid and morpholine-N-laurylhydroxamic acid yields higher concentrate grades. Morpholine-N-laurylhydroxamic acid exhibits stronger collecting ability, while morpholine-N-octylhydroxamic acid shows better selectivity.
[0030] Table 2. Flotation conditions and results for ilmenite.
[0031]
[0032]
Claims
1. A morpholino heterocyclic hydroxamic acid collector, characterized in that... The general structural formula of the collector is as follows: The collector is prepared by means of the step n, where n is 1 to 16. (1) Synthesis of N-methyl carboxylate morpholine: Morpholine and methyl chloroalkyl carboxylate were used as raw materials, water was used as solvent, DMAP acylation reagent and a small amount of sodium carbonate were added at room temperature, and N-methyl carboxylate morpholine was generated by reaction at 0℃~100℃. (2) The synthesis of hydroxamic acid was carried out using N-methyl carboxylate morpholine and hydroxylamine as raw materials, water as solvent, and inorganic base as neutralizing agent. The reaction temperature was 40℃~60℃ and the reaction time was 3.5 hours. (3) Product post-processing: Cool the product after the oxime reaction in step (2) to 35°C, then slowly add a 20% to 50% dilute sulfuric acid solution, adjust the pH of the solution to 6, vacuum filter and dry.
2. The morpholine heterocyclic hydroxamic acid collector according to claim 1, characterized in that, In step (1), first add solvent water, methyl chloroalkylcarboxylate and acylation reagent, stir and disperse for 30 minutes, and then add morpholine dropwise to the reaction system.
3. The morpholine heterocyclic hydroxamic acid collector according to claim 1, characterized in that, In step (1), the molar ratio of morpholine and methyl chloroalkylcarboxylate is 1:1.0 to 1.3, and the reaction time is 3 to 5 hours.
4. The morpholine heterocyclic hydroxamic acid collector according to claim 1, characterized in that, In step (1), the molar ratio of salicylaldehyde, acylation reagent and sodium carbonate is 1:0.1~0.3:1.1~1.
5.
5. The morpholine heterocyclic hydroxamic acid collector according to claim 1, characterized in that, In step (2), the molar ratio of N-methyl carboxylate morpholine, hydroxylamine and sodium hydroxide is 1:1.1-1.5:2.2-3.
0.
6. The morpholine heterocyclic hydroxamic acid collector according to claim 1, characterized in that, In step (2), hydroxylamine is hydroxylamine hydrochloride or hydroxylamine sulfate, and the inorganic base is sodium hydroxide or potassium hydroxide.