Method for efficiently removing octadecylamine on the surface of potassium chloride solid

Abstract

The application provides a method for efficiently removing octadecylamine on the surface of potassium chloride solid. The method comprises the following steps: immersing solid potassium chloride to be treated containing octadecylamine on the surface into a potassium chloride solution containing at least one kind of cation of lithium, sodium, magnesium, calcium, rubidium and cesium or containing sulfate or hydroxyl ion, removing the octadecylamine on the surface of the solid potassium chloride, then washing with saturated potassium chloride solution again, and drying to obtain purified solid potassium chloride. The method for removing octadecylamine on the surface of potassium chloride solid provided by the application has low cost, simple method and is easy to popularize.

Description

Technical Field

[0001] This invention belongs to the field of chemical impurity removal technology, specifically relating to a highly efficient method for removing octadecylamine from the solid surface of potassium chloride. Background Technology

[0002] Potassium chloride is widely used in agricultural fertilizers, chemical production, and dyes, and is an indispensable resource in my country. Due to the raw materials and systems involved in the potassium chloride production process, octadecylamine hydrochloride remains on the surface of the potassium chloride after flotation; simultaneously, a certain amount of ammonium salts also remain on the surface. This can significantly impact product quality and chemical safety during downstream processing and high-value-added processing. For example, in the electrolytic preparation of potassium hydroxide, the presence of amines / ammonium compounds can generate nitrogen trichloride during electrolysis, which, when present in high concentrations, can easily cause an explosion.

[0003] Currently, many companies have proposed solutions to the problem of high concentrations of nitrogen trichloride easily causing explosions. For example, Wang Xiaolei et al., based on the actual conditions of their production equipment, utilized the reaction of chlorine gas with ammonium ions under alkaline conditions to generate nitrogen gas, thereby achieving the purpose of removing ammonium. Sun Zengli adjusted the brine to alkalinity, with a pH of 9-10.5, then added sodium hypochlorite, and after heating it twice to 60°C, hypochlorous acid reacted with ammonia gas in the reactor to generate easily purged monochloramine and dichloramine. Zhou Maiyou utilized the reaction of ammonium compounds with hypochlorous acid to generate ammonium chloride, which reacted with sodium hypochlorite to generate ammonium hydride, and then purged with compressed air under heating conditions. These methods all remove ammonium salts based on the salt solution and do not address the removal of potassium chloride flotation agents. Although the nitrogen content in the flotation agent is relatively less than that in the ammonium salt, it still has an impact.

[0004] Researchers have also conducted relevant studies on how to remove octadecylamine hydrochloride. For example, Zhu Guilin provided a method for removing flotation agents from potassium chloride, which includes: dissolving potassium chloride raw material containing flotation agents in water to form a saturated solution, allowing the flotation agents to accumulate on the solution surface, adding filter aids to the saturated solution, and obtaining potassium chloride without flotation agents after filtration, crystallization, and drying. While this method can remove octadecylamine hydrochloride from potassium chloride, it introduces a filter aid and requires a dissolution and recrystallization process, resulting in high costs. Fei Wenli et al. studied the removal of octadecylamine hydrochloride, a collector, from potassium chloride flotation brine in salt lakes using macroporous resin adsorption. The results showed that D061 macroporous resin, under conditions of 25℃, pH 8–10, and a flow rate of 3 BV / h, achieved an adsorption ratio of 70 BV, and the adsorption rate of octadecylamine in simulated brine using D061 macroporous resin reached over 98%. Using 4% hydrochloric acid as a desorbent, at a flow rate of 1 BV / h, the backwashing ratio reached 2.5 BV, and the water washing ratio reached 4 BV. Using D061 macroporous resin in a two-stage series adsorption process to treat potassium chloride flotation brine in salt lakes, the removal rate of the flotation collector octadecylamine reached over 99%. Wang Pingping utilized dielectric barrier discharge plasma technology to treat octadecylamine hydrochloride in water. The results showed that when the initial concentration was 6 μg / mL, the discharge power was 160 W, the initial pH was 10, the aeration rate was 100 mL / min, and the treatment time was 60 min, the removal rate of octadecylamine reached 90%. However, the above methods for treating octadecylamine hydrochloride in salt lake brine have some drawbacks. Salt lake brine has a complex composition and high salinity, and the cost of using macroporous resins and ion exchange resins to adsorb octadecylamine is high, making large-scale application in actual production difficult.

[0005] In summary, while solution-based methods for removing octadecylamine hydrochloride or ammonium salts from potassium chloride can achieve high removal rates, they face challenges such as high production costs and limited applicability in high-salt systems. Therefore, there is an urgent need to provide a removal method that balances efficiency and cost. Summary of the Invention

[0006] The main objective of this invention is to provide a highly efficient method for removing octadecylamine from the solid surface of potassium chloride, thereby overcoming the shortcomings of the prior art.

[0007] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0008] This invention provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: immersing solid potassium chloride containing octadecylamine on its surface into a potassium chloride solution containing selected cations or selected anions, stirring and mixing thoroughly, and then filtering to remove octadecylamine from the surface of solid potassium chloride.

[0009] Furthermore, the selected cation includes any one or more combinations of lithium ions, sodium ions, magnesium ions, calcium ions, rubidium ions, and cesium ions.

[0010] Furthermore, the selected anion includes any one or a combination of two of sulfate ions and hydroxide ions.

[0011] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0012] The method for efficiently removing octadecylamine from the surface of potassium chloride solid provided by this invention can efficiently and cost-effectively remove octadecylamine from the surface of potassium chloride solid, avoiding the traditional dissolution and crystallization steps, simplifying the process, and not introducing other impurities. The entire impurity removal process is simple, environmentally friendly, and easy to promote. Detailed Implementation

[0013] Detailed embodiments of the invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the specific functional details disclosed herein should not be construed as limiting, but rather as the basis for the claims and as intended to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0014] In view of the deficiencies of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution of this invention will be clearly and completely described below. It mainly involves a highly efficient method for removing octadecylamine from the surface of solid potassium chloride. Without introducing organic matter, octadecylamine is removed from solid potassium chloride by washing with saturated potassium chloride solutions containing different concentrations and different cations. To further understand this invention, the technical solution, its implementation process, and principles will be further explained below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of this invention, and not for limiting the scope of the claims.

[0015] Specifically, as one aspect of the technical solution of the present invention, the efficient removal method of octadecylamine from the surface of solid potassium chloride includes: immersing the solid potassium chloride containing octadecylamine on the surface to be treated into a potassium chloride solution containing selected cations or selected anions, stirring and mixing thoroughly, and then filtering to remove octadecylamine from the surface of solid potassium chloride, thereby solving the problem of low-cost removal of the flotation agent octadecylamine from solid potassium chloride.

[0016] In some preferred embodiments, the preparation method includes immersing solid potassium chloride containing octadecylamine on its surface into a saturated potassium chloride solution containing selected cations or selected anions. The present invention preferably uses a saturated potassium chloride solution to obtain a higher yield.

[0017] In some specific embodiments, the selected cation includes any one or more combinations of cations selected from lithium ions, sodium ions, magnesium ions, calcium ions, rubidium ions, cesium ions, etc.

[0018] In some specific embodiments, the selected anion includes any one or a combination of two of sulfate ions, hydroxide ions, etc., preferably hydroxide ions.

[0019] In some specific embodiments, the concentration of the selected cation in the saturated potassium chloride solution is 4.2 × 10⁻⁶. -3 ~7mol / L.

[0020] In some embodiments, the selected anion concentration in the saturated potassium chloride solution is 1×10⁻⁶. -5 ~5 mol / L, preferably 1×10 -5 ~3mol / L.

[0021] In some specific embodiments, when the saturated potassium chloride solution contains hydroxide ions, the pH value of the saturated potassium chloride solution is greater than 9.

[0022] In some specific embodiments, when the saturated potassium chloride solution contains hydroxide ions, the removal rate of octadecylamine can reach 90%.

[0023] Furthermore, when the saturated potassium chloride solution contains selected cations or sulfate ions, the removal rate of octadecylamine can reach 60%.

[0024] In some specific embodiments, the efficient removal method further includes: after removing octadecylamine from the surface, washing with saturated potassium chloride, and repeating the removal filtration and washing steps.

[0025] Furthermore, the efficient removal method further includes: dispersing the potassium chloride solid to be removed from octadecylamine in a saturated potassium chloride solution, followed by filtration and drying to obtain purified potassium chloride solid.

[0026] In one of the more preferred embodiments, a method for efficiently removing octadecylamine from a potassium chloride solid surface includes the following steps:

[0027] A certain amount of solid potassium chloride containing octadecylamine hydrochloride (i.e., industrial potassium chloride product) was placed in a washing salt solution (100 mL of saturated potassium chloride solution with a pH greater than 9 or containing a certain concentration of selected cations (lithium ions, sodium ions, magnesium ions, calcium ions, rubidium ions, or cesium ions). The solution was stirred for 1.5 h, then allowed to stand. The supernatant was removed by distillation, and 50 mL of saturated potassium chloride solution was added for washing. The above steps were repeated to remove the washing liquid. Finally, a small amount of saturated potassium chloride solution was added to disperse the solid potassium chloride in the solution. The solution was then vacuum filtered and dried to obtain purified solid potassium chloride.

[0028] Furthermore, if 100 mL of a potassium chloride saturated solution with a pH value greater than 9 is used as the washing solution in this invention, the removal rate of octadecylamine can reach 90%.

[0029] Furthermore, if a saturated potassium chloride solution containing a certain concentration of selected cations (lithium ions, sodium ions, magnesium ions, calcium ions, rubidium ions, or cesium ions) is used as the washing solution in this invention, the removal rate of octadecylamine can reach 60%.

[0030] The mechanism for removing octadecylamine in this invention lies in: adjusting the pH value of the solution to make the octadecylamine hydrochloride end group -NH3 on the surface of potassium chloride solid more responsive to the pH. + The conversion to -NH2 and the promotion of further aggregation of octadecylamine hydrochloride; when external disturbances are present in the solution, octadecylamine hydrochloride will automatically desorb from the surface of potassium chloride solid. When different types of cations are added, the cations in the solution will dope onto the surface of potassium chloride solid, replacing the positions of potassium ions, and causing crystal defects of varying degrees to form on the surface of potassium chloride crystals. The cations on the surface of potassium chloride solid are related to the hydrophilic -NH3 group of octadecylamine hydrochloride adsorbed at the chloride ion sites. + The nitrogen atom in the cation exhibits a certain attractive force, and the adsorption energy between the selected cation and the nitrogen atom is greater than that between the hydrophilic -NH2 group of the octadecylamine and the protonated H atom. + Therefore, the cations doped on the surface of solid potassium chloride tend to attract the deprotonation of octadecylamine hydrochloride and adsorb to the cation sites. Simultaneously, the cations create lattice defects on the solid potassium chloride surface, allowing octadecylamine to desorb automatically from the potassium chloride surface along with the cations when external disturbances occur in the solution. The anions, carrying two negative charges, react with the -NH3 terminal group of octadecylamine hydrochloride. + Electrostatic interaction is formed, and chloride ions are adsorbed onto the chloride ion sites on the surface of potassium chloride crystals, thereby promoting their desorption from the solid potassium chloride surface.

[0031] In summary, this invention achieves the direct removal of octadecylamine hydrochloride from solid potassium chloride by adjusting the pH value or the types and concentrations of anions and cations in the washing salt solution (saturated potassium chloride solution), without requiring a dissolution and recrystallization step, greatly reducing production costs and without introducing other organic matter.

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; all modifications conceived of or derived from the content disclosed herein are considered to be within the scope of protection of this invention.

[0033] Example 1

[0034] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a sodium ion concentration of 0.62 mol / L, stirring at room temperature and then filtering; washing with a saturated potassium chloride solution and drying at 105°C for 4 hours, the removal rate of octadecylamine in the obtained potassium chloride product is 43%.

[0035] Example 2

[0036] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a lithium ion concentration of 0.0042 mol / L, stirring at room temperature and filtering; then washing with a saturated potassium chloride solution and drying at 105°C for 4 hours, the removal rate of octadecylamine in the obtained potassium chloride product is 58%.

[0037] Example 3

[0038] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a solution with a sulfate ion concentration of 1.×10⁻⁶. -5 The product was stirred at room temperature in a saturated potassium chloride solution of mol / L and then filtered. It was then washed with a saturated potassium chloride solution and dried at 105℃ for 4 hours. The removal rate of octadecylamine in the obtained potassium chloride product was 44%.

[0039] Example 4

[0040] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a calcium ion concentration of 2.5 mol / L, stirring at room temperature and then filtering; washing with a saturated potassium chloride solution and drying at 105°C for 4 hours, the removal rate of octadecylamine in the obtained potassium chloride product is 48%.

[0041] Example 5

[0042] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a magnesium ion concentration of 0.8 mol / L, stirring at room temperature and then filtering; washing with a saturated potassium chloride solution and drying at 105°C for 4 hours, the removal rate of octadecylamine in the obtained potassium chloride product is 38%.

[0043] Example 6

[0044] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution containing hydroxide ions, wherein the pH value of the saturated potassium chloride solution is 13, stirring at room temperature and then filtering; washing with an acidic saturated potassium chloride solution and then washing with a potassium chloride solution, and drying at 105°C for 4 hours, wherein the removal rate of octadecylamine in the obtained potassium chloride product is 90%.

[0045] Example 7

[0046] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution containing hydroxide ions, wherein the hydroxide concentration of the saturated potassium chloride solution is 5 mol / L, stirring at room temperature and then filtering; washing with an acidic saturated potassium chloride solution and then washing with a potassium chloride solution, and drying at 105°C for 4 hours, wherein the removal rate of octadecylamine in the obtained potassium chloride product is 70%.

[0047] Example 8

[0048] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a cesium ion concentration of 0.01 mol / L, stirring at room temperature for 1.5 h, and then filtering; washing with a saturated potassium chloride solution, and drying at 105 °C for 4 h, the removal rate of octadecylamine in the obtained potassium chloride product is 36%.

[0049] Example 9

[0050] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a rubidium ion concentration of 0.02 mol / L, stirring at room temperature for 1.5 h, and then filtering; washing with a saturated potassium chloride solution, and drying at 105 °C for 4 h, the removal rate of octadecylamine in the obtained potassium chloride product is 20%.

[0051] Example 10

[0052] This embodiment provides a highly efficient method for removing octadecylamine from the surface of solid potassium chloride, comprising: weighing industrial potassium chloride product into a saturated potassium chloride solution with a lithium ion concentration of 7 mol / L, stirring at room temperature and then filtering; washing with a saturated potassium chloride solution and drying at 105°C for 4 hours, the removal rate of octadecylamine in the obtained potassium chloride product is 60%.

[0053] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0054] All aspects, embodiments, features, and examples of this invention are to be regarded as illustrative in all respects and are not intended to limit the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0055] The above description is merely a few embodiments of this application and does not constitute any limitation on this application. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any modifications or alterations made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A highly efficient method for removing octadecylamine from the surface of potassium chloride solid, characterized in that... include: The solid potassium chloride containing octadecylamine on its surface is immersed in a saturated potassium chloride solution containing a selected cation or anion. After thorough mixing at room temperature, the solution is filtered to remove the octadecylamine from the surface of the solid potassium chloride. The selected cation is selected from any one or more combinations of lithium ions, sodium ions, magnesium ions, calcium ions, rubidium ions, and cesium ions. The selected anion is chosen from any one or a combination of two of sulfate ions and hydroxide ions. When the saturated potassium chloride solution contains hydroxide ions, the pH value of the saturated potassium chloride solution is greater than 9.

2. The method for efficiently removing octadecylamine from the solid surface of potassium chloride according to claim 1, characterized in that: The concentration of the selected cation in the saturated potassium chloride solution is 4.2 × 10⁻⁶. -3 ~7.0 mol / L.

3. The method for efficiently removing octadecylamine from the solid surface of potassium chloride according to claim 1, characterized in that: The concentration of the selected anion in the saturated potassium chloride solution is 1×10⁻⁶. -5 ~5 mol / L.

4. The method for efficiently removing octadecylamine from the solid surface of potassium chloride according to claim 1, characterized in that, Also includes: After removing the octadecylamine from the surface, the surface is washed with saturated potassium chloride, and the steps of removal, filtration, and washing are repeated.

5. The method for efficiently removing octadecylamine from the solid surface of potassium chloride according to claim 1, characterized in that, Also includes: Disperse the potassium chloride solid (with octadecylamine removed) in a saturated potassium chloride solution, then filter and dry to obtain purified potassium chloride solid.