Crystallization Là Gì
Crystallization, or crystallisation, is the process of atoms or molecules arranging inlớn a well-defined, rigid crystal lattice in order khổng lồ minimize their energetic state. The smallest entity of crystal lattice is called a unit cell, which can accept atoms or molecules khổng lồ grow a macroscopic crystal. During crystallization, atoms and molecules bind together with well-defined angles to lớn size a characteristic crystal shape with smooth surfaces và facets. Although crystallization can occur in nature, crystallization also has a broad industrial application as a separation and purification step in the pharmaceutical and chemical industries.
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The choice of operating conditions during a crystallization process directly influences important hàng hóa attributes such as crystal size, crystal shape & purity. By understanding the crystallization process & choosing the right process parameters, it is possible to repeatedly produce crystals of the correct size, shape, và purity while minimizing downstream processing issues, such as long filtration times or inadequate drying.
Why is Crystallization Important?
Crystallization touches every aspect of our lives from the foods we eat and the medicines we take, to lớn the fuels we use lớn power our communities. The majority of agrochemical and pharmaceutical products go through many crystallization steps during their development & manufacture. Key food ingredients, such as lactose and lysine, are manufactured using crystallization và the unwanted crystallization of gas hydrates in deep sea pipelines is a major safety concern for the petrochemical industry.
Key Crystallization Definitions
Crystallization Crystallization is a process whereby solid crystals are formed from another phase, typically a liquid solution or melt.
Crystal Crystal is a solid particle in which the constituent molecules, atoms, or ions are arranged in some fixed & rigid, repeating three-dimensional pattern or lattice.
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Precipitation Precipitation is the process of generating solid from the solution caused by supersaturation when the concentration of the solute is higher than its solubility. This term is usually interchangeable with "crystallization", but differs in that it can also indicate the formation of amorphous (non-crystalline) solid.
Solubility Solubility is a measure of the amount of solute that can be dissolved in a given solvent at a given temperature
Saturated Solution At a given temperature, there is a maximum amount of solute that can be dissolved in the solvent. At this point the solution is saturated. The quantity of solute dissolved at this point is the solubility.
SupersaturationSupersaturationcan mean the status that the actual solute concentration is higher than the equilibrium solute concentration (solubility), or the degree of how much the concentration is higher than the solubility.
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Choose an appropriate solvent. Co90namdangbothanhhoa.vnháng considerations included how much solute can be dissolved (solubility) và how practical the solvent is to handle (safety)Dissolve the sản phẩm in the solvent by increasing the temperature until all solids of the sản phẩm are dissolved. At this moment, insoluble impurities may be filtered from the hot solutionReduce solubility via cooling, anti-solvent addition, evaporation or reaction. The solution will become supersaturated.Crystallize the sản phẩm. As solubility is reduced, a point is reached where crystals will nucleate & then grow. Highly pure hàng hóa crystals should form và impurities should remain in solution.Allow the system to lớn reach equilibrium to maximize the yield of hàng hóa solid.Filter and dry the purified hàng hóa.
