Search results
Results From The WOW.Com Content Network
In chemistry, fractional crystallization is a stage-wise separation technique that relies on the liquid–solid phase change. This technique fractionates via differences in crystallization temperature and enables the purification of multi-component mixtures, as long as none of the constituents can act as solvents to the others. Due to the high ...
Crystallization is the process by which solids form, where the atoms or molecules are highly organized into a structure known as a crystal.Some ways by which crystals form are precipitating from a solution, freezing, or more rarely deposition directly from a gas.
Processes are often classified according to the particular properties they exploit to achieve separation. If no single difference can be used to accomplish the desired separation, multiple operations can often be combined to achieve the desired end. With a few exceptions, elements or compounds exist in nature in an impure state. Often these raw ...
Hot filtration, solution contained in the Erlenmeyer flask is heated on a hot plate to prevent re-crystallization of solids in the flask itself. There are several laboratory filtration techniques depending on the desired outcome namely, hot, cold and vacuum filtration. Some of the major purposes of obtaining the desired outcome are, for the ...
It is a type of fractional crystallization. The process generally involves taking a mixture of substances, dissolving them in warm water, and then rapidly cooling the mixture. The insoluble compounds precipitate out of the water, while the soluble ones stay dissolved. The solution can then be separated by filtration or decantation.
Fractional freezing is a process used in process engineering and chemistry to separate substances with different melting points. It can be done by partial melting of a solid, for example in zone refining of silicon or metals, or by partial crystallization of a liquid, as in freeze distillation, also called normal freezing or progressive freezing.
The volume ratio between the first and second solvent is critical. A higher ratio of first to second solvent will lead to permanent dissolution of the desired product, while a low ratio will lead to minimal pure crystal recovery. The terms first and second are in reference to crude product soluble and crude product insoluble solvents respectively.
In the simplest case, filtration is achieved when the pores of the membrane are smaller than the diameter of the undesired substance, such as a harmful microorganism. Membrane technology is commonly used in industries such as water treatment, chemical and metal processing, pharmaceuticals, biotechnology, the food industry, as well as the ...