The iron filings It is a material made up of small metallic iron particles. The particles are small enough to look like black sand, which exhibits very interesting properties in response to their interaction with a magnetic field..
Also, this sand or filing is often mixed with other substances to create what is called a ferromagnetic fluid. This behaves as if it were a porcupine or black hedgehog; or, on the other hand, if it is covered with a polymer, it gives the impression that the mass formed takes on a life of its own under the stimuli of the magnets.
The image above shows an agglomerate product of the attraction felt by iron filings towards a magnet. This property has served him to be used since time immemorial in the academy as a manifesto of magnetism; either in elementary school and in university studies.
Iron filing should be treated or viewed as another physical way of arranging the metal. Therefore, you can expect your applications to orbit around small particles, such as contaminants, in small spaces, or on large surfaces..
Article index
The properties of iron filings, coming from larger pieces of iron, are precisely the same as for metal. Some of those properties are as follows:
-It is a magnetic solid with metallic and grayish glints.
-Insoluble in water and organic solvents that do not present acidity.
-It is sensitive to oxidation if exposed to air and water for too long.
-Due to its larger surface area, it can easily ignite if it comes into contact with high temperatures..
-Its melting and boiling points are 1535 and 3000ºC, respectively..
-The density of these filings is 7.86 g / mL.
-Although it is not a physical property, the size of its particles varies depending on the method by which they are produced and how they are processed.
To make or create iron filings follow a series of relatively simple steps.
It begins with a piece of iron from which its particles will be obtained. If said piece is tubular, a milling cutter is used; and if it is flat, a radial to sand the surface, like a sheet of wood that gives off sawdust.
The particles obtained by any of the techniques or tools used in metal cutting can be of very different sizes. It is desired that the filings have only the smallest particles; therefore, they are sieved to separate the dust from larger pieces or crystals..
The more refined the sieve, the smaller the particles and the finer the filings. However, for learning purposes it is sufficient to use a typical kitchen strainer..
Finally, the iron filings are washed.
One method consists of immersing them in water and, at the bottom of the container, placing a magnet to separate the impurities from the filings so that the former remain suspended; and thus, decant with the rest of the water. This procedure is repeated several times until the filings are considered to have a sufficiently grayish color..
The disadvantage of the previous method is that the water favors the oxidation of the filings in rust.
Another method, unlike the first, uses mineral oil or glycerin. The oil helps remove rust or rust from filings by mechanical agitation. The suspension is left to rest so that the filings settle to the bottom. Once this is done, the dirty oil is decanted and the procedure is repeated several times until the filings are clean..
The advantage of using oil is that greater resistance to oxidation is guaranteed. It is also a suitable means of keeping filings in storage. When they are going to be used, they are put on absorbent paper as many times as necessary until they do not stain it.
Iron filings do not represent any danger to the body; at least, not in normal situations, and in the absence of high temperatures or chemicals that react violently with iron.
Being so small, they can easily slip through the nostrils or eyes, causing irritation. However, iron filings do not have a strong absorption into the skin, so no possible negative effects have been reported..
Iron filings are very sensitive to the magnetic field of magnets. Each iron particle behaves like a small magnet that lines up for or against the north and south poles of the central magnet..
Thus, one particle of iron attracts and repels the other, which creates characteristic circular (in paper) or spherical (in fluids such as water and oil) patterns. In the image below, for example, you can see how iron filings line up in the resulting magnetic field over the two poles of a magnet..
Even more interesting is to develop the experiment with the filings (also called shavings) immersed in a fluid. The magnet seems to have the power to give them a life of their own and the patterns obtained are more surprising.
Iron filings can have an affinity for certain compounds, which interact electronically with their metallic surface..
In this way they are able to retain, for example, phosphorus and calcium alginate biopolymers. This is done for the purpose of purifying a medium, such as a lake, of specific compounds..
Iron filings represent a different source of iron than its salts, rusts, sulfides, and other minerals. They also have the advantage of a greater surface area, which is proportional to its reactivity or addition; the latter process can be carried out, for example, by coprecipitation of iron.
A polymer can exhibit ferromagnetism or some other property if it succeeds in incorporating metallic iron into its structure from filings. However, iron nanoparticles, thousands of times smaller than filings, can easily meet this same goal..
Yet No Comments