Magnetic Separation of Metal-Containing MixturesIron filings mixed with sandPins mixed with marblesThumbtacks mixed with shredded paperNeedles mixed with beadsStaple wires mixed with pebblesFiltration is the process of separating solid particles suspended in a fluid (which can be a liquid or a gas) by passing the mixture through a porous material called a filter. The filter allows the fluid to pass through while retaining the solid particles, which are too large to go through the pores. The clear liquid or fluid that passes through is called the filtrate, and the retained solid is called the residue or filter cake. This process is commonly used to separate mixtures where solids do not dissolve in the fluid, such as sand from water or tea leaves from brewed tea.