CHEMISTRY GLOSSARY

abrasive    →   abraziv

Abrasive is a very hard, brittle, heat-resistant substance that is used to grind the edges or rough surfaces of an object. Boron carbide, diamond, and corundum are abrasive.

ball mill    →   kuglični mlin

Ball mill is a grinder for reducing hard materials to powder. The grinding is carried out by the pounding and rolling of a charge of steel or ceramic balls carried within the cylinder. The cylinder rotates at a relatively slow speed, allowing the balls to cascade through the mill base, thus grinding or dispersing the materials.

Type of ball mills, centrifugal and planetary mills, are devices used to rapidly grind materials to colloidal fineness (approximately 1 μm and below) by developing high grinding energy via centrifugal and/or planetary action.

colloid mill    →   koloidni mlin

Colloid mills are machines used to grind aggregates into very fine particles or to apply very high shearing within a fluid to produce colloid suspensions or emulsions in which the particle sizes are less than 1 micrometer. One type of colloid mill is called a disc mill, in which a mixture of a solid and liquid (or two liquids) is passed between two discs a small distance apart, which rotate very rapidly relative to each other. Applications of colloid mills occur in food processing, in paint manufacture, and in the pharmaceutical industry.

diamond    →   dijamant

Diamond is the hardest known mineral (with a hardness of 10 on Mohs’ scale). It is an allotropic form of pure carbon that has crystallised in the cubic system, usually as octahedral or cubes, under great pressure. Diamond crystals my be colourless and transparent or yellow, brown or black. They are highly prized as gemstones, but also have extensive uses in industry, mainly for cutting and grinding tools. Diamonds occur in ancient volcanic pipes of kimberlite, or in river deposits that have been derived from weathered kimberlite. Industrial diamonds are being increasingly synthetically produced.