Chapter 14 - Antifreeze Agents

Abstract

An antifreeze is defined as an additive that, when added to a water-based fluid, An antifreeze is an additive that reduces the freezing point of a water-based fluid after being added to it.. Antifreezes are used in mechanical equipment in environments below the freezing point to prevent the freezing of heat-transfer fluids. There are two different types of antifreeze chemicals—namely, liquids and salts. Liquids are miscible over the full range of concentration with water, whereas salts are soluble only to a certain amount. The common antifreeze agents in heat-transfer liquids are brine solutions and alcohols. Antifreezing agents for cement mainly include salts like calcium chloride, magnesium chloride, sodium chloride, and soda. Calcium chloride is highly corrosive and very rarely used. Some salts, especially potassium chloride, affects the curing time of cement, but are effectively used to increase the pot life of cement. Likewise, alcohol freezing-point depressants, such as ethylene glycol, can be also be added to the mixture. Antifreeze agents can also be occasionally added to reduce the freezing point of the drilling fluid itself. Such a water-based drilling fluid consists of water, clay or polymer, and a poly-glycerol. The drilling fluid helps in low-temperature drilling.