Carbonate is a type of chemical compound that contains the carbonate ion, CO3. AERATE is a verb meaning to supply air or oxygen to something, and it has 6 letters. ESTER is a type of chemical compound formed by a reaction between an acid and an alcohol, and it has 5 letters. Limekilns are structures used to produce quicklime from limestone, and they have 9 letters. Natron is a naturally occurring mixture of sodium carbonate decahydrate and sodium bicarbonate, and it has 6 letters. Sal is an archaic term for salt, and it has 3 letters. ALKALI is a type of base, and it has 6 letters. Siderite is an iron carbonate mineral, and it has 8 letters. MARL is a type of soil composed of clay and calcium carbonate, and it has 4 letters.