Refractory Materials are usually non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above 1,000 °F (811 K; 538 °C)。

Urea



Urea Prilled
Nitrogen:  46% min.
Moisture: 0.8% max
Biuret: 1% max.
Granulation:0.85- 2.80 mm 90 % min.
Colour:Pure White Prilled
Prilled,Free Flowing, Treated against caking, 100% free from harmful substances
Packing:In 1mt big bags or 500kg big bags

Urea is commercially produced from two raw materials, ammonia, and carbon dioxide. Large quantities of carbon dioxide are produced during the manufacture of ammonia from coal or from hydrocarbons such as natural gas and petroleum-derived raw materials. This allows direct synthesis of urea from these raw materials.
The production of urea from ammonia and carbon dioxide takes place in an equilibrium reaction, with incomplete conversion of the reactants. The various urea processes are characterized by the conditions under which urea formation takes place and the way in which unconverted reactants are further processed.

Agricultural use
Urea is used as a nitrogen-release fertilizer, as it hydrolyses back to ammonia and carbon dioxide, but its most common impurity, biuret, must be present at less than 2%, as it impairs plant growth. It is also used in many multi-component solid fertilizer formulations. Its action of nitrogen release is due to the conditions favouring the reagent side of the equilibria, which produce urea. If the group of bacteria which "burn" or oxidize urea are not present in the soil then most of the acting ingredient (nitrogen) will not be absorbed by the plants.

Industrial use
Urea has the ability to form "loose compounds", called clathrates, with many organic compounds. The organic compounds are held in channels formed by interpenetrating helices comprising of hydrogen-bonded urea molecules. This behaviour can be used to separate mixtures, and has been used in the production of aviation fuel and lubricating oils. As the helices are interconnected, all helices in a crystal must have the same "handedness". This is determined when the crystal is nucleated and can thus be forced by seeding. This property has been used to separate racemic mixtures.