Product profiles under the Fertiliser Sector are aimed at giving an overview to readers about four major fertiliser from the fertiliser industry in India.

In this chapter, the chemicals are presented in the following order:

A. Urea

B. Diammonium Phosphate

C. Single Super Phosphate

D. Muriate of Potash

A. Urea

Urea or carbamide is a solid and highly soluble organic compound.

Uses

It is widely used as a fertiliser because of its high nitrogen content (46%). If released into water, urea is expected to be biodegraded yielding ammonia and carbon dioxide. Urea helps removing nitrogen deficiency in crops and also helps in the absorption of phosphate and potash by crop roots. Urea is ideally suitable for all types of crops including food grains (rice, wheat, maize, jawar, bajra, etc), cash crops (sugarcane, cotton, jute and fodder), fruits (apple, banana, grapes, mangoes, etc), vegetables (cauliflower, cabbage, mushroom, onion, potatoes, etc) and oil seeds (castor, cotton seeds, groundnut, mustard, etc.). Urea is also used as a raw material for the manufacture of chemicals including plastics (ureaformaldehyde resins) and adhesives (urea-formaldehyde).

Preparation Process of Urea

Urea is produced industrially from ammonia and carbon dioxide which are produced using natural gas, water and air. There is a two step process where the ammonia and carbon dioxide react to form ammonium carbamate which is then dehydrated to form urea.

Major Manufacturers of Urea

Indian Farmers Fertiliser Co-Op. Ltd, M M T C Ltd, State Trading Corpn. of India Ltd, Tata Chemicals Ltd, Rashtriya Chemicals & Fertilizers Ltd, Zuari Industries Ltd, Gujarat State Fertilizers & Chemicals Ltd, National Fertilisers Ltd, Chambal Fertilisers & Chemicals Ltd and Gujarat Narmada Valley Fertilizers Co Ltd are some of the major manufacturers of urea.

B. Diammonium Phosphate

Diammonium phosphate (DAP) is a chemical phosphatic fertiliser that is used extensively for bulk blending and for direct application in soils. It has the advantage of being highly water soluble. DAP is used as a fertiliser and also as a fire retardant. DAP is also used as a yeast nutrient in winemaking and brewing mead; as a flux for soldering tin, copper, zinc and brass, to control precipitation of alkali-soluble and acid-insoluble colloidal dyes on wool.

Production Process of Diammonium Phosphate

When phosphoric acid and ammonia are mixed a non-hazardous product diammonium phosphate (DAP) is produced. Both phosphoric acid and ammonia are generally used in large quantities and in concentrated form and if too little phosphoric acid is added, the reaction turns out to be incomplete and ammonia is produced.

Major Manufacturers of Diammonium Phosphate

Gujarat State Fertilizer & Chemicals Ltd, Indian Farmers Fertiliser Cooperative Ltd, Zuari Industries Ltd, Mangalore Chemicals & Fertilizers, Godavari Fertilizers & Chemicals Ltd, Tata Chemicals Ltd are the major manufacturers of Diammonium Phosphate,

C. Single Super Phosphate

Single Super Phosphate (SSP) is a straight phosphatic multi-nutrient fertiliser which contains 16% water soluble P2O5, 12% sulphur, 21% calcium and some other essential micro nutrients in small proportions.

Uses

SSP is also used to treat sulphur deficiency in soils as well for further enhancement of yields. SSP can be easily stored for a long period and it is one of the cheapest sources of sulphur. It acts as an essential fertiliser for various crops like oilseeds, pulses, sugarcane, fruits and vegetables and tea among others which requires more of sulphur and phosphate. As a phosphate fertiliser, SSP can be procured in two forms namely Powder Single Superphosphate (PSSP) and Granulated Single Superphosphate (GSSP). The uses of SSP are:

• Supplying plants with phosphorus, sulphur & calcium element
• Fixing plant roots in soil and helping them combat pests
• PSSP gives plants a better chance to carry out their bio-functions, such as germination, vegetation and ripeness
• GSSP can be used to fertilise desert and calcareous lands and is perfectly usable in automatic/mechanical fertilisation.

Production Process of Single Super Phosphate

Single superphosphate is produced by the reaction of phosphate rock with sulphuric acid which converts the insoluble (tribasic) form of calcium phosphate to a soluble (monobasic) form.

Major Manufacturers of Single Super Phosphate

Tata Chemicals Ltd, Rashtriya Chemicals & Fertilizers Ltd, Nirma Ltd, Jubilant Organosys Ltd, Khaitan Chemicals & Fertilizers Ltd, Maharashtra Agro-Industries Development Corporation Ltd, Rama Phosphates Ltd, Liberty Phosphate Ltd are some of the major manufacturers of Single Super Phosphate.

D. Muriate of Potash

The chemical compound potassium chloride (KCl) is a metal halide composed of potassium and chlorine. In its pure state it is odourless. It is a white to colourless vitreous crystal, with a face-centred cubic structure.

Uses

Muriate of Potash or Potassium Chloride is the most widely used fertiliser for crops with large potassium and chloride requirements such as coconut and oil palm. Potassium in plants is important for the osmotic and ionic regulation, plays a key role in the water homeostasis and is closely connected with processes involved in the protein synthesis. The chloride is also essential for the photosynthesis in plants and has important functions in osmotic regulation. An adequate supply of potassium and chloride in plants tends to improve the plant's resistance towards several diseases. As a result, correcting potassium deficiency in crops yields excellent economic returns. Other non-fertiliser uses of KCl include:

- Food & foodstuff additives: KCl is used as a nutrient and/or dietary supplement food additive. KCl also serves as a potassium supplement of animal feed
- Pharmaceutical products: KCl is used for prophylaxis and treatment of hypokalemia, in electrolyte replenishment solutions for general medical use and kidney dialysis, and in digitalis intoxication
- Laboratory chemicals: KCl is used in electrode cells, buffer solutions, and spectroscopy
- Oil industry: KCl is used as conditioner in oil drilling muds and as a shale stabilizer to prevent swelling
- Flame retardants and fire preventing agent: KCl is used as a component in dry chemical fire extinguisher
- Anti-freezing agent: KCl is used to melt ice on streets and driveways
- Flux agent for casting: KCl serves as a flux in secondary aluminium processing
- Intermediate: for basic chemicals industry.

Preparation Process of Muriate of Potash

Potassium chloride occurs naturally as sylvite and it can be extracted from sylvinite. Potassium deposits occur as beds of solid salts beneath the earth's surface and brines in dying lakes and seas. Salt lakes and natural brines represent about 10% of total recoverable potash. It is separated from crude salt by thermal dissolution, flotation and crystallisation processes that separate potassium chloride from rock salt (mostly NaCl) or Mg Cl2 or kieserite (MgSO4.2H2O). This can also be achieved by a dry process known as 'electrostatic differentiation'.

Major Manufacturers of Muriate of Potash

As there are no commercially viable sources of potash in the country the entire demand is met through imports.