Yara International Asa

Amund Myrstad

Torstein Obrestad

Petr Chladek

Tore Frogner

Riccardo Mulato

Mari KIRKEBØEN NÆSS

Alejandro Marmolejo

The present disclosure concerns fertilizer particles comprising calcium nitrate and potassium nitrate. It is found that fertilizer particles comprising 43 to 47% w/w calcium nitrate and 46 to 54% w/w potassium nitrate can be produced by melt granulation. Due to undercooling problems, such particles were not expected to be suitable for industrial production by melt granulation. However, the present disclosure provides a composition which forms a low viscosity melt with short solidification time. This was successfully achieved by reducing the water content of a fertilizer melt comprising 43 to 47% w/w calcium nitrate and 46 to 54% w/w potassium nitrate to less than 3% w/w of the melt.

Calcium nitrate and potassium nitrate fertiliser particles

The present disclosure concerns a method for producing fertilizer particles comprising an alternative source of boron. It is found that certain colemanite and ulexite powders can be supplied to a fertilizer melt shortly before granulation essentially without dissolving into the melt. Accordingly, the fertilizer particles produced from the melt may contain negligible amounts or non-detectable levels of sodium borates or boric acid. Furthermore, the fertilizer particles can be homogeneous which is desirable for boron supplying fertilizers. It is also found that the fertilizer particles can supply boron to plants at a rate comparable to borax pentahydrate.

Method for producing fertilizer particles comprising alternative boron sources

The present invention relates to the use of a double salt of Ca(NO)and KNOfor the manufacture of a melt, in particular a nitrate-based heat transfer fluid (HTF) and/or thermal energy storage fluid, for example in solar energy applications, such as in solar electrical power plant systems using a parabolic through, a central receiver or a linear Fresnel, which have both a low melting temperature and a high decomposition temperature, as well as to methods for the manufacture thereof. Using said double salt, a melt could be manufactured comprising at least NaNO, KNOand Ca(NO), preferably, an eutectic ternary melt comprising Ca(NO), NaNOand KNOin a weight ratio of about 42:15:43 with an operating temperature of about 131&#xb0; C. to about 560&#xb0; C.

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Skien, Norway

Amund Myrstad