A process for the preparation of a microelement deficiency corrector for farmland comprising a mixture of trace elements, in hydrated sulfate form, and containing alkaline earth carbonates or magnesite, whose essential metals are iron, magnesium, manganese and zinc and whose typical elemental analysis is the following:
- magnesium(as MgO), 3.5-4%;
- iron (as Fe II), 12-13%;
- manganese, 1-1.5%;
- zinc, 0.2%;
- and organic matter, 10%;
- said process comprising the following steps:
- (a) introducing in a mixer 50-95% of by-product from manufacturing titanium bioxide via sulfate, 5-10% alkaline earth carbonate or magnesite and, 10% of organic matter selected from manure and lignites and mixing for 5-10 minutes;
- (b) passing the mixture coming from step (a) through a grinder, where the size thereof is reduced to particles between 0 and 2 mm;
- (c) dosing the product coming from step (b) in a granulating machine where it is transformed into powder in spheres of different sizes;
- (d) passing the powder of the granulating machine to a rotary dryer with an air intake temperature between 100.degree. and 500.degree. C.;
- (e) passing the granulate coming from the dryer to a cooler from which it comes out at a temperature between 40.degree. C. and room temperature;
- (f) passing the product, once cool, through a screen which selects the granulate by sizes between 1 and 5 mm of diameter and, subsequently, packaging it;
- wherein the by-product from the manufacture of titanium bioxide via sulfate contains a mixture of metal sulfates which have the following typical elemental analysis based upon the total weight of said by-product:
- ______________________________________ *S 19% Fe 21.3% SiO.sub.2 0.06% Al.sub.2 O.sub.3 0.45% CaO 0.01% Zn 0.34% Pb 0.03% As 0.01% MgO 0.25% Mn 1.65% Cu 0.01% Sn 12 ppm Bi 1 ppm Co 40 ppm Cd 1 ppm Hg 0.01 ppm Ni 30 ppm H.sub.2 O 8.25% H.sub.2 SO.sub.4 15.1% TiO.sub.2 1.5% ______________________________________ *corresponds to sulfuric acid and sulfates.