Other physical and chemical methods

Next to simple chemical analysis two other methods do exist with which the nature of a feed phosphates can be defined which can attribute to assess the correct biological value of a feed phosphate.

Thermo Gravimetric analysis

With this method the mass (weight) is measured in function of the temperature. With this method the composition of a feed phosphate can de assessed.

X-ray diffraction

This method is the only technique available in which both qualitative and quantitative information regarding the presence of compounds in an unknown mixture is given.

Certainly when producing mineral mixtures other characteristics then only chemical of feed phosphates are important, like the reactivity, the capacity to absorb molasses and the easiness of wearing off the granules.

pH measurement

Determine the acidity or alkalinity of a product in a 1% or 10% solution by using a pH-meter with a pH selective electrode.

Buffer capacity

The buffer capacity or acid binding capacity signifies the milliequivalents (meq) of H+ that are fixed by the product at pH=3

Reactivity measurement

The reactivity of a product towards another product can be measured by follow-up of the temperature increase

Molasses absorption

The method for the determination of the molasses absorption is derived from the oil absorption test for pigments and extenders.

Friability of granules

The granule strength was determined gravimetrically after sieving  the granules from a friability test in a rotating funnel.

Free flowing test of powders

The flowability of powders is determined by measurement of different indices as described by CARR for the characterization of bulk solids.

Heat of hydratation

The heat of hydratation is measured by a calorimetric instrument when water is added to the product.