Crystallography In Farming

The crystallization of fertilizers, soil conditioners and other agrochemicals must be performed to higher degrees of accuracy now new quality-control measures are in effect.

- EVAPORATION AND CRYSTALLIZATION PROCESS UTILIZED FOR FERTILIZER PRODUCTION

This follows Veolia Water's 2012 contract with the Spanish company Iberpotash for another large-scale system that will produce 750,000 tons of purified salts and extract 50,000 tons of potash annually.

With more than 800 HPD evaporation and crystallization systems in over 30 countries, Veolia Water has proven expertise in recovering this type of material and capabilities to manage large projects of this kind. Its commitment to energy and water conservation also contributed to K+S Potash Canada GP's selection of Veolia Water.

COMMENT ABOUT THIS PROJECT:

"This latest contract with K+S Potash Canada GP confirms the potential of Veolia's HPD evaporation and crystallization technologies. With HPD technologies, we have one of the strongest offers in a market where clients expect solutions that will enable them to produce the highest quality product as cost-effectively as possible. I'm proud to say that this is the largest industrial contract signed by our Veolia Water Solutions & Technologies subsidiary to date, anywhere in the world."

Jean-Michel Herrewyn

Chief Executive Officer

- DEVELOMENT OF ARTIFICIAL SEED CRYSTAL FOR CRYSTALLIZATION OF CALCIUM PHOSPHATE

An artificial seed crystal material consisting of calcium silicate hydrate (5CaO x 6SiO2 x 5H2O : tobermorite crystals) applicable for phosphorus removal by crystallization was developed. Card-house shaped tobermorite crystals were developed on the seed material where orthophosphate crystallized as a calcium phosphate. The seed material can be manufactured by mixing siliceous and calcareous raw materials, pelletizing and subsequent autoclaving. Laboratory experiments were conducted to apply the new developed seed crystal material in the phosphorus recovery from sludge side streams of a wastewater treatment plant. In this crystallization process, the performance the carbon dioxide degassing process usually carried out when applying crystallization was not necessary, the hydroxyapatite was able to crystallize at a pH of 8.0 to 8.5 without precipitation of calcium carbonates. In the treatment of a side stream with orthophosphate concentrations of 50 mgl(-1) and COD concentrations between 200 to 400 mgl(-1), phosphorus removal efficiencies ranging from 75 to 85% were observed. The seed crystal material was collected after the laboratory experiments and the chemical estimation and the germination test for agricultural reuse were performed. As a result, it was shown that the hydroxyapatite precipitated

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