Researches of physical and chemical features of processes of complex fertilizers producing in the presence of magnesium containing components

The physicochemical laws of the producing of magnesium-containing compound fertilizers based on superphosphate production and ammonium phosphate with the involvement of the Kovdorsky apatite concentrate and various types of magnesium-contai ning raw materials are described. The influence of the main technological parameters and the optimal conditions for combined decomposition of phos-phate raw materials and technical product – dolomite, providing the producing of magnesium-containing fertilizers with specified chemical and physical properties with a content of magnesium (not more than 5 wt %) are determined. New scientific facts about the rheological properties of phosphate suspensions, intermediate and end products, produced at different stages in the suspension of complex magnesium fertilizers based on various types of magnesium containing raw materials are received. It allows the researches to define the optimal conditions and the ways of introduction of magnesium, nitrogen and potassium containing com-ponents in the technological process. The physical and chemical mechanisms are examined. The chemical transformations activity at various stages producing of complex magnesium-containing fertilizers based on magnesium digestion of phosphate raw material and/or dolomite followed by carbamide introduction, gaseous ammonia neutralization, and the addition of magnesium sulfate and potassium chloride is defined. The presented data formed the basis for developing a flexible resource-saving technology of the complex magnesium-containing fertilizers obtainment that provides the diversification possibilities, the obtainment of concentrated long-acting fertilizers with improved physical properties.