A computer simulator for training operators of the technological process of granulating ammophos in a drum granulator dryer is considered. The technological object and the requirements for controlling the granulation process are briefly described. The functions of the simulator, the structure of its mathematical and algorithmic support are given. The software implementation of the simulator is made in the Visual Basic environment.

Keywords: computer simulator, mathematical model, algorithmic support, training of process operators, pelletizing, drum granulator dryer, granule diameter, ammophos pulp

Modern trends of the concretes studies have been considered. Properties of the materials and additives used have been cited. There has been undertaken designing an experiment on a complex modifying additive application for a fine fibre-reinforced fine-sand cocrete. The results of the studies undertaken have been analyzed with regard to their statistical significance. On the bases of the reseach results there have been acquired regression equations for objective functions responses, namely ultimate strength on both compression and bending, and average density of fine fibre-reinforced concrete. There have been produced contour plots and those of response function surface - ultimate strength under compression for all combinations of the both factors. There have been determined the composition of the modifying additive, which ensures maximal strength properties for fine fibre-reinforced fine-sand concrete.

Keywords: fine concrete, complex additive, designing an experiment, strength, regression equation, plots of response function surface

Mathematical modeling and optimization of the process of controlling the sulfate regime when the apatite load changes on the phosphoric acid extractor is considered. It is shown that the preservation of the "sulfuric acid/apatite" ratio with a sharp change in the apatite consumption leads to a violation of the technological regulations for SO3. The algorithm of correction of this ratio in the transition mode is developed, which minimizes the probability of violation of the regulatory indicators. A variant of implementing the optimal apatite load correction procedure using stand-alone scenarios is proposed. The results were confirmed during the simulation.

Keywords: algorithm, mathematical model, stabilization of the sulfate regime, extraction phosphoric acid, change in the load on the extractor, phosphorus yield coefficient from apatite, optimization, autonomous scripts

The granulation process of ammophos in a drum granulator-dryer (DGD) is considered. The main factors affecting the granulation process are considered. The inputs and outputs of the mathematical model of the granulation process are determined. A dynamic mathematical model has been developed for the formation of the equivalent diameter of ammophos granules depending on the flow rate and particle size distribution of the external recycle. Graphs of comparison of simulation results with actual data of normal operation are presented. A graph of the dependence of the equivalent diameter of the granules on the flow rate of external recycling is presented. The model is intended to create a system for stabilizing the granulation mode.

Keywords: ammophos, recycle, granulation, particle size distribution, drum granulator-dryer, modelling, mathematical model