Methodological substantiation of the choice for optimal modes of equipment operation during the stage-wise concentrate removal in iron ores beneficiation

The urgent task of improving the quality of iron ore concentrates was studied. We propose to use the stage-wise removal of the concentrate by combining fine screening, regrinding, and magnetic-gravity separation. Exemplified by magnetite ore from the Stoilensky GOK, a scientific and methodological approach to the search for optimal separation parameters and modes was substantiated. It includes several stages: studying the particle size distribution and release of useful components in the feed product to select classification parameters; a series of experiments on grinding oversize products to diverse sizes; beneficiation of the obtained products by MG separation. To select the optimal parameters of ore preparation, an analysis of the beneficiation efficiency was used, which is calculated according to the Hancock – Luyken criterion. The results of the research are experimental dependences that connect the process parameters of beneficiation with those of fine vibratory screening. For the studied ferruginous quartzite ore processed at the Stoilensky GOK, the obtained dependences can be described by a second-order polynomial with a high accuracy of approximation. The best performance is achieved with a particle size of 0.1 mm: Fetot content in the concentrate is 69.7 %, recovery is 85 %, classification efficiency is 80.4 %. The top size of the product in this case is 0.076 mm, which corresponds to 70-73 % grinding size of –0.045 class

Registration of high-intensity electron and x-ray fields with polycrystalline CVD diamond detectors

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Zastosowanie matematycznych modeli pola w projektowaniu uzwojeń bezszczotkowych silników z magnesami trwałymi

The article presents a method for the electromotive force (EMF) determination and for correction of a connection diagram of a brushless DC (BLDC) motor winding. An appropriate mathematical field model has been proposed for this purpose. Calculation results are confirmed by experimental researches of the BLDC motor ДБ100-90-1-Р42 with an external rotor.W artykule przedstawiono metodę wyznaczania siły elektromotorycznej bezszczotkowego silnika prądu stałego, dla sprawdzenia poprawności połączeń w jego schemacie uzwojenia. W tym celu zaproponowano odpowiedni model matematyczny pola. Wyniki obliczeń numerycznych potwierdzono badaniami eksperymentalnymi bezszczotkowego silnika z wirnikiem zewnętrznym typu ДБ100-90-1-Р42

Doświadczenia z różnych metod wytwarzania bezszczotkowych silników prądu stałego o magnesach trwałych

In the paper estimation of machining influence of samariumcobalt permanent magnets on the aircraft brushless DC electric motor parameters is carried out. As a result of machining of permanent magnets in magnetized state, the experimental confirmation of deteriorating of the brushless DC electric motor parameters was received.Przedstawiono wyniki analizy i badań dwóch egzemplarzy takiego samego bezszczotkowego silnika prądu stałego wykorzystywanego w technice lotniczej. W pierwszym z nich wirnik z magnesami był poddawany obróbce mechanicznej po namagnesowaniu. W drugim – magnesowanie nastąpiło dopiero po obróbce mechanicznej. Wyniki analizy i badań wskazują na znaczne osłabienie strumienia magnetycznego w wyniku obróbki, a więc w konsekwencji znaczne pogorszenie właściwości i charakterystyk silnika