Application of Magnetic and Ultrasonic Methods for Determining Parameters of Ferromagnetic Components in Iron Ore Slurry Flows

The article considers the method for controlling the ferromagnetic component content in slurry flow by ultrasonic and magnetic measurements. One of the basic factors determining the efficiency of magnetic separators at iron ore concentration plants is the quality of distribution of the ground ore into the product containing the ferromagnetic component and the waste rock. Due to the fact that in most cases, magnetic separators extract minerals with strongly magnetic properties, it is essential to find the magnetic component content in the input ore and products of its distribution in order to improve control over the technological process. Currently, low accuracy and reliability make existing means of operative control over the ferromagnetic component content in the slurry flow inefficient. Density of slurry is one of the primary disturbing factors affecting the accuracy of measurements, and this fact determines the necessity of measuring this parameter while controlling the ferromagnetic component content. Combined methods of measurements are a promising trend in designing sensors of useful component content in the slurry flow. The article describes the method for controlling the ferromagnetic component content in slurry flow by ultrasonic and magnetic measurements.

Computational Fluid Dynamics Modelling of Liquid–Solid Slurry Flows in Pipelines: State-of-the-Art and Future Perspectives

Slurry pipe transport has directed the efforts of researchers for decades, not only for the practical impact of this problem, but also for the challenges in understanding and modelling the complex phenomena involved. The increase in computer power and the diffusion of multipurpose codes based on Computational Fluid Dynamics (CFD) have opened up the opportunity to gather information on slurry pipe flows at the local level, in contrast with the traditional approaches of simplified theoretical modelling which are mainly based on a macroscopic description of the flow. This review paper discusses the potential of CFD for simulating slurry pipe flows. A comprehensive description of the modelling methods will be presented, followed by an overview of significant publications on the topic. However, the main focus will be the assessment of the potential and the challenges of the CFD approach, underlying the essential interplay between CFD simulations and experiments, discussing the main sources of uncertainty of CFD models, and evaluating existing models based on their interpretative or predictive capacity. This work aims at providing a solid ground for students, academics, and professional engineers dealing with slurry pipe transport, but it will also provide a methodological approach that goes beyond the specific application.

Development of Resonant Density Meter and Its Application in Tailings Backfilling

To solve the problems of low measurement accuracy, poor safety, and stability of the traditional pipeline liquid density meter, a MIMR-XZ6 pipeline liquid density meter was designed based on the vibration mathematical model of fluid flowing through the pipeline. The pipeline liquid densitometer mainly consisted of a vibration tube for the liquid passing by, a distributed inductance encircled around the inner wall of the vibration tube, a resistor, and a capacitor, respectively, connected to both ends of the inductance, and the inductor, resistor, and capacitor formed the RLC series resonant circuit; an excitation signal source which could generate an alternating current (AC) voltage signal in different frequencies was applied to both ends of the RLC series resonant circuit, and the AC voltage signal was connected to the series branch formed by the inductance and the capacitor to capture the electrical signals. In view of the practical application of this liquid pipe densitometer in tailings backfilling, the installation method of the liquid pipe densitometer is flexible, and the slurry flows in a fluent and stable manner, meeting the measuring requirement of the resonant concentration analyzer. The MIMR-XZ6 pipeline liquid densitometer was used for online detection of ore pulp density, and the precision of this densitometer met the needs of industrial applications.

Parametric study of the $${\beta }$$-$${\sigma }$$ two-fluid model for simulating fully suspended slurry flow: effect of flow conditions

As proven in a recently published paper [Messa GV, Matoušek V (2020) Analysis and discussion of two fluid modelling of pipe flow of fully suspended slurry. Powder Technol 30:747$$-$$ - 768.], the $$\beta$$ β -$$\sigma$$ σ two-fluid model is capable of accurately reproducing the main features of turbulent, fully-suspended slurry flows in horizontal pipes provided that suitable values of the two parameters $$\beta$$ β and $$\sigma$$ σ are chosen. At present, the case-specific nature of $$\beta$$ β and $$\sigma$$ σ and their lack of a clear physical meaning are the main obstacles that must be overcome to give the $$\beta$$ β -$$\sigma$$ σ two-fluid model value not only as interpretative tool, but also as a predictive one. An important preliminary step to achieve this goal is to disclose the mathematical essence of the $$\beta$$ β -$$\sigma$$ σ two-fluid model, namely, to interpret the fluid-dynamic solution on the grounds of the structure of the differential and discretized equations. Such a methodological approach is applied here to the benchmark case of turbulent slurry flow between two infinite, horizontal, parallel plates, focusing, in particular, on the influence of the bulk-mean velocity of the slurry and the volumetric concentration of the solids in the flow. The study provides not only deeper insight into the $$\beta$$ β -$$\sigma$$ σ model, but also indicates important implications for alternative two-fluid models.

Validation of friction factor predictions in vertical slurry flows with coarse particles

The paper presents validation of a mathematical model describing the friction factor by comparing the predicted and measured results in a broad range of solid concentrations and mean particle diameters. Three different types of solids, surrounded by water as a carrier liquid, namely Canasphere, PVC, and Sand were used with solids density from 1045 to 2650 kg/m3, and in the range of solid concentrations by volume from 0.10 to 0.45. All solid particles were narrowly sized with mean particle diameters between 1.5 and 3.4 mm. It is presented that the model predicts the friction factor fairly well. The paper demonstrates that solid particle diameter plays a crucial role for the friction factor in a vertical slurry flow with coarse solid particles. The mathematical model is discussed in reference to damping of turbulence in such flows. As the friction factor is below the friction for water it is concluded that it is possible that the effect of damping of turbulence is included in the KB function, which depends on the Reynolds number.