The aim of the paper is an assessment of geometrical properties of regular and irregular particles of chalcedonite enrichment products carried out in a laboratory ring jig. The investigative program included experiments of aggregate enrichment, along with visual analyses made for the obtained products, separately for regular and irregular particles. Several shape coefficients were calculated, and the most effective ones in terms of assessment of particle regularity were selected from among them. Particle size distributions for feed and enrichment products were also determined using the idea of minimum Feret’s diameter, and the intensity of dust emission by individual products was measured as well. The results obtained by the visual system were discussed in the context of their application in the assessment of enrichment operations carried out in a water jig.
Morphological properties of mineral particles, in particular their size and shape, play a fundamental role in the course of mineral raw materials processing. They affect the efficiency of grain classification and downstream beneficiation operations. The article presents the results of the size and shape distribution for the particles after the comminution process. The measurements were made with using a vision system with dynamic image analysis. The aim of investigations was to evaluate the applicability of this technique for control of the particle size of raw material products crushed in various laboratory crushing devices.
26 September 2018 in IOP Conference Series: Materials Science and Engineering
Approximately 7 million tonnes of zinc is annually used for corrosion protection in processes of continuous galvanization and the hot dip processes. Two types of waste are obtained from the process: zinc ash and hard zinc and each of them constitute around 10% of the feed weight. Paper concerns the method of possible separation of metallic zinc from the non-metallic zinc compounds from the zinc ashes – the waste product of hot dip galvanization process. The investigative programme covered the comminution tests of the feed (zinc ash) in selected crushers: jaw crusher, roller crusher and impactor. Results of investigations show that application of individual crushing device results in various breakage of the feed sample. Impact force caused the highest increase in finest particles size fractions of the product, while metallic and non-metallic fractions were comminuted differently. The compression force, in turn, caused the selective comminution, i.e. the breakage of metallic zinc was observed in a higher degree.
This paper presents methods for modelling and optimising the industrial limestone grinding process carried out using a real limestone plant. Two key process evaluation indicators were developed: specific electric energy consumption and an extended indicator that also includes gas usage. Using process data collected from the SCADA system and results from industrial factorial experiments, regression artificial neural network models were developed, with controllable process parameters used as inputs. In the next phase, black-box optimisation was performed using Bayesian and genetic algorithms to identify optimal mill operating settings. The results demonstrate significant improvements in energy efficiency, with energy savings reaching up to 48% in selected cases. The proposed methodology can be effectively applied to enhance energy performance in similar industrial grinding processes.
26 September 2018 in IOP Conference Series: Materials Science and Engineering
The article presents the results of laboratory-scale research on the determination of the impact of ball mill parameters and the feed directed to grinding on its effectiveness and comparing it with the efficiency of grinding in a rod mill. The research was carried out for grinding copper ore processed in O/ZWR KGHM PM S.A. The aim of the research was to evaluate the efficiency of grinding in a drum mill dependably on the grinding media used (balls, rods) for various feed parameters - i.e. particle size distribution, mix of lithological type generating different susceptibility to grinding. Determination of the influence of the grinding media type on the efficiency of material grinding is of great practical importance in the designing of optimal grinding circuit. Furthermore, thanks to the acquired knowledge in this area it allows to improve the technological and economic indicators of the copper ore enrichment process. The paper presents guidelines and recommendations for conducting the grinding process of mineral raw material (copper ore) enabling the achievement of optimal technological indicators. An important practical part of the recommendation is determination of the conditions for using a given type of grinding media, such as rods or balls.