Modern practice of laboratory flotation testing for flowsheet development – A review

Improving the representation of hot flotation testing through the application of a novel, double batch flotation machine

This work focused on the development and evaluation of ANN-based techniques for the predictive maintenance of a reciprocating compressor. Predictive maintenance, PdM entails minimizing unplanned downtime while extending the life of the equipment through smart monitoring and analysis to predict impending failure. The predictive power of ANN has been exploited in this study to shift from reactive approaches towards maintenance to proactive ones, with improved operational efficiency costeffectively. Operations data over three consecutive months were retrieved and utilized to train the model. The model iterated through the steps of forward propagation, computation of the loss, and back-propagation to optimize the weights and biases using the training data. From this, it was observed that the ANN model was very effective in identifying the failure conditions at which compressors will fail, with an average of 98% on all predicted cases. The model's robustness is underlined by the high value of precision, recall, and F1-scores it returns; hence, it can be relied upon for failure prediction. Among those that were advisable in boosting the model were regularization, cross-validation, optimization of hyper-parameter, augmentation of data, and simplification of the model. The new direction that this study gives to failure prediction in compressors, especially the reciprocating ones, has performed impressively by showing how much machine learning and neural networks can contribute to industrial predictive maintenance

Microbeam x-ray fluorescence spectrometry was applied to the quantitative elemental mapping of elements and to the examination of the homogeneity of the elemental distribution in polymer samples. The measurements were performed with an energy-dispersive x-ray fluorescence microbeam spectrometer utilizing capillary optics. The spatial resolution of the spectrometer set-up was about 50 µm. To obtain the local concentrations of elements in polymer foils, a method employing scattered primary radiation from an Mo x-ray tube was utilized. Also, a procedure was developed to characterize, in a quantitative way, the homogeneity of the distribution of the element admixtures introduced into the polymer matrix. This procedure allows the estimation of a minimum representative sample mass, which has to be considered in order to perform a bulk analysis of a given element. Copyright © 1999 John Wiley & Sons, Ltd.

<p>The study of intrusive igneous rocks can provide insights into deep crustal processes. In active intraoceanic arc environments, the opportunity to study of these intrusive igneous rocks usually comes from xenoliths entrained within eruptive products, as accessibility to in situ intrusive rocks is limited. This thesis documents a suite of the first intrusive samples dredged from the Havre Trough, which provide insights into deep magmatic processes in this intraoceanic back-arc system. The suite of ten intrusive igneous rocks were dredged from Basin E, a back-arc basin (BAB) in the Kermadec Arc-Havre Trough (KAHT) and consist of in situ gabbroic meso- to orthocumulates. Four representative samples were selected from the suite of ten on the basis of grainsize, and from them a petrogenetic model was built to determine the associations of the samples within the magmatic system of the region. The four samples all exhibit comparable mineral assemblages of plagioclase, clinopyroxene, and magnetite, with olivine and orthopyroxene absent. Texturally the samples appear to have formed in (a) magma chamber(s) where the minerals cooled slowly and formed relatively large, euhedral crystals that trapped interstitial melt between them. The interstitial melts crystallised forming more evolved intercumulus material (plagioclase + quartz ± amphibole ± apatite). Three of the four samples have coarser grainsizes (1-2 mm), and exhibit similar magnetite temperature estimates, indicating that they formed from similar melts. The other sample has a finer grainsize (<1 mm), and exhibits lower temperature estimates, indicating that this sample formed from a lower temperature, faster cooling melt. Plagioclase compositions follow a similar trend to plagioclase phenocrysts from modern back-arc volcanoes which indicates that these samples have an association with the modern magmatic system rather than the now extinct Miocene (Colville) Arc. Clinopyroxene trace element data are also consistent with these samples being associated with the modern subduction system. The magma chamber(s) that the samples formed in, comes from a mid-lower crustal depth, 3-6 km based on pressure estimates from amphibole crystal chemistry. The exposure of rocks from this depth would have been facilitated by normal faulting associated with rifting and opening of the Havre Trough. Petrologic and geochemical analyses of these cumulates suggest that the deep, back-arc basins consist of entirely new magmatic material formed from BAB volcanism, with no evidence for pre-existing crust.</p>

A goal-oriented characterization of urban waste

The article summarizes the results of sociological research of ethnographic nature concerning description of modern behavioral practices of men who have sex with men (MSM). Reconstruction of prevalent behavioral practices of MSM carried out on the basis of evidence of the representatives of the national MSM community for their further consideration in the context of priority setting and strategy improvement of prevention programs for MSM.

The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eleventh quarter, dry thermal oxidation tests were done on coal samples from the Pennsylvania State Coal Bank. As-received and oxidized coal samples were studied by ion-exchange methods to determine the carboxylate and phenolic group concentrations. Film flotation tests were done to characterize the flotability of as-received and oxidized coals. In addition, electrokinetic tests were done on different coals, to obtain information pertinent to the selection of flotation reagents. DRIFT analysis was done to characterize the structure of coals.

The history of the metallurgical industry is rich with data. An enormous amount of data is generated from mining operations and industrial factories, and as deployment of new technologies such as on-line monitoring and in-situ instrumentation proliferate through the 4th industrial revolution, the quantity and quality of data will increase dramatically. The first paper (Part I), describes a range of promising technologies that integrate well with existing mineral processing plants and testing laboratories to demonstrate the enormous potential of a dry laboratory. A dry lab is a type of laboratory that includes applied or computational mathematical analyses for an extensive range of different applications. In both laboratories and mineral processing plants, integration of timely, accurate and reliable data analytics is key to leveraging data to enable data-driven plant design, optimisation and monitoring. However and despite progresses in analytical technology and increasing availability of data and sophisticated data analytics, legacy metallurgical plant and test work data are being underutilised. Understanding the insights contained within legacy metallurgical plant data is critical to the transition into a data- and analytics-driven industry. This paper (Part II) details two case studies that use legacy data to benefit metallurgical processes. One case study focuses on operational data from a gold recovery plant and provide indirect knowledge of the structure and/or composition of the feed sources, and insights to guide the optimisation of the operation. The other case study focuses on laboratory flotation tests, and demonstrates the effectiveness of aggregated data in establishing empirical guidelines that can guide the design and optimisation of new and existing processing operations.

The efficiency of froth flotation, a cornerstone of modern mineral processing, depends strongly on the chemistry of frothing agents that regulate froth formation, stability, and dynamics. This study investigates the effect of frother type and dosage on froth height, stability, bubble morphology, and flotation kinetics through laboratory-scale and industrially relevant experiments. A set of frothers, including conventional methyl isobutyl carbinol (MIBC) and advanced reagents such as T-92, Penoflot-1304, TPM, DF-1012, and three composite formulations, were systematically evaluated. Surface tension measurements, critical coalescence concentration (CCC) analysis, and pendant-drop techniques were applied to characterize physicochemical properties, while chalcopyrite flotation tests provided kinetic data and recovery profiles. Results revealed clear structure–property–performance relationships. MIBC promoted rapid froth generation but limited stability, whereas complex reagents such as DF-1012 and TPM produced highly stable froths with persistent fine bubbles. Kinetic modeling showed that composite frothers, particularly Composition-3, markedly enhanced chalcopyrite recovery, achieving flotation rate constants up to 0.24 min⁻¹ compared with 0.10 min⁻¹ for MIBC. In addition, economic and environmental assessments indicated that novel frothers can lower reagent consumption while improving selectivity and sustainability. Overall, this study establishes a direct link between frother chemistry and froth layer dynamics, providing practical guidelines for reagent selection in sulfide ore flotation. The findings not only improve metallurgical performance but also highlight pathways toward more sustainable and environmentally responsible mineral processing.

This study was designed to examine the extent to which relationship marketing approach of the oil firms: Shell BP, Agip Oil Company, and Elf Oil Firm have reduced the trend of oil pollution crisis in Niger Delta. A descriptive survey research design was employed in this study. The study population was 37,965,391 residents drawn from the projected population of Niger Delta states; based on which a sample size of 400 respondents was determined using Taro Yamane’s sample size determination techniques at 0.5 percent level of significance. The purposive sampling procedure was employed to enable the researcher to select the representative sample elements of the population interest from the right respondents who have adequate knowledge of the study under investigation from the different strata of the study population. A structured instrument for data collection containing twenty (20) item questions was used for the study. The face and content validation of the instrument was obtained through the judgment of experts. A test-retest method was employed to determine the reliability of the instrument and the reliability index of .85 was obtained with the use of Spearman’s Rank correlation co-efficient. The data collected for the study were analyzed using the mean score test and the percentage test method to answered the research questions; while the inferential statistics of Pearson Moment Correlation test was used to test the null hypothesis at .05 level of significance. Results obtained revealed that “There is no significant relationship between the use of adaptive, responsive, interactive and reactive relationship marketing approach and the reduction in oil pollution crisis in Niger Delta”. The implication of this finding is that the oil firms’ by its relationship marketing approach was considered to lack merit of proactive improvement value to reduce the trend of oil pollution crisis, which if, not corrected with an ethical relationship based marketing consideration in a responsible manner; oil firms might experience sudden unpredicted operational interruption by the oil-bearing communities. It was recommended that oil firms should consider using more pragmatic sustainable ethical based relationship marketing approach in a responsible manner to reduce the trend of oil pollution crisis in oil-bearing communities in Niger Delta.

Several sampling techniques were evaluated to recover representative core samples from the ash ponds at Western Kentucky Energy's Coleman Station. The most successful was a combination of continuous-flight augers and specially designed soft-sediment sampling tubes driven by a Hammerhead drill mounted on an amphibious ARGO vehicle. A total of 51 core samples were recovered and analyzed in 3 ft sections and it was determined that there are 1,354,974 tons of ash in Pond C. Of the over 1.35M tons of ash present, 14% or 190K tons can be considered as coarse (+100 mesh). Pond C contains approximately 88K tons of carbon, nearly half of which is coarse and potentially recoverable with spiral concentration while the fine carbon (-100 mesh) is recoverable with froth flotation. There are 1.27M tons of carbon-free ash, 12% of which is coarse and potentially usable as block sand. Spiral concentration testing on bulk samples showed that product grade of 30 to 38% C (4200 to 5500 Btu/lb) was obtainable. When this product was cleaned again in an additional stage of spiral concentration, the product grade was improved to 7200 to 8200 Btu/lb with an accompanying 13 to 29% decrease in yield. Release analysis of hydraulically classified pond ash showed that froth flotation could provide froth products with as high a grade as 9000 Btu/lb with a yield of 5%. Increasing yield to 10% reduced froth grade to 7000 Btu/lb. Batch flotation provided froth grades as high as 6500 Btu/lb with yields of 7% with 1.5 lb/ton SPP and 1 lb/ton frother. Column flotation test results were similar to those achieved in batch flotation in terms of both grade and yield, however, carbon recoveries were lower (<70%). High airflow rate was required to achieve >50% carbon recovery and using wash water improved froth grade. Bottom ash samples were recovered from each of the units at Coleman Station. Characterization confirmed that sufficient quantity and quality of material is generated to produce a marketable lightweight aggregate and recover a high-grade fuel product. Spiral concentration provided acceptable grade lightweight aggregate with yields of only 10 to 20%. Incorporating a sieve bend into the process to recover coarse, porous ash particles from the outside race of the spirals increased aggregate yield to as high as 75%, however, the carbon content of the aggregate also increased. An opening size of 28 mesh on the sieve bend appeared to be sufficient. Lightweight concrete blocks (28 to 32 lbs) were produced from bottom ash and results show that acceptable strength could be attained with a cement/concrete ratio as low as 1/4. A mobile Proof-of-Concept (POC) field unit was designed and fabricated to meet the processing objectives of the project. The POC plant consisted of two trailer-mounted modules and was completely self sufficient with respect to power and water requirements. The POC unit was hauled to Coleman Station and operated at a feed rate of 2 tph. Results showed that the spirals operated similarly to previous pilot-scale operations and a 500 lb composite sample of coarse carbon was collected with a grade of 51.7% C or 7279 Btu/lb. Flotation results compared favorably with release analysis and 500 lbs of composite froth product was collected with a grade of 35% C or 4925 Btu/lb. The froth product was dewatered to 39% moisture with vacuum filtration. Pan pelletization and briquetting were evaluated as a means of minimizing handling concerns. Rotary pan pelletization produced uniform pellets with a compressive strength of 4 lbf without the use of any binder. Briquettes were produced by blending the coarse and fine carbon products at a ratio of 1:10, which is the proportion that the two products would be produced in a commercial operation. Using 3% lime as a binder produced the most desirable briquettes with respect to strength, attrition and drop testing. Additionally, the POC carbon products compared favorably with commercial activated carbon when used for removal of mercury from simulated flue gas. A business model was generated to summarize anticipated costs incurred during the first year of operation of a 50 tph feed capacity plant. Using the best available data from a variety of sources, the business model showed that even when using conservative pricing and sales volume, the processing plant would be economically viable in the first year of operation. Not surprisingly, economic success would be sensitive to sales volume and pricing. In order to maximize both of these factors, it is imperative that high quality products be produced.

The purpose of the study is to evaluate the modern public spaces of the suburbs of Kyiv on the example of the village of Kotsiubynske, Buchanskyi district, Kyiv region, and to formulate practical recommendations for the development of community centers in the village. Methodology of work. The research involves the presence of theoretical and applied blocks. The first is aimed at defining the essence of the suburb as a modern dominant type of suburban spaces of large cities, researching the theory and methodology of transformations of suburban spaces, the formation of public centers, the evolution of their function, weight, etc. The application block provides a description of modern practices of the suburban lifestyle of residents on the example of the village of Kotsiubynske, an assessment of the results of a sociological survey regarding the prospects for the transformation of public spaces in the village. The research is based on general scientific methods, namely, analysis and synthesis, descriptive, analytical methods. Among the special methods, the method of comparative geographical analysis, cartographic, sociological (survey method) were used. Scientific novelty. The essence and content of the concept of public spaces are highlighted, their structural forms and types are defined, the general requirements for planning decisions of public centers are considered, the public centers of the village of Kotsiubynske, Buchanskyi district, Kyiv region are defined and characterized, and their transformations are revealed on the basis of the conducted monitoring studies of self-organization on the suburb level. Practical meaning. The research has a clearly delineated applied nature, since the results of the work form proposals for the transformation of each public space of the city from the standpoint of its importance for the residents of the village, comfort and accessibility.

Recent Advances in the Freeze-Drying of Food Products

Digital transformation is the basis of Ukraine’s war tactics. The aim is to analyze the practice and context of the evolution of informatization of education, the contribution and focus on educational technologies of distance learning in the languages of war. The method of sociological research of open primary collection of information in Kamyanets-Podilsky Ivan Ohienko National University, Volodymyr Vynnychenko Central Ukrainian State Pedagogical University, and the National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, described the problems of organization, forms, and tendencies of the educational process. The novelty - is the allocation of operational algorithms in the field of distance learning technologies, which allow teaching and supporting the participants of the educational process under conditions of armed Russian aggression. Practical significance - the analysis of the dynamics of development of informatization of society in modern conditions; in the search for digital transformations and updating of education during the war; in the description of modern practices and vectors of development. The results revealed: that educational trends in zones or without hostilities, indicators of technical development in conditions of war, and levels and principles of development of public informatization. In war conditions the educational institutions technically coped with the emergency situation.

The article explores some recurring features found in Pathé’s Italian-French co-productions in the 1950s and 1960s, addressing this corpus of films as a representative sample of the larger co-production trends between the two countries in the period under discussion. The analysis is based on the examination of unpublished documents as well as press material from the archives of the Fondation Seydoux-Pathé (Seydoux-Pathé Foundation) and the Cinémathèque française (French Film Library). As the article evidences, co-productions served as a powerful instrument of transnational cultural exchange, modern marketing practices, and the rethinking and revisiting of country-specific genres. They also paved the way for the exportation and popularization of Italian actors, directors and cinematic style across France. Great attention is paid to how the French specialist and popular press received such co-productions, whether the films’ dual nationality affected their reception and to what extent co-productions contributed to the image of Italian cinema in post-war France.