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Wear life of mill liners is an important parameter concerning maintenance decision for mill liners. Variations in process parameters such as different ore properties due to the use of multiple ore types influence the wear life of mill liners whereas random order of processing, processing time and monetary value of different ore types leads to variation in mill profitability. The purpose of the present paper is to develop an economic decision model considering the variations in process parameters and maintenance parameters for making more cost‐effective maintenance decisions.

Correlation studies, experimental results and experience of industry experts are used for wear life modeling whereas simulation is used for maximizing mill profit to develop economic decision model. The weighting approach and simulation have been considered to emphasize the contribution of parameters such as ore value and processing time of a specific ore type to a final result.

A model for estimating lifetime of mill liners has been developed based on ore properties. The lifetime model is combined with a replacement interval model to determine the optimum replacement interval for the mill liners which considers process parameters of multiple ore types. The finding of the combined model results leads to a significant improvement in mill profit. The proposed combined model also shows that an optimum maintenance policy can not only reduce the downtime costs, but also affect the process performance, which leads to significant improvement in the savings of the ore dressing mill.

The proposed economic decision model is practically feasible and can be implemented within the ore dressing mill industries. Using the model, the cost‐effective maintenance decision can increase the profit of the organization significantly.

The novelty is that the new combined model is applicable and useful in replacement decision making for grinding mill liners, in complex environment, e.g. processing multiple ore types, different monetary value of the ore type and random order of ore processing.

Multiple studies have illustrated that the needs of various users seeking descriptive bibliographic data for pop culture resources (e.g. manga, anime, video games) have not been properly met by cultural heritage institutions and traditional models. With a focus on manga as the central resource, the purpose of this paper is to address these issues to better meet user needs.

Based on an analysis of existing bibliographic metadata, this paper proposes a unique bibliographic hierarchy for manga that is also extendable to other pop culture sources. To better meet user requirements of descriptive data, an aggregation-based approach relying on the Object Reuse and Exchange-Open Archives Initiative (OAI-ORE) model utilized existing, fan-created data on the web.

The proposed hierarchy is better able to portray multiple entities of manga as they exist across data providers compared to existing models, while the utilization of OAI-ORE-based aggregation to build and provide bibliographic metadata for said hierarchy resulted in levels of description that more adequately meet user demands.

Though studies have proposed alternative models for resources like games or comics, manga has remained unexamined. As manga is a major component of many popular multimedia franchises, a focus here with the intention while building the model to support other resource types provides a foundation for future work seeking to incorporate these resources.

The adsorption of stearic acid molecules onto the surface of the Egyptian manganese ore (high and medium grades, H.G. & M.G.) was followed by adsorption isotherm determination and the sedimentation properties of the ore in apolar medium. It was found that the sedimentation properties depend on the adsorbed amount in the isotherm, the most stable dispersion for the ore in the organic medium was detected at monolayer surface coverage of stearic acid molecules on the surface of the ore.

Results and discussion Adsorption isotherms of stearic acid on the surface of manganese ore samples:

Highly efficient heat‐resistant paint formulations based on Egyptian manganese ore (high and medium grades) and silicon resin were prepared. The heat‐resistance efficiency as well as the physico‐mechanical properties of the painted films were evaluated. Promising results were deduced, showing that manganese ore imparts heat‐resistance protection for painted substrate up to 450°C. The anticorrosive properties of these paint formulations were moderate but their efficiency as heat‐resistant anticorrosive paints was improved by adding 1 per cent of melamine to the paint constituents.

Dolomite is of immense importance for industrial applications. It is occuring in many locations in Egypt. Complete investigation and identification of the ore has been performed via chemical analysis and spectro‐photometric measurements using X‐ray fluroscence, X‐ray diffraction and electron microscope. The X‐ray diffraction pattern indicated that Egyptian dolomite is a crystalline material and electron microscope analysis showed that it has a lameller shape. Egyptian dolomite sample was evaluated as an extender pigment according to standard international specifications and proved to be excellent one for coating applications. Surface modification of dolomite ore particles has been carried out using stearic acid in cyclohexane. The modification concerned with the determination of adsorption isotherm, sediment volume, sedimentation rate, and dispersion properties to determine monolayer surface coverage of the ore particles. The unmodified and modified dolomite samples have been incorporated in anticorrosive primer formulations. The painted films were tested and examined in the laboratory accelerated corrosion test. Promising results were achieved and the films showed high performance as efficient extender pigment for coating applications that can replace satisfactorily its similar imported pigments.

Past observers of the iron ore industry have asserted that significant economies of scale exist in the mining of iron ore which is enriched into taconite pellets. Quasi, long‐run average costs (LAC) of production are measured and used to estimate optimum scale of plant. Indeed the LAC appears u‐shaped and the minimum efficient scale of plant produces approximately 13 percent of 1987 North American output. However, because of the existing joint vertical integration and the conflicting ownership claims of the mines by the steel users, rationalization of capacity is not likely to occur.

The case presents a context of irrational pricing in a stock and demonstrates the possible role of investor heuristics operating in the financial markets. The case is ideal in a course on behavioral finance to teach topics like the limits to arbitrage or the influence of various heuristics in financial markets.

Epoxy‐pitch iron ore sealer. Secomastic Ltd. have introduced Micanox EKV, a two‐part epoxy‐pitch sealer coating which is reinforced with micaceous iron ore. It's properties include outstanding resistance to abrasion and to the long‐term effects of immersion in salt water, fresh water, alkalis and aliphatic hydrocarbons. After extensive practical trials, including tests on ocean‐going vessels extending over 3 years, the material showed no sign of breakdown or deterioration.

Silica waste fume is a byproduct produced in the manufacture of ferrosilicon. The sample, which was very fine and rich in silica, was characterized using chemical and spectrophotometric measurements (XRD and electron microscope). The silica fume was incorporated in anticorrosive paint formulations based on alkyd resin to replace partially or completely the imported diatomaceous silica. The various paint formulations were evaluated and the physico‐mechanical properties as well as the corrosion protection properties of the painted films have been studied. Promising results were achieved, which showed that silica fume can replace satisfactorily the imported diatomaceous silica from the economical and environmental points of view.