Reliable information on the surface state of sulphide copper minerals and regularities of sulphidization and flotation of oxidized copper minerals, the composition of sorption layer on the mineral surface forming during its interaction with xanthate or dixanthogen, and the influence of collector forms sorption on the copper minerals floatability and on the optimal conditions for these minerals flotation and depression has been obtained at present. The determined physicochemical models in the form of quantitative equations have been derived for the optimal conditions of flotation and depression of copper minerals under changing pH value and of sodium sulphide, lime, cyanide, zinc–cyanide complexes additions. The equations derived were proven in the laboratory and industrial scale and can be used both in automatic control systems at plants and for improvement of technological processes of selective flotation of copper containing ores.

Physical characteristics of mineral aggregates (such as density, size, shape, structure and strength) formed by either electrolytic coagulation or polymeric flocculation, need to be critically controlled by optimum conditioning in mineral processing. The present paper discusses the various experimental techniques used to determine these properties. In addition, physical and chemical factors that determine the rates of floe growth and which subsequently influence the floe morphology are summarised. This review also elucidates the hydrodynamic aspects of creeping flow and summarises the various settling velocity equations pertaining to the calcuation of floe density.

Graphite as the most common polymorph of naturally occurring crystalline carbon is required for many different applications such as batteries, refractories, electrical products, and pencils. Graphite resources are currently being subjected to intensive exploration to help meet rapidly growing global demand – and graphite has made it onto the list of critical raw materials as issued by the European Union. Graphite ore is mostly beneficiated using flotation separation techniques. The increasing demand for high-grade graphite products with up to 99.99% carbon has resulted in the development of various approaches to remove impurities even to parts per million range. This paper considers separation and purification techniques that are currently employed for graphite mineral beneficiation, and identifies areas in need of further research.

It is well documented that chemical additives (grinding aid “GA”) during grinding can increase mill throughput, reduce water and energy consumption, narrow the particle size distribution of products, and improve material flowability. These advantages have been linked to their effects on the rheology, although there is a gap in understanding GA effectiveness mechanism on the flow properties. The present study aims to fill this gap using different GAs (Zalta™ GR20-587, Zalta™ VM1122, and sodium hydroxide) through batch grinding experiments of magnetite ore and addressing the mechanisms of their effects on the rheology by an FT4 Powder Rheometer as a unique system. Experimental results showed that GA improved grinding efficiency (energy consumption and product fineness), which were well-correlated with basic flow energy, specific energy, aerated basic flow energy, and aerated energy. Moreover, the rheometry measurement showed strong linear correlations between basic flow energy, specific energy, and the resulting work index when GAs was considered for grinding, which confirmed the effect of GA on ground particles’ flowability. Zalta™ VM1122, a polysaccharide-based grinding aid, showed the best performance with 38.8% reduction of basic flow energy, 20.4% reduction of specific energy, 24.6% reduction of aerated basic flow energy, and 38.3% reduction of aerated energy. It also showed the strongest correlation between the grinding parameters and flow parameters (r > 0.93). The present investigation shows a strong indication that the predominant mechanism of GAs is based on the alteration of rheological properties and identify Zalta™ VM1122 as the best GA.

Coal continues to play a major role in the economic development of a country, especially in metallurgical industries and conventional power generation plants. For effective utilization of high ash coals, it is necessary to beneficiate them. The wet beneficiation process for coal cleaning is currently the predominant method of purification of coal in the world. However, dry beneficiation of coal has obvious advantages over wet processes. The dry processes for coal are based on the physical properties of coal and its associated mineral matters. Different types of equipment for dry beneficiation have been developed, based on the exploitation of physical properties such as density, size, shape, magnetic susceptibility, and electrical conductivity. This article presents a summary assessment of different technologies and their performance in the beneficiation process of high ash coals with particular reference to Indian thermal coals. The literature on sorting, air jigs, magnetic separation, air-dense medium fluidized bed separation, and electrostatic separation is summarized and discussed

Metal accounting is becoming an area of growing focus because of the requirement for the resulting data to feed directly into financial reports. It is vital in the fulfillment of best corporate governance practices and to provide assurance on metallurgical processes. The current metal accounting practices deliver a number of important measures, but an essential change in the approach toward data integrated and auditable metal accounting system is an indispensable need. This work aims to present a systematic framework toward a highly reliable method in mental accounting. The proposed approach introduces a novel mining to product metal accounting scheme and conceptualization of an intelligent metallurgical and metal accounting information management system (MMAIMS). An open cast gold mine in South Africa is presented as a case study. Based on the results and discussions that we have presented in this study, it has been shown that the proposed intelligent MMAIMS will result in improved plant process control, transparent financial reporting, and a suitable understanding of interrelationships between different process activities. The intelligent MMAIMS approach will eradicate data security risks related to multiple-user environment spreadsheets, create reliability in data used for decision-making and operation data synchronization. End to end metal accounting process visibility across the whole process will advance the audibility and transparency of metal accounting from mine to product, and enable good corporate governance and financial reporting of the salable metal product concerning smart mining and mineral processing concept.

The influence of major components of calcium and sulfate ions in process water on xanthate collector adsorption and flotation response of pure chalcopyrite, galena, and sphalerite minerals was investigated by Hallimond tube flotation, zeta-potential, FTIR, and XPS spectroscopy studies, while bench scale flotation tests were also carried out using complex sulfide ores. Marginally lower recoveries of chalcopyrite and galena in process water and in the presence of calcium and sulfate ions in both deionized and process waters using potassium amyl xanthate as collector were observed in Hallimond tube flotation, whereas sphalerite floatability is a little increased in process water using isobutyl xanthate as collector. Zeta-potential results show the adsorption of calcium ions on the minerals. FTIR and XPS studies revealed the presence of surface oxidized sulfoxy species and surface calcium carbonates and/or calcium sulfate on chalcopyrite and galena in the presence of process water and water-containing calcium ions at flotation pH 10.5, and these surface species influenced xanthate adsorption. Surface-oxidized sulfoxy and carbonate species were seen on sphalerite surface in the presence of deionized water, process water, and water-containing calcium and sulfate ions at pH 11.5, but the surface species does not influence xanthate adsorption. Bench scale flotation using two different complex sulfide ores showed that chalcopyrite, galena, and sphalerite recoveries are higher in process water than tap water and general decrease of the minerals floatability at temperatures lower than 22°C in either tap water or process water

Froth flotation is the most preferred processing technique for the enrichment of low-grade sulfides. Bioleaching is an eco-friendly method for metallurgical extraction from flotation products. Flotation reagents (collectors, frothers, etc.) have various impacts on bioleaching and bacterial activities. In this investigation, the effect of a number of sulfide flotation collectors [potassium amyl-xanthate, potassium isobutyl-xanthate, sodium ethyl-xanthate, potassium isopropyl-xanthate, and Dithiophosphate (Aero3477)], and frothers (pine oil and methyl isobutyl carbinol) with different dosages is studied on Leptospirillum ferrooxidans activities. The results of various measurements indicated that these flotation chemicals can have positive or negative influences on the bacterial activities, based on their chemical compositions and/or concentrations. These results can extensively be used for the selection of flotation reagents when bioleaching is chosen as the metallurgical extraction method after flotation enrichment.

Gravity separation (jigging) and flotation were used to upgrade barite ore from the under developed Mehdi-Abad deposit with general specific gravity (S.G) 3.59 gr/cm3. Jigging experiments on coarse particles did not indicate significant upgrading (S.G 3.94 gr/cm3 and recovery 90%) where barite particles are mainly liberated in fine size fractions (-175µm). Optimized flotation parameters were selected based on results of designed experiments: Na-dodecylsulphate (collector) 750 g/t, sodium silicate (depressant) 2000 g/t, pH 9, size -106+63µm, conditioning time 4 min. Results of flotation tests based on optimized parameters (S.G 4.31 gr/cm3, recovery 94%) showed substantial improvement in comparison with jigging results.

This review addresses the recovery of metals from all the main types of spent batteries (including Li-based, Zn-based, and Ni-based batteries) using bioleaching processes. Traditional processes are based on pyrometallurgical and hydrometallurgical methods and can be costly and, in some cases, cannot effectively recover the metals used in battery manufacture. Biobased hydrometallurgy may circumvent some of these drawbacks. This review presents a classification of batteries based on chemical composition from a recycling point of view. The bacterial and fungal leaching for each type of battery is reviewed. The research outputs are compared in each section, and chemical and biological mechanisms are presented. In addition, the catalytic effect of metals on the bioleaching process is reviewed for each battery. The results indicated that the main bioleaching mechanisms are the reactions of metals with metabolites, acid dissolution, and their combinations with oxidation-reduction reactions. The reactions presented in the literature are assessed and modified thermodynamically. The advantages and disadvantages of batteries bioleaching are discussed, and a future perspective is drawn. Although battery bioleaching has high efficiency and is an environmentally friendly method, with no gas emission and low energy consumption, slow kinetics and low pulp densities are among the major limiting factors hindering bioprocessing development from pilot to commercial scale.

The growing demand for ultrafine powders, coupled with stringent quality requirements, calls for continuous improvements in all aspects of fine particles production. The high energy costs involved in comminution is also an additional motivator. The equipment most commonly used in fine particles processing and the related process parameters is described. Tumbling ball, stirred, vibratory and fluid energy mills are the most commonly used mill types. A number of factors influence the choice of equipment, including the end-use of the product, required product size distribution, sensitivity of the material to heat, and purity requirements. Stirred ball mills are used in ultrafine grinding because of their high unit outputs, while the low amplitude vibro-energy mills are used because of their low specific energy. Fluid energy mills are economic only in some specific applications as in treating heat sensitive materials, materials for plastics and ceramics where purity and delamination are the most important criteria.

The various types of particle shape, morphology, texture, and particle angularity descriptors that are applicable and useful in different grinding methods with respect to various geometric measures existing in image analysis software are presented and reviewed. In addition, some disadvantages of such descriptors are discussed.

In this article the literature on the shape of particles produced by comminution methods and the grinding condition is reviewed and presented. Some agreement and disagreement among workers for the shapes that are produced by comminution are presented. In addition, the important factors affecting the shape of particles in different comminution methods are also described.

Experimental results were obtained with various industrial suspensions with densities of 1100 to 1600 kg/m3 using a 0.15 by 0.1 m four-vane centrifugal slurry pump with an impeller diameter of 0.63 m operating at 650-850 rpm. The non-Newtonian behaviour for a fixated scrubber sludge and a red mud product was characterised in pipeline loops with diameters of 0.075-0.2 m. The lowering of the pump water head and efficiency at the best efficiency flow rate region was at a maximum about 10 and 20%, respectively. With the scrubber sludge, a sharp reduction in head occurred at flow rates below 40% of the best efficiency value, resulting in an unstable head curve. This result is used to demonstrate the risk of unstable operation if a Newtonian correction procedure with a high viscosity is applied giving very large reductions in efficiency and a shift of the best efficiency point to smaller flow rates