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On the Role of Dixanthogen in Froth Flotation

Sep 13, 2010

Preparation of MgO Nano-Particles with Magnesite

Sep 13, 2010

The Role of Mineral Processing in the Development of Cement with Low Carbon Emissions

Sep 13, 2010

TowerMill - Advantages in Wet Grinding Applications The TowerMill, which has now been in existence for no less than 50 years, is one alternative to the horizontal ball mill and offers several advantages. The TowerMill is widely used in (coal-fired) electric power plants for the grinding of raw material for the FGD (Flue Gas Desulphurisation) process involving very high throughputs, very fine product sizes and high availability. Some companies in the mining industry also looked at the use of such optimised grinding machines several years ago and found that many of the advantages offered in other industries are transferable to new applications. Much development work has been undertaken to improve the TowerMill for new applications and, as part of that work, tests have also been conducted to make direct comparisons of their performance with that of ball mills. Grinding tests were performed using the same raw materials and comparable machine sizes. Some of the results are discussed in this paper, along with a comparison of the advantages and disadvantages. The conclusion provides an outlook for some worthwhile future applications. The test results, which are described and analysed, show that the TowerMill offers significant advantages in relation to operating costs and operational safety. An example based on the wet grinding of limestone is presented.

Sep 13, 2010

Performance of Dry Separation Processes in Cenospheres Recovery from Coal Fly Ash

Sep 13, 2010

Validation and Simulation of Optimised Compressive Crushing Ores and aggregates are used in countless applications all around in the society. The frequent and escalating usage of these natural resources requires efforts aimed at not only making do with what is available, but also undertaking actions to improve the production yield and the processes involved. This strive to improve the performance and efficiency of existing crushers and crushing processes has brought about research concerning optimisation of crushing plants as well as theoretical optimisation of crushing. Previous work shows that different applications and different materials require different compressive crushing in order to accomplish a theoretically optimal size distribution. These optimisation results, obtained by genetic evolutionary algorithms and evaluated with so called fitness functions, convey the theoretically optimal number of compressions and their corresponding compression ratios. Presented in this paper are thus some laboratory crushing tests, which are conducted in order to validate a set of previously optimised crushing sequences. More specifically, interparticle crushing sequences are carried out in a Piston-die testing equipment, where samples are sieved between each compression. The subsequent analysis of these results shows good correlation with model predictions, which combined with a comparative study between presented optimisation results and measured data from a real crusher indicate a significant potential for improvement. However, before redesigning crushers according to what is theoretically optimal, the resulting impact as well as the effects on the outcome of a crushing plant must be examined. Crushing plant simulations using the software PlantDesigner« are consequently performed. Models of existing crushers are altered, resulting in changed particle size distributions from some of the crushers in a crushing plant. Thence, it is concluded that significant gains can be made in terms of capacity, process yield and energy consumption.

Sep 13, 2010

Flotation Circuit Optimisation - Towards More Sustainable Practice

Sep 13, 2010

Reason Analysis of Impurity Containing and Technology Discussion of Quality Improvement for Low-Quality Iron Concentrate

Sep 13, 2010

The Effect of Bulk Iron Concentration on the Copper Activation of Sphalerite at pH 9

Sep 13, 2010

Treatment of Gold-Bearing Oxide High-Clayish Ores The analysis of modern state of treatment technologies of gold-bearing oxide high-clayish ores showed that the main method applied both in Russia and abroad is sorption leaching and heap leaching with preliminary granulating. The use of any of these processes depends on many factors including average gold grade, site and area of a deposit, clay content and etc. The two processes are often used at the same deposit. In this case, rich ores are treated according to a plant technology, poor ores and ores with cut-off grade are treated with heap leaching. Both technologies possess their own advantages and disadvantages. A plant technology is characterised by high recovery with higher capital and operating costs at the same time. Lower recovery during heap leaching can be attributed to an unstable quality of ore granulating due to both technological and weather conditions. In case of poor high-clayish ores, the use of a combined ore treatment is possible and profitable. It includes the ore disintegration and a clayish fraction treatment by using a heap leaching. In this case, capital and operating costs reduce in comparison with a plant technology and the recovery increases in comparison with heap leaching. Sometimes it reaches a plant recovery. These ores possess special features. As a rule, gold is associated with ore fraction, so it liberates readily from the association with ore ore-forming minerals even with relatively coarse grinding explain their high solution velocity in a hydrometallurgical cycle. Clayish ores are characterised by high sorption activity to gold cyanide complexes as well as extremely low velocity of filtration and thickening of slimic pulps at the same time. The paper describes the options of oxidised high-clayish ores treatment, such as, a plant technology (PIP and CIP process), heap leaching and a combined technology (disintegration, heap leaching of a crystalline fraction and sorption cyanidation). The obtained results were used when selecting a treatment technology and during construction of a plant for oxidised high-clayish ores treatment.

Sep 13, 2010

Crushing Plant Process Optimisation Design of processes in order to find the most efficient solution to a specific task is a difficult problem. Often the number of solutions are large and the optimal solution is therefore difficult to identify. Crushing plant process design is no exception from this statement. In order to find the best solution issues like equipment selection and process configuration must be mastered. The solution must both be technically feasible and preferably have a low operating cost. Since crushing plant design is a complex task with a large solution space it is basically impossible to master without a specialised tool. For a long time simulation softwares have been used to assist in the design process. These tools only give answers for how a user defined plant will operate. There are no tools with capabilities to consider different design options in order to determine what the most efficient solution looks like. In this paper a method for crushing plant design optimisation is presented. The novel method utilises a combined optimisation routine and expert system in order to find the most cost efficient solution to a given process task. The user will only need to define the feed material properties, the process capacity, and the end product requirements. The developed system will find the solution lowest production cost per ton.

Sep 13, 2010

The Study of Jamesonite Flotation Behaviour

Sep 13, 2010

Approximation of Surface Area of Fines in Blast Induced Fragmentation The surface area of fragmentation, especially in the finer size fractions, is a useful property to characterise the mechanisms of rock breakage. In the past, researchers have made assumptions with regard to the shape of fragments in order to estimate surface area, such as that all fragments are the same shape or all fragments are spheres. Often these assumptions were developed with inappropriate measures and returned considerable variability and error for the calculation of surface area. This paper reports a model to estimate fragmentation surface area from sieve sized raw data and a density measurement, with experimental validation down to a size fraction of -45 + 38 ?m in a range of rock types. After characterisation of particle shape, a range of fragment shapes was found to be in each size fraction. Nevertheless, in the ?2 sieve series the average fragment mass, volume and the size fraction standard deviations could be predicted reasonably accurately. Ellipsoid geometry was used to describe particle shape. Using these parameters and the number of fragments (also predicted) in each sieve size the individual surface area of each fragment was simulated.

Sep 13, 2010

Using DEM to Model Industrial Banana Screens

Sep 13, 2010

Cyclonic Separation Effect of Metallic Ores in Cyclonic-Static Micro-Bubble Flotation Column

Sep 13, 2010

Innovative and Resource-Preserving Washing Processes for Primary and Secondary Raw Materials

Sep 13, 2010

Igneous phosphate deposits located in tropical and subtropical regions of the world are characterised by low P2O5 grades, very diversified mineralogy and intensive lateral plus vertical variations in chemical composition, mineralogical assembly, rock texture, grain size, slimes content and morphology plus surface coating of apatite particles. Those variations characterise ore types with distinct behaviour in mineral processing plants. This work reviews the main challenges to concentrate those ores, addressing developed solutions. Apatite concentration requires long chain anionic collectors to conduct reverse flotation of barite (alkyl sulfate) before direct flotation of apatite (sarcosinate, sulfosuccinate and oleate) at basic medium. The long chain collectors decrease the surface tension of the flotation solution (?LV) and a particular value of 51 mN/m was found to promote the most selective separation between apatite/gangue at a particular plant. Effective control of the magnitude of ?LV in industrial plants has not been realistic because there is a lack of reliable instruments to carry out in-situ measurements. Regarding gangue depression by starch, a review is made on possible mechanisms that promote its remarkable ability to depress some minerals (Fe-oxides, ortho plus meta silicates and calcite) vis-a-vis others (quartz, apatite and layered silicates). Flotation recovery (R) of fine (20<R<30 per cent) and coarse (30<R<60 per cent) apatite particles is considerably lower than the recovery of the intermediate ones (R>70 per cent) and inadequate hydrodynamic conditions within flotation cells are the main reasons for that behavior. Once the best hydrodynamic conditions to float coarse particles are not the same to float the fine ones, flotation of coarse and fine particles is commonly conducted at separated circuits in industrial scale. Entrainment of very fine gangue particles is an important source of contamination of apatite concentrates, mainly when weathered ores are treated. In most cases, adjustments in flotation equipment (columns or mechanical cells) promote considerable improvement in the quality of final concentrates.

Sep 13, 2010

Recovery of Pentlandite and Chalcopyrite from Tailings by Bi-Cyclone Powerful Flotation Column

Sep 13, 2010

The Physical Basis of Non-Random Breakage in an Iron-Oxide Ore Hosted Copper Gold Ore

Sep 13, 2010

Adsorption of Alkylammoniums in the Interlayer of Montmorillonite and its Effect on the Viscosity of Organo-Montmorillonite Gels

Sep 13, 2010