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By E. Kalhan, C. Kincal

One of the biggest problems in open pit mining is slope stability. The avoidance of slope stability problems depends on a comprehensive assessment of environmental and operational factors such as geology, climate, and mining activities. In the light of these considerations, slope geometries should be determined in accordance with engineering principles. In this research, the slope stability of rock slopes in a mine opened in a gneiss geological unit has been studied. Production activities were ceased in 2019 due to the slope movements in the eastern part of the quarry. In order to safely continue the production, field works were primarily carried out. To assess slope stability, detailed discontinuity surveys were carried out on bench faces. Subsequently, kinematic and numerical analyses were employed to identify geometries that are expected to maintain stability under the prevailing geological structures and environmental constraints. Engineering geological studies such as scanline measurements in steps and investigation of potential failure mechanisms by kinematic analysis technique were carried out. Small module reactor and Q-slope rock mass classification systems were used to evaluate slope stability. Based on these classification systems potential unstable rock slopes were identified and thematic maps were created using geographic information systems. The most suitable slope geometries are suggested for these slopes. In addition, the improvement methods suggested by the rock mass classification systems were proposed for these slopes.

Sep 1, 2025

By G. Song, S. Yang

"SynopsisThe development of techniques and equipment for single-pass high-seam longwall mining in China is reviewed. Some methods used to obtain the fractured zone height are discussed. The boundary between the caved and fractured zones is generally not clear, but one important difference that distinguishes the two zones is that horizontal compressional forces exist only between blocks of fractured zone. Based on this, a theoretical method is presented to investigate the destabilizing modes of the main roof (by sliding or rotation) and is used to determine if the main roof is in the caved or fractured zone. This method considers the mining height, immediate roof thickness, bulking factor, main roof thickness, main roof strength, main roof periodic weighting interval, and vertical stress in the overlying strata. To verify the method, a representative physical model of Wangzhuang coal mine is developed. The movement of overlying strata and fractured zone height are thus obtained. According to the results, the total collapsed height of the strata reaches about 70 m above the coal floor; the first main roof bending interval is 45 m and periodic bending distance is 10–15 m; the maximum strata subsidence is around 62 mm; and the presence of a three-hinged arch causes the fluctuation of subsidence in the same stratum level. Based on the theoretical and experimental analysis, the middle of the main roof is considered the boundary between caved and fractured zone; the caved and fractured zone heights are about 21 and 49 m respectively.IntroductionThick coal seams (>3.5 m) account for about 44% of the coal rescource/reserves and more than 40% of the total annual production in China (Zhao 2004; Wang 2009). Three mining methods – slice mining, top coal caving, and single-pass high-seam longwall mining – are frequently used in underground thick-seam operations. Compared with slice mining and top coal caving, high-seam single-pass longwall mining significantly simplifies the mining processes, reduces roadway excavation, and improves coal production, productivity, and recovery. The favourable economics, high production, and technical simplicity make high-seam single-pass longwall mining one of the most popular underground mining methods for thick coal seams in China."

Jan 1, 2015

By M J. Daniel

The diamond industry is no newcomer to High Pressure Grinding Rolls (HPGR) as it has used the technology for more than 20 years, predominantly in secondary crushing and recrushing roles. In fact it could be argued that the diamond industry has led the way for the wider minerals industry to consider its application. In existing conventional secondary cone crushing applications, large valuable diamonds are" won" through meticulously managing the recovery process within defined particle size ranges. Conventional crushers operate with relatively large closed side settings, but have the potential to damage diamonds by making direct contact with the sides of the crusher. Cone crushers also result in steep product size distributions that run a high risk of losing many of the smaller, unliberated but more abundant diamonds from the rock. This current comminution paradigm of particle size reduction management results in recrushing processing applications or plants where HPGRs are often used.

Jan 1, 2010

By M. S. Shishvan, S. Klerkx, J. Sattarvand

The inaccurately drilled blastholes from the planned locations cause changes in the spatial distribution of explosive energy; some areas of the blast may receive a surplus of explosive energy, while others see a reduction. This results in less uniform fragmentation, reduces the efficiency of mining operations and increases costs. Additionally, it can lead to slope stability issues, flyrock, and uneven benches. To mitigate these problems, this study attempts to reduce differences in the explosive energy distribution (EED) through an optimization approach that adjusts the height of explosive columns in blastholes. Two optimization algorithms, the Genetic Algorithm (GA) and Tabu Search (TS), are tested. The latter is preferred for its local search neighbourhood strategy that gives superior computation times. Applications on different blast patterns result in improvements of 0.53–1.54%, or 2.14–3.94% when only the affected blocks are considered.

Sep 1, 2021

By E. Van Der Lingen

This paper provides a review on coloured gold, platinum, andpalladium intermetallic compounds, and discusses the models thatwere developed to obtain these materials. These compounds have acrystal structure of high symmetry, such as the CaF2or CsClstructures, ensuring distinct electron band structures. Variousexamples of coloured gold, platinum, and palladium intermetalliccompounds are provided. More in-depth discussion is provided on thepurple gold (AuAl2) and yellow platinum-aluminium (PtAl2)compounds with CaF2structure, as well as the purplish-pinkpalladium-indium (PdIn) compound with CsCl structure. Precious metal intermetallic compounds are used in jewellery andprovide a new dimension to design. Some of these compounds havealso found use as barrier coatings on turbine blades for jet engines,and more recently, research has been conducted into their potentialuse as catalysts, electro-catalysts, sensors, capacitors, and fordecorative coatings.

Jan 1, 2014

By G. Akdogan, S. M. Bradshaw, M. I. Isaacs, P. Van Wyk

In the mineral processing industry, Ni-Cu-Fe-S converter matte is leached in order to remove base metals from a concentrate containing platinum group metals (PGMs). This paper investigates the atmospheric leaching process, in order to develop a better understanding of the leaching behaviour of the base metals; in particular Cu, Fe, Ni, and the PGMs in particular Ru and Ir with key process variables, acid concentration, copper concentration under oxidative leaching conditions. Higher initial acid concentration resulted in a higher copper, iron and nickel extractions, as well as higher leaching rates together with faster Cu, Ru, Ir precipitation occurring. On the other hand, a higher initial copper concentration resulted in more nickel but less iron being extracted. Keywords: PGM, converter matte, leaching, precipitation

Jan 1, 2020

By T. Käyhköa, J. Liipoa, S. Khizanishvilic, M. Sinche-Gonzalezb

The use of geometallurgical modelling is becoming more common in concentrator plant design and during the operational phase. Predictive modelling aims to define optimised process parameters for the concentrator plant to accommodate variability within the ore feed. The main objective of this study is to show how the metallurgical response of different types of ore blends can be simulated using kinetic models derived from experimental flotation tests with different geometallurgical end-member ore types and their blends. For these validation tests, four different end-member ore types containing different ratios of chalcopyrite, chalcocite and oxidised copper minerals from Rich Metal Group’s Madneuli copper-gold mine, Georgia, were tested. Kinetic flotation tests, including both rougher and cleaner flotation tests, were carried out. The simulations were performed using HSC Chemistry software based on mineral compositions of the ores and kinetic models using rectangular distribution equations and flowsheet model. Simulated and experimental results of copper grade, copper recovery and concentrate mass pull correlated well with R2 values of >0.95. Based on these results, the metallurgical response of different ore blends can be simulated based on the flotation kinetics of end-member ore types. The use of this kind of simulation will create savings during the test work phase and increase the flexibility and predictability in the processing stage. Keywords: Ore body characterisation, geometallurgy, process mineralogy

Jan 1, 2020

By L. Scott, M. A. Goncalves

Effective communication is a sought-after non-technical skill in the health, safety, and environmental (HSE) function and is fundamental in achieving an organization’s safety objectives. While different channels are used to communicate HSE matters, many organizations employ posters, videos, and/ or signs containing images to convey information. Communication through signage and graphical hazard symbols has been regulated in standards, but vast sections of HSE communication are bespoke communications and exist outside the sphere of standards. Effective HSE communication through images requires an understanding of the organizational culture in which the images will be used, as well as an understanding of the semiotics of the images themselves. Creative interpretation within HSE communication can create situations where the message that was received is not the message that was intended, leading to confusion and misinterpretation. This paper is aimed at elucidating the semiotics of South African HSE visual content. It was found that the indexical mode of images was most preferred in visual communication, and text-only designs the least preferred. Senders and receivers of messages differ in their opinions on the complexity of HSE communication.

Feb 2, 2021

By R. G. Coyle

"In an earlier paper the author explored the consequences of price-stabilizing effects, on an industry-wide basis, of various production strategies. These ideas have now been applied to an illustrative case of an individual mine. It is shown that the turning of production and financial policies can affect financial performance over a five-year period by as much as 22 per cent.No generality is claimed for the results and they would differ from mine to mine. It is, however, asserted that the results show that the proper turning of production, reserves and financial policies are more critical determinants of mine performance than has been realised. It is also asserted that the methods of dynamic analysis are the most appropriate means for studying this policy-design problem."

Jan 1, 2014

By E. J. Magri

Consideration is given to the problem of the estimation, from limited data, of the likely grade and tonnage for a new mining property that is to be exploited by the selective mining of two metals that have substantial contributions to make to the total revenue. In particular, the case of a new gold and uranium mine in South Africa is analysed as follows. (I) The applicability of the underlying lognormal bivariate model for different support (i.e. ore unit) sizes is examined. (2) The necessary parameters for the bivariate lognormal models for different block sizes are estimated from abundant chipsampling data from a section of the Hartebeestfontein Gold Mine using alternative approaches, and the results are compared. (3) A method is given for obtaining the necessary parameters for a tonnage-grade relationship relative to a joint pay limit from the very limited information likely to be available at the end of the exploration stage of a gold mine, and the results are compared with those obtained from the large volume of data available from a minedout area.

Jan 1, 1982

By R. Lechuti-Tlhalerwa

"Geometallurgy aims to improve mining project value by predicting the impact that ore and waste characteristics will have on mining and metallurgical processes. This requires integration of rich spatial models of orebody characteristics with validated process response models. These models have, until recently, been constrained by the spatial coverage and representativity of relevant data and the ability to validate predictions made.The revolution in the diversity and volume of data and computational power that is now becoming available for integrated geoscientific modelling of orebodies, and stochastic simulation of mining and mineral processes is accelerating. By embracing emergent integrated data analysis and simulation techniques, geoscientists and engineers can lead a transformation in the way the mining value chain, from orebody to recovery, can be conceived, evaluated, and operated by using the geometallurgical paradigm.This paper describes a methodology that is applied to an existing diamond operation. Analysis of spatial and process data is used to build an integrated geometallurgical value chain model (IGVCM). This IGVCM is used to generate geometallurgical options and evaluate their potential outcomes. The model facilitates the use of flexible, highly configurable, and potentially automated intelligent approaches to evaluate mining and mineral process configuration, and results in more robust design outcomes. The approach described here, and its successful implementation has potential to deliver step-changes in value. IntroductionGeometallurgy aims to identify treatability risks – and opportunities – that arise from the interaction of orebody characteristics with mining and treatment. Improved understanding of the rock/process relationships allows project planners and production teams to predict performance, identify potential shortfalls, and thus enable the proactive creation and evaluation of strategies to mitigate these risks. These advanced insights also create opportunities for continually improving operational performance through dynamically adapting and improving the process response to the changing properties of the ore (Figure 1)."

Apr 1, 2019

By E. Van Der Lingen

Within the context of the overall gold market industrial demand plays an important role. Industrial demand for gold was 430 tonnes in 2008, approximately 12% of total end-user consumption. The dominant consuming industry in this market for gold remains the electronics sector, consuming an estimated 300 tonnes, primarily through the use of gold bonding wire for computer chips and plated contacts and connectors. Substantial demand also derives from dental applications, with other smaller industrial markets and decorative uses of the metal (non-jewellery) constituting the balance. In each market gold faces tough competition from alternative lower cost materials, such as silver and copper (electronics) and ceramics (dental). As well as the obvious benefits to the gold market resulting from this constant physical demand, there are an umber of additional positive factors concerning the use of gold in industrial applications: ?Price inelasticity: demand for gold from the major consuming industries has so far proven to be relatively robust in the face of significant increases in gold price. ??Stickiness?: the gold consumed by industrial uses tends not to return easily to the market (i.e. the demand is ?sticky?) because it is highly dispersed. ?Image: the beneficial environmental and medical applications of gold (e.g. gold used in the treatment of prostate cancer and in purification of contaminated water) are helpful to the positive image of gold. ?Added-value: new industrial uses for gold can create substantial added value in the supply chain, particularly in gold producing countries.

Jan 1, 2009

Discussion of the previous paper E. N. H. MOLLOY The first 22-foot-diameter Aerofall mill was installed at Mangula in 1957. This was fitted with cast-iron trunnion'! located to the mill shell with 2-inch-diameter mild-steel bolts. O.F .S. Branch Minutes of the General Meeting held at the Welkom Club on Wednesday, 2nd June, 1976, at 4.00 p.m. Mr G. J. C. Young (Chairman of the O.F.S. Branch) was in the Chair. Also present were:

Jan 9, 1976

By S. Kahraman

The prediction of rock properties from indirect testing methods is important, particularly for preliminary investigations since indirect tests are easier and cheaper than the direct tests. In this study, we investigate the predictability of the uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) of rocks from the indentation hardness index (IHI) obtained using point load apparatus. Forty-six different rock types, 14 of which were igneous, 15 were metamorphic, and 17 were sedimentary were tested in the laboratory. The UCS and BTS values were correlated with the corresponding IHI values and the results were statistically analysed. The influence of rock classes on the relationships was also investigated. A strong correlation between UCS and IHI was found for all data. The correlation between BTS and IHI is not as strong as the correlation between UCS and IHI. However, it is in the acceptable limits. When the regression analyses were repeated for igneous, metamorphic, and sedimentary rocks, the correlation coefficients were generally increased. The results show the UCS and BTS can be estimated from IHI. In addition, the effect of rock classes on the relationships between IHI and both UCS and BTS is important.

Jan 1, 2012

By G. Pienaar

The South African Institute of Mining and Metallurgy held a Colloquium on High-strength Low-alloy Steels on 27th October, 1983, at the Vaal Triangle Technikon, Vanderbijlpark. The Colloquium was attended by some 170 delegates.

Jan 1, 1984

By M. R. Khalesi, Y. Kianinia, A. Seyedhakimi, F. Soltani

"The feed ore to Agh-Darreh gold processing plant (Takab City, Iran) contains 2 ppm Au, 7 ppm Ag, and 120 ppm Hg. After cyanide leaching of the feed at pH 10.4, 80% of the total mercury (in the form of cinnabar and metacinnabar) goes to the tailings dam. In this research, separation of mercury from the tailings by flotation was investigated. The effects of collector type and dosage, pH, and the number of cleaner stages were studied. The results showed that after two stages of cleaning a 40–62% recovery of Hg at a grade of 14.3% Hg is attainable. Recycle water from a test in which 50 g/t amyl xanthate and 30 g/t pine oil was used in the flotation stage showed no adverse effect on the leaching and adsorption of gold onto activated carbon.IntroductionMercury, most commonly found in the nature as the mineral cinnabar (HgS), is a hazardous substance because of its mobility and toxicity (Kyle et al., 2012). Roasting is the wellestablished treatment method for mercury ores, in which the sulphur is burned and volatilized and mercury recovered subsequently by cooling and condensation. However, for low-grade ores, flotation is mainly applied for primary concentration due to its comparatively low costs, low environmental hazards, and flexibility regarding feed variations (Bulatovic, 2007). Particularly, cinnabar can be easily recovered by flotation using pine oil and a collector such as xanthate (Bulatovic, 2007; Crozier, 1991). Floatability of cinnabar is reduced due to surface oxidation when it is exposed to the atmosphere after crushing. This problem can be eliminated by adding copper sulphate and lead nitrate or acetate. The best pH for cinnabar flotation is in the range of 6.5 to 8.5 according to Erspamer and Wells, (1954), who reported that cinnabar and stibnite can be floated with long-chain xanthate collectors and an alcohol frother, with cumulative recoveries of 97.8% and 94.7%, respectively. Lead acetate was used as an activator."

Jan 1, 2017

By J. Gholamnejad

Determination of the optimum production schedules over the life of a mine is a critical mechanism in open pit mine planning procedures. Long-term production scheduling is used to maximize the net present value of the project under technical, financial, and environmental constraints. Mathematical programming models are well suited for optimizing long-term production schedules of open pit mines. There are two approaches to solving long-term production problems: deterministic- and uncertainty- based approaches. Deterministic-based models are unable to deal with grade and geological uncertainties, which are two important sources of risk in mining industries. This may lead to discrepancies between actual production obtained by these algorithms and planning expectations. In this paper, a new binary integer programming model was developed for long-term production scheduling that incorporates geological uncertainty within the orebody. Then, traditional and uncertainty-based models are applied to an iron ore deposit. Results showed that the uncertainty-based approach yields more practical schedules than traditional approaches in terms of production targets.

Jan 1, 2012

By A. Pareek, V. S. Masampally, V. Runkana

Mineral processing plants, in general, consist of comminution and separation circuits. Rougher flotation is considered as the heart of the separation circuit with concentrate grade and mineral recovery being the key productivity and quality parameters that affect the downstream operations and profitability. Online prediction of these parameters can help improve process performance in real-time. Past efforts to predict flotation cell performance have focused on building physics-based or machinelearning (ML) based models. Although physics-based models are popular in process design applications, ML models are more appropriate for online monitoring, control and optimisation due to their lower computational requirements. Deep learning (DL) is gaining prominence nowadays for application in industrial operations where a large amount of data is available. We have developed a DL model based on long short-term memory (LSTM) neural networks to forecast the two key performance indicators (KPIs), namely, mineral recovery and concentrate grade in a mineral processing plant. Rougher feed characteristics such as mineral grade and particle size distribution, upstream measurable disturbances such as throughput of the comminution circuit and pulp density, and control variables such as aeration rate, pH, and collector addition rate are considered as explanatory variables to train the model. The model was tested with data from an industrial mineral processing plant. For real-time dynamic predictions, the trained model appropriately accounts for mismatch in measurement frequency of real-time process data and off-line laboratory analysis data. Such a time series model can be used as a state observer in model predictive control techniques for optimal control of unit operations in a mineral processing plant. Keywords: Mineral processing, flotation, time-series, dynamic modelling, deep learning

Jan 1, 2020

By I. Soto, E. Córdova, A. Anani

The new caving megaprojects that are planned to go into production in the next decade have scheduled horizontal developments at very high rates, which are difficult to achieve. Research has been conducted that seeks to model the construction times for underground developments to determine the feasibility of achieving the planned rates. However, these previous attempts do not consider all the operational aspects that make up the mine development cycle. Here, we present a discrete event simulation (DES) model that individualizes each unit operation of the development cycle to determine the construction rates that new projects will be able to attain. The developed model was applied to the New Mine Level (NML) of the El Teniente Division (DET). The results indicate that it would be impractical to achieve the advance rates scheduled in the original plans if the unit operations of the mine continue to be executed using the status quo. The metres developed after six years in the sections analysed can be significantly improved by changing the maintenance strategy for the equipment (457 metres increase), orepass availability (194 metres increase), and the initial planning sequence (1 598 metres increase). It is recommended that the mine implements a flexible maintenance strategy, defines a strategy to ensure and increase orepass availability to contractors, and makes use of current simulation tools for a more robust development sequence planning.

Oct 1, 2022

Metso Minerals Process Technology Asia-Pacific (MMPT-AP) has been working with many mining companies worldwide performing `Mine to Mill' or Process Integration and Optimisation (PIO) studies. MMPT-AP has developed a proven methodology to improve the efficiency of the mine-mill interface and gain maximum benefit. The PIO methodology involves rock characterisation, mathematical modelling and simulation to generate a list of operational and control changes for both the mine and concentrator. Following the methodology, the list of recommendations is developed relatively easily; the more challenging part depends on the company. Success of a PIO project relies on the ability of an organisation to implement change - both operationally and culturally: the human element. When a PIO project is started, there is initial interest and commitment from the company. But how can this be maintained? How does an operation know if the benefit continues? MMPT AP is now developing long-term relationships with clients to ensure that the increased production and improved efficiency continues. Direct and indirect measurements are used to determine the key factors involved and to understand the cause/effect relationships. Simulation tools also can be used to compare current with recommended practices - so when material properties vary over time, the benefits can still be quantified. PIO is about empowerment: by measuring and understanding what parameters affect concentrator performance, the site personnel now have the knowledge to make a difference. Rather than simply reporting variable or poor concentrator performance, operations can predict when production will be affected and put controls in place to prevent it from happening. This requires support and commitment from the company or `buy in'. Ensuring this buy in continues is the challenge facing every company involved in PIO work - but the benefits are well worth it. This paper will review MMPT-AP's experiences in implementing PIO projects in the long term: from both the consulting and operational viewpoints. MMPT-AP's involvement with a number of companies will be discussed as examples of what works and what does not.

Jan 1, 2007