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By M. Kilfoil

Many minerals processing operations result in crushed rock being mixed with a liquid. Sometimes, the rock particles have to be dried before the next process begins and there may be a considerable distance between the equipment carrying out these processes. Bateman Engineered Technologies (BET) developed, patented and commercialized a method of simultaneous pneumatic conveying and drying. A joint project to assist with optimizing the process is under-way. Part of it is a numerical simulation of the process. The simulation is done using a dedicated program written in MATLAB, (commercial software which is widely used in engineering). It accounts for heat and mass transfer as well as particle transport. The main part of the program consists of a loop containing a series of equations which are evaluated sequentially. During any particular iteration, the properties are changed one at a time. Since the properties are changing relatively slowly, this method gives good results. The outputs of the simulation are consistent with the operational experience of BET’s engineers. The output is very comprehensive and all numerical. Since the program is currently being used for research purposes, flexibility is very important. Thus the output is converted into a spreadsheet file. Variations in the output quantities are displayed graphically using MS Excel. Some simulation could have been done using computational fluid dynamics (CFD) software. The advantages and disadvantages (technical, financial and skills requirements) of the two approaches for this particular type of simulation are compared briefly. Keywords: Pneumatic conveying, Heat and mass transfer, Computer model

Jan 1, 2003

A banquet, attended by 467 members and visitors, was held at the Wanderers Club, Johannesburg, at 8 p.m. on Friday, 21st March, 1969, to celebrate the 75th Anniversary of the founding of the Institute. Introduction of Dr Carel de Wet R. C. J. Goode (President) Dames en here: Ons het 'n aantal vooraanstaande gaste in ons midde vanaand en mnr Maxwell sal u later meer van hulle vertel. Dit is my aangename plig om u voor te stel aan sy Edele, die Minister van Mynwese, van Beplanning, en van Gesondheid, Dr de Wet en sy gade, mev de Wet. Sy Edele Dr de Wet het geen bekendstelling nodig nie-alhoewel hy ons minister vir slegs die afgelope twee jaar is, het hy reeds talle funksies van ons Mynbedryf bygewoon en het baie vriende gemaak onder ons. Hy het homself baie bemind onder ons gemaak toe hy Wes-Driefontein onlangs besoek het om hulle ondersteuning en aanmoediging aan te bied in hulle uur van nood. The Honourable Dr de Wet was born in the Free State. He is a grandson of that very famous general Christiaan de Wet, who caused so much pain to the British forces and for so many months so successfully eluded them in the Transvaal and Orange Free State. He was educated at both the Pretoria and Witwatersrand Universities. He first practised medicine at Boksburg and then moved to Vanderbijlpark, so you see he has an early association with gold mining on the Witwatersrand, and in moving to the Vereeniging-Vanderbijlpark district he became closely involved in our coal mining and metallurgical industries. South Africa's first steel was poured from a l0-ton open hearth furnace belonging to the Union Steel Corporation in Vereeniging in 1913. Dr de Wet has been mayor of Vanderbijlpark and for several years has been their member of parliament. More recently, the Honourable Dr de Wet has filled with great honour that most important office of Ambassador for the Republic of South Africa in London. At present he wears two hats, in that he is Minister of Planning and of Health, but more important is his cloak, that of Minister of Mines, which I trust offers him the greatest comfort. To fulfill these three arduous tasks must demand of him a terrific devotion to duty, and in doing this he carries on that loyal tradition of service to his fatherland so evident in his grandfather. Dames en here, dit is vir my 'n groot genoeë om Sy Edele Dr de Wette vra om 'n heildronk in te stel op die Instituut vir Mynwese en Metallurgie. Toast to the Institute of Mining and Metallurgy Dr the Honourable C. de Wet (Minister of Mines): Mr President, ladies and gentlemen, Mr President you have introduced me gracefully to this distinguished company and I am appreciative of your remarks. I am fully conscious of the responsibilities that devolve upon me as Minister of Mines in a country where mining makes so vital a contribution to economic progress and development and has, in fact, laid much of the foundation on which our present proud edifice is built. The achievements of the mining and metallurgical industry in its diversified activities arouse feelings equivalent to paternal pride, but let me speedily add that in considering any family relationship that may exist, the Minister of Mines should not be regarded in the role either of a fairy godmother or an indulgent father.

By T. M. Chagwedera, A. E. Lewis, J. Chivavava

Eutectic freeze crystallisation is a novel separation technique that can be applied to treat brine solutions such as reverse osmosis retentates, which are often a mixture of different inorganic salts. The treatment of calcium sulphate-rich brine solutions through eutectic freeze crystallisation has resulted in gypsum scale formation on the walls of the crystallisers and ancillary equipment. In order to prevent gypsum scaling on equipment surfaces, it is essential to understand the mechanism of gypsum scaling on cold surfaces. This paper focused on the interaction between gypsum crystallisation in the bulk solution and scaling on the crystalliser walls in the presence of gypsum seeds. A cooled, U-shaped stainless-steel tube suspended in the saturated solution was employed as the scaling surface. Preliminary results showed that the scale layer was predominantly composed of needle-type and hexagonal prismatic crystals. The rate of scale deposition was highest during the first 24 hours, thereafter it decreased. A thin scale layer was observed to have coated the tube within the first hour of the experiment. Seeding, using reagent grade gypsum crystals, was effective in reducing scale layer formation through providing a surface for growth. The highest scale reduction, 81%, was realised at a seed loading of 0.50 g/L. At a high seed loading of 4.01 g/L, the seed material adhered to the tube. Keywords: Gypsum, eutectic freeze crystallization, seeding, scaling, cooling crystallisation

Jan 1, 2020

By V. Oberholzer

The presence of fines (particles smaller than 6 mm in diameter) causes hydrodynamic problems in gasifiers and therefore it is of great importance to minimize the amount of fine coal in the feed. This serves as motivation for understanding coal?s breakage mechanisms, which could lead to the ability to predict the generation of fines. The aim of this project was to simulate the pulsating effect of the conveyor belt in order to investigate factors influencing the breakage. Results indicated that an increased initial particle size had an increasing effect in the amount of fines generated. Weathering had an insignificant effect on the breakage of coal. To conclude, a breakage model was developed to describe the rate of breakage out of the top size when a combination of two breakage modes is present.

Jan 1, 2009

By E. M. W. Skinner

Various models of near-surface kimberlite pipe emplacement have been proposed over the years. These include a top-down, phreatomagmatic model, a bottom-up, embryonic pipe model and three top-down explosive dyke models. AU of these models consider kimberlites as essentially the same rock type. However, different kimberlites have different pipe shapes and contain different rock types with very specific mineral assemblages and textures and therefore are likely to have been emplaced by different processes. Some authors have considered local geological differences as the principal reason for the contrasting geology but others argue that, while geological differences might contribute locally the petrographic peculiarities of particular kimberlites may be due mainly to inherent compositional differences specifically in the ratios of juvenile CO2 and H2O.

Jan 1, 2010

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 A. Chagnes

This paper presents a modelling tool that can be used to predict the behaviour of solvent extraction processes. In particular, this model allows calculating metal extraction efficiency as a function of pH, solvent flowrate, stripping flowrate and aqueous feed flowrate in the mixers-settlers. This model is applied to the recovery of cobalt from acidic chloride media by using CYANEX® 272 as extractant diluted in kerosene. Keywords: Cobalt, mixer-settler, modelling, solvent extraction

Jan 1, 2020

By A. Della Rocca, P. Jonker, B. Henning

Successful prediction of the collection efficiency of cyclone separators is a necessary step in cyclone design and verification. Aside from standard empirical relations, CFD modelling is widely adopted to supplement the design of cyclone units in relation to the desired separation performance. Nevertheless, effective adoption of numerical modelling is sometimes prevented by large modelling errors, especially for small size particles which are more subject to turbulence effects than larger particle classes. In the past, this motivated the adoption of more refined turbulence modelling approaches, such as large-eddy simulations. These approaches provide greater insight into time dependent behaviour, while leading to larger computational cost with respect to more standard approaches. In this paper, an effective Eulerian-Lagrangian Reynolds-averaged Navier-Stokes (RANS) approach is investigated, which is able to predict the complete separation efficiency curve with satisfactory accuracy, without requiring prohibitively long computational times. An assessment of the proposed approach is carried out against experimental data from large laboratory scale cyclones, in the form of mean and fluctuating velocity profiles from LDA measurements (Hoekstra, 2000), as well as with respect to the experimental separation curve (Zhao, 2005). The final application to a full-scale industrial cyclone unit is then carried out with the aim of tuning the cyclone design to the separation efficiency curve as required by downstream processes. Keywords: Cyclones, separation, CFD, RANS, RSM, Lagrangian

Jan 1, 2020

By Y. Wang

Arsenic-bearing acidic effluent from hydrometallurgical processes contains many harmful metal ions and must be appropriately treated before discharge. In the present study, arsenic, copper, zinc, aluminum, and magnesium were co-precipitated by means of the Fenton reaction. The precipitates obtained under different conditions were investigated to determine their stability. The results indicate that pH value and hydrogen peroxide (H2O2) dosage have significant effects on the removal of various elements. Arsenic, copper, zinc, and aluminum (but not magnesium) can be removed at pH 5–6 and anH2O2/As mole ratio of 2 at ambient temperature. The precipitates were mainly amorphous and granular with particle size in the micrometre range. The arsenic concentration in leachate from the toxicity characteristic leaching test was 3.6 mg/L, which proves that the precipitates are effective in fixing arsenic.

Aug 3, 2023

By U. Atici, R. Comakli

"Understanding rock properties is of vital importance in mining and civil engineering. Rock properties are generally determined through laboratory tests, which require a large number of uniformly shaped samples and technicians who use indirect methods to determine rock properties. The texture coefficient (TC), which represents various textural parameters including the size, shape, orientation, and relative proportions of grains and the matrix, is an efficient means for indirectly evaluating the mechanical behaviour of rocks. In this study, 12 different rocks (ten granites, one diorite, and one gabbro) were collected and their engineering properties. including specific gravity, porosity, P- and S-wave velocities, Schmidt rebound hardness, uniaxial compressive strength, and elasticity modulus, were investigated. Relationships between TC and these measured properties were assessed. Statistically significant (at the 95% confidence level) correlations were found between the TC and compressive strength, elasticity modulus, sound velocity (both compression and shear waves for dry and saturated samples), but no significant correlation was found with Schmidt rebound hardness. The results suggest that it is possible to use the relationships between TC and the mechanical properties of rocks in rock classification. IntroductionIn every aspect of rock engineering, knowing rock properties is essential for determining and predicting the behaviour of rocks and rock masses. Mechanical properties of rocks are important parameters in mining, geology, and engineering, and they are affected by textural characteristics such as grain size, grain shape, cement type, degree of cementation, mineral content, and the ratio of the grain area to the matrix area. The effects of textural properties on the physical and mechanical properties of rocks have been investigated for a long time, and previous studies revealed close relationships between single parameters related to rock texture and mechanical properties of rocks (Akesson et al. 2001; Gunsallus and Kulhawy 1984; Merriam, Rieke, and Kim, 1970: Onodera and Kumara 1980; Prikryl 2006; Ulusay, Tureli, and Bider, 1994; Tugrul and Zarif 1998). Rock properties are usually determined using mechanical tests, which require uniformly shaped and relatively large samples. However, it is not always possible to obtain such samples. Furthermore, rocks with similar textural and structural properties may exhibit different mechanical behaviour. Howarth and Rowlands (1987) developed a texture coefficient (TC) that expresses all the main textural parameters of a rock in a single dimensionless quantity based primarily on statistical assessment. The TC makes it possible to understand the effects of a rock’s textural properties on its mechanical properties using thin sections instead of large, uniform samples. Ersoy and Waller (1995) investigated the relationship between strength and TC for limestone, sandstone, and siltstone; they also examined the effect of rock properties and TC on drilling performance. Ozturk, Nasuf, and Bilgin (2004) explored the relationship between rock quality and TC by evaluating the uniaxial compressive strength (UCS) values of limestone, basaltic andesite, and tuff. Gupta and Sharma (2012) evaluated TCs as well as the petrophysical and mechanical properties of quartzite from the lower and higher Himalayas and found a strong relationship between TC and UCS. Similarly, Ozcelik, Bayram, and Yasitli (2013) investigated the relationship between TC and various parameters in marble by applying the statistical analyses developed by Ozturk, Nasuf, and Kahraman (2014)."

Jan 1, 2019

By D. Orynbassar, N. Madani

This work addresses the problem of geostatistical simulation of cross-correlated variables by factorization approaches in the case when the sampling pattern is unequal. A solution is presented, based on a Co-Gibbs sampler algorithm, by which the missing values can be imputed. In this algorithm, a heterotopic simple cokriging approach is introduced to take into account the cross-dependency of the undersampled variable with the secondary variable that is more available over the entire region. A real gold deposit is employed to test the algorithm. The imputation results are compared with other Gibbs sampler techniques for which simple cokriging and simple kriging are used. The results show that heterotopic simple cokriging outperforms the other two techniques. The imputed values are then employed for the purpose of resource estimation by using principal component analysis (PCA) as a factorization technique, and the output compared with traditional factorization approaches where the heterotopic part of the data is removed. Comparison of the results of these two techniques shows that the latter leads to substantial losses of important information in the case of an unequal sampling pattern, while the former is capable of reproducing better recovery functions.

Aug 1, 2021

By A. J. S. Spearing, M. Sharifzadeh, K. V. Jessu

Empirical pillar design methods are commonly used in the mining industry. The parameters within which these methods are valid are frequently unknown to the user or ignored. In addition, empirical design may not consider essential parameters such as blasting effects, orebody dip and the presence of geological structures, which all adversely affect the stability of the pillars. This can result in potentially serious pillar design strength over-estimates. Although the commonly based tributary area method is generally conservative, as the spans are seldom that large relative to the depth, failing to consider other relevant parameters can result in errors. Problems associated with an under-designed pillar can range from a local pillar collapse to a catastrophic chain reaction collapse (or run). Over-designed pillars are generally safe but reduce the extraction of the orebody, thus adversely affecting the profitability of the mining operation. We used laboratory tests and numerical modelling to understand the effects of pillar orientation, blasting and the presence of discontinuities on pillar strength. Reduction factors were developed with these models to be implemented in conjunction with the existing empirical pillar design methods. For any pillar or mine design, once it is implemented, the actual performance of the system must be checked regularly by observation and monitoring and adjusted if needed. The pillar design approach outlined in this paper can better optimize the pillar mining method by considering other generally ignored but important parameters, thus improving safety, productivity, and economic aspects.

Oct 1, 2022

By G. R. Lane

A large opencast gold mining company in Africa had just completed a feasibility study for the expansion of the operations. A traditional net present value project valuation methodology had been used that showed a very positive net present value (NPV). The project team had conducted a qualitative risk assessment that identified and logged all potential project risks and had subjectively incorporated ?risk? via the discount rate and other assumption contingencies around gold price expectations, operating parameters etc. Management requested that an independent quantitative risk modelling approach be adopted to obtain a better understanding of the impact of risk on the overall project valuation and confidence level in the final valuation. A detailed project valuation model was configured in the Carbon Modelling Technology and the stochastic modelling module used to perform the Monte Carlo simulations. Analysis of historical operational performance data relating to actual achievements versus planned and budget determined the historical variability of the underlying parameters as well as variance to budget. This was done at a detailed level for mining rates and costs, processing rate, costs and recovery, and other operational efficiency measures. External market assumptions relating to gold price, exchange rate, and inflation were modelled and the dependency between them modelled using a copula. This case study will demonstrate the approach taken to building and populating the quantitative risk model and the overall results of the Monte Carlo simulation. The final valuation demonstrated that the project had a 44 percent probability of an NPV less than zero i.e. 44 percent chance of project finance loss.

Jan 1, 2012

By T. Bezuidenhout, J. D. Visagie

In recent years the requirements for a barrier system between the waste body of tailings storage facilities (TSFs) and the natural ground (NG) has necessitated the use of HDPE-lined TSFs in South Africa and other countries. The addition of an HDPE liner creates an interface between, inter alia, the tailings and surrounding soils on the footprint of the TSF. It is known that low-strength materials beneath slopes can cause slope instability. One method which can theoretically mitigate this instability of a lined TSF is the addition of stability bunds along the footprint of the TSF. Altering the profile of the footprint to include slope changes which oppose the direction of the failure creates passive slices in a limit equilibrium analysis. The passive slices actively oppose the movement of active slices, resisting the mobilization of tailings, thus greater active slice forces are required to develop a failure surface running along the liner interface. Two scenarios are presented and compared. The first scenario retains the ground profile unaltered and the second scenario includes stability bunds along the ground profile. An in-depth assessment is made of the interslice forces and the interface shear stresses for each scenario. The theoretical background is discussed in greater detail to determine the mechanisms of reinforcement provided by the bunds.

Jun 2, 2022

By Y. J. Cao

The purpose of this study was to investigate the flotation behaviour of unburned carbon in a cyclonic-static microbubble flotation column (FCSMC). The ash sample, collected from a power station in Guangdong province of China, was characterized by size analysis, X-ray diffraction, contact angle measurements, and X-ray fluorescence. The effect of the column flotation operating variables on the removal of unburned carbon from the fly ash was systematically studied. The feasibility of separating unburned carbon and ash was determined from the removal rate of unburned carbon (RUC) and loss on ignition (LOI). Within the range studied, the optimum diesel oil dosage was 1200 g/t, abies oil dosage was 600 g/t, pulp density was 20 per cent, superficial gas velocity was 1.4 cm/s, and circulating pressure was 0.20 MPa. The results indicate that the FCSMC technique is effective in removing the unburned carbon from the fly ash, which can be attributed to the generation of microbubbles and the continuous cyclonic circulation method. Under the optimized conditions, a cleaning ash with 2.13 per cent LOI and 94.21 per cent RUC was obtained.

Jan 1, 2012

By N. A. Sithole, S. A. C. Hockaday, P. J. A. Bezuidenhout

The Northern Cape Province in South Africa has high levels of annual direct normal solar irradiance and reserves of zinc (Zn) ores. The question arises as to the benefits of integrating renewable solar energy into the beneficiation routes of these reserves. The paper evaluates a novel flowsheet for the production and beneficiation of Zn in this region, maximising localised solar energy as a source for both electricity and process heat. Solar variability is discussed and the cost and benefits of thermal storage in the flowsheets are evaluated by its influence on the levelised costs of electricity and process energy over the project life-time at a possible implementation site. The results of the developed scoping model showed that solar photovoltaic integration to provide electricity for electrowinning without battery storage can lead to more than 10% cost saving on electricity over the lifetime of the project. Additional savings potential was identified when battery storage was included to enable the solar PV system to supply electricity during peak tariff periods. The solar thermal case showed the most promise with savings of 70% on heating costs for casting, while solar PV electricity without storage resulted in a 16% cost saving on heating for casting over the lifetime of the project. Solar PV electricity generation resulted in the avoidance of more than 20% of CO2 emissions from grid electricity use. Solar thermal heating can avoid up to 80% of the CO2 emissions associated with grid electricity use for remelting of Zn cathodes for casting. The CO2 emissions are indirect and not subject to South African carbon tax. Keywords: Solar process energy, zinc beneficiation, flowsheet evaluation

Jan 1, 2020

By Y. Ren, B. Yang

The magnetic field characteristics due to electromagnetic stirring in the secondary cooling zone of an extra-thick slab during continuous casting are numerically determined using Maxwell's equations, with particular emphasis on the distribution of magnetic induction intensity and electromagnetic force, as well as the influence of process parameters on the magnetic field. The orientation of the electromagnetic force is the same when the electromagnetic stirrers at the 30° and 60° posistions of the arc-shaped slab are powered in the same direction; otherwise, the orientation is opposite. The magnetic induction at the centre of the section of the stirrer's central axis at the 30° positio, as well as the current, frequency, and fitting formulae, are as follows: B = {0.075I.(1/A)-0.3} mT and B = {-1.75f.(1/Hz)+22} mT. The electromagnetic force and current fitting formula at the central point of the B-B section is F = {0.03168I2.(1/A2)-03.762I.(1/A)+326.7} N/m3, and the fitting formula of electromagnetic force and frequency at the centre point is divided into two segments. The first takes the form of a parabola: = {-21((f-4.3).(1/Hz)2)+970} N/m3, and the second segment is negative linear: F = {-1.65f.(1/Hz)+51.5} N/m3.

Apr 16, 2024

By J. van der Walt, W. Spiteri

Flyrock remains a significant threat to the health and safety of mine employees and integrity of infrastructure, as well as to the safety of the neighbouring communities and their property. This investigation was motivated by the general lack of fundamental research and mathematically quantifiable data in the literature regarding the relationship between blast design parameters and their impact on flyrock. The focus was to develop a concept that can be used to mathematically quantify the trajectory of flyrock resulting from a blast, which can be used for future research. The ultimate goal for this technique, once it has been fully developed, is to: ➤ Enable mining operations to generate a database with accurate historical flyrock measurements resulting from their blasting operations ➤ Allow research teams to conduct scientific investigations into flyrock and the impact of various blast design parameters ➤ Generate point-cloud data to visualize blasts and flyrock in a virtual reality environment for training and education purposes. This paper summarizes a conceptual technique and preliminary fieldwork that was carried out to determine the technique’s feasibility and motivate further development. The results show conclusively that a modified photogrammetric technique is capable of capturing flyrock data for further processing and analysis. The data acquisition procedure can, at this point, be used to meet the first aim of the project, namely to gather a field database of historical flyrock generation. Further development of the technique is ongoing and it is envisioned that the scientific-based technique will provide a method whereby future flyrock studies will be comparable and that assumptions will be limited.

Apr 5, 2023

By L Dyer, G. J. Wilkie, P. Walters, B Tadesse, L. Keeney

Grade Engineering® is a term trademarked by the Cooperative Research Centre for Optimising Resource Extraction (CRC ORE) and includes five key levers for upgrading ores and rejecting waste prior to expensive downstream comminution and mineral processing. These five levers include natural deportment, induced deportment, bulk sorting, particle sorting and gravity separation. Over the past ten years, CRC ORE has progressed a range of technologies that exploit these levers from laboratory proof of concept through to large scale demonstration and validation. This paper details the work carried out by CRC ORE and Curtin University for assessing the amenability of an ore for its natural deportment and particle sorting attributes in an Integrated Screening and Particle Sorting (ISPS) Grade Engineering® process. ISPS is seen as a preferred method for Grade Engineering® as compared to individually operated unit operations as the benefits of each can be complementary. Furthermore, it is suggested that integrating the two levers has two important impacts: 1. Firstly, there is a risk that isolated particle sorting test results will be misinterpreted as being representative of the full sample without considering the mass balance impact of high-grade material that might have been lost in the fines fraction. This fine fraction will not be detected through the particle sorter. 2. Secondly, and potentially of more valuable impact, is that the opportunity may exist to upgrade the feed first through determining if there is a concentration of high grade to the fine (or coarse) fraction which can be separated through screening. Undertaking screening in the preparation stage of the particle sorting process will enable analysis and separation of the fine or coarse fractions of a rock mass. The result of this study provides the mining industry with an independent framework for undertaking an Order of Magnitude (ISPS) Grade Engineering® assessment on a range of constituent ore types. Keywords: Grade engineering, particle sorting, grade by size fractionation

Jan 1, 2020

British Mining Fields, by J. E. Metcalf. Published by the Institution of Mining and Metallurgy, London, 1969. Price 50s. (Students, 30s.). A 100 years or so ago Britain's mining industry led the world in the production of coal and base metals. Although she still maintains a sizeable-and, under the circumstances, remarkably progressive-coal mining industry, her production of most other base minerals has long since been dwarfed by mining fields in the Americas Africa, Australia and the U.S.S.R. Nevertheless the story of mining in Britain is of wider interest than the present scale of operations there might suggest, if only because the domestic British mining industry has in terms of finance, technology and manpower been the fons et origo of many highly productive mining fields outside Britain, including the Witwatersrand goldfields. British Mining Fields was published by the Institute of Mining and Metallurgy to give delegates attending the Ninth Commonwealth Mining and Metallurgical Conference a succinct account of mining in Britain. The main emphasis is on underground mining of base minerals-treated regionally-with separate chapters on coal and gypsum. The author strikes an admirable balance between historical aspects, geological origin and environment of ore deposits, mining methods and economic factors, and provides a few key references for those who wish to make deeper studies. This is exactly the sort of booklet one often wishes were available on South African mining.