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By M D. Taylor, G Duclaux, K Atkinson, L A. Fisher, A R. Latham, M F. Gazley, S J. de Beer, C M. Tutt

Geological logging by mine and exploration geologists involves the application of a logging code that requires a geologist to make a subjective decision to classify a particular rock unit. This will most likely result in inconsistencies in logging that will be difficult to monitor or assess over time. A potential solution to this problem is to have an objective method to determine the true nature of a given rock unit. This can be achieved using portable X-ray fluorescence technology (pXRF), as large geochemical data sets can be collected rapidly and at low cost. Plutonic Gold Mine (Plutonic), Western Australia, has a growing data set of more than 150 000 pXRF multi-element analyses from core and underground face samples, reconciled to Au fire-assay concentration, and logging codes. This study investigates and statistically validates the consistency with which the logging codes have been applied at Plutonic for the last four years, with respect to both Au distribution and other elements. In doing so, we have developed a schema that allows objective logging to occur once core has been sent for assay and analysed by pXRF. While far from replacing the geologist in the field, this is a complementary method that adds significant value to a data set.CITATION:Gazley, M F, Tutt, C M, Latham, A R, Duclaux, G, Fisher, L A, Taylor, M D, de Beer, S J and Atkinson, K, 2013. Objective geological logging using geochemical multi-element data - Plutonic Gold Mine, Western Australia, in Proceedings World Gold 2013 , pp 455-462 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By N L. Turner, K Ehrig, V Liebezeit, D J. Robinson, L L. Kuhar, N Francis

Conventional industry tests used to determine leach recoveries are often fully monitored and may be time-consuming and expensive. Such tests may be limiting in geometallurgical applications where large numbers of samples are required to be processed for characterisation of an ore deposit. BHP Billiton currently use a fully instrumented leach test for characterisation of Olympic Dam uranium-rich samples. Researchers at the Commonwealth Scientific Research and Industrial Organisation (CSIRO) were approached to develop an alternative to these full-scale leach tests that could allow for the ranking of samples in terms of their leachability. The novel geometallurgical test was required to use samples of small mass and be affordable and rapid.Three leach test protocols were pursued in developing the small-scale tests. Kinetic leach tests were performed using mild conditions at higher pH, low temperature and low oxidation reduction potential, moderate conditions at intermediate pH, temperature and oxidation reduction potential and aggressive conditions at lower pH, higher temperature and higher reduction potential.This paper presents results from 44 leach tests on 11 samples with varying uranium mineralogy. The developed small-scale tests correlate well with data from the more costly conventional industry laboratory tests, indicating the possibility of using this alternative test as a geometallurgical leach proxy. Simple regression analysis confirmed the importance of pH, reduction potential and temperature on uranium extraction. Experimental data were fitted to published leach models to predict uranium leach extraction for a range of operating conditions.The ultimate aim of the test work is to combine a limited number of large-scale calibration tests, a large number of small-scale geometallurgical tests and leach models for geometallurgical sample characterisation and evaluation of a wide range of scenarios or processing options.CITATION:Turner, N L, Kuhar, L L, Francis, N, Liebezeit, V, Ehrig, K and Robinson, D J, 2013. Development and testing of a small-scale uranium leach for geometallurgical applications, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 345-350 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By K Esmaeili, S Aziznejad

Impact-induced rock fragmentation is a mechanism that is commonly used for rock breakage in drilling and crushing. Additionally, rock fragmentation by blasting is frequently used in rock excavation operations. Experience shows that the presence of discontinuities can significantly influence the impact-induced damage and fragmentation of rock. Quantification of the response of jointed rock masses to impact loads is complicated by the fact that the available laboratory tests are mainly designed for aggregates or intact rocks. It can be argued that neither of these tests adequately represent a jointed rock mass. This paper presents the results of a series of numerical simulations used to investigate the influence of pre-existing discontinuities on the impact-induced fragmentation of rock masses. The methodology includes determination of the static and dynamic mechanical properties of a rock unit by conducting a series of laboratory tests on intact rock samples collected from a quarry in Canada. A 2D distinct element code, Particle Flow Code, was used to generate a bonded particle model in order to simulate both static mechanical properties (uniaxial compressive strength, elastic modulus, Poisson’s ratio and indirect tensile strength) and dynamic mechanical property (drop weight tensile strength) of the intact rock. The calibrated numerical model was then used to construct large-scale synthetic rock mass samples by incorporating discontinuity networks of different intensity into the bonded particle model. Finally, the impact-induced fragmentation inflicted by a rigid projectile particle on the jointed rock mass samples, simulated by a synthetic rock mass model, was determined. More fragmentation was observed for the rock mass samples with higher joint intensity.CITATION:Aziznejad, S and Esmaeili, K, 2015. Effects of joint intensity on rock fragmentation by impact, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 377–384 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M Darvall

Magnetite ore blending has yielded signifi cant performance improvements in OneSteel’s magnetite concentrator. The magnetite concentrator beneficiates magnetite ore from the Iron Magnet Deposit and produces concentrate, which is pelletised, then fed to the OneSteel Whyalla blast furnace. Concentrator feed variability severely detracts from the concentrator’s performance, affecting both concentrate yield and grade, which impacts on all downstream processing costs.A coordinated approach has integrated mine planning, geological modelling and grade control, to minimise concentrator feed variability, through effective ore blending throughout the mining and stockpiling process.Mine planning personnel design shots that extend the full width of the orebody and hence across the stratigraphic profi le. Based on geological information contained in block-outs and in consultation with Geology, the Grade Control team allocates material to each primary stockpile, potentially from every stratigraphic domane in the orebody. This ensures primary stockpiles are designed with maximum practical homogeneity and consistency.Using only primary movement, the allocated ore is stockpiled in a layer-cake fashion. The ore is pimple dumped across the width of the stockpile footprint and on completion of a layer, it is dozed flat with an access ramp that allows dumping to commence on the next lift. The primary stockpiles are reclaimed normal to build direction and the magnetite is crushed, all in, to a concentrator feed stockpile.The ore is sampled at the crusher from a falling stream cut. These assay data, are used for benchmarking and control charting the grade and variability of concentrator feed stockpiles. The concentrator feed stockpiles have demonstrated a statistically signifi cant reduction of within pile variation, between pile variation and pile to pile variation, primarily attributable to the development of ore blending. The concentrator has seen sustained, improved performance as a direct result, which translates into lower concentrate cost per tonne and improved yield and quality.

Jul 11, 2011

Prior to 1975, most geochemical drainage surveys for gold were based on analyses for pathfinder elements, such as As and Cu, rather than direct analysis for gold, for two reasons. Firstly, analytical methods lacked the required sensitivity and precision to determine gold abundance at background levels in stream sediments (usually in the range 1 - 10 ppb). Direct analysis was also inhibited by concern about the potential for gross sampling error, brought about by the dispersion of gold as rare discrete particles of the extremely dense native metal. This sampling error, commonly termed the 'nugget effect' has two components: erratic distribution of the element within the stream environment, related to hydraulic factors, and the difficulty in taking representative samples, both in the field and later in sub-sampling for analysis. In more recent years the collection of very large samples was commonly advocated to overcome the sampling problem (Hams, 1982; Nichol, 1986).Two methods have been widely used to evaluate the gold content of bulk samples (Elliott and Towsey, 1989). The preparation and analysis of heavy mineral concentrates has in recent years been largely superseded by the leaching of gold contained in bulk samples by cyanide, commonly termed the BLEG (Bulk Leach Extractable Gold) or BCL (Bulk Cyanide Leach) methods. The terms BLEG and BCL are essentially interchangeable and the latter will be adopted for the remainder of this paper. The strengths and weaknesses of these two techniques were compared with conventional total gold analysis on fine fraction (

Jan 1, 1976

The Mesozoic intrusive rocks in southeastern coastal China can be divided into three intrusive suites, and they can be brought into corresponding with four cycles of volcanic activity. This paper describes their time-space relation with volcanic rocks, and their geochemical characteristics. Data from the Mesozoic volcanic-intrusive. complex rocks in Eastern Zheijiang, Eastern Fujiang and Eastern Guangdong show distinct regional differences, both within and tectonomagmatic activity regions. The southeastern coast of China involves four tectonomagmatic activity regions. They have many differences on the nature of magma source regions, activity patterns of magma, time-space distribution, petrography and petrographic facies association of volcanic and intrusive rock and mineralization.

Jan 1, 1990

By C Hall, K Williams, B Keogh, S Wong

Cannington mine is a silver lead zinc operation located in north west Queensland. The operation has been in production since 1997. Ore is primarily moved through an underground material handling system comprising of a crusher, conveyor and hoist. The underground crusher and conveyor system were sited in lower grade ore when the mine was first commissioned. As Cannington is now a mature operation, this ore is considered run of mine and stoping progressed into the crusher exclusion zone. As the stoping fronts advanced there was increased damage on the crusher chamber and infrastructure. In response to monitoring data, the crusher monitoring system was significantly upgraded in 2016. The monitoring system included rock mass and infrastructure instrumentation. It improved the understanding of stress impacts and mechanisms driving the damage within the chamber. It allowed the site geotechnical team to respond to changes utilising ground support, mining sequences and increased levels of monitoring. As stoping and damage to the rock mass continued, so did the process of responding to monitoring data. Ultimately, the monitoring system enabled a safe and controlled closure of the chamber. CITATION:Williams, K, Keogh, B, Hall, C and Wong, S, 2018. Monitoring as an input to support and sequence design, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 446–452 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Lawrence L. J

The Australian Broken Hill Consols Mine, situated some 600 yd east of the main Broken Hill line of lode, is noted for its rich ores of silver. In contrast to the vast conformable orebodies of the Broken Hill field, the Consols lode occupies a narrow fissure dipping to the south west at angles increasing from 240 through to vertical and transgressing the strike of the metamorphosed country rock at an oblique angle. This feature, together with the abundance of calcite and siderite and the virtual absence of silicate minerals in the gangue, has led to its classification as an orebody of the Thackeringa type (King, 1953). Recorded production during the period 1890 to 1903 is given as 845,000 oz of silver and 20 tons of lead.The unusually rich silver values of the Consols lode were concentrated at the intersection of the fissure with beds of amphibolite, whereas in the adjacent schists and gneisses the lode became markedly impoverished. From the surface to a depth of some 120 ft extensive surface oxidation had occurred, resulting in the breakdown of siderite and its replacement by limonite and associated manganese oxides.Silver halides, dyscrasite, acanthite and partly oxidised tetrahedrite were the main silver minerals in this zone. With increasing depth the lode material gradually reverted to minerals representative of the hypogene zone.The only previous work specifically on the mineralogy of the Consols lode is that by Smith (1922), one time manager of the mine. His zeal as a mineral collector resulted in much valuable information being available on the distribution of the minerals. More recently, Garretty (1943) noted the...

Jan 1, 1962

By R Yang

This paper presents a fragmentation model for large production blasts in an open pit or underground environment. The paper shows that the particle velocity is directly related to pressure, strain, and strain rate and so it can be considered as driving force and mechanism of rock fragmentation. This is supported by the fact that a vibration with a larger peak particle velocity (PPV) generates larger disturbance in rock and so finer fragmentation or more blast damage than a low PPV. The crack distribution in rock from impact is based on findings from previous researchers (Seaman, Curran and Shockey, 1976; Liu and Xu, in press). The fragmentation size is calculated at three-dimensional grid points within a blast. The fines and oversized blocks are calculated explicitly – the fines generated close to blastholes and big blocks far from boreholes are modelled naturally. The multiple blasthole fragmentation (MBF) model takes surveyed irregular geometry of the free face of a blast as the calculation boundary. The MBF can model fragmentation with over one million grid points. Examples of the model’s field comparison are also included.The PPV at a calculation grid is estimated based on the same approach used for the near field non-linear vibration model (Yang and Scovira, 2007). The method is based on the dominant charge for a calculation grid point, non-linear charge weight superposition within a charge and from multiple charges, strain wave broadening, and amplitude attenuation with distance from a charge segment. The blasthole confinement affected by earlier firing charges is also taken into account.The MBF model inputs from blast design, such as: location and orientation of each blasthole, stemming length, blasthole diameter, multiple decking, bench height, initiation sequence, etc. It models the effect of the delay and its scatter in each blasthole on fragmentation and has a statistical modelling capability for geological random variation on attenuation of particle velocity wave. The wave reinforcement due to instantaneous waves arriving or diminishing cooperative contribution due to long delay intervals between charges is also simulated.The results are displayed in 3D volumetric plots, contour of fragmentation in cross-sections, and size passing curves for a whole blast or a region of the blast.CITATION:Yang, R, 2015. A multiple blasthole fragmentation model – its concept, formulation, capability and field comparison examples, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 177–186 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Gravity gold recovery has been practiced for thousands of years, making it one of the oldest forms of mineral processing. Gold is 19 times heavier than water although the barren rock is generally only 2.7 times heavier. Any potential gold ore needs to be characterised to assess its amenability to a gravity recoverable gold (GRG) process based on well planned and executed test work. Scale up considerations need to be considered in designing a gravity circuit. The economic impact of a gravity circuit should be justified based on the installed cost and likely benefits. Maximising gravity gold recovery results in a faster cash flow, lower operating cost per ounce and higher overall gold recoveries compared to the several weeks required to recover gold adsorbed onto carbon. The advent of centrifugal concentrators such as the Knelson and Falcon, coupled with intensive leaching of concentrates (ILR), has revolutionised gravity gold circuit designs. Considerations associated with the sizing of the centrifugal machines and the percentage of the circulating load (bleed) that should be processed is discussed in this paper. The trends with gravity circuit layout, engineering, as well as optimum dumping cycles, are important areas which require close consideration. Key aspects of these are presented in this paper. There are a number of circuit configurations to be considered, including the integration of different gravity concentrators. Other gravity process design considerations such as fewer modules, the effect of equipment size and enhancement of process efficiency using preconcentration, together with factors that affect OPEX and CAPEX are addressed. Practical considerations of maintenance, security from theft, minimisation of risk and water balance considerations are discussed using different equipment and circuit configurations. The trend towards using gravity recovery in flotation plants is also reviewed. A number of examples are cited and good design aspects highlighted.

Aug 1, 2010

The Southern 'B' lode orebody at the New Broken Hill Consolidated Limited (NBHC) mine, Broken Hill, is a continuation of the zinc-rich orebody that was first mined in NBHC in the 1940's. Preliminary diamond drilling in the early 1960's resulted in sufficient information to delineate the southern extension of the presently mined 'B' lode orebody, In 1966 the sinking of a 7.3 metre diameter circular shaft (No. 3 Airway) was commenced to improve the ventilation of the southern extremities of existing workings and to provide a base to further explore and develop the orebody extension. Development on four levels was started in the early 1970'.s to link the existing workings with the new shaft. Three possible mining methods - sublevel open stoping, loader cut and fill with ramp access and sublevel caving - were investigated and the decision was made to mine the orebody by transverse sublevel longhole stopes and pillars with trackless equipment and ramp access between the major working levels.

Jan 1, 1977

By B H. Yin, S Mendoza, M Nusheh' C W Bumby, A Zhang

Hydrogen-direct-reduction of iron ore in a vertical shaft furnace is a potential process that could significantly reduce CO2 emissions from the steel industry. This approach requires the pelletisation of iron ore fines, which then undergo high temperature induration to strengthen the pellets before they can be fed into the shaft furnace. Here we report on investigations into the disc-pelletisation behaviour of New Zealand titanomagnetite ironsand, and its subsequent induration and hydrogenreduction behaviour. Initial studies focused on the effect on pellet strength of varying ironsand particle size and induration conditions using bentonite and a commercially sourced carboxymethylcellulose binder. Green pellets formed with ironsand of average particle size of 65 μm exhibited optimal strength. The compressive strength of these pellets after induration at 1200°C for 2 hrs in air was measured to be 976 N. Interparticle bonding within the indurated pellets occurs due to a combination of titanohematite recrystallisation (from oxidation of titanomagnetite), and the formation of a liquid bonding phase due to interdiffusion with the bentonite and subsequent melting. Further investigation with various binders showed that a combination of both organic and inorganic binders was essential to achieve optimal pellet strength. Carboxymethyl-cellulose binders provides green strength, whilst inorganic binders such as bentonite promoted high indurated pellet strength. Hydrogen reduction tests in a thermogravimetric furnace showed that all the pellets could achieve a maximum reduction degree of 97 per cent at 1100°C, indicating that the different pellet preparation procedures had no significant effect on reducibility. Pellet recipes developed in this work are now being used to investigate vertical shaft hydrogen-DRI processing of NZ ironsand in a kg-scale laboratory reactor.

Sep 18, 2023

Iron formation-hosted iron ore deposits account for the majority of current world iron ore production and consist of three classes: unenriched primary iron formation with typically 25 to 45 wt per cent Fe; martite-goethite ore formed by supergene processes, with abundant hydrous iron oxides containing 60 to 63 wt per cent Fe; and high-grade hematite ores thought to be of hypogene or metamorphic origin overprinted by subsequent supergene enrichment with 60 to 68 wt per cent Fe.Individual iron ore deposits range from a few millions of tonnes to over two billion tonnes at >64 wt per cent Fe, although most are within the range of 200 to 500 Mt. In the Hamersley Province of Western Australia, martite-goethite ores are largely developed in the Marra Mamba Iron Formation, although high (>0.08 per cent P) phosphorous mineralisation is also well developed in the stratigraphically higher Brockman Iron Formation. Whilst the vast majority of high-grade microplaty hematite ore is best developed in the Brockman Iron Formation, this paper provides the first textural evidence of locally significant microplaty hematite mineralisation in the Nammuldi Member of the Marra Mamba Iron Formation, in the Chichester Ranges at the Christmas Creek, Cloud Break and Mount Nicholas prospects. Petrographic studies have identified a high-grade Fe texture composed of nanometre scale plates of hematite in mineralised sections of primary microplaty hematite deposits in the Pilbara and elsewhere, well below the normal depth of weathering or dehydration. The population of nanometre to micrometre scale hematite plates is interpreted to represent various stages of nucleation, crystallisation and progressive growth of hematite from the primary ore-forming fluid in areas that were once iron-rich carbonates or silicates in the BIF.

Jan 1, 2005

By Grantham DL

ABS'TRACT For a number of years research efforts have been directed towards improving the efficiency of sampling and analysing coal mine roadway dusts. In the past decade the practicality of rapid, on site analysis of the incombustible content of these dusts using a radioactive technique has been receiving close attention both in Australia and overseas. Accurate measurement of the total incombustibles present is only possible by time consuming chemical methods. As the densities of the solid incombustible materials are greater than that of coal, they absorb a higher proportion of incident low energy gamma radiation than does coal. The amount of such radiation "back scattered" from mine dust samples is therefore inversely related to their average densities, and hence to their incombustible contents. This phenomenon can be used as a measure of incombustible content by employing an appropriately designed and calibrated instrument.

Jan 1, 1981

With the sinking of the No. 3 Shaft at North Broken Hill Limited, it was necessary to construct adjacent to the shaft a new changehouse for mining and surface personnel.It was also probable that as the older sections of the North and British leases were worked out, all employees at present working in these sections would be transferred to the No. 3 Shaft area. This could ultimately result in all personnel employed by North Broken Hill Limited being concentrated in this area, requiring the construction of new administration offices, workshops, mine store, etc., also in this area.

Jan 1, 1957

By Lewis PC, Carr GR, Dean JA, Glen RA

The Lachlan Fold Belt (LFB) is a complex orogenic belt which developed in Early to Mid Palaeozoic time. A number of orogenies and more localised deformational events affected the region. A simplified classification scheme for the diverse gold deposit types is proposed, subdividing primary mineralizing processes into four categories: volcanism (epithermal and volcanogenic deposits), igneous intrusion (subvolcanic/porphyry style, skarn and magmatic deposits), metahydrothermal processes (deposits generated during metamorphism and regional deformation) and hydrothermal-distal processes (deposits generated by poorly understood, generally remote large scale hydrothermal processes). Major gold deposit associations include epithermal and porphyry style deposits in Ordovician-Early Silurian shoshonitic andesite sequences; volcanogenic base metal-gold deposits in Silurian rift or basin felsic sequences; vein deposits in Late Silurian and Early Devonian S and I-type granitoids; deposits in Early Devonian sedimentary rocks of the Cobar Basin probably generated by metahydrothermal processes during basin closure and cleavage formation; deposits associated with serpentinite; and metahydrothermal quartz vein deposits in folded sedimentary rocks.Studies of host rock geochemistry suggest a relationship between magma types, gold enrichment and mineralization particularly in shoshonitic sequences and Early Devonian granitoids of the Boggy Plain Supersuite. Structural studies indicate the importance of thrust type structures and detachment faults in generation and location of gold mineralization. Lead isotope initial ratios help define metallogenic associations and a number of distinctive isotope "signatures" have been established.

Jan 1, 1990

By de Vries D, Wilson EG, Henderson GAM, Carter EK

Canberra is a planned city in which the natural environment, rather than existing development and land tenure, has until recent times at least, imposed the major constraints to development. Even redevelopment poses fewer problems than for most cities. Geological conditions have, therefore, played a significant role in determining its shape and layout. The Canberra experience has relevance for major new mining and engineering projects. The role of engineering geologists and geophysicists in Canberra's development is described, and the problems arising from the geological environment are illustrated by several case histories. Four aspects are addressed: pre-development urban geology; major engineering projects; resources evaluation, including groundwater; and post-development problem-solving. The Australian Capital Territory lies within the Palaeozoic Lachlan Fold Belt. Within the ACT the belt is composed of folded and faulted metasiltstones, metasandstones and acid volcanics, intruded by a major granitic pluton. Some limestone lenses occur. The region has been part of a land mass since Late Devonian times and landscape evolution has been very complex. Geological features of special geotechnical significance include deep but variable weathering, with slight to moderate weathering along faults to at least 70 metres depth in places, and consequential foundation problems; close jointing; weathered limestone lenses with solution cavities containing clay and water; confined aquifers containing artesian water in scree deposits flanking hills; the presence of pyrite; and poor quality and low volumes of groundwater.

Jan 1, 1986

By Beer G

The recent re-emergence of an Integral Pressure Stripping system which operates with both cell and column in closed circuit at elevated temperature and pressure, requires no cyanide in the eluate solution and has greatly reduced carbon reactivation requirements in seen as a progressive step in this area. Several of these re-configured IPS systems have been placed in service in Australia and overseas in the last three years, with the first of the new generation units constructed and commissioned by Como Engineers Pty. Ltd. at Mt. Fisher in the East Murchison of W.A. in September 1987. This plant was relocated to a new ore body at Darlot W.A. in February 1989. Use is made of a data base of raw plant performance figures from both Mr. Fisher and Darlot and its performance compared with other operating plants. Initial commissioning difficulties of the Mt. Fisher prototype and dis- cussed together with the modifications and operational procedures required to overcome these problems. Stripping times of less than 6 hours at 145 degrees have been achieved with barren carbon values less than l O ppm from loaded carbon values above 3000 ppm and with cell pass efficiencies reaching 90 per cent.

Jan 1, 1991

By Scott IR

In stratigraphic orebodies, estimation of footwall and hangingwall location is often of more importance than grade estimation. Contoured grade estimates often produce smeared boundaries and the use of accumulations and thicknesses as variables re-introduces the original problem: location of the point at which the estimate is to be made. The paper introduces statistical and geostatistical techniques for the solution of the problem and illustrates the techniques with a case study from Mount Isa, one of the world's largest producing silver-lead-zinc deposits. Solutions for calculating variograms in orebodies of variable dip, strike and plunge are presented together with relative variograms for individual metals, metal accumulation and orebody thickness. Optimal methods for hangingwall and footwall location are introduced and illustrated with an example. Orebody boundaries are then kriged after which individual metal grades are kriged within the estimated boundaries. The boundary estimates are compared with manually interpreted boundaries and known boundaries in mined-out areas. Grade and tonnage estimates are compared in mined-out areas.

Jan 1, 1986

By Hughes J. C

THE smelting plant consists of five large furnaces operating in the treatment of current flintered material, and one small furnace operating periodically in the treatment of copper dross and antimonial slag produced in the lead-refining process.he following table supplies the leading dimensions and details of the large furnaces:-(a) Crucible - Dimensions 17 ft. 2 in. long x 4 ft. wide x 2 ft. 3 in deep. Capacity - 30 tons lead. Class of lining - firebrick. No. firebricks required - 3000.(b) Crucible Tank - Dimensions 20 ft. 6in. long x 10 it. 6 in. Wide x 4 ft. 3 in. deep. Material - 1/2 in. mild steel.(0) Jackets - Dimensions 6 ft. long x 19 in. wide x 6in. thick. Material - Cast-iron. Average life - 2 years. Number per side - 11, with 13-in. bosh. Number per end - 3, with 9-in. bosh.

Jan 1, 1922